Device and method for reducing nickel content in cobalt residue produced by chlorine cobalt-removal

The invention discloses a method for reducing nickel content in cobalt residue produced by chlorine cobalt-removal, and belongs to the technical field of hydrometallurgy. A device comprises a cobalt pre-liquid storage tank, a pre-cobalt-removal pipeline, a cobalt-removal reaction pipeline, a cobalt-removal reaction tank set, a cobalt post-liquid filter, a cobalt residue slurrying tank, a filter press and a cobalt residue filter-pressing washing liquor storage tank which are connected in sequence; the method comprises the steps that a copper-removal post-liquid and nickel carbonate are mixed and subjected to pH value adjustment and then react with chlorine, and sodium carbonate is added to adjust a pH value after the pH value and the electric potential of the cobalt-removal reaction tank are controlled; the residue obtained by filtering is slurried by water, and the slurried residue is subjected to warming washing to obtain a slurried liquid; and the slurried liquid is subjected to filter-pressing and blowing,