Preparation and Experimental Study of Mixed Carbonates With High Maximum Using Temperature

In order to meet the demands of future high-temperature solar thermal power generation, 37 kinds of mixed carbonate molten salts were prepared by mixing potassium carbonate, lithium carbonate, sodium carbonate in accordance with different proportions in this paper. Melting point of molten salt, as the most important basic character, is the primary parameter to select molten salt. Melting point and decomposition temperature are measured by Simultaneous Thermal Analyzer. The results show that melting points of major ternary carbonates are close at around 400°C and decomposition temperatures of most ternary carbonate are between 800 and 850°C. In accordance with energy variation, when the system is cooled from the molten state, precipitates of crystalline phases is orderly. Crystallization temperatures of some samples are much higher than their melting points. Therefore, through comparative experimental study of heating and cooling, 10 kinds of mixed carbonates with low melting point and crystallization temperature were selected primarily. Then, latent heat, density and thermal stability of these mixed salts were studied.