What key role does graphitized petroleum coke play in the short process and low-carbon smelting of electric arc furnaces?

The Key Roles and Analysis of Graphitized Petroleum Coke in Electric Arc Furnace (EAF) Short Process and Low-Carbon Steelmaking

I. Core Raw Material for Graphite Electrodes, Supporting Efficient Operation of EAF Short Process

1. Raw Material Characteristics and Process Compatibility Graphitized petroleum coke is a product derived from petroleum coke subjected to graphitization at temperatures exceeding 2,500°C, transforming its crystal structure from an amorphous state to a highly ordered graphite form. It exhibits high electrical conductivity, high thermal conductivity, extreme heat resistance (withstanding temperatures above 3,000°C), and chemical stability. These properties make it an ideal raw material for producing graphite electrodes, which are the core conductive components in EAF steelmaking.

2. Efficiency Improvements in Short-Process Steelmaking The EAF short process primarily uses scrap steel as feedstock, melting it directly and oxidizing impurities through electrical arcs generated by graphite electrodes. Compared to the traditional blast furnace-basic oxygen furnace (BF-BOF) long process (which requires iron ore and coking coal), the EAF short process eliminates the ironmaking stage, reducing process length by over 60%, cutting energy consumption by nearly 60%, and lowering CO₂ emissions by approximately 80%. Graphitized petroleum coke-based high-performance graphite electrodes play a pivotal role in this process:

• High Electrical Conductivity: Minimizes electrical energy loss, enhances arc thermal efficiency, and shortens smelting cycles (e.g., quantum EAFs reduce smelting time by 50% compared to conventional methods).
• Heat Resistance: Withstands extreme temperatures inside EAFs, reducing electrode consumption (e.g., eco-EAFs cut electrode consumption by 57.5% versus traditional furnaces).
• Chemical Stability: Prevents reactions between electrodes and molten steel or slag, ensuring steel purity.

II. Driving Low-Carbon Steelmaking: Green Transformation from Raw Materials to Processes

1. Replacing Fossil Fuels to Reduce Carbon Emissions The traditional long process relies heavily on coal as a fuel and reducing agent, resulting in high carbon intensity. In contrast, the EAF short process uses scrap steel and electricity as its energy source, achieving “coal-to-electricity” substitution via graphitized petroleum coke-derived graphite electrodes. If powered by renewable energy (e.g., solar or wind), near-zero carbon emissions become feasible. For instance, eco-EAFs employ green energy to smelt low-carbon raw materials, producing steel billets with “non-carbon-involved” technologies and nearly zero CO₂ emissions.

2. Waste Heat Recovery and Energy Efficiency Optimization The high thermal conductivity of graphitized petroleum coke supports the implementation of waste heat recovery systems in EAFs. High-temperature dust-laden flue gases (carrying away 11–20% of input energy) can recover heat via graphite electrodes or dedicated heat exchangers for scrap preheating or power generation, significantly reducing energy consumption. For example, scrap preheating technology raises scrap temperatures from ambient to over 600°C, shortening smelting cycles by 15–20% and cutting electricity consumption per ton of steel by 36.95–40.22%.

3. Promoting Circular Use of Scrap Steel Resources The EAF short process, powered by graphitized petroleum coke, shifts the steel industry from a linear “resources-products-waste” model to a circular “resources-products-recycled resources” framework. By 2024, leading companies achieved mass production of ultra-thin, ultra-high-strength automotive hot-stamping steels, meeting lightweighting demands while balancing the cost and environmental benefits of “green steel.”

III. Technological Upgrades and Market Trends: The “Gray” Value of Graphitized Petroleum Coke Shines

1. Growing Demand for High-Performance Products As EAF capacities expand (e.g., furnaces exceeding 400 tons) and smelting technologies advance (e.g., quantum EAFs, eco-EAFs), demand for high-quality graphite electrodes rises. Graphitized petroleum coke, as a critical raw material, faces heightened competition over purity (ash content <0.5%), multiple impregnations (3–4 cycles), and ultra-high-temperature graphitization (resistivity <4 μΩ·m).

2. Green Premium and Supply Chain Integration Under China’s “dual carbon” goals, graphitized petroleum coke producers reduce carbon footprints through green energy production and carbon trading, earning “green premiums” and attracting international high-end clients. Leading firms are also extending vertically to form integrated industrial loops spanning “coke raw materials-graphitization-anode materials,” stabilizing supply chains and cutting costs.

3. Policy and Market-Driven Growth Policies like China’s Guidelines on Promoting High-Quality Development of the Steel Industry explicitly encourage EAF adoption, with EAF steelmaking ratios projected to rise significantly by 2025. As a core raw material for EAFs, graphitized petroleum coke will see sustained market growth, driving the industry toward higher performance and lower emissions.