METHOD OF PREPARING HYDROXYETHYLIDENE DIPHOSPHONIC ACID FROM PHOSPHORUS- CONTAINING WASTE OF HIGHER FATTY ACID CHLORIDE PRODUCTION Russian patent published in 2001 - IPC

FIELD: heat power industry, oil and textile industries, domestic chemistry, medicine and manufacture of mineral fertilizers. SUBSTANCE: described is method of preparing hydroxyethylene diphosphonic acid from phosphorus containing waste of higher fatty acid chloride production, pretreating it with water to remove organic impurities, followed by acylation with acetic anhydride and aqueous hydrolysis of the resulting acetoxyethylidene diphosphonic acid during heating operation. Treatment is carried out with water in amount of 20- 30 % of weight of waste, followed by maintaining the whole at 60-75 C for 1.5-2.5 hours, separating organic layer of fatty acids, treating residue with phosphorus trichloride at stoichiometric ratio with respect to residual water and blowing dissolved hydrogen chloride from reaction mixture at the same temperature. EFFECT: simplified process, smaller production waste and higher yield of the desired product. 6 ex