Flotation process for improving recovery of phosphates from ores

Abstract

A flotation process is provided for beneficiating phosphate ores in at least two floats after conditioning with 0.1-1.5 pound per ton of fuel oil and adding 0.025-0.1 pound per ton of a frother and 0.2-0.5 pound per ton of a polyamine cationic collector to remove silica in the froth (tails) and obtain 75-84% recoveries of phosphate in the concentrate (sink) which contains no more than about 6% insol. For some ores, the floats can be made on each fraction, after desliming thereof, which are obtained by screening over a 35 mesh screen. For other ores, desliming and a rougher flotation are initially needed. The silica froths (rougher tails) from this float are then cleaned and recleaned in separate floats, without additional conditioning or addition of collector to produce tails which are discarded and a combined sink which is screened over a 48 mesh screen to produce a +48 mesh fraction which is discarded and a -48 mesh fraction which is concentrate (product). Depending upon the ore, the sink from the first float is directly usable as product or is screened over a 35 mesh screen to produce a -35 mesh concentrate (product) and a +35 mesh fraction which is conditioned with fuel oil, treated with a frother and collector, and floated to produce a tails, which is discarded, and a third concentrate as product.