Characterization of Red Mud treated under high temperature fluidization

Nath, Harjeet; Sahoo, Pranati; Sahoo, Abanti

doi:10.1016/j.powtec.2014.09.011

Cited by 61 publications

(15 citation statements)

References 23 publications

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“…The total weight loss of RM was 15.55% of the total weight from 35 to 800 ∘ C, and the TG curve showed three weight loss steps. The first weight loss (5.21%) step occurred in the temperature range from 35 to 129 ∘ C, attributed to the evaporation of physically adsorbed water; the second step showed a rapid weight loss (6.82%) between 129 and 281 ∘ C which was ascribed to the removal of crystal water, partial decomposition of hydroxides, such as gibbsite decomposed into boehmite [28], and transformation of goethite to hematite [29]; the third weight loss (3.52%) step occurred in the temperature range from 281 to 800 ∘ C, which may be due to the decomposition of carbonate [30] and remaining hydroxides. The TG curve of the uncalcined MRM catalyst precursor showed three weight loss steps that were similar to those of RM, exhibiting that continuous weight loss was approximately 26.92% of the total weight from 22 to 800 ∘ C. The first weight loss of 8.52% from 22 to 130 ∘ C was mainly ascribed to the physically adsorbed water; the second weight loss of 12.29% from 130 to 364 ∘ C may be due to gibbsite and Fe hydroxide (formed in the homogeneous precipitation process during catalyst preparation) decomposed into -Al 2 O 3 [31] and hematite, respectively; the third weight loss of 6.11% in the temperature range from 364 to 800 ∘ C was attributed to decomposition of the remaining hydroxides.…”

Section: Resultsmentioning

confidence: 99%

A Nanomesoporous Catalyst from Modified Red Mud and Its Application for Methane Decomposition to Hydrogen Production

Fang

Liu

et al. 2016

Journal of Nanomaterials

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A type of nanomesoporous modified red mud (MRM) catalyst was prepared and utilized for catalytic methane decomposition (CMD) to produce hydrogen. The modification process significantly simplified the mineral composition of the red mud (RM); in the meantime, the physical and chemical structure of RM was changed. TEM images suggested that MRM was a kind of nanomesoporous material assembled by a number of uniformly nanoscale particles, BET results showed that the pore size distributions of MRM were ranged from 3 to 12 nm, and the specific surface area and total pore volumes of red mud improved from 8.00 m2/g and 0.08 cm3/g to 190.61 m2/g and 0.39 cm3/g, respectively. The catalytic performance of the catalysts has been tested at 800°C; the results showed that MRM exhibited much higher activity and stability than RM for CMD.

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Section: Resultsmentioning

confidence: 99%

A Nanomesoporous Catalyst from Modified Red Mud and Its Application for Methane Decomposition to Hydrogen Production

Fang

Liu

et al. 2016

Journal of Nanomaterials

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“…Bandas sobrepostas situadas na região de 1.000 cm -1 são atribuídas à deformação angular da ligação Al-O e Si-O. Em 530 e 470 cm -1 pode-se observar banda referente à ligação Fe-O de hematita e goethita [5,[34][35][36][37]. No estudo da morfologia dos materiais foi empregada a técnica de microscopia eletrônica de varredura (MEV).…”

Section: Figuraunclassified

Tratamento da lama vermelha com CO2 e ácido acético para aplicação em sistemasTipo Fenton e Fotocatálise

2019

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RESUMO A lama vermelha (LV_Nat) foi utilizada como matéria-prima para a preparação de dois materiais modificados com 1% (LV_1%) e 5% (LV_5%) de ácido acético. LV_Nat, LV_1% e LV_5% foram caracterizados (composição mineralógica, área BET específica, microscopia eletrônica de varredura, difração de raios X, espectroscopia XANES na borda-K do Fe, infravermelho (FTIR) e espectroscopia Mössbauer) e utilizados em testes catalíticos. Observou-se que o tratamento aumentou a área superficial da LV cerca de quatro vezes. Através de testes oxidativos realizados com azul de metileno (AM), verificou-se que o sistema mais adequado para ambos materiais foi o sistema Foto-Fenton, com 100% de degradação após 3 h de reação para LV_5% e após 4 h para a LV_1%. O ácido acético comportou-se como co-catalizador sendo muito efetivo, apresentando resultados observados com o uso de ácido orgânico equimolar com H2O2. A aplicação de lama vermelha modificada nos processos catalíticos oxidativos é uma alternativa atraente, que pode contribuir diretamente para o uso de resíduos orgânicos.

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“…The first weight loss (5.01%) step occurred in the temperature range from 35 to 124 ∘ C due to evaporation of physically adsorbed water; the second weight loss (7.46%) between 124 and 292 ∘ C was ascribed to the remaining crystal water, partial decomposition of hydroxides, such as gibbsite decomposed into boehmite [43], and transformation of goethite to hematite [44]. The final step occurred in the temperature range from 292 to 636 ∘ C, in which the weight loss was approximately 2.79% of the total weight, which may be attributed to decomposition of the remaining hydroxides and release of CO 2 during decomposition of carbonate [45].…”

Section: Xrd and Xrf Analyses Of Catalystsmentioning

confidence: 99%

Preparation of Modified Red Mud-Supported Fe Catalysts for Hydrogen Production by Catalytic Methane Decomposition

Liu

Fang

et al. 2017

Journal of Nanomaterials

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A modified red mud-(MRM-) supported Fe catalyst ( Fe/MRM) was prepared using the homogeneous precipitation method and applied to methane decomposition to produce hydrogen. The TEM and SEM-EDX results suggested that the particle sizes of the Fe/MRM catalysts were much smaller than that of raw red mud (RM), and the active metal Fe was evenly distributed over the catalyst structure. Moreover, BET results indicated that the surface areas and pore volumes of the catalysts were significantly improved, and the pore sizes of Fe/MRM were distributed from 5 to 12 nm, which is typical for a mesoporous material. The activities of those catalysts for the catalytic decomposition of methane were studied at atmospheric pressure at a moderate temperature of 650 ∘ C; the results showed that the Fe/MRM catalysts were more active than RM and MRM. The methane conversion curves of Fe/MRM catalysts exhibited similar variation tendencies (three-step) during the reaction despite different Fe contents, and the loading amount of Fe clearly affected the activity of the catalysts.

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Characterization of Red Mud treated under high temperature fluidization

Cited by 61 publications

References 23 publications

A Nanomesoporous Catalyst from Modified Red Mud and Its Application for Methane Decomposition to Hydrogen Production

A Nanomesoporous Catalyst from Modified Red Mud and Its Application for Methane Decomposition to Hydrogen Production

Tratamento da lama vermelha com CO2 e ácido acético para aplicação em sistemasTipo Fenton e Fotocatálise

Preparation of Modified Red Mud-Supported Fe Catalysts for Hydrogen Production by Catalytic Methane Decomposition

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