CONICET | Buscador de Institutos y Recursos Humanos

It is known that the cation exchange property presented by zeolitic materials is one of their fundamental characteristics for their application as heavy metals immobilizer in purification processes. Up to the present time, exchange processes of zeolites with mono and divalent cations have been widely studied. Additionally, although exhausted FCC catalysts are classified as a safe waste, the amount produced is significant and when its useful life is finished, the used catalyst constitute a residue difficult to be handled. Most of exhausted catalysts are disposed as land fill, so it could be attractive the possibility of using them as raw material for zeolite synthesis. Previous experiments showed that the alkaline fusion functions as an alternative way to increase the reactivity of solid phases, favoring the amorphization of kaolins used to obtain zeolites. On the other hand, there exist antecedents about the use of natural or artificial zeolites in cementiteous materials. Taking into account these assumptions and considering the quality and quantitative composition of exhausted FCC catalysts, their conversion reaction in zeolite-rich materials is optimized by using the alkaline fusion as activating pretreatment. The reaction products are used to evaluate their capacity to eliminate the Cr(III) cation present in aqueous solution. The solid residues obtained after cation exchange, mostly Cr(III)-containing zeolites, were incorporated to cementiteous matrices on which lixiviation studies of this cation were performed.