GB401720A - Improvements in or relating to the flotation concentration of ores - Google Patents

Abstract

In the flotation concentration of ores, particularly ores in which the values are intergrown with the gangue, the ore is coarsely ground and concentrated by flotation to give a concentrate rich in values, the unfloated part of the ore is then subjected to a second flotation operation to give a second concentrate, and this concentrate, after the whole or the coarser particles thereof have been reground, is again concentrated by flotation to recover the remainder of the values. The process is described with reference to the concentration of copper sulphide minerals, e.g. chalcopyrite mixed with pyrites, and to the differential separation of galena and blende. In concentrating chalcopyrite the ore after coarse grinding is floated in an alkaline pulp containing thiocarbanilide, sodium cyanide, and pine oil. After removal of the concentrate, pine oil and xanthate are added to give the second concentrate which is reground in an alkaline pulp, conditioned with sodium cyanide with or without xanthate, and reconcentrated. In the differential separation of galena and blende the ore is coarsely ground in water containing sodium cyanide and lime or soda ash and is then concentrated with cresol and xanthate. After removal of the concentrate, a further concentrate is obtained by re-agitating with more cresol and xanthate with or without copper sulphate. The coarse particles of this concentrate are reground with sodium cyanide, zinc sulphate, and lime or soda ash and the whole concentrate is then reconcentrated with cresol and xanthate. The froth obtained may be re-cleaned by treatment in the presence of sodium cyanide, soda ash, and zinc sulphate.