Method of obtaining complex acidic salts of divalent metals and dicarboxylic acids

1. A method of obtaining a complex acidic salt of a divalent metal and a dicarboxylic acid, the method comprising:

heating water in a reactor;

adding a dicarboxylic acid to the heated water to produce a suspension of the dicarboxylic acid in the water;

stirring the water to dissolve the dicarboxylic acid in the heated water so as to convert the suspension into a solution of the dicarboxylic acid in the heated water;

during the stirring, and while the suspension is being converted to the solution, adding MeO to the reactor, where Me is a divalent metal, and

wherein a molar ratio of the dicarboxylic acid and the MeO in the heated water is 2.005:1-2.1:1;

continuing the stirring until formation of the complex acidic salt Me(AcH) 2 .nH 2 O begins,

where Ac is an anion of the dicarboxylic acid, and 0<=n<=8;

cooling the complex acidic salt to below a temperature of crystallization of the complex acidic salt;

sedimenting the complex acidic salt;

filtering the complex acidic salt to remove water from the complex acidic salt; and

drying the complex acidic salt.

2. The method of claim 1 , wherein the divalent metal is any of potassium, magnesium and zinc.

3. The method of claim 1 , wherein the dicarboxylic acid is any of L-aspartic acid, L,D-aspartic acid, fumaric acid and amber acid.