Improvements in the treatment of complex minerals containing tin and/or copper, iron, arsenic, sulphur and the like and associated base and precious metals in combination or otherwise

摘要

299,750. Wilder, F. L., Morris, E., Schiff, E., and King, E. S. July 30, 1927. Treating ores to remove undesired constituents and to facilitate concentration. - Complex minerals, for instance tin-bearing sands, are washed with a solution comprising persulphates and chlorides of an alkali metal and ferric salts, whereby the very fine particles are dissolved out and a residue left suitable for concentration, as by a gravity process. Free chlorine may be present in the washing solution and at least a, part of the ferric salts may be formed in situ when the ore treated contains soluble iron. A specified solution contains sulphuric acid, sodium chloride, bisulphate, and persulphate, persulphuric acid, ferric chloride and sulphate, and free chlorine. From the separated washing solution dissolved metals, such as copper or tin, may be precipitated by iron, and a part or the whole of the mother-liquor may be regenerated, if necessary, by electrolysis before being used. Sulphur dioxide and chlorine, or the former dissolved in a solution of sodium chloride, may be added during the regeneration step.