Popis: |
Shisaka Smelting Co., Ltd. has recovered crude zinc oxide from electric arc furnace (EAF) dust using the Waelz kiln process since 1977. When the operation started, malfunctions frequently occurred in a granulation process which was previous process of a reduction roasting process. We stopped this process and shifted to the process directly charging EAF dust in the reduction rotary kiln. As a result, we had been weak in treating high-zinc EAF dust for a long time. To improve the disadvantage, we introduced a new granulation process which is off-line in 2011. Thereby, zinc recovery rate in reduction rotary kiln greatly increases and the capacity treating high-zinc EAF dust reaches 50,000 tons per year. |