Froth flotation process

摘要

941,348. Froth flotation. HEYL & PATTERSON Inc. Dec. 4, 1961 [April 18, 1961], No. 43241/61. Heading B2H. A froth flotation process comprises the steps of progressively advancing slurry along on elongated receptacle 2, impelling into the slurry below its surface at intervals along its path e.g. through chambers 10, agitating liquid and gas causing agitation and froth formation, separating froth from the slurry, withdrawing a portion of the remaining slurry from the receptacle, at least part of the withdrawn slurry being re-impelled into the slurry and thus recirculated to constitute at least part of the agitating liquid, and delivering a tail's fraction at the end of the path. The receptacle is divided into four cells A, B, C, D by baffles 4, 5, 6. The slurry is fed in under a baffle 3 and it gradually progresses to a tails outlet 9 by way of baffles 7, 8. The chamber 10 in each cell is fed with slurry from a pump 17 tangentially through a conduit 11 so that the slurry swirls out of an outlet 12, mixes with air from a pipe 13 and distributes itself throughout the particular cell. Each cell has a pipe 18, 19, 20, or 21 with a control valve 181, 191, 201 or 211 respectively through which slurry maybe withdrawn to feed the pump 17. It has been found that the best results are obtained if the feed for the pump is taken from the cell C or the cell D, or from the outlet 9, which is in effect the same as taking it from the cell D. The baffles 4, 5, 6 may be dispensed with and in some cases the slurry withdrawn from the receptacle 2 may not form all the agitating liquid, or only part of the slurry withdrawn may be used for agitation.