Resource recovery of copper-contaminated sludge with jarosite process and selective precipitation



This study focuses on copper recovery from printed circuit board (PCB) sludge. The copper and other metals in the sludge were extracted with sulfuric acid, and the major metals in the leachate were copper and iron. Jarosite process was utilized to remove impurities such as iron and calcium from the leachate. The elimination percentage of iron from the leachate increased when the molar ratio of potassium/iron (K/Fe) increased in the jarosite process. When the molar ratio of K/Fe was 1.4., it was found that 18.91% of iron content was held while 92.97% of copper content remained in the leachate. The filtrate could be purified further with sulfide precipitation and its filtration characteristics were improved. Then copper sulfide was formed through sulfidation precipitation with a molar ratio of sulfide agent/copper at 0.7; the grade of copper in the recovered material was 57.55%. This indicates that the product was pure CuS, and filtration resistance could be reduced to promote improved copper recovery. © 2011 American Institute of Chemical Engineers Environ Prog, 2011