Showing papers in "Applied Clay Science in 2000"

TL;DR: Clays have been and continue to be one of the more important industrial minerals and are widely utilized in many facets of our society as mentioned in this paper.Clays and clay minerals are used in geology, agriculture, construction, engineering, process industries, and environmental applications.

TL;DR: In this paper, a general technique for the hydrothermal synthesis of clay minerals in the presence of organic, organometallic, and polymeric intercalants is described, along with their characterization and materials applications.

TL;DR: The flow behavior of sodium montmorillonite dispersions at salt concentrations below the critical coagulation concentration is determined by the influence of the ionic double layers on the mobility of the particles (secondary electroviscous effect) as mentioned in this paper.

TL;DR: In this paper, the authors reviewed the role of lichens on rocks and the biogeophysical and biogeochemical alteration of rock-forming minerals, their influence in dissolution and precipitation reactions and in bioformation of new minerals.

TL;DR: In this article, the effect of various organic acids viz. acetic, formic, citric, ascorbic, succinic, tartaric and oxalic acids on the iron removal and the resulting brightness improvement of an iron-stained kaolinitic clay from Kalliyur, Thiruvananthapuram, South India, has been investigated.

TL;DR: In this article, the capacity of the layered double hydroxides (LDHs) to react with the HCl formed during degradation of PVC was tested with respect to their ability to act as heat stabilizers.

TL;DR: Chimia et al. as discussed by the authors used X-ray photoelectron spectroscopy (XPS) to study the adsorption of Cs-, Ba-, Cu-, Zn-, and Pb-ions on the external surfaces of various, well characterized 2:1 layer silicates (micas and illites).

TL;DR: In this article, the adsorption and aggregation of a cationic cyanine dye, 1,1′-diethyl-2,2′-cyanine (pseudoisocyanine; abbreviated as PIC), on various clays have been investigated.

TL;DR: In this paper, a co-precipitation of M/Mg/Al hydrotalcite-type (HT) anionic clays (M2+/M3+ atomic ratio≈2.5, with the amount of M ranging from 0.04% to 5.0% (as atomic ratio) was successfully prepared by co-preserving in an aqueous solution at pH 10.0, although for the Pt-containing sample about 20% loss of the noble metal ions occurred.

TL;DR: In this article, Carara et al. compared the thermal properties of the pastes, prepared with these bentonites at different moisture, with the properties of a peloid, commonly used in the spa of Benetutti (northern Sardinia) using an experimental apparatus that reproduces the conditions during the application of a cataplasm.

TL;DR: In this paper, the chemical, mineralogical and technological properties of Sardinia bentonites, to identify the most suitable materials for pelotherapy pastes are reported, and the results of this study also show that a complete characterization of clay materials is necessary in pelotherapy paste preparation.

TL;DR: In this article, adsorption and desorption experiments were performed with I−, TcO4−, Cs+ and Sr2+ on MX-80 Wyoming-bentonite treated with hexadecylpyridinium (HDPy+) in amounts equivalent to 20% to 400% of the cation exchange capacity (CEC).

TL;DR: In this article, a complementary work concerning the modeling of gas pressure at the overpack-engineered barrier interface and its comparison with the clay gas breakthrough pressure was made possible by integrating the results of past and recent studies in this area.

TL;DR: In this article, the chemical and mineralogical properties of MX-80 bentonites were investigated by powder X-ray diffraction (XRD), by thermogravimetric (TG) and by calorimetric measurements and by IR spectral analysis.

TL;DR: In this article, synthetic mixed-layer mica/smectite samples were calcined at 560°C, 760°C and 960°C. Chemical, physical and mineralogical properties of both untreated and calcined samples, before and after being mixed with Ca(OH) 2 in the presence of simulated pore solution, were studied in detail.

TL;DR: In this paper, the structural and textural changes of the glauconite of Gafsa (Tunisia) reacted with boiling 3 M HCl solution were studied, and the porosity, specific surface and microporosity increased with activation time.

TL;DR: The Makoro kaolin is derived from the alteration of feldspathic arenites (arkose) that were deposited in a locally developed basin of Permian age as mentioned in this paper.

TL;DR: In this article, a series of reduced-charge montmorillonites (RCMs) was applied to NMR spectroscopies to detect changes in electronic and structural properties that are induced by Li fixation.

TL;DR: In a comparison of analytical methods in clay mineralogy, two clay samples (from Hennersdorf and Freydegg) of different clay composition were analyzed by 19 laboratories mainly by XRD as mentioned in this paper.

TL;DR: In this paper, anion adsorption on surfactant-modified clinoptilolite (SMC) was investigated, and two groups of SMCs could be distinguished: strong and weak anions.

TL;DR: In this article, the authors used X-ray diffraction (XRD) procedures for the identification of serpentine mineral mixtures, which is necessary for the rapid identification of the mixtures in remote sensing or portable field devices.

TL;DR: In this paper, a geographic distribution of clay minerals in UK Carboniferous coals is reflected in fly ash analyses and their properties, which may provide information on combustion mechanisms in coal combustion.

TL;DR: In this paper, the Freundlich adsorption isotherm describes 2,4-dichlorophenoxy propionic acid (2,4DP) sorption by organo-clays (Kf=1.828-11.474 l kg−1, nf=l.130-1.454, R=0.919-0.619, R = 0.71 nm).

TL;DR: In this article, the sintering at 1000°C of a clay raw material for pottery mixed with calcite was studied to increase the mechanical characteristics of the fired product.

TL;DR: In this article, metal exchanged amorphous kaolinite derivates were studied for their gas adsorption properties and the relationship between gas retention and various physical and chemical variables was investigated.

TL;DR: In this paper, the NH4-dominant sericite clays are chemically characterized by extensive substitution of NH4 for K corresponding to the muscovite-tobelite series, resulting in the basal spacing being enlarged from 10.00 A to 10.36 A.

TL;DR: In this paper, the acid properties of the final catalysts have been analyzed, and it was shown that the amount of clay in the final catalyst influences the initial activity and the product selectivity.

TL;DR: In this paper, the transport of the soluble salts contained in a compacted bentonite has been studied in a hydration and heating experiment, and the results show that the convective transport of salts, driven by the hydration, occurs in the presence of the thermal gradient.

TL;DR: In this paper, the processes affecting disordered kaolinites during hydrothermal treatment at 200°C, pH=4 and increasing time of reaction were studied, where the starting materials include untreated (natural), poorly ordered Georgia kaolinite (KGa-2), and this sample after intense grinding.