Characteristics and Forms of Fluoride Pollution in Electrolytic Aluminum Production
Electrolytic aluminum industry in Yunnan Province has been developing rapidly in recent years.The environmental pollution caused by fluoride discharge has been an issue of concerned.Taking an electrolytic aluminum material factory as the research object,the content and existence form of fluoride in solid waste of electrolytic aluminum material production were detected,the raw materials,products and solid waste in the production process determined,and the fluoride balance calculation was carried out according to the actual situation.During the production of electrolytic aluminum materials,99.6% of fluoride was carried-by solid waste,and 0.4% of fluoride entered the external environment in the form of organized flue gas and unorganized skylight exhaust gas.The pollution of fluoride to the environment can be reduced by adding high efficiency desulfurization and cooperative defluorination facilities and improving the gas collection efficiency of electrolytic cell.The fluoride in solid waste was found to be insoluble or slightly soluble in water,such as Na5Al3F14,NaAlF4,Na3AlF6,K2SiF6,CaF2 and AlF3.The content of water-soluble fluoride in the soil accounted for less than 1% of the total fluoride,indicating that there was a certain correlation between fluoride discharge and soil environmental pollution.The cumulative effect of fluoride in soil is obvious.Under the conditions of the first type of land and the second type of land,the total hazard index of fluoride in the surface soil around the electrolytic aluminum plant is 0.794 and 0.09,respectively.The health risk assessment results of the surrounding soil are acceptable.
electrolytic aluminum materialfluoride logisticsoccurrence formpollution control
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NSTL
万方数据
维普
