Preliminary laboratory work done under a Memorandum of Agreement between the Bureau of Mines Rolla Research Center and the Harrison Radiator Div., General Motors, Corp., has indicated that zinc can be recovered from wastewater treatment sludges generated at the harrison plant at Lockport, New York the method developed at the Rolla Research Center, Rolla, Missouri, for extracting zinc from the sludge involves roasting, leaching-purification, and electrowinning. Roasting to combust the organic fraction and leaching with h2so4 to stabilize the zinc proceeded routinely. Purification and electrowinning followed standard practice for a commercial zinc electrowinning plant, but because of the large amounts of delecterious impurities coextracted with the zinc, as much as 50 times greater than normally encountered in a commercial operation, an extensive modification of the purification procedure was necessary. Zinc was electrowon with good current efficiency and deposit morphology. Residues are being characterized to determine the feasibility of recovering valuable constituents prior to disposal in an environmentally acceptable manner.
Res. and Conservation, V.6, No. 3-4, November 1981, PP. 203-210