The Research On Fluorite Beneficiation Fluoride Wastewater

With the development of modem industry, the production, composition and application of Fluorine and fluoride is more and more wide. Many industries, such as exploitation and processing ore containing fluorine, metal smelting, Al-electrolysis, glass, electroplating, chemical fertilizer, pesticide and chemical industry, produce more and more wastewater which contains high fluorine and fluoride. The fluorine and fluorine are badly polluting environment. Especially for ten years, electronics industry, such as color picture tube, integrated circuit, develops rapidly. The effluent amount of fluorine and fluoride is on the increase with each passing day. The pollution of fluorine and fluoride is taken seriously by people of the world.This paper aims at the fluorine of beneficiation wastewater, it adopt chemical precipitation to union with coagulating sedimentation, and study the influence of different precipitating agent and flocculating agent on wastewater treatment, and the optimal running condition of this craft. First, it compared with the effect of three kinds chemistry precipitant. Quicklime can cut the fluorine down to 43.5mg/L, milk of lime can cut the fluorine down to 35.08mg/L. If chose the neutral CaCl2 to remove fluorine, it can simplify the treatment process, and cut the fluorine down to 15.1mg/L. The treatment effect of CaCl2 is much better then quicklime and milk of lime. Then it compared with the effect of three kinds of flocculant. PFS can cut the fluorine down to 8.9mg/L or so, and the aluminum sulfate can cut the fluorine down to 8.95mg/L or so. The PAC can cut the fluorine down to 2.56mg/L or so, the effluent of water quality is stable and good treatment effect. The experiment of reality wastewater verification amplification indicate that the reality wastewater can reach the same treatment effect as artificial wastewater, the fluorine concentration of effluent is 3.22 mg/L, and the removal rate 97.78%. The sedimentation experiment indicates that the precipitation effect of flocculate is good, it can be precipitated completely basically in half an hour.The experimental results evident that, in the first stage, the usage of calcium chloride should control at 0.8 g/L or so, and the mixing time should control at 30 min or so, and the mixing strength 300~350 r/min. In the first stage, the concentration of fluorine in filtrate could be controlled under the level of 20 mg/L. When control the usage of 10 % PAC at 0.7 g/L or so, pH 7~7.5, mixing strength 300 r/min, mixing time 5~10 min. The concentration of fluorine in the supernatant fluid could be controlled under 4 mg/L steadily.