Indian steelmakers' increasing adoption of stamp-charging technology is reshaping the country's coking coal demand profile, allowing mills to use lower-quality domestic and imported coals without significantly compromising coke quality.
Indian blast furnaces previously relied on top-charging technology, which required high-fluidity, low-ash coals — sourced largely from Australia — to maintain coke strength and furnace stability. Rising input costs, alongside constraints around domestic coal quality have encouraged some mills to explore investments in stamp-charging systems, market participants said. These systems allow coal blends to be compacted ahead of carbonisation.
Stamp-charging enables steelmakers to use coal blends with the lower fluidity and higher ash content typical of Russian and domestic Indian coals. By increasing coal density before coking, mills can partially offset the negative impact of the coal chemistry on coke strength after reaction (CSR).
Stamp-charging is no longer a niche solution but a core component of India's raw material strategy, market participants said. "Without stamp-charging, Indian mills would struggle to absorb the volumes of non-Australian coal now entering their blends," a steelmaker said.
Blending trends between 2021 and 2024 reflect this shift. The share of premium hard coking coal has declined to around 35pc from 45pc, while hard coking coal (HCC) and semi-soft coals now make up nearly half of the blend. Mills are particularly relying on Russian high volatility coals to compensate for the low fluidity of domestic material, another steelmaker said.
India's domestic coking coal remains challenging to use. Most local reserves contain ash levels between 40-45pc, significantly higher than imported alternatives. When used in high proportions, such coal can reduce CSR and destabilize blast furnace operations. While washing can lower ash levels, capacity limitations and logistics constraints continue to restrict the availability of beneficiated coal.
Domestic production has risen sharply in recent years, but volume gains have not translated into equivalent quality improvements, market participants said. "You can produce more coal, but without washing and evacuation, it doesn't solve the furnace problem," a source said during a panel discussion at the Coaltrans India 2026 conference.
Stamp-charging has helped mills to work around these limitations, but the technology is not a universal solution. It requires higher capital expenditure and operational expertise, making it more suitable for larger integrated steel plants. Smaller mills without access to stamp-charging remain more exposed to fluctuations in premium coal prices.
This technological divide is also influencing the merchant coke market. An estimated 30pc of India's merchant coke capacity can produce 65 CSR coke, offering some relief to mills unable to optimize their own blends. Imported coke remains price-competitive, even after the anti-dumping duties imposed on met coke for the first half of 2026.
Looking ahead, stamp-charging adoption is expected to accelerate as India pursues aggressive infrastructure-led growth. The government has earmarked 12.2 trillion rupees in its 2026-27 federal budget for infrastructure spending, driving expectations of higher steel consumption and hot metal output.
Indian steelmakers will need to maximize flexibility in their cokemaking operations as the country's steel production targets rise toward 300mn t/yr by 2030.
