GB532103A - Improvements in or relating to the separation of solid materials of different specific gravities - Google Patents

Abstract

532,103. Wet-separating. BOVING, J. ORTEN-. and COLLIERY ENGINEERING, Ltd. May 10, 1939, No. 13948. [Class 82 (ii)] In the wet separation of materials of different specific gravities, especially in sink-and-float or gravity concentration processes by the employment of a suspension of a suitably ground material in an aqueous medium, the solid substance used is one which would normally be capable of swelling in an aqueous medium but which has been subjected prior to grinding to a heat treatment at high temperature such as sintering and/or calcining. The substance preferably is of an amorphrous nature and colloidal or crystalline material may be mixed with it. Examples of the materials used are clay, or silicate or aluminate which has been subjected to heat treatment and ground, ground bricks, ground concrete in which one or more of its constituents have been heat-treated before agglomeration and setting of the concrete especially that containing bauxite, the gangue or reject material from sink-and-float or other separation processes which has been heat-treated and ground or constituents of burnt-out colliery waste heaps. A dispersing or stabilizing agent such as sodium silicate, silica gel or caustic soda may be added to the suspension. The suspension may be used in pulsation processes or in processes where horizontal, upward or upward and downward currents are set up in the suspension and also in processes where the density of the suspension increases from the top downwards.