Study On The Cooling Crystallization Process Of Copper Sulfate Pentahydrate

Copper sulfate pentahydrate is an important inorganic chemicals which is widely used in chemical industry and electronic industry, as well as being used in agriculture, as a mineral additive to animal food and as a pesticide.Due to the bad crystal habit and crystal size distribution of the product from the domestic factory and the higher content of impurities, the quality of copper sulfate pentahydrate has been affected by these factors. In order to solve these problems, this article studied the thermodynamics, kinetics, crystal morphology and crystallization process systemically.The solubility of the copper sulfate pentahydrate in the water at different temperature is measured by the equilibrium method, and the equation of copper sulfate pentahydrate are fitted via the solid-liquid equilibrium experiential equation. At the different temperature the metastable zone width, which is used for optimizing the operational conditions,of the analytic copper sulfate pentahydrate and the copper sulfate pentahydrate with impurities are measured by the naked eyes.The crystallization kinetics of copper sulfate pentahydrate is measured by batch transient method, and the effect of impurities on crystallization kinetics is studied. The kinetics equation is obtained by regression method.The crystal structure was measured by X ray single crystal diffraction and its crystal habit was analyzed by material studio software. The effect of impurities on crystal habit was also studied experimentlly.The optimized operational conditions are confirmed by studying the effects of the initial concentration , seed ,cooling rate and stirring speed on the crystal size and the crystal size distribution. The quality of copper sulfate pentahydrate accord with the nation standard, and the crystal size and crystal size distribution are superior to the product of factory.