Recuperação de metais de catalisadores mássicos e monometálicos

Química Nova

Júlio Carlos Afonso¹  Tatiana Siqueira De Lima¹  Paula Constante Campos¹  Ana Acácia De Sá Pinheiro¹ 

[1] ,Universidade Federal do Rio de Janeiro Instituto de Química Departamento de Química AnalíticaRio de Janeiro RJ

关键词: spent catalyst;    metals recovery;    fluoride ion;   

DOI  :  10.1590/S0100-40422003000600024

来源: SciELO

【 摘 要 】

This work presents a study on the dissolution of some commercial monometallic and non-supported deactivated catalysts in HF + H2O2 mixtures (and, eventually, other media) under mild experimental conditions, after a previous oxidation step. The samples were neither crushed nor grinded. The best experimental conditions were dependent on the nature of the support and of the active phase. For example, the Pt/Al2O3 catalyst was dissolved in about 10 minutes, without agitation and heating; however, dissolution of the Pd/Al2O3, Ni/Al2O3, Ni/SiO2, Cu/Al2O3 and V2O5 samples required a temperature of 60 ºC and an agitation of 400 rpm. A careful addition of a NaOH solution allowed a quantitative precipitation of aluminium as criolite (Na3AlF6) or precipitation of Si as Na2SiF6; NaF was obtained as a by-product. As expected, processing of Pd/C, V2O5 and CuO.Cr2O3 samples was relatively simple. Metals recovery from catalysts reached a quantitative level in all samples studied; it is particularly interesting that platinum and palladium could be easily recovered in a single step process, thus separing them from aluminium.

【 授权许可】

CC BY-NC   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License