Biolixiviação de concentrado calcopiritico utilizando Sulfolobus acidocaldarius
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Data
2019-12-12
Autores
Bocchini, Beatriz Maria Sampaio
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O aumento da utilização de cobre com o desenvolvimento tecnológico tem impulsionado a busca por métodos alternativos de recuperação. A maior fonte natural desse metal é a calcopirita. Entretanto, devido à sua elevada refratariedade, apresenta aplicabilidade econômica apenas mediante extração por processos agressivos ambientalmente e com elevado aporte financeiro. Nesse contexto, buscam-se processos mais amenos e baratos para a recuperação desse metal utilizando calcopirita a fim de aumentar os lucros e minimizar o problema ambiental. Dentre esses processos, destaca-se a biolixiviação, técnica que usa microrganismos capazes de obter energia a partir de sulfetos metálicos. No caso específico da calcopirita, tem se mostrado muito promissora a utilização de arquéias em meios com baixo potencial para recuperação de cobre. Isso porque esses potenciais são capazes de fragilizar a calcopirita e aumentar sua solubilização. Sendo assim, esse trabalho mostra a utilização da arqueia Sulfolobus acidocaldarius na biolixiviação de concentrado calcopirítico em meios contendo íons ferrosos (0,200 mol L-1). Os resultados foram satisfatórios, ao redor de 86,6% de extração de cobre após 110 dias, demonstrando a potencialidade desse microrganismo em manter baixos valores de potencial e proporcionar uma recuperação de cobre eficiente mesmo após grande intervalo de tempo. Outra vantagem adicional foram as elevadas temperaturas que favoreceram ainda mais o processo.
The increased use of copper with technological development has driven the search for alternative recovery methods. The largest natural source of this metal is chalcopyrite. However, due to its high refractoriness, it has economic applicability only through extraction by environmentally aggressive processes and with high financial contribution. In this context, we seek milder and cheaper processes for the recovery of this metal using chalcopyrite in order to increase profits and minimize the environmental problem. Among these processes, bioleaching is a technique that uses microorganisms capable of obtaining energy from metal sulfides. In the specific case of chalcopyrite, the use of archaeas in low potential mediums for copper recovery has been very promising. This is because these potentials are capable of weakening chalcopyrite structure and increasing its solubilization. Thus, this work shows the use of Sulfolobus acidocaldarius archaea in the bioleaching of chalcopyritic concentrate in medium containing ferrous ions (0.200 mol L-1). The results were satisfactory around 86,6% of copper extraction after 110 days, demonstrating the potential of this microorganism to maintain low potential values and provide an efficient copper recovery even after a long time. Another added advantage was the high temperatures which further favored the process.
The increased use of copper with technological development has driven the search for alternative recovery methods. The largest natural source of this metal is chalcopyrite. However, due to its high refractoriness, it has economic applicability only through extraction by environmentally aggressive processes and with high financial contribution. In this context, we seek milder and cheaper processes for the recovery of this metal using chalcopyrite in order to increase profits and minimize the environmental problem. Among these processes, bioleaching is a technique that uses microorganisms capable of obtaining energy from metal sulfides. In the specific case of chalcopyrite, the use of archaeas in low potential mediums for copper recovery has been very promising. This is because these potentials are capable of weakening chalcopyrite structure and increasing its solubilization. Thus, this work shows the use of Sulfolobus acidocaldarius archaea in the bioleaching of chalcopyritic concentrate in medium containing ferrous ions (0.200 mol L-1). The results were satisfactory around 86,6% of copper extraction after 110 days, demonstrating the potential of this microorganism to maintain low potential values and provide an efficient copper recovery even after a long time. Another added advantage was the high temperatures which further favored the process.
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Palavras-chave
Calcopirita, Potencial redox, Sulfolobus acidocaldarius, Recuperação de cobre