DRI Basics

Direct Reduction Fundamental and Applications - Short Course*

AISTech 2007M 6 2007May 6, 2007

Westin Indianapolis Hotel Indianapolis, Ind., USA

Direct Reduction Systems and Products

Roy WhippWhipp Technology Inc.

Adaptation of Short Course by Roy WhippAdaptation of Short Course by Roy Whipp

DefinitionsDefinitions

Why Direct Reduction?n Allows steelmaking to dilute metallic residuals inscrapHas a constant compositionn Has a constant composition

n Charging with scrap in buckets will increase thedensity and can reduce buckets charged

n Provides BF steelmaking processes with lower CO2emission

n Allows production capacity increase in blast furnacesn Allows production capacity increase in blast furnaces

What Is Direct Reduction?Direct reduction is the removal of oxygen from iron ore without

melting. Direct reduced iron (DRI) is a high quality iron product that is produced in pellet and lump forms and is generally used p p p g yat an adjacent steelmaking facility.

Source: Midrex Technologies

Iron in Nature

n IronMost important metal. It ranks fourth in abundance next tooxygen, silicon and aluminum. The average composition of theearth contains 4.15% iron.

n OxidesCommon oxides of iron found in the natural state are Fe2O3 andFe3O4.

n ImpuritiespCommon impurities found in iron oxides are the ganguecomponents SiO2 and Al2O3, sulfur, phosphorus, and bound andfree water.

Compounds of Iron

n Fe2O3 - Hematiten Fe3O4 - Magnetiten FeO - Wustite (really Fe0.95O)n Fe - Metallic iron or ironn Fe2O3-H2O - Geothiten Fe2O3 H2O Geothiten FeCO3 - Sideriten FeS2 - Pyrite

Types Of Processes

Gas-Based Processes

FeedstockFeedstockPreparationPreparation

Fines &Fines &Pellets/LumpsPellets/LumpsIron OreIron Ore

Process GasProcess Gas

ppNaturalNatural

GasGas ProcessProcessGasGas

pp

PreparationPreparationReduction UnitReduction Unit

Cold/HotCold/HotHotHot

CoalCoal

DischargeDischargeBriquettingBriquetting

HBIHBI DRIDRIHBIHBI DRIDRI

Direct Reduction Reactions

n With H23 Fe2O3 + H2 = 2 Fe3O4 + H2OFe3O4 + H2 = 3 FeO + H2OFeO + H2 = Fe + H2O

n With COn With CO3 Fe2O3 + CO = 2 Fe3O4 + CO2Fe3O4 + CO = 3 FeO + CO2F O CO F COFeO + CO = Fe + CO2

n With Solid Carbon in ReactionCO2 + C = 2CO

Categories of Oxide Feed

n GranularFeed in the form of pellets produced in a pelletizing plant from orep p p g pfines, or as naturally occurring lump iron ore. Usually > 6-8 mm insize.

n FinesIron ore fines generally under 6 mm in size although may be under12 mm. These may be naturally occurring or may have beenconcentrated in order to improve the qualityconcentrated in order to improve the quality.

General Process Feed Materials

Feed Gas SolidFines CIRCORED (FB)

FINMET (FB)FASTMET (RG)

Granular HYL (SF)MIDREX (SF)

DRC (Kiln)SL/RN (Kiln)

FB = Fluid BedFB = Fluid BedSF = Shaft FurnaceRG = Rotary Grate

Categories of Reductants n Gas

Natural gas or other gaseous stream that can be reformed orcracked to produce H or CO to be used in the reduction of thecracked to produce H2 or CO to be used in the reduction of theoxide. High methane containing natural gas is the mostcommon form. Gas may be a byproduct of other processes.

n SolidCarbon containing solid reductant such as coal, petro-coke orchar. Usually has to be smaller than lump size to facilitatec a Usua y as to be s a e t a u p s e to ac tatereaction with oxide. In rotary hearth processes it has to befinely ground to allow it to be mixed with the ore to makepellets.

Categories of Reactors

n Shaft FurnaceVertical cylindrical vessels containing internal refractory insulation.The granular oxide feed flows down by gravity and is contacted byupflowing reducing gas.

Fl id B dn Fluid BedCylindrical, generally vertical, vessels which are internallyinsulated. Iron oxide fines are either maintained in fluidizedsuspension or are carried out of the reactor by the reducing gassuspension or are carried out of the reactor by the reducing gasand recirculated (CFB).

