| 摘要 |
<p>1439100 Nickel recovery SHERRITT GORDON MINES Ltd 14 June 1974 [5 July 1973] 26392/74 Heading C1A Nickel is recovered in elemental form from a nickel-containing aqueous ammoniacal ammonium carbonate solution by a process which comprises: adjusting the composition of the solution so that it contains at least 1À5 moles of ammonium sulphate per mole of contained nickel; heating the so-adjusted solution to expel carbon dioxide and ammonia and produce a nickel diammine sulphate solution; recovering elemental nickel from said nickel diammine sulphate solution (e.g. by reduction with hydrogen), so forming at least one mole of ammonium sulphate in the end solution per mole of recovered nickel; and recycling the end solution to supply at least a part of the sulphate requirement of the composition adjustment step. Various modifications of the process are described which include steps for the elimination of impurities; e.g. iron, manganese and aluminium may be converted to their hydroxides and carbonates in an oxidative step which also converts sulphur-containing impurities to sulphate ion; copper and cobalt may be precipitated as their sulphides; and build-up of chloride ion in the solution may be prevented by further heating of the nickel diammine sulphate solution until nickel ammonium sulphate is precipitated, followed by separation of the precipitate from the chloride-contaminated solution and dissolution of the precipitate in anammonical solution to form a nickel diammine sulphate solution, which may then be reduced with hydrogen.</p> |
