- Introduction
Scrap steel is a general term for steel materials recycled after the use of steel products, substandard products generated during steel production, and processing waste materials used in steel applications. Scrap steel is a renewable green resource and an indispensable iron resource for the steel industry. The use of scrap steel in the steel industry avoids a series of high-carbon emission stages from ore mining, beneficiation, sintering, and ironmaking. Every ton of scrap steel used can reduce carbon dioxide emissions by 1.5-1.6 tons and energy consumption by 350 kg of standard coal equivalent. Due to the carbon-reducing properties of scrap steel, its utilization has significant strategic importance for the green development of China’s steel industry and the achievement of its “dual carbon” goals. - Current Status of Scrap Steel Utilization
The amount of scrap steel used is showing a year-on-year increasing trend. Currently, about 70% of scrap steel is used in converters, and about 30% is used in electric arc furnaces. The average scrap steel ratio for converters is about 16%, and for electric arc furnaces it is about 60%, indicating significant room for improvement. Due to insufficient scrap steel supply, high prices, and poor economic viability, electric arc furnaces are increasingly using a larger proportion of molten iron. - Carbon Emissions from Scrap Steel Used in Long and Short Process Steelmaking
To implement the “dual carbon goals,” efforts will be made to accelerate green and low-carbon development by actively cultivating green productivity, actively addressing climate change, and actively participating in global climate governance. The national carbon emission trading market will include the steel industry in 2025. This market will further drive enterprises’ low-carbon transformation, prompting steel companies to proactively reduce carbon emissions. Converter steelmaking and electric arc furnace steelmaking will inevitably compete for scrap steel resources with low-carbon properties.
- Rational Utilization of Scrap Steel and Leveraging its Carbon Reduction Advantages at Different Future Stages
The steel industry is undergoing significant changes, shifting from incremental growth to reduction, and entering a stage of quality improvement through reduction. Scrap steel resources are gradually increasing, while crude steel production will gradually decrease.
- Conclusion
As a recyclable ferrous resource, increasing the proportion of scrap steel can significantly reduce CO2 emissions and overall energy consumption, offering significant economic, environmental, and social benefits. Currently, there is a shortage of scrap steel resources. It is crucial to fully utilize the carbon-reducing properties of scrap steel and increase the overall scrap steel ratio in the steel industry. Compared to the short-process utilization of scrap steel in electric arc furnaces (EAFs), the CO2 emissions are lower when scrap steel is used in converters. Before 2035, considering both economic efficiency and the rational utilization of scrap steel to fully reduce carbon emissions, efforts should be made to increase the scrap steel ratio in converters and improve the utilization rate of EAFs. Therefore, the construction and production of EAFs should be rationally planned based on the amount of scrap steel resources available. Only when EAFs use green electricity will carbon emissions be low.
With the accumulation of iron in society, the amount of recycled scrap steel is increasing, and the steel ratio in EAFs is gradually increasing. It is predicted that by 2050, the steel ratio in EAFs will increase to about 65%, and CO2 emissions from the steel industry will decrease to about 500 million tons. At that time, with the adoption of green electricity in EAFs, CO2 emissions will be further reduced.