GB633776A - Improved processes and apparatus for the vacuum flotation treatment of coal, ores and the like - Google Patents

Abstract

633,776. Froth flotation. SUTTON, W. J. June 11, 1947, No. 15394. [Class 82(ii)] In a process for the vacuum flotation-treatment of ores, coal and the like, re-treatment of the waste product, or of the clean or concentrated product, is effected simultaneously with the primary treatment as a continued operation in a single apparatus. The apparatus shown in Fig. 1 comprises a main separation chamber 1 of double conical formation. An overflow trough at the top of upper cone 2 serves to maintain a constant liquid level in chamber 1. Concentrically within the chamber 1 is a cylinder 5 which forms a re-treatment chamber with its upper edge slightly above the constant liquid level in chamber 1 and its lower end joined to a truncated cone 6 which is connected to a cylindrical outlet fitting 7 surrounding a centrally disposed outlet pipe 8 by which clean flotation product leaves the apparatus. The cylinder 5 contains a series of spaced cones 11, 12, 14, Fig. 3, which, with orifices 28 and 29 in cylinder 5, ensure the separate removal of the various products from the apparatus. Orifices 30 ensure constant level of liquid in the cylinder and chamber 1. When applied to the treatment of coal, pulp to be treated is supplied to chamber 1 by supply conduit 32, Fig. 1, branched to distributers 33. Air may be added to the incoming pulp through a diffuser 34. The refuse from this primary treatment is discharged by outlet fitting 36 and pipe 37 and is supplied to cylinder 5 by pipe 17, Fig. 3, having a tangential discharge 18, thus giving the pulp a rotary motion. As the coal-laden froth rises the rotary motion is arrested by baffles 16 and the froth overflows through orifices 26 to compartments 25 of radially-spaced launders 19. from which it is discharged by orifices 29 and pipe 8. Refuse from this re-treatment sinks through cone 14 to cone 12 and passes away by pipe 13. At the same time in chamber 1, outside cylinder 5, and in the spaces between launders 19, coal-laden froth rises and passes over lips 20 of launders 19, Figs. 1 and 5. The froth is directed by angularly adjustable guide plates 23 over screens 22, which are preferably at an angle of 45 degrees to the horizontal, and is freed of a large part of its water content which is removed by compartment 24, orifice 28, Fig. 3, cone 6, fitting 7 and pipe 10. Specification 505.688 is referred to.