Direct steelmaking process using iron ore in converter system

Abstract

The invention belongs to the field of metallurgical smelting, and particularly relates to a direct steelmaking process using iron ore in a converter system. The process is characterized by comprising the following steps: (1) increasing the bottom blowing flow by 30-50% in the early stage of converter blowing, lowering the position of an oxygen lance by 200-500mm, and increasing the oxygen flow by 10-20%; and (2) adding mechanically pressed balls into the converter, wherein 50% of the mechanically pressed balls are added before the converter blowing and another 50% are added in batches in the blowing process, and all are added 3 minutes before the endpoint. The content of iron oxide in the slag can be quickly adjusted. Slagging in the early stage of converter smelting is effectively promoted so as to promote the early dephosphorization reaction, the phosphorus content in the steel is reduced, and the dephosphorization rate is improved. The process facilitates early and thorough slagging, is an effective means for adjusting the slag activity in the blowing process and can effectively improve the dephosphorization rate and desulfurization rate of the converter to maintain the lining.

Description

technical field [0001] The invention relates to a process for preparing mechanical pressure balls of carbon-containing iron materials for direct steelmaking in a converter, belonging to the field of metallurgy. Background technique [0002] During the blowing process of converter steelmaking, the carbon element in molten iron reacts with high-pressure pure oxygen, burns to generate heat, heats scrap steel and other coolants and fluxes, and finally reaches the temperature and composition requirements of molten steel, and the blowing is over. [0003] When the production capacity of molten iron is less than the production capacity of the converter, in order to increase the production capacity of steelmaking, two methods are generally adopted, one is to increase the proportion of scrap steel in the metal material, and the other is to increase the amount of iron-containing ore materials. However, the ratio of molten iron to scrap must comply with the heat balance of the converte...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the contradiction of heat balance, the former Soviet Povetsk Iron and Steel Company, domestic Baosteel, Jiugang, Panzhihua Iron and Steel and other enterprises have used solid carbon-containing materials such as coal, silicon carbide, coke, electrodes, natural graphite, and carbon black in the converter. It is a test to increase the ratio of smelting scrap steel, but it cannot be popularized due to low utilization rate, difficulty in being absorbed by molten iron, difficult operation control, etc., and no industrial application