Depressor for Sphalerite -- zinc sulphate

In the mineral processing, zinc sulfate, lime, cyanide, sodium sulfide are the commonly used depressor. Applied together with other agents, zinc sulfate is a good depressor for sphalerite.

How does zinc sulfate work in the mining?

Usually, this depressor works in the alkaline pulp, the higher PH, the more obvious inhibitory effect. In the water, the reaction of zinc sulfate is as follows:

ZnSO4＝Zn2++SO42-

Zn2+ +2H20=Zn(OH)2+ 2H+ ［Zn(OH)2 is a acid and alkali compound that’s soluble in acid condition to form salt］

Zn(OH)2+H2S04＝ZnSO4+2H2O

In alkali condition, HZnO2- and ZnO22- occur and adsorbed on the mineral that strengthen its hydrophilic.

Zn(OH)2+NaOH＝NaHZnO2+H2O

Zn(OH)2+2NaOH＝Na2ZnO2+2H2O

In mineral processing, zinc sulphate generally not be used as depressor alone and applied with cyanide, sodium sulfide, sodium carbonate, etc. The commonly used proportion is: cyanide: zinc sulfate = 1:2 ~ 5. Combination application with zinc sulfate and cyanide can effectively strengthen the depress effect.