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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Remo??o de carbonatos para otimizar a biolixivia??o de rejeito calcopir?tico empregando cons?rcio de microrganismos / Removal of carbonates in order to optimize the bioleaching of chalcopyrite tailings by employing consortium of microorganisms

Magalh?es, Vivian Maria de Arruda 28 January 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-22T15:37:57Z No. of bitstreams: 1 VivianMariaDeArrudaMagalhaes_DISSERT.pdf: 2346650 bytes, checksum: 8aef260736841bc9ac93307f974b2920 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-28T00:02:14Z (GMT) No. of bitstreams: 1 VivianMariaDeArrudaMagalhaes_DISSERT.pdf: 2346650 bytes, checksum: 8aef260736841bc9ac93307f974b2920 (MD5) / Made available in DSpace on 2016-07-28T00:02:14Z (GMT). No. of bitstreams: 1 VivianMariaDeArrudaMagalhaes_DISSERT.pdf: 2346650 bytes, checksum: 8aef260736841bc9ac93307f974b2920 (MD5) Previous issue date: 2016-01-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A biolixivia??o da calcopirita ainda n?o possui aplica??o em escala comercial devido ? baixa efici?ncia, por isso esse processo tem sido bastante estudado nos ?ltimos anos. A biolixivia??o de rejeito calcopir?tico se torna ainda mais dif?cil devido a presen?a de maior quantidade de impurezas, entre elas encontram-se os carbonatos. A presen?a de carbonatos no min?rio promove o aumento do pH da solu??o podendo inibir o desenvolvimento da biolixivia??o. Assim, essa pesquisa tem como objetivo a aplica??o do tratamento ?cido para otimiza??o do processo de biolixivia??o, a fim de recuperar o cobre perdido ao longo do processo al?m de reduzir o teor desse metal t?xico na lagoa de rejeitos. A remo??o e recupera??o de metais t?xicos ? grande relev?ncia na prote??o do meio ambiente e para sa?de dos seres humanos. Os experimentos de biolixivia??o foram realizados em duas etapas, na primeira fez-se uso do rejeito pr?-tratado com ?cido sulf?rico na biolixivia??o e na segunda fez-se uso do rejeito sem tratamento, com a adi??o de ?cido sulf?rico no in?cio da biolixivia??o. O tratamento ?cido foi realizado em biorreatores com a adi??o de tr?s volumes diferentes de H2SO4 96% e um experimento controle. Todos os experimentos de biolixivia??o foram realizados em triplicada mais um controle, sem adi??o de in?culo. Os resultados mostraram que o tratamento ?cido foi eficiente na remo??o dos carbonatos e conseguiu promover a biolixivia??o da calcopirita em ambas as etapas estudadas, sendo poss?vel atingir cerca de 47% de recupera??o de cobre ao final dos experimentos. / The bioleaching of chalcopyrite has not been applied on a commercial scale due to the low process efficiency, so this process has been extensively studied in recent years. The bioleaching of chalcopyrite tailings becomes even more difficult by the presence of higher amounts of impurities, among them are the carbonates. The presence of carbonates in the ore promotes the increase in pH of the solution and may inhibit the development of bioleaching. Therefore, this research aims to apply the acid treatment for optimization of bioleaching process, in order to recover the lost copper throughout the process besides reducing the content of this toxic metal in the tailings pond. The removal and recovery of toxic metals is very important in protecting the environment and human health. The bioleaching experiments were performed in two stages, the first made up using the pre-treated tailing with sulfuric acid in bioleaching, and the second was made using the tailing without treatment with sulfuric acid addition at the beginning of bioleaching. The acid treatment was carried out in bioreactors with three different volumes of H2SO4 96% and a control experiment. All bioleaching experiments were performed in triplicate over a control, without addition of inoculum. The results showed that acid treatment was effective in removal of carbonates and managed to promote a good performance in the bioleaching of chalcopyrite in both steps studied, it is demonstrated that circa 47% copper recovery can be achieved.

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