基于沉淀法和吹脱法的磷石膏浮选废水脱磷氟氮工艺研究OA

Phosphogypsum flotation effluent contains impurities such as phosphorus,fluorine,and nitrogen,which can reduce the performance of phosphogypsum products.This article explores the effects of CaO addition time inter-vals on the particle size and microstructure of precipitation products in simulated flotation effluent containing phos-phorus(fluorine)and ammonia nitrogen by precipitation method and air stripping method.The results show that in simulated flotation effluent containing phosphorus,as the CaO addition time interval increases,the particle size of pre-cipitation products gradually increases.The average particle size of precipitation products at a time interval of 40 minutes is 20 μm;The addition time interval of CaO has little effect on the crystallization effect of the precipitation products of fluorine-containing simulated flotation effluent,with an average particle size of 1～2 μm.When CaO was added to the phosphogypsum flotation effluent discharged by a certain enterprise in Sichuan with a time interval of 40 minutes,the average particle size of the precipitate was 20 μm.The mass concentrations of phosphorus and fluoride in the treated wastewater were 22.4 mg/L and 46.2 mg/L,respectively,and the removal rates were 99.8%and 94.9%,respectively;The static blow off treatment of ammonia nitrogen was carried out on the phosphogypsum flota-tion effluent from which phosphorus and fluoride had been removed.The results show that when the aeration rate was 1.5 m3/L,the CaO addition rate was greater than 2 g/L,and the deamination agent dosage was 0.1 g/L,the residual mass concentration of ammonia nitrogen in the phosphogypsum flotation effluent was 7.8 mg/L,and the removal rate reached 97.47%.The treated wastewater can be recycled.