Method for separating vanadium and nickel

The invention provides a method for separating vanadium and nickel, which comprises the following steps: (1) mixing and filtering a solid material containing vanadium and nickel and reducing organic acid to obtain a nickel-containing complex precipitate and a vanadium-containing complex solution; (2) inorganic acid and the vanadium-containing complex solution obtained in the step (1) are mixed, cooled, crystallized, centrifuged and filtered, and a vanadium-containing solution and reducing organic acid are obtained; the reducing organic acid in the step (1) comprises any one or a combination of at least two of formic acid, citric acid, glyoxylic acid or oxalic acid. According to the method, the phenomenon of mutual entrainment caused by combination of vanadate and nickel ions during separation can be avoided, vanadium enters a solution in a vanadium complex form, nickel enters a slag phase in a nickel complex precipitation form, deep separation of vanadium and nickel is promoted, meanwhile, cyclic utilization