| 摘要 |
PURPOSE:To recover metallic tin from tin sludge contg. stannic salts at a low cost by dissolving the sludge in an aq. soln., filtering the soln., treating the resulting filtrate with sodium hydroxide, reducing quatervalent tin ions in the filtrate with a reducing agent and electrolytically refining the filtrate to electrodeposit tin. CONSTITUTION:Tin sludge contg. stannic salts or stannous salts and stannic salts is dissolved in an aq. soln. by properly adding an acid or alkali or by heating and stirring. The soln. is filtered to remove undissolved matter. The resulting filtrate is treated with sodium hydroxide and heavy metals such as iron are filtered off as hydroxides. A reducing agent such as ascorbic acid is added to the filtrate to reduce all or part of quatervalent tin ions to bivalent tin ions and then the filtrate is electrolytically reduced to electrodeposit tin. Thus, metallic tin is recovered with small consumption of electric power.
|
