Method for preparing NaY molecular sieve by recycling NaY mother liquor

Abstract

The invention provides a method for preparing a NaY molecular sieve by recycling a NaY mother liquor, and belongs to the technical field of inorganic synthesis. The method solves the technical problems of low NaY mother liquor recycling rate, large pollution, high utilization cost and the like in the prior art. The synthesis method comprises the following steps: (1) stirring NaY mother liquor until the NaY mother liquor is uniform; (2) slowly adding a metered supplementary silicon source into the mother liquor according to the modulus of 3.0-3.4 until the supplementary silicon source is completely dissolved in the pulped NaY mother liquor, and controlling the temperature of the mixture of the NaY mother liquor and the supplementary silicon source to be 30-80 DEG C in the dissolving processto obtain high-modulus recycled water glass; and (3) synthesizing the NaY molecular sieve by utilizing the recycled water glass obtained in the step (2) according to a gel method. According to the method, the NaY mother liquor can be completely recycled, and the pollution of waste liquor and waste residues to the environment is reduced.

Description

technical field [0001] The invention belongs to the technical field of inorganic synthesis, and relates to a method for preparing NaY molecular sieves by reusing NaY mother liquor. Background technique [0002] Since the appearance of Y-type molecular sieve in the 1960s, it has always been the active component of fluidized catalytic cracking catalyst and has an irreplaceable role. At present, the domestic production scale of cracking catalyst has exceeded 250,000 tons / year, and the annual output of Y-type molecular sieve has also reached 100,000 tons. The industrial synthesis method of Y zeolite that each catalyst producer adopts is the water glass and directing agent synthesis method that the flow process is simple and cheap that Grace Company develops, promptly take water glass, aluminum sulfate and sodium metaaluminate as the synthetic raw material, add A certain proportion of the directing agent is crystallized under the induction of the directing agent to form Y-type z...

AI Technical Summary

Problems solved by technology

In addition, the in-situ crystallization method itself will also produce a mother liquor. After the mother liquor produced by its own process is reused in the synthesis, it will basically not be able to use the mother liquor of the gel method.

Because the silicon content in the mother liquor is very low, the reuse of the two mother liquors together cannot meet the water / silicon ratio requirements for synthesizing Y zeolite

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