HOT METAL FROM OXYGEN CUPOLA FURNACES AS AN ALTERNATIVE CHARGE MATERIAL FOR ELECTRIC-ARC FURNACES

Objective. The increasing share of electric steel in relation to total steel production gives cause for expectation that the prices of scrap will continue to rise. Additional cost-cutting measures are necessary in order to guarantee the competitiveness of electric steel making. T he charging of hot metal can provide a way of achieving this goal. The I following article is intended to show how the charging of hot metal can reduce the cost of electric steelmaking as well as the environmen tal pollution. Summary. Electric arc furnace operating data reveal tha t hot metal charges of 20 to 30% well permit power consumption figures of less than 300 k Wh/t liquid steel. At the same time, they make it possible to shorten the tap-to-tap times by 12 to 15 minutes. Power co nsumption figures of less than 200 k Wh/t liquid steel are expected fo r hot metal charges amounting to more than 45%. By charging hot metal and injecting oxygen at rates up to 50 m(3) (normal state)/t liquid st eel, electric steel-making becomes more similar to the metallurgical p rocess technology of basic oxygen steelmaking. This is also evidenced by lower nitrogen concentrations and a good level of dephosphorisation . The charging of hot metal from oxygen cupola furnaces also permits e ffective off-gas cleaning at reasonable costs. This creates the precon ditions for processing impure scrap grades and makes it possible to li ghten the workload of the EAF gas cleaning systems.