We are rendering coal-powered blast furnaces obsolete by creating new laser furnaces that can provide clean industrial heat for iron and steelmaking. Our Green Steel Printing technology directly manufactures iron and steel objects from iron-oxide powder and green hydrogen gas, without emitting any carbon dioxide. Directed laser heating drives both the iron-oxide to iron reaction and metal deposition into a desired geometry, vertically integrating green ironmaking with additive manufacturing. When scaled up, our laser furnace will also provide green steel beams and sheets for traditional manufacturing. For every ton of steel we produce, 1.8 tons of carbon-dioxide emissions are eliminated. In 2050, we project that 8% of the commodity steel market (346 million tons) will source zero-emissions steel using our technology, eliminating 623 million tons of carbon-dioxide per year.