Ball clay

Ball clay

Ball clays are kaolinitic sedimentary clays, that commonly consist of 20-80% kaolinite, 10-25% mica, 6-65% quartz. Localized seams in the same deposit have variations in composition, including the quantity of the major minerals, accessory minerals and carbonaceous materials such as lignite. They are fine-grained and plastic in nature.

Ball clays are relatively scarce deposits due to the combination of geological factors needed for their formation and preservation. They are mined in parts of the Eastern United States and from three sites [The Bovey Basin in South Devon, the Petrockstowe Basin in North Devon and the Wareham Basin in South Dorset.] in Devon and Dorset in South West England.cite web
last = Highley
first = David
authorlink =
coauthors = Bloodworth, Andrew; Bate, Richard
title = Ball Clay - Mineral Planning Factsheet
work =
publisher = British Geological Survey
date = 2006
url = http://www.mineralsuk.com/britmin/mpfball_clay.pdf
format = pdf file
accessdate = 2008-08-05] They are commonly used in the construction of many ceramic articles, where their primary role is to either to impart plasticity or to aid rheological stability during the shaping processes.

History

The name "ball clay" is believed to derive from the time when the clay was mined by hand. It was cut into 15 to 17-kilogram cubes and during transport the corners of the cubes became rounded off leaving "balls".cite web
title = What is ball clay?
publisher = Industrial Minerals Association - North America
url = http://www.ima-na.org/about_industrial_minerals/ball_clay.asp
accessdate = 2008-08-05]

The ceramic use of ball clays in Britain dates back to at least the Roman era. More recent trade began when a clay was needed to construct tobacco pipes in the 16th and 17th century.cite web
title = The Widespread Use of Ball Clay
work = Introduction to Ball Clays
publisher = The Ball Clay Heritage Society
url = http://www.clayheritage.org/pages/wideuses.htm
accessdate = 2008-08-05] In 1771 Josiah Wedgwood signed a contract for 1400 tons a year of ball clay with Thomas Hyde of Purbeck enabling him to fire thinner walled ceramics.cite web
title = History of Ball Clay - Swanage Railway
publisher = The Purbeck Mineral & Mining Museum
url = http://www.pmmmg.org/History.htm
accessdate = 2008-08-05]

ee also

Ball clay and the Stover Canal

Notes and references


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Look at other dictionaries:

  • Ball Clay — Le ball clay est une roche contenant généralement trois minéraux dominants : 20 à 80 % de kaolinite ; 10 à 25 % de mica et 6 à 65 % de quartz. Le ball clay fait partie des argiles secondaires ou alluviales. Comparé au… …   Wikipédia en Français

  • Ball clay — Le ball clay est une roche contenant généralement trois minéraux dominants : 20 à 80 % de kaolinite ; 10 à 25 % de mica et 6 à 65 % de quartz. Le ball clay fait partie des argiles secondaires ou alluviales. Comparé au… …   Wikipédia en Français

  • ball clay — noun Etymology: from its formation into balls for transport from the mines : a very plastic high firing clay that fires white to light buff and is used especially to give plasticity to clayware bodies containing short clays * * * Ceram. a fine… …   Useful english dictionary

  • ball clay —    In ceramics, an ingredient included in a many clay bodies because of its plasticity. Ball clay may be black or gray in color but fires almost white. It contracts considerably as it dries and when fired …   Glossary of Art Terms

  • ball clay — Ceram. a fine dark kaolinic clay that turns white or nearly white when fired, used in the manufacture of a wide variety of ceramic wares in combination with other clays for its exceptional bonding properties and plasticity. [1805 15] * * * …   Universalium

  • ball clay — noun A type of clay …   Wiktionary

  • ball clay — fine highly plastic clay that turns nearly white after firing (used to manufacture fine ceramics) …   English contemporary dictionary

  • ball clay — noun a fine textured clay used in the manufacture of ceramics …   English new terms dictionary

  • Purbeck Ball Clay — Mine …   Deutsch Wikipedia

  • Purbeck Ball Clay — is a concentration of ball clay found on the Isle of Purbeck in the English county of Dorset.GeologyThe main concentration of ball clay in Dorset is to the north of the Purbeck Hills centred around Norden. Ball clays are sedimentary in origin.… …   Wikipedia

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