| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a process for producing metallic cadmium which possesses a mercury-removing step. <P>SOLUTION: Cadmium carbonate, derived from a gas-washing liquid generated in a removal facility for washing and removing dust or harmful substances evaporated during a zinc- or lead-sintering step, is dissolved in sulfuric acid to obtain a cadmium sulfate solution. Alternatively, zinc cadmium slag is dissolved in sulfuric acid to obtain a cadmium sulfate solution. Crude cadmium or electrolytic zinc is added to the cadmium sulfate solution to obtain sponge cadmium via cementation, and the sponge cadmium is dissolved to obtain crude cadmium. The crude cadmium is distilled to obtain distilled cadmium, which is cast to obtain a product. Here, prior to cementation, cadmium metal is added in a proportion of 3.5-5.6 kg, in dry weight, per 1 m<SP>3</SP>of 60-120 g/L cadmium sulfate solution. <P>COPYRIGHT: (C)2003,JPO</p> |
