FOERFARANDE FOER BEHANDLING AV MOLYBDENHALTIGA NICKEL JAERN OCH SVAVEL INNEHAOLLANDE METALLSTENAR MELLANPRODUKTER OCH RESTER

1319503 Removal of Mo from Ni-containing residues SHERRITT GORDON MINES Ltd 16 Nov 1970 [7 Jan 1970 18 Sept 1970] 54459/70 Heading C1A Molybdenum is removed from residues containing Ni, Fe and S and possibly Cu, Co, Cr or W by mixing with the latter, before and/or during pelletizing of the same using water, an alkali in an amount equivalent to a residue-to- NaOH weight ratio of from 20 : 1 to 3 : 1; roasting the pellets at 540‹-870‹C. with a source of oxygen (e.g. air or steam) present to convert substantially all of the Mo into watersoluble alkali metal molybdates; quenching the roasted, pelletized mixture in water and agitating the slurry to extract and dissolve the molybdates; and finally separating the solution from the Ni-containing residue. Tungsten, if present in the original residue, may also be removed as water-soluble tungstates. The alkali to be used is preferably NaOH, KOH, Na 2 CO 3 , K 2 CO 3 or Na 2 S or mixtures of these.