There are many kinds of additives, and the production process is different. There are wood carbon, coal carbon, coke, graphite and so on. There are many kinds of different kinds. A high - grade carbon - carburizer generally refers to a graphitized carbon - based additive, which in high temperature is graphite in the microform of graphite. The graphite can reduce the content of impurities in the carburizing agent, increase the carbon content of the carbon and reduce the sulfur content. The use of carburizer in casting can greatly increase the amount of scrap steel, reduce the amount of pig iron, or use no pig iron. The feeding method of furnace smelting should be put into the furnace with waste steel and other materials, and the small dosage can be added to the surface of the molten iron. However, it is important to avoid large quantities of iron and water in order to prevent excessive oxidative effects and insufficient carbon content of casting. The amount of carbon added is determined according to the ratio of other raw materials and carbon content. Different types of cast iron are selected according to the need to choose different types of carbon. The characteristics of the carburizing agent itself choose pure carbon graphitized material, reduce the impurities in pig iron, and the choice of carbon addition agent can reduce the production cost of the casting.