järnframställning

Järnframställning, the process of producing iron metal from iron ore, has evolved from ancient smelting techniques to modern industrial methods. Historically, iron was extracted in small furnaces using charcoal and a simple reduction of ore. The discovery of the blast furnace in the Middle Ages marked a turning point, enabling continuous operation and large-scale production.

In contemporary industry, primary iron production takes place in blast furnaces, where iron ore, coke, and limestone are combined in a charged mixture. Coke serves as both fuel and reducing agent, while limestone removes impurities by forming slag. The process yields molten pig iron, which contains high carbon and sulfur levels. Pig iron is usually routed to basic oxygen furnaces (BOF) or electric arc furnaces (EAF) to reduce its carbon content and produce steel. In a lightweight vertical sectionalized “hot reduction” furnace, iron ore is reduced at temperatures exceeding 900 °C using a gas mixture of carbon monoxide and hydrogen, producing direct reduced iron (DRI). DRI can be melted in EAFs for steel production, providing a low‑carbon path especially useful in regions with abundant natural gas.

Environmental concerns focus on energy consumption, CO₂ emissions, and slag disposal. Modern practices incorporate renewable energy sources, carbon capture technologies, and slag recycling into cement production. Regulation and market pressure are driving innovation in more sustainable production routes. The term järnframställning thus encompasses a broad spectrum of technologies, from legacy blast furnace operations to emerging hydrogen‑based direct reduction, reflecting the continuous effort to balance industrial demand with ecological responsibility.