Halloysite (Al2Si2O5(OH)4.2H2O) is a polymorphic kaolinite mineral whose predominant morphology is tubular. Due to this characteristic, halloysite is widely used in industrial applications, such as manufacture of silica- luminous catalysts, used for industrial chemical reactions; French porcelain; and the cracking of petroleum fractions into gasoline. Halloysite also has potential as a nanomaterial, particularly as an ingredient in polymer nanocomposites and as active agent for medical, agricultural, and other uses. This clay mineral occurs in a wide variety of geological environments as a product of alteration of rocks rich in sodium and potassium feldspars, such as intrusive acid rocks, granites, anorthosites, and pegmatites. This article characterizes halloysite and describes the treating process of kaolin- halloysite samples from four pegmatites, located in Porciúncula (Rio de Janeiro State) and Patrocínio do Muriaé (Minas Gerais State). The samples of the studied pegmatites were treated for mineralogical characterization and analyzed by X-ray diffractometry and scanning electron microscopy. Density, granulometry, and visual appearance of the grains were also analyzed. The samples were found to be composed of kaolinite/halloysite, feldspar, quartz, biotite, goethite and muscovite. Using X-ray diffractometry, gibbsite were also identified in one sample. With the results presented here, the two regions can be possible targets for researching halloysite deposits in the states of Rio de Janeiro and Minas Gerais.
Resumo-O contexto atual demonstra a necessidade de pensar a formação de professores para utilizar as Tecnologias Digitais de Informação e Comunicação (TDIC) na prática de sala de aula. Sendo assim, este trabalho objetivou investigar de que forma as TDIC estão sendo inseridas nos cursos de licenciatura em Matemática e Pedagogia para a formação de novos professores. Para tanto, foi realizada uma pesquisa qualitativa, de caráter exploratório, tendo como sujeitos da pesquisa seis professores que responderam a um questionário online. Os resultados foram obtidos por meio da análise do conteúdo e apontam que os professores fazem uso do celular no processo de ensino e aprendizagem, porém as práticas pedagógicas ainda estão focadas na perspectiva tradicional de ensino. A utilização pode ser viabilizada com base na formação continuada do uso ético e no respeito à privacidade dos professores.
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