Computational Study of Hot Gas Injection (HGI) into an

Research ArticleComputational Study of Hot Gas Injection (HGI) into anIronmaking Blast Furnace (BF)

Zhaoyang Li 123 Yixiong Feng4 and Aimin Wang25

1School of Mechanical Engineering Zhejiang University Hangzhou 310027 China2Shandong Iron and Steel Group Co Ltd Jinan 250101 China3Center for Simulation and Modelling of Particulate Systems Southeast UniversitymdashMonash University Joint Research InstituteSuzhou 215123 China4State Key Lab Fluid Power amp Mechatron System Zhejiang University Hangzhou 310027 China5Hengda Fuji Elevator Co Ltd Huzhou 313009 China

Correspondence should be addressed to Zhaoyang Li lizhaoyangshan-steelcom

Received 9 April 2021 Accepted 28 September 2021 Published 14 October 2021

Academic Editor Jianguo Wang

Copyright copy 2021 Zhaoyang Li et al )is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Blast furnace (BF) ironmaking is the most important process that produces hot metal (HM) from iron-bearing materialscontinuously rapidly and efficiently To date the process is considered to have reached its limit in view of the achieved highprocess efficiency In addition the required high-quality materials are expensive and gradually getting depleted Hot gas injection(HGI) into the shaft of the BF is an emerging technology recognized potential to solve the aforementioned problems However sofar limited information and studies are available most of which are preliminary studies with regard to the feasibility andaerodynamics of the technology)is hindered the understanding and thus the effective use of this technology)is work presentsa numerical study of the multiphase flow heat and mass transfer in a BF by a CFD-based process model )e effects of injectioncomposition in terms of CO and CO2 contents in HGI are studied first)e calculated results reveal that HGI of 100 CO deliversthe best BF performance )en the effects of key variables in relation to HGI of 100 CO including position rate andtemperature are systematically studied )e in-furnace states and overall performance parameters have been analysed in detail)e results show that through appropriate control of the injection variables it is possible to achieve improved BF performanceincluding low fuel rate and high productivity which are considerably affected by the HGI parameters)e BF process model is alsodemonstrated to be a cost-effective tool in optimizing the key variables of HGI in BF for obtaining optimum process efficiency

1 Introduction

)e blast furnace (BF) ironmaking process is the mostimportant technology by which hot metal (HM) is con-tinuously rapidly and efficiently reduced from iron-bearingmaterials [1] )e process heavily relies on the use of car-bonaceous materials including coke and pulverised coal(PC) to generate the required energy which makes up morethan 70 of the energy consumption and production cost inan integrated steelwork In addition the necessitated coke isan expensive raw material and gradually getting depleted)erefore there is a considerable amount of social andeconomic concerns over the current BF ironmaking process

However it should be pointed out that after 200 years ofdevelopment the process is recognized to have approachedits limit in view of the achieved high process efficiencyConsequently any considerable amount of fuel reductiononly based on the optimization of the traditional BF isdifficult to attempt [2 3]

In recent decades much attention has been given to theimplementation of new technologies on the BF )e newtechnologies include the hot charge of burden materials[1 4 5] injection of novel matters such as PC [6] oil [7]natural gas [8 9] and hot gas [10ndash12] and use of new burdenmaterials including highly reactive coke [13 14] and carboncomposite pellet [15] )ese technologies have been

HindawiMathematical Problems in EngineeringVolume 2021 Article ID 3344143 16 pageshttpsdoiorg10115520213344143

examined at various levels and proved to be useful forimproving BF performance Among these technologies thehot gas injection (HGI) into the BF is considered useful dueto its possible advantages [1 16] )e hot gas can be gen-erated from the combustion and reforming of cheaper fuelmaterials and off-gas within the steelwork which is moreflexible and economical than the combustion of coke andPC It can be used to intensify the smelting of burdenmaterials and reduce the fuel rate Compared with fossil fuelinjection HGI avoids the decreased adiabatic flame tem-perature and the generation of unburnt powders In addi-tion HGI can be flexibly implemented at the BF shaft whichavoids the flow of high-speed gas in the low permeability wetzone

HGI was first introduced by Lance in the 1920s in whichit was used to partly replace the reducing gas generated fromcombustion of carbonaceous materials in the raceway [17]After that little progress wasmade until middle 1960s Usingan experimental BF (EBF) with a hearth diameter of 46mHGI of reformed gas at 1000degC was tested in Belgium [17] Inlate 1970s Fink employed this technology on an oxygen BF(OBF) to solve the thermal shortage problem [18] After thatinvestigations have been intensively performed by variousmethods such as cold model [19] experimental scale[11 20 21] and commercial scale [10 22] BFs as well astheoretical calculation [16 18 23ndash25] continuum models[10 26ndash28] and discrete models [29 30] )e EBF (innervolume 32m3) [21] and numerical model studies [27]showed that HGI should contain less CO2H2O due to thestrong endothermic effect of carbon solution loss reactionand water gas reaction )e injection position is better tolocate at the bottom of the thermal reserve zone in the BFshaft so that the reaction products (CO2H2O) would notundergo severe solution loss [1 21] Besides the temperatureof injected gas should be at around 1000degC [1 19] tomaintain the temperature profile in the BF A number ofstudies showed that HGI improves BF performance in viewof decreased coke rate and increased productivity[21ndash23 31] It was also revealed that the penetration depth ofinjected gas is in proportion to the volume ratio of injectedgas to gas generated from tuyere [1 19 29] By using an EBFit was shown that shallow penetration of HGI leads to lessimproved BF performance [11] Recently HGI is morefrequently employed on the OBF as an enabling technologyto address the thermal shortage phenomena in the upperfurnace with several typical OBF processes established[18 22 24 25 32] It is also considered as an essential partfor realizing the zero-carbon footprint OBF process throughinjection of recycled top gas after CO2 capture and storageWith those efforts HGI has been considered promising andis currently adopted by two world-class projects aiming lowcarbon production ie ULCOS in the European Union [17]and COURSE50 in Japan [11]

It is clear that the control of the operational parametersof HGI including injection composition position tem-perature and rate has significant impact on the BF per-formance However thus far a comprehensive studyregarding the effects of key operational parameters of HGIon BF inner states and overall performance indicators is yet

available )is hinders the understanding and therefore theeffective use of the technology Considering that the iron-making BF is a complicatedmultiphase reactor accompaniedwith high temperature and hazardous conditions instru-mentation is difficult to access its inner states [33] Also it isdifficult to use theoretical and experimental methods toconduct investigations comparable to a real BF situationAlternatively numerical models are playing an increasinglyimportant role in investigating the BF ironmaking processsee eg the reviews by different investigators [34ndash37]Basically the methods can be either discrete or continuum[38 39] Compared with the discrete models the contin-uum models are considered more suitable for processmodelling due to its computational efficiency )is workfor the first time presents a comprehensive numericalstudy of the effects of HGI on BF performance with respectto key performance indicators including injection com-position position temperature and rate First the BFprocess model used in this is briefly introduced )en theeffects of HGI compositions in terms of varying CO andCO2 content are performed Based on the results theoptimumHGI composition is thus identified to improve BFperformance After that a systematic study with respect tothe key HGI variables including position rate and tem-perature using the identified optimum HGI composition isconducted Detailed analysis with respect to the flow heatand mass transfer as well as thermochemical phenomena inthe BF is carried out for optimizing the injection opera-tional parameters

2 Methods

)e present mathematical model is a steady-state axisym-metric multifluid model It considers the region of a BF fromthe slag surface up to the burden surface )e phases con-sidered including gas solid and liquid Each phase in themodel is described by separate conservation equations ofmass momentum and enthalpy with the key chemicalreactions considered Gas is described by the well-estab-lished volume-averaged multiphase NavierndashStokes equa-tions [39] Solids are assumed to be the continuous phasethat can bemodelled based on the typical viscousmodel usedin multiphase flow modelling [39 40] coupled with themethod proposed by Zhang et al [41] for determination ofthe deadman boundary General convection-diffusionequations are applied to describe heat and mass transferamong the different phases)emodel is in principle similarto other BF process models developed by different investi-gators [4 40 42ndash49] and moreover it is able to model thelayered burden structure in lumpy zone and cohesive zone(CZ) [40] as well as the varying stockline [40] as well as stockline variation [4] )e details of the model and relevant nu-merical techniques are available elsewhere [4 40 41 46 50 51]and are not detailed in this paper for brevity )e governingequations key chemical reactions and transfer coefficients aresummarized in Tables 1 and 2 In this work the model ismodified so that it is able to handle BF with HGI with varyinginjection composition position rate and temperature withinwide ranges

2 Mathematical Problems in Engineering

)e model used in this work is well-developed and hasalready been validated at different levels Firstly it is able topredict the variations of in-furnace states and performanceindicators with variation of key operational parameters such ascoke rate and blast rate which were qualitatively comparablewith the practical observations of the BF process [4] Also themodel is demonstrated to be able to well predict the measuredresults of experimental-scale BF [11 43] including key per-formance indicators such as top gas temperature top gasutilization factor and productivity as well as the in-furnacestates with regards to layered CZ structure gas temperatureand reduction degree Also it can precisely describe the overallperformance indicators (top gas utilization factor top gastemperature and productivity) as well as the key in-furnacestate (the position of CZ) in an experimental-scale OBF inChina under the conditions both with and without injection ofreformed coke oven gas [42])ese results confirm the generalapplicability of the model over a wide range of operations Forthis sake themodel is not further validated andmainly focuseson its application in this work

