The resistance temperature of this soil is 1500°C. These soils consists of 18% to 30% of Aluminum oxide, 50% to 60% of Silica and 10% to 12% of volatile material (mostly water) which is realesed from the material during the heat.
an important feature of of many refractory soils is the ability to absorb water and form a doughy mass that can be molded into an arbitrary shape. The variety of compounds in this soil has increased its usage in various industries such as tiles, ceramics,glazes and primary industries such as metallurgy and steel mill. The application of this soil is in the preparation of refractory bricks , used in furnace repairs, glass, ceramics and type of furnaces.
The materials used in the construction of refractories can be divided into Oxide and non-Oxide categories. Oxide refractories are the most common type of refractories used in industry. Oxide refractories mostly contain oxides such as Aluminum oxide (alumina), Silicon oxide (silica) and Magnesium oxide (magnesite ). Other compounds such as chromite, zircon and zircona are used in some refractory products to increase abrasion resistance.
Refractory soils are mostly composed of halosite, kaolinite,monothermite, hydrocele and quartz, feldspar impurities. Due to the variety of refractory soils, we should consider some points when selecting and purchasing refractory soils needed for manufacturing the products. If the impurities of refractory soils are from bauxite minerals, this will increase the the amount of alumina and thus increases the igneousness of the soil. If the impurities are from materials such as iron and titanium compounds, this will decrease the dough point of the part made from that given refractory soil.
Foundry industry 
