Extraction of germanium from acidic leach solutions by liquid membrane technique

Abstract

 Precipitates from a zinc plant (CINKUR Co., Turkiye) electrolyte purification section consist an average of 1200 ppm germanium, 10% copper, 15% zinc, 2.5% cadmium, 0.2% cobalt, and 8% iron. The precipitate or "copper" cake has been leached with sulphuric acid, and thus acidic leach liquors are obtained. The application of emulsion liquid membrane technique to the extraction of germanium from the acidic leach liquors is examined. The important variables governing the permeation of germanium through liquid membranes and their effects on the separation process are studied. These variables are the membrane type and composition, surfactant type and composition, carrier composition, pH, and various additives or modifiers. The carrier or the extractant used is an alkylated hydroxyquinoline, Kelex 100 that is manufactured by Schering Berlin AG, Germany. Under the suitable conditions it is possible to selectively extract 95% of germanium from the acidic leach solutions, containing Cu, Zn, Cd, Co and Fe ions, using the carrier Kelex 100.

The authors wish to express their sincere gratitude to Exxon Chemical Co., U.K. and Belgium, for supplying the surfactant ECA 4360J, the solvents STA90 NS and Escaid 110.