The plasticity of refractory clay and the industrial use of ore are four characteristics of soft clay, semi-soft clay, hard clay and high alumina clay. Generally simple soft clay, water-dispersible, can be formed after being plastically mixed with liquid clay; scattered and poor semi-soft clay dipped in bulk can also be formed after being plastically mixed with liquid clay. These two clays are often used as binders in the production of refractory products. Clay usually has a hard block or flat shape, generally does not stick to water, has high refractoriness, and is the main raw material for refractory products. The Al2O3 content of high alumina clay has high hardness, high refractoriness, and high proportion of clay used to make products.

Refractory clay is mainly used in metallurgical industry, refractory material production model (various bricks) unshaped refractory material, the amount is about 70% of all refractory materials. Hard clay refractory clay refractories are used to produce blast furnaces, blast furnaces, hot blast stoves, ladle lining bricks, and brick plugs. High-alumina clay is used to produce electric furnaces, high-alumina bricks for blast furnaces, high-alumina bricks, and high-alumina refractory cement lining. High-hard clay aluminum clay is often used as calcined mature material (1400~1800℃).