EARTH

[3801-11-01] EAF Dust and Secondary Fly Ash Treatment by MF Process at Miike Smelter

○Hiromitsu Sugano¹, Shuichi Hatae¹ (1. Miike Smelting Company Limited)

Chairman: Chompunoot Wiraseranee （Mitsubishi Materials Corporation）, Liu Hui (Central South University)

Keywords:zinc, recycling

MF is a half shaft blast furnace which has been developed at Mitsui Miike Smelter in the 1960’s to treat vertical retort residue. The MF has also been tested for treatment of various recycling materials and wastes. Now various secondaries and wastes (EAF dust, Secondary Fly Ash, etc.)are mainly treated. Secondary Fly Ash from the Melting process contains heavy metals such as zinc, lead, copper and etc. In addition, it is necessary to remove chlorine by pH controlled washing treatment process because of containing up to 20% chlorine. Concentrated heavy metals by washing process are blended with other waste materials to recover these heavy metals by MF process. Before being fed to the furnace, these blended raw materials are briquetted with reductant.These heavy metals are recovered in the form of crude zinc oxide, matte, slag. Zinc and lead are concentrated in crude zinc oxide, copper and silver are contained in matte.
The MF can be widely applied to many kinds of materials which contain such non-ferrous metal-valuables. In addition, the improvement in operation and technology by oxygen enrichment has effectively made the unit capacity much larger.