GB505688A - Improvements relating to cleaning coal, concentrating ores and the like - Google Patents

Abstract

505,688. Washing granular materials. SUTTON, W. J., and TALBOT, H. J. Jan. 13, 1938, No. 1163. [Class 82 (ii)] In a method of purifying coal, ores, &c. by vacuum flotation, the pulp is introduced into a separation chamber at more than one point by means located within the chamber and the coal, ore or the like is withdrawn through a central outlet pipe extending substantially vertically within the separation chamber and having its open mouth situated in the upper part of the chamber from the base of which the gangue is discharged, and the process water is drawn off separately from the upper part of the chamber. In the form shown in the Figure the pulp enters the chamber 1 through internal distributer heads 3. These heads are arranged in one or more horizontal levels and each level may be supplied from different valve-controlled feed tanks such as 4 so that different sizings of material, e.g. from a duplex mixer 7, may be fed at different levels. Air by suction or compression may be introduced in the zone where the coarse coal is fed in, preferably in the upper part of the top cone. The discharge of gangue through the pipe 8 is regulated by the paddle agitator 10 and sliding valve 11. The clean coal is drawn off through the outlet pipe 15, the funnel 16 on which is adjustable in height and is level with the overflow trough 12. The separation chamber is of double-wall construction so that the water passes downwards to the opening 19 up through the space 13 and overflows over the circular trough 12 into pipes 20, 22. The vacuum is applied through the pipe 21 and vacuum smoothing tank 14. Rotary rakes 24 assist the coal into the funnel 16 and are adjustable simultaneously with the funnel.