Electric arc furnaces are giant pots that melt steel. They enable the recycling of scrap steel. Recycled steel both costs far less than creating steel from raw materials and has a lower environmental impact.
The process involves three-phase electrodes which create an arc that reaches about 3000°C (5400°F).
Frenchman Paul Héroult (co-inventor of aluminum smelting) perfected using electricity to melt iron. Eventually, he licensed his arc furnaces to US Steel and Halcomb Steel Company. Arguably, Siemens 1857 regenerative furnace and Moissan’s 1892 furnaces are predecessor technologies.
In a familiar pattern, Heroult invented the arc furnace in France but commercialized it in the US. Most furnaces were installed at US Steel.
Undoubtedly, electric arc furnaces always had some utility. Eventually, they became vastly more profitable when combined with the Nucor Mini-Mill innovation.