Categories of Reactors

n Rotary KilnInclined rotating cylindrical vessels containing internal refractoryi l ti Th l id fl l th kil id d b thinsulation. The granular oxide flows along the kiln aided by theuse of lifters, and is contacted by reducing gas from a solidreductant.

n Rotary HearthA round flat hearth which rotates in the horizontal plane. Pelletsmade of oxide fines mixed with solid reductant are charged andmade of oxide fines mixed with solid reductant are charged andheated, which results in the reduction of the oxide.

Major Process Characteristics

Direct Reduction Processes

n CIRCOREDn DRCn FINMETn HYLn MIDREXn SL/RN

CIRCORED Process

Fines 2 to 0.1 mmReformed nat gas

n Feedn Reductant g

Fluid beds (2)4 bar630 C

n Reactor Typen Pressuren Temperature

HBI Merchant0.500 Mt/y

n Productn Usen Unit capacity

CIRCORED Process Flow Sheet

CIRCORED Plant - Trinidad

DRC Process

Pellets or lump oreCoal

n Feedn Reductant C

Rotary Kiln0 bar1000 C


DRICaptive0.125 Mt/y


DRC Process Flow Sheet

DRC Plant South Africa

FINMET Process

Fines 10 to 0.01 mmReformed nat gas

n Feedn Reductant Reformed nat gas

Fluid beds (4)12 bar450-800 C


HBI Merchant2.2 Mt/y

n Productn Usen Unit capacity (4 trains)

FINMET Process Flow Sheet

FINMET Plant - Venezuela

FINEX Process

Fine Ore Non-coking Coal

R4Coal

BriquettingHot DRI

Compaction

CO2Removal

Power Plant

R3

R2

R1

ReactorsCBQ

HCI

Fluidized BedReduction

MelterG ifi

Oxygen PlantProcess

Optimization

Gasifier

FINEX Plant S. Korea

HYL Process

Pellets or lump oreReformed natural gas

n Feedn Reductant g

Shaft furnace5-6 bar800-850 C Normal


DRI or HBI Merchant or captive28 through 2008 startup0 2 t 2 0 Mt/

n Productn Usen Plants (MIDREX Data)

U it it 0.2 to 2.0 Mt/yn Unit capacity

HYL Process Flow Sheet

H2OCO2

Iron Ore

Reducing gas sourcesReducing gas sources Natural GasNatural Gas Reformed GasReformed Gas Coal GasificationCoal Gasification COGCOG thth O l f ld

fuelO2

othersothers Only for cold DRI

DRIDRI

EAF

HYTEMPHYTEMP IronIron

Optional DR products:Optional DR products:

HBIHBI

HYL ZR Process Flow Sheet

Partial Oxidation andReforming Reactions

2H2 + O2 > 2H2OH O

Iron Ore

Top GasScrubber

H O

Iron Ore

Top GasScrubber

2 2 22CH4 + O2 > 2CO + 4H2

CH4 + H2O > CO + 3H2OCO + H2O > CO2 + H2

CO2Removal

H2OProcess GasCompressor HYL

ReactorGas

HeaterCO2Removal

H2OProcess GasCompressor HYL

ReactorGas

Heater

Reduction andCarburization Reactions

Fe2O3 + 3H2 > 2Fe + 3H2OFe2O3 + 3CO > 2Fe + 3CO2

3Fe + CH4 > Fe3C + 2H2

Removal unit

HumidifierOxygen

Removal unit

HumidifierOxygen

Fuel NGNGOxygen

Fuel NGNGOxygen

DRIDRI

HYL Plant - Venezuela

HYL HYTEMP SystemIron OreIron Ore

HYTEMPHYTEMP SystemSystem

H2OCO2

Reducing gases -Possible sources Natural GasNatural GasReformed GasReformed Gas

Reactor

Hot Hot DRIDRI

Transport Gas Make

up

fuel

O2Syngas (coal)Syngas (coal)COGCOG othersothers

up

ExternalCooler

EAF

Cold Cold DRIDRI

HYL HYTEMP In Plant

4M DR Plant

EAF No.1

EAFNo. 2

83 m

m

m

72 m 22

m

5

3

m

10 m

MIDREX Process

Pellets or lump oreReformed nat gas

n Feedn Reductant g

Shaft furnace1 - 1.5 bar800-850 C


DRI or HBI Merchant or captive0.3 to 2.0 M t/y


MIDREX Process Flow Sheet

MIDREX Plant Venezuela

MIDREX Process with HOTLINK

SL/RN Process

Pellets or lump oreCoal - size variable

n Feedn Reductant C

Rotary kiln0 bar1000 C


DRI Captive0.1 Mt/y


SL/RN Process Flow Sheet

SL/RN Plant

Documents

DRI Basics