Process for manufacturing finely divided, hardly soluble salts of oxyacids of phosphorus

摘要

In the process for producing a finely dispersed, sparingly soluble salt of an oxygen acid of phosphorus with a grain size of at most 20 μm by reacting a compound of a divalent metal with the oxygen acid of phosphorus or one of its alkali metal or ammonium salts, the grain size distribution of the finely dispersed salt is achieved by at least 90% between 0.05 and 7 µm an at least 5% by weight aqueous solution or suspension of a compound of a divalent metal from the group Mg, Ca, Sr, Ba, Mn, Zn, Cu, Cd, Pb, Sn, Co, Ni while maintaining a pH range between 3 and 9 with an at least 2 mol% solution of at least one trivalent metal from the group Al, Fe, Cr in the oxygen acid of phosphorus and optionally with an aqueous solution of an alkali metal or ammonium salt of oxygen acid Phosphorus with reaction to the reaction, separates the precipitated salt and dries it.