METHOD FOR SEPARATE RECOVERY OF SELENIUM AND MERCURY FROM RAW MATERIALS CONTAINING THEM

摘要

1449704 Recovery of selenium and mercury OUTOKUMPU OY 15 Feb 1974 [16 Feb 1973] 7029/74 Heading C1A Selenium and mercury are separately recovered from a material containing both by heating the material in an oxygen-containing atmosphere in admixture with. a basic alkaline earth metal compound, present in a proportion to provide a mole-ratio of alkaline-earth metal to selenium of at least 1 : 1, at a temperature not exceeding 1000‹ C., so that mercury is distilled off and selenium is converted into an alkaline earth metal selenite, and treating the residue with aqueous acid to produce a seleniferous solution, from which the selenium can be recovered by reduction by conventional methods. Suitable alkaline earth metal compounds include calcium and magnesium carbonates, calcite, dolomite, calcium oxide and calcium hydroxide; and the aqueous acid is preferably sulphuric acid.