A Study On The Separation Of Iron-Aluminum-Silicon Of Iron And Silicon-rich Diaspore-type Bauxite Ore

Iron and silicon-rich diaspore-type bauxite is one of the typical refractory ores abundantly distributing in our country. As no technology can take good advantage of this resource, how to realize comprehensive utilization is of greater significance under the increasing need of bauxite.The paper took the diasporic bauxite from Yunnan for study, and conducted experiments and mechanism of efficient separation of aluminum, iron and silicon.The innovation is to transform hematite into magnetite and activate SiO2from silicon ores by using a magnetic roasting. Then carried desilication through leaching in caustic alkali solution and milling-magnetic separation to obtain high-quality bauxite ore and qualified iron ore concentrate.Technological mineralogy indicated:A/S is2.1. The raw ore has a36.67%Al2O3existed by diaspore,19.05%TFe existed by hematite and12.88%SiO2existed by kaolinite. It is difficult to realize the separation of Al-Fe-Si minerals by the way of conventional method for dip dyeing of different minerals.An exploration of activated roasting-alkaline leaching to realize the separation of Al-Si was carried, bauxite residue that A/S is11.93was got and whose disilication rate is79.73%under the optimized parameters. A good result of desilicication could be got by the oxidizing roasting, but there was little difference among the magnetic products and raw ore. Magnetizing roast is in a weakly reducing atmosphere, and a-Al2O3and SiO2were got by the breaking of the silicon minerals at the same time. After alkaline leaching and magnetic separation, the iron ore concentrate which had a55.11%TFe and a recovery of73.88%and bauxite ore concentrate which had a64.62%Al2O3and a10.59A/S were got.The balance computation of iron minerals thermodynamics indicates that CO concentration needed in the process of hematite transformed into magnetite is only0.001%, this is close with the actual CO concentration of0.5%. The ΔG of magnetite, ilmentite and fayalite in the reaction process increased in turn, and the possibility of each product declined, this is the reason of large emerge of magnetite but little ilmentite and fayalite.