The invention discloses a method for removing iron, aluminum and
silicon from a
nickel-
cobalt-
manganese-
copper solution under normal pressure. The method comprises the following steps that 1) a rough
nickel-
cobalt-
manganese-
copper raw material is taken and mixed with water to form
slurry, then acid and a
reducing agent are added for leaching, the pH value at the leaching end point is smaller than or equal to 2.5, and the Fe<2+> content is controlled to be proper; (2) after the leaching
slurry is subjected to dense separation, supernate and a precipitator are added, in a parallel flow mode, into liquid which contains
nickel,
cobalt,
manganese and
copper without iron, aluminum and
silicon at the temperature of 70-100 DEG C, and heat preservation is conducted, wherein the precipitator is a rough nickel-cobalt-manganese-copper
raw material with the
solid content being 1-50%, and the pH value of the liquid without iron, aluminum and
silicon ranges from 3.0 to 4.0; and 3) the
slurry is subjected to
solid-liquid separation, filtrate is as an extraction
stock solution, water is added into removed iron-aluminum-silicon
slag and leaching
slag to prepare slurry with the
solid content being smaller than or equal to 50%, acid is added to regulate the pH value to 2.0-3.5, a
reducing agent is added to enable the Fe<2+> concentration to be greater than or equal to 0.1g / L, the removed iron-aluminum-silicon
slag and the filtrate are obtained after solid-liquid separation, and the filtrate is fed to a leaching section for leaching raw materials. According to the method, auxiliary materials and hazardous chemicals do not need to be used for removing iron, aluminum and silicon, other elements are not introduced either, the purposes of lowering the cost of the auxiliary materials and the
salinity of
wastewater are achieved, and the
sewage treatment pressure is lowered.