Activation and depression of calcite in calcium minerals flotation

In the flotation of scheelite ore containing fluorite and calcite, the treatment of calcite is important to obtain satisfactory scheelite and fluorite concentrate. It is better in scheelite rougher flotation to activate calcite with Na2CO3 and to float it into scheelite rough concentrate, than to depress calcite into fluorite flotation operation like the conventional process. By activating calcite with Na2CO3 in scheelite rougher flotation the fluorite flotation can be carried out more easily, and the fluorite concentrate with a grade of CaF2 97.42% and CaCO3 0.73%, compared with that of a grade of CaF2 95. 78% and CaCO3 1.54% without Na2CO3, was gained. The calcite,which was activated and floated into scheelite rough concentrate, can be depressed and removed with Petrov's process or acid leaching, so it has no obvious negative effect on scheelite concentrate. The mechanism of activation is due to home-ion effect of Na2CO3 in calcite pulp.