3 Simulation Conditions

Figure 1 shows the computational domain and an enlargedarea demonstrating the representative computational cells Acommercial-scale BF with the inner volume of 5000m3 is usedas the target in this work Assuming the symmetrical dis-tribution of process variables only half the BF is considered inthe simulation for computational efficiency )e wholecomputational domain is divided into 527times129 nonuniformcontrol volumes under the Cartesian coordinates whichensures that the mesh is fine enough to precisely capture thecomplicated multiphase flow in different layers in the lumpyzone and CZ )e refining of the mesh shows that this meshsize gives mesh-independent numerical solutions Based on anumber of numerical trials the computational parametershave been carefully selected so that results can get conver-gence within reasonable time and does not suffer from theproblem of divergence )e relaxation factor of the velocityfield is set at 05 and that of pressure is set at 02 )e CFDresidual is set to be 0001 )e total iteration number is set at

15000 for the give BF conditions considering the complexityof the BF ironmaking process

)e operational conditions for the BF operated withoutHGI (base case) is listed in Table 3 Burden materials in-cluding iron ore coke and flux are charged from the furnacetop with the ore batch weight of 140 tonnes A centre-de-veloped radial burden distribution of the ore-to-coke ratiosimilar to that used by previous researchers [40 43] is adoptedin this work )e hot blast is blown into the BF at the flowrateof 7300m3min and at the temperature of 1200degC Pulverisedcoal injection (PCI) is implemented at the rate of 137 tminCorresponding to the blast conditions the compositiontemperature and flowrate of the reducing gas generated fromthe raceway are determined based on the local mass and heatbalance and used as the inlet conditions of the gas phasewhich is also listed in Table 3 )is condition is usedthroughout the simulations for BF both with and withoutHGI Note that the water content in the hot blast is negligibleunder the present condition )us the reducing gas leavingthe raceway only consists of CO andN2 In the first part of thisstudy HGI with varying CO and CO2 is used To facilitate theimplementation of top gas recycling and considering the topgas utilization factor is usually around 50 in a well-operatedBF [1 3] the CO content in the HGI is gradually increasedfrom 50 to 100 at every increment of 10 to examine theeffects of HGI composition on BF performance )e injectiontemperature is 900degC and the injection rate is 1200m3min)e injection position is set at 525m above the tuyere centrelevel in the BF )e optimum HGI composition in terms ofimproving BF performance is then determined Based on theoptimum HGI composition a parametric study with respectto the injection position rate and temperature is performedSince gas flow in the bosh zone is a major factor limiting theBF productivity and causes unstable phenomena such asflooding [1 54] HGI is only practiced in the BF dry zone(belly and shaft) with varying position )e injection positionis ranging from 525m to 2025m (from the level of tuyerecentre) and set up at every increment of 3m )e injectionrate is increased from 0m3min to 3000m3min at everyincrement of 600m3min and injection temperature is in-creased from 500degC to 1300degC at the increment of 100degC

Table 1 Governing equations of the present model

Items DescriptionMass conservation nabla middot (εiρiui) Si where Si minus 1113936kβikRlowastk

Momentum conservation

Gasnabla middot (εgρgugug) nabla middot τg minus εgnablap + ρgεgg + Fs

g

τg εgμg[nablaug + (nablaug)T] minus (23)εgμg(nabla middot ug)I

Solid nabla middot (εsρsusus) nabla middot τs minus εsnablaps + ρsεsgτs εsμs[nablaus + (nablaus)

T] minus (23)εsμs(nabla middot us)ILiquid ul 0 vl constant

Heat and species conservation

nabla middot (εiρiuiφim) minus nabla middot (εiΓinablaφim) Sϕim

If φim is Him Γi (kicpi)

Sφim δihijα(Ti minus Tj) + ηi1113936kRlowastk (minus ΔHk)

If φim is ωim Γi ρiDi Sϕim 1113936kαimkRlowastk where

φim ωgCOωgCO2ωgH2

ωgH2O

ωgN2ωsFe2O3

ωsFe3O4ωsFeOωsflux

Phase volume fraction 1113936iεi 1

State equation p 1113936i(yiMi)RTgVg

Mathematical Problems in Engineering 3

Tabl

e2

Chemical

reactio

nsandtransportc

oefficients

inthepresentm

odel

Term

sFo

rmulation

Reactio

ns

Fe 2

O3(

s)+

CO

(g

)

Fe (

s)+

CO

2(g

)[52]

Rlowast 1

12ξ o

reε o

reP

(y

CO

minusylowast C

O)

(8314T

s)

d2 ore

De g

CO

[(1

minusf0)

minus13

minus1]

+dore[

k1(1

+1

K1)

]minus1

11139661113967

FeO

(l)

+C

(s)

F

e (l)

+C

O(

g)[53]

Rlowast 2

k2(

AcV

b)α

FeO

(A

cV

b)

0468[εϕ

coke

dcoke

]

C(

s)+

CO

2(g

)2C

O(

g)[52]

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

FeO

(s)⟶

FeO

(l)

Flux

(s)⟶

Slag

(l)

[46]

Rlowast 4

lang

Timinus

Tmin

smT

max

sm

minusTmin

sm

rang1 0(

1113928ω s

mu iρ iε id

AM

smVol

cell)

Fe 2

O3(

s)+

H2(

g)

F

e (s)

+H

2O(

g)[52]

Rlowast 5

(π

middotd2 oreφ

minus1 oreN

ore

middot273

middotP(

yH

2minus

ylowast H

2)

(22

4Tsolid

))1

kf5

+(

dore2)

[(1

minusf

s)minus

13

minus1]

Ds5

+[(1

minusf

s)23

k5(1

+1

K5)

]minus1

11139661113967

C(

s)+

H2O

(g

)

CO

(g

)+

H2(

g)[52]

Rlowast 6

(πd

2 cokeφminus

1 coke

Ncoke

middot273

middotP

yH

2O224T

solid

)(1

kf6

+6

dco

kreρ c

okeE

fprime k6)

CO

(g

)+

H2O

(g

)

CO

2(g

)+

H2(

g)[53]

Rlowast 7

729

times10

11(

yC

O)12

(y

H2O

)(PT

gas)32 ε

(exp(

minus67300

RTgas)

1

+14

158

yH2P

Tgas

1113969)

minus1386

times10

10(

yC

O)(

yH2)

12 (

PT

gas)32 ε

(exp(

minus57000R

Tgas)

1+424

yC

OP

Tgas

1113969)

SiO

2(l)

+2C

Si+2C

O(

g)

SiO

2(l)

+2C

(l)

Si(

l)+2C

O(

g)[53]

Rlowast 8

k8(

AvV

B)C

SiO

2

k8

759

times10

4exp(

minus62870

RT

s)

Diffusion

Gas

[53]

Regge8

Pe g

x8and

Pe g

y20

Reglt8

Pe g

xRe

gand

Pe g

y025Re

g

Con

ductivity

Gas

[53]

kg

n

CpρD

e gn

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

Solid

[53]

ke se

(1

minusε g

)[(1

ks

+1

ke s)

+ε g

ke s]

ke s

229

times10

minus7 d

sT3 s

Liqu

id[46]

kl

00158

TlforHM

kl

057

forsla

g

Heattransfer

coeffi

cients

Gas-solid

[40]

Nu

20

+06(Pr

)0333

(Re

g)0

5

hg

s03h

e gsand

he g

s

Nu

kgd

s

hg

minussl

ab

(0203R

e033

gPr

033

+0220R

e05

gPr

04 )

kgd

s

Gas-liqu

id[46]

Eg

l418

times10

minus4 ε

gρ g

ugC

pg(ε lρ

lul)035Re

minus037

gl

middot(Sc gPr g

)0667

(T

lminus

Tg)

Solid

-liqu

id[46]

hsl

1

(1

hs

+1

hl)

hs

2

ksC

psρ s

|1113957ulminus

1113957us|π

ds

1113969

hl

(

kld

s)

2

Re

slPr

l

1113968(155

Pr

l

1113968+309

0372

minus015Pr

l

1113968)where

Resl

φ s

dsρ l

|1113957 ulminus

1113957 us|μ

landPr

l

Cp

lμlk

l


Note that the position and profile of CZ in a BF is ofmajor importance in affecting the BF performance andstability [4 40] which also largely determines the lowerfurnace state With the same CZ a BF operated underdifferent conditions could lead to similar flow and thermalconditions at the lower part of the furnace producing HMwith similar qualities [7] Since the implementation of HGIon a BF is a novel technology that could introduce muchuncertainty the positions of CZ in BF with various HGI

operations are kept similar to those in the BF operationwithout HGI to secure a comparable and stable production)is is achieved by gradually adjusting the coke rate at BFtop via a ldquotrial and errorrdquo method In this work the BFoperation without HGI is considered to be in stable oper-ation and is treated as the base case As an exampleFigures 2(a) and 2(b) respectively show the porosity dis-tributions and enlarged CZ profiles in the BF without HGIand with HGI of 100 CO both before and after coke

0 42 6

0

5

10

15

20

44 6 7 85

5

6

7

Burden materials

Blas

t cen

ter

Hot blast

HGI

CZ

Wall

Soild outlet

v = 0

дPдr = 0

дuдr = 0

дuдr= 0

(a) (b)

Figure 1 Schematic illustration of the computational domain (a) and its representative grid arrangement (b)

