Removal of Copper from Acidic Nickel Chloride Solution with Nickel Matte.

Removal of copper from acidic nickel chloride solution was investigated using nickel matte with different compositions in various conditions. The following results were obtained.1) Cupric ion in the solution is reduced to cuprous ion by metallic nickel or Ni3S2 in matte at the early stage after addition of nickel matte into the solution. Consequently metallic copper or copper sulfide; Cu2S is formed by the reaction with the matte.2) Copper is removed as metallic copper when the solution is reduced to below-50 mV of oxidationreduction potential, while as Cu2S above 150mV.3) These types of copper removed from the solution change according to the R value, defined as ratio of content of metallic nickel and Ni3S2 to amount of copper ion in the solution.4) The reaction for metallic copper formation is faster than that for the formation of Cu2S. The difference between the reaction constants for both reactions at 75°C, is approximately ten times.5) Copper is removed to a lower concentration with addition of both matte and elemental sulfur.