Extração de ferro de esmectita brasileira com emprego do método ditionito-citrato-bicarbonato

Leite, Sidnei Quezada Meireles; Colodete, Carlos Henrique A.; Dieguez, L.C.; Gil, Rosane A. S. San

doi:10.1590/s0100-40422000000300002

Cited by 12 publications

(6 citation statements)

References 11 publications

(22 reference statements)

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“…As shown by the results of X-rd (Figure 7), crystal plane spacing d = 3.34 Å (diffraction angle 2θ = 26.68) was the diffraction characteristic peak of SiO 2 , which is consistent with the reported characteristic peaks of quartz (SiO 2 ) structures (Leite et al, 2000;Marinoni and Broekmans, 2013). In this Figure, two peaks of CaCO 3 (2θ = 26.1 and 2θ = 27.1) were very high, hinting that the content of CaCO 3 was very high.…”

Section: Low Content Of Sio 2 In Shells With Spotssupporting

confidence: 86%

Silicon Dioxide (SiO2) Is the Most Important Component of Spots on the Inner Surface of Mactra veneriformis Shells

Zhang

Wei

et al. 2019

Front. Mar. Sci.

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Yellow-brown spots are often observed on the inner shell surface of the clam Mactra veneriformis sampled in Binhai New Area, Lijin County, Shandong Province, China, negatively impacting its commercial value. In this study, Scanning electron microscopyenergy dispersive spectroscopy (SEM-EDS), X-ray diffraction (X-rd), laser Raman spectrum (LRS), and Fourier infrared spectrum scanning (FT-IR) were used to detect and analyze the composition of spots on the inner shell surface of these clams. Compared with shells without spots, the shells with spots showed significant differences in their silicon contents but no differences in the content of other basic elements; LRS and X-rd examination revealed that, in addition to calcium carbonate particles, there were traces of silica bonds; after the removal of calcium carbonate by using hydrochloric acid, the spectral trend of particles was similar to that of sea sand, which was consistent with the spectral characteristics of SiO 2. Therefore, the spots on the inner shell surface of M. veneriformis are sea sand. These are likely to result from the increased sand content in seawater in the Yellow River Delta, whereby the grains of sand have fallen into the gap between the mantle and shell; thus, the sand becomes encased in the shells as they grow.

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Section: Low Content Of Sio 2 In Shells With Spotssupporting

confidence: 86%

Silicon Dioxide (SiO2) Is the Most Important Component of Spots on the Inner Surface of Mactra veneriformis Shells

Zhang

Wei

et al. 2019

Front. Mar. Sci.

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“…Verifica-se que a argila Verde Claro possui um alto teor de SiO 2 , provavelmente associado à presença de quartzo [25]. Todas as argilas apresentaram elevado teor de ferro, o que é característico das argilas do município de Boa Vista, PB e contribui para o abaixamento da temperatura de desidroxilação, diminuindo a estabilidade térmica do material [26]. As argilas também apresentaram alto teor de magnésio, mas um baixo teor de potássio.…”

Section: Resultsunclassified

Comportamento de expansão de argilas bentoníticas organofílicas do estado da Paraíba

et al. 2008

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Argilas organofílicas apresentam uma vasta gama de aplicações industriais, desde a indústria do petróleo à farmacêutica e de cosméticos, passando pela retenção de resíduos e produção de nanocompósitos argila-polímeros. Este trabalho tem por objetivo analisar a influência do teor de sais quaternários de amônio na organofilização de argilas bentoníticas. As argilas utilizadas foram caracterizadas através da determinação de sua composição química, distribuição do tamanho de partículas e capacidade de troca de cátions. As argilas organofílicas foram preparadas utilizando dois sais quaternários de amônio: cloreto de alquil benzil amônio (Dodigen) e brometo de cetil trimetil amônio (Cetremide). As argilas organofilizadas foram caracterizadas por difração de raios X e espectroscopia de infravermelho. Os resultados mostraram que o espaçamento basal aumenta com o aumento na quantidade de sal utilizado para a organofilização e que o comportamento desse aumento depende do sal e da argila utilizados, sendo, linear quando da utilização do sal Dodigen e dependente do tipo da argila quando da utilização do sal Cetremide.

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“…The natural clays have different compositions, and the presence of some types of minerals can frequently be a problem for some applications 7 . For example, in pillared clays for acid-base catalysis, the presence of Fe can reduce the thermal stability 8 . Acid treatments are efficient for removing Fe, but other cations, such as Ca, Mg and Na, can also be removed.…”

Section: Introductionmentioning

confidence: 99%

Acid treatments of montmorillonite-rich clay for Fe removal using a factorial design method

et al. 2013

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Montmorillonite clays are of great interest for industrial processes such as catalysis and adsorption. The textural properties of clays can be modified in an attempt to increase their uses. This paper describes the acid treatment of natural montmorillonite clay. The materials were characterized using X-ray diffraction (XRD), atomic absorption spectroscopy (AA) and BET surface area measurements. Three different acids (HCl, HNO 3 and H 2 SO 4 ) were tested, and HCl and H 2 SO 4 were more efficient for removing Fe from the clay. The results indicate that HCl better preserves the material structure because less Al is removed. A central composite design (CCD) 2 2 was applied to evaluate the treatment using /75 °C, assured that Fe was removed with less damage to the structure.

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Extração de ferro de esmectita brasileira com emprego do método ditionito-citrato-bicarbonato

Cited by 12 publications

References 11 publications

Silicon Dioxide (SiO2) Is the Most Important Component of Spots on the Inner Surface of Mactra veneriformis Shells

Silicon Dioxide (SiO2) Is the Most Important Component of Spots on the Inner Surface of Mactra veneriformis Shells

Comportamento de expansão de argilas bentoníticas organofílicas do estado da Paraíba

Acid treatments of montmorillonite-rich clay for Fe removal using a factorial design method

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