Table 3 Inlet conditions in the base case simulated

Variables ValuesGasInlet velocity (ms) 188Inlet gas component (molepercentage) 38925 pct CO 00 pct CO2 00 pct H2 00Pct H2O 61075 pct N2

Inlet gas temperature (degC) 20706Top pressure (atm) 20SolidOre tmiddotHM 164

Ore components (mass fraction) Fe2O3 06566 FeO 01576 CaO 00652 MgO 00243 SIO2 006 Al2O3 00295 MnO 00061 P2O50008

Average ore particle size (m) 0018Coke (kgtmiddotHM) 300Coke components (mass fraction) C 0857 Ash 0128 S 0005 H 0005 N 0005Average coke particle size (m) 0045Flux (ttmiddotHM) 00264Flux components (mass fraction) CaO 0438 MgO 0079 SiO2 0024 Al2O3 0033 CO2 in CaO 0344 CO2 in MgO 0082Ore voidage 0403(100dore)014

Coke voidage 0153logdcoke + 0742Average ore(ore + coke) volumeratio 05923

Burden temperature (degC) 25


reduction It is shown that inverse V-shaped CZs are ob-tained in all the operations which is mainly controlled by theburden distribution pattern and hence porosity distribution[55 56] However the CZ position rises significantly due to theHGI of 100CO)is suggests that there is excessive energy inthe BF with HGI of 100 CO before coke reduction As seenfrom Figure 2(b) with proper adjustment of coke rate similarCZ profiles and positions can indeed be obtained for theoperations with and without HGI )e achieved fuel rate andproductivity are calculated and shown in Figure 3 in Section41 Such a method is adopted throughout this work whenquantifying the coke rate for a given operation with HGI

4 Results and Discussion

41 Effects of HGI Composition )e effects of varying HGIcomposition are examined first by changing the CO and CO2contents shows the heating-up process in the BF withoutHGI and with HGI of different compositions To be clearonly the results for BF without HGI with HGI of 50CO+50 CO2 and HGI of 100 CO are shown In additionto the in-furnace solid temperature for the BF without HGIand with different HGI being represented by flooding thelines representing the solid temperature for the base oper-ation (BF operated without HGI) are also added to all thecases considered for comparison As seen from the figure forall the operations the solid temperature is higher in thecentre region and gradually decreases to the peripheral

region as affected by the centre developed burden distri-bution Hence the temperature profile in the furnace is notsignificantly affected by HGI but still dominated by theburden distribution patterns [55 56] Compared with the BFwithout HGI the solid temperature is higher in the upperfurnace with HGI regardless of the injection compositionwhich suggests that heat energy is supplied to the upperfurnace and HGI operations result in more severe coolinglosses of heat from the wall [57] )e simulation result is inline with the previous study [23] based on an EBF withinjection of hot reformed gas It is also found that the solidtemperature is the highest for BF with HGI of 50CO+50CO2 which should be attributed to the decreased produc-tivity and leading to a smaller thermal flow ratio in the upperfurnace [1 9 21 42]

shows the reduction degree together with the indirectreduction rate of iron ore in the BF without HGI and withHGI of different compositions As seen from the figure thereduction process is improved over the whole cross-sectionalarea for HGI of 50 CO+50 CO2 and injection of 100CO in the furnace top part )is is corresponding to theincreased upper furnace temperature that facilitates theindirect reduction rate of iron ore It can also be seen fromthe figure that eventually all the operations can successfullyfinish the smelting process of iron ore at similar longitudinallevels)ese are similar results as that observed on an EBF inLKAB [11] in which reformed coke oven gas was injectedinto the lower shaft )e EBF study showed that the

Coke layer

Ore layer

HGI

Before cokereduction

After cokereduction

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

10

5

0

0504804504035030250201501005

Porosit(-)

HGI

(I) (II) (III)

(I)(II)(III)

Lumpy zone

CZDripping zone

Deadman

(a)

(b)

Figure 2 Simulated porosity distribution (a) and CZ (b) for the BF operated without HGI (I) HGI of 100 CO before coke reduction (II)and after coke reduction (III)


reduction process is mainly accelerated above the lowerinjection level and gradually approaches that in the baseoperation below the injection level It can be seen from thefigure that the composition of injected gas has strong impacton the chemical reactions in the furnace especially theregion near the injection inlet )e indirect reduction of ironore is intensified in the operation with HGI of 100 COInterestingly it was also noted that indirect reduction of ironore was significantly delayed around the injection level and aldquohollowrdquo is formed in the operation of BF with HGI of 50CO+50 CO2 It is because the local gas composition hasalready reached the reaction equilibrium and prevents theindirect reduction from further proceeding while it is theopposite situation for the use of pure CO that has an effecton lowering down the local CO2-to-CO ratio )e results forBF with HGI of CO are in line with the simulation [31] andEBF [1 11] results in which indirect reduction is intensifiedin the region near the injection inlet However it is seen thatthe region affected by HGI is small )is is due to the in-sufficient penetration and therefore the injected gas mainlyflows in the peripheral region which is in line with the

previous studies using EBF [11] cold model [10 19] andnumerical model [20 42]

)e coke rate consumed in a BF primarily consists oftwo parts including those consumed through chemicalreactions (direct reduction of iron ore and carbon solutionloss reaction) and those combusted in front of tuyere tosupply part of the required heat for the smelting processapart from the energy supplied by fuel materialsrsquo injectionand external heat energy [1 4] Figures 6(a) to 6(c) re-spectively plot the coke rate consumed through directreduction (CRDR) carbon solution loss (CRSL) and com-bustion in front of tuyere (CRTY) against the CO content inHGI As seen from the figure the coke rate consumedthrough direct reduction decreases when the CO content inHGI is increased )is should mainly be attributed to theintensified indirect reduction of iron ore in the regionaround the injection level as stated above Consequentlyless iron ore is reduced through direct reduction by coke Itis also seen that only the BF with HGI of 50 CO+ 50CO2 leads to increased coke rate consumed by direct re-duction compared with the base operation without HGI)is is because the iron ore in the peripheral region goesthrough the ldquohollowrdquo region where indirect reduction ofiron ore is significantly deteriorated )e coke rate con-sumed through carbon solution loss also decreases as COcontent in HGI is increased )is is expected because thereducing gas atmosphere in the furnace is strengthened asmore CO is injected into the BF which inhibits the solutionloss reaction Figure 6(c) shows that the coke rate con-sumed through combustion in front of tuyere decreaseswhen the CO content in the injected gas is increased)is ismainly because that the coke-consuming reactions iedirect reduction and carbon solution loss that are stronglyendothermic are restricted while indirect reduction that ismildly exothermic is intensified when CO content in theHGI is increased [1] )us the heat requirement in thefurnace becomes smaller and less heat is required to begenerated from the combustion of carbonaceous materialsin the tuyere region

)e variations of the key performance parameters in-cluding productivity (P) PCI rate (PCR) and coke rate (CR)with CO content in HGI are calculated by the BF processmodel and shown in Figures 3(a) to 3(c) respectively As seenfrom Figure 3(a) with the increased CO content in HGI theproductivity is increased )is is because the hot blast rateand hence the heat input for a unit time is kept constant fordifferent operations considered in this work As statedabove the heat required (as indicated by carbonaceousmaterials consumed through combustion in front of tuyere)for producing unit HM decreases which means that moreiron ore can be smelted into HM and the productivity in-creases accordingly)is is in line with a number of previousstudies based on EBF [11 23] and mathematical model [31]As shown in Figure 3(b) in accordance with the change ofproductivity since the PC is injected as a constant in unittime the PCI rate (unit HM basis) is decreased when COcontent in HGI is increased As discussed above since thecoke rate consumed through direct reduction carbonsolution loss and combustion in front of tuyere all

(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305

60 70 80 90 10050CO content in injection gas ()

P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

Figure 3 Calculated productivity (P) (a) PCI rate (PCR) (b) andcoke rate (CR) (c) for the BF operated with different CO contents inHGI


decreases with the increased CO content in the HGI thecoke rate decreases consequently )is corresponds to theprevious studies by various methods such as EBF [11 23]mathematical model [31] and theoretical model [10]showing that HGI of reducing gas leads to decreased fuelrate Note that compared with the base operation all theBFs with injections show reduced coke rates except thatwith HGI of 50 CO+ 50 CO2 which indicates that theHGI with composition similar to the utilization factor ofthe top gas of a traditional BF deteriorates the BFperformance

)e simulated results show that the HGI of 100 COpresents the best BF performance in view of the significantlyincreased productivity and decreased coke and PC rate )isis in accordance with the fact that a considerable amount ofreal BFs are operated with HGI of high CO contents[18 22 25 58]

42 Parametric Study of HGI of 100 CO into BF Based onthe above results and considering that HGI of 100 CO canimprove the BF performance a systematic study with regardto the effects of HGI of 100 CO into BF is presented in thefollowing section )e key HGI parameters considered in-clude injection position temperature and rate)e effects ofthese parameters on the in-furnace states and performanceparameters have been simulated and analysed

