How did the Linz-Donawitz basic oxygen process improve steelmaking?

The Linz-Donawitz (LD) process, developed in Austria in 1949, revolutionized steelmaking by utilizing high-purity oxygen to significantly increase production speed and efficiency compared to traditional methods like the open-hearth furnace.12

Key improvements included:

• Increased Speed: By blowing oxygen at supersonic velocity through a lance into the top of a converter, the process eliminated the cooling effect of nitrogen found in air-blown methods. This allowed for rapid oxidation of elements, reducing the time required to refine a charge to as little as 15 to 20 minutes.31
• Scrap Utilization: Because the process did not rely on air, the heat generated was sufficient to melt significant amounts of scrap metal added to the pig-iron charge, increasing resource efficiency.1
• Enhanced Refining: By adding lime to the charge, the process created a basic slag capable of effectively removing phosphorus and sulfur, which was a major limitation of earlier steelmaking technologies.1
• Scalability: The process enabled the production of large quantities of steel—up to 400 tons per heat—eventually replacing older, slower methods like the open-hearth and Bessemer processes globally.12