Physicochemical Particular Qualities of the Crystallization Process of Inorganic Heat-Storage Materials’ Melts

Investigations of the cluster-coagulation model for some inorganic substances and mixtures of sodium thiosulfate with salts of elements (VI) of A, B groups have been carried out. The doping of sodium thiosulfate pentahydrate with sodium selenate, tellurate, molybdate and tungstate has been carried out. The thermodynamic parameters of associate formation processes between sodium thiosulfate and salts formed from oxygen-containing acids of selenium, tellurium, molybdenum and tungsten have been calculated. The amount of heat introduced by the modifier (selenate, tellurate, molybdate and tungstate of sodium) into the total heat-accumulating effect of the mixture Na2S2O3∙5H2O – Na2XO4 (X – Se, Te, Mo or W) mixture has been calculated. The number of n-particle clusters and the diameter of clusters that are formed in the melt of the Na2S2O3∙5H2O – Na2XO4 mixture have been calculated. It is shown that special effects of systems based on mixtures consisting from sodium thiosulfate pentahydrate and salts of selenium, telluric, molybdenum, tungsten acids could be explained by more excessive tendency of these structures to the hydrate formation, associative stability and polymerization for the reason that rare elements’ ions in anionic form stabilize associates of sodium thiosulfate with water molecules that leads to growth the heat storage capacity. The scientific and practical significance of this research refers to the probability of prediction physicochemical properties of modified heat-accumulating materials based on the cluster-coagulation model.