This disclosure relates to a method for the preparation of calcium monohydrogen phosphate comprising an etching in an aqueous medium, during a predetermined time period, a source of phosphate with an acid with formation of a pulp comprising an aqueous phase containing calcium phosphate in solution and a solid phase containing impurities, a first separation between said aqueous phase and said solid phase, during a predetermined time period, a neutralization of said aqueous phase at a sufficient pH to obtain a precipitation of said calcium monohydrogen phosphate, a second separation between said aqueous medium and said calcium monohydrogen phosphate, characterized in that said predetermined time period of said step a) of digestion is greater than that of said step b).
