An obsolete, local term for a fibrous talc from New York State, USA; or for pyrophyllite from China (also obsolete).

An obsolete term for pyrophyllite or a mixture with dominant pyrophyllite.

Ageing refers to:

a) a process where the physical properties, for example the rheology, of wet clay are improved by allowing the clay to sit undisturbed for a period, sometimes for years but more often for days or months, to allow the water to become more homogeneously distributed or to promote the growth of microorganisms. An improvement in plasticity by ageing is important for pressing and drawing of the clay for commercial production of ceramics.
Syn., aging, maturation;

b) in soil mechanics, aging is also referred to the process of secondary consolidation or drained creep.
Cf., drained creep, secondary compression

See flocculation.

See flocculation.

See ageing.

A process of separating, fractionating, or manipulating fine particulate materials (or lighter particles) by gravitation in a vertically directed, usually upwards, moving air stream. This method is typically used for particles with sizes greater than 1ìm. The smaller or lighter particles rise to the top (overflow) above the coarser heavier fractions (underflow) because their terminal velocities are lower than the initial velocity of the rising fluid. The terminal velocities of various particle sizes in any media is calculated by Stokes’ law.
See also Stokes’ law;
Syn., elutriation

A process where kaolin is dried, transported on a column of rapidly moving air through a pulverization mill, and passed through a cyclonic air-classifier where coarse, sand-size particles are removed as gangue or returned to the mill for further size reduction. The term is used in the kaolin industry and refers to the less costly, dry-processed and air-classified powder products where bulk chemistry is of concern, but where purity, handling, and appearance may be less important.
Cf., air classification

See feldspar, alkali feldspars.

A regularly ordered interstratification of a talc-like layer and trioctahedral smectite-like layer in a ratio of 1:1 (Veniale and van der Marel, 1969; Bailey, 1981).
Cf., interstratification