The invention discloses a method for producing
lithium dihydrogen
phosphate by using a low-
lithium-concentration strong-basicity
lithium-containing leaching solution, and relates to the technical field of lithium salt production. The method specifically comprises the following steps: adding a
sodium phosphate or
sodium hydrogen phosphate solution into the lithium-containing leaching solution, reacting to obtain
slurry, carrying out
solid-liquid separation, washing the obtained
filter cake, adding water, slurrying, adding
phosphoric acid, completely dissolving to obtain a solution, adding a precipitant into the solution, adjusting the pH value to alkalescence, precipitating, and
drying to obtain the lithium-containing leaching solution. And carrying out
solid-liquid separation on the obtained precipitate, washing the obtained
filter cake, adding water for slurrying, adding
phosphoric acid, continuously stirring for reaction, completely dissolving to obtain a clear lithium dihydrogen phosphate solution, and treating to obtain the battery-grade lithium dihydrogen phosphate. According to the method, efficient extraction of lithium is successfully realized, a lithium dihydrogen
phosphate product with a high additional value is generated, a large amount of acid consumption in the alkali liquor
neutralization process is avoided, the consumption of alkali in the solution is relatively low, and the solution can be returned to the previous procedure for cyclic utilization.