Process and kinetics study on hydrolysis for the generation of Ti/W powders with controlled pore properties

The lack of research on the hydrolysis and calcination processes in the low-concentration Ti-W-H2SO4 system has hindered the recovery of titanium from H2SO4 waste solution. This paper presents a feasible process for the preparation of Ti/W powders from unconcentrated H2SO4 solutions containing Ti and W. The kinetics of hydrolysis and the effects of process parameters on the properties of Ti/W powders were studied. Under optimum conditions, a Ti/W powder with a total TiO2 and WO3 content of 97.49%, a specific surface area of 89.40 m2/g was obtained. The resynthesized SCR catalysts prepared using Ti/W powder show good denitrification activity. The hydrolysis efