The invention discloses a method for preparing precursors of
lithium titanate and
lithium iron phosphate by comprehensively using
ilmenite, which comprises the following steps of: 1) separating the
ilmenite, namely crushing the
ilmenite, leaching the ilmenite with
hydrochloric acid, filtering the ilmenite to obtain a residue and a filtrate; 2) preparing the precursor of the
lithium titanate, namely washing the residue prepared by step 1) with the
hydrochloric acid, adding the washed residue in aqueous alkali, cooking the mixture, filtering the mixture after cooling, and then adding the obtained filter residue in the
hydrochloric acid, cooking the mixture, and filtering, washing,
drying and calcining the mixture after cooling to obtain the precursor of the
lithium titanate; and 3) preparing the precursor of the
lithium iron phosphate, namely taking the filtrate prepared by step 1) as a
raw material, adding
iron powder to reduce
ferric iron, diluting the reduced filtrate, adding a complexing agent and a precipitant into the diluted mixture, controlling the pH value of the
system, reacting the mixture at 30 to 80 DEG C, aging the reacted mixture, and filtering, washing and
drying the obtained precipitate to obtain the precursor of the
lithium iron phosphate. The method is wide in
raw material source, simple in process flow, good and stable in product quality, low in cost and comprehensive and full in use of the ilmenite.