To be succinct and convenience only representativeresults are shown for each parameter considered as theeffects of changing these parameters on in-furnace states andperformance indicators are monotonous Note that theoperation with the HGI injection rate of 0m3 is the baseoperation Figures 7(a) to 7(c) respectively show the dis-tributions of solid temperature in BFs operated with HGI ofdifferent positions rates and temperatures As seen from thefigure despite of the changing parameters the solid tem-perature gradually decreases from the centre region to theperipheral region which is dominated by the burden dis-tribution in the furnace )is is in line with the previousstudies [55 56] )e figures show that the upper furnacetemperature is increased for BF with HGI of CO regardlessof the HGI position rate and temperature )e temperaturedifferences between BF with HGI and BF without HGImainly exist in the region around and above the injectioninlet )e temperature differences between BF with andwithout HGI are larger when the injection level is higherespecially in the BF top )is is because shorter distance isprovided between the injected hot gas and burden materialswhen the injection level is higher leading to more intensifiedheat transfer in the region above the injection level Also theincreased injection gas rate leads to higher upper furnacetemperature )is is easily understood as a higher injectionrate leads to larger in-furnace gas flow rate therefore

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5

Base 50 CO+50 CO2 100 CO

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373

Solid temperature(K)

Figure 4 Simulated solid temperature distribution for the BF operated without HGI HGI of 50 CO+50 CO2 and HGI of 100 CO


strengthening the convective heat transfer in the furnace Anincreased HGI rate decreases the local temperature near theinjection inlet as the HGI temperature is lower than the localburden temperature Similarly a decreased HGI tempera-ture is seen to slightly decrease the local temperature in frontof the injection inlet within very small region Generally theeffects of varying HGI parameters on the temperature profileare small )is should be attributed to the fact that theinjected gas mainly flows in the peripheral region within anarrow region which goes through serious heat loss fromthe wall [23]

Figures 8(a) to 8(c) respectively show the distributionsof the reduction degree of iron ore together with the indirectreduction rate of iron ore in BFs operated with differentinjection positions rates and temperatures As seen fromthe figure compared with the BF operation without HGI thereduction degree is increased in BF with HGI regardless ofinjection position rate and temperature since the reducinggas atmosphere in the furnace is strengthened)e improvedindirect reduction of iron ore mainly exists in the regionnear and above the injection level )e reduction degree ofiron ore in the BF shaft is more promoted when the injection

position is lower as a longer contacting time is providedbetween injected hot gas and burdenmaterials Similarly theincreased injection gas rate also improves the indirect re-duction in the shaft as the CO concentration in the upperfurnace is increased Also it was found that a lower injectiongas temperature promotes the reduction of iron ore )is iseasily understood as the temperature at the injection posi-tion is too high that restricts the indirect reduction of ironore that is an exothermically reaction )erefore using HGIat lower temperature helps to alleviate the restriction ofindirect reduction However it should be pointed out thatsuch effect is small as the temperature profile is not muchaffected by HGI temperature

)e coke rate consumed through direct reductioncarbon solution loss and combustion in front of tuyere withCO injection at different positions rates and temperaturesare quantified and shown in Figures 9(a) to 9(c) respectivelyAs seen from Figure 9(a) compared with BF operationwithout HGI the coke rate consumed through direct re-duction is all reduced when HGI is adopted It also showsthat the amount of the reduced coke rate is larger when theinjection position is lower injection rate is larger and

25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066

indirect reduction rate(molm3lowasts)

Figure 5 Simulated indirect reduction of iron ore and reduction degree for the BF operated without HGI HGI of 50 CO+50 CO2 andHGI of 100 CO


injection temperature is lower Such results are expectedbecause a lower injection level provides a longer contactingdistance between injected gas and burden materials A largerinjection rate intensifies the reducing gas atmosphere in thefurnace )ese both facilitate the indirect reduction in theshaft and inhibit the direct reduction and are in line withtheoretical analysis [1] In the contrary an increased in-jection temperature promotes the direct reduction andsuppresses the indirect reduction as the direct reductionbeing strongly endothermic and the indirect reduction beingmildly exothermic [1 53] As seen from Figure 9(b) lowerinjection position larger injection rate and lower injectiontemperature lead to decreased amounts of coke consumed bythe solution loss reaction )is is because the solution lossreaction that being strongly endothermic is more developedin the lower furnace zone where the local temperature ishigh As the injection level becomes lower CO is injected tothe region where solution loss is stronger and has morepronounced impact on suppressing the reaction Also the

region for HGI to flow in-furnace becomes larger and in-hibits the solution loss reaction to a broader extent Anincreased HGI rate of CO decreases the concentration of thereactant (CO2) and increases the concentration of theproduct (CO) which is unfavourable for the reactionthermodynamically [1 53] Conversely the increased tem-perature of HGI facilitates the solution loss reaction in thelocal area However the effects are limited since the influ-enced area is small Figure 9(c) shows the variations of thecoke rate combusted in the tuyere zone with differentvariables of HGI As seen from the figure the amount of thecoke rate combusted in the tuyere zone decreases as theinjection position becomes lower injection rate becomeshigher and injection temperature becomes lower )eseresults are generally in accordance with the variation rates ofcoke consumed through direct reduction and solution losswhich are strongly endothermic Interestingly it was noticedthat when the injection position moves down to a certainlevel the reacted coke rate does not change much while the

(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76

1009080706050CO content in injection gas ()

BaseInjection

Figure 6 Calculated coke rates consumed through direct reduction (CRDR) (a) and solution loss (CRSL) (b) and combusted in front oftuyere (CRTY) (c) for the BF operated with different CO contents in HGI


coke rate combusted in the tuyere region still decreases )edecreased coke rate combusted in the tuyere region shouldmainly be attributed to the improved heat transfer betweenHGI and burden materials as the contact distance becomeslonger Also it was noted that although HGI with highertemperature brings in more heat energy the coke ratecombusted in the tuyere region still increases )is meansthat the heat required by the direct reduction and solutionloss outweighs that provided by the physical heat of HGIAdditionally the heat energy brought by HGI suffers from

serious heat loss and little can be transferred to the burdenmaterials

)e effects of key HGI parameters including injectionposition temperature and rate on major performanceindicators encompassing productivity PC rate and cokerate are calculated and shown in Figures 10(a) to 10(c)respectively As seen from the figure the productivity ofthe BF increases when the injection position is lowerinjection rate is larger and injection temperature islower which is in accordance with the decreased heat

25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 500 min3min 1200 min3min 2400 min3min


1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)

Figure 7 Simulated distributions of solid temperature for BF with HGI of CO at different positions (a) rates (b) and temperatures (c)


requirement by chemical reactions in the furnace (as reflectedby the carbon consumed through strong endothermic reactionsincluding direct reduction and carbon solution loss reflected inFigure 9) under the condition that the heat input in unit timesfrom raceway is kept constant Corresponding to changes ofproductivity since PC is injected as a constant in unit time thePCI rate (unit HM basis) increases as the injection positionbecomes higher injection rate becomes smaller and injectiontemperature becomes higher It can also be seen fromFigure 10(c) that the coke rate is lower when the injectionposition is lower injection rate is larger and injection

temperature is lower as a result of the summed coke rateconsumed through direct reduction carbon solution loss andcombustion in front of tuyere Generally HGI with lower in-jection position larger injection rate and lower injectiontemperature is seen to better improve the BF performance interms of increasing the productivity and decreasing the fuel rate

43 Discussion )e BF ironmaking process is concernedabout the utilization of CO in HGI and its efficiency ofreplacing the carbonaceous fuel materials (coke and PC) To

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066

Indirect reduction rate(molm3s)

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 min3min 1200 min3min 2400 min3min

141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)

Figure 8 Simulated distributions of the reduction degree for BF with HGI of CO at different positions (a) rates (b) and temperatures (c)


be comparable in this study a term named ldquoreplacementratiordquo is used to assess the efficiency of the varying key HGIparameters on replacing the carbonaceous fuel materials byCO in HGI It is defined as the ratio of the molar amount ofcarbon saved from the reduction of coke and PC to themolaramount of CO used in HGI)e effects of injection positionrate and temperature on the replacement ratio have beencalculated and are shown in Figure 11 As seen from thefigure a lower injection position leads to a higher re-placement ratio Such a result is expected as an elongatedcontacting distance gives longer reduction and heating-uptime between iron ore and injected gas It can also be seenfrom Figure 11 that optimum values of the injection rate andtemperature are found respectively at around 1200m3min

and 900degC It is explained here When the injection rate islow and insufficient reactant (CO) and heat energy isprovided to the local area the kinetics of chemical reactionsmainly indirect reduction of iron ore would not be sig-nificantly improved When the injection rate is too high thelocal iron ore is quickly reduced to a large extent and a largeportion of the injected gas would not be effectively utilisedand goes out of the BF When injection temperature is lowthe decreased local temperature suppresses indirect reduc-tion in kinetics In the contrary when injection temperatureis too high the indirect reduction that being exothermic isthermodynamically restricted which also leads to lowerreplacement ratio )ese are similar results to the previoustheoretical analysis [1] and modelling results [42] Generallyit is noted that the replacement ratio and thus the

(b)

(a)

(c)

Injection positionInjection rateInjection temperature

32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100

Injection temperature (degC)

350050

0

1000

1500

2000

2500

30000

-500

Injection rate (m3min)

6 84 12 1410 18 2016 22Injection level from tuyere centre (m)

Figure 9 Calculated coke rate consumed through direct reduction(CRDR) (a) solution loss (CRSL) (b) and combustion in front oftuyere (CRTY) (c) for BFs with HGI of CO at different positionsrates and temperatures


(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300

6 8 10 12 14 16 18 20 224Injection level from tuyere centre (m)

0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155

Figure 10 Calculated productivity (P) (a) PCI rate (PCR) (b) andcoke rate (CR) (c) for BFs with HGI of CO at different positionsrates and temperatures


utilization efficiency of HGI is mostly affected by the in-jection position compared to the other parameters

