Study on the extraction of nickel and copper from low ice nickel matte in ferric chloride solution

The oxidation of trivalent iron ions was utilized to extract nickel and copper from a low ice nickel matte in ferric chloride solution. In this study, the effects of the liquid-solid ratio, leaching temperature, leaching time and ferric chloride solution concentration on the leaching rates of nickel and copper were investigated by single-factor tests and orthogonal experiments. The kinetic study shows that the leaching process of nickel in ferric chloride solution is controlled by a chemical reaction, while the leaching process of copper is controlled by mixing. The calculated leaching activation energies of nickel and copper are 70.26 kJ/mol and 38.62 kJ/mol, respectively. In addition, the phase analysis of low-ice nickel and leaching residue shows that the sulfur element in low-ice nickel is oxidized to elemental sulfur when the leaching reaction occurs. Furthermore, the problem of sulfur-containing gas pollution in traditional processes is avoided.