A Study On The Thermodynamic Properties Of Copper And Cobalt Chloride

Abstract:The thermodynamic properties of electrolyte solution play an important role in the exploitation of mineral resources, establishment of high efficiency and low energy consumption of met allurgy technology to extract copper and cobalt in their ores. Meanwhile the accurately thermodynamic data of electrolyte aqueous solution are needed in many fields, such as chemistry, biological sciences, geology and industrial system. In this papper, the thermodynamic properties of copper and cobalt chlorides were studied by calorimetric method. The main researches and results are listed as follows:The enthalpies of dissolution of CuCl2·2H2O(s) at298.15K,308.15K,318.15K and CoCl2·6H2O(s) at298.15K,308.15K,318.15K,328.15K,338.15K have been measured. The equations for calculating the enthalpy of dissolution have been fitted, and the coefficients in Pitzer model for the relative apparent molar enthalpy equation at different temperature were calculated.The weight loss of CuCl2·2H2O(s) and CoCl2·6H2O(s) were studied by TG analysis. The phase transformation of CoCl2·6H2O(s) with the temperature was determined. The endothermic effects of CuCl2·2H2O(s) and CoCl2·6H2O(s) are measured by C80microcalorimeter between298-473K. Then the thermal decomposition mechanism of CuCl2·2H2O(s) and CoCl2·6H2O(s) was discusssed.The μRC micro titration calorimeter was calibrated and corrected, the results of the enthalpies of dissolution and the mixing measured by μRC micro titration calorimeter and C80microcalorimeter were compared, and the reasons of error were also discussed.