china clay

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Related to china clay: fire clay, kaolin, Ball clay, Kaolin clay

china clay,

one of the purest of the clays, composed chiefly of the mineral kaolinitekaolinite
, clay mineral crystallizing in the monoclinic system and forming the chief constituent of china clay and kaolin. It is a hydrous aluminum silicate commonly formed by the weathering and decomposition of rocks containing aluminum silicate compounds; feldspar is a chief
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 usually formed when granite is changed by hydrothermal metamorphismmetamorphism,
in geology, process of change in the structure, texture, or composition of rocks caused by agents of heat, deforming pressure, shearing stress, hot, chemically active fluids, or a combination of these, acting while the rock being changed remains essentially in the
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. Usage of the terms china clay and kaolin is not well defined; sometimes they are used synonymously for a group of similar clays, and sometimes kaolin refers to those obtained in the United States and china clay to those that are imported. Some authorities term as china clays the more plastic of the kaolins. China clays have long been used in the ceramic industry, especially in fine porcelains, because they can be easily molded, have a fine texture, and are white when fired. France's clays are made into the famous Sèvres (see A. BrongniartBrongniart, Alexandre
, 1770–1847, French geologist, mineralogist, and chemist. As director of the Sèvres porcelain factory from 1800, he was responsible for its international fame.
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) and Limoges potteries. These clays are also used as a filler in making paper. In the United States, deposits are found primarily in Georgia, North Carolina, and Pennsylvania; china clay is also mined in England (Cornwall) and France.

china clay

[′chī·nə ‚klā]
A high-grade white kaolin composed principally of the mineral kaolinite, and often occurring as a lenticular-shaped body; used in the manufacture of ceramics, paper, rubber, catalysts, and ink.
References in periodicals archive ?
There are two other smaller UK producers of china clay in Cornwall which between them produce around 340,000 tonnes a year.
Tenders are invited for Wash Hand Basin China Clay For Ac Coaches, Flat Back Size- 450X300mm , Material Specification : Porcelain, Is:2556 Part-4 : 2004.
Prequalification are invited for Carry out EIA studies of our "Kannapuram China Clay Mining Project.
They were built to shunt the products of Cornish china clay pits to the docks for onward shipment by sea, their height being exactly the same as the china clay wagons they moved.
Tob's Black (Cone 03 - 6) China Clay 57 Silica 23 Frit 4110 20 Add 200 grams of copper oxide to one litre of glaze mix.
Capt James Nolan's schooner the Loch Ryan, which was carrying china clay from England to Arklow, was bombed and machine-gunned by the Luftwaffe off Cornwall on August 16, 1940.
China clay has been mined in Cornwall for 260 years.
Come away with us on September 20 when we set off on a three day trip to appreciate The Eden Project - the size, the scale, the vision needed to turn a derelict, water-logged china clay pit into one of the world's most significant environmental projects.
The claim arises from a 16 August 1940 attack by three German warplanes on the 240 ton schooner "Loch Ryan" as it made its way from England to Arklow, Co Wicklow, with a cargo of china clay.
English China Clay International (ECC) in Atlanta, Georgia expanded its agreement with Ross.
The landscape of Cornwall is made mysterious and sometimes magical by the local china clay industry, which leaves great white tips and pits as the kaolin is extracted from the rotten granite that underlies much of the rough brown moorland surface.

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