METHOD FOR PRODUCTION OF HYDROXYL APATITE Russian patent published in 1997 - IPC

FIELD: chemistry of phosphorous-containing calcium compounds; production of medicinal material for stomatology; production of adsorbent and catalyst. SUBSTANCE: method involves purification of origin concentrated solutions of calcium nitrate (which takes place with the help of activated coal) and ammonium hydrophosphate (which takes place by passing through cationite). Then thus purified solutions of calcium nitrate and ammonium hydrophosphate are alkalized to pH 12.0-12.5 and 10.5-11.5, respectively, the process is carried out with the help of concentrated ammonia. The process is followed by boiling thus obtained suspension within 30-90 min. EFFECT: improved quality. 2 tbl