Drying kinetics of thorium oxalate: Experimental investigation and modeling

Highlights: •Drying kinetics of thorium oxalate was studied at temperature range of 353–393 K. •It was found that the moisture transfer was dominated by internal diffusion mechanism. •Balbay and Sahin model was in the best agreement with the experimental data. •The effective moisture diffusivity of thorium oxalate was measured. •The activation energy of moisture diffusion was found to be 11.21 kJ/mol. -- Abstract: In the present study, the drying behavior of thorium oxalate in the temperatures range of 353–393 K was studied to determine drying kinetics and effective moisture diffusivity. Thirteen widely used semi-theoretical thin-layer drying models with temperature-dependent constants were selected to describe the drying kinetics. The results revealed that all examined models were acceptable, but Balbay and Sahin model was the best for describing drying kinetics of thorium oxalate. Moreover, the effective moisture diffusivity in the temperature range of 353–393 K varied from 3.68 × 10⁻⁹ to 5.47 × 10⁻⁹ m²/s. In addition, the drying activation energy was found to be 11.21 kJ/mol.