800MM GRAPHITE ELECTRODES - A SOLUTION FOR MORE POWERFUL ELECTRIC STEEL PRODUCTION

摘要

Late in 1999 Peiner Traeger GmbH ran several feasibility studies in its ongoing efforts to ensure competitiveness and profitability by increasing the productivity by 20 percent with comparable or improved cost efficiency. One project focused on fully using the electrical transformer capacity of 140 MVA with a maximum current level of 140 KA. Peine's partner for the supply of 750 mm electrodes since the start-up of the steelplant in 1995, SGL CARBON, joined the project. The objectives were defined quickly: Develop an 800 mm graphite electrode that meets the increased requirements of the steelplant and implement its operation. The joint project from initial discussions between Peine and SGL to start-up of operation with this supersize graphite electrode took around one year including process optimization review and investment activities at Peine and graphite electrode/ nipple and accessories development at SGL CARBON. In January 2001 a new chapter in electric steel melting was opened when the DC-furnace at Peiner Traeger commenced operation with 800 mm electrodes. The great success of the project was confirmed by quickly reaching the anticipated performance targets. The electrode consumption was reduced by approx 5 percent under comparable operating conditions. Applying the full transformer capacity of 140 MVA the power-on time was reduced by 10 percent while electrode consumption figures at currents of 130 and 140 KA remained well below the 1kg/ t benchmark. During the presentation highlights of the project and results will be discussed in detail. The experience gained at Peine can be transferred to operations in Asia as well, not only limited to furnaces already using 750 mm electrodes, but also to furnaces with 700 mm.