Study of phase transformation of calcium silicate using desert sand as raw materials.

Production of Portland cement consumes a huge amount of silica mineral. The present work aims to introduce desert sand to replace the natural mineral to achieve green manufacturing of silicate cement clinker, as well as further decreasing the synthesis temperature and increasing the production efficiency. The effects of desert sand, industrial quartz and high‐purity quartz as raw materials, and Al2O3 and Fe2O3 as additives on phase transformation and microstructure of calcium silicate powder were comparably investigated using X‐ray diffractometer, differential scanning calorimeter, and scanning electron microscopy. Results show that the main phases of all samples with different raw materials and additives were 3CaO·SiO2 (C3S) and 2CaO·SiO2 (C2S). In which, the samples prepared using desert sand had the lowest phase transformation temperature for C2S and C3S. When adding Al2O3 and Fe2O3, the phase transformation temperatures of C2S and C3S further decreased, which were 1032.5°C and 1270.9°C, respectively, meanwhile phase content reached the maximum (C2S of 65.6 wt.% and C3S of 61.2 wt.%). In addition, the most uniformly and finely distributed crystalline phases formed at an optimal calcination temperature of 1350°C. This is beneficial for reducing production costs, saving mineral resources, and promoting the sustainable development of the cement industry. [ABSTRACT FROM AUTHOR]