タングステン等特殊鉱物製錬の合理化

抄録

The metallic tungsten of the highest purity has been required in the fields of hard metals, electronics and special alloy steels, so the ores which includethe impurities only a little have been selected as the raw materials.
But the low grade complex ores containing many kinds of impurities such as Mo, P, Cu, Sn, Ni, or As, of Ôtani Mine were treated successfully by the improved processes to yield the high purity metal.
The physical treatments of the gravity concentration, the flotation and the electrostatic separation were applied and the concentrates of W0₃, Cu-sulfide, Fe-sulfide and Sn+WO₃ were obtained at a high recovery. The concentrates of WO₃ and Sn-i-W00 were treated by the method of the autoclave leaching of Na₂CO₃ solution at Kanzakigawa and the impurities above mentioned were removed from the leaching solution by the chemical methods and the artificial CaWO4 of the high purity were precipitated.
Furthermore this artificial CaWO4 was dissolved with HC1 solution and from this solution the WO₃ was prepared and it was reduced to metallic W in the hydrogen furnace.
At Uji factory the covered type electric furnace were adapted for smelting ferro-tungsten and by this method the flue dusts were completely recovered, so the total recovery percent of tungsten were incleased.
These procedures and also other refining methods or low grade complex ores from abroad are reported in this paper.