Study On Cleaning And Recycling Of Wast PTFE Bag

Coal-fired power plants, waste incinerators, cement, iron and steel production enterprises soot emissions are the main source of pollution of the atmosphere. Baghouse technology can capture fine dust, smoke dust effectively remove pollutants in coal-fired power plant boiler dust, large cement kiln and kiln dust, waste incineration exhaust gas purification and other fields have a wide range of applications. PTFE fiber, fabric bags and film media and other accounts for about 20% of the high-temperature bag material production, is one of the key materials to achieve energy saving and pollutant emission control dust. PTFE filter bag average life of three years, each year about 2,000 tons of waste to be recycled PTFE filter bag. PTFE filter bag recycling of waste not only has high economic value, but also important environmental significance.In this paper, a strong acid and oxidizer cleaning PTFE waste bag, and then subjected to heat treatment of waste bag, then ball milled PTFE powder, its recycling. In this paper, detergent ingredients, cleaning effect of temperature and time on whiteness and mechanical properties of the waste bag, Optimum cleaning process; investigate the effect of heat treatment temperature and time on the bag crystallinity; research milling speed and time on Effect of PTFE powder particle size and other properties. The main contents and conclusions are as follows:1.10% Na Cl O can effectively remove the organic matter from PTFE, The increase of temperature and is in favor of cleaning cloth, but the temperature should be not higher than 45 ℃, or Na Cl O will decomposite severely. The effect of H2SO4-HCl O4 remove metal oxides is obvious, and can oxidize some organic matter. H2SO4 and HCl O4 optimum ratio is 1: 1, increasing test temperature and time is in favor of washed effect. At room temperature, It soaked in 10% Na Cl O for five days, then 1: 1H2SO4-HCl O4 solution at 70 ℃ for 10 h, whiteness can reach 80.3%.2.Increasing the temperature for heat treatment can improve the crystallinity and melting point at the appropriate temperature range.When the temperature is higher than 380 ℃, it will make PTFE molecular degradate..Therefore, the degree of crystallinity and melting point also declines.Under the condition that the temperature is less than 380 ℃,to prolong the time of heat treatment brings minor impact to crystallinity and tensile proerties. When PTFE macromolecular degradates, its toughness and elongation decreases. In the stretching process it will suddenly break.3. Best grinding parameters is 500r/ min, 1.5h, φ15mm ball.With the incresement of PTFE fineness,the shear strength grows.When the mesh is up to 300,the growth rate become slow.The shear strength of new material is higher than recycle one.Because binding force of particle surface become worse when recycle PTFE material process repeated sintering. New materials and recycled material of PTFE mixed with 3: 1, the shear strength of finished product is about 96% of new material. Pure recycled material is only 80%. on the basis of new, recycled material 3: 1, add 20% the total mass of carbon fiber powder, the shear strength is improved about 1.3 times than new material. While continuing to increase the content of carbon fiber powder, because of poor compatibility from two interface, adhesion strength becomes weak,the shear performance is worse.