Solvation of ions. Some applications. IV A novel process for the recovery of pure silver from impure silver chloride

Parker, A.J., Clare, B.W. and Smith, R.P. (1979) Solvation of ions. Some applications. IV A novel process for the recovery of pure silver from impure silver chloride. Hydrometallurg, 4 (3). pp. 233-245.

Abstract

Silver chloride is exceptionally soluble in dimethylsulfoxide saturated with calcium chloride at 25°C. Solutions containing up to 196 gl−1 silver as Ca(AgCl2)2 have been prepared. If 30–40% by volume of water is added to such solutions, then pure silver chloride is precipitated almost quantitatively. The silver chloride can be easily converted to pure (99.99%) silver metal either by melting at 1100°C with excess sodium carbonate as flux, or by reducing with hydrogen at 300–400°C, or by reducing an aqueous suspension with zinc dust. The water added to the DMSO solution can be recovered by distillation and both it and the CaCl2-DMSO bottoms are recycled for further leaching. This leads to a fast and cheap process for obtaining silver from crude silver chloride, or from materials containing silver in a form that can be converted to silver chloride. Applications to an anode slimes leach residue, a silver halide teaching laboratory residue, and the silver chloride cake from a gold refinery are demonstrated.

Item Type:	Journal Article
Murdoch Affiliation(s):	School of Mathematical and Physical Sciences
Publisher:	Elsevier BV
Copyright:	© 1979 Elsevier B.V.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/21445

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