Clay refractory bricks are a type of refractory bricks, belonging to shaped refractory products, which are a series of refractory materials distinguished from the delivery form. Now the definition of refractory bricks has not only depended on whether the refractoriness is above 1580 °C. At present, refractory materials generally refer to inorganic non-metallic materials used in the lining of production equipment such as metallurgy, petrochemical, cement, ceramics, etc. The acid refractory material is mainly composed of silicon oxide (SiO2), and silicon bricks and clay bricks are commonly used. The clay brick is made of refractory clay or coke gypsum clinker. It contains 30%-46% alumina and has a refractoriness of 1580-1770 °C. It is a weakly acidic refractory material with good thermal shock resistance and corrosion resistance to acid slag. It is widely used. The clay brick is made of refractory clay as the main raw material. It is called ordinary clay brick. It is made of coke clinker as the main raw material. The clay brick with the porosity of 17% or less is called low-porosity clay brick. The two kinds of clay bricks are divided into several grades according to the physical and chemical indicators among them, and the price difference between ordinary clay bricks and low-porosity clay bricks is large. Neutral refractories are mainly composed of alumina, chrome oxide, silicon carbide or carbon.