METHOD FOR PRODUCING NANOHYDROXYAPATITE Russian patent published in 2017 - IPC C01B25/32 C01F11/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: method for producing nanohydroxyapatite comprises mixing in the reactor the four-watered calcium nitrate solution of Ca(NO₃)₂⋅4H₂O with the concentration of 0.01-0.15 mol/l with the aqueous solution of orthophosphoric acid H₃PO₄ with the concentration of 1.4-1.5 mol/l at a molar ratio of Ca/P=5/3, thermostating the resulting solutions mixture under constant stirring with a stirrer rotating at the speed of 170-200 rev/min, until reaching the temperature equilibrium with the external thermostatic jacket heated to the temperature of 33-37°C, adding sodium hydroxide solution NaOH with a concentration of 1 mol/l, heated to 37-42°C, until reaching the acidity index of pH=7, maintaining the molar ratio of Ca/Na=1.25-1.30. Moreover, 2/3 of the sodium hydroxide solution is added directly to the reactor center at a flow rate of 7-10 m/s, the remaining amount - with portions of 50 ml, and then the resulting sol is maintained at a temperature of 37°C and the stirrer switched off for one hour, removed from the reactor, centrifuged and washed three times with bidistilled water.

EFFECT: simplifying the production and reducing the production time.

2 cl, 4 dwg, 1 tbl, 2 ex