Enhancement of Low-temperature Gasification and Reduction

© 2011 ISIJ 1308

ISIJ International, Vol. 51 (2011), No. 8, pp. 1308–1315

Enhancement of Low-temperature Gasification and Reduction by Using Iron-coke in Laboratory Scale Tests

Kenichi HIGUCHI,1) Seiji NOMURA,1) Kazuya KUNITOMO,1) Hirokazu YOKOYAMA1) and Masaaki NAITO2)

1) Environment & Process Technology Center, Nippon Steel Corporation, Futtsu, Chiba, 293-8511 Japan.E-mail: [email protected]) Resource and Process Solution Center, Nippon Steel Technoresearch Corporation, Futtsu, Chiba, 293-0011 Japan.

(Received on January 11, 2011; accepted on March 4, 2011)

Iron-coke having various amount of M.Fe were produced in laboratory scale and the influence of M.Fecontent in Iron-coke on reaction behavior under the condition simulating blast furnace has been investi-gated. Cold strength of Iron-coke products was decreased with an increase of mixing ratio of iron oremostly due to a prevention of dilatation of coal particles by iron ore, resulting in weak bonding of coal par-ticles. Nevertheless formed Iron-coke with iron ore in the fraction up to 30% would have enough strengthfor use in blast furnace as nut coke. Both CRI and JIS-reactivity were enhanced by increasing ratio ofmixed iron ore, confirming the catalysis effect of M.Fe. The temperature at which carbon consumptionstarted was lowered with an increase of T.Fe in coke. Formed Iron-coke containing 43% of T.Fe startedreaction consuming its carbon at lower temperature than conventional coke by 150°C. Furthermore, con-sumed carbon ratio was improved by M.Fe installation to coke due to increasing gasification. Processevaluation with using Iron-coke in blast furnace was performed by BIS test. It was revealed that usingformed Iron-coke having 43% of T.Fe for blast furnace resulted in an increase of shaft efficiency by 6.8%.It was found that to lower the reducing agent rate in blast furnace by decreasing the temperature of ther-mal reserve zone, lowering the beginning temperature of coke reaction was effective. Usage of Iron-cokehaving M.Fe catalyst within coke matrix is one of the methods.

KEY WORDS: ironmaking; blast furnace; reduction; coke reactivity; strength; formed coke.

1. Introduction

Reducing greenhouse gas by improving energy efficiencyis the most important issue in Industry field. As 8% of totalenergy is consumed at ironmaking process in Japan, a newtechnology reducing energy consumption of blast furnace ismost beneficial. Standing upon this background, researchprojects focusing on innovative agglomerates for blast fur-nace with high reactivity has been promoted. Those projectslead a conclusion that one of the key technologies for energysaving of blast furnace is increasing reactivity of carbon.1)

To accelerate reaction of the agglomerates, shortening dis-tance between carbon and iron oxide is essential. Suchagglomerates could be attained by composite agglomeratebetween carbon and iron oxide or Iron-coke.

Some of authors, Naito et al.2) proposed that enhancingreactivity of coke is beneficial for lowering the temperatureof thermal reserve zone in blast furnace, resulting in highefficiency of reduction. Many investigations reported cata-lyst effect of Ca or Fe on gasification of carbon.3–7) Further-more plant trials proved that Ca-rich coke containing Ca asa catalyst could decrease reducing agent rate of blast fur-nace.8)

Usage of low grade iron ores as raw materials of suchagglomerates is attractive to meet a lack of high grade ironore resources. Therefore the Iron-coke containing Fe as a

catalyst made from the mixture of coal and fine ores havebeen investigated with intensity as well.9,10) Although theexisting of limit of lowering temperature of thermal reservezone for decreasing reducing agent rate was reported,11) oneof authors, Nomura et al. found a possibility of an decreaseof reducing agent rate of blast furnace with using Iron-cokeeven under alkali-loaded conditions.12)

However, to ensure this process, desirable mixing ratio ofiron ores in terms of the whole process designing and behav-ior of Iron-coke in blast furnace is still unknown. This paperpays the attention for catalyst effect of M.Fe on gasificationof coke and provides the information on the influence ofamount of M.Fe in Iron-coke on behavior of Iron-cokeunder the condition simulating blast furnaces.

