Future Development of Electric Arc Furnace Steelmaking Technology in China

Future Development of Electric Arc Furnace Steelmaking Technology in China

By Ni Bing

In recent years, the global crude steel annual output has ranged between 1.6 billion and 1.8 billion tons, of which electric furnace steel accounts for over 400 million tons, approximately 25%. Outside China, the share of electric furnace steel in the global steel industry has exceeded 40%. The United States has the highest proportion among developed countries, reaching 67%. In 2020, China produced 1.065 billion tons of crude steel, of which electric furnace crude steel accounted for approximately 96 million tons, or about 9%, indicating significant room for growth. By the end of 2020, China had around 420 electric furnaces of 30 tons or above, with a total capacity of 182.25 million tons.

Compared with the long process (integrated steelmaking), the short-process electric furnace emits only 25% of CO2, generates 1/30 of solid waste, and consumes roughly 50% of energy, showing clear advantages. The short process also offers benefits such as immediate start-stop operation, high production flexibility, and the ability to utilize urban waste. With the gradual release of scrap steel resources in China, electric furnaces have enormous development potential over the next 10–15 years. The government encourages steelmaking from scrap and the short process, supports capacity replacement without adding new production, and promotes relocating high-environmental-pressure or overcapacity production to areas rich in scrap steel and lacking steel supply.

As global steel output increases, electric furnace steel production is rising annually. Outside China, electric furnace steel already accounts for over 40% of global steel production, while China still has substantial growth potential. Future electric furnaces should focus on models that meet requirements such as high efficiency, energy saving, continuous charging, scrap preheating, environmental protection, and waste heat recovery. Furnace selection should align with metallurgical process requirements for sustainable development. Development should also emphasize energy-efficient and low-cost production, green key technologies, intelligent manufacturing, and high-value specialty steel metallurgy.

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Electric Arc Furnace Steelmaking Technology

Focusing on goals of high efficiency, simple functionality, environmental friendliness, intelligent control, and diverse raw materials, electric arc furnace (EAF) technology continues to advance. High-efficiency steelmaking aims to minimize refining cycle and arc-on time while reducing power consumption. Work should focus on six aspects:

1. Increasing input power per ton of steel through larger and higher-power equipment.

2. Enhancing chemical heat from element oxidation in steel and from oxygen lances.

3. Utilizing sensible heat from preheated scrap.

4. Improving electrical efficiency and power factor through optimized power supply, smart EAFs, and short-mesh structures.

5. Reducing downtime, including charging, electrode connection, tapping, and furnace maintenance times.

6. Producing single-grade steel in production lines, which is more efficient than multi-grade production.

Advanced furnace types enable full scrap preheating, continuous charging, lidless operation, flat molten pools, low noise, minimal dust, trace dioxins, and dust recovery. EAF technology has evolved from conventional open-lid furnaces to Fuchs (vertical preheating), Consteel (horizontal continuous charging), Quantum, Ecoarc, Sharc, CISDI-Green, and CERI-s1-Arc furnaces.

Conventional open-lid furnaces are reliable but inefficient in achieving the above goals. In the 1990s, Fuchs and Consteel furnaces were introduced to China. Fuchs furnaces were largely phased out due to high failure rates and cost issues. Consteel furnaces gained popularity for efficiency, low cost, and reliability. By 2017, 95% of EAFs were open-lid; since 2017, over 85% of newly installed furnaces adopted continuous horizontal charging. Consteel furnaces still face issues: preheating temperatures only reach 200–300°C (design 400–600°C), dioxin formation in exhaust gases, and high “wild air” intake affecting dust removal and waste heat recovery.

Quantum, Ecoarc, and Sharc furnaces address these issues through vertical preheating. Quantum uses lifting trolleys instead of baskets, siphon tapping, and maintains high preheating with minimal harmful gases. Ecoarc integrates a sealed vertical preheating system, achieving 800°C scrap preheating and dioxin emissions <0.1 ng-TEQ/m³. Sharc, a DC furnace, also uses dual vertical shafts to preheat scrap, achieving similarly low emissions. Globally, these furnaces are limited in number, with their effectiveness still being evaluated.

Currently, domestic EAF capacity is 85% local and 15% imported. While small furnaces (<100 tons) are largely domestically produced, China is developing proprietary integrated EAF systems, combining horizontal and vertical advantages. CISDI-Green and CERI-s1-Arc furnaces demonstrate innovations such as stepped continuous scrap feeding, dioxin reduction, and waste heat utilization, though still at a promotional stage. Future furnace development will focus on continuous charging, scrap preheating, environmental protection, low dioxin emissions, waste heat recovery, and intelligent steelmaking.

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Key Production Metrics

With advanced technologies, domestic EAFs under full scrap conditions can achieve 30-minute refining cycles, metal yield of 90–92%, power consumption below 300 kWh/ton, electrode consumption below 1.0 kg/ton, and annual nominal capacity exceeding 10,000 tons per ton of furnace.

Current EAF steel costs are 500–600 RMB/ton higher than long-process steel, mainly due to raw materials, power, electrodes, and refractory consumption. Cost reduction relies on optimizing these factors. Expanding scrap imports and reducing iron ore dependence is a practical approach.

Other cost management strategies include:

• Minimizing raw material costs through scrap classification and using diverse iron-rich materials.

• Reducing energy consumption via optimized power supply, preheating, and continuous charging.

• Maximizing off-peak electricity benefits, automation, and minimizing downtime.

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Future Technical Directions

Focusing on efficiency, low consumption, green and intelligent technology, steel enterprises should select suitable furnace types and production technologies. Unlike converters using liquid iron, EAFs use solid scrap, making control more challenging. Future directions include:

• Short-process high-efficiency, low-cost, low-energy production.

• Green key process technologies, including flue gas heat recovery, furnace insulation, low-value wastewater heat utilization, dioxin control, zinc-containing dust utilization, and slag modification.

• Intelligent manufacturing: scrap and furnace charge control, smart electrode adjustment, multi-functional robots, molten pool temperature monitoring, foam slag detection, liquid level monitoring, gas analysis, endpoint control, and one-button or fully automated EAF operation.

• High-value specialty steel metallurgy.

Currently, China’s high-end specialty steel accounts for less than 5%, while Europe, the US, and Japan exceed 20%, with Sweden up to 60%. High-end steels are mostly EAF-produced. As the industry shifts from quantity to quality, material upgrading is urgent, and demand for high-end specialty steels is expected to grow rapidly.

(Author: Professor-level Senior Engineer, Steel Research Institute, China)