Concentrates obtd. from low grade nickel oxide ores - by roasting ore with coke, aluminium and potassium chloride

摘要

The ore is treated with 0.5-3% of its wt. of a reducing agent (a) consisting of Al, Mg, and/or a carbonaceous material (a1) contg. sulphur cpds. or salts of metals in gp. VIII of the periodic system; and a chlorination agent (b) is also added. The resulting mixt. is roasted 0.5-1.5 h at 800-950 degrees C. to obtain a residue from which a concentrate contg. Ni or Ni plus Co is obtd. Material (a1) is pref. coke used in a wt. ratio coke: Ni in the ore of between 0.05:1 and 0.14:1; and the coke may be replaced by, or mixed with a waste alcoholic sulphite lye. Agent (b) is pref. 5% KCl w.r.t. the wt. of the initial ore. The low grade ores pref. contain less than 1% nickel. Increased yields of Ni or Ni plus Co in the concentrates.