Properties of Clay Refractory Products

August 17, 2018
Clay-based refractory products are made of hard clay clinker as the main raw material, combined with clay (soft clay or semi-soft clay), semi-dry or plastically formed, and fired at 1300-1400 ° C.  The refractory material has an Al2O3 content of 30% to 48%. It is a versatile and most productive refractory product.
(1) Chemical and mineral composition: Al2O3 is 30% to 48%, SiO2 is 50% to 65%, and a small amount of alkali metal or alkaline earth metal oxide is used.
(2) Refractoriness: generally 1580 ~ 1750 ° C, increased with the increase of Al2O3 and SiO2.  When the low-melt impurities, especially the alkali metal oxides, are contained in a large amount, the refractoriness of the product is remarkably lowered.
(3) Load softening temperature: about 1250 ~ 1450 ° C, the range of variation is wide, the starting deformation temperature is lower, and the difference from 40% deformation temperature is 200 ~ 250 ° C
(4) The coefficient of thermal expansion is relatively low, and the average thermal expansion coefficient at 20 to 1000 ° C is 4.5 to 6 × 10 -6 / ° C. Its thermal conductivity is also low.
(5) The thermal shock stability is good and the fluctuation range is large. The 1100 ° C water cooling cycle is generally greater than 10 times.  This is related to the lower coefficient of thermal expansion of the clay refractory product, the inconspicuous conversion effect of the crystal form, and the plasticity at high temperatures.
(6) Chemical resistance: Because it is weakly acidic, it has strong resistance to acid slag erosion and is less resistant to alkaline material erosion.
For example: insulated fire clay bricks provided by our company
Insulated fire clay bricks manufactured by Jundao have been exported to all parts of the world. Products are widely used in electrolytic tanks, baking furnaces, glass furnaces, cement kiln, blast furnaces, hot blast stoves and other industrial thermal equipment. Taking high quality hard clay clinker as main raw material and combined with clay, fire clay bricks  made by Jundao have been exported to all over the world.