Abstract The major objective of this work was to investigate the effects of temperature and moisture content on the dielectric properties of silica sand. The dielectric properties of moist silica sand at five temperatures between 20 to 100 °C, covering different moisture content levels at a frequency of 2.45 GHz, were measured with an open-ended coaxial probe dielectric measurement system. The wave penetration depth was calculated based on the measured dielectric data. The results show moisture content to be the major influencing factor for the variation of dielectric properties. Dielectric constant, loss factor and loss tangent all increase linearly with increasing moisture content. Three predictive empirical models were developed to relate the dielectric constant, loss factor, loss tangent of silica sand as a linear function of moisture content. An increase in temperature between 20 to 100 °C was found to increase the dielectric constant and loss factor. The penetration depth decreased with increase in moisture content and temperature. Variation in penetration depth was found to vary linearly with decrease in moisture content. An predictive empirical model was developed to calculate penetration depth for silica sand. This study offers useful information on dielectric properties of silica sand for developing microwave drying applications in mineral processing towards designing better microwave sensors for measuring silica sand moisture content.

中文翻译：

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硅砂介电性能的温度和水分依赖性

摘要 这项工作的主要目的是研究温度和水分含量对硅砂介电性能的影响。湿硅砂在 20 至 100 °C 之间的五个温度下的介电特性，涵盖了频率为 2.45 GHz 的不同水分含量水平，使用开放式同轴探针介电测量系统进行测量。基于测得的介电数据计算波穿透深度。结果表明，水分含量是介电性能变化的主要影响因素。介电常数、损耗因数和损耗角正切都随着水分含量的增加而线性增加。开发了三个预测经验模型，将硅砂的介电常数、损耗因子、损耗角正切与含水量的线性函数联系起来。发现温度在 20 到 100 °C 之间增加会增加介电常数和损耗因子。渗透深度随着水分含量和温度的增加而减小。发现渗透深度的变化随着水分含量的降低而线性变化。开发了一个预测经验模型来计算硅砂的渗透深度。这项研究提供了有关硅砂介电特性的有用信息，用于开发矿物加工中的微波干燥应用，以设计更好的微波传感器来测量硅砂水分含量。发现渗透深度的变化随着水分含量的降低而线性变化。开发了一个预测经验模型来计算硅砂的渗透深度。这项研究提供了有关硅砂介电特性的有用信息，用于开发矿物加工中的微波干燥应用，以设计更好的微波传感器来测量硅砂水分含量。发现渗透深度的变化随着水分含量的降低而线性变化。开发了一个预测经验模型来计算硅砂的渗透深度。这项研究提供了有关硅砂介电特性的有用信息，用于开发矿物加工中的微波干燥应用，以设计更好的微波传感器来测量硅砂水分含量。