| 摘要 |
<p>Metals are extracted from ores which exist in the form of oxides or sulphides, by treating the ore with hydrogen fluoride and/or fluorosilicic acid. There are two preferred forms. When hydrogen fluoride is used, the ore is initially crushed, dried and then contacted with HF gas at temperatures above 105<o>C to produce metal fluorides. The metal fluorides are then contacted with aqueous HF solution and the resulting insoluble metal fluorides and iron oxides are separated from the solution, and metal fluorides preferably including nickel and cobalt fluorides are recovered. When fluorosilicic acid is used, the crushed and dried ore is directly contacted with an aqueous solution of fluorosilicic acid at temperatures above 70<o>C and the resulting insoluble metal fluorides and iron oxides are separated and metal fluorides preferably including nickel and cobalt fluorides are recovered. Preferred ores are cobalt-nickel lateritic ores.</p> |
