Method for preparing lithium iron phosphate precursor from high-iron red mud

The invention relates to a method for preparing a lithium iron phosphate precursor from high-iron red mud, and belongs to the technical field of comprehensive utilization of industrial solid wastes. The method comprises the steps that the high-iron red mud and acid liquor are mixed and then leached, and red mud leachate is obtained; mixing the red mud leachate with phosphate, and then carrying out first homogeneous reaction to obtain a primary homogeneous solution; adjusting the pH value and the iron-phosphorus ratio of the primary homogeneous solution, and then carrying out a second homogeneous reaction to obtain a secondary homogeneous solution; separating out the secondary homogeneous solution to obtain a lithium iron phosphate precursor; according to the method, the iron phosphate dihydrate is separated out through the characteristics of various substances of phosphate, exogenous substances such as an extracting agent, an inducer, a separating agent and a metal capturing agent are not added, additional co