GB901515A - Improved froth flotation method - Google Patents

Abstract

A very finely-divided multicomponent mineral mass is beneficiated by a method which includes the steps of forming an aqueous pulp of the mass in which at least one of its components is selectively oiled and which contains in intimate association with the mass collector-coated auxiliary mineral particles which are flotable in the presence of the aqueous pulp and subjecting the conditioned aqueous pulp to froth flotation. The multicomponent mineral mass and the auxiliary mineral can be treated concurrently, as an aqueous pulp with a collector reagent which selectively oils certain components of the mineral mass and the particles of the auxiliary mineral, or they may be treated separately, each in the form of a dispersed aqueous pulp which are then admixed. The component of the mineral mass which is not selectively oiled is water-wettable and becomes a machine discharge product. The materials may also be reagentized as they are being ground to a grain size suitable for flotation. Any mineral capable of being provided with an orientated hydrophilic surface coating may be used as an auxiliary, the coating being of a character such that the auxiliary mineral will be flotable in the presence of the particular reagentized feed pulp. Suitable auxiliary minerals are calcite, barytes, kyanite, silica sand, anatase and flurospar. Suitable reagents for floating the auxiliary minerals are known or may be found by experiment. The auxiliary mineral may be separated from the floated fraction, if required, by known means. The main application of the invention is to the beneficiation of kaolin clay discoloured with titaniferous and ferruginous matter. In one embodiment, an aqueous pulp is formed of kaolin and sodium silicate solution and these are added, as reagents: ammonium sulphate, ammonium hydroxide, crude tall oil fatty acid, neutral calcium petronate and a water-soluble petroleum sulphonate. An aqueous pulp is separately formed of calcite, caustic soda and crude tall oil. The two pulps are admixed and subjected to froth flotation. Other examples are given of the beneficiation of different types of kaolin, with the multicomponent mass and the auxiliary mineral reagentized concurrently or separately, and the metallurgical results are tabulated with reference, among other data, to the whiteness of the resulting clay in terms of its brightness index according to a known standard referred to.