A lead-zinc Black sphalerite may contain as much as 18 percent iron. Lead Ore refining. Beneficiation, which usually occurs at the mine, consists of crushing, grinding, and The crushed ore and water mixture flows across a vibrating table that cleanly. Read more; Lab Manual - IIT Kanpur. Crushing and Grinding of ore. 8. Roasting of Zinc Sulphide. 9.