Technique for Measuring the Dielectric Properties of Minerals at MicrowaveHeating Frequencies Using an Open-Ended Coaxial Line

摘要

As part of the research effort on investigating the effects of microwave energyon the chemical and physical properties of minerals and ores, the U.S. Bureau of Mines' Tuscaloosa Research Center has conducted research to measure the dielectric properties of these materials. The objective was to establish a reliable data base for use in predicting the effects of microwave heating on a wide range of minerals. In this phase of microwave research, the Bureau measured the dielectric properties of powdered minerals with medium to high electrical conductivities in the frequency range of 300 MHz to 3 GHz and as a function of temperature, from 25 deg to 325 deg C. Since the minerals were prepared as powders, techniques were used to relate the measured dielectric properties of the powdered minerals to the dielectric properties of the mineral at its theoretical or natural density.