• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Estudo sobre tratamento t?rmico e mudan?a superficial da diatomita de Puna?/RN para o desenvolvimento de um auxiliar de filtra??o

Nascimento, Carlos Rener do 30 December 2013 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-10-14T12:07:35Z No. of bitstreams: 1 CarlosRenerDoNascimento_DISSERT.pdf: 10760871 bytes, checksum: 485a7679240639021e896c02d64ad53a (MD5) / Approved for entry into archive by Maria Maia (aniolly@bczm.ufrn.br) on 2015-10-14T12:39:56Z (GMT) No. of bitstreams: 1 CarlosRenerDoNascimento_DISSERT.pdf: 10760871 bytes, checksum: 485a7679240639021e896c02d64ad53a (MD5) / Made available in DSpace on 2015-10-14T12:39:56Z (GMT). No. of bitstreams: 1 CarlosRenerDoNascimento_DISSERT.pdf: 10760871 bytes, checksum: 485a7679240639021e896c02d64ad53a (MD5) Previous issue date: 2013-12-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / A diatomita ? um material natural que possui in?meras aplica??es devido ?s mudan?as nas suas propriedades f?sica e qu?mica ap?s processamento. Atualmente, ? utilizada na ind?stria como isolante ac?stico, auxiliar de filtra??o e carga industrial. O material filtrante deve apresentar composi??o qu?mica de material inerte, o que confere ? diatomita um alto valor comercial e desempenho, n?o encontrados em outros materiais particulados, para esta aplica??o. A diatomita sofre altera??es superficiais ap?s tratamento t?rmico em altas temperaturas, a partir de 800?C, apresentando propriedades que permitem sua aplica??o nas ind?strias aliment?cias, de bebidas, farmac?uticas, t?xteis e cosm?ticas. Neste trabalho, desenvolveu-se um estudo sobre tratamento t?rmico em diatomita natural a fim de adequar suas propriedades ? aplica??o como auxiliar de filtra??o. Os tratamentos t?rmicos foram realizados em forno aberto nas temperaturas de 800?C, 1000?C e 1200?C, por um tempo de 24 horas. Foram adicionados tamb?m reagentes na constitui??o das amostras em an?lise. Os reagentes usados foram, o carbonato de s?dio (Na2CO3) e o cloreto de s?dio (NaCl). As amostras foram caracterizadas por difra??o de raios-x, fluoresc?ncia de raios-x, microscopia eletr?nica de varredura, an?lise de distribui??o e tamanho de part?culas, ?rea superficial especifica pelo m?todo BET, e volume de poros pelo m?todo BJH. Os resultados mostraram uma redu??o na porosidade do material bem como um incremento significativo da ?rea superficial especifica ap?s tratamento t?rmico e com os reagentes na propor??o de 3% em peso. As diatomitas, ap?s tratamento t?rmico, sofreram altera??es na sua colora??o, variando nas cores branca, creme e bege, que interferem diretamente na velocidade do processo de filtra??o de materiais. Todos os resultados obtidos antes e ap?s tratamento t?rmico do material foram comparados aos valores obtidos para as amostras j?a usadas industrialmente, da ind?stria brasileira e americana, que foram caracterizadas atrav?s dos mesmos m?todos experimentais realizados com as amostras em estudo, e indicaram uma efici?ncia promissora ao material estudado da regi?o de Puna? - RN, ap?s seu processamento; adi??o de reagentes e tratamento t?rmico, como elemento na composi??o de filtrante. / The diatomite is a natural material that has numerous applications due to changes in their physical and chemical properties after processing. It is currently used in the industry as a sound insulator , filter aid and industrial load . The filter material shall be inert chemical composition , which will diatomite confers a high commercial value and performance not found in other particulate materials , for this application. The diatomite surface undergoes changes after thermal treatment at high temperatures , from 800?C , with properties that enable its application in the food , beverage , pharmaceutical , cosmetic and textiles . In this work , we developed a study on thermal treatment on natural diatomite to adapt their properties to the application as a filter aid . The heat treatments were performed in an open oven at temperatures of 800?C , 1000?C and 1200?C for a time of 24 hours. Reagents were added in the constitution of the samples analyzed. The reagents used were sodium carbonate (Na2CO3 ) and sodium chloride (NaCl) . The samples were characterized by x - ray diffraction , x -ray fluorescence , scanning electron microscopy , analysis and particle size distribution , specific surface area by the BET method , and pore volume by BJH method. The results showed a reduction in porosity of the material as well as a significant increase in specific surface area after heat treatment and the reactants in the ratio of 3 wt%. The diatomaceous earth , after heat treatment , undergone changes in its coloration , varying in white, cream and beige , which directly interferes with the speed of filtration materials process. All results obtained before and after heat treatment of the material with the values obtained for samples already used industrially , Brazilian and American industry , which were characterized using the same test methods performed with the samples in the study were compared and showed promising efficiency when material studied in the region of Puna? - RN , after processing , reagent addition and heat treatment, as an element in the composition of filter .

Page generated in 0.1242 seconds