| 摘要 |
<p>PURPOSE:To effectively recover Zn, In and Ag by combining a process of heating a substance contg. Zn, In and Ag to a specified temp. or above after adding a reducing agent and a chlorinating agent with a process of treating the substance at a specified temp. or above in an oxidizing atmosphere after adding a chlorinating agent. CONSTITUTION:This method relates to the treatment of a substance contg. Zn, In, and Ag such as residue discharged by the dry or wet refining of Zn. The substance is regulated to a fixed grain size, and it is treated at >=800 deg.C after adding a reducing agent such as anthracite, brown coal or coke a chlorinating agent such as calcium chloride or ammonium chloride. The substance is then treated at >=800 deg.C in an oxygen atmosphere after adding a similar chlorinating agent. The 2 processes may be carried out in the reverse order. Prior to the treatments Zn is removed as required. In a wet process, sulfuric acid is added to the substance, and Zn is leached out by roasting. In a dry process, the substance is reduced with a reducing agent at >=900 deg.C. Thus, Ag is volatilized first, and In and Zn are recovered by volatilization as chlorides.</p> |
