Showing papers in "Applied Clay Science in 1997"

TL;DR: In this paper, a method for the rapid determination of CEC values in clays using au ethylenediamine complex of Cu was tested with different clays and the results were generally in good agreement with those given by the classical Kjeldahl method.

TL;DR: In this paper, an acid activation with HCl of two bentonites from the Aegean Islands of Milos and Chios, Greece, consisting of Chambers and Tatatilla-type and Otay-type montmorillonite, respectively, resulted in a 4 to 5-fold increase of the surface area of the raw materials.

TL;DR: In the 21st century the emphasis in exploration will be in the developing nations, and the level of sophistication in exploration methods will increase as discussed by the authors, and the trends are towards finer particle size, higher purity and surface modification to both permit their more specialized application in industry and to resist the challenges from other natural and synthetic minerals.

TL;DR: In this article, the effect of micronization on the crystalline structure of kaolinite clay mineral and the role of mechanically modified Kaolinite structure on the adsorption/ion-exchange properties of toxic heavy metals are discussed.

TL;DR: The effect of dry grinding on the structure, particle size and shape of talc from Puebla de Lillo (Leon, Spain) was studied by means of nitrogen adsorption, XRD, DTA-TG and by SEM-EDS methods.

TL;DR: In this paper, a series of laboratory direct shear tests were conducted to evaluate the effects of different freezing conditions at the shearing plane, on the shear strength of the thawing clayey soils.

TL;DR: In this article, a bentonite was modified to zeolitic material by alkaline treatment in distilled and seawater media using two different methods: a reflux system and in an autoclave.

TL;DR: In this article, different pillaring species (Al, Ti, Zr, Fe) were investigated and discussed in terms of pore volume, pore size and pore distribution.

TL;DR: The Sardinian ceramic industry produces structural clay products (common and hollow bricks). The raw materials are obtained from Tertiary continental sediments (Cixerri, Ussana and Samassi Formations) found in the south-western part of the island as mentioned in this paper.

TL;DR: In this article, three different grades of Korean natural zeolites which contained clinoptilolite or both clinoptile and mordenite were treated with 2 M NaOH solution at 103°C during different times ranging from 1 to 16 h.

TL;DR: In this article, the authors discuss ways to improve the brightness of zeolite 4A prepared from kaolin by the removal or masking of iron minerals at various levels of the process route.

TL;DR: In this paper, three methods (i) a classical "dilute suspension and solution" method by adding the nitrate pillaring solution to a 2% clay suspension, (ii) a 'powder in solution' method where the clay powder is dispersed in the pillararing solution and (iii) a ''concentrated slurry'' method in which a dialysis bag containing clay-water slurry (33% w/w) is placed in the solution.

TL;DR: The soil map of Thailand has been used to define the clay mineral provinces as mentioned in this paper, which can be divided into five regions: the northern, central, north-east, south-east coast and peninsular region.

TL;DR: In this article, the effects of particle morphology on the rheological behavior of high-solids kaolin suspensions were investigated using low shear (Brookfield) and high-shear (Hercules) viscometers.

TL;DR: In this paper, a trip was made to both the type locality and adjacent abandoned mining sites to seek information about the origin of the name kaolin and related kaolinite and its origin in the Dazhou mining area was studied by optical microscopy, XRD, TEM, SEM, EDS and isotopic analysis.

TL;DR: In this paper, the potential expansiveness of clays in Poland is evaluated based on the indirect methods described by Van der Merwe (1964) and Seed et al. (1962) nomograms.

TL;DR: The Romana kaolins represent the alteration products of rhyolite-rhyodacite Oligocene volcanics from SW Sardinia, Italy as discussed by the authors, and they can be used to manufacture vitrified tiles or sanitaryware; they should be added to the body in partial replacement of the quartz-rich kaolinitic clays currently used in the Italian ceramic industry.

TL;DR: In this paper, the effect of applied compactive energy on the shear strength, permeability and swelling pressure of compacted cohesive soil at constant water content was investigated and it was found that for a given water content on the dry side of the optimum water content, increasing the compulsive energy has a small or no effect on the unconfined compressive strength when the water content of the soil is above the optimum.

TL;DR: In this article, a study of the acidity of surface groups showed that the Al13 polycation is transformed into a specific form of Al oxyhydroxide with amphoteric properties, which may be interpreted by the existence of surface species of type AlOH(OH2), having two constants of depronation Ka1 = 10−5 and Ka2 = 0.32 · 10−6.

TL;DR: The geology and genesis of three kaolin deposits (Las Mellizas, Chita and Misud) located in the Neuquen basin were studied in this article, where they were exploited to make stoneware products.

TL;DR: The halloysite clay deposit from the locality of Farbani Potok, Iran, containing over 95% of the mineral halloyite, was investigated in this paper, and the activation energy of dehydroxylation was determined as 169 kJ mol −1 while the value for mullitization was 715 kJmol −1.

TL;DR: In this paper, a set of non-equilibrium irreversible thermodynamics and assuming an isotropic porous system, the macroscopic laws of conservation and the liquid-vapor equilibrium relation of the green clay brick was developed for the prediction of simultaneous mass and heat transfer (luring the drying process).

TL;DR: In this paper, the oxidation of 2,6-dimethylphenol and o -methylphenol by Na + -, Ca 2+ -, Al 3+ - and Fe 3 + -saturated montmorillonite with pH values varying between 2 and 12.

TL;DR: In this article, the experimental X-ray powder diffraction patterns have been compared with simulated diffractograms from structure refinement data for the triclinic and monoclinic talcs.

TL;DR: In this article, the authors showed the advantages of the use of baked clay support media for biomass retention in the treatment of food industry wastewaters by anaerobic filters, which reduced the chemical oxygen demand by up to 97.5%.

TL;DR: The Santonian sandy-clayey sediments of the North Sudetic Trough (Lower Silesia, Poland) are exploited as kaolinite raw materials.

TL;DR: In this paper, an exploration program located kaolinite and halloysitic clays of potential commercial significance on the Coromandel Peninsula east of Auckland, New Zealand have been argillized by subtropical weathering and hydrothermal activity.

TL;DR: In this article, the authors classified the deposits of these kaolinite-rich plastic clays into four types: complex tectonic basins, interactive multi-basin deposits, large lens deposits and recent lenses.

TL;DR: In this paper, the authors studied the flow properties of dilute Na montmorillonite suspensions and showed that the consistency curves of these suspensions may exhibit a different behavior from that of a perfect Newtonian fluid with a concentration of 33-36 kg/m 3.

TL;DR: In this article, the authors proposed a new strategy for clays that has to respect distinct quality requirements of different users and manufactured products, and simplification of sampling and analytical strategy is required.