5 Conclusions

A well-developed and validated BF process model is mod-ified to study the effects of hot gas injection (HGI) of varyingparameters on BF inner states and performance indicators)e effects of injected gas composition are clarified firstAnd this is followed by a systematic study of the effects ofthe key injection variable in relation to HGI with the op-timum composition with the following findings obtained

(1) Under the current operational materials and geo-metrical conditions higher CO content in HGI leads tobetter BF performance in view of increased produc-tivity and decreased fuel rate HGI of 100 COpresents the best BF performance Compared with thebase operation without HGI the BF performance isworsened when the CO2 concentration in HGI exceeds50 in which a ldquohollowrdquo region is formed where theindirect reduction of iron ore is significantly delayed

(2) Lower injection position larger injection rate andlower injection temperature are found to befavourable conditions for HGI to be employed on theBF resulting in decreased fuel rates and increasedproductivities )ese are achieved mainly throughimproved thermochemical behaviours in the BF

(3) Under the current simulation conditions optimuminjection rate and temperature in term of the best

utilization of CO in HGI can be found)e optimumvalue was established under the kinetics and ther-modynamics restrictions )e injection position isfound to have the largest impact on the utilizationefficiency of CO in HGI

It should be pointed out that the above conclusions areobtained under the specific conditions considered)e flowsand thermochemical states of a commercial-scale BF areextremely complicated affected by many variables related tothe inner profile of furnace as well as operational and rawmaterial conditions )is study mainly demonstrated thepossible potential of implementing the HGI technology toimproving the BF performance Only the effects of the keyvariable including injection composition position rate andtemperature over a wide range are investigated In the nextstep it is necessary to conduct systematic studies to un-derstand the effects of other pertinent variables and theirinterplays to further achieve the optimum design andcontrol of BF with HGI referring to different requirementson productivity and energy consumption

Data Availability

)e DATdata used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the financial support from ChinaAssociation for Science and Technology ldquoYoung TalentSupport Projectrdquo Natural Science Foundation of JiangsuProvince (Grant no BK20180287) and Shandong ProvincialNatural Science Foundation China (Grant noZR2020ME107)

References

[1] A K Biswas Principles of Blast Furnace Ironmaking Jeoryand Practice Cootha Publishing House Brisbane Australia1981

[2] C C Xu and D Q Cang ldquoA brief overview of low CO2emission technologies for iron and steel makingrdquo Journal ofIron and Steel Research International vol 17 no 3 pp 1ndash72010

[3] Y Ujisawa K Nakano Y Matsukura K SunaharaS Komatsu and T Yamamoto ldquoSubjects for achievement ofblast furnace operation with low reducing agent raterdquo ISIJInternational vol 45 no 10 pp 1379ndash1385 2005

[4] S B Kuang Z Y Li D L Yan Y H Qi and A B YuldquoNumerical study of hot charge operation in ironmaking blastfurnacerdquo Minerals Engineering vol 63 pp 45ndash56 2014

[5] T L Guo M S Chu Z G Liu and H T Wang ldquoNumericalsimulation on blast furnace operation with hot burdenchargingrdquo Journal of Iron and Steel Research Internationalvol 21 no 8 pp 729ndash736 2014

00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0


Figure 11 Calculated replacement ratio for BFs with HGI of CO atdifferent positions rates and temperatures


[6] A Maki A Sakai N Takagaki et al ldquoHigh rate coal injectionof 218kgt at fuhuyama no 4 blast furnacerdquo ISIJ Internationalvol 36 no 6 pp 650ndash657 1996

[7] R Altland M K Beseoglu T Broch W Lanzer andK P Stricker ldquoExperience in operating blast-furnaces withhigh oil injection rates to attain high productivitiesrdquo StahlEisen vol 115 p 83 1995

[8] K S A Halim V N Andronov andM I Nasr ldquoBlast furnaceoperation with natural gas injection andminimum theoreticalflame temperaturerdquo Ironmaking amp Steelmaking vol 36 no 1pp 12ndash18 2009

[9] M Jampani J Gibson and P C Pistorius ldquoIncreased use ofnatural gas in blast furnace ironmaking mass and energybalance calculationsrdquo Metallurgical and Materials Transac-tions B vol 50 no 3 pp 1290ndash1299 2019

[10] T Yatsuzuka K Nakayama K Omori Y Hara andM Iguchi ldquoInjection of reducing gas into blast-furnace (FTGprocess)rdquo Transactions of the Iron and Steel Institute of Japanvol 13 no 2 pp 115ndash124 1973

[11] S Watakabe K Miyagawa S Matsuzaki et al ldquoOperationtrial of hydrogenous gas injection of COURSE50 project at anexperimental blast furnacerdquo ISIJ International vol 53 no 12pp 2065ndash2071 2013

[12] X Jiang J X Yu L Wang et al ldquoDistribution of reformedcoke oven gas in a shaft furnacerdquo Journal of Iron and SteelResearch International vol 27 no 12 pp 1382ndash13902020

[13] S Nomura H Terashima E Sato and M Naito ldquoSomefundamental aspects of highly reactive iron coke productionrdquoISIJ International vol 47 no 6 pp 823ndash830 2007

[14] C C Huang X J Ning G W Wang J L Zhang Z F Pengand H P Teng ldquoExperimental research on semi-coke for blastfurnace injectionrdquo Journal of Iron and Steel Research Inter-national vol 28 2020

[15] HM Ahmed N Viswanathan and B Bjorkman ldquoCompositepelletsmdasha potential raw material for iron-makingrdquo SteelResearch International vol 85 no 3 pp 293ndash306 2014

[16] A I Babich H W Gudenau K T Mavrommatis et alldquoChoice of technological regimes of a blast furnace operationwith injection of hot reducing gasesrdquo Revista de Metalurgiavol 38 no 4 pp 288ndash305 2002

[17] J van der Stel G Louwerse D Sert A Hirsch N Eklund andM Pettersson ldquoTop gas recycling blast furnace developmentsfor rsquogreenrsquo and sustainable ironmakingrdquo Ironmaking ampSteelmaking vol 40 no 7 pp 483ndash489 2013

[18] F Fink ldquoSuspension smelting reductionmdasha new method ofhot iron productionrdquo Steel Times vol 36 pp 398-3991996

[19] H Nishio and T Miyashita ldquoOn the top gas recycledreforming process and the injected gas distributionrdquo Tetsu-to-Hagane vol 59 no 12 pp 1506ndash1522 1973

[20] Y Ohno M Matsuura H Mitsufuji and T FurukawaldquoProcess characteristics of a commercial-scale oxygen blast-furnace process with shaft gas injectionrdquo ISIJ Internationalvol 32 no 7 pp 838ndash847 1992

[21] T Miyashita H Nishio T Simotsuma T Yamada andM Ohotsuki ldquoReducing gas injection into furnace stack in anexperimental furnacerdquo Tetsu-to-Hagane vol 58 no 5pp 608ndash623 1972

[22] M A Tseitlin S E Lazutkin andGM Styopin ldquoA flow-chartfor iron making on the basis of 100-percent usage of processoxygen and hot reducing gases injectionrdquo ISIJ Internationalvol 34 no 7 pp 570ndash573 1994

[23] A Decker and A Poos ldquoInjection of reformed gases intoblast-furnace stack as a means of reducing coke consump-tionrdquo Stahl Eisen vol 92 p 1077 1972

[24] M S Qin Z K Gao and Y T Zhang ldquoBlast furnace op-eration with full oxygen blastrdquo Ironmaking Steelmaing vol 15pp 287ndash292 1988

[25] W K Lu and R V Kumar ldquo)e feasibility of nitrogen-freeblast furnace operationrdquo ISS Transaction vol 5 pp 25ndash311984

[26] M Chu and J I Yagi ldquoNumerical evaluation of blast furnaceperformance under top gas recycling and lower temperatureoperationrdquo Steel Research International vol 81 no 12pp 1043ndash1050 2010

[27] P R Austin H Nogami and J I Yagi ldquoPrediction of blastfurnace performance with top gas recyclingrdquo ISIJ Interna-tional vol 38 no 3 pp 239ndash245 1998

[28] R B Smith and M J Corbett ldquoCoal-based ironmakingrdquoIronmak Steelmak vol 14 pp 49ndash75 1987

[29] S Natsui S Ueda H Nogami J Kano R Inoue andT Ariyama ldquoPenetration effect of injected gas at shaft gasinjection in blast furnace analyzed by hybrid model of DEM-CFDrdquo ISIJ International vol 51 no 9 pp 1410ndash1417 2011

[30] S Natsui S Ueda H Nogami J Kano R Inoue andT Ariyama ldquoDynamic analysis of gas and solid flows in blastfurnace with shaft gas injection by hybrid model of DEM-CFDrdquo ISIJ International vol 51 no 1 pp 51ndash58 2011

[31] M Chu H Nogami and J I Yagi ldquoNumerical analysis onblast furnace performance under operation with top gasrecycling and carbon composite agglomerates chargingrdquo ISIJInternational vol 44 no 12 pp 2159ndash2167 2004

[32] Y Ohno H Hotta M Matsuura H Mitsufuji and H SaitoldquoDevelopment of oxygen blast-furnace process with pre-heating gas injection into upper shaftrdquo Tetsu-to-Haganevol 75 no 8 pp 1278ndash1285 1989

[33] P Zhou M Yuan H Wang and T Y Chai ldquoData-drivendynamic modeling for prediction of molten iron siliconcontent using elm with self-feedbackrdquo Mathematical Prob-lems in Engineering vol 2015 p 11 Article ID 326160 2015

[34] T Ariyama S Natsui T Kon S Ueda S Kikuchi andH Nogami ldquoRecent progress on advanced blast furnacemathematical models based on discrete methodrdquo ISIJ Inter-national vol 54 no 7 pp 1457ndash1471 2014

[35] S B Kuang Z Y Li and A B Yu ldquoReview on modeling andsimulation of blast furnacerdquo Steel Research Internationalvol 89 pp 1ndash25 Article ID 1700071 2018

[36] S Ueda S Natsui H Nogami J I Yagi and T AriyamaldquoRecent progress and future perspective on mathematicalmodeling of blast furnacerdquo ISIJ International vol 50 no 7pp 914ndash923 2010

[37] J I Yagi ldquoMatehmatical modeling of the flow of 4 fluids in apacked bedrdquo ISIJ International vol 33 no 6 pp 619ndash639 1993

[38] Z Q Li K W Chu R H Pan A B Yu and J Q YangldquoComputational study of gas-solid flow in a horizontalstepped pipelinerdquo Mathematical Problems in Engineeringvol 2019 Article ID 2545347 15 pages 2019

[39] X Dong A Yu J I Yagi and P Zulli ldquoModelling of multi-phase flow in a blast furnace recent developments and futureworkrdquo ISIJ International vol 47 no 11 pp 1553ndash1570 2007

[40] X F Dong A B Yu S J Chew and P Zulli ldquoModeling ofblast furnace with layered cohesive zonerdquo Metallurgical andMaterials Transactions B vol 41 no 2 pp 330ndash349 2010

[41] S J Zhang A B Yu P Zulli B Wright and U TuzunldquoModelling of the solids flow in a blast furnacerdquo ISIJ Inter-national vol 38 no 12 pp 1311ndash1319 1998


[42] Z Li S Kuang A Yu et al ldquoNumerical investigation of noveloxygen blast furnace ironmaking processesrdquoMetallurgical andMaterials Transactions B vol 49 no 4 pp 1995ndash2010 2018

[43] Z Li S Kuang D Yan Y Qi and A Yu ldquoNumerical in-vestigation of the inner profiles of ironmaking blast furnaceseffect of throat-to-belly diameter ratiordquo Metallurgical andMaterials Transactions B vol 48 no 1 pp 602ndash618 2017

[44] K Yang S Choi J Chung and J I Yagi ldquoNumericalmodeling of reaction and flow characteristics in a blast fur-nace with consideration of layered burdenrdquo ISIJ Internationalvol 50 no 7 pp 972ndash980 2010

[45] T Inada K Takatani K Takata and T Yamamoto ldquo)e effectof the change of furnace profile with the increase in furnacevolume on operationrdquo ISIJ International vol 43 no 8pp 1143ndash1150 2003

[46] P R Austin H Nogami and J I Yagi ldquoA mathematicalmodel for blast furnace reaction analysis based on the fourfluid modelrdquo ISIJ International vol 37 no 8 pp 748ndash7551997

[47] J A de Castro A J da Silva Y Sasaki and J I Yagi ldquoA six-phases 3-D model to study simultaneous injection of highrates of pulverized coal and charcoal into the blast furnacewith oxygen enrichmentrdquo ISIJ International vol 51 no 5pp 748ndash758 2011

[48] X Yu and Y Shen ldquoComputational fluid dynamics study ofthe thermochemical behaviors in an ironmaking blast furnacewith oxygen enrichment operationrdquo Metallurgical and Ma-terials Transactions B vol 51 no 4 pp 1760ndash1772 2020

[49] X Yu and Y Shen ldquoNumerical study of the influence ofburden batch weight on blast furnace performancerdquo Metal-lurgical and Materials Transactions B vol 51 no 5pp 2079ndash2094 2020

[50] S J Chew P Zulli and A Yu ldquoModelling of liquid flow in theblast furnace )eoretical analysis of the effects of gas liquidand packing propertiesrdquo ISIJ International vol 41 no 10pp 1112ndash1121 2001

[51] P R Austin H Nogami and J I Yagi ldquoA mathematicalmodel of four phase motion and heat transfer in the blastfurnacerdquo ISIJ International vol 37 no 5 pp 458ndash467 1997

[52] I Muchi ldquoMathematical model of blast furnacerdquo Transactionsof the Iron and Steel Institute of Japan vol 7 no 5pp 223ndash237 1967

[53] ldquo)e Iron and Steel Institute of Japanrdquo Blast Furnace Phe-nomena and Modelling Elsevier Applied Science New YorkNY USA 1987

[54] X F Dong T Pham A B Yu and P Zulli ldquoFlooding diagramfor multi-phase flow in a moving bedrdquo ISIJ Internationalvol 49 no 2 pp 189ndash194 2009

[55] Z Li S Kuang S Liu et al ldquoNumerical investigation ofburden distribution in ironmaking blast furnacerdquo PowderTechnology vol 353 pp 385ndash397 2019

[56] T Inada K Takata K Takatani and T Yamamoto ldquoEffect ofblast furnace profile on inner furnace statesrdquo ISIJ Interna-tional vol 43 no 7 pp 1003ndash1010 2003

[57] T Ariyama R Murai J Ishii andM Sato ldquoReduction of CO2emissions from integrated steel works and its subjects for afuture studyrdquo ISIJ International vol 45 no 10 pp 1371ndash13782005

[58] M Qin and N F Yang ldquoA blast furnace process with pul-verized coal oxygen and gas circulation for reductionrdquoScandinavian Journal of Metallurgy vol 15 pp 138ndash1421986


examined at various levels and proved to be useful forimproving BF performance Among these technologies thehot gas injection (HGI) into the BF is considered useful dueto its possible advantages [1 16] )e hot gas can be gen-erated from the combustion and reforming of cheaper fuelmaterials and off-gas within the steelwork which is moreflexible and economical than the combustion of coke andPC It can be used to intensify the smelting of burdenmaterials and reduce the fuel rate Compared with fossil fuelinjection HGI avoids the decreased adiabatic flame tem-perature and the generation of unburnt powders In addi-tion HGI can be flexibly implemented at the BF shaft whichavoids the flow of high-speed gas in the low permeability wetzone

HGI was first introduced by Lance in the 1920s in whichit was used to partly replace the reducing gas generated fromcombustion of carbonaceous materials in the raceway [17]After that little progress wasmade until middle 1960s Usingan experimental BF (EBF) with a hearth diameter of 46mHGI of reformed gas at 1000degC was tested in Belgium [17] Inlate 1970s Fink employed this technology on an oxygen BF(OBF) to solve the thermal shortage problem [18] After thatinvestigations have been intensively performed by variousmethods such as cold model [19] experimental scale[11 20 21] and commercial scale [10 22] BFs as well astheoretical calculation [16 18 23ndash25] continuum models[10 26ndash28] and discrete models [29 30] )e EBF (innervolume 32m3) [21] and numerical model studies [27]showed that HGI should contain less CO2H2O due to thestrong endothermic effect of carbon solution loss reactionand water gas reaction )e injection position is better tolocate at the bottom of the thermal reserve zone in the BFshaft so that the reaction products (CO2H2O) would notundergo severe solution loss [1 21] Besides the temperatureof injected gas should be at around 1000degC [1 19] tomaintain the temperature profile in the BF A number ofstudies showed that HGI improves BF performance in viewof decreased coke rate and increased productivity[21ndash23 31] It was also revealed that the penetration depth ofinjected gas is in proportion to the volume ratio of injectedgas to gas generated from tuyere [1 19 29] By using an EBFit was shown that shallow penetration of HGI leads to lessimproved BF performance [11] Recently HGI is morefrequently employed on the OBF as an enabling technologyto address the thermal shortage phenomena in the upperfurnace with several typical OBF processes established[18 22 24 25 32] It is also considered as an essential partfor realizing the zero-carbon footprint OBF process throughinjection of recycled top gas after CO2 capture and storageWith those efforts HGI has been considered promising andis currently adopted by two world-class projects aiming lowcarbon production ie ULCOS in the European Union [17]and COURSE50 in Japan [11]

It is clear that the control of the operational parametersof HGI including injection composition position tem-perature and rate has significant impact on the BF per-formance However thus far a comprehensive studyregarding the effects of key operational parameters of HGIon BF inner states and overall performance indicators is yet

available )is hinders the understanding and therefore theeffective use of the technology Considering that the iron-making BF is a complicatedmultiphase reactor accompaniedwith high temperature and hazardous conditions instru-mentation is difficult to access its inner states [33] Also it isdifficult to use theoretical and experimental methods toconduct investigations comparable to a real BF situationAlternatively numerical models are playing an increasinglyimportant role in investigating the BF ironmaking processsee eg the reviews by different investigators [34ndash37]Basically the methods can be either discrete or continuum[38 39] Compared with the discrete models the contin-uum models are considered more suitable for processmodelling due to its computational efficiency )is workfor the first time presents a comprehensive numericalstudy of the effects of HGI on BF performance with respectto key performance indicators including injection com-position position temperature and rate First the BFprocess model used in this is briefly introduced )en theeffects of HGI compositions in terms of varying CO andCO2 content are performed Based on the results theoptimumHGI composition is thus identified to improve BFperformance After that a systematic study with respect tothe key HGI variables including position rate and tem-perature using the identified optimum HGI composition isconducted Detailed analysis with respect to the flow heatand mass transfer as well as thermochemical phenomena inthe BF is carried out for optimizing the injection opera-tional parameters

