Process for producing foaming slag to feed the arc furnace using plasma burner, induction furnace, and microwave heating device.

Abstract

The invention proposes an integrated process for the reduction of iron ore and the production of foaming slag intended for electric arc furnaces.The process begins with the introduction of a mixture of iron ore and carbon into a microwave furnace, where it is heated to 1000°C to initiate a first chemical reduction. The heated mixture is then transferred into an inclined refractory tube, where it is combined with slag heated to 1600°C, produced using an induction furnace. A plasma burner operating with nitrogen or hydrogen, positioned between the induction furnace and the microwave furnace, keeps the mixture in a liquid state throughout the process. This method ensures continuous and efficient reduction of iron ore in the presence of the foaming slag.Finally, the reduced ore and the foaming slag are directed and introduced into the electric arc furnace for the final stage of the process.The primary objective of this invention is to introduce an alternative source of foaming slag into the arc furnace, thereby reducing the 10 to 20 minutes typically required for slag formation. It also provides an additional source of pure iron, contributing to the improvement of the final product's quality.This invention does not replace the lime, carbon, and oxygen injectors in the arc furnace, but it enables a reduction in oxygen consumption, thus limiting its harmful effects on the furnace. Moreover, it shortens the "tap-to-tap" cycle time through the addition of liquid steel produced by the direct reduction of iron oxide, accounting for up to 30% of the input material.