Dielectric Properties of High-Silica Sand at 2.45 GHz

In the paper, presented are measurements of permittivity (εr) and dielectric loss factor (tgδ) of high-silica moulding sand, determined at 2.45 GHz by perturbation method on a stand of waveguide resonance cavity. Determined were electrical properties of the main component of moulding sands, i.e. high-silica base, critical for their heating kinetics. The measurements were carried-out for six kinds of high-silica sand with diverse grain size distribution. Analysis of the results indicates that both permittivity and loss tangent values are similar for all kinds of high-silica moulding sand. Irrespective of their grain size analysis, neither of the examined sandmixes shows susceptibility to action of 2.45 GHz microwave field. The presented results make a ground for developing a mathematical model of microwave heating of technological systems composed of moulding sand and foundry tooling.