Reduction of zinc oxide in manganese furnace dust with tar

Abstract

Manganese furnace dust is formed when volatiles and fines are cleaned by wet scrubbers from the off-gases from manganese alloy smelting furnaces. Impediments to the recycling of the manganese furnace dust back to the ferroalloy furnaces are handling due to the presence of tar, and the potential accumulation of zinc in the furnaces, which can cause irregularities in their operation. This paper examines reduction of zinc oxide from manganese furnace dust formed during ferromanganese and silicomanganese production at Tasmanian Electro Metallurgical Company. Zinc oxide was reduced by tar in the furnace dust above 800°C. The reduction rate increased with increasing temperature with almost complete zinc removal at 1 100°C. The effects of gas atmosphere, pellet size, pressure applied in pellet preparation, as well as mixing of furnace dust with manganese ore, on zinc oxide reduction and removal were studied. © 2006 ISIJ.