| 摘要 |
PURPOSE:To separate and recover heavy metals as much as possible and to regenerate a ferric chloride soln. by treating the mixture of the waste etchant from the production of electronic parts and the waste etchant of a shadow mask that is the waste ferric chloride soln. contg. the valuable heavy metals such as copper, chromium and nickel as the object. CONSTITUTION:A waste ferric chloride soln. is added with a specified amt. of iron material and controlled to pH<1.5 to deposit and remove copper in the first stage. The soln, is mixed with a specified amt. of iron material and controlled to pH 1 to 3 to deposit and remove chromium in the second stage. The soln. is mixed with a specified amt. of the iron powder produced from Hoeganes ore and controlled to pH<3.5 to deposit and remove nickel in the third stage. The soln. treated in the third stage is chlorinated to regenerate ferric chloride in the fourth stage. Consequently, the valuable heavy metals are separated and removed, and the ferric chloride soln. is regenerated at a low cost. |
