In the process of iron and steel smelting, if the carbon content in the molten iron is not improved well, it will affect the quality of the steel and increase the cost of smelting and casting. In order to ensure the quality of steel casting, the quality of smelting can be improved by increasing the amount of smelted pig iron, but the raw iron of pig iron is relatively high. When using a recarburizer, it is not necessary to put too much pig iron. It is possible to increase the carbon content in the molten iron.
At present, there are many materials for cast iron recarburizers on the market. In general, coal quality recarburizers, petroleum coke recarburizers, calcined petroleum cokes, graphitized petroleum coke recarburizers and artificial graphite can be used as cast iron smelting. Recarburizer used. Although these products can be used as recarburizers, you must choose the right recarburizer when you buy them. If the quality of the products to be cast is high, you need to choose artificial graphitized petroleum coke recarburizer.
If the quality of the smelting metal is not high, you can choose a lower cost recarburizer. For example, in converter smelting, when high carbon steel is used, you can use petroleum coke with a lot of impurities as a recarburizer. However, the requirements for the recarburizer for the top-blown converter steelmaking are higher than the carbon of the fixed furnace recarburizer. The ash, volatiles, sulfur, phosphorus, nitrogen and other impurities are also required to be high in content, and are required to be dry, clean, and granular. Moderately, it is necessary to choose a calcined coke recarburizer and a graphitized recarburizer.
Among them, the most used mainstream carbonizers specifications are: fixed carbon C ≥ 98%, volatile matter ≤ 1.0%, sulfur content ≤ 1%, moisture ≤ 0.5%, particle size is more than 1-5mm, this recarburizer The indicator shows the calcined petroleum coke recarburizer, which is calcined petroleum coke. In the past, in the domestic smelting industry, relatively low-end non-graphitizing recarburizers were generally used. With the improvement of product quality and upgrading, more and more enterprises using graphitized petroleum coke in China will increase carbonization of graphitized petroleum coke. The indicators of the agent are: fixed carbon C ≥ 98.5%, volatile matter ≤ 0.5%, sulfur content ≤ 0.1%, moisture ≤ 0.5%, particle size between 0-5mm.
Different types of recarburizers are used differently. In the process of selecting a recarburizing agent for steel making, the particle size should be moderate, the particle size is too fine to be easily burned, and when it is too coarse to be added, it floats on the surface of the molten steel and is not easily absorbed by the molten steel. With the development of the market, the quality requirements of steelmaking refining agents are getting higher and higher, especially the conversion from coal quality carbonizers to calcined petroleum coke recarburizers, or graphitized petroleum coke recarburizers. .