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There are a wide variety of refractory raw materials, and there are also numerous classification methods. Based on the method of their production, raw materials can be divided into two main categories: natural raw materials and synthetically produced raw materials. Natural mineral raw materials still constitute the majority of refractory raw materials. The various minerals found in nature are composed of the different elements that make up these minerals. It has been determined that the total amounts of oxygen, silicon, and aluminum account for approximately 90% of the total elements in the Earth’s crust. Oxides, silicates, and aluminosilicates are predominant, making them natural refractory materials with extremely large reserves. The main types of natural refractory raw materials include: silica, quartz, diatomite, waxstone, clay-based refractory materials, bauxite, spinel-group minerals, magnesite, dolomite, limestone, forsterite, serpentine, talc, chlorite, zircon, zirconium orthosilicate, perlite, chromite, and natural graphite. Natural raw materials usually contain many impurities, have unstable compositions, and exhibit significant variations in properties. Only a few of these materials can be used directly; most require purification, grading, or even calcination before they can meet the requirements for producing refractory materials. The types of natural mineral materials that can be used as refractory raw materials are limited; they are not capable of meeting the requirements for high-quality, high-tech refractory materials needed in modern industry. Synthetic refractory raw materials have seen rapid development over the past few decades. These synthetic materials allow for the achievement of precisely defined chemical compositions and structural arrangements, and they offer consistent quality, making them the primary raw materials for modern high-performance and high-tech refractory materials. The main methods for synthesizing refractory raw materials are sintering and electrofusion. Commonly used synthetic refractory materials include: mullite, magnesia-alumina spinel, zirconium mullite, cordierite, aluminum titanate, silicon carbide, etc. As the application of micro-powder technology in the field of refractory materials continues to expand, more and more methods for synthesizing such micro-powders have been developed, including chemical coprecipitation, sol-gel method, spray thermal decomposition, and vapor phase methods. Based on the chemical composition of the refractory raw materials, they can be divided into oxide raw materials and non-oxide raw materials. With the development of modern science and technology, certain organic compounds have become precursors or auxiliary materials for high-performance refractory materials. Based on their chemical properties, refractory materials can be divided into acidic refractory materials, such as silica and zirconia; neutral refractory materials, such as corundum, bauxite (slightly acidic), mullite (slightly acidic), chromite (slightly basic), and graphite; and alkaline refractory materials, such as magnesia sand, dolomite sand, and magnesio-calcareous sand. Based on their role in the refractory material production process, refractory raw materials can be divided into primary raw materials and auxiliary raw materials. The main raw materials constitute the core of refractory materials. Auxiliary materials are further divided into binders and additives. The function of the binder is to ensure that the refractory material body possesses sufficient strength during production and use. Commonly used materials include sulfite pulp waste liquid, asphalt, phenolic resin, aluminate cement, water glass, phosphoric acid and phosphates, sulfates, etc. Some of these raw materials themselves serve as binders, such as those used to bind clay. Additives are used to improve the production or construction processes of refractory materials, or to enhance certain properties of these materials, such as stabilizers, accelerators, water reducers, inhibitors, plasticizers, foaming agents, dispersants, expanders, antioxidants, etc. Table 1 Comprehensive Classification of Refractory Raw Materials http://www.znhcl.com/uedits/da6604d4ac2e4136a17cf8961446bde6.jpg_water.jpg *Conventionally, refractory raw materials are generally classified comprehensively based on their chemical and mineral composition, methods of extraction or processing, properties, and roles in refractory materials. Table 1 is a comprehensive classification table of refractory raw materials. Table 2 shows the types of refractory materials and the refractory raw materials used. Table 2 Types of refractory materials and the refractory raw materials used http://www.znhcl.com/uedits/368fe589ec44427e9e748033b7ab2581.jpg_water.jpg