Method for extracting and separating copper, chromium and nickel from acid leaching solution

The invention discloses a method for extracting and separating copper, chromium and nickel from an acid leaching solution, and relates to a method for separating copper, chromium and nickel from the acid leaching solution containing copper, chromium and nickel resources during a hydrometallurgy process. The technological process of the method comprises the following steps in sequence: (1) adding an extraction agent to the acid leaching solution to extract copper; (2) adding sulfuric acid to an organic phase with copper extracted to separate the copper by reverse extraction; (3) After a raffinate phase with copper extracted is unoiled, adding soluble phosphate to perform chromium sinking reaction by phosphoric acid; and (4) performing filtering separation to obtain chromic phosphate and chromic hydroxide compound precipitate and nickeliferous filtrate. The method provided by the invention is simple in technological operation, is short in flow and low in cost, has strong selectivity in a wider metal ion concentration range, achieve an ideal separating effect in copper, chromium and nickel, and has a remarkable economic benefit as copper recovery rate is greater than 99% and recovery rates of both chromium and nickel are greater than 98%; and moreover, the phosphate precipitator is recyclable and the production process is free of secondary pollution.