Graphite electrodes are the core material in short-process steelmaking (electric arc furnace steelmaking), with their critical roles manifesting in four key dimensions: electrical conductivity and heat transfer, process stability, efficiency enhancement, and environmental adaptability. A detailed analysis is as follows:
I. Electrical Conductivity and Heat Transfer: The “Energy Converter” of Electric Arc Furnaces
Short-process steelmaking primarily utilizes scrap steel as raw material, melting and refining it into steel through electric arc furnaces (EAF). As a conductive material, the core functions of graphite electrodes are:
- Electrical Energy Transmission: Graphite electrodes introduce high-voltage electrical energy into the furnace, generating high-temperature electric arcs (exceeding 4,000°C) between the electrodes and scrap steel, directly melting the scrap.
- Efficient Heat Transfer: The high thermal conductivity of graphite (approximately 100–200 W/(m·K)) ensures rapid heat transfer from the electric arc to the furnace charge, shortening melting times and reducing energy consumption.
- High-Temperature Resistance: Graphite has a melting point exceeding 3,500°C, significantly higher than steelmaking temperatures (approximately 1,600–1,800°C), enabling long-term stable operation without melting and ensuring continuous steelmaking.
II. Process Stability: The “Anchor” in Extreme Operating Conditions
The electric arc furnace steelmaking environment is extremely harsh, and graphite electrodes ensure process stability through the following characteristics:
- Thermal Shock Resistance: Graphite’s low coefficient of thermal expansion (approximately 1–2 × 10⁻⁶/°C) allows it to withstand drastic temperature changes during electric arc startup and shutdown (from room temperature to 4,000°C), preventing cracking or fracture.
- Chemical Stability: Graphite exhibits minimal reactivity with furnace materials (scrap steel, alloys, etc.) at high temperatures, reducing impurity introduction and ensuring steel purity.
- Mechanical Strength: High-strength graphite electrodes can withstand arc forces, impacts from furnace charges, and mechanical stress during handling, lowering attrition rates.
III. Efficiency Enhancement: The “Accelerator” of Short-Process Steelmaking
The performance of graphite electrodes directly impacts steelmaking efficiency and costs:
- High Electrical Conductivity Efficiency: Graphite’s low electrical resistivity (approximately 10⁻⁴ Ω·cm) minimizes electrical energy loss, stabilizes arc combustion, and increases melting speeds by 10%–20%.
- Customizable Specifications: Electrode diameters and lengths can be tailored to meet the needs of electric arc furnaces of different tonnages (e.g., Φ300–400 mm electrodes for small furnaces and Φ700–800 mm ultra-high-power electrodes for large furnaces).
- Optimized Consumption: Technological advancements have reduced graphite electrode consumption per ton of steel from 9.3 kg in 1960 to 2.82 kg in 1994, significantly lowering steelmaking costs.
IV. Environmental Adaptability: The “Key Enabler” of Green Steelmaking
Short-process steelmaking replaces “iron ore + coke” with “scrap steel + electricity,” reducing carbon emissions by approximately 75%. In this context, graphite electrodes:
- Support Clean Energy: They align perfectly with the electric arc furnace’s “electricity replacing coal” model, driving the low-carbon transformation of the steelmaking industry.
- Reduce Pollutant Emissions: Compared to the blast furnace-converter long process, electric arc furnace steelmaking reduces SO₂, NOx, and dust emissions by 60%–80%. As a core component, graphite electrodes contribute to achieving environmental goals.
- Promote Resource Recycling: Scrap steel serves as the direct raw material for graphite electrode applications, forming a closed-loop cycle of “scrap steel-electric arc furnace-graphite electrodes” and enhancing resource utilization.
V. Strategic Value: The “Hard Currency” in the Global Industrial Chain
- Concentrated Supply: Global graphite electrode production capacity is concentrated among a few enterprises in China, such as Fangda Carbon, which accounts for 30% of global capacity. China supplies over 60% of the global market, holding strategic influence.
- High Technical Barriers: Ultra-high-power graphite electrodes require premium raw materials like needle coke and modified pitch, with production cycles lasting 3–6 months. Technical thresholds limit new entrants.
- Geopolitical Impact: In 2025, Japan initiated an anti-dumping investigation into Chinese graphite electrodes, highlighting their strategic importance. China has solidified its market position through agreements like the Regional Comprehensive Economic Partnership (RCEP) while accelerating technological R&D to strengthen industrial chain security.
Conclusion
Graphite electrodes have become an indispensable key material in short-process steelmaking through their four core functions: electrical conductivity and heat transfer, process stability, efficiency enhancement, and environmental adaptability. Technological advancements and supply stability in graphite electrodes not only influence steelmaking costs and efficiency but also profoundly shape the low-carbon transformation and geopolitical dynamics of the global steel industry. With the rising proportion of electric arc furnace steelmaking (China aims for 15%–20% by 2025), market demand and technological innovation for graphite electrodes will continue to accelerate, serving as an “invisible engine” for high-quality development in the steel industry.
Post time: Jul-18-2025