PROCESS FOR THE PRODUCTION OF METALLIC COPPER,SILVER OR MERCURY BY PRECIPITATION FROM AQUEOUS SOLUTIONS OF COMPOUNDS THEREOF

摘要

1325981 Producing copper, silver or mercury YEDA RESEARCH & DEVELOPMENT CO Ltd 7 Jan 1972 [12 Jan 1971] 854/72 Heading C7D Copper, silver or mercury are obtained from aqueous solutions of their salts by contacting the solutions with a reduced anthraquinone in an organic solvent. The process is particularly suited to the precipitation of pure copper, silver or mercury from solutions of their salts contaminated with compounds of other metals. Preferred anthraquinones are those substituted in the 2-position by lower alkyl groups and the solvent system preferably contains both aromatic and polar species, e.g. xylene together with 2-ethylhexanol, although esters such as ethyl acetate can also be used. The reduction of the anthraquinone compound can be effected before or after dissolving in the organic solvent, by hydrogen in the presence of a catalyst. After the precipitation of the required metals, the organic phase can be separated and reduced again for further use. The precipitation is generally carried out by contacting the aqueous solution of the metal salt with repeated batches of the reduced anthraquinone solution, but it is also possible to operate in a continuous manner.