Patent GB-418301-A (GB)
Title: Improvements in or relating to flotation concentration of minerals
IPC: B03D1/012
Filed: 1933-03-21
Abstract: Ores are concentrated by subjecting the pulp to flotation in the presence of a reagent formed by the interaction between an acid chloride and a salt of a monothio-organic acid.  The preferred salts are the alkali metal organic monothiocarbonates, but salts of acids such as thioacetic acid may also be used.  The acid chloride may be organic; chlorides referred to specifically being acetyl chloride, benzoyl chloride, cinnamoyl chloride, 1 : 3-dimethylbenzene-4-sulphonic chloride, furoyl chloride, succinyl chloride, benzene sulphonic chloride, and ethyl chlorocarbonate. The salt of the monothio acid and the acid chloride are mixed, with or without cooling, as solutions or suspensions in liquid diluents, such as acetone, ether, petroleum ether, or, in cases where the decomposition of the acid chloride is slow, water; the product being separated from the metal chloride either by pouring into water or by filtration.  Details are given of the preparation of the reagents from potassium ethyl monothiocarbonate and various acid chlorides and also of the preparation of a reagent from potassium acetate and benzoyl chloride in which the ether used as diluent is finally removed by suction and the oil obtained is filtered to separate it from benzoic acid crystals, dissolved in ether, shaken with an aqueous solution of sodium bicarbonate, and recovered by evaporation of the ether.  The use of the reagents in the concentration of copper ores and in the differential separation of lead-zinc ores is described, frothing agents such as pine oil or cresol being employed. Specifications 284,198 and 296,270, [both in Class 2 (iii)], are referred to.ALSO:Ores are concentrated by subjecting the pulp to flotation in the presence of a reagent formed by the interaction between an acid chloride and a salt of a monothio-organic acid.  The preferred salts are the alkali metal organic monothiocarbonates, but salts of acids such as thioacetic acid may also be used.  The acid chloride may be organic; chlorides referred to specifically being acetyl chloride, benzoyl chloride, cinnamoyl chloride, 1 : 3-dimethyl-benzene-4-sulphonic chloride, furoyl chloride, succinyl chloride, benzene sulphonic chloride, and ethyl chlorocarbonate. The salt of the monothio acid and the acid chloride are mixed, with or without cooling, as solutions or suspensions in liquid diluents, such as acetone, ether, petroleum ether, or, in cases where the decomposition of the acid chloride is slow, water; the product being separated from the metal chloride either by pouring into water or by filtration.  Details are given of the preparation of the reagents from potassium ethyl monothio-carbonate and various acid chlorides and also of the preparation of a reagent from potassium acetate and benzoyl chloride, in which the ether used as diluent is finally removed by suction and the oil obtained is filtered to separate it from benzoic acid crystals, dissolved in ether, shaken with an aqueous solution of sodium bicarbonate, and recovered by evaporation of the ether.  The use of the reagents in the concentration of copper ores and in the differential separation of lead-zinc ores is described, frothing agents such as pine oil or cresol being employed. Specifications 284,198 and 296,270, [both in Class 82 (ii)], are referred to.