Thermoelastic properties evolution and damping phenomena of Cameroonian calcined bauxite stabilized with calcium dialuminate refractory cement

Tchamba, Arlin Bruno; Elimbi, A.; Mbessa, Michel; Melo, Uphie Chinje; Nzegge, O.M.

doi:10.1016/j.ceramint.2014.07.133

Cited by 8 publications

(8 citation statements)

References 18 publications

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“…The aim of this study is to use the low‐grade bauxite to prepare mullite ceramics, investigate the effect of calcining temperature of raw bauxite on the mechanical properties of mullite ceramics, and explore the effect of the calcining temperature of raw bauxite on the sintering mechanism of mullite ceramics. The low‐grade bauxite need to be calcined before utilization because of its high contents of impurities . The main reason is that bauxite is calcined to remove the moisture and organics of bauxite enhancing the density of particles of raw material, reducing the porosity of materials, and improving the mechanical properties of ceramics.…”

Section: Introductionmentioning

confidence: 99%

Effect of the calcining temperatures of low‐grade bauxite on the mechanical property of mullite ceramics

Ren

et al. 2017

Int J Applied Ceramic Tech

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The mullite ceramics with excellent properties were prepared using traditional sintering method, and the starting material was low-grade bauxite without any other additives in this paper. The variations in physical and chemical properties in the process of sintering, the specific surface area of calcined bauxite at different calcining temperatures, and the phase composition of the mullite ceramic and its microstructure were investigated by thermal analysis, laser particle analysis, the X-ray diffraction, and scanning electron microscope, respectively. The effect of calcining temperatures of raw bauxite on mechanical property and sintering mechanism of mullite ceramic were explored and researched. The results showed that the flexural strength can reach 180 MPa, a great difference existed in mullite ceramics prepared from calcined bauxite at different calcining temperatures, and the sintering mechanism included densification of raw bauxite, the activities of calcined bauxite powders, and crystals in calcined bauxite. K E Y W O R D Sbauxite, calcining temperature, mullite, sintering mechanism

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Section: Introductionmentioning

confidence: 99%

Effect of the calcining temperatures of low‐grade bauxite on the mechanical property of mullite ceramics

Ren

et al. 2017

Int J Applied Ceramic Tech

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“…Quelques travaux de caractérisation pour d'éventuelles valorisations de ces matériaux ont été entrepris (Njoya et al, 2007;Tchamba et al, 2008;Njoya et al, 2010;Natatou et al, 2012;Sawadogo et al, 2014;Seynou et al, 2014;Sylla Gueye et al, 2016). Les bauxites font partie des ressources minérales naturelles les plus abondantes; et la demande de plus en plus croissante en matériaux alumineux justifie un nombre élevé des travaux de recherche portant sur les bauxites (McCormick et al, 2002 ;kahn et al, 2003 ;Xianxin et al, 2004 ;Tchamba et al, 2008 ;Tchamba et al, 2014 ;Tchamba et al, 2015 ;Njoya et al, 2016). La bauxite est un des minerais d'aluminium chimiquement composée de : Al 2 O 3 (> 40%), SiO 2 (2-20%), Fe 2 O 3 (20-35%), TiO 2 (2-4%), accessoirement P 2 O 5 (0,1-0,6%) (Wanchao et al, 2009 ;Gräfe et al, 2011 ).…”

Section: Introductionunclassified

“…Pour être économiquement rentable, un minerais de bauxite doit contenir au moins 40% Al 2 O 3 , moins de 8% SiO 2 et le rapport Al 2 O 3 /Fe 2 O 3 doit-être supérieur à 1. Les applications de la bauxite sont nombreuses et importantes surtout dans le domaine industriel, notamment dans : la production de l'aluminium, des réfractaires, des abrasifs, la composition du ciment et certains produits chimiques (sulfate d'aluminium), la fabrication des filtres, des supports catalytiques, des peintures, des émaux (Cemail, 2003 ;Liu et al, 2007 ;Smith, 2009 ;Gräfe et al,2011 ;Tchamba et al, 2015).…”

