Continuous improvement of DRI technology in the Mittal Steel Company

The Mittal Steel Company is now the world's largest producer of steel and the largest producer/consumer of DRI. The company produces 10 million t of DRI annually by various routes-gas based (Midrex, HyL) and coal based (rotary kilns). The great majority of DRI is consumed internally in EAFs. Major modifications developed during the last ten years have increased the actual gas based DR plants capacity by 33% over the design. Technologies such as pellet coating, oxygen injection, high bustle gas temperature, natural gas direct-to-furnace injection and other modifications have been implemented in our plants. This level of improvement requires implementation of special calculations, computer-based models and tests to support modifications and evaluate results. The paper will describe the technological and process developments that have lead to world-class performance at Mittal Steel Company's DR plants.