Enhancement of electric arc furnace dust by recycling to electric arc furnace

Electric arc furnace (EAF) dust is a hazardous waste product of the steelmaking industry with a high concentration of heavy metals, especially Zn and Pb. Existing treatment processes are industrially viable only when the zinc content is sufficiently high. In this research we present an industrial-scale process to enhance EAF dust by recycling it to the same furnace in which it was generated. This process, called RECUMET(R), involves two parts: (1) the manufacturing of self-reducing briquettes composed of dust from the steelmaking process, reducing agents and agglutinant agents; and (2) the loading of the briquettes into the EAR Several tests have been performed to improve the chemical, mechanical and thermal properties of the briquettes. These include determinations of compressive, breaking and abrasion strength, softening and melting points, and thermal behavior. The theoretical energy balance calculated from the process of loading briquettes into the EAF has yielded a positive value of similar to 5 X 10(5) kcal/t of briquettes, showing that extra energy is clearly supplied to the furnace. Results corresponding to trials in the EAF are also shown. These include data on taps, slags, energy consumption and the quality of new dust.