Molecular Dynamics Study On The Impact Of Electrostatic Field On Crystallization Of Calcium Carbonate Liquor

Water scale deposit caused a lot of economic and technical problems to industrial and civil equipment. The chemical control method brought not only pollution to environment, but corrosion to equipment reducing its service life. Therefore, the electrostatic water treatment technology is springing up and becoming one important trend of water treatment. It is easy to operate, free of pollution, simple in structure, outstanding in effect and with low running cost.Due to confusion of water system, however, many challenges emerge when efforts are made to explain the mechanism of electrostatic field. At present, study and assessment on electrostatic water treatment technology mostly rely on experimental or theoretical extrapolation, which waste time, manpower and material. Even worse, the experiment errors make it desperate to reach a complete explanation to the functioning mechanism of electrostatic field. A new research approach is thus in strong demand.In light of molecular dynamics simulation method, this thesis discussed the mechanism of electrostatic water treatment technology from the micro point of view, which may provide theoretical foundation for research of electrostatic water treatment technology. Since water scale mainly deposits on the internal surface of water pipes and cooling units, this thesis mainly calculated the scale forming process on calcite crystal plane and iron crystal plane, and elaborated the changes of absorption energy, pair correlation functions and self-diffusion coefficient. The result shows the electric field reduced the absorption energy by 120% and hence can effectively prevented the free state Ca 2+ , CO3 2? ion from being absorbed to the scale forming crystal plane. The pair correlation functions of Ca 2+ on the calcite crystal plane and Oxygen atom in the water both arrive at peak around 0.23nm , indicating forming of ionic bond in between and good hydrolysis of scale molecular. The change of self-diffusion coefficient leads to remarkable increase of the anisotropy of the liquid. The scale crystal thus can not develop normally as per dynamic theory of crystal growth, the deposit state changed, which impacts on the shape of the scale. As the growing awareness of environment protection and running shortage of water resources, the electrostatic water treatment technology will certainly draw more popular and serious attention and calls for more systematic research.