钢铁冶炼从矿石还原产生的排放约占人类活动温室气体排放的8%，超过民航排放量的三倍多。传统工艺用焦炭部分燃烧产生的一氧化碳还原氧化铁会生成 CO₂，而氢基还原气体主要生成水，但还原后铁中的硅、氧化铝和磷等杂质以及吸收的碳仍需后处理，因此更理想的是更清洁的一步法路径。

位于科罗拉多州博尔德的 Electra 采用电沉积法：先用硫酸溶解矿石，再在溶液中电解在约60°C 下将铁沉积成电极上的金属。该公司已从实验室走向500 吨/年的示范装置，计划建设每个模块年产20 万吨的装置，而现代高炉每年通常可达200–400 万吨，因此其目标是通过低温工艺、可用低品位矿石及高附加值产品提升价值并降低前期资本投入。

Boston Metals 的高温法在超过1,538°C 的熔融氧化物中进行电解，实验室阶段曾有效，但其2月在巴西设施（用于铌提取）发生“关键设备故障”后已宣布关闭Woburn工厂，显示从实验到商业放大仍高风险。Hertha 的甲烷热解路线已达实验室每年数百吨产量，计划到2027年底达1万吨，2030年每个模块达到30–50万 吨规模；与大型企业依赖昂贵电解氢还原的做法相比，Electra直接用电减少中间环节，Hertha则采用更便宜的就地氢生成并预留未来切换到电解氢的路径。

Steelmaking from ore reduction accounts for about 8% of anthropogenic greenhouse-gas emissions, more than three times civil aviation emissions. Conventional processes using carbon monoxide from coke combustion produce CO₂, while hydrogen-based reducers mainly produce water, but impurities such as silica, alumina, and phosphorus plus absorbed carbon still require further purification, so cleaner one-step routes are sought.

Electra in Boulder uses electrowinning: it dissolves ore in sulfuric acid and then plates iron via electrolysis at roughly 60°C. It has moved from lab to a 500-tonne-per-year demonstration plant and plans modules of 200,000 tonnes annually, versus modern blast furnaces producing roughly 2–4 million tonnes per year, with the strategy of lower- temperature operation, low-grade ore compatibility, and higher-value products to offset upfront capex risk.

Boston Metals uses molten-oxide electrolysis above 1,538°C, which worked in the laboratory, but after a February critical equipment failure at its Brazil facility during niobium work, it has shut its Woburn operation, underscoring scale-up risk. Hertha’s methane-pyrolysis route already reaches several hundred tonnes per year, targets 10,000 tonnes by end-2027 and 300,000–500,000 tonnes per module by 2030; compared with incumbents using costly electrolysis-produced hydrogen, Electra skips that conversion by using power directly, while Hertha uses cheaper in-house hydrogen and retains a switch path to electrolytic hydrogen if prices fall.

Source: A trio of firms want to clean up steelmaking

Subtitle: The industry is currently responsible for around 8% of the world’s carbon emissions

Dateline: 4月 01, 2026 06:04 上午 | Boulder, Colorado