摘要 |
1373843 Zinc sulphide and sodium aluminate PECHINEY UGINE KUHLMANN 21 Feb 1972 [22 Feb 1971] 7880/72 Heading C1A Zinc, remaining in a sodium aluminate liquor after attacking a zinc containing bauxite, is removed by the addition of sodium sulphide, to the liquor after dilution, in a quantity of from 0À125 to 0À20 g. of 5<2-> per litre of liquor in order to precipitate zinc sulphide. Zinc is added to the liquor, before its separation from a red mud, in a quantity such that the zinc sulphide content, just prior to precipitation is at least 0À18 g./1. of aluminate liquor. The zinc and sodium sulphide may be introduced into the liquor just before decantation of a red mud from the liquor or the zinc may be added, preferably as zinc blende in admixture with the bauxite, prior to attack by the liquor. |