Experimental and theoretical research on the thermal properties of carbonate mixtures

Abstract

In this paper, Na2CO3, Li2CO3 and K2CO3 were selected to prepare carbonate mixtures according to different proportions. The thermal property and stability of the samples were tested by differential scanning calorimeter (DSC). The phase change temperature and latent heat of carbonate mixtures were calculated by theoretical formula, and compared with the experimental data to verify whether the theoretical formula are applicable in the field of high temperature molten salt. The results show that the melting point of carbonates which melted together is about 400°C. And the melting point of ternary carbonates is lower than the single component. The initial crystallization points of some samples are higher than the melting points. The differences between the melting point and the primary crystallization temperature are 5∼20°C. The phase change latent heat of the carbonate mixtures is lower than the single component’s. The latent heat of melting is more than the latent heat of solidifying. The DSC testing curves of the carbonate mixtures are almost coincident. The stability of mixed carbonate is very good. This experiment will provide reference and basis for its application in solar thermal power generation.