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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

S?ntese de ze?litas a partir de um res?duo s?lico-aluminoso gerado na extra??o do l?tio do espodum?nio

Oliveira, Manuela Silva Martins de 05 August 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-20T21:21:26Z No. of bitstreams: 1 ManuelaSilvaMartinsDeOliveira_DISSERT.pdf: 4629063 bytes, checksum: 9e9e1aef7dcd4aa2529d87a665e32ac6 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-23T20:56:18Z (GMT) No. of bitstreams: 1 ManuelaSilvaMartinsDeOliveira_DISSERT.pdf: 4629063 bytes, checksum: 9e9e1aef7dcd4aa2529d87a665e32ac6 (MD5) / Made available in DSpace on 2017-02-23T20:56:18Z (GMT). No. of bitstreams: 1 ManuelaSilvaMartinsDeOliveira_DISSERT.pdf: 4629063 bytes, checksum: 9e9e1aef7dcd4aa2529d87a665e32ac6 (MD5) Previous issue date: 2016-08-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O l?tio ? um dos elementos que apresentam um elevado interesse comercial, justamente devido as suas caracter?sticas que possibilitam a utiliza??o em baterias de ?on l?tio, medicamentos, ligas, dentre outras aplica??es. Sua diversificada aplicabilidade aliada ?s dificuldades de obten??o faz com que esse material tenha um alto valor comercial. Um dos principais minerais de onde pode-se extrair l?tio ? o Espodum?nio. Industrialmente, o principal processo de obten??o do l?tio do espodum?nio ? a extra??o via ?cido sulf?rico. Tal processo gera como subproduto uma grande quantidade de res?duo s?lico-aluminoso que n?o possui destino final, sendo em sua maioria armazenados em aterros ou deixados ao ar livre. Foram estudados neste trabalho, diferentes procedimentos de s?ntese buscando diferentes estruturas zeol?ticas como uma maneira de agregar valor a este res?duo industrial. Seguiu-se como base a receita tradicional de cada estrutura fornecida pela ?International Zeolite Association? (IZA) modificando-a com a adi??o do res?duo s?lico-aluminoso. Os materiais sintetizados foram caracterizados atrav?s de difra??o de raios-X e microscopia eletr?nica de varredura (MEV). Foi poss?vel sintetizar ze?litas MER, EDI e MOR com alta cristalinidade e fase ?nica, sendo a primeira vez em que estas estruturas s?o obtidas atrav?s do res?duo s?lico-aluminoso proveniente da extra??o do l?tio do mineral espodum?nio. Outros materiais, tais como ze?lita LTA, foram obtidos, mas com pouca cristalinidade ou com mais de uma fase presente. Estudos complementares de otimiza??o desta s?ntese se fazem necess?rios. / Lithium is one of the elements that have a high commercial interest, precisely because of its features that allow use in lithium ion batteries, medicines, alloys, among other applications. Its diverse applicability allied to obtain difficulties makes this material has a high commercial value. One of the major minerals which can extract lithium is spodumene. Industrially, the main process of obtaining the spodumene lithium is extracted via sulfuric acid. This process generates as a byproduct a lot of silico-aluminous waste that has no final destination, being mostly stored in landfills or left outdoors. They were studied in this work, different synthetic procedures seeking different zeolite structures as a way to add value to this industrial waste. This was followed based on the traditional recipe of each structure provided by the "International Zeolite Association" (IZA) modifying it with the addition of silica-alumina residue. The synthesized materials were characterized by X-ray diffraction and scanning electron microscopy (SEM). It was possible to synthesize zeolites MER, EDI and MOR with high crystallinity and single phase, the first being that these structures are obtained by silico-aluminous waste from the extraction of the mineral spodumene lithium. Other materials, such as LTA zeolite, were obtained, but with low crystallinity or with more than one phase present. Further optimization studies are needed.

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