NaY molecular sieve modifying method

Abstract

A NaY molecular sieve modifying method includes: adding mixed acid into mixed liquid of NaY molecular sieve, buffer solution and water and beating uniformly, using the buffer solution to adjust pH to be 4.0-6.5, and performing exchange reaction at the temperature ranging from 70 DEG C to 95 DEG C; filtering the exchanged slurry to obtain a filter cake, washing the filter cake with deionized water, drying, adding starch, adding water, stirring, leaching and drying. Using the NaY molecular sieve modifying method can realize ammonia (ammonium)-free emission, and on one hand, the service life of equipment is prolonged, on the other hand, environment pollution can be reduced while the problem of waste water treatment of the ammonium salt method can be solved. Na2O content of a product obtained by the method can be reduced smaller than 0.5%, and crystallinity of the product can reach more than 85%.

Description

technical field [0001] The invention relates to a modification method for artificially synthesizing Y-type molecular sieves, in particular to a method for modifying NaY molecular sieves with organic mixed acids Background technique [0002] Molecular sieves are generally artificially synthesized zeolites, which are aluminosilicate compounds with cubic lattices. Neat, large internal surface area holes remnant metal ions and hydrated water with low charge and ionic radius. Molecular sieves have special selective catalytic properties due to their uniform composition, regular structure, adjustable surface acidity and molecular size pores. field dominates. [0003] Synthetic molecular sieves generally contain sodium, which exists in the form of non-skeleton cations to neutralize the negative charges on the molecular sieve skeleton, but sodium-type molecular sieves are not acidic, and need to be converted into hydrogen-type or polyvalent metal-type by ion exchange After molecul...

AI Technical Summary

Problems solved by technology

On the one hand, the resin blocks the sieve holes, and the viscosity of the molecular sieve makes the separation incomplete, which increases the regeneration of the resin and causes the waste of the molecular sieve

[0009] Ion exchange resin does not directly contact NaY molecular sieve. Although the content of sodium oxide can be reduced and the resin can be reused, excessive resin will greatly damage the molecular sieve structure.