Preparation of 13X zeolite by coal fly ash for adsorption of volatile organic compounds

Coal fly ash is a large amount of industrial solid waste,which greatly harms the natural environment and human physical and mental health. How to use it efficiently and at a high value is a scientific and technical problem facing us.Volatile organic compouads are a type of volatile organic pollutants that have a "three effects" effect on the human body. Molecular sieve is widely used in many fields because of its unique pore structure,excellent ion exchange,catalysis and adsorption performance. The 13X zeolite was prepared by alkali fusion activation combined hydrothermal synthesis by the coal fly ash in the experiment. The factors of Si/Al ratio,alkalinity and crystallization time were analyzed in the preparation of 13X zeolite. The VOCs adsorption properties of 13X zeolite and activated carbon were investigated. XRD,SEM and BET are used to characterize the structure of molecular sieve crystal form,larger surface area and pore size. It was found that 13X zeolite is of good crystallinity and high purity by XRD,SEM,EDX and chemical composition analysis. The particle size ranges from 1 to 3 μm which is almost uniform. The BET specific surface area reaches 990.3 m2/g and the total pore volume is about 0.72 cm2/g. The average pore diameter is 1.1 nm. The type of zeolite was influenced by the Si/Al ratio. The crystallization rate is accelerated and the crystallization time is shortened by increasing the alkalinity,which promote the polycondensation reaction of silicate with aluminate ions. Zeolite are generated quickly during the crystallization stage. It was found that the VOCs adsorption capacity of 13X zeolite is higher than that of activated carbon. [JP3]The greater the polarity of VOCs molecules,the higher the adsorption capacity. Through the research in this paper,it not only achieves the purpose [JP3]of "treating waste with waste,turning waste into treasure" between solid waste and waste gas,but also provides ideas for low-cost and efficient synthesis of zeolite molecular sieve. At the same time,it improves the utilization of bulk solid waste,and explores the synthesis of molecular sieve. The conditions in turn provide technical and theoretical support for the industrial application of molecular sieves.