Section: Introductionunclassified

Caractérisation chimique et minéralogique de quelques indices de bauxite de Foumban (Ouest-Cameroun)

Njoya¹,

Njoya²,

Ngueteu³

et al. 2017

Int. J. Bio. Chem. Sci

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Chemical and mineralogical characterization of some bauxite indices from Foumban (West Cameroon) ABSTRACT Three samples labelled BF11, BF22 and BF33 from Foumban were subjected to chemical and mineralogical studies. The Al 2 O 3 content was found to be in the range 46.15-59.27% for the studied materials. The loss on ignition values are between 26.22 and 31.59%. The loss on ignition values and the Al 2 O 3 contents of these materials are similar to those of lateritic bauxites. The main mineral is gibbsite in samples BF11 (75.8%), BF22 (85.6%) and BF33 (67.7%) associated to kaolinite (3.3-8.4%), hematite in BF11 (5.7%) and BF33 (21.2%), anatase in BF33 (3.9%) and maghemite in BF22 (4.5%). The chemical and mineralogical composition makes them suitable for the production of aluminium and aluminium alloys, the production of refractories and the manufacture of cements.

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“…Well-grown crystalline of calcium dialuminate (CaO¨2Al 2 O 3 , or CA 2 ) with a very low coefficient of thermal expansion can be obtained at 1600˝C [2,3]. Although dense magnesium aluminate (MgO¨Al 2 O 3 , or MA) is difficult to fabricate at 1600˝C, it exhibits excellent mechanical, chemical, and thermal properties beneficial for the fabrication of cement rotary kilns, steel ladles, and glass furnace regenerators [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…Introducing CaO to substitute part of Al 2 O 3 in the alumina-rich zone of the Al 2 O 3 -MgO binary system decreases the mass and heat storage loss of the refractory, thereby producing a lightweight and energy saving Al 2 O 3 -MgO-CaO refractory [7]. According to the literature [2,8], the high aspect ratio of calcium hexaluminate (CaO¨6Al 2 O 3 , or CA 6 ) can strengthen the bond between CA 2 and MA grains because of the bridging mechanism. However, sintering CA 6 to full density even up to 1750˝C is difficult [9,10], causing its microstructures to become porous with around 20% porosity [11,12].…”

Section: Introductionmentioning

confidence: 99%

Effect of BaO Addition on Densification and Mechanical Properties of Al2O3-MgO-CaO Refractories

Liu

Chen

et al. 2016

Metals

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Considering the requirement for a reduction of refractory consumption, the present work investigated the fabrication of Al 2 O 3 -MgO-CaO-based refractory with BaO addition by means of solid-state reaction sintering. The effect of BaO addition on densification and the properties of the refractory were also discussed. Results indicated that the formation of calcium hexaluminate (CaO¨6Al 2 O 3 , or CA 6 ) grains with a high aspect ratio in the alumina-rich zone depressed the densification of the sample without BaO addition, resulting in a higher apparent porosity of 21.2%. When 6 wt. % BaO was added, a new phase of Ba 2 Mg 6 Al 28 O 50 (BAM) with a lower aspect ratio was formed and the densification of the sample with an apparent porosity of 5.52% was promoted. In addition, mechanical performance was significantly improved due to an increase in compactness and modification of the microstructure. The cold compressive strength increased from 348 MPa to 569 MPa and the flexural strength increased from 178 MPa to 243 MPa by addition of 6 wt. % BaO. Meanwhile, the breadth of the widest crack after the thermal shock test decreased from 7 µm to 1 µm in the refractory.

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Thermoelastic properties evolution and damping phenomena of Cameroonian calcined bauxite stabilized with calcium dialuminate refractory cement

Cited by 8 publications

References 18 publications

Effect of the calcining temperatures of low‐grade bauxite on the mechanical property of mullite ceramics

Effect of the calcining temperatures of low‐grade bauxite on the mechanical property of mullite ceramics

Caractérisation chimique et minéralogique de quelques indices de bauxite de Foumban (Ouest-Cameroun)

Effect of BaO Addition on Densification and Mechanical Properties of Al2O3-MgO-CaO Refractories

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