Converter

The SMG GROUP’s technical team is highly proficient in steelmaking processes and has extensive experience in complete converter steelmaking projects. Based on customers’ diverse needs, SMG GROUP can provide mature, customized steelmaking solutions to meet their requirements.

Converter steelmaking uses molten iron, scrap steel, and ferroalloys as its primary raw materials. It relies on the physical heat of the molten iron itself and the chemical reactions among its components to generate heat, thereby completing the steelmaking process within the converter.

Converters are classified according to refractory lining into acidic and basic types; based on the location where gas is blown into the furnace, they include top-blown, bottom-blown, and side-blown designs. According to the type of gas used, they are further divided into air converters and oxygen converters. Basic oxygen top-blown and combined top-and-bottom blown converters are widely employed due to their fast production rates, high output, large single-furnace capacity, low costs, and minimal investment. These converters are primarily used for producing carbon steel, alloy steel, as well as smelting copper and nickel.

Typically, the oxygen top-blown converter is the most common type of steelmaking equipment in use. The entire process unfolds as follows:

First, scrap steel and other materials are loaded into the furnace, followed by the addition of molten iron and an appropriate amount of slag-forming agents (such as quicklime). After charging, an oxygen lance is inserted from the top of the furnace to inject oxygen—high-pressure oxygen with a purity exceeding 99%—enabling direct oxidation reactions with the high-temperature molten iron to remove impurities. Replacing air with pure oxygen helps avoid the brittleness caused by nitrogen in the air, as well as the drawback of heat loss associated with nitrogen removal. Once most of the sulfur and phosphorus have been eliminated and the steel’s composition and temperature meet the required specifications, the blowing process is halted, the lance is raised, and preparations are made for tapping. During tapping, the furnace is tilted, allowing the molten steel to flow through the tap hole into a ladle, while deoxidizers are added to reduce oxygen content and adjust the chemical composition. Once the steel meets quality standards, it can be cast into ingots or billets; these ingots can subsequently be rolled into various steel products.