Development of New Rutile Extraction Process and Titanium Resources

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The oxidation by the fluidized bed reactor and the acid leaching experiments were conducted using the natural ilmenite ores from Australia and Mozambique to know the most suitable condition for the newly developed rutile extraction process. The results are summarized as follows:(1) From the analyses by XRD and EPMA of the sample before and after oxidation, it was found that ilmenite (FeTiO_3) was oxidized by fluidized bed reactor to form the two phases of pseudobrookite (Fe_2TiO_5) and rutile (TiO_2). The oxidation reaction of 2FeTiO_3(s)+1/2 O_2(g)=Fe_2TiO_5(s)+TiO_2(s) almost completed in about 20 minutes at temperatures of 1173 and 1223 K both for the two kinds of ore in 5%O_2-Ar gas mixture. The experiment that changed the cooling rate after the oxidation was also conducted because the nature like crystalline of the rutile formed might be influenced by the cooling rate after the oxidation by fluidized bed.(2) The leaching of the oxidized ore was carried out both with sulfuric and p … More hosphoric acid solution. The fractional leach rate of the pseudobrookite tended to become larger with decreasing the cooling rate, and the slow cooling of 5K/min was more suitable. On the other hand, the leach rate of the rutile was 10% that was about one-third of the case of air-cooled. Therefore, the effect of the cooling rate was significant in terms of the fractional leach rate of the rutile.(3) The process assessment for the two processes which were the oxidation followed by diluted-acid leaching and the conventional sulfuric acid processes was conducted by calculating and comparing the amount of energy required and the amount of the CO_2 exhaust. Based on the stoichiometric oxidation reaction, the amount of energy required in the process proposed by the present authors was estimated 11.4 MJ less than the sulfuric acid process, and that of the CO_2 exhaust was 0.9kg less per 1kg TiO_2, respectively. This indicates that the proposed process is superior and favorable compared to the conventional sulfuric acid process. Less