Selective flotation of Maton (India) phosphate ore slimes with particular reference to the effects of particle size

Abstract

The “crusher slimes” (all passing 37 μm) from the Maton rock phosphate plant (India) were successfully floated using sodium oleate at a reagent dosage which is very different from what is required to float the coarse ore in the plant. While 0.5 kg/t of sodium oleate (with no depressant) was found to be sufficient for the flotation of slimes, the relatively coarser ( −105+44 μ m ) fraction of the ore required 2 kg/t of sodium silicate and 4 kg/t of sodium oleate for satisfactory results. Batch flotation experiments conducted on a synthetic ore feed consisting of a 1:1 mixture of coarse and slimes fractions clearly demonstrated the beneficial role of “split conditioning”. The presence of reagentized slimes (conditioned separately) seemed to facilitate the flotation of relatively coarser particles due to hydrophobic aggregation between coarse particles and slimes.