2 Methods

)e present mathematical model is a steady-state axisym-metric multifluid model It considers the region of a BF fromthe slag surface up to the burden surface )e phases con-sidered including gas solid and liquid Each phase in themodel is described by separate conservation equations ofmass momentum and enthalpy with the key chemicalreactions considered Gas is described by the well-estab-lished volume-averaged multiphase NavierndashStokes equa-tions [39] Solids are assumed to be the continuous phasethat can bemodelled based on the typical viscousmodel usedin multiphase flow modelling [39 40] coupled with themethod proposed by Zhang et al [41] for determination ofthe deadman boundary General convection-diffusionequations are applied to describe heat and mass transferamong the different phases)emodel is in principle similarto other BF process models developed by different investi-gators [4 40 42ndash49] and moreover it is able to model thelayered burden structure in lumpy zone and cohesive zone(CZ) [40] as well as the varying stockline [40] as well as stockline variation [4] )e details of the model and relevant nu-merical techniques are available elsewhere [4 40 41 46 50 51]and are not detailed in this paper for brevity )e governingequations key chemical reactions and transfer coefficients aresummarized in Tables 1 and 2 In this work the model ismodified so that it is able to handle BF with HGI with varyinginjection composition position rate and temperature withinwide ranges











g










ωgH2O

ωgN2ωsFe2O3





Tabl

e2

Chemical

reactio

nsandtransportc

oefficients

inthepresentm

odel

Term

sFo

rmulation

Reactio

ns

Fe 2

O3(

s)+

CO

(g

)

Fe (

s)+

CO

2(g

)[52]

Rlowast 1

12ξ o

reε o

reP

(y

CO

minusylowast C

O)

(8314T

s)

d2 ore

De g

CO

[(1

minusf0)

minus13

minus1]

+dore[

k1(1

+1

K1)

]minus1

11139661113967

FeO

(l)

+C

(s)

F

e (l)

+C

O(

g)[53]

Rlowast 2

k2(

AcV

b)α

FeO

(A

cV

b)

0468[εϕ

coke

dcoke

]

C(

s)+

CO

2(g

)2C

O(

g)[52]

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

FeO

(s)⟶

FeO

(l)

Flux

(s)⟶

Slag

(l)

[46]

Rlowast 4

lang

Timinus

Tmin

smT

max

sm

minusTmin

sm

rang1 0(

1113928ω s

mu iρ iε id

AM

smVol

cell)

Fe 2

O3(

s)+

H2(

g)

F

e (s)

+H

2O(

g)[52]

Rlowast 5

(π

middotd2 oreφ

minus1 oreN

ore

middot273

middotP(

yH

2minus

ylowast H

2)

(22

4Tsolid

))1

kf5

+(

dore2)

[(1

minusf

s)minus

13

minus1]

Ds5

+[(1

minusf

s)23

k5(1

+1

K5)

]minus1

11139661113967

C(

s)+

H2O

(g

)

CO

(g

)+

H2(

g)[52]

Rlowast 6

(πd

2 cokeφminus

1 coke

Ncoke

middot273

middotP

yH

2O224T

solid

)(1

kf6

+6

dco

kreρ c

okeE

fprime k6)

CO

(g

)+

H2O

(g

)

CO

2(g

)+

H2(

g)[53]

Rlowast 7

729

times10

11(

yC

O)12

(y

H2O

)(PT

gas)32 ε

(exp(

minus67300

RTgas)

1

+14

158

yH2P

Tgas

1113969)

minus1386

times10

10(

yC

O)(

yH2)

12 (

PT

gas)32 ε

(exp(

minus57000R

Tgas)

1+424

yC

OP

Tgas

1113969)

SiO

2(l)

+2C

Si+2C

O(

g)

SiO

2(l)

+2C

(l)

Si(

l)+2C

O(

g)[53]

Rlowast 8

k8(

AvV

B)C

SiO

2

k8

759

times10

4exp(

minus62870

RT

s)

Diffusion

Gas

[53]

Regge8

Pe g

x8and

Pe g

y20

Reglt8

Pe g

xRe

gand

Pe g

y025Re

g

Con

ductivity

Gas

[53]

kg

n

CpρD

e gn

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

Solid

[53]

ke se

(1

minusε g

)[(1

ks

+1

ke s)

+ε g

ke s]

ke s

229

times10

minus7 d

sT3 s

Liqu

id[46]

kl

00158

TlforHM

kl

057

forsla

g

Heattransfer

coeffi

cients

Gas-solid

[40]

Nu

20

+06(Pr

)0333

(Re

g)0

5

hg

s03h

e gsand

he g

s

Nu

kgd

s

hg

minussl

ab

(0203R

e033

gPr

033

+0220R

e05

gPr

04 )

kgd

s

Gas-liqu

id[46]

Eg

l418

times10

minus4 ε

gρ g

ugC

pg(ε lρ

lul)035Re

minus037

gl

middot(Sc gPr g

)0667

(T

lminus

Tg)

Solid

-liqu

id[46]

hsl

1

(1

hs

+1

hl)

hs

2

ksC

psρ s

|1113957ulminus

1113957us|π

ds

1113969

hl

(

kld

s)

2

Re

slPr

l

1113968(155

Pr

l

1113968+309

0372

minus015Pr

l

1113968)where

Resl

φ s

dsρ l

|1113957 ulminus

1113957 us|μ

landPr

l

Cp

lμlk

l




0 42 6

0

5

10

15

20

44 6 7 85

5

6

7

Burden materials

Blas

t cen

ter

Hot blast

HGI

CZ

Wall

Soild outlet

v = 0

дPдr = 0

дuдr = 0

дuдr= 0

(a) (b)















Coke layer

Ore layer

HGI


After cokereduction

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

10

5

0

0504804504035030250201501005

Porosit(-)

HGI

(I) (II) (III)

(I)(II)(III)

Lumpy zone

CZDripping zone

Deadman

(a)

(b)







(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)







25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0




































































g










ωgH2O

ωgN2ωsFe2O3





Tabl

e2

Chemical

reactio

nsandtransportc

oefficients

inthepresentm

odel

Term

sFo

rmulation

Reactio

ns

Fe 2

O3(

s)+

CO

(g

)

Fe (

s)+

CO

2(g

)[52]

Rlowast 1

12ξ o

reε o

reP

(y

CO

minusylowast C

O)

(8314T

s)

d2 ore

De g

CO

[(1

minusf0)

minus13

minus1]

+dore[

k1(1

+1

K1)

]minus1

11139661113967

FeO

(l)

+C

(s)

F

e (l)

+C

O(

g)[53]

Rlowast 2

k2(

AcV

b)α

FeO

(A

cV

b)

0468[εϕ

coke

dcoke

]

C(

s)+

CO

2(g

)2C

O(

g)[52]

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

FeO

(s)⟶

FeO

(l)

Flux

(s)⟶

Slag

(l)

[46]

Rlowast 4

lang

Timinus

Tmin

smT

max

sm

minusTmin

sm

rang1 0(

1113928ω s

mu iρ iε id

AM

smVol

cell)

Fe 2

O3(

s)+

H2(

g)

F

e (s)

+H

2O(

g)[52]

Rlowast 5

(π

middotd2 oreφ

minus1 oreN

ore

middot273

middotP(

yH

2minus

ylowast H

2)

(22

4Tsolid

))1

kf5

+(

dore2)

[(1

minusf

s)minus

13

minus1]

Ds5

+[(1

minusf

s)23

k5(1

+1

K5)

]minus1

11139661113967

C(

s)+

H2O

(g

)

CO

(g

)+

H2(

g)[52]

Rlowast 6

(πd

2 cokeφminus

1 coke

Ncoke

middot273

middotP

yH

2O224T

solid

)(1

kf6

+6

dco

kreρ c

okeE

fprime k6)

CO

(g

)+

H2O

(g

)

CO

2(g

)+

H2(

g)[53]

Rlowast 7

729

times10

11(

yC

O)12

(y

H2O

)(PT

gas)32 ε

(exp(

minus67300

RTgas)

1

+14

158

yH2P

Tgas

1113969)

minus1386

times10

10(

yC

O)(

yH2)

12 (

PT

gas)32 ε

(exp(

minus57000R

Tgas)

1+424

yC

OP

Tgas

1113969)

SiO

2(l)

+2C

Si+2C

O(

g)

SiO

2(l)

+2C

(l)

Si(

l)+2C

O(

g)[53]

Rlowast 8

k8(

AvV

B)C

SiO

2

k8

759

times10

4exp(

minus62870

RT

s)

Diffusion

Gas

[53]

Regge8

Pe g

x8and

Pe g

y20

Reglt8

Pe g

xRe

gand

Pe g

y025Re

g

Con

ductivity

Gas

[53]

kg

n

CpρD

e gn

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

Solid

[53]

ke se

(1

minusε g

)[(1

ks

+1

ke s)

+ε g

ke s]

ke s

229

times10

minus7 d

sT3 s

Liqu

id[46]

kl

00158

TlforHM

kl

057

forsla

g

Heattransfer

coeffi

cients

Gas-solid

[40]

Nu

20

+06(Pr

)0333

(Re

g)0

5

hg

s03h

e gsand

he g

s

Nu

kgd

s

hg

minussl

ab

(0203R

e033

gPr

033

+0220R

e05

gPr

04 )

kgd

s

Gas-liqu

id[46]

