Method for preparing ZSM-5 molecular sieve by using solid wastes

Abstract

The invention relates to a method for preparing a ZSM-5 molecular sieve by using solid wastes, in particular to a preparation technology for synthesizing the ZSM-5 molecular sieve by using rice husk ash, iron tailings, gold tailings and other solid wastes as raw materials to provide all or part of silicon sources and aluminum sources required by the synthesizing of the ZSM-5 molecular sieve without solvent and NaOH (sodium hydroxide). The method comprises the following steps of mixing the silicon sources, the aluminum sources, Na2CO3-10H2O, a template agent or crystal grains, directly puttinginto a reaction kettle, and crystallizing at constant temperature, so as to obtain the ZSM-5 molecular sieve. The method has the advantages that by applying the Na2CO3-10H2O into the technology usingthe solid wastes as the raw material to synthesize the ZSM-5 molecular sieve, the secondary pollution is avoided in the synthesizing process; by using the rice husk ash, the iron tailings, the gold tailings and other solid wastes as the raw materials to synthesize the ZSM-5 molecular sieve by a non-solvent method, the technology is simple, and the application range is wide; the problem of environment due to solid wastes is relieved, and the utilization of solid wastes with high added value is realized.

Description

technical field [0001] The invention belongs to the fields of molecular sieve preparation and environmental protection. Specifically, it involves using rice husk ash, iron tailings and gold tailings to provide all or part of the silicon and aluminum sources required for the synthesis of ZSM-5 molecular sieves, and at the same time synthesize ZSM-5 containing hierarchical pores without the participation of solvent and NaOH A method for preparing ZSM-5 molecular sieves by using solid waste. Background technique [0002] Since ZSM-5 molecular sieve was first reported by Mobil Corporation of the United States (USP3702886) in 1972, due to its unique pore structure and shape-selective catalysis, it has been applied in many oil refining and chemical processes, and its preparation method is also constantly improving. From the initial synthesis using organic amine templates to the subsequent amine-free synthesis, the manufacturing cost of ZSM-5 has been significantly reduced, and th...

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Problems solved by technology

The above methods cannot completely avoid the use of solvents in the process of preparing ZSM-5 molecular sieves, resulting in a large amount of alkali-containing wastewater and reducing the space utilization of molecular sieve synthesis equipment

Solvent-free method means that no solvent is used in the molecular sieve preparation process. At present, the solvent-free method mainly uses pure chemical reagents as raw materials. After simple mixing and grinding, it is directly placed in a reaction kettle and sealed at a certain temperature for synthesis. This process is simple. , high equipment utilization, but the synthetic raw materials contain NH 4 F, NH 4 Cl and other substances harmful to the environment are not suitable for large-scale industrial applications, and there is no report on the synthesis of molecular sieves using solid waste as raw materials using a solvent-free method

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