Influence of calcium ion on flotation of ilmenite and titanaugite

The solubility behavior of mineral surface ions and effects of Ca2+ on flotation of ilmenite and titanaugite were investigated.The results show that the addition of Ca2+ into pulp has little impact on ilmenite flotation,while it can activate titanaugite flotation.Large numbers of Ca2+ may dissolve into pulp from mineral surface in flotation process.When solvent ions are removed,the floatability of ilmenite changes little under weak acid pH condition but deteriorates obviously under the alkaline pH condition.On the other hand,the poor floatability of titanaugite is found in the whole pH range.Addition of Ca2+ into flotation pulp which is isolated from solvent ions will partly recover the floatability of these two minerals under alkaline condition.The main reason of activation of titanaugite is that Ca2+ increases active sites for the oleate adsorption on the surface of titanaugit which results from the adsorption of carboxyl complexes and precipitation of hydroxide of Ca2+.