Eg

l418

times10

minus4 ε

gρ g

ugC

pg(ε lρ

lul)035Re

minus037

gl

middot(Sc gPr g

)0667

(T

lminus

Tg)

Solid

-liqu

id[46]

hsl

1

(1

hs

+1

hl)

hs

2

ksC

psρ s

|1113957ulminus

1113957us|π

ds

1113969

hl

(

kld

s)

2

Re

slPr

l

1113968(155

Pr

l

1113968+309

0372

minus015Pr

l

1113968)where

Resl

φ s

dsρ l

|1113957 ulminus

1113957 us|μ

landPr

l

Cp

lμlk

l




0 42 6

0

5

10

15

20

44 6 7 85

5

6

7

Burden materials

Blas

t cen

ter

Hot blast

HGI

CZ

Wall

Soild outlet

v = 0

дPдr = 0

дuдr = 0

дuдr= 0

(a) (b)















Coke layer

Ore layer

HGI


After cokereduction

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

10

5

0

0504804504035030250201501005

Porosit(-)

HGI

(I) (II) (III)

(I)(II)(III)

Lumpy zone

CZDripping zone

Deadman

(a)

(b)







(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)







25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0



























































Tabl

e2

Chemical

reactio

nsandtransportc

oefficients

inthepresentm

odel

Term

sFo

rmulation

Reactio

ns

Fe 2

O3(

s)+

CO

(g

)

Fe (

s)+

CO

2(g

)[52]

Rlowast 1

12ξ o

reε o

reP

(y

CO

minusylowast C

O)

(8314T

s)

d2 ore

De g

CO

[(1

minusf0)

minus13

minus1]

+dore[

k1(1

+1

K1)

]minus1

11139661113967

FeO

(l)

+C

(s)

F

e (l)

+C

O(

g)[53]

Rlowast 2

k2(

AcV

b)α

FeO

(A

cV

b)

0468[εϕ

coke

dcoke

]

C(

s)+

CO

2(g

)2C

O(

g)[52]

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

FeO

(s)⟶

FeO

(l)

Flux

(s)⟶

Slag

(l)

[46]

Rlowast 4

lang

Timinus

Tmin

smT

max

sm

minusTmin

sm

rang1 0(

1113928ω s

mu iρ iε id

AM

smVol

cell)

Fe 2

O3(

s)+

H2(

g)

F

e (s)

+H

2O(

g)[52]

Rlowast 5

(π

middotd2 oreφ

minus1 oreN

ore

middot273

middotP(

yH

2minus

ylowast H

2)

(22

4Tsolid

))1

kf5

+(

dore2)

[(1

minusf

s)minus

13

minus1]

Ds5

+[(1

minusf

s)23

k5(1

+1

K5)

]minus1

11139661113967

C(

s)+

H2O

(g

)

CO

(g

)+

H2(

g)[52]

Rlowast 6

(πd

2 cokeφminus

1 coke

Ncoke

middot273

middotP

yH

2O224T

solid

)(1

kf6

+6

dco

kreρ c

okeE

fprime k6)

CO

(g

)+

H2O

(g

)

CO

2(g

)+

H2(

g)[53]

Rlowast 7

729

times10

11(

yC

O)12

(y

H2O

)(PT

gas)32 ε

(exp(

minus67300

RTgas)

1

+14

158

yH2P

Tgas

1113969)

minus1386

times10

10(

yC

O)(

yH2)

12 (

PT

gas)32 ε

(exp(

minus57000R

Tgas)

1+424

yC

OP

Tgas

1113969)

SiO

2(l)

+2C

Si+2C

O(

g)

SiO

2(l)

+2C

(l)

Si(

l)+2C

O(

g)[53]

Rlowast 8

k8(

AvV

B)C

SiO

2

k8

759

times10

4exp(

minus62870

RT

s)

Diffusion

Gas

[53]

Regge8

Pe g

x8and

Pe g

y20

Reglt8

Pe g

xRe

gand

Pe g

y025Re

g

Con

ductivity

Gas

[53]

kg

n

CpρD

e gn

Rlowast 3

(6ξ

cokeε cok

epy

co2(

8314T

s)

dcokek

f+6

(ρ c

okeE

fk3)

)

Solid

[53]

ke se

(1

minusε g

)[(1

ks

+1

ke s)

+ε g

ke s]

ke s

229

times10

minus7 d

sT3 s

Liqu

id[46]

kl

00158

TlforHM

kl

057

forsla

g

Heattransfer

coeffi

cients

Gas-solid

[40]

Nu

20

+06(Pr

)0333

(Re

g)0

5

hg

s03h

e gsand

he g

s

Nu

kgd

s

hg

minussl

ab

(0203R

e033

gPr

033

+0220R

e05

gPr

04 )

kgd

s

Gas-liqu

id[46]

Eg

l418

times10

minus4 ε

gρ g

ugC

pg(ε lρ

lul)035Re

minus037

gl

middot(Sc gPr g

)0667

(T

lminus

Tg)

Solid

-liqu

id[46]

hsl

1

(1

hs

+1

hl)

hs

2

ksC

psρ s

|1113957ulminus

1113957us|π

ds

1113969

hl

(

kld

s)

2

Re

slPr

l

1113968(155

Pr

l

1113968+309

0372

minus015Pr

l

1113968)where

Resl

φ s

dsρ l

|1113957 ulminus

1113957 us|μ

landPr

l

Cp

lμlk

l




0 42 6

0

5

10

15

20

44 6 7 85

5

6

7

Burden materials

Blas

t cen

ter

Hot blast

HGI

CZ

Wall

Soild outlet

v = 0

дPдr = 0

дuдr = 0

дuдr= 0

(a) (b)















Coke layer

Ore layer

HGI


After cokereduction

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

10

5

0

0504804504035030250201501005

Porosit(-)

HGI

(I) (II) (III)

(I)(II)(III)

Lumpy zone

CZDripping zone

Deadman

(a)

(b)







(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)







25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0





























































0 42 6

0

5

10

15

20

44 6 7 85

5

6

7

Burden materials

Blas

t cen

ter

Hot blast

HGI

CZ

Wall

Soild outlet

v = 0

дPдr = 0

дuдr = 0

дuдr= 0

(a) (b)















Coke layer

Ore layer

HGI


After cokereduction

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

10

5

0

0504804504035030250201501005

Porosit(-)

HGI

(I) (II) (III)

(I)(II)(III)

Lumpy zone

CZDripping zone

Deadman

(a)

(b)







(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)







25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0
































































Coke layer

Ore layer

HGI


After cokereduction

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 80 2 4 6 8

10

5

0

0504804504035030250201501005

Porosit(-)

HGI

(I) (II) (III)

(I)(II)(III)

Lumpy zone

CZDripping zone

Deadman

(a)

(b)







(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)







25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0































































(a)

(c)

(b)

BaseInjection

220

225

230

235

240

166

168

170

172

174

176

178

280

285

290

295

300

305


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)







25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0































































25

20

15

10

5

0

-5

25

20

15

10

5

0

-5

25

20

15

10

5

0

-50 5 0 5 0 5


373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

373

593

773

873

973

1073

1273

14731673

1673

147312731073973873773593

373








25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0































































25

20

15

10

5

0

-50 2 4 6 8 0 2 4 6 8 0 2 4 6 8

25

20

15

10

5

0

-5

25

20

15

10

5

0

-5


0111

0333

099

0111 0111

0333 0333

099 099

Fe2 O3rarrFe3 O

4

Fe3 O4rarrFeO

FeOrarrFe

141499

3018161412108649750442

00614690

11336701066






(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0





























































(c)

(b)

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

(a)

180

185

190

28

29

30

31

32

3368

70

72

74

76


BaseInjection






25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0






























































25

20

15

10

5

-550 50 50

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

535 m 1135 m 1735 m


1673

147312731073963873773592

373

(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0



1673

147312731073963873773592

373

(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

50 50 50500degC 900degC 1300degC


1673

147312731073963873773592

373

(c)






25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0






























































25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8535 m 1135 m 1735 m

141499

3018161412108649750442

00614690

11336401066


(a)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0


141499

3018161412108649750442

00614690

11336401066


(b)

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

25

20

15

10

5

-5

0

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8500degC 900degC 1300degC

141499

3018161412108649750442

00614690

11336401066


(c)





(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0





























































(b)

(a)

(c)


32

60

65

70

75

80

28

30

170

175

180

185

190

195

CRDR

(kg

tmiddotHM

)CR

SL (k

gtmiddotH

M)

CRTY

(kg

tmiddotHM

)

500

600

100080

0

900

120040

0

700

1300

1400

1100


350050

0

1000

1500

2000

2500

30000

-500





(a)

(b)

(c)

22

23

24

25

160

165

170

175

180

260

270

280

290

300


0

500

1000

1500

2000

2500

3000

3500

-500


500

600

700

800

900

1000

1100

1200

1300

140040

0


P (tmiddot

HM

m3 middotd

ay)

PCR

(kg

tmiddotHM

)CR

(kg

tmiddotHM

)

155




5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0




























































5 Conclusions







Data Availability




Acknowledgments


References






00

01

02

03

04

05

06

Repl

acem

ent r

atio

(-)



500

1000

1500

2000

2500

3000

35000


500

600

700

800

900

1000

1100

1200

1300

140040

0




































































































































Documents

Computational Study of Hot Gas Injection (HGI) into an