Zinc concentrate is the result of a flotation process after the zinc ore has been mined and milled. Zinc concentrate is an intermediate product used as raw material in the production of zinc metal. The quality of different zinc concentrates can vary but zinc sulphide concentrates are the most common and they typically contain 45-55 per cent zinc and 30 per cent sulphur. Besides zinc and sulphur they generally also contain iron, lead and other impurities. Some zinc concentrates also contain precious metals.
Boliden currently produces zinc concentrate at its mines in the Boliden area and Garpenberg in Sweden and Tara in Ireland.