Research of the lime rich portions of the CaO-SiO2-P2O5 system

Abstract

A detailed study has been carried out to explain the influence of Pp^ in silicate phases and in industrial raw meals upon their mineralogical compositions. Some compositions in the lime rich portion of the CaO-SiO₂-P₂O₅ system are studied using laboratory reactants. The results showed that the compositions lying in the range of CaO = 69,5-70,1; P₂O₅= 16,2-19,5; SiO₂ = 11,1-13,6 (wt%) give, at 1000 °C, the mineralogical composition (HAp, β-C₂S, C₅PS) which can develop a high strength in chemically bonded ceramics. At high temperature (1400 ºC) these compositions give a large amount of silicocarnotite (C₅PS) and 2C₂.C₃P phase. A selected composition of the industrial raw meal with added phosphate: CaO = 62,66; SiO₂ -= 17,33; Al₂O₃ = 4,88; Fe₂O₃ = 4,29; P₂O5 = 8,73; MgO = 2,09 (wt%) forms at 1350 ºC a clinker containing high amount of α-C₂S to replace C₃S. Such a clinker may have good applications in the synthesis of active belite cement.