Preparation and properties of self-pulverizing calcium sulfoaluminate cement

The transition of beta-C2S to gamma-C2S can be used to pulverize cement clinkers for saving grinding energy because the volume expansion occurs in this process. Self-pulverizing calcium sulfoaluminate cement (SPCSA) was prepared and optimized through controlling the polymorphic transition. The influences of preparing technologies and compositions on pulverization were investigated. Quantitative XRD was conducted to define phase compositions of clinkers, and sieve analysis was used to evaluate the pulverization degree. Mechanical properties and grinding energy consumption of SPCSA were tested and compared with ordinary calcium sulfoaluminate cement (CSA). The results show that the pulverization degree and properties of SPCSA are influenced by sintering temperature, cooling rate, chemical impurities and mineral compositions. The appropriate sintering temperature is 1280-1350 degrees C, and the cooling rate should not exceed 500 degrees C/min. Meanwhile, the optimal mineral compositions of SPCSA are proposed. The grinding test reveals that SPCSA can save grinding energy by 60-75% in comparison with stabilized CSA. (C) 2012 Elsevier Ltd. All rights reserved.