Continuous pure hydroxy:apatite prodn - by reaction phosphate and calcium salt solns at controlled pH

摘要

Continuous hydroxyapatite prodn., from aq. phosphate and calcium salt solns., involves continuously forming a mixt. of the solns., while regulating the reaction medium pH at 6-7. Appts. comprises a heated reactor (1); a device (5b) for regulating the reactor heater (4) according to the temp. measured by a temp. measuring device (5a); a stirrer (2,3); feed systems for controlled supply of the phosphate and calcium salt solns., into the central reactor zone; a base injection system (15-17); a pH measuring device (18a) coupled to a controller (18b) for controlling base injection; a vapour condenser (19); an overflow collector (20) at the upper part of the reactor for controlled product withdrawal; and a filter (21) for solid phase sepn. from the withdrawn prod. USE/ADVANTAGE - The hydroxyapatite is useful for biological applications. The process allows continuous, reproducible prodn. of pure hydroxy-apatite of (near) stoichiometric compsn., Ca10(PO4)6(OH)2, and with reproducible properties (esp. particle size and porosity) which can be adjusted according to the application.