Modifications induced by the thermal treatment of kaolin and determination of reactivity of metakaolin

Fabbri, B.; Gualtieri, Sabrina; Leonardi, Chiara

doi:10.1016/j.clay.2012.09.019

Cited by 128 publications

(62 citation statements)

References 11 publications

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“…Soaking of a mass of 1.5 kg of K at 700 • C in an electric muffle furnace on ceramic plates (Nabertherm Mod LH 60/14) lasted 30 min at the following rates of calcination: 1 • C/min, 2.5 • C/min, 5 • C/min, 10 • C/min, 15 • C/min and 20 • C/min. The obtained metakaolins were respectively labeled as MK 1 , MK 2.5 , MK 5 , MK 10 , MK 15 and MK 20 .…”

Section: Materials Processingmentioning

confidence: 99%

“…Demolding was carried out 24 h later and the cubic samples were covered with polyethylene film and stored at ambient temperature (20 ± 2 • C) under 98% RH condition for 28 days. According to the rate of calcination of kaolin, the cubic geopolymer specimens were respectively labeled as GPC 1 , GPC 2.5 , GPC 5 , GPC 10 , GPC 15 and GPC 20 . The cubic specimens aged of 28 days were subjected to compressive strength using an automatic electro-hydraulic press (IGM) operating at an average rate of 0.2 kN/s.…”

Section: Paste and Concrete Samples Preparation And Analytical Technimentioning

confidence: 99%

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Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers

Diffo

Elimbi

Cyr

et al. 2015

Journal of Asian Ceramic Societies

129

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Please cite this article in press as: B.B. Diffo Kenne, et al., Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers, J. Asian Ceram. Soc. (2014), http://dx. a b s t r a c tKaolin samples of the same mass were treated at 700 • C for the same duration of 30 min by varying the rate of calcination (1, 2.5, 5, 10, 15 and 20 • C/min) in order to obtain metakaolins which were used to produce geopolymers. Depending on the nature of each type of material, kaolin, metakaolins and geopolymers were characterized using thermal analysis, chemical analysis, XRD, FTIR, particle size distribution, specific surface area, bulk density, setting time and compressive strength. FTIR and XRD analyses showed that metakaolins except at 1 • C/min contained residual kaolinite whose quantity increased with the rate of calcination of kaolin and which influenced the characteristics of geopolymers. Thus as the rate of calcination of kaolin increased, the setting time increased (226 min (rate of 1 • C/min)-773 min (rate of 20 • C/min)) while the compressive strength reduced (49.4 MPa (rate of 1 • C/min)-20.8 MPa (rate of 20 • C/min)). From the obtained results the production of geopolymers having high compressive strength along with low setting time requires that the calcination of kaolin be carried out at a low rate.

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Section: Materials Processingmentioning

confidence: 99%

Section: Paste and Concrete Samples Preparation And Analytical Technimentioning

confidence: 99%

Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers

Diffo

Elimbi

Cyr

et al. 2015

Journal of Asian Ceramic Societies

129

View full text Add to dashboard Cite

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“…Calcination promotes the dehydroxylation of kaolinite and thus a change in the environment around the aluminum atoms, which begin to acquire coordination numbers 4 and 5 12 . Thus, the octahedral aluminum starts to become tetrahedral, making the material amorphous and more reactive.…”

Section: Resultsmentioning

confidence: 99%

Study on the NaOH/metakaolin Ratio and Crystallization Time for Zeolite a Synthesis from Kaolin Using Statistical Design

et al. 2017

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The NaOH/metakaolin ratio and crystallization time were studied for the synthesis of zeolite NaA from a sample of kaolin from a Capim mine. The tests were carried out by using statistical design with axial points and replication of the central point. The samples obtained were characterized by X-ray diffraction (DRX), scanning electron microscopy and chemical analysis using a microprobe EPMA. The results showed that there is a relationship between the amount of NaOH added and crystallization time. The tests carried out using the lowest NaOH/metakaolin ratio (0.5) and the shortest time (4 h) produced a non-crystalline material. On the other hand, increasing the NaOH/metakaolin ratio and the crystallization time led to the formation of a NaA phase with a high structural level, but with the presence of a sodalite phase as an impurity.

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“…As shown, only kaolin and talc phases are detected in the ceramic foam green body. The diffraction peaks at 2θ of 12.5, 21.0, 25.0, 39.4 and 62.4° correspond to kaolin [17] (Kaolinite, Al 2 Si 2 O 5 (OH) 4 , ICDD PDF 14-0164), while other ones at 28.5, 36.0 and 38.5° are indexed to talcum powder (Talc, Mg 3 Si 4 O 10 (OH) 2 , ICDD PDF 13-0558). When the calcination temperature increases to 1 150 ℃, the diffraction peaks of cristobalite, corundum and sillimanite occur, in the absence of kaolin and talc.…”

Section: Characterizationmentioning

confidence: 98%

“…Accordingly, a weight loss of 3.99% is given. At 503.6 ℃, there is a sharp endothermic peak corresponding to the dehydroxylation of kaolin, and a shoulder is also appreciated in the TG curve [17,18] . The weight loss at this stage is about 10.08% which is comparable to the content of the bound water in kaolin (Al 2 Si 2 O 5 (OH) 4 →Al 2 Si 2 O 7 +2H 2 O).…”

Section: Characterizationmentioning

confidence: 99%

Preparation of ceramic foams suitable for aircraft arresting by the airport runway based on a protein foaming agent

Zhang

Zhou

Yang

et al. 2014

J. Wuhan Univ. Technol.-Mat. Sci. Edit.

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Crushable ceramic foams are more suitable to be used as an arrestor material applied in engineered materials arresting system (EMAS) for airport runway for their properties of widely controllable strength, negligible crushing-rebounding behavior, durability, and chemically-inert composition, comparing with traditional concrete foams. The synthesis of ceramic foams adopted direct-foaming method and used an animal protein as foaming agent. Kaolin, talc powder and alumina were the main raw materials. Effects of the ratios of raw materials, calcination temperatures, heating rates, holding time, viscosities of polyvinyl alcohol (PVA) solution as well as the amounts of protein foaming agent and water on microscopic structure, densities, compressive strength and open porosities of ceramic foams were investigated systematically. The results indicate that ceramic foams with typical pore sizes 100-300 μm, open porosities from 73.1% to 91.5%, densities from 0.25 to 0.62 g·cm 3 , compressive strength from 0.19 to 4.89 MPa, are obtained by properly adjusting the parameters mentioned above. And the mechanical strength meets the requirement for the EMAS for airport runway. In addition, good correlations are observed among compressive strength, open porosity, microscopic structure, and crystal phase. Furthermore, the possibility of producing the general dimensions of such aircraft arresting components with the proposed method was also discussed.

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Modifications induced by the thermal treatment of kaolin and determination of reactivity of metakaolin

Cited by 128 publications

References 11 publications

Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers

Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers

Study on the NaOH/metakaolin Ratio and Crystallization Time for Zeolite a Synthesis from Kaolin Using Statistical Design

Preparation of ceramic foams suitable for aircraft arresting by the airport runway based on a protein foaming agent

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