F. Hernáinz Bermúdez de Castro

Influence of quebracho and sodium silicate on flotation of celestite and calcite with sodium oleate

Abstract A study has been carried out on the action of the depressants quebracho and sodium silicate on the flotation of the mineral species celestite and calcite, using sodium oleate as the collector and with a particle size below 200 mesh A.S.T.M. The experiments were performed on pure minerals in a 3 L mechanical flotation cell (subaeration) equipped with a 1 6 CV, 1500 r.p.m. engine. The results obtained indicate that quebracho is more effective on calcite than on celestite, although at concentrations above 0.12 g/L, quebracho completely depresses both minerals in the pH range between 7 and 10. The depressor action of Na 2 SiO 3 on calcite is greater on lower concentrations of sodium oleate. The significance of the depressor action of sodium silicate on celestite is low at concentrations below 10 −3 M. Moreover, various celestite-calcite mixtures have proved to respond to flotation according to the concentration of the depressant, although independent of the mixtures proportion.

The influence of temperature during flotation of celestite and calcite with sodium oleate and quebracho

Abstract A study has been made on the influence of temperature during flotation of the celestite and calcite mineral species, using sodium oleate as the collector and quebracho as the depressant, for a particle size ranging between 80 100 A.S.T.M. mesh ( 177 149 μ m ). The experiments were conducted on pure minerals in a thermostatted Hallimond tube with working temperatures between 293 and 323 K. Results indicate that celestite can be depressed during flotation with sodium oleate due to the action of quebracho, although when the temperature in the bath is increased, the depressor action is slightly inhibited, thus increasing recovery of the mineral. The results for calcite show similar findings, although with a less pronounced depressor effect due to quebracho.

Flotation rate of celestite and calcite

Abstract This paper studies several kinetic aspects of semi-batch flotation of celestite and calcite in a mechanical or subaeration cell with sodium oleate as the collector agent, using pure minerals ranging in size between 177 and 74 μm, respectively, with a constant pH = 9 in the flotation bath in all experiments. The results obtained indicate that both minerals float rapidly and that the flotation rate constant responds to a non-integral order equation. An increase in collector agent concentration also tends to level out flotation rates in both minerals.