Listing description
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.
Detailed description
They are
fine-grained and plastic in nature, and, unlike most earthenware clays, produce a
fine quality white-coloured pottery body when fired,
which is the key to their popularity with potters.
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[2] in Devon and Dorset in South West England.[3] They are commonly
used in the construction of many ceramic articles, where their primary role,
apart from their white colour, 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".
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. 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.
PRICE
$2.86/KG OR $1.30/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
website: www.franchiseminerals.com
No comments:
Post a Comment