Development of New Rutile Extraction Process and Titanium Resources

对澳大利亚和莫桑比克的天然钛铁矿进行了沸腾床氧化和酸浸试验，以确定新开发的金红石提取工艺的最佳工艺条件。主要研究结果如下：(1)通过对氧化前后样品的X射线衍射和电子探针分析，发现钛铁矿(FeTiO_3)在沸腾床反应器中被氧化，生成了拟钛铁矿(Fe_2TiO_5)和金红石(TiO_2)两种相。在5%O2-Ar混合气体中，2FeTiO3(S)+1/2O2(G)=Fe2TiO5(S)+TiO2(S)在1173K和1223K的氧化反应几乎在20min内完成。氧化后的金红石的结晶性质可能受氧化后的冷却速度的影响而改变了氧化后的冷却速度。(2)氧化后的矿石分别用硫酸和p-…进行了浸出更多的磷酸溶液。随着冷却速度的降低，拟镁橄榄石的浸出率趋于增大，5K/min的慢速冷却更合适。另一方面，金红石的浸出率为10%，约为风冷浸出率的三分之一。因此，冷却速度对金红石的浸出率有显著影响。(3)通过计算和比较氧化-稀酸浸出和常规硫酸两种工艺的能耗和CO_2排放量，对两种工艺进行了工艺评价。根据化学计量比氧化反应，作者提出的工艺比硫酸工艺所需能量减少11.4mJ，每1 kg二氧化钛排放的二氧化碳能耗减少0.9公斤。这表明，与传统的硫酸工艺相比，该工艺具有优势和优势。较少

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