Investigations on reduction of ilmenite ore with different sources of carbon M. Tripathy 1 , S. Ranganathan* 1 and S. P. Mehrotra 1,2 It is crucial to understand the relative impact of different reductants on ilmenite ore from the same source, since different reductants may have different levels of impact on the reduction of the ore. Such a study will throw light on the nature and mechanism of reduction and help in devising suitable industrial processes for the production of TiO 2 and titanium metal. Reduction of ilmenite with graphite and coke has been investigated in the temperature range 1273–1423 K. Iron was the only phase produced in the ore after reduction at 1173 K, when coke was used as the reducing agent. Significant reduction occurred at 1273 K and above. At 1273 K, Fe 3 C and rutile were formed by reduction. At higher temperatures, lower oxides of titanium were also formed by reduction. The process was controlled by diffusion at 1373 K and by reaction at the phase boundary at 1423 K, when coke was used as the reducing agent. The reduction process was controlled by nucleation at 1373 K and by reaction at the phase boundary at 1423 K, when graphite was used as the reducing agent. The rate of reduction decreased at 1423 K compared to that at 1373 K in the case of both reductants. Graphite was less effective as a reducing agent at 1273 K but more effective compared to coke at 1423 K. Whereas reduction of TiO 2 to lower oxides occurred at shorter time intervals when graphite was used as the reductant, this reaction occurred only after longer reduction periods when coke was used for reduction. Keywords: Ilmenite ore, Reduction, Graphite, Coke, Mechanism Introduction Considerable efforts are being made in many labora- tories of the world (Burlington, 2002) to develop a viable process for the production of titanium. The impetus for these efforts arises out of the fact that titanium is expected to be used extensively in the automobile in- dustry in the near future, due to its high strength/weight ratio and excellent mechanical properties (Froes et al., 2004). The high cost of production of titanium at present has severely limited its utilisation in the automobile industry. Ilmenite is a major source of titanium. Re- duction of ilmenite is an essential step in the processing of this ore to produce titanium or pigment grade rutile. Carbon is the preferred reducing agent due to its availability and low cost. The reduction of ilmenite with carbon and the kinetics of this process are influenced by the nature of the ore, that of the reducing agent, particle size and temperature. The ores vary in chemistry and mineralogy depending on the source. Understanding the nature of the carbothermic reduction of the ores is crucial for the exploitation of these ores technologically. There is little information in published literature on a comparative study of the influence of different reducing agents on the same ore, though different reductants can be relatively more effective under different conditions. Investigations were carried out to examine the reduction of an ilmenite ore with different carbonaceous reducing agents. The results of the study are discussed in this communication. Reduction of ilmenite Wang and Yuan (2006) studied the reduction of an ilmenite ore with graphite. The ore mixed with stoichio- metric amount of graphite, to convert all the oxygen in the ore to carbon monoxide, was pelletised. The pellets were heated to different temperatures for the desired periods of time and quenched. The degree of reduction, estimated from the change in the mass of the pellets, increased with the increase in temperature. The reduction of titanium oxide commenced before the reduction of iron was complete. The degree of reduction was ,40% at 1023–1273 K. Reduction was significant above 1273 K. Examination of XRD showed the presence of iron, ilmenite, rutile and reduced rutile in the reduced samples. Ilmenite disappeared above 1473 K. Pseudobrookite and a Ti 3 O 5 phase appeared above this temperature. At 1473– 1573 K, a large number of iron particles were formed and they were fine in size. At 1673 K, the rate of reduction was so high that adequate time was not available for the 1 National Metallurgical Laboratory, Council of Scientific and Industrial Research, Jamshedpur 831 007, India 2 Department of Materials and Metallurgical Engineering, Indian Institute of Technology, Kanpur208016, India *Corresponding author, email ranganathan.metals@gmail.com ß 2012 Institute of Materials, Minerals and Mining and The AusIMM Published by Maney on behalf of the Institute and The AusIMM Received 20 January 2012; accepted 21 March 2012 DOI 10.1179/1743285512Y.0000000007 Mineral Processing and Extractive Metallurgy (Trans. Inst. Min Metall. C) 2012 VOL 121 NO 3 147