| In contrast to polyelectrolyte flocculants, latices possess a certain degree of hydrophobicity, are compatible with flotation collectors and can be considered for use in a flotation circuit. In this study, three latices, polystyrene (PS), poly(2-ethylhexylmethacrylate) [P(EHMA)] and copoly(methyl acrylate - acrylic acid) [P(MAAA)] were prepared, characterized and tested in the flocculation and flotation of fine salt-type minerals (e.g., fluorite, apatite and calcite).; The flocculation results with all the tested latices reveal that, at a same dosage of latices and their natural pulp pH, the P(EHMA) latex produced a higher flocculation recovery of fluorite, apatite and calcite than the other two latices, polystyrene and P(MAAA). The P(EHMA) and P(MAAA) latices all exhibit a higher flocculation recovery of fluorite and apatite than calcite. The difference of degree of flocculation of fluorite, apatite and calcite is even greater when the P(MAAA) latex was used.; The addition of small amounts of dispersants, sodium tripolyphosphate and sodium silicate increases the apatite recovery and the P2O 5 grade in the selective flocculation with the P(MAAA) latex from apatite-calcite and apatite-silica mixtures. At a P(MAAA) dosage of 1.1 kg/t, pH around 9.1--9.4 and 4 ppm of sodium tripolyphosphate, 60% of the apatite can be recovered from a 1:1 apatite-calcite mixture, with a 33% P2O5 grade. At a higher dosage of P(MAAA) latex and the same other conditions the apatite recovery can be increased to 90% while the P2O5 grade was not significantly changed and remained at around 33%.; The use of the P(MAAA) latex in the flotation of fine (100% -38 mum) apatite and phosphate ore was evaluated via Hallimond tube and batch flotation tests. The latex enhances the flotation of the fine apatite at pH around 9. (Abstract shortened by UMI.)... |
