Extraction of zinc from zinc blende is achieved by

Zinc blende  ZnS  also contains some PbS. The latter skimmed off by using pine oil during the froth floatation. Once PbS is removed,froth floatation helps dress (or concentrate) Zinc blende. Post concentration, it is roasted to convert ZnS into ZnO. Then it is smelted  with excess coke to minimize the production of CO2 or else carbon dioxide may oxidize metallic zinc back to ZnO.