2. Experimental Procedure

2.1. Producing Iron-cokeTwo kinds of coal, coal G (caking coal) and coal N

(slightly caking coal), and iron ore were used in the presentstudy. Table 1 shows properties and chemical compositionof coals and iron ore.

Table 2 shows mixing conditions of raw materials forIron-coke production. Two producing methods were per-formed, without briquetting before coking as conventionalcoke making process and with briquetting before coking as

ISIJ International, Vol. 51 (2011), No. 8

1309 © 2011 ISIJ

formed coke process. Preparation method of coke sampleswas the same as the method in the previous investigation.12)

2.2. Reaction TestsReaction behavior involving with reduction of iron oxide

and gasification of carbon in Iron-coke has been investigat-ed with using coke reaction simulator, CRS,13) shown in Fig.1. 200 gram of Iron-coke products whose diameter rangedbetween 19 and 21 mm was set in reaction tube. Pre-heatedgas was flow through layers of Al2O3 balls. During reaction,weight change and composition of exhaust gas were mea-sured simultaneously. Tests were performed in three series

having different conditions of gas and temperature as shownin Table 3. Reaction behavior of Iron-coke products in N2

and CO+CO2 atmosphere was evaluated in CRS1 and CRS2test, respectively. In CRS3 test, Reaction behavior of Iron-coke products under the condition simulating blast furnacewas evaluated.

To estimate the process using Iron-coke in blast furnace,blast furnace inner reaction simulator, BIS, was used. BIS2)

can evaluate reaction efficiency thorough simulating reduc-tion and heat transfer phenomena in shaft of blast furnace.BIS is originated from BORIS furnace14) and modified towork under an adiabatic condition, which provides the bur-den with ‘an actual reducing condition’ determined by heattransfer and quantity of endothermic reaction by carbonsolution loss.

Agglomerates and coke are charged into the reaction tubeto form layer-by-layer structure and then electric furnace ismoved from upper to lower. Bosh gas is simultaneouslyintroduced from the upper section of the reaction tube,resulting in a countercurrent moving layer. Inlet gascondition of BIS test was set constant, i.e. equivalent to1 360 Nm3/tp bosh gas with a composition of 36.0% CO,7.0% H2 and 57.0% N2, after consideration of pulverizedcoal injection. In BIS test with using carbon - iron oxidecomposite agglomerates, reducing agent ratio was set at

Table 1. Properties of coals and chemical composition of iron ore used in the present study.

Coal

Proximate analysis(mass%)dry basis

Ultimate analysis(mass%)dry basis

Caking properties PetrographicanalysisDilatometry Gieseler plastometry

Ash VM C H N Totaldilatation (%)

Maximum fluidity(log MF/ddpm) Ro (%) TI (%)

coal G 9.0 23.8 81.71 4.75 1.82 119 2.92 1.19 28.2

coal N 9.7 36.4 76.57 5.23 1.81 43 2.22 0.73 18.1

Chemical composition of iron ore (mass%)

T.Fe FeO SiO2 CaO Al2O3 MgO TiO2 S P Mn CW Na2O K2O

67.93 0.13 1.08 0.06 0.50 0.04 0.07 0.003 0.033 0.44 0.38 0.56 1.09

Table 2. Mixing conditions of raw materials for Iron-coke production.

