| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for removing tin in crude copper by dry type refining where the content of tin in crude copper can be made into a low level, and further, the content of tin can be controlled to≤0.33 mass%. <P>SOLUTION: In the dry type refining method, copper, noble metal scrap raw materials including copper, at least one or more kinds of noble metals selected from gold, silver, platinum, rhodium and ruthenium, and tin are melted and reduced together with a solvent and a reducing agent, after separation into the reduced slag and the reduced metal, the melted and reduced metal is subjected to oxidative crude refining for 0.5 to 7 hr with air at a flow rate of 0.5 to 3 L/min/kg-metal, and, in the case the grade of the copper in the crude copper after the oxidative crude refining is <4 mass%, sodium hydroxide is added by an equivalent of 4.5 or above to the tin in the crude copper, and the same is melted and oxidized for 0.5 to 3 hr with an oxygen-containing gas at a flow rate of≤3 L/min/kg-metal, thus the tin in the crude copper is removed to a grade at which the electrorefining of the copper is possible or below. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
