Thermal Treatment of Kaolin: Effect on the Pozzolanic Activity

Tironi, Alejandra; Trezza, Mónica Adriana; Irassar, Edgardo F.; Scian, Alberto N.

doi:10.1016/j.mspro.2012.06.046

Cited by 176 publications

(92 citation statements)

References 9 publications

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“…Elsewhere, this band was ascribed to the Al-OH bending mode of kaolinite [36], Al (VI) -OH vibrations [35], and Al (VI) -OH vibrations [39]. The band at 788 cm and beneficiated kaolinite, respectively, are given to the Si-O-Al (VI) where Al 3+ is in octahedral coordination [36,39,40]. When you compare the diagrams for both beneficiated and treated kaolinite, one can easily notice a total identity between them.…”

Section: Ft-irmentioning

confidence: 98%

Encapsulated Urea-Kaolinite Nanocomposite for Controlled Release Fertilizer Formulations

Sempeho¹,

Kim²,

Mubofu³

et al. 2015

Journal of Chemistry

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Urea controlled release fertilizer (CRF) was prepared via kaolinite intercalation followed by gum arabic encapsulation in an attempt to reduce its severe losses associated with dissolution, hydrolysis, and diffusion. Following the beneficiation, the nonkaolinite fraction decreased from 39.58% to 0.36% whereas the kaolinite fraction increased from 60.42% to 99.64%. The X-ray diffractions showed that kaolinite was a major phase with FCC Bravais crystal lattice with particle sizes ranging between 14.6 nm and 92.5 nm. The particle size varied with intercalation ratios with methanol intercalated kaolinite > DMSO-kaolinite > urea-kaolinite (KPDMU). Following intercalation, SEM analysis revealed a change of order from thick compact overlapping euhedral pseudohexagonal platelets to irregular booklets which later transformed to vermiform morphology and dispersed euhedral pseudohexagonal platelets. Besides, dispersed euhedral pseudohexagonal platelets were seen to coexist with blocky-vermicular booklets. In addition, a unique brain-form agglomeration which transformed into roundish particles mart was observed after encapsulation. The nanocomposites decomposed between 48 and 600 ∘ C. Release profiles showed that 100% of urea was released in 97 hours from KPDMU while 87% was released in 150 hours from the encapsulated nanocomposite. The findings established that it is possible to use Pugu kaolinite and gum arabic biopolymer to prepare urea CRF formulations.

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Section: Ft-irmentioning

confidence: 98%

Encapsulated Urea-Kaolinite Nanocomposite for Controlled Release Fertilizer Formulations

Sempeho¹,

Kim²,

Mubofu³

et al. 2015

Journal of Chemistry

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“…The TG curve of M1A3 microspheres showed mass loss stages before 700°C obviously, which could be attributed to the evaporation of free water (RT‐135°C), loss of coordinated water (135‐470°C), constitution water (470‐700°C) of palygorskite and combustion of carbon and organic matters during the heating process (Figure A). As for the DTA curves, the endothermic peak presented at 540°C ranged from 400 to 600°C, was mainly due to the dehydration of −OH groups of the kaolinite phase surface and formation of metakaolin, as described by the following reaction Equation 3 . The intensity of the exothermic peak at 650°C was increased with the gangue/palygorskite content in the microspheres, which was attributed to the consumption of carbon and organics(Figure B).…”

Section: Resultsmentioning

confidence: 86%

Low‐cost, green synthesis and adsorption properties for dyes of novel porous gangue/palygorskite composite microspheres

Yan

Wang

Zhang

et al. 2019

Int J Applied Ceramic Tech

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In this work, gangue/palygorskite composite microspheres were fabricated through spray drying process and activated by calcination treatment. Its microstructure and adsorption capacity for the removal of dye (MB) were also studied, systematically. Results showed that kaolinite, α-quartz and palygorskite were the major phases in microspheres after proper calcination (lower than 900°C). BET-specific surface area of the microspheres reached the maximum value of 62.23 m 2 /g at 700°C, and then decreased with further increasing the heating temperature. In general, composite microspheres showed the largest adsorption capacity of MB after heat-treated at 700°C. The q max of MB onto microspheres was 29.9-51.9 mg/g. The adsorption process of MB onto microspheres was well described by both the pseudo-second-order kinetic and Langmuir isotherm model. The composite microspheres also had extraordinary recyclability. This novel microsphere could be employed as a candidate for novel absorbent and filter medium in the practical application for dye treatment in industrial applications.

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“…Presence of absorption bands at 3690 cm −1 Fig. 1 XRD pattern of Pugu kaolin corresponds to outer OH group while that at 3620 cm −1 is due to bonded molecular water [36].…”

Section: Characterization Of Kaolinmentioning

confidence: 98%

Preparation of aluminium sulphate from kaolin and its performance in combination tanning

et al. 2019

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Leather making commonly use chromium salts to produce high quality products. However, the use of chromium salts is compromised by environmental safety concerns. Combination tanning using vegetable tanning coupled with aluminium sulphate can sustainably replace chrome tanning system. Adversely, the use of commercial aluminium sulphate poses economic burden that entails for cost effective sources. Abundance of kaolin on earth's crust with scarce utilization is an opportunity towards cost effective aluminium sulphate for tanning. Therefore, in the present work aluminium sulphate was prepared from kaolin and its performance for combination tanning was studied. Diffraction and vibrational spectroscopic studies were carried out to confirm the prepared aluminium sulphate. Combination tanning was carried out with mimosa vegetable tannins. Leathers tanned with the combination of aluminium sulphate from kaolin and mimosa vegetable tannin exhibited hydrothermal stability of up to 118 °C as compared to mimosa alone that showed the average of 80 °C. Physical strength characteristics met the standard norms. Fibers separation was good as confirmed through microscopic studies. The study provides a new insight on accomplishing self-sustenance through available resources and eco-friendly manufacturing system.

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Thermal Treatment of Kaolin: Effect on the Pozzolanic Activity

Cited by 176 publications

References 9 publications

Encapsulated Urea-Kaolinite Nanocomposite for Controlled Release Fertilizer Formulations

Encapsulated Urea-Kaolinite Nanocomposite for Controlled Release Fertilizer Formulations

Low‐cost, green synthesis and adsorption properties for dyes of novel porous gangue/palygorskite composite microspheres

Preparation of aluminium sulphate from kaolin and its performance in combination tanning

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