As a carbon-increasing agent for steelmaking, what kinds of alternative materials are competing with calcined petroleum coke?

Calcined petroleum coke (CPC), as a traditional carburizer, is currently facing multi-faceted competition from graphitized products with superior performance, alternative raw materials with greater cost competitiveness, and novel composite alloy materials. The focus of this competition is mainly on carburizing efficiency, product quality (particularly sulfur and nitrogen content), and overall cost-effectiveness.

1. Performance-Upgrade Competition: Graphitized Carburizer

This is the primary competitor for CPC in high-end applications, especially in the production of ductile cast iron where quality requirements are stringent.

• Core Advantages: Graphitized carburizer is processed at temperatures exceeding 2200°C, transforming the carbon atom arrangement from disordered to an ordered graphite structure. This structural advantage gives it a higher carbon absorption rate (over 90%, compared to CPC’s approximately 85%), extremely low sulfur content (typically below 0.05%), and significantly reduced nitrogen content, which effectively prevents defects like nitrogen porosity in castings and substantially improves casting quality.
• Competitive Landscape: Historically, graphitized carburizer had a clear market segmentation from CPC due to its higher cost. However, in recent years, driven by sharp fluctuations in petroleum coke raw material prices, the price gap between the two has narrowed dramatically. In some periods, graphitized carburizer has even become more cost-competitive, severely squeezing CPC’s market space.

2. Cost-Driven Competition: Calcined Anthracite

In scenarios with less demanding requirements for cost and carburizing performance, calcined anthracite is a strong alternative.

• Core Advantages: High overall cost-effectiveness. Research and practical applications show that under conditions where the unit consumption does not exceed 2 kg per ton of steel, the carburizing effect of calcined anthracite is comparable to that of petroleum coke, with no adverse effects on steel quality. At present, high-quality anthracite carburizers have been widely adopted as substitutes for CPC in many large steel mills and foundries.
• Competitive Landscape: Primarily, it competes in the mid-to-low-end market segments or in steelmaking and gray iron casting production where requirements for trace elements like sulfur and nitrogen are less strict, gaining market share through cost advantages.

3. Functional Composite Competition: Mn-C / Al-Mn-C Alloy Briquettes

This represents a novel form of competition that moves beyond the concept of a “single-function carburizer.” It combines carburizing with deoxidation and alloying functions.

• Core Advantages: Multi-functional and lower overall cost. For example, Al-Mn-C alloy briquettes not only add carbon but also simultaneously achieve deoxidation and partial alloying (with manganese). In practical applications, using 1.5 kg of Al-Mn-C alloy briquettes can replace 1.5 kg of carburizer, 0.5 kg of Si-Al-Fe, and 0.5 kg of Si-Mn-Fe, reducing direct costs by over RMB 8 per ton of steel.
• Competitive Landscape: By offering high and stable carbon recovery rates (up to 95% or more) and simplified smelting processes, this product category poses a direct challenge to traditional single-function carburizers.

4. Long-Term Strategic Competition: Biochar and Other Renewable Carbon Sources

While currently mostly at the R&D and pilot-application stage, this represents the future direction of sustainable development.

• Core Advantages: Environmental friendliness and renewability. In processes like iron ore pelletizing, biochar—produced by pyrolyzing biomass such as straw—is being studied as a substitute for traditional carbon additives like coke fines, aiming to reduce dependence on fossil fuels.
• Competitive Landscape: Currently focused on specific process stages, it has not yet posed a widespread threat to CPC’s mainstream position, but its development potential warrants attention.

Summary

In summary, calcined petroleum coke is facing comprehensive competition from graphitized products on the “quality” high-end, from anthracite carburizers on the “cost” mid-to-low-end, and from composite alloy briquettes on the “functionality” dimension, leading to a continuously shrinking market space. This competitive pressure is intensifying, particularly against the backdrop of shifting cost and performance advantages.