| 摘要 |
<p>PURPOSE:To remove efficiently Bi, silver, oxygen in copper by adding sulfide to copper contg. Bi and/or silver, and refining said material in vacuum. CONSTITUTION:Sulfide is added to copper contg. Bi and/or silver such as crude copper or copper scrap obtained by treating matte in P.S converter in dry copper smelting process, and vacuum refining is performed. Therein, zinc sulfide is preferable as sulfide, has affinity with oxygen in crude copper, reduces bismuth oxide to vaporize and remove it, further removes also oxygen in crude copper. RH or DH degassing apparatus is used as the apparatus with preferable vacuum degree of about 0.5-1.0 Torr. it seems that, oxygen is removed as SO2 by S in sulfide, sinc sulfide and Bi are changed to ZnO and metallic Bi respectively, and Bi is removed faborably. Desilverization is also performed. After the treatment, ZnO is floated up to copper surface and can be removed simply.</p> |
