A method for comprehensive recovery and utilization of waste rare earth type Y molecular sieve catalyst

Abstract

The invention relates to a comprehensive recycling method of a waste rare-earth type Y-type molecular sieve catalyst. The comprehensive recycling method includes the following steps that firstly, the waste catalyst is stirred in a mixed acid solution with low acidity, so that most of rare earth is separated from a parent solution; secondly, the solid catalyst separated out is subjected to secondary stirring treatment in a mixed acid solution with high acidity, so that enough rare earth is separated from the parent solution, and since a molecular sieve of the parent solution is subjected to two times of acid leaching, the heavy metal content loss of a slag sample is small, and subsequent utilization is easy to implement; and finally, the solid molecular sieve slag sample is ground to be ultra-fine powder, and the ultra-fine powder is blended to the preparation of an SCR catalyst so as to replace part of titanium dioxide, so that the emission of heavy metal is reduced, the intensity of formed catalysts is increased, and meanwhile the denitration activity is not be reduced too much. An acid-containing solution is used as the parent solution for preparing polymer aluminum chloride after the rare earth is separated out, and the turbidity reducing effect of products is not affected, and is superior to the turbidity reducing effect of industrial polymer aluminum chloride.

Description

Technical field [0001] The invention relates to a method for recycling waste catalytic cracking catalysts, in particular to a method for recycling rare earth, aluminum and molecular sieve seeds in waste rare earth type Y molecular sieves. The invention belongs to the field of comprehensive utilization of rare earth catalysts. Background technique [0002] At present, rare earths are widely used in the field of catalysts. The domestic consumption of rare earths in the petrochemical field alone accounts for more than 10% of the total consumption of rare earths. Rare earth Y molecular sieves have been widely used in catalytic cracking since the 1960s, and this trend has been transferred to other molecular sieve catalysts. Nowadays, with the increasing shortage of resources, the recovery of rare earth components from the preparation process of petrochemical catalysts or catalyst waste has very good social and economic benefits. [0003] CN200510046121 proposes a method for dissolving ...

AI Technical Summary

Problems solved by technology

[0007] The present invention aims at the deficiencies in the current technology of recovering rare earth and other useful elements from waste rare earth type Y molecular sieve catalysts, and develops a two-step low-acid dissolution treatment method for waste rare earth type Y molecular sieve catalysts. The acid-dissolved molecular sieve still contains vanadium , nickel and other heavy metals can be doped into the selective catalytic reduction (SCR) catalyst for flue gas denitrification, and the aluminum-containing solution after rare earth recovery can be used as a raw material for polyaluminum chloride