The Experiment Study On Fluoride Purification Via Modified Diatomite From Zinc Sulfate Solution In Zinc Metallurgy

China is the world's largest countries of zinc producer and consumer. In recent years, with the expansion of production capacity of zinc, the production of zinc concentrate can not meet demand. The import of complex zinc concentrate(high fluoride in zinc concentrate) has become one of the main raw material in zinc production. These could lead to high fluorine in system of zinc hydrometallurgy production, and the production process and electrowinning are seriously influenced.It would lead to corrosion of the plate during electrolysis and the difficulties in stripping zinc. The removal of fluorine in zinc hydrometallurgy become a common problem in this industry. Therefore, to carry out the removal of fluoride has a great significance.Based on the literature, it was carried out to research removal of fluorine in zinc sulfate solution by diatomite. According to the internal structure of diatomite, The preparation of technology of modified diatomite adsorbent by aluminum sulfate was proposed. The methods of firing, acidification and the introduction of a positively elements were applied. According to the activation of diatomite, preparation of diatomite, sorbent performance testing and research of fluorine removal properties of zinc sulfate solution, the defluorination properties were studied by modified diatomite. In the base of these studies, the adsorption kinetics of the modified diatomite was studied, and the mechanism of defluorination was proposed.During the defluoride experiment, the aluminum sulfate concentration, aluminum sulfate modification time, liquid to solid ratio and the dosage of modified diatomite, adsorption time, the solution p H, temperature were investigated. The results showed: aluminum sulfate concentration was 0.3mol/L, the time was 4h, the ratio of liquid to solid was 20:1, the calcination temperature was 500?.Through many testing means, the surface of modified diatomite was loaded aluminum element, and the number of pores was increased, surface area was increased about five times, negative surface potential became positive.The prepared diatomite were applied into zinc sulfate solution. The results showed: the dosage of modified diatomite was 15g/L, adsorption time was 30 min, the p H was 4, the adsorption temperature was 45?. the fluoride concentration in zinc sulfate solution was reduced from 200mg/L to 85mg/L.In the study theory of the removal fluoride by modified diatomite, Langmuir model and Freundich model were studied. The adsorption fluoride of modified diatomite was more in line with the Langmuir model, the adsorption process was more in line with the pseudo second kinetic model; And the removal fluoride process was physical adsorption, and chemical adsorption.The adsorption was the process of diffusion-reaction-diffusion.In this research work, preparation conditions of modified diatomite and parameters of defluoride were proposed. The adsorbents were a wide range of sources, gotten easily, and without introducing secondary contamination in the adsorption process. It is a better defluoride method in zinc sulfate. It provides a effective method for the production of zinc hydrometallurgy. There is an important reference value.