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Classification of Clay
- Aug 21, 2018 -

1. Refractory clay

This is a siliceous clay rich in hydrated aluminum silicate. It has the ability of non-deformation, non-fragmentation, non-softening and non-paste at high temperature. Low iron, calcium and alkali metals are close to kaolin in composition, and the better grade after calcining contains at least 35%Al2O3 (dictionary of mining terms, compiled by the geological society of America).

2. Flint clay

A smooth, flint-like refractory clay rock, consisting mainly of kaolinite, with a seash-like section of cleavage, resistant to ripening in water. Milling in water for long periods of time produces plasticity (dictionary of mining terms, geological society of America).

3.Fire-resistant soil.

It is a part of a mixture used in the production of refractory bricks. It consists of calcined clay or reground bricks, also known as clinkers.


This is mainly made up of (hard) hydrometeorite. The bauxite > mechanipore consists of refractory clays bonded to the material. The purest hydralite clay often contains 70-80% Al2O3 after calcining.

5.Intensive Chinese clay

Soft clay, refractory clay and kaolin: <45% Al2O3

Flint clay, kaolin and high alumina ore: >45%Al2O3

High alumina clay clinker (also known as "ripe bauxite") : 75-90%Al2O3

All components of raw refractory clay ground to appropriate fineness, as with calcined refractory clay or crushed refractory clay bricks, or both