Abstract
Particle size of granular materials severely affects the heating behavior under microwave irradiation. Since microwave heating is becoming increasingly used for materials processing, there is a greater demand of more elaborated methods for the dynamic materials characterization during microwave heating.
In this work, quartz sand samples with different particle size (mean diameters from 500μm to 10μm) have been selected to study the effects of the particle size. Quartz sand is the main raw material to manufacture silica film, fused silica glass, semiconductor silicon, fiber optics, etc. It can be thus considered as a representative material for different applications of microwave mineral processing.
To assess these effects, several methodologies have been applied. For example, a relationship has been obtained between the mean particle size and the dielectric properties of samples at room temperature.
Also, a comparison of the temperature curves (up to 1100ºC) of the different samples for a given and controlled microwave power profile in a single mode microwave applicator is provided.
Other characteristics affecting the microwave heating of the samples, such as composition, particles morphology and cristallinity have been also studied and the results have been related to the dielectric properties of the samples, giving a deeper understanding of the processes underlying microwaves and materials interactions.
