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2011-Sustainable Industrial Processing Summit
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| Editors: | Florian K |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2012 |
| Pages: | 828 pages |
| ISBN: | 978-0-9879917-0-6 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Reductant Reactivity For Chromite Reduction
Rauf Hurman Eric1; Amit Bahalla1;1UNIVERSITY OF THE WITWATERSRAND, Johannesburg, South Africa;
Type of Paper: Regular
Id Paper: 297
Topic: 4
Abstract:
A variety of carbonaceous reductants are being used in the production of ferrochromium. Matching the correct carbon reductant for each specific process and product requirements has become a vitally important function in the ferrochromium industry. In numerous cases the substitution of a reductant with a new one despite being similar in all relevant chemical specification characteristics to previous material has resulted in different performances. In this study the reducibility of chromite and reactivity of carbonaceous reductants has been simultaneously studied experimentally using the thermo gravimetric analysis (TGA) technique. The chromite ore was reduced by graphite, coal, charcoal and coke in the temperature range 1000oC to 1300oC under an inert argon atmosphere. Particle size range was +50-100, +100-150 and +150-200 microns. The results clearly indicated the temperature and particle size dependence of the reduction process. The experimental data was then fitted into the Arrhenius model to be able to obtain the indication of the reactivity of the reductant through the calculated activation energies. A generalized rate model was also used to describe the reduction of chromite which has shown that at a given particle size the rate of reduction was initially controlled mainly by interfacial area chemical reaction later switching to diffusional control.