| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electrolytic refining method for silver, by which the impurity grade in electric silver is efficiently reduced by a simple constitution. <P>SOLUTION: In the electrolytic refining method for silver, crude silver containing lead and copper is used as an anode electrode, and a silver nitrate solution having a pH of 1.0-4.5 and containing 40-70 g/L of silver and 5 g/L or less of nitric acid is used. The electrolytic refining method for silver is carried out under such conditions that the solution temperature is 15-35°C and the current density is 250-350 A/m<SP POS="POST">2</SP>while controlling the lead concentration and copper concentration to 1.0 g/L or less and 1.0 g/L or less, respectively, in the silver electrolytic solution during electrolytic refining. <P>COPYRIGHT: (C)2012,JPO&INPIT |
