Mineralogical and Thermal Characterization of Kaolinitic Clays from Terra Alta (Catalonia, Spain)

Garcı́a-Vallés, Maite; Alfonso, Pura; Roca, Núria

doi:10.3390/min10020142

Cited by 53 publications

(53 citation statements)

References 44 publications

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“…The absence of smaller and thinner packets or sheaves crystals typical of hydrothermally altered kaolins further affirms the formation of these kaolins from weathering processes [51]. In addition, the absence of tubular-shaped crystals confirms the absence of halloysite in the kaolins [49,52]. Kaolinite crystal forms directly affect properties such as brightness, glossiness and printability in paper coating [44].…”

Section: Discussionmentioning

confidence: 56%

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Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications

2020

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The demand for kaolinitic clays for various industrial applications is increasing globally. The present study evaluated the potential industrial applications of kaolins from the Eastern Dahomey and Niger Delta Basins, Nigeria. The colour, pH, electrical conductivity (EC), particle size distribution (PSD), plastic limits and liquid limits of the kaolins were determined. Mineralogical properties were assessed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), and differential thermal analysis (DTA). The chemical compositions of the kaolins were determined using X-ray fluorescence spectrometry (XRF). The kaolins were generally acidic, with pH less than 7 with low EC. The moderate plasticity indices (PI ≥ 10%) for the kaolins suggested their potential use in the manufacturing of structural clay products without extrusion. Kaolinite was the only kaolin mineral present with anhedral–subhedral–euhedral crystals. The platy morphology of the kaolinites in the Cretaceous kaolins are very important in paper production. Other minerals present in the kaolins were quartz, muscovite, anatase and goethite. The major oxide contents of the kaolins were dominated by SiO2, Al2O3, Fe2O3 and TiO2. Based on chemical specifications, the raw kaolins are not suitable for most industrial applications except for the Cretaceous Lakiri kaolins in the paper and ceramic industries (except for TiO2 and K2O content). The study concluded that the kaolin deposits would require beneficiation for large-scale industrial applications.

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Section: Discussionmentioning

confidence: 56%

“…Weight losses accompanied by shrinkages due to exothermic and endothermic reactions in the kaolins have been reported [48]. Minimal shrinkage during firing of the kaolins as raw materials in ceramic processing is vital [47,49].…”

Section: Discussionmentioning

confidence: 99%

Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications

2020

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“…The raw kaolin reveals the piles of long flaky-like structure while having a rough surface. This is because the powder has a natural composition that causes various shapes and sizes which might adjust according to the preparation of the process [33]. The kaolin structure consists of sheets with visible edges of the pseudohexagonal habitus, which, when piled together, forms a smooth surface [34].…”

Section: Morphology Of Raw Kaolin and Acid Activated Metakaolinmentioning

confidence: 99%

Activation of Nano Kaolin Clay for Bio-Glycerol Conversion to a Valuable Fuel Additive

et al. 2021

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High production of biodiesel results in a surplus of glycerol as a byproduct that leads to a drastic decline in the glycerol price as well as overall biodiesel production. Alternative methods must be introduced for the economical process for biodiesel production via utilization of crude glycerol into valuable chemicals or fuel additives. This study introduces an ecofriendly process of solketal synthesis from glycerol and acetone in the presence of a novel metakaolin clay catalyst, which is a useful additive in biodiesel or gasoline, in order to enhance the octane number and to control the emissions. Moreover, kaolin clay catalysts are low cost, abundantly available, eco-friendly and one of the more promising applications for solketal synthesis. In this study, raw kaolin clay was activated with an easy acid activation technique, modification in physicochemical and textural properties were determined by using X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) and Field Emission Scanning Electron Microscope. Among all acid-treated catalysts, metakaolin K3 have shown best catalytic properties, high surface area and pore size after acid activation with 3.0 mol/dm3 at 98 °C for 3 h. Acetalization of glycerol with acetone carried out in the presence of an environmentally friendly and inexpensive novel metakaolin K3 catalyst. The maximum yield of solketal obtained was 84% at a temperature of 50 °C, acetone/glycerol molar ratio 6/1 and for 90 min with novel metakaolin clay catalyst. Effect of various parameters (time, temperature, acetone/glycerol molar ratio, catalyst loading) on the solketal yield and glycerol conversion was discussed in detail. This approach offers an effective way to transform glycerol into solketal—a desirable green chemical with future industrial applications.

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“…The lowest SiO2/ Al2O3 values corresponding to the white kaolinite levels and the highest Al2O3/Fe2O3 values corresponding to alumina-rich, with a certain whitish color. From an industrial point of view, the Al2O3/Fe2O3 mass ratio could be used to define the possible end uses of the clays in the ceramic paste formulation [54]. Due to its lower iron oxide content and SiO2/ Al2O3 mass ratio, and higher Al2O3/Fe2O3 mass ratio, beneficiated Debre Tabor kaolin is a suitable cheap raw material for developing ceramic membrane for water purification.…”

Section: Xrf Characterizationmentioning

confidence: 99%

“…%, and 0.16 wt. %, respectively which is attributed to the loss of surface, adsorbed/interlayer, and void water [54], [60], [61]. From 140 °C to 360 °C, a net weight gain of 0.062 wt.…”

Section: Dsc/tga Analysismentioning

confidence: 99%

Characterization and Beneficiation of Ethiopian Kaolin for use in Fabrication of Ceramic Membrane

Zewdie

Prihatiningtyas

Dutta

et al. 2021

Preprint

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Kaolin (china clay) is a rock material that is very rich in kaolinite. A kaolin ore from Debre Tabor, Ethiopia containing 59.2 wt.% SiO2, 24.9 wt.% Al2O3, 2.4 wt.% Fe2O3, and 8.22 wt.% loss on ignition (LOI) was physically beneficiated, chemically leached, and thermally treated for possible industrial use, especially for ceramic membrane fabrication. The leaching experiments were carried out using oxalic acid solutions as leaching reagents for the iron extraction process. The effect of acid concentration, reaction temperature, and contact time on iron leaching was investigated. It was determined that the rate of iron extraction increased with the oxalic acid concentration, leaching temperature, and contact time. A substantial reduction of iron oxide (2.4 to 0.36 wt. %) from the raw kaolin was observed at operating conditions of 2.0 M oxalic acid, the temperature of 120°C, and contact time of 120 min. A maximum kaolin whiteness index of 81.4 % was achieved through this leaching process. Finally, the physically beneficiated, chemically leached, and thermally treated kaolin raw material was used to fabricate a low-cost kaolin-based ceramic membrane. After firing at 1100°C the ceramic membrane was found to have a mass loss of 11.04 ± 0.05%, water absorption of 8.9 ± 0.4 %, linear shrinkage of 14.5 ± 0.05%. It was demonstrated to be chemically stable, having less than 3 % mass loss in acid solution, and less than 1 % mass loss in alkali solution. The newly developed membranes have thus properties comparable to commercial ceramic membranes.

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Mineralogical and Thermal Characterization of Kaolinitic Clays from Terra Alta (Catalonia, Spain)

Cited by 53 publications

References 44 publications

Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications

Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications

Activation of Nano Kaolin Clay for Bio-Glycerol Conversion to a Valuable Fuel Additive

Characterization and Beneficiation of Ethiopian Kaolin for use in Fabrication of Ceramic Membrane

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