METHOD FOR PRODUCING HYDROXYAPATITE Russian patent published in 1997 - IPC

FIELD: inorganic chemistry, production of hydroxyapatite used in medicine and in gas-liquid chromatography as filler or sorbent. SUBSTANCE: method comprises following steps: mixing calcium hydroxide suspension with aqueous solution of phosphoric acid. Reaction mixture is caused to pass through two successively arranged zones. In first zone pH = 10.0-11.0 is maintained, process flow rate being 0.8-1.5 m/s. In second zone suspension is subjected to 400-500-fold dilution and recycled to first zone, thereby causing reaction mixture to circulate 4-5 times in closed-loop cycle for 10-20 minutes. product is separated by filtering, followed by drying. EFFECT: higher yield of higher-quality hydroxyapatite, better phase composition purity. 3 cl, 2 dwg, 1 tbl