FEASIBILITY OF COPPER LEACHING FROM AN INDUSTRIAL SLUDGE USING AMMONIA SOLUTIONS

Feasibility study on the recovery of copper from an industrial sludge was conducted. The petrochemical sludge containing high concentration of copper was characterized utilizing X-ray diffractometer (XRD) and X -ray photoelectron spectroscopy (ESCA), Sequential extraction was used to determine the chemical forms of copper in the sludge. To leach cop per from the sludge, aqueous ammonia solution was used. The leaching r eaction was completed within 6 h. Best leaching efficiency (ca, 94%) w as found at pH of 10, Higher solid-liquid ratio and higher temperature could enhance the leaching reaction. Results of the copper speciation s in the leached sludge show that copper was mainly leached from both the organic-bound and residual fractions. Results suggested that the a mmonia-leaching technique is full of potential in metal recovery from industrial sludges. (C) 1998 Elsevier Science B.V.