| 摘要 |
1,243,798. TiO 2 concentrates. BRITISH TITAN Ltd. 14 July, 1969 [14 Aug., 1968], No. 38811/68. Heading C1N. Titaniferous ore containing a substantial quantity of iron oxide is beneficiated by reducing the iron oxide and removing it by leaching the ore; chlorinating the leached ore with Cl 2 gas in presence of a reducing agent so that remaining iron and other chlorinatable impurities are converted to volatile chlorides without any substantial chlorination or loss of TiO 2 , and removing the volatile chlorides from the ore. Reduction may be carried out by heating the ore, e.g. 800-1300‹ C. with a source of carbon, or in a reducing gas, e.g. N 2 or CO, or by sulphiding in presence of oxygen. Leaching may be effected by refluxing with aqueous acid, e.g. HCl, H 2 SO 4 , CH 3 COOH. Chlorination may be carried out at 800-1100‹ C. by passing Cl 2 through a fluidized bed of powdered leached ore and a reducing agent such as coke, the waste gases being cooled to solidify the volatile chlorides formed. Loss of TiO 2 can be prevented by stopping the chlorination while sufficient iron remains in the ore, e.g. 0.2-1% as oxide, to react with any TiCl 4 formed. |
