Product

Metallurgical coke is a solid, porous, high-carbon material produced by the destructive distillation (carbonization) of low-ash, low-sulphur bituminous coal (coking coal) at temperatures of 900–1,100°C in the absence of air. During carbonization, volatile matter is driven off, leaving behind a fused, cellular carbon structure with high mechanical strength and thermal stability. The residue obtained from carbonizing non-coking coals such as sub-bituminous coal, lignite (brown coal), or anthracite is distinct and is referred to as char.

Coke's principal constituent is carbon, with minor amounts of mineral matter (ash) and residual volatile matter. Its key functional properties — high compressive strength, low reactivity, and high porosity — make it uniquely suited for use as a fuel, reductant, and structural support medium in the blast furnace. In iron and steel making, coke serves three simultaneous roles: it provides the thermal energy required for smelting, it generates carbon monoxide (CO) as the primary reducing agent for iron ore, and it physically supports the burden of iron ore and limestone in the blast furnace shaft. Since coke is a fundamental raw material in the production of pig iron — which is in turn the primary input for steel manufacturing — integrated steel plants typically operate their own Low Ash Metallurgical (LAM) coke plants on-site to secure supply and quality control.

Grades

Metallurgical coke is produced in several grades according to end-use requirements:

• Blast Furnace Coke — the largest-volume grade; requires high mechanical strength (CSR >60%), low reactivity (CRI <25%), low ash (<10%), and low sulphur (<0.7%) to support efficient blast furnace operation
• Foundry Coke — larger lump size, higher carbon content, and lower sulphur than blast furnace coke; used in cupola furnaces for iron casting
• Ferro-Alloy Coke — used as a reductant in the production of ferro-alloys (ferro-manganese, ferro-silicon, ferro-chrome); typically requires very low ash and specific reactivity characteristics
• Other Chemical/Industrial Grades — used in calcium carbide production, phosphorus smelting, and other electrochemical reduction processes

Chemical & Physical Data

Key Quality Parameters

References

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