The invention provides a method for preparing aluminum dihydrogen
phosphate and comprehensively recovering
lithium salt from
lithium phosphorus aluminum ore, and relates to the technical field of
metal recovery, the method comprises the following steps: S1, ball-milling the
lithium phosphorus aluminum ore; s2, carrying out
nitric acid pressure leaching to obtain
phosphorus lithium aluminum ore
powder, and carrying out
solid-liquid separation to obtain a leaching solution and leaching residues; s3, adjusting the pH value of the
leachate to obtain an aluminum dihydrogen
phosphate precipitate and a filtrate; s4, deeply removing impurities from the filtrate, adding Na2CO3, and precipitating to obtain Li2CO3 and lithium
precipitation mother liquor; and S5, the lithium
precipitation mother liquor is returned to the step S3 to be used for adjusting the pH of the
leachate. According to the method, after the
lithium phosphate aluminum ore is subjected to ball milling, a
roasting section is omitted, the production cost is saved, valuable elements in the
lithium phosphate aluminum ore are comprehensively recycled, other
impurity ions are not introduced, only
inert substances mainly containing
silicon are contained in leaching residues, the environment
pollution is reduced, meanwhile, the comprehensive economic value of the ore is improved, and the method has the advantages of being short in process
route, low in cost and the like. The extraction rate of valuable elements is high, and the purity of aluminum dihydrogen
phosphate and
lithium carbonate is high.