| 摘要 |
<p>PURPOSE:To flake off only copper effectively without accompanying the generation of poisonous gas, by making the material covered with copper on niobium base alloy as anode and electrolyzing in a specified electrolyte. CONSTITUTION:In case of necessity for exposing alloy surface flaking off copper from the material of ultra conductive wire etc. composed of niobium base alloy covered with the copper, direct current electrolytic treatment is carried out making the above material as anode in the electrolyte containing 0.2-5mol/l of (NH4)2SO4 and limiting the quantity of chlor-ion at less than 0.1g/l. On this occasion, alloy itself is dissolved when electrolytic voltage is not limited at less than 30V. By the above method, dissolved copper is recovered on the cathode plate as metallic copper and there is no danger of generating poisonous gas, such as NOx etc., like nitric acid treatment method.</p> |
