Abstract: Copper is separated from nickel present therewith in a sulfate solution by neutralizing to precipitate all the copper and some nickel as basic compounds, and thereafter reducing the copper in the basic compounds to elemental form through formation of cuprous sulfite and thermal dissociation of the latter.

Abstract: Sulfur-containing nickel is electrodeposited from a chloride electrolyte in a cell wherein each cathode is separated from any adjacent anode by a pair of diaphragms.

Abstract: An electrolyte containing an organic buffering agent is used to electrowin nickel with a comparatively high bite in a diaphragm-free cell.

Abstract: Sulfate solutions containing at least one valuable metal from the group: Fe, Ni and Co, particularly solutions resulting from the leaching of lateritic ores or concentrates, are treated to recover the valuable metal. The latter is precipitated by treating the solution with magnesium hydroxide. The resulting magnesium-containing solution is treated with lime under controlled conditions to precipitate relatively fine particles of magnesium hydroxide and relatively coarse particles of gypsum. The difference in particle size is relied on to separate the magnesium hydroxide (for recycling) from the gypsum (which is calcined to regenerate lime).

Abstract: Nickel black is prepared by treating a nickeliferous solution with base to precipitate nickel as a basic nickelous precipitate and oxidizing the precipitated nickel with the aid of a mixture containing oxygen and a reducing agent.