METHOD OF PREPARING INHIBITOR OF MINERAL SALT DEPOSITS Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of preparing inhibitor of mineral salt deposits by reacting ammonia derivatives, including ammonium chloride or poluethylene polyamine production waste, with formaldehyde and phosphoric acid as such or phosphorus trichloride hydrolysis product in dilute hydrochloric acid at elevated temperature and subsequently neutralizing the resulting solution with sodium hydroxide to pH of 6.5+1.0. As disclosed in the present invention, process is carried out at molar ratio of initial agents namely ammonia to formaldehyde to phosphorous acid of 1.0: 2.66-2.7: 2.5-2.6. In this case neutralization of the resulting product is carried out using sodium hydroxide powder. In addition neutralization is also carried out using sewage- based solution from anionit filters OH-1. Method makes it possible to prepare inhibitor having better physico-chemical characteristics, namely higher content of main ingredient and higher effectiveness of inhibition both with respect to calcium carbonate and calcium sulfate as compared with the prior art method. EFFECT: more efficient preparation method. 3 cl, 3 ex, 1 tbl