Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso
Autor(a) principal: | |
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Data de Publicação: | 2023 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/28959 |
Resumo: | Rare earth elements (REE) are a group of elements with very similar physical and chemical properties. They include the 15 elements of the lanthanide series (La–Lu), Y, and Sc. The need for these elements in different sectors of modern technology and the dependence on China has encouraged the search for secondary resources to obtain them. In this context, phosphogypsum, a waste generated in large amounts in phosphoric acid production, can be considered a promising alternative for obtaining REE. Therefore, this work aimed to evaluate the possibility of using phosphogypsum waste to obtain REE through conventional acid leaching and the process intensification through ultrasound-assisted leaching. Initially, the phosphogypsum waste was characterized regarding the chemical and nanomineralogical composition. The presence of several toxic elements in ultrafine particles and nanominerals was revealed, demonstrating the dangerous potential of this waste. In addition, REE at a concentration of about 5000 mg kg–1 was found, suggesting the high potential of phosphogypsum as a secondary source of these elements. From this, the recovery of REE was initially studied by conventional acid leaching. A leaching efficiency of 90% was achieved using a sulfuric acid concentration of 2.9 mol L−1 , solid/liquid ratio of 1.7/20 g mL−1 , and temperature of 55 °C. Under these conditions, the kinetic study showed that the equilibrium of the conventional leaching was reached in about 20 minutes. In sequence, the ultrasoundassisted leaching was investigated using an ultrasonic probe system. The optimization showed that a leaching efficiency of 84% was achieved using a sulfuric acid concentration of 0.6 mol L −1 , amplitude of 77%, and pulse of 93.6%, keeping set the solid/liquid ratio of 1.7/20 g mL−1 and temperature of about 40 °C. Under these same conditions, the leaching efficiency at silent condition was only 68%. The kinetic study demonstrated that the equilibrium of the ultrasound-assisted leaching was reached in about 20 minutes, while for the leaching at silent condition, the equilibrium was not verified within 60 minutes. These results demonstrated that the ultrasound could contribute to the REE leaching from phosphogypsum, leading to an increase of about 20% in the leaching efficiency and a considerable reduction in the time required to reach the equilibrium. According to the characterization results, the ultrasound effects on the REE leaching were mainly due to a large reduction in the particle size of the phosphogypsum. In summary, ultrasound was an effective method for the REE leaching from phosphogypsum, allowing obtaining a leaching efficiency comparable to that obtained in the conventional leaching, but using a sulfuric acid concentration about 5 times lower, thus representing a great advantage from the environmental point of view. |
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Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogessoConventional leaching and ultrasound-assisted leaching of rare earth elements from phosphogypsumCaracterização nanomineralógicaCinética de lixiviaçãoElementos terras rarasLixiviação ultrassônicaRecursos secundáriosValorização de resíduosNanomineralogical characterizationLeaching kineticsRare earth elementsUltrasonic leachingSecondary resourcesWaste valorizationCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICARare earth elements (REE) are a group of elements with very similar physical and chemical properties. They include the 15 elements of the lanthanide series (La–Lu), Y, and Sc. The need for these elements in different sectors of modern technology and the dependence on China has encouraged the search for secondary resources to obtain them. In this context, phosphogypsum, a waste generated in large amounts in phosphoric acid production, can be considered a promising alternative for obtaining REE. Therefore, this work aimed to evaluate the possibility of using phosphogypsum waste to obtain REE through conventional acid leaching and the process intensification through ultrasound-assisted leaching. Initially, the phosphogypsum waste was characterized regarding the chemical and nanomineralogical composition. The presence of several toxic elements in ultrafine particles and nanominerals was revealed, demonstrating the dangerous potential of this waste. In addition, REE at a concentration of about 5000 mg kg–1 was found, suggesting the high potential of phosphogypsum as a secondary source of these elements. From this, the recovery of REE was initially studied by conventional acid leaching. A leaching efficiency of 90% was achieved using a sulfuric acid concentration of 2.9 mol L−1 , solid/liquid ratio of 1.7/20 g mL−1 , and temperature of 55 °C. Under these conditions, the kinetic study showed that the equilibrium of the conventional leaching was reached in about 20 minutes. In sequence, the ultrasoundassisted leaching was investigated using an ultrasonic probe system. The optimization showed that a leaching efficiency of 84% was achieved using a sulfuric acid concentration of 0.6 mol L −1 , amplitude of 77%, and pulse of 93.6%, keeping