030308 Secondary zinc productionEuropean Commission
rotary kiln or submerged combustion slag fuming. In both cases zinc oxide in the slag is reduced to metallic zinc (vapor) by carbon oxidized by secondary air and carried out in the furnace gases for recovery of zinc oxide dust. Zinc recovery rotary kilns (Waelz kilns) are up to 95 m long with an internal diameter of up to 4.5 m and they are