| 摘要 |
1,265,790. Froth flotation. ALLIED CHEMICAL CORP. 22 June, 1970 [6 Aug., 1969], No. 30082/70. Addition to 1,236,684. Heading B2H. A fluorspar concentrate having a fluorspar content of at least 97% by weight is produced by:-(1) preparing an aqueous pulp containing:-(a) crude fluorspar ore containing less than 0.1 part by wt iron, expressed as FeSO 4 , per 1000 parts ore and appreciable quantities of gangue minerals but being substantially free of metallic sulphides; (b) a water-soluble ferrous salt in an amount such that the pulp contains 0.1 to 0.4 part by wt of dissolved iron, expressed as FeSO 4 , per 1000 parts ore; (c) a collector for fluorspar comprising one or more saturated fatty acids or soaps thereof either alone or mixed with one or more unsaturated fatty acids or soaps thereof, in an amount up to 70% by wt of the mixture; (d) at least one depressant for gangue minerals comprising an alkali metal silicate or metasilicate, or quebracho; (2) heating the pulp at its boiling point while maintaining the pH at 7-10; (3) subjecting the pulp to froth flotation; (4) recovering a fluorspar concentrate from the froth. The pulp may also contain guar as a depressant for clay slimes, barium sulphate and gangue minerals. The ferrous salt may be FeSO 4 . The soaps may be aluminium or alkali metal or alkaline earth metal soaps such as Na, K, Ca and Mg soaps. The fatty acids may be those containing 4-22 carbon atoms. NaOH may be used to control the pH. |
