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The x-ray identification and crystal structures of clay minerals

01 Jan 1961-
About: The article was published on 1961-01-01 and is currently open access. It has received 966 citations till now. The article focuses on the topics: Clay minerals.
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TL;DR: In this article, 5% high viscous glass was used along with china clay and the results regarding the oxidation behaviour of SIC and mechanical properties of the sintered compacts were compared with those of the compositions without glass.
Abstract: Difficulty in consolidation of SiC, particularly at a lower temperature and in ambient atmosphere, necessitates the use of second phase bonding materials like clay and other aluminosilicates. In such systems, oxidation of SiC is difficult to control and it goes on until substantial amount of glassy phase is formed which protects individual SiC grains from further oxidation. A high viscosity glass if used for the initial bonding of SiC grains along with a second phase material like clay, the above difficulties could be overcome. In the present investigation, 5% high viscous glass was used along with china clay and the results regarding the oxidation behaviour of SIC and mechanical properties of the sintered compacts were compared with those of the compositions without glass.
29 Mar 2013
TL;DR: The upper Cretaceous Lokoja Formation of southern Niger Basin in Nigeria as discussed by the authors is a dominantly sandy facies comprising of two distinctive members, the lokoja and Patti Siltstone, which are petrologically defined as dominantly poorly sorted angular to sub-angular, fine to aly skewed, immature lithic arkose to sublitharenite with a detrital clayey matrix of over fifteen percent.
Abstract: The Upper Cretaceous Lokoja Formation of southern Niger Basin in Nigeria is a dominantly sandy facies comprising of two distinctive members, the Lokoja and Patti Siltstone. The fluvial sandstone of the Lokoja Sandstone is petrologically defined as dominantly poorly sorted angular to sub-angular, fine to aly skewed, immature lithic arkose to sub-litharenite with a detrital clayey matrix of over fifteen percent (15%). The dominantly silty, marine to fluvial sediments of the Patti Siltstone is defined as massive, moderately sorted, sub-angular to sub-rounded, averagely fine skewed and minerologically mature but texturally immature quartz arenite. The quantitative analyses of light, heavy and clay fractions of sandstone samples from the Lokoja Formation also showed variation and made possible to group these sediments as lower and upper mineralogical units. A southwest terrain (basement rocks) with a peneplain topography that had relatively warm and humid tropical palaeoclimate served as the source of detrital materials for the Lokoja Sandstone whose deposition was rapid following a diastrophic movement (folding and faulting) in the continent. The Patti Siltstone sediments were derived from rapid erosion that characterized an area of high relief (crystalline West Africa basement rocks) with warm and tropical alkaline environment generating a uniform debris supply at slower but continuous rate of deposition.
Journal ArticleDOI
TL;DR: In this article, a series of electron microscopic studies was carried out to make clear the surface fine structure of clay coated papers and it was found that their fine structure depends largely upon the shape and size of clay particles.
Abstract: A series of electron microscopic studies was carried out to make clear the surface fine structure of clay coated papers. The present work forms part of those studies and deals mainly with coating clays. The clays used are kaolin, sericite, roseki-clay and hydrated halloysite and were coated on a stock paper by using casein as a binder. The results obtained are as follows : (1) The one stage replica method, which was carried out by evaporating carbon an leaf, was found to be the most suitable technique for the purpose of this case. (2) The surface of clay handcoated papers was observed to consist of the clay layers parallel to paper surfaces. And it was found that their fine structure depends largely upon the shape and size of clay particles. (3) By comparing the surface of non-supercalendered coated papers with those of supercalendered coated papers, the effect of supercalendering was found to vary corresponding to the clays used.
01 Jan 1976
TL;DR: In this article, the pigments of old wall-paintings in Istrian small chapels and churches originating from the eleventh to sixteenth century have been studied using X-ray diffraction as well as the light microscopy and chemical spot tests.
Abstract: The pigments of old wall-paintings in Istrian small chapels and churches originating from the eleventh to sixteenth century have been studied. The chemical composition and the choice of the pigments can give useful information in these studies. X-ray diffraction as well as the light microscopy and chemical spot tests have been used. Various pigments, white, red, brown, yellow, violet and green, from a few frescoes have been analysed and their chemical composition established.