| 摘要 |
<p>PURPOSE:To produce the title copper material having a high residual resistance ratio from the high-purity copper wherein the contents of silver and sulfur are reduced below a specified value. CONSTITUTION:The superconductive copper material is formed from the high- purity copper contg. <=1ppm silver and <=0.5ppm sulfur. The copper material is produced by the following method. Namely, a continuous casting device, wherein one end of a casting mold 10 protrudes into a molten metal bath 11 and the other end is brought into contact with a cooling structure 12, is used, and the melt consisting of the high-purity copper contg. <=1ppm silver and <=0.5ppm sulfur is continuously cast to obtain a pipe material. In the production of the pipe material, the electrolytic copper previously obtained by electrolysis or the electrolytic copper obtained by electrolyzing the equivalent in a mineral acid electrolyte is preferably used as the high-purity copper used for the melt. In addition, the removal of silver from the electrolyte is preferably carried out by bringing the electrolyte discharged from the anode side into contact with metallic copper, and/or using a chlorine ion.</p> |
