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Stability is the Soul of Blast Furnace Iron Smelting
The blast furnace iron smelting process is a steel smelting process carried out in the oxygen converter of the blast furnace, raw ore is the main raw material for steel smelting, a part of fuel, limestone flux, and some return materials are added within a certain range in the blast furnace. As the main type of iron smelting process, blast furnace iron smelting is the most widely used among the steel smelting processes at present, accounting for more than 95% of the total steel output.
The stability of blast furnace iron smelting process is the soul of the entire iron smelting process. The stability here mainly refers to the stable production of large-scale blast furnaces, but does not refer to small-scale blast furnaces for laboratory research and development. Since the 17th century, a large number of large tracts of land resources were constructed in Europe and the rate of steel smelting has been growing rapidly, increasing by 10 times of the total equivalent to 1.6 pound per capita by 1700. The rapid growth of steel smelting technology is mainly due to the improved production process and increased production stability.
Blast furnace operating stability principle is narrow range control. The stability of blast furnace iron smelting process is mainly affected by five aspects. First, the quality of raw ore should be as uniform as possible, so that the proportion and chemical composition of the raw materials in the furnace should be as similar as possible. Secondly, the addition speed and quantity of material and fuel should be uniform and rational. Third, the degree of burden densification should be uniform, and the burden distribution should be uniform. Fourthly, the uniformity of thermal energy supply, oxygen supply and blowing pressure should be ensured. Last, the design, equipment and operating conditions of the furnace should be reasonably considered, and the operating conditions should be controlled within a certain temperature and pressure range.
At present, the design of a large number of blast furnaces is mainly carried out from the perspective of ignition and thermal energy supply. As a powerful iron production device, blast furnace starts mainly from three aspects. First, the air blowing rate, air pressure and air temperature should take into account the fluctuation of air pressure, air temperature and air volume. The second is the speed and sequence of material addition to ensure the smooth ignition of the blast furnace. The third is coal injection, whose duration and method have a great influence on the stability of the blast furnace.
From the perspective of technology, the stability of blast furnace iron smelting process can be improved in four aspects. First, the quality of raw materials should be improved, and materials with similar properties should be selected as much as possible to ensure constant smelting results. Secondly, new technology should be adopted to increase oxygen enrichment in the furnace. Thirdly, the wall lining of the blast furnace should be strengthened, so as to improve the service life of the blast furnace lining. Fourthly, new technology should be adopted to optimize the process of steel smelting, so as to reduce the impact of furnace working condition on the blast furnace stability.
In summary, stability is the soul of blast furnace iron smelting, it can not only directly affect the quality and output of iron ore smelting, but also promote the comprehensive mechanization of iron smelting, which is an indispensable part of steel production in modern iron and steel industry. As for the stability of iron smelting process, it is necessary to take into account the design, production, operation and other aspects, and it is necessary to rationally use raw materials and carefully designed according to the process requirements in order to make the stability of iron smelting process more perfect and the quality and output of iron smelting more stable.
