| 摘要 |
<p>PURPOSE:To recover high-purity copper from a copper-electrolytic precipitate in a high yield by a method in which the copper-electrolytic precipitate is leached with chlorine gas to form AgCl residues, the AgCl residues are reductively melted to form rich lead, the rich lead is oxidized by oxygen to form crude silver, and the crude silver is cast in anode for electrorefining. CONSTITUTION:Copper electrolytic precipitate or copper-deprived precipitate in the electrorefining process of copper is slurried with a 1-5 N aqueous solution of the chloride (e.g., NaCl, MgCl2, etc.) of the I group or II group metal in the periodic table, and chlorine gas is blown into the slurry at 60-80 deg.C to obtain AgCl residues containing about 40-43% silver. An adequate reducing agent and an adequate brine-forming agent are added to the AgCl residues, and the AgCl residues are melted at 1,100-1,200 deg.C to form an about 70% Ag-containing rich lead. An oxidizer is blown into the work lead at 1,100-1,300 deg.C to raise the silver content to about 99% or more, the scum formed is removed, and the molten silver is cast into a crude silver plate. The crude silver plate is subjected to electrorefining to obtain a purified silver of a high purity of about 99.999% or more.</p> |