Test No. 1 2 3 4 5 6 7

Charge materials shape Powder Briquette

Coal G % 70.0 66.5 63.0 – – – –

Coal N % 30.0 28.5 27.0 100.0 90.0 70.0 50.0

Iron ore % 0.0 5.0 10.0 0.0 10.0 30.0 50.0

Total % 100.0 100.0 100.0 100.0 100.0 100.0 100.0

SOP % – – – 8.0 8.0 8.0 8.0

Bulkdensity(kg/m3)

Coal 850 850 850 542 534 488 387

Coal + Iron ore 850 895 944 542 593 698 774

Coal+ Iron ore +SOP – – – 585 640 754 835

Fig. 1. Schematic diagram of apparatus of CRS test.

Table 3. Test conditions of CRS.

CRS 1 CRS 2 CRS 3

Gas

N2

CO + CO2(CO/CO2=

50/50)

N2(RT–800°C)

CO + CO2(800–1 200°C)

CO/(CO+CO2) =0.6–0.95*

Flow rate 20 Nl/min (8 cm/s)

Temperature

RT–1 100°Cat 10°C/min



1100°Cfor 60 min

Sample

weight 200 g

size19–21 mm

fomed Iron-coke was crushed into four pieceswith 15–25 mm in size

* CO/(CO+CO2) = 0.000875×T(°C) – 0.1

© 2011 ISIJ 1310


481 kg/tp by decreasing coke consumption.Reduction degree and temperature at fixed sample posi-

tion were monitored during descent of electric furnace. Thewhole process evaluation involving with gas utilization ratioand shaft efficiency was performed by monitoring the com-position of exhaust gas after reaching steady state. Afterevaluation of the whole process, samples were quenched byN2 stream. Microstructures, chemical compositions ofquenched samples with different position and temperatureswere analyzed. Table 4 shows test conditions of BIS test.Equivalently half of carbon in conventional coke was placedwith Iron-coke products. Charged T.Fe was maintained con-stant by decreasing charged sinter. Iron-coke was mixedwith conventional coke layer.

3. Results and Discussion

3.1. Basic Properties of Iron-cokeFigure 2 shows appearances of formed Iron-coke prod-

ucts carbonized from briquettes. It was clear that the samplein Test 4 without addition of iron ore expanded greatly. Onthe other hand, the samples in Test 5 to Test 7 with additionof iron ore did not show a strong expansion.

Figure 3 shows changes in cold strength (I60010) of Iron-

coke products with blending ratio of iron ore. In both pro-duction methods, cold strength of Iron-coke productsdecreased with an increase of mixing ratio of iron ore. How-ever, the strength of formed Iron-coke was rather, maintain-ing above 80% of I600

10 even mixing iron ore by 30%. Thisresult indicates that formed Iron-coke with iron ore in thefraction up to 30% would have enough strength for use inblast furnace as nut coke, since required strength of nut cokeis not so high.

The major reason for the decrease of strength by addingiron ore is mostly due to a prevention of dilatation of coalparticles by iron ore, resulting in weak bonding of coal par-ticles. Figure 4 shows results of optical microstrural obser-vation of formed Iron-coke products. Weak bonding in cokematrix was observed in the sample of Test 5 with 10% addi-tion of iron ore. Moreover, it was observed in the samplesof Test 7 with 50% addition of iron ore that only coarse coalparticles expanded although fine coal particles did not.

Figures 5 and 6 show results of CRI and JIS-reactivity asa function of blending ratio of iron ore powder, respectively.CRI value was corrected based on Fixed carbon of coke.Both reactivity indices were enhanced by increasing ratio ofmixed iron ore.

Table 5 shows results of chemical analysis of Iron-cokeproducts. It was found that most of added iron ores werereduced to metal during carbonization and metallizationdegree of Iron-coke products containing high T.Fe wasapproximately 70%. Iron oxides in Iron-coke products weremostly formed by re-oxidation from metal during coolingand handling otherwise remained as residual iron ore during

Table 4. Test conditions of BIS test.

