Traditionally, there are mainly two technical roads for modern steelmaking: one is the integrated technical road of traditional blast furnace plus alkaline oxygen converter (BF / BOR), which uses ore plus 20% waste to produce "native "VirginIron"; the second is the electric arc furnace (EAF) technology road, remelting waste, or using direct recovery pig iron, that is, blast furnace pig iron or direct recovery iron (DRI) to improve quality. But there is a third technological path in India, namely induction electric furnace (IF) steelmaking. In India, the dedication of induction furnaces is more outstanding. In the financial year 2010-2011, the output value of crude steel in induction furnaces accounted for 33% of the total output value of Indian crude steel.
The "meritorious" of the Indian steel industry
In the late 1970s, India used imported small induction electric furnaces to melt stainless steel waste to produce kitchen-grade materials. Gradually, the entrepreneurs found a way to produce soft steel ingots. Following the same principle, they successfully installed a 2 ton induction furnace to melt carbon steel waste. With the expansion of the method of producing ingots by using induction furnaces, the heavy rolling industry began to enter the induction melting mall in the mid-1980s, and the furnace capacity of induction furnaces also began to be added. Today, induction electric furnaces with a capacity of 12 to 15 tons are pervasive in India. Recently, induction electric furnaces with a capacity of 40 tons in India have recently been completed. Today around 1,100 companies across India operate induction furnaces of various specifications. The total steelmaking capacity of induction furnaces is estimated to reach 30 million tons / year in India, with a capacity utilization rate of approximately 75%.
The selection of induction furnace steelmaking technology has made scrap steel the primary feedstock for Indian steel mills. However, India has limited scrap resources that can be developed, which has led to a sharp increase in scrap quotations. In order to dispose of the lack of scrap, India will use direct recovered iron as the feedstock for induction electric furnaces, and the amount is constantly increasing. In 2010, India's direct recovery iron production value was 26.3 million tons, becoming the world's largest producer of direct recovery iron. About 3/4 of India's direct-recovery iron is produced in a rotary furnace using coal as a fuel, rather than in a traditional shaft furnace using natural gas as a fuel. Today, many direct-recovery iron plants in India consume 60% -80% of the charge of the direct-recovery iron. According to the professor, the innovation of the direct recovery category in India is to use direct recovery iron powder to make steel on a small-capacity induction electric furnace, which makes the Indian steel industry spread across the country.
The former Tata Steel's technical adviser thought, "When direct recovery iron is used only for electric arc furnaces in other parts of the world, India's direct recovery iron, especially the direct recovery iron powder has a particle size of less than 3 mm, and is not installed in the induction furnace through the mass mine In fact, India is the only country in the world that uses induction furnaces for large-scale steelmaking. In the 1980s, many small steel rolling mills in India closed electric arc furnaces and replaced them with induction furnaces with a capacity of 5 to 10 tons. Production costs are lower. "
The excellent performance of Indian induction electric furnaces has been valued by users in countries and regions such as the Gulf region, Saudi Arabia, Iraq, Iran, Turkey and Africa. Small steel mills in these regions and countries have introduced induction furnaces, billet casters, electric cranes and data processing equipment from India.