METHOD OF PREPARING INHIBITOR OF MINERAL SALT DEPOSITS Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: method comprises reacting ammonia derivatives, including ammonium chloride or polyethylene polyamine production waste, with formaldehyde and phosphorous acid or with trichloride hydrolysis product in dilute hydrochloride acid at elevated temperature and subsequently neutralizing the resulting solution with sodium hydroxide to pH of 6.5- 1.0, process being carried out at molar ratio of original reactants, namely ammonia, formaldehyde and phosphorous acid of 1.0:2.35-2.65; 2.2-2.4. The resulting inhibitor is highly efficient during stabilization treatment of water and has carbonate index of greater than 15 mg.equiv/l, and water at water-stream boiler outlet has temperature of 110-140 C. EFFECT: more efficient preparation method. 6 ex, 3 tbl