Recovery of Copper from Heavy Metal Containing Sludge with Jarosite and Oxidation Processes

摘要

The aim of this study was to develop an effective process to recover copper from the heavy metal containing sludge. The sludge was first leached by sulfuric acid, the K_2SO_4 was then added in the leaching solution for jarosite formation with mole ratio of K/Fe 1/3～3. The pH-value of leaching solution was adjusted to 1～2 by adding CuO. The formation of jarosite was followed at 70-90℃. When the jarosite process was accomplished, the solid product was KFe_3(SO_4)_2(OH)_6 precipitation. The copper ion remained in the solution. The pH-value of solution was adjusted to 11 with NaOH, and the aeration operation for oxidation was followed at 70-90℃. When the oxidation process was accomplished, the main product was CuO. The valuable copper compound could be refined in the copper metallurgy and the jarosite could be used as dyes or as coagulant for waste-water treatments.