What is the molten iron pretreatment process? What is the purpose of this

      Hot metal pretreatment refers to the smelting process taken before molten iron enters the steelmaking furnace. The molten iron pretreatment process began with desulfurization outside the molten iron furnace. In 1877, A.E.Eaton used it to treat unqualified pig iron. The pre-desiliconization and pre-dephosphorization of molten iron began in 1897. The British Thiel and others used an open-hearth furnace to pretreat molten iron. After desiliconization and dephosphorization, steel was made in another open-hearth furnace, which was more efficient than two open-hearth furnaces at the same time. times increased. By the beginning of the 20th century, the development of molten iron pretreatment technology was once slow due to efforts to improve the steelmaking process. Until the 1960s, with the continuous improvement of the steelmaking process and the strict requirements on the quality of steel products by the material industry, the hot metal pretreatment developed rapidly and gradually became a necessary part of iron and steel metallurgy. In modern blast furnace ironmaking and converter steelmaking, molten iron pretreatment process is used to remove impurity elements in molten iron before entering converter smelting, so as to expand the source of iron and steel metallurgical raw materials, improve the quality of steel, and increase the variety of converter steelmaking. and improve technical and economic indicators. The molten iron pretreatment process is essentially to separate some tasks originally completed in the converter in space and time, and perform them in different reactors, so that the metallurgical reaction process can be carried out under more suitable ambient atmosphere conditions, so as to improve the efficiency of the process. Metallurgical reaction effect. At present, the molten iron pretreatment process has developed to a very mature stage, and the proportion of molten iron pretreatment in advanced countries is as high as 90-100%.

       For steelmaking, molten iron pretreatment is mainly to reduce the content of silicon, sulfur and phosphorus in molten iron to the required range, so as to simplify the steelmaking process and improve the quality of steel.