Effect of cavity's geometry and pellet shape on the electric field distribution and penetration depth of microwave in processing electric arc furnace dust

Abstract

Microwave heating has a great potential application in pyrometallurgy because the usual steelmaking materials can interact with microwaves and generate heat. Thus, the penetrating ability and distribution of microwaves inside the materials affect the stability and efficiency of the overall heating process. This paper focuses on electric arc furnace dust (EAFD) as the raw material, the effects of the cavity's geometry and pellet shape on microwave penetration depth and distribution at a frequency of 2.45 GHz have been studied. The results are as follows: (1) Combining the Bruggeman practical medium theory (Br-EMT) and semi-qualities analysis of X-ray diffraction (XRD), the dielectric properties of EAFD can be determined; (2) Cavity has a geometry of regular hexahedral prism can improve the microwave penetration and uniform of distribution; (3) Ellipsoidal pellets (polar radius = 1/2 equatorial radius) make the stock column more easily penetrated by microwaves and keep a uniformed microwave distribution internal.