GB802433A - A process for the separation of magnetisable and contaminating non-magnetisable particles present together in suspension in a liquid, and apparatus therefor - Google Patents

Abstract

802,433. Washing granular materials. STAMICARBON N.V. Aug. 4, 1955 [Aug. 11, 1954], No. 22494/55. Class 82(2) Magnetizable and contaminating non- magnetizable particles in suspension in a liquid, e.g. as in the heavy separating medium for a coal or ore washing process, are separated by a process which includes feeding the suspension to a magnetic separator 8 which removes the bulk of the magnetizable particles at 9, whilst the remaining suspension containing the rest of the magnetizable particles is wet screened at 13 to separate at least part of the said magnetizable particles from coarser contaminating particles using the method of any of Specifications 791,520, 791,857, 791,858 or 791,859 [all in Group I]. In the method and appartus described, raw coal is fed at A, the resulting coal and shale fractions being discharged at B, C respectively after separation in a magnetite suspension. Dilute suspension obtained by continually rinsing the separated fractions is led via 2 to a preliminary screening such as by the curved deck of spacer bars 3 (where the method of Specification 791,520 may be used), or by a cyclone or thickener. About 90 per cent with fine magnetite passes through to tank 4 and thickener 6, the remainder being led to the magnetic separtor 8 whence the magnetite collects at 9 and is led to thickener 6 while the non-magnetic and fine magnetite particles collect at 11 and are led to the wet screening deck 13 for separation treatment by the method of any of the above Specification 791,520, &c. The fine particles collect at 14 and may either be returned via 15 to the regenerating circuit, or led to thickener 6; the coarsest particles are discharged at 16. Part of the overflow from thickener 6 is preferably re-introduced via 17 to the wet screen 13, while part may be discharged at 18; the remainder being led back via 20 for use in rinsing the coal and shale fractions. Thickened suspension returns via 19 to the coal washing apparatus for re-use as the heavy separatory medium.