set the solid/liquid ratio of 1.7/20 g mL−1 and temperature of about 40 °C. Under these same conditions, the leaching efficiency at silent condition was only 68%. The kinetic study demonstrated that the equilibrium of the ultrasound-assisted leaching was reached in about 20 minutes, while for the leaching at silent condition, the equilibrium was not verified within 60 minutes. These results demonstrated that the ultrasound could contribute to the REE leaching from phosphogypsum, leading to an increase of about 20% in the leaching efficiency and a considerable reduction in the time required to reach the equilibrium. According to the characterization results, the ultrasound effects on the REE leaching were mainly due to a large reduction in the particle size of the phosphogypsum. In summary, ultrasound was an effective method for the REE leaching from phosphogypsum, allowing obtaining a leaching efficiency comparable to that obtained in the conventional leaching, but using a sulfuric acid concentration about 5 times lower, thus representing a great advantage from the environmental point of view.Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPqOs elementos terras raras (REE, do inglês rare earth elements) formam um grupo de elementos com propriedades físicas e químicas muito semelhantes e compreende os 15 elementos da série dos lantanídeos (La–Lu), além do Y e do Sc. A criticidade desses elementos para diversos setores da tecnologia moderna e a dependência em relação à China tem incentivado a busca por fontes secundárias para obtenção dos mesmos. Nesse contexto, o fosfogesso, um resíduo gerado em grande quantidade na produção de ácido fosfórico, pode ser considerado uma alternativa promissora para a obtenção de REE. Portanto, o objetivo deste trabalho foi avaliar a possibilidade de utilizar resíduo de fosfogesso para obtenção de REE através de lixiviação ácida convencional, bem como avaliar a intensificação do processo através de lixiviação assistida por ultrassom. Inicialmente, o resíduo de fosfogesso foi caracterização quanto à composição química e nanomineralógica. Foi revelada a presença de diversos elementos tóxicos em partículas ultrafinas e nanominerais, demonstrando o potencial perigoso desse resíduo. Além disso, REE na concentração de cerca de 5000 mg kg–1 foram encontrados, sugerindo o grande potencial do fosfogesso como fonte secundária desses elementos. A partir disso, a recuperação de REE foi estudada inicialmente por lixiviação ácida convencional. Foi possível atingir uma eficiência de lixiviação de 90% usando uma concentração de ácido sulfúrico de 2,9 mol L−1 , razão sólido/líquido de 1,7/20 g mL−1 e temperatura de 55 °C. Nestas condições, o estudo cinético mostrou que o equilíbrio da lixiviação convencional foi atingido em cerca de 20 minutos. Em seguida, foi avaliada a lixiviação assistida por ultrassom usando um sistema de sonda ultrassônica. A otimização mostrou que foi possível atingir uma eficiência de lixiviação de 84% usando uma concentração de ácido sulfúrico de 0,6 mol L−1 , amplitude de 77% e pulso de 93,6%, mantendo fixa a razão sólido/líquido de 1,7/20 g mL−1 e uma temperatura de cerca de 40 °C. Nessas mesmas condições, a eficiência de lixiviação em condição de silêncio foi de apenas 68%. O estudo cinético demonstrou que o equilíbrio da lixiviação assistida por ultrassom foi atingido em cerca de 20 minutos, enquanto que para a lixiviação em condição de silêncio, o equilíbrio não foi verificado dentro de 60 minutos. Esses resultados demonstraram que o ultrassom foi capaz de contribuir para a lixiviação de REE a partir de fosfogesso, levando a um aumento de cerca de 20% na eficiência de lixiviação, bem como à uma redução considerável no tempo necessário para atingir o equilíbrio. De acordo com os resultados de caracterização, os efeitos do ultrassom na lixiviação de REE deveram-se principalmente a uma grande redução no tamanho das partículas de fosfogesso. Em resumo, o ultrassom foi um método eficaz para a lixiviação de REE a partir de fosfogesso, permitindo a obtenção de uma eficiência de lixiviação comparável com aquela obtida na lixiviação convencional, porém com o uso de uma concentração de ácido sulfúrico cerca de 5 vezes inferior, representando, portanto, uma grande vantagem de ponto de vista ambiental.Universidade Federal de Santa MariaBrasilQuímicaUFSMPrograma de Pós-Graduação em QuímicaCentro de Ciências Naturais e ExatasDotto, Guilherme Luizhttp://lattes.cnpq.br/5412544199323879Duarte, Fábio AndreiFranco, Dison Stracke PfingstenPinto, Luiz Antonio de AlmeidaCadaval Junior, Tito Roberto Sant’AnnaRosa, Marcelo Barcellos daLütke, Sabrina Frantz2023-05-04T13:50:47Z2023-05-04T13:50:47Z2023-02-28info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfhttp://repositorio.ufsm.br/handle/1/28959porAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2023-06-07T12:19:19Zoai:repositorio.ufsm.br:1/28959Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2023-06-07T12:19:19Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso Conventional leaching and ultrasound-assisted leaching of rare earth elements from phosphogypsum |
title |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso |
