Microwave field: High temperature dielectric properties and heating characteristics of waste hydrodesulfurization catalysts.

The exploration of the dielectric properties of waste hydrodesulfurization catalysts has important guiding significance for the development of microwave heat treatment of waste hydrodesulfurization catalysts for the recovery of valuable metals. The resonant cavity perturbation technique was used to measure the dielectric properties of waste catalyst and the mixture of waste catalyst and Na2CO3 during roasting from room temperature to 700 °C at 2450 MHz. The heating properties of the waste catalyst and mixture of waste catalyst and Na2CO3 were determined in the microwave field. The results show that the waste catalyst and the mixture of waste catalyst and Na2CO3 exhibit strong microwave response capability, and the dielectric constant, dielectric loss factor, and dielectric loss tangent increase with increasing temperature; from 20 to 300 °C, the waste catalyst and the mixture of waste catalyst and Na2CO3 heated at a slower rate, while the material heated rapidly from 300 to 700 °C. In addition, the mechanism of microwave action has been proposed based on the study of dielectric properties and heating properties in the microwave field.