Treatment and resource recovery from inorganic fluoride-containing waste produced by the pesticide industry  

作　　者：Yang Li Hua Zhang Zhiqi Zhang Liming Shao Pinjing He 

机构地区：[1]State Key Laboratory of Pollution Control and Resources Reuse, Tongji University [2]Institute of Waste Treatment and Reclamation, Tongji University [3]Research and Training Center on Rural Waste Management, Ministry of Housing and Urban–Rural Development of P.R.China

出　　处：《Journal of Environmental Sciences》2015年第5期21-29,共9页环境科学学报（英文版）

基　　金：supported by the Hi-Tech Research and Development Program (863) of China (No. 2007AA061300);the Innovation Program of Undergraduate Students in Shanghai Province (No. 0400107092);Collaborative Innovation Center for Regional Environmental Quality

摘　　要：The rapid development of the fluorinated pesticide industry has produced a large amount of fluorine-containing hazardous waste, especially inorganic fluoride-containing waste（IFCW）. A two-step process, including extraction and recovery, was developed to recover fluorine as synthetic cryolite from IFCW produced by the pesticide industry. The optimum conditions for extraction were found to be a temperature of 75℃, an initial p H（p Hi） of 12, a4-hr incubation time and a liquid-to-solid ratio of 40 m L/g; these conditions resulted in a fluorine extraction ratio of 99.0%. The effects of p H and the F/Al molar ratio on fluorine recovery and the compositional, mineralogical and morphological characteristics of the cryolite products were investigated. Field-emission scanning electron microscopy of recovered precipitates showed changes in morphology with the F/Al molar ratio. Coupling Fourier transform and infrared spectroscopy, X-ray diffraction indicated that the formation of Al F3-6was restricted as increasing p H. Both the amount of fluorine recovered and the quality of the cryolite were optimized at initial p H = 3 and a F/Al molar ratio 5.75. This study proposed a reliable and environmentally friendly method for the treatment of fluoridecontaining wastes, which could be suitable for industrial applications.The rapid development of the fluorinated pesticide industry has produced a large amount of fluorine-containing hazardous waste, especially inorganic fluoride-containing waste（IFCW）. A two-step process, including extraction and recovery, was developed to recover fluorine as synthetic cryolite from IFCW produced by the pesticide industry. The optimum conditions for extraction were found to be a temperature of 75℃, an initial p H（p Hi） of 12, a4-hr incubation time and a liquid-to-solid ratio of 40 m L/g; these conditions resulted in a fluorine extraction ratio of 99.0%. The effects of p H and the F/Al molar ratio on fluorine recovery and the compositional, mineralogical and morphological characteristics of the cryolite products were investigated. Field-emission scanning electron microscopy of recovered precipitates showed changes in morphology with the F/Al molar ratio. Coupling Fourier transform and infrared spectroscopy, X-ray diffraction indicated that the formation of Al F3-6was restricted as increasing p H. Both the amount of fluorine recovered and the quality of the cryolite were optimized at initial p H = 3 and a F/Al molar ratio 5.75. This study proposed a reliable and environmentally friendly method for the treatment of fluoridecontaining wastes, which could be suitable for industrial applications.

关 键 词：Fluoride-containing waste Fluorine extraction Fluorine recovery Cryolite 

分 类 号：X786[环境科学与工程—环境工程]