FROTH-FLOTATION OF SULFIDIC, OXIDIC AND SALT-TYPE MINERALS

Selective foam flatation of sulphide, oxide and salt type ores is claimed in which the latter are wet-ground to flotation fineness and the obtd. slurry is prepd. and subjected to foam flotation, is improved by using, besides the collector, a polysaccharide, a lignosulphonate, a quarcum and/or a chemical surfactant additive, which prevents the collector from adhering to the silicate surfaces and renders them hydrophilic or lowers the hydrophilic character of the ores to which the collector has already adhered. The collector and the additive may be added at the grinding stage. Process is partic. applicable to Ni sulphide ores but can also be applied to other non sulphide ores e.g. Scheelite, ilmenite, apatite and magnesite. Addition of the additive results in improved yield and improves selectivity and can be effected without requiring costly emulsifying equipments. The additive improves the flow properties of the slurry to the extent that it is not necessary for the density of the slurry to decrease by a value as large as in prior art. Flotation can be effected at a slurry density of 25-30%, using less water.