The Influence of Dielectric Properties on Heating of Sulphide Ores in Electromagnetic Field

Abstract

Microwave heating is a form of high-frequency electromagnetic radiation. The heating of primary and secondary mineral raw materials in the microwave field depends primarily on their dielectric and thermal properties. The condition is the absorption of microwave radiation. Dielectric heating of materials occurs immediately after placing them in an electric high-frequency field. Knowledge of the dielectric characteristics of mineral raw materials is an important assumption for the use of electromagnetic radiation at the intensification of technological treatment methods. Most mined minerals consist of several mineral components that have different dielectric properties. Most sulphides are well heated in a microwave field. Conversely, tailings components of ores, such as quartz, are transmission materials. The study of dielectric properties involves measurements of the complex relative permittivity ε*, which consists of a real and an imaginary part. The imaginary part of permittivity “loss factor” represents the measure of dielectric losses in the material. Microwave heating of sulphide ores and concentrates such are chalcopyrite, tetrahedrite, galena depends on their chemical composition and content of impurities. The article describes the influence of dielectric properties on heating of chalcopyrite in microwave field. SEM analyses of studied samples are presented.