GB505111A - Improvements in or relating to the recovery of metals from their amalgams - Google Patents

Abstract

505,111. Extracting metals. DU PONT DE NEMOURS & CO., E. I. Nov. 4, 1937, No. 30298. Convention date, Nov. 4, 1936. [Class 82 (i)] Metals,.e.g. aluminium, beryllium, cadmium, calcium, barium, strontium, magnesium, copper, tin, sodium, potassium, and zinc are recovered from dilute liquid metal amalgams by cooling the latter to a temperature sufficiently low to precipitate a solid concentrated amalgam which is separated from the liquid mercury. The concentrated amalgam may be used as a reducing agent, may be decomposed by heat, and/or, in the case of amalgams of alkalimetals, by treatment with substances such as magnesium or alkaline-earth metals as described in Specification 505,097, the mixture being preferably rendered liquid by the addition of molten alkali metal, and the alkaline earth or other treating metal being recovered for further use by distillation of the mercury. The dilute amalgam may be produced by the electrolysis of a metallic salt using a cathode of mercury as in Specification 491,879, [Group III], or of an amalgam which may be such as to provide a dilute mixed amalgam. The electrolysis may be carried out at a temperature of 60-80‹ C. or at higher temperatures produced by operating the cell under pressure. The amalgam so produced may be cooled to 10-30‹ C. and the separation of the concentrated amalgam is effected by filtration followed by pressing, the mercury being returned for use as a cathode.