China
Africa
Explore chapters and articles related to this topic
Study of the effect on stability of slope variations and reserve estimation in the Kaolin mining quarry design
Published in Reginald E. Hammah, Thamer E. Yacoub, Alison McQuillan, John Curran, The Evolution of Geotech - 25 Years of Innovation, 2021
I.A. Chusna, N.R. Mulyaputra, V. Vergiagara, H. Suharyadi
Minerals that are available in abundance and a variety of different uses, and the characteristics that are determined based on the mineral structure and composition are a description of clay minerals (Grim, 1950). Clay minerals are a collection of naturally occurring very small crystalline particles that belong to argillaceous materials and have earthy properties (Grim, 1962). There are various mineral clays, such as kaolin, palygorskite-sepiolite or hormites, smectite, chlorite, illite, and clay layered. (Martin-Vivaldi and Robertson, 1971; and Murray, 2000). Kaolin is a white or nearly white hydrous aluminum silicate rock which is composed of clay material that has low iron content (Clarence and Paul, 1930). There are two types of kaolin in the nature, primary kaolin and secondary kaolin. Primary kaolin is formed due to the alteration of crystalline rocks, while secondary kaolin is formed due to the sedimentary processes of primary kaolin (Prasad et al., 1990). Kaolin in the District of Semin and its surroundings is kaolin that occurs due to hydrothermal alteration in dacitic igneous rocks and tuff breccias or this process is often referred to as kaolinization. This phenomenon is formed due to a solution of heat from the remaining magma that rises to the surface through cracks or gaps in dacite rocks so that it changes the mineral feldspar becomes kaolinite (Hidayah, 2005).
The socio-economic impact of small scale mining in Ghana
Published in Vladimír Strakoš, Vladimír Kebo, Radim Farana, Lubomír Smutný, Mine Planning and Equipment Selection 1997, 2020
S. Al-Hassan, R.S. Suglo, A. Cobblah
Kaolin (or China clay) is a soft, white, high-grade clay which is formed principally through hydrothermal alteration and by weathering in slightly acid ground solutions of igneous rocks which are rich in alumino-silicates such as feldspar, micas and zeolites. The best known kaolin deposits in Ghana are found in Abandze-Saltpond by-pass in the Central Region and at Kibi in the Eastern Region (Figure 1). However, in view of the fact that considerable areas of the country are covered by granitic rocks, there are the possibilities of the occurrences of other kaolin deposits with pegmatites and other granitic rocks in many parts of the country. One of the possible areas of interest is the western part of the country where decomposition of the granites through weathering is extensive and deep (Kesse 1985).
Prediction of reflectance spectrum for kaolin ores
Published in Heping Xie, Yuehan Wang, Yaodong Jiang, Computer Applications in the Mineral Industries, 2020
P.N. Conceicao, S. Sabedot, C.O. Petter
Kaolin is an important industrial mineral much used in a whole range of applications including paper industry, paints, ceramics, plastics, among others (Murray, 1980). The main parameters related to the quality of the kaolin are viscosity, particle size distribution and brightness. Brightness is its main characteristic. It is defined as the amount of light reflected by the sample with respect to the amount striking it at 457 nm on a given geometry of measurement. In most cases, the brightness of a mixture of kaolins cannot be obtained by simply averaging by weight the individual values of brightness of each sample. The solution for this problem is the use of the Kubelka-Munk (F(R)) function (Kubelka, 1948), which is largely employed in the paint industry for color matching purposes (Kortum, 1969).
Mineralogical and geochemical characterisation of kaolin deposit from Debre Tabor area northwestern, Ethiopia
Published in Applied Earth Science, 2021
Alemu Mesele, Teklay Gidey, Tilahun Weldemaryam, Wuletaw Mulualem, Tamrat Mekuria, Yahya Ali, Gizachew Mulugeta, Betelhem Tesfaye, Mulgeta Brihan
Kaolin is a white, soft, and plastic clay mineral (Akinyemi et al. 2014). Based on its genesis, kaolin is classified as a primary and secondary deposit. The primary deposit formed in situ from hydrothermal alteration of granitic rocks (Murray 1988). While secondary kaolin deposit is the weathering products of pre-existing rocks, and subsequent alteration of alumino-silicates into residual and sedimentary clays (Murray 1988). The chemical weathering resulted in kaolinitic clay due to high rainfall, warm temperature, lush vegetation, low relief, and high groundwater table (Cravero and Dominguez 1999; Lopez-Galindo and Viseras 2007; Nwoye 2010). Therefore, kaolin is formed due to weathering followed by transportation of stream water to a quite freshwater environment. Further oxidation and digenesis can modify the original clay mineralogy with kaolin quality improvement (Hassan et al. 2012). According to Rashad (2013), kaolin is primarily composed of aluminium, silicon, ferrous and ferric iron, and hydroxyl groups with different impurities such as quartz, feldspar, tourmaline, and zircon.
Latest trends for structural steel protection by using intumescent fire protective coatings: a review
Published in Surface Engineering, 2020
Muhammad Yasir, Faiz Ahmad, Puteri Sri Melor Megat Yusoff, Sami Ullah, Maude Jimenez
Kaolin is a fine clay mineral with chemical composition of Al2O3•2SiO2•2H2O. The crystal structure consists of two layers, i.e. tetrahedral silica (SiO2) sheet that is connected through oxygen to alumina (AlO6) that has an octahedral sheet. Clay minerals contain kaolinite, nacrite, dickite, halloysite, montmorillonite, illite, chlorite, sepiolite and saponite [166,167]. The chemical structure of all kaolin clays is almost similar. The only difference is the stacking assembly of layers on each other. Kaolinite is the mineral form of kaolin. The chemical formula used in the study of minerals is Al2Si2O5(OH)4 (theoretically 39.8% alumina + 46.3% silica + 13.9%) but the elements are not diverted from this ideal composition.
An underwater lighting and turbidity image repository for analysing the performance of image-based non-destructive techniques
Published in Structure and Infrastructure Engineering, 2018
Michael O’Byrne, Franck Schoefs, Vikram Pakrashi, Bidisha Ghosh
Both phases of the experiment followed the same process in terms of controlling turbidity and illuminance levels. A flowchart of the test process is shown in Figure 9. The turbidity was measured using a digital turbidimeter (model: Hach 2100P), which operates by measuring the loss of intensity of transmitted light through a water sample. Initially, the basin was filled with clear water. After all the photographs were captured at this turbidity level for each illuminance level, finely sieved kaolin was added in order to bring the turbidity up to 6 NTU, and later, to 12 NTU. Kaolin is a soft white clay consisting principally of the mineral kaolinite which goes into suspension when mixed with water. Regular stirring was carried out to ensure kaolin remained in suspension and was uniformly distributed.