Formation of Ca₃SiO₅ prepared by electric and microwave burning

A new method of sintering Ca₃SiO₅ by the combination of conventional and microwave heating methods was studied. The influence of transitional metal oxides such as Fe₂O₃, Cr₂O₃, MnO₂, and V₂O₅ used as the additive of microwave absorption on the microwave-promoted burning of Ca₃SiO₅ was investigated. The experimental results indicate that the new burning technique is capable of promoting the sintering of Ca₃SiO₅. At 1200-1300℃ in an electric furnace, Ca₃SiO₅ can be obtained only when the sample is heated in a microwave for 110-240 s, and the free lime content is below 40wt%. Based on the experiments, Fe₂O₃, Cr₂O₃, MnO₂, and V₂O₅ can enhance microwave sintering. Amongst them, Cr₂O₃ is the most effective. The characteristic of the X-ray diffraction peaks of Ca₃SiO₅ is similar to those of standard Ca₃SiO₅, but the peaks are wider.