spellingShingle |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso Lütke, Sabrina Frantz Caracterização nanomineralógica Cinética de lixiviação Elementos terras raras Lixiviação ultrassônica Recursos secundários Valorização de resíduos Nanomineralogical characterization Leaching kinetics Rare earth elements Ultrasonic leaching Secondary resources Waste valorization CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso |
title_full |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso |
title_fullStr |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso |
title_full_unstemmed |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso |
title_sort |
Lixiviação convencional e lixiviação assistida por ultrassom de elementos terras raras a partir de fosfogesso |
author |
Lütke, Sabrina Frantz |
author_facet |
Lütke, Sabrina Frantz |
author_role |
author |
dc.contributor.none.fl_str_mv |
Dotto, Guilherme Luiz http://lattes.cnpq.br/5412544199323879 Duarte, Fábio Andrei Franco, Dison Stracke Pfingsten Pinto, Luiz Antonio de Almeida Cadaval Junior, Tito Roberto Sant’Anna Rosa, Marcelo Barcellos da |
dc.contributor.author.fl_str_mv |
Lütke, Sabrina Frantz |
dc.subject.por.fl_str_mv |
Caracterização nanomineralógica Cinética de lixiviação Elementos terras raras Lixiviação ultrassônica Recursos secundários Valorização de resíduos Nanomineralogical characterization Leaching kinetics Rare earth elements Ultrasonic leaching Secondary resources Waste valorization CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
topic |
Caracterização nanomineralógica Cinética de lixiviação Elementos terras raras Lixiviação ultrassônica Recursos secundários Valorização de resíduos Nanomineralogical characterization Leaching kinetics Rare earth elements Ultrasonic leaching Secondary resources Waste valorization CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
Rare earth elements (REE) are a group of elements with very similar physical and chemical properties. They include the 15 elements of the lanthanide series (La–Lu), Y, and Sc. The need for these elements in different sectors of modern technology and the dependence on China has encouraged the search for secondary resources to obtain them. In this context, phosphogypsum, a waste generated in large amounts in phosphoric acid production, can be considered a promising alternative for obtaining REE. Therefore, this work aimed to evaluate the possibility of using phosphogypsum waste to obtain REE through conventional acid leaching and the process intensification through ultrasound-assisted leaching. Initially, the phosphogypsum waste was characterized regarding the chemical and nanomineralogical composition. The presence of several toxic elements in ultrafine particles and nanominerals was revealed, demonstrating the dangerous potential of this waste. In addition, REE at a concentration of about 5000 mg kg–1 was found, suggesting the high potential of phosphogypsum as a secondary source of these elements. From this, the recovery of REE was initially studied by conventional acid leaching. A leaching efficiency of 90% was achieved using a sulfuric acid concentration of 2.9 mol L−1 , solid/liquid ratio of 1.7/20 g mL−1 , and temperature of 55 °C. Under these conditions, the kinetic study showed that the equilibrium of the conventional leaching was reached in about 20 minutes. In sequence, the ultrasoundassisted leaching was investigated using an ultrasonic probe system. The optimization showed that a leaching efficiency of 84% was achieved using a sulfuric acid concentration of 0.6 mol L −1 , amplitude of 77%, and pulse of 93.6%, keeping set the solid/liquid ratio of 1.7/20 g mL−1 and temperature of about 40 °C. Under these same conditions, the leaching efficiency at silent condition was only 68%. The kinetic study demonstrated that the equilibrium of the ultrasound-assisted leaching was reached in about 20 minutes, while for the leaching at silent condition, the equilibrium was not verified within 60 minutes. These results demonstrated that the ultrasound could contribute to the REE leaching from phosphogypsum, leading to an increase of about 20% in the leaching efficiency and a considerable reduction in the time required to reach the equilibrium. According to the characterization results, the ultrasound effects on the REE leaching were mainly due to a large reduction in the particle size of the phosphogypsum. In summary, ultrasound was an effective method for the REE leaching from phosphogypsum, allowing obtaining a leaching efficiency comparable to that obtained in the conventional leaching, but using a sulfuric acid concentration about 5 times lower, thus representing a great advantage from the environmental point of view. |
publishDate |
2023 |
dc.date.none.fl_str_mv |
2023-05-04T13:50:47Z 2023-05-04T13:50:47Z 2023-02-28 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufsm.br/handle/1/28959 |
url |
http://repositorio.ufsm.br/handle/1/28959 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Química UFSM Programa de Pós-Graduação em Química Centro de Ciências Naturais e Exatas |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Química UFSM Programa de Pós-Graduação em Química Centro de Ciências Naturais e Exatas |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
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UFSM |
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UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
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1805922097437868032 |