A method for utilizing molecular sieve synthesis mother liquor

Abstract

The invention discloses a molecular sieve synthesis mother solution using method. The molecular sieve synthesis mother solution using method comprises the following steps: 1, conducting settling separation on a suspended matter of a mother solution to obtain a supernatant liquor, wherein the content of the suspended manner in the supernatant liquor is less than 0.1 g / L; 2, adding lime milk into the supernatant liquor obtained in the step 1), desiliconizing, wherein the content of SiO2 in the desiliconized supernatant liquor is less than or equal to 0.5 g / L; 3, taking the supernatant liquor desiliconized in the step 2) as a clinker in the sintering-process aluminum oxide production technique to dissolve out a regulating solution. The molecular sieve synthesis mother solution using method has the following beneficial effects: the problem that the caustic alkali in the molecular sieve synthesis mother solution cannot be recycled is solved, and the problems of the environment risks that the caustic alkali is directly neutralized by sulfuric acid and is discharged are changed. The method directly combines the production process of a molecular sieve with the production process of aluminum oxide, by removing the silicon in the solution, the molecular sieve synthesis mother solution is desiliconized to dissolve out the clinker, and the dissolved sodium metaaluminate solution is taken as a raw material in the synthesis of the molecular sieve, so that the purposes of recycling of the resources and zero emission are fulfilled.

Description

Technical field [0001] The invention relates to a method for utilizing molecular sieve synthesis mother liquor, and belongs to the technical field of renewable resource devices. Background technique [0002] The synthesis process of molecular sieve is to carry out the hydrothermal synthesis reaction of sodium metaaluminate solution and water glass according to a certain ratio. The synthesized molecular sieve is washed, filtered and dried into finished products for application in the chemical industry. The main components of the mother liquor after the synthesis of molecular sieve are sodium hydroxide solution and a small amount of sodium silicate. The sodium hydroxide content in the solution is 50-60g / l, and the solution is SiO 2 The content reaches 11-14.2g / l, the concentration is high, and the solution contains almost no alumina. In the traditional process of molecular sieve synthesis, the mother liquor is mainly treated by an acid-base neutralization process, that is, the moth...

AI Technical Summary

Problems solved by technology

On the one hand, the caustic alkali cannot be fully utilized, resulting in a waste of resources

On the other hand, the neutralized solution will directly pollute the environment

[0003] CN1631780A discloses a method of using the crystallization mother liquor for producing NaA molecular sieves to replace the original water glass to provide a silicon source, which also saves costs; but the method of adding mother liquor as a raw material to synthesize molecular sieves does not involve the recycling of mother liquor

CN101121522A discloses a method for utilizing the synthesis mother liquor of phosphorus-aluminum molecular sieve, reclaiming the crystallization mother liquor of phosphorus-aluminum molecular sieve for the synthesis of the same type of phosphorus-aluminum molecular sieve, the recycling of mother liquor effectively improves the yield of molecular sieve, the molecular sieve microcrystal in the mother liquor There is a shortened crystallization time of aluminum phosphorus molecular sieve, but through the examples, it can be found that the mother liquor of phosphorus aluminum molecular sieve added in the synthesis is only added in an appropriate amount, and the amount of mother liquor added is not specified in detail. explore