Conventional coke Formed coke

Iron-coke – No. 1 No. 2 No. 3 No. 4 No. 6 No. 7

F.C of Iron-coke % 87.8 83.0 79.2 85.7 59.9 40.8

F.C of conventional coke % 87.8 87.8 87.8 87.8 87.8 87.8

T.Fe of Iron-coke % 0.3 4.4 8.5 1.5 27.0 43.2

T.Fe of sinter % 58.1 58.1 58.1 58.1 58.1 58.1

Sinter g/ch 463.0 459.0 455.0 462.0 429.0 383.0

Conventional coke* g/ch 50.0 50.0 50.0 50.0 50.0 50.0

Iron-coke* g/ch 50.0 54.0 55.0 51.0 73.0 107.0

charged T.Fe ** g/ch 269.1 269.1 269.0 269.2 269.0 268.8

charged Oxygen g/ch 111.9 111.4 111.1 111.7 107.1 101.1

charged F.C ** g/ch 87.8 88.7 87.4 87.6 87.6 87.6

* homogeneously mixed, ** kept constant

Fig. 2. Appearances of formed Iron-coke products.

Fig. 3. Relationship between iron ore blending ratio and cokestrength index.

Fig. 4. Microstructures of formed Iron-coke products.


1311 © 2011 ISIJ

carbonization.Fixed carbon values of Iron-coke products were estimated

after consideration of re-oxidation of M.Fe, FeO to Fe2O3

during measurement of ash content. Those values were in

good accordance with calculated values based on mixingratio of coal.

3.2. Gasification of Iron-cokeFigure 7 shows relationship between T.Fe content of

coke and reaction beginning temperature. Reaction begin-ning temperature was defined as the temperature at whichcarbon consumption starts, i.e., at which CO gas was startto form as a result of direct reduction in N2 atmosphere(CRS1), and at which weight loss rate, dw/dt, exceeds0.002 min–1 as a result of gasification of carbon in CO–CO2

atmosphere (CRS2). Reaction beginning temperature waslowered with an increase of T.Fe in coke in both cases. Thereaction beginning temperature of formed Iron-coke con-taining 43% of T.Fe was lower than that of formed cokewithout iron ore addition by 150°C. The temperature atwhich direct reduction took place was lower than that atwhich gasification took place by 200°C in every cases.Figure 8 shows changes in weight loss and exhaust gascomposition with sample temperatures in CRS3 test, simu-lating blast furnace conditions. ΔCO and ΔCO2 was calcu-lated by the following equations.

ΔCO (%) = COout (%)–COin (%)................ (1)

ΔCO2 (%) = CO2 out (%)–CO2 in (%) ............. (2)

In both cases of conventional coke (No. 1 to No. 3) andformed coke (No. 4 to No. 7), total weight loss at 1 200°Cwas increased with an increase of T.Fe content of coke. Atthe temperature range between 800 and 1 000°C, CO wasdecreased and CO2 was increased, representing that reduc-tion of iron oxide in Iron-coke overcame gasification of car-bon. In contrast, at the temperature range between 1 000 and1 200°C CO was decreased and CO2 was increased, repre-senting that gasification of carbon was activated.

Reactivity of formed Iron-coke was higher if we comparereactivity of sample No. 3 and No. 5 having comparableT.Fe content. This result was in accordance with the resultsin other conditions shown in Figs. 5–7, mostly due to dif-ferences of raw mixture and forming method.

Figure 9 and Table 6 show results of chemical analysisof Iron-coke products after CRS3 test. Weight loss due to anoxygen removal from iron oxide could be estimated from

Fig. 5. Changes in corrected CRI values of Iron-coke products withblending ration of iron ore powder.

Fig. 6. Changes in JIS-Reactivity of Iron-coke products with blend-ing ration of iron ore powder.

Table 5. Results of chemical analysis of Iron-coke products.

