METHOD FOR PRODUCTION OF ANTICORROSION PIGMENT ON BASE OF ALUMINIUM TRIPHOSPHATE Russian patent published in 1998 - IPC

FIELD: protection of various metals and alloys against corrosion. SUBSTANCE: anticorrosion pigment on the base of aluminium phosphate is prepared according to simplified scheme. Initially dissolution of aluminium hydroxide is carried out at 60-100 C, the process takes place by feeding ortophosphoric acid with room temperature into suspension of aluminium hydroxide having concentration 180-200 g/dm³ (as calculated for dry Al(OH)₃). Then aluminium pripolyphosphate is precipitated from thus prepared solution, the process is carried out by feeding lime milk with concentration 60-90 g/dm³ (as calculated for CaO) into the same apparatus. The process takes place at room temperature till pH of precipitation is 4.5-6.6. Then mixing within 30 min, filtration and drying of finished product are carried out. EFFECT: improved efficiency. 2 cl, 1 tbl