Hydrometallurgical recovery method for nickel sulfate

A hydrometallurgical nickel sulfate recovery method comprising:

• a washing step of washing a raw material containing nickel (Ni), cobalt (Co), and manganese (Mn) with washing water, wherein the raw material and the washing water are in a volume ratio in a range of 1:1 to 5 in the washing step;
• a first solid-liquid separation step of separating the washed raw material into a raw material cake and a filtrate;
• a first leaching step of adding sulfuric acid to the raw material cake for reaction, wherein in the first leaching step, an equivalent ratio of a metal in the raw material cake and the sulfuric acid is in a range of 1:0.5 to 2;
• a second leaching step of adding hydrogen peroxide to a first leachate obtained through the first leaching step for reaction, wherein in the second leaching step, an equivalent ratio of metal components, including manganese and cobalt, in the first leachate to the hydrogen peroxide is in a range of 1:0.5 to 2;
• an iron precipitation step of adding hydrogen peroxide and nickel hydroxide (Ni(OH)2) to a leachate formed through the first and second leaching steps for iron precipitation, wherein in the iron precipitation step, an equivalent ratio of iron in the leachate to the hydrogen peroxide is in a range of 1:0.5 to 3;
• a second solid-liquid separation step of separating reaction products of the iron precipitation step into a precipitate containing iron and a leachate containing nickel, cobalt, and manganese;
• a solvent extraction step of extracting a nickel sulfate aqueous solution (NiSO4) from the leachate;
• and
• a nickel hydroxide preparation step of preparing nickel hydroxide (Ni(OH)2) from nickel-bearing liquid waste obtained through the solvent extraction step,
• wherein the nickel hydroxide prepared through the nickel hydroxide preparation step is used in the iron precipitation step.