The chemical composition of refractories, that is, the chemical composition of refractories, is one of the most basic characteristics of refractory products. Refractory materials are heterogeneous and have main and secondary components. The basic component is usually referred to as the principal component, and the other components are referred to as the secondary components. By-ingredients are added ingredients that are intentionally added to improve the performance of certain aspects of the product, or unintentionally or involuntarily brought into the unhelpful or harmful ingredients, which are respectively added ingredients and impurities.

The main component of refractory materials is usually one or several kinds of high-melting refractory oxides or composite minerals or non-oxides, which is the main body of refractory products and directly determines the basic conditions for the performance of refractory products.

The added ingredients of refractory materials are often used to make up for the shortcomings of the main component in the use performance or production performance and operational performance, often known as binders, mineralizing agents, stabilizers, sintering agents, water reducing agents, anti-hydration agents, antioxidants, coagulants, expansion agents, etc., a wide variety of added ingredients, is the focus of the current refractory industry research object. Their common characteristics are: the amount of accession is small; Can obviously change the function or characteristics of refractory products; It has no serious influence on the main properties of the product.

The impurity composition of refractory materials refers to the part that is brought into or mixed into the production process due to the limited purity of raw materials and has an adverse effect on the performance of refractory products. In general, K2O, Na2O and FeO or Fe2O3 are harmful impurities in refractory materials. In addition, acidic oxides (RO2) in alkaline refractories (RO as the main component) and alkaline oxides in acidic refractories are considered harmful substances, which have a strong solvent effect at high temperatures. This effect reduces the formation temperature of the eutectic liquid phase, increases the amount of liquid phase generated, and accelerates the growth rate of the liquid phase volume with the increase of temperature, which seriously affects the high temperature performance of refractory products.

Through the data of chemical composition analysis, according to the type and quantity of the ingredients contained in it, the purity of the product or raw material can be judged and the chemical characteristics of the product.