Coal gangue synthesis Zeolite molecular sieve

Gangue is a kind of black gray rock with low carbon content and hardness compared with coal in the process of coal formation, and its output accounts for 10%~15% of raw coal output. Coal gangue is mainly used for power generation, backfilling, land reclamation, production of building materials, minerals and chemical products. The raw materials for the synthesis of zeolite are generally chemical raw materials. Coal gangue contains Al2O3, SiO2 and a small amount of Na, which are necessary for the synthesis of zeolite. It can be used as the raw materials for the synthesis of zeolite to ease the trend of tight supply of raw materials. At present, there are three main preparation methods of gangue zeolite; Hydrothermal synthesis method, alkali fusion method and steam method. Due to the hydrothermal reaction from the surface of the particles to the inside of the particles, the zeolite particle size distribution is wide. The advantage of steam method is that it does not go through the gel stage and the process is short. Microwave assisted hydrothermal synthesis is based on one-step hydrothermal synthesis, and microwave heating is used to replace the traditional heating method. In the process of synthesizing zeolite from fly ash, microwave assisted heating can improve the crystallization speed of zeolite and shorten the crystallization time of zeolite, which provides a reference for microwave assisted synthesis of zeolite molecular sieve from coal gangue. Therefore, the coupling of traditional heating and microwave heating to synthesize molecular sieves has a good prospect in the synthesis of molecular sieves.