Ettringite Induced Heaving and Shrinking in Kaolinite Clay

2007 ◽  
Author(s):  
Anand J. Puppala ◽  
Ekarin Wattanasanticharoen ◽  
Venkata S. Dronamraju ◽  
Laureano R. Hoyos
Keyword(s):  
Kaolinite Clay

scholarly journals Elucidation of Gram-Positive Bacterial Iron(III) Reduction for Kaolinite Clay Refinement

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3084
Author(s):  
Hao Jing ◽  
Zhao Liu ◽  
Seng How Kuan ◽  
Sylvia Chieng ◽  
Chun Loong Ho
Keyword(s):  
Iron Reduction ◽  
Growth Conditions ◽  
Cellular Interaction ◽  
Kaolin Clay ◽  
Media Composition ◽  
Gram Positive ◽  
Kaolinite Clay ◽  
Gram Positive Bacteria ◽  
Rich Media ◽  
The Media

Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field.

Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  
Keyword(s):  
Surface Area ◽  
Sulphuric Acid ◽  
Enzyme Immobilization ◽  
Morphological Changes ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Mineral Oxides ◽  
Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

Strength anisotropy in kaolinite clay

Géotechnique ◽  
1974 ◽  
Vol 24 (4) ◽  
pp. 674-678 ◽  
Author(s):  
R. Bhaskaran
Keyword(s):  
Strength Anisotropy ◽  
Kaolinite Clay

scholarly journals Red ceramics produced from mixtures of kaolinite clay and waste glass

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Emmanuel Tiffo ◽  
Antoine Elimbi ◽  
Joseph Dika Manga ◽  
Arlin Bruno Tchamba
Keyword(s):  
Waste Glass ◽  
Kaolinite Clay ◽  
Red Ceramics

Comparison of sorption of Pb2+ and Cd2+ on Kaolinite clay and polyvinyl alcohol-modified Kaolinite clay

Adsorption ◽  
2008 ◽  
Vol 14 (6) ◽  
pp. 791-803 ◽  
Author(s):  
E. I. Unuabonah ◽  
K. O. Adebowale ◽  
B. I. Olu-Owolabi ◽  
L. Z. Yang
Keyword(s):  
Polyvinyl Alcohol ◽  
Kaolinite Clay

Removal of Pb(II) from aqueous solution using modified and unmodified kaolinite clay

2009 ◽  
Vol 170 (1) ◽  
pp. 332-339 ◽  
Author(s):  
Ming-qin Jiang ◽  
Qing-ping Wang ◽  
Xiao-ying Jin ◽  
Zu-liang Chen
Keyword(s):  
Aqueous Solution ◽  
Kaolinite Clay

scholarly journals Comparative evaluation of properties of a clay based ceramic shaped via four techniques

Cerâmica ◽  
2018 ◽  
Vol 64 (370) ◽  
pp. 176-182 ◽  
Author(s):  
C. I. Torres ◽  
N. M. Rendtorff ◽  
M. Cipollone ◽  
E. F. Aglietti ◽  
G. Suárez
Keyword(s):  
Sintering Temperature ◽  
Continuous Process ◽  
Slip Casting ◽  
Textural Properties ◽  
Batch Process ◽  
Ceramic Ware ◽  
Kaolinite Clay ◽  
Qualitative And Quantitative ◽  
Quantitative Properties ◽  
Forming Methods

Abstract The results of qualitative and quantitative properties of clay based ceramic are presented in this work. Four different shaping methods and sintering temperatures were used to understand their influence in the final properties of a ceramic material formulated using kaolinite clay and calcined alumina. This material can be used as a structural ceramic for different applications, and there is no pre-established relation between the forming method and the final sintered properties. Forming methods used to prepare the samples were uniaxial pressing (a batch process that allows application in dry samples), extruding (a continuous process that requires moisture), slip casting (a process that allows to shape complex ceramic ware), and lamination (a batch process that requires moisture). Sintering temperatures were in the range of 1100 and 1400 °C. In order to compare how properties behave as the shaping method and sintering temperature change, textural properties, shrinkage, porosimetry, phase composition and mechanical strength were evaluated and analyzed. Scanning electron microscopy and microtomography were employed for analyzing and comparing the developed microstructures. Differences in the resulting properties are explained in terms of the developed crystalline phases and microstructure.

scholarly journals REMOVAL OF CU (II) FROM DYE EFFLUENT USING NATURAL AND PHOSPHATE-MODIFIED NIGERIAN KAOLINITE CLAY

2019 ◽  
Vol 7 (8) ◽  
pp. 402-414
Author(s):  
S. C. Olu ◽  
P. E. Dim ◽  
J. O. Okafor
Keyword(s):  
Free Energy ◽  
Metal Ion ◽  
Fourier Transforms ◽  
Lattice Structure ◽  
Enthalpy Change ◽  
Free Energy Change ◽  
Energy Change ◽  
Order Model ◽  
Acid Modification ◽  
Kaolinite Clay

This study indicates kaolinite clay as an effective adsorbent for the uptake of Cu (II) from wastewater. The adsorption process was studied with variation of time, temperature and adsorbent dosage at the effluent pH of 6. X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Brunauer Emmett and Teller (BET) and Scanning electron microscopy (SEM) were used to characterize the adsorbents. XRD spectra showed that modification with KH2PO4 did not significantly change the crystal spacing on the lattice structure of the clay mineral; however, there were shifts in the intensity of the peaks for the modified kaolinite clay. The FTIR spectra showed that certain functional groups are responsible for binding the metal ions from solution. SEM indicated an increase in the porosity of the modified adsorbent as compared with the unmodified kaolinite, which enhances metal ion adsorption on modified kaolinite clay. The BET indicate that acid modification increased the surface area and total pore volume of the kaolinite clay. The kinetic study revealed that the pseudo-first-order model fitted poorly to the equilibrium data, however, the pseudo-second-order model had a good fit for all reaction time at different initial concentrations. The mechanism of the sorption process was evaluated using thermodynamic properties such as enthalpy change (ΔH), Gibbs free energy change (ΔG), and entropy change (ΔS), which were evaluated using Van’t Hoff equations. The negative values of free energy change (ΔG), suggests spontaneity and feasibility of the process. The positive values of enthalpy change (ΔH) indicate endothermic nature of the process.

Sign in / Sign up

Export Citation Format

Share Document