Research On The Recycling Use Of Exhaust AlF₃by The30000t/a Dry Method

The technology of dry process production has replaced the one of traditional wet process production,because of its simple process,less investment,quick effect,rapid development speed and so on.According to statistics,there are23enterprises of dry process AIF3in China.The total production is up to1.12million tons.The main elements of dry method aluminum fluoride emissions are HF and SiF4. With the expansion of aluminum fluoride enterprise of dry process in recent years,the gas pollution that the technology of fluoride waste led to is more and more terrible.Therefore,the study on the recycling of dry aluminum fluoride tail gas has become particularly important.For the current situation of tail gas treatment with dry method aluminum fluoride.This article mainly expounds the harm of fluoride waste gas and the importance of its recycling,and introduce the recycling methods and direction of dry method aluminum fluoride gas.To improve the utilization of exhaust heat energy,it is better to adopt the direct way for aluminum fluoride gas.Because dry method aluminum fluoride gas contains a amount of hydrogen fluoride,and carries considerable quantity of heat.Considering above exhaust characteristics,we can use the quantity of heat to make the materials drying.The final combination of aluminum fluoride production process of aluminum hydroxide,which is to be used by the natural gas from the wet to the dry process.So decided to direct use exhaust gas to dry the aluminum fluoride hydroxide of wet state.We decide to use the fluidized bed, which can reflect the design process.When the exhaust gas dried aluminum hydroxide of wet state in fluidized bed,we can make use of waste heat of exhaust gas,and can remove exhaust gas of hydrogen fluoride.The way saves the process of purifying exhaust,virtually reduces the economic burden of the enterprise.A large number of water vapor and exhaust gas is produced in the fluidized bed,which is recycling and condensating into implement through the jet pump.The heat can make the water have higher temperature.they provide water of high temperature to take warm and have a bath.This method can reflect the principle of reuse of resources,a large amount of condensed water can make use of the axial flow turbine driven generators.By the simulation results we can conclude this method is feasible in the implementation process.This method not only recycles a large number of water vapor and a small amount of hydrogen fluoride in the exhaust gas,but also make use of exhaust heat of.According to the design process,we calculated the whole process for the material and heat,as well as we selected the equipment and evaluated the technology for economic.Finally concluded the result in this paper,the method can not only solve the problem of aluminium fluoride exhaust gas,has also made full use of the waste heat, and reflect grade of the energy in the process,increase the energy density,achieve the saving of resources and using of circulation,we can regard the method as a better reference.