Thin layer modeling the drying kinetics of titanium slag under microwave-assisted drying

High moisture content of titanium slag renders it unsuitable for producing titanium dioxide chloride and titanium sponge in industrial settings. Microwave heating were employed to investigate the impact of initial mass, microwave heating power, and initial water content on the drying process of titanium slag. The results demonstrated positive correlation between the average drying rate and these three variables. Titanium slag weighing 30 g, subjected to microwave heating power of 400 W, and possessing water content of 15 %, was fitted using Page, Wang, Singh, Two-term exponential, and Quadratic models. The findings unequivocally supported the superiority of the Page model in elucidating the microwave drying, which can also be extended to encompass other experimental parameters. By utilizing Fick's second law, the effective diffusion coefficient was computed, revealing an increase followed by subsequent decrease concerning initial mass, while increasing in tandem with microwave heating power and initial water content. Correlation analysis between activation energy and microwave power disclosed an activation energy of -9.94 g/W for the drying of titanium slag. This research provides a valuable reference for the drying of materials, facilitating the more efficient employment of microwave technology in drying metallurgical and chemical raw materials.(c) 2023 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights reserved.