Influence of minor oxides on formation and decomposition of mineral calcium sulfoaluminate (3CaO·3Al₂O₃·CaSO₄)

Abstract

AbstractAbstractResearch was done on the influence of minor oxide Fe2O3, Cr2O3, ZnO, TiO2 and CaF2 on the formation and decomposition of 3CaO·3Al2O3·CaSO4. The result showed that 3CaO·3Al2O3·CaSO4 began to form at about 1000°C, increased at approximately 1200°C, and then became almost pure 3CaO·3Al2O3·CaSO4—along with the vanishing of the transitional resultant at around 1300°C. CaF2 and Fe2O3 promoted the formation of 3CaO·3Al2O3·CaSO4 and the decomposition of CaSO4 while TiO2, ZnO and Cr2O3 restrained the forming rate of 3CaO·3Al2O3·CaSO4 because of their stabilisation effect on the transitional resultant CA. At 1400°C, 3CaO·3Al2O3·CaSO4 has already decomposed, and adding Cr2O3, ZnO and CaF2 facilitated the process. In addition, Cr2O3 and Fe2O3 decreased the decomposition temperature of 3CaO·3Al2O3·CaSO4.Keywords: 3CAO.3AL2O3.CASO4MINOR OXIDESBURNING TEMPERATUREMINERAL FORMATIONDECOMPOSITION