Zinc from Zincblende

1. The ore zincblende (made mostly from Zinc Sulphide) is crushed and put into water through which air is blown. Rock particles sink and the zinc sulphide floats in a froth which is skimmed off and dried. The product of this stage is 55-75% Zinc
2. The Zinc Sulphide is converted to Zinc Oxide by strong heating in a furnace:

ZnS + 3 O2  -> 2 ZnO + 2 SO2

3. Zinc Oxide is mixed with coke in a furnace and heated to 1400 °C where it is reduced to zinc: ZnO + C -> Zn + CO
4. The zinc metal produced cools and the carbon monoxide is burnt, with the heat given out to help reduce costs of the