Morphology and reduction kinetics of fluxed iron ore pellets

Prakash, Satya; Goswami, M C; Mahapatra, Anindita; Ghosh, Kaushik; Das, Samar K.; Sinha, Arvind; Mishra, K K

doi:10.1179/030192300677480

Cited by 19 publications

(16 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, Prakash et al 29) criticize the validity of standard tests and state that there is a danger that iron ore behaviour may be optimized under test conditions relative to actually prevailing process conditions. Wright 7) concludes that because the pellets are subjected to a continuously increasing temperature environment in a blast furnace and swelling characteristics of most pellets are temperature dependent, the applicability of results obtained from isothermal experiments is limited.…”

Section: Introductionmentioning

confidence: 99%

“…28,31) Pellet swelling has been studied extensively by thermogravimetric analysis with measuring dimensions before and after reduction under isothermal conditions. 6,9,10,14,19,22,25,27,29) Additinally, optical methods 10,[17][18][19][20] have been used. Taniguchi and Ohmi 19) have made a comparison study of methods of swelling measurement and stated that the photographic method is quite reasonable as far as the specimen shape has little change throughout the reduction.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic and Isothermal Reduction Swelling Behaviour of Olivine and Acid Iron Ore Pellets under Simulated Blast Furnace Shaft Conditions

Iljana

Mattila²,

Alatarvas

et al. 2012

ISIJ Int.

View full text Add to dashboard Cite

Pellet swelling has been widely studied, being simultaneous with reduction reactions and common in the operation of blast furnaces. A tube furnace equipped with a camera recording system was used here to study the dynamic and isothermal reduction swelling behaviour of olivine and acid pellets under simulated BF shaft conditions. The olivine pellets were magnetically separated into three fractions, containing low, medium and high amounts of magnetite in the core. The divalent iron (FeO) content of these fractions was 0.1 wt-%, 0.2 wt-% and 2.9 wt-%, respectively. Pellets with a large magnetite nucleus were observed to encompass numerous cracks, which was reflected in a poor LTD test value, while SiO2-rich reference pellets with a different slag chemistry had more restrained swelling and cracking behaviour in dynamic reduction. Swelling in the olivine pellets was associated with cracking at the boundary between the original magnetite nucleus and the hematite shell.The dynamic reduction swelling test results showed lower reduction swelling indices (max 17% in volume) than under isothermal conditions (max 51% in volume), in which case the pellets were suddenly exposed to a strongly reducing atmosphere. It is thus suggested that the reduction swelling behaviour of iron ore pellets should preferably be studied dynamically under simulated blast furnace conditions in order to achieve a realistic understanding of their swelling behaviour in a blast furnace.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dynamic and Isothermal Reduction Swelling Behaviour of Olivine and Acid Iron Ore Pellets under Simulated Blast Furnace Shaft Conditions

Iljana

Mattila²,

Alatarvas

et al. 2012

ISIJ Int.

View full text Add to dashboard Cite

show abstract

“…Kaushik and Fruehan [23,24] also demonstrated that oxidation of direct reduced iron (DRI) is also controlled by pore diffusion at the later stage of reaction. Prakash et al [37] also indicated that overall reduction of fluxed iron-ore pellets in a packed bed under gaseous atmosphere is controlled by mass transport of reducing gas through the pores.…”

Section: A Experimental Resultsmentioning

confidence: 97%

“…Another way of improving the kinetics of packed-bed reduction of composite pellets is possibly by fluxing the pellets. Prakash et al [37] showed that the kinetics and extent of reduction of fluxed ore-coal composite pellets in a packed bed increased with an increase in the basicity of the pellets. In fact, their reported values of the degree of reduction in the temperature range 800°C to 1100°C, are about 80 pct, in contrast to our data using nonfluxed pellets under inert atmosphere, which are around 65 pct.…”

Section: A Experimental Resultsmentioning

confidence: 98%

“…Relatively few studies have been reported on the reduction of iron ore-coal/ graphite composite pellets in a multilayered packed-bed reactor. [36,37] In the present study, the reduction kinetics of iron ore-graphite composite pellets in a packed-bed under reactive atmospheres have been investigated and compared with those under an inert argon atmosphere. Also, a mathematical model is developed to predict the evolution of various iron-oxide phases and metallic iron with time.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reduction Kinetics of Iron Ore-Graphite Composite Pellets in a Packed-Bed Reactor under Inert and Reactive Atmospheres

Chowdhury¹,

Roy

2008

Metall Mater Trans B

View full text Add to dashboard Cite

The rate of reduction of iron ore-graphite composite pellets in a packed-bed reactor under controlled atmosphere (inert and reducing) has been studied through experiments and modeling exercises. A customized high-mass, high-temperature thermogravimetric setup was constructed to carry out reduction experiments in a packed-bed reactor. A very low overall apparent activation energy estimated from experimental data indicates that the packed-bed reduction is unlikely to be chemical kinetics controlled. A kinetic model has been developed to calculate the temporal evolution of various phases of iron oxides and metallic iron. The rate-dependent parameters of the kinetic model are estimated from experimental data by applying an optimization tool. The predicted phases at various degrees of reduction were verified by X-ray diffraction and metallographic investigation, and a reasonable agreement between the results has been observed. It is observed that both the rate and the extent of metallic-iron production increase under reactive atmosphere. In addition, a simplified thermal model has been developed to ascertain the role of heat transfer on the kinetics of the reduction process under inert atmosphere. The reduction kinetics of the packed bed under reactive atmosphere, on the other hand, is not controlled by heat transfer and might possibly be controlled by CO-gas mass transfer through the pellets.

show abstract

Steel for a billion people: a brief appraisal of Indian steel research

Chakraborti

2001

Steel Research

View full text Add to dashboard Cite

A compact overview of the iron and steel industry in India is presented along with the current status of research and development activity. Stahl fiir 1 MilliardeMenschen: ein kurzer AbriB iiber die Stahlforschung in Indien. Dieser Ubersichtsbeitrag gibt einen kompakten Uberblick Ober die Eisen-und Stahlindustrie in Indien. Gleichzeitig vermittelt er ein Bild der gegenwartigen Aktivitaten im Bereich Forschung und Entwicklung. For informationonm publishing, Cl visit our websl http://wv.Jrw

show abstract

Morphology and reduction kinetics of fluxed iron ore pellets

Cited by 19 publications

References 6 publications

Dynamic and Isothermal Reduction Swelling Behaviour of Olivine and Acid Iron Ore Pellets under Simulated Blast Furnace Shaft Conditions

Dynamic and Isothermal Reduction Swelling Behaviour of Olivine and Acid Iron Ore Pellets under Simulated Blast Furnace Shaft Conditions

Reduction Kinetics of Iron Ore-Graphite Composite Pellets in a Packed-Bed Reactor under Inert and Reactive Atmospheres

Steel for a billion people: a brief appraisal of Indian steel research

Contact Info

Product

Resources

About