Effect of microwave drying technology on drying kinetics of Al2O3–ZrO2 composite ceramic powder

Abstract

Al2O3–ZrO2 composite ceramic is a significant structural material and functional material, and the preparation of high-quality Al2O3–ZrO2 powder is a key step to meeting practical application requirements. The major factor affecting the quality of Al2O3–ZrO2 powder is the drying effect. This paper uses modern microwave drying technology to dry Al2O3–ZrO2 powder. The result was indicative that the average drying rate increases with initial moisture content, initial mass, and microwave heating power. Four dynamic models were applied to fit the empirical data of Al2O3–ZrO2 powder under different pretreatment conditions, the Modified Page model can precisely delineate the Al2O3–ZrO2 microwave drying procedure. To evaluate the changes in samples before and post-drying, the specimens were characterized by Fourier transform infrared spectroscopy. These results demonstrate that microwaves can accelerate the drying of Al2O3–ZrO2 and improve its dispersion. Fick's second law calculates the effective diffusion coefficient. When the initial moisture content of Al2O3–ZrO2 was 5.6%, the microwave heating power is 560 W, and the initial quality is 15 g, the effective diffusion coefficient of Al2O3–ZrO2 is 0.006361 m2/s. Based on the relevance of the microwave power and activating energy, the activating energy of microwave drying Al2O3–ZrO2 was calculated, which is −34.80 g/W. This paper provides basic study data and theory instructions for microwave drying technology in drying Al2O3–ZrO2 even the drying process in green metallurgy.

Keywords

• Al2O3–ZrO2 power
• Microwave drying
• Kinetic models
• Drying rate
• Activation energy