REMOVAL OF SELENIUM FROM ACIDIC COPPER/NICKEL SOLUTIONS

摘要

Selenium (IV) and selenium (VI) are removed from acidic copper-nickel sulphate solutions in a two-stage process by adjusting and maintaining the sulphuric acid content of the solution in a range of 10 to 50 g/L and, in a first stage, contacting the solution with sulphur dioxide or a sulphite-containing solution at an elevated temperature in the range of about 140.degree. to 175.degree.C and, in a second stage, maintaining the said solution at an elevated temperature in the range of about 140.degree. to 200.degree.C and pressure within the range of about 400 to 1750 kPa in an essentially oxygen-free atmosphere for a sufficient retention time to reduce and precipitate selenium (VI) as cuprous selenide.