Ceramic Materials in Na2O-CaO-P2O5 System, Obtained via Heat Treatment of Cement-Salt Stone Based on Powder Mixture of Ca3(C6H5O7)2 ∙ 4H2O, Ca(H2PO4)2 ∙ H2O and NaH2PO4

Ceramic materials in Na2O-CaO-P2O5 system were obtained by firing cement-salt stone made from pastes based on powder mixtures including calcium citrate tetrahydrate Ca3(C6H5O7)2 ∙ 4H2O, monocalcium phosphate monohydrate (MCPM) Ca(H2PO4)2 ∙ H2O and/or sodium dihydrogen phosphate NaH2PO4. The phase composition of the obtained samples of cement-salt stone after adding water, hardening and drying included brushite CaHPO4 ∙ 2H2O, monetite CaHPO4 and also unreacted Ca3(C6H5O7)2 ∙ 4H2O, Ca(H2PO4)2 ∙ H2O and/or NaH2PO4. The phase composition of ceramics in Na2O-CaO-P2O5 system obtained by firing cement-salt stone was formed due to thermal conversion of hydrated salt and heterophase reactions between components presented in samples during firing. The phase composition of ceramic samples based on powder mixture of Ca3(C6H5O7)2 ∙ 4H2O and Ca(H2PO4)2 ∙ H2O after firing at 900 °C included β-calcium pyrophosphate (CPP) β-Ca2P2O7. The phase composition of ceramic samples based on powder mixture of Ca3(C6H5O7)2 ∙ 4H2O, and NaH2PO4 after firing at 900 °C included β-sodium rhenanite β-CaNaPO4. The phase composition of ceramic samples based on powder mixture of Ca3(C6H5O7)2 ∙ 4H2O, Ca(H2PO4)2 ∙H2O and NaH2PO4 after firing at 900 °C included β-Ca2P2O7, β-CaNaPO4, double calcium-sodium pyrophosphate Na2CaP2O7, and Na-substituted tricalcium phosphate Сa10Na(PO4)7. Obtained ceramic materials in Na2O-CaO-P2O5 system including biocompatible and biodegradable phases could be important for treatments of bone tissue defects by means of approaches of regenerative medicine.