| 摘要 |
<p>Iron is removed from a TiO2 containing ore by roasting the ore in an oxidizing atmosphere to convert all the iron to Fe2O3, reducing to convert the Fe2O3 to Fe metal, and leaching with a ferric salt solution to give an iron-free TiO2 residue and a ferrous solution, which is oxidized with an O2-containing gas at above 20 DEG C. to regenerate the ferric solution. The ore oxidation may be effected at 750-1200 DEG C. in air, and reduction at 700-1300 DEG C. with carbon, CO, or H2, or mixtures, e.g. CO + H2. Leaching may be effected at 80 DEG C. with aqueous or alcoholic FeCl3 or Fe2(SO4)3 of at least 12% concn. The ferrous solution may be oxidized with oxygen and optionally ozone at 80 DEG C., giving by-product Fe2O3. Part of the iron may be retained in the ferrous state in the solution used for leaching, e.g. in the FeIII:FeII ratio of 1.5:1. The ore may be ilmenite, and the product is referred to as "synthetic rutile."</p> |