No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 No. 7

Charge material shape Powder Briquette

Iron ore (PF) % 0 5 10 0 10 30 50

T.Fe mass% 0.3 4.4 8.5 1.5 9.1 27.0 43.2

M.Fe mass% 0.1 1.9 6.2 0.6 6.6 19.7 28.8

FeO mass% 0.1 1.2 1.2 0.4 0.9 4.3 7.8

O mass% 0.1 0.9 0.8 0.3 0.9 2.7 5.3

Reduction degree %(H) n.a 51.0 76.6 n.a 75.6 77.2 71.4

Metallization degree % n.a 43.8 72.9 n.a 73.2 73.0 66.7

Ash Wt%dry 12.2 17.9 23.6 14.6 24.8 49.1 72.5

Ash after correction* Wt%dry 12.2 17.0 20.8 14.3 21.8 40.1 59.2

VM Wt%dry 0.0 0.0 0.0 0.0 0.0 0.0 0.0

FC after correction* mass% 87.8 83.0 79.2 85.7 78.2 59.9 40.8

(Ref) calculated FC** mass% 87.8 83.4 79.0 85.7 77.2 60.0 42.9

* after consideration of oxidation during ash measurement** based on mixing condition of coals

Fig. 7. Relationship between T.Fe content of coke and reactionbeginning temperature.

© 2011 ISIJ 1312


chemical analysis; hence rest of weight loss could be treatedas carbon consumption. As Fixed carbon content beforereaction was different among Iron-coke products, consumedcarbon ratio, CCR was defined as Eq. (3),

.................. (3)

C LOSS (%) : Carbon loss directly measured (see Table 6)C BEFORE (%) : Carbon content before reaction (see Table 5)

Figure 10 shows changes in consumed carbon ratio withT.Fe content of Iron-coke products before reaction. It wasfound that consumed carbon ratio was increased with anincrease of T.Fe content of coke.

As Iron-coke products used in the present study containediron oxide, carbon consumption involved with results of

‘purely’ gasification resulting in formation of CO gas andreduction resulting in formation of CO and CO2 gas. Theamount of the latter reaction depends on reduction mecha-nism. The reduction mechanism was classified into 3 typesby consumption of carbon, as follows.

1) Direct reduction by solid carbon(FeO+C = Fe+CO, consumed C/O = 1),

2) CO gas reduction by gasification of carbon(FeO+CO = Fe+CO2, consumed C/O = 0.5),

3) CO gas reduction by bulk gas(consumed C/O = 0).

It must be considered two situations of limitations abovemechanisms. Direct reduction requires physical contactbetween carbon and iron oxide hence takes place at limitedinitial stage of reduction. Furthermore, reduction by CO inbulk gas requires gas diffusion within samples hence takesplace at limited initial stage of reduction before beginningof gasification, gas-forming reaction. Those considerationslead that major contribution of reduction is CO gas reduc-tion by gasification of carbon. Estimation results of effectivegasification to form CO gas from Iron-coke products basedon above assumption; approximately 80% of consumed car-bon was effective gasification (see weight loss due to purelygasification and high consumed C/O values in Table 6).

Figure 11 shows microstructure of Iron-coke productscontaining 43% of T.Fe before and after CRS3 test. EDSanalysis revealed that pale, light gray and dark gray particleswere metal, wustite and quartz (gangue mineral of iron ore),respectively. Before reaction, metal particles was surround-ed by wustite phase, representing that wustite was formedduring cooling or handling in air. After reaction the wustitephase was disappeared, in accord with results showing thatreduction of iron oxide took place at high temperature asshown in Table 6 and Fig. 8. Simultaneously metal particles

Fig. 8. Experimental results of high temperature reaction of Iron-coke products (CRS 3, left: conventional coke, right:formed coke).

Fig. 9. Weight loss of Iron-coke products (CRS 3).

CCRC

CLOSS

BEFORE

( )%%%

=⎛

⎝⎜

⎞

⎠⎟ ⋅100


1313 © 2011 ISIJ

were half molten and or aggregated due to carburization.

