COLLECTING METHOD OF HIGH PURITY INDIUM FROM SULFURIC ACID ACIDIC SOLUTION CONTAINING INDIUM

摘要

PURPOSE:To collect In of high purity with high efficiency by use of a comparatively simple device, by adding NH4Cl to coarse In obtained by cementation from a sulfuric acid acidic solution containing In, heating and melting it, and separating the dross. CONSTITUTION:To a sulfuric acid acidic solution containing In, alkali is added, its pH is set to 0.5-1.2, and to In in this solution, Zn-Cd alloy powder of 1- 1.3 equivalent or Zn powder of high purity is added, by which cementation is executed. As a result, coarse In obtained by deposition and separation is melted in thick hydrochloric acid, cementation is executed by soaking an In plate into said hydrochloric acid, a precious metal is deposited and separated from the In, and after that, deposit containing In is obtained by executing the same cementation as the process in which said coarse In has been obtained, it is melted by alkali, and coarse In is obtained. Subsequently, NH4Cl being =2wt% by external division is added to said coarse In, it is heated and melted, generated dross is separated, and In of purity being = about 99.99wt% is obtained with actual yield being = about 85%.