ResumoEsse trabalho discute a aplicação de resinas de troca iônica com matriz poliacrílica para a adsorção de cianocomplexos metálicos. Ensaios em batelada mostraram que as resinas possuem elevada afinidade para os cianocomplexos de ferro e de zinco em relação aos de cobre. Já a eluição, estudada em coluna, indicou que soluções de tiocianato de sódio a 1mol/L são capazes de eluir os ciancomplexos dos três metais. Já soluções de nitrato de só-dio, na mesma concentração, não são efetivas para a eluição do cianeto de zinco. Um processo de eluição seletiva é proposto onde os cianocomplexos de cobre e de ferro são eluídos com solução íons NO 3 -. Em seguida, o zinco é eluído com NaSCN. Ambos eluentes foram capazes de concentrar os cianocomplexos de solução, o que tem efeito benéfico nas etapas subseqüentes de regeneração do cianeto.
Palavras-chave:Cianetos metálicos, reciclagem, resinas de troca iônica, resinas poliacrílicas.
-Ion exchange resins can potentially be applied in cyanide recycling to address growing environmental concerns over the use of cyanide during gold extraction. In the present work the elution of copper-, iron-, and zinc-cyanocomplexes from polyacrylic-and polystyrene-based resins was studied. It was found that iron and copper cyanides are easily eluted from polyacrylic-and polystyrene-based ion exchange resins using either SCN -or NO 3 -. However, elution of the zinc cyanide complex from polystyrene-based resins was poor when using nitrate solution as eluant. Besides, an increase in elution temperature from 25 °C to 50 °C improved the elution of iron and zinc cyanides from polystyrene-based resins using a nitrate eluant; however temperature did not have any significant effect on other metal cyanocomplexes or for elution using thiocyanate. It was therefore proposed that the optimal combination of resin-eluant was site-specific, and depends on the features of the effluent, processing temperature, eluant concentration, and ion exchange resin under consideration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.