3.3. Process Estimation in Using Iron-coke by BIS TestFigure 12 shows results of BIS tests. The temperature of

thermal reserve zone was lowered in both cases of usingconventional Iron-coke and using formed Iron-coke. Reduc-tion was retarded due to lowering temperature until the ther-mal reserve zone, however, accelerated at high temperaturesafter thermal reserve zone. If we see relationship betweenreduction degree of sinter and temperatures, reductiondegree of sinter was increased with an increase of T.Fe con-tent of mixed Iron-coke products.

Figure 13 shows results of process evaluation with usingIron-coke in blast furnace. As charged oxygen to be reducedwas varied in this test condition because Iron-coke productscontained M.Fe., evaluation in hematite base in terms of gasutilization ratio (CO2/(CO+CO2)×100, ηCO) of top gas andshaft efficiency was performed. The temperature was low-

Table 6. Analysis result of Iron-coke after CRS3 test.

No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 No. 7 Note

Conventional coke Formed coke

After reaction

T.Fe mass% 0.3 4.7 9.5 0.9 9.8 30.0 54.2 measuredM.Fe mass% 0.1 4.5 9.2 0.7 9.4 29.3 53.5 measuredFeO mass% 0.2 0.2 0.1 0.1 0.1 0.2 0.1 measured

Ash Wt%dry 12.3 18.4 24.7 13.7 26.1 54.0 87.5 measuredF.C after correction* mass% 87.0 83.5 79.3 86.2 77.7 58.6 35.5 = 100–VM-Ash’

Reduction degree %H** n.a 96.2 97.0 n.a 96.0 97.9 98.7

Metallization degree % n.a 95.1 96.6 n.a 95.6 97.8 98.7Weight loss (total) mass% 2.7 3.0 4.1 2.6 6.0 9.4 13.6 measured AWeight loss (reduced oxygen) mass% 0.0 0.9 0.7 0.2 0.8 2.4 5.1 measured O

Weight loss (consumed carbon) mass% 2.7 2.2 3.4 2.4 5.2 7.0 8.5 CLOSS = A–Oby gasification mass% 2.7 1.8 3.1 2.3 4.9 6.1 6.6 = C–O/16/2*12

Consumed carbon ratio % 3.0 2.6 4.3 2.8 6.6 11.6 20.9 equation (3)

Total consumed C/O molar ratio – – 6.1 – – 3.8 2.2 = C/O (in mole)

* after consideration of oxidation during ash measurement, ** hematite base, n.a : not analyzed

Fig. 10. An increase in consumed carbon ratio with increasing T.Fecontent of coke (CRS 3).

Fig. 11. Microstructures of Iron-coke with 43% of T.Fe before and after CRS test (CRS 3). M : Metal, W : Wustite, C :Coke matrix, R : Resin.

© 2011 ISIJ 1314


ered and gas utilization ratio was improved with an increaseof T.Fe content of Iron-coke products. If we compared withresult with using formed Iron-coke products having 43% ofT.Fe before reaction (No. 7) and that with using convention-al coke without addition of iron ore (No. 1), the temperatureof thermal reserve zone was lowered by 186°C and shaft

efficiency was improved by 6.8%.Figure 14 shows relationship between observed temper-

ature of thermal reserve zone in BIS test and observed reac-tion beginning temperature in CRS2 test.

Despite different measurement conditions, both resultsshowed good correlation, representing that the temperature ofthermal reserve zone closely depends on reactivity of coke.

4. Conclusions

Iron-coke products having various amount of M.Fe wereproduced in laboratory scale and the influence of M.Fe con-tent in Iron-coke on reaction behavior under the conditionsimulating blast furnace has been investigated, with payingthe attention on catalyst effect of M.Fe to enhance reactivityof coke. Following conclusions were derived.

1) Cold strength of Iron-coke products was decreased

Fig. 12. Results of BIS test with using Iron-coke products (left: conventional coke, right: formed coke, upper: temperatureand reduction degree, lower: reduction degree of ‘sinter’ calculated from chemical composition analysis).

Fig. 13. Results of BIS test.

Fig. 14. Relationship between temperature of thermal reserve zonein BIS test and the temperature at which gasification tookplace in CRS2 test.


1315 © 2011 ISIJ

with an increase of mixing ratio of iron ore mostly due to aprevention of dilatation of coal particles by iron ore, result-ing in weak bonding of coal particles. Nevertheless formedIron-coke with iron ore in the fraction up to 30% wouldhave enough strength for use in blast furnace as nut coke.Both CRI and JIS-reactivity were enhanced by increasingratio of mixed iron ore, confirming the catalysis effect ofM.Fe. Chemical analysis and microscopic observationsrevealed that most of added iron ores were reduced to metalduring carbonization.

2) The temperature at which carbon consumption start-ed was lowered with an increase of T.Fe in coke both in N2

atmospheric condition and CO–CO2 condition. FormedIron-coke containing 43% of T.Fe started reaction consum-ing its carbon at lower temperature than conventional cokeby 150°C. Furthermore, consumed carbon ratio wasimproved by M.Fe installation to coke due to increasing gas-ification.

3) Process evaluation with using Iron-coke in blast fur-nace was performed by BIS test. It was revealed that usingformed Iron-coke having 43% of T.Fe for blast furnacecould lower the temperature of thermal reserve zone by186°C, resulting in an increase of shaft efficiency by 6.8%.

4) It was found that to lower the reducing agent rate inblast furnace by decreasing the temperature of thermalreserve zone, lowering the beginning temperature of cokereaction was effective. Usage of Iron-coke having M.Fe cat-alyst within coke matrix is one of the methods.

AcknowledgementThis study was carried as a part of the research activities

“Fundamental Studies on Next Innovative Iron MakingProcess” programmed for the project “Strategic Developmentof Energy Conservation Technology Project”. The financialsupport from New Energy and Industrial TechnologyDevelopment Organization (NEDO) is gratefully acknowl-edged.

REFERENCES

1) M. Naito, S. Nomura and K. Kato: Tetsu-to-Hagané, 96 (2010), 201.2) M. Naito, M. Nakano and S. Nomura: Proc. of 3rd ICSTI, VDEh,

Düsseldorf, (2003), 539.3) A. Tomita, T. Takarada and Y. Tamai: Fuel, 62 (1983), 62.4) Y. Ohtsuka, Y. Kuroda, Y. Tamai and A. Tomita: Fuel, 65 (1986),

1476.5) Y. Kashiwaya, S. Nakaya and K. Ishii: Tetsu-to-Hagané, 77 (1991),

759.6) H. Ohme and T. Suzuki: Energy & Fuels, 10 (1996), 980.7) M. Grigore, R. Sakurovs, D. French and V. Sahajwalla: ISIJ Int., 46

(2006), 503.8) S. Nomura, H. Ayukawa, H. Kitaguchi, T. Tahara, S. Matsuzaki, M.

Naito, S. Koizumi, Y. Ogata, T. Nakayama and T. Abe: ISIJ Int., 45(2005), 316.

9) S. Nomura, H. Terashima, E. Sato and M. Naito: ISIJ Int., 47 (2007),823.

10) H. Sumi, T. Yamamoto, H. Fujimoto, T. Sato, T. Anyashiki, H. Sato,M. Sato and K. Takeda: Proc. of 5th ICSTI, CSM, Beijing, (2009),372.

11) A. Babich, D. Senk and H. W. Gudenau: Ironmaking Steelmaking,36 (2009), 222.

12) S. Nomura, K. Higuchi, K. Kunitomo and M. Naito: ISIJ Int., 50(2010), 1388.

13) H. Yokoyama and K. Kunitomo: CAMP-ISIJ, 18 (2005), 978.14) B. Bonnivard and A. Rist: Rev. Métall., 59 (1962), 401.

Documents

Enhancement of Low-temperature Gasification and Reduction