Nippon Steel makes low-grade ore DRI with hydrogen

Nippon Steel Corporation has successfully completed a pilot-scale trial producing direct reduced iron (DRI) using only hydrogen as the reducing agent and lower-grade iron ore as feedstock, the Japanese steelmaker announced on November 4. This is a major step toward commercializing zero-carbon ironmaking, it emphasized.

The trial was conducted at the pilot-scale shaft furnace which stands approximately 60 metres tall with a production capacity of 1 tonne/hour that was commissioned in March this year at Nippon Steel's Hasaki Research & Development Center. Over more than 300 hours of continuous operation, the furnace has produced a cumulative total of more than 1,000 tonnes of DRI, the company announced.

A key breakthrough in the trial was the use of lower-grade iron ore – blast furnace grade pellets (63%-65% Fe grade) – instead of the high-grade direct reduction grade pellets (66%-68% Fe grade) that commercial DRI furnaces typically require. Nippon Steel has adopted upgraded technologies to suppress the powdering tendency of low-grade iron ore during reduction, which adversely affects gas permeability inside the furnace, it said.

The successful use of low-grade iron ore improves the sustainability of future DRI production, since the global supply of high-grade iron ore suitable for conventional reduction technologies is limited, the company underlined.

Another major technical hurdle overcome is the endothermic characteristics associated with reduction reactions using hydrogen alone that can cause the internal furnace temperature to drop easily. To address this challenge, an optimized thermal compensation system is applied, successfully ensuring stable operation throughout the trial.

"Currently, approximately 100 million tonnes of DRI are produced annually worldwide using commercial reduction furnaces powered by natural gas," the company observed. "Because natural gas reduction emits CO₂, the development of hydrogen reduction technology is crucial for decarbonization," it stressed.

"Nippon Steel will continue its hydrogen-based DRI tests at the pilot-scale shaft furnace to establish direct reduction technology and optimize operational conditions," the company said. From fiscal 2027, it plans to advance development including scale-up technologies, aiming to establish commercial implementation technology by around 2040.

Written by Anthea Shi, shihui@mysteel.com

Edited by Russ McCulloch, russ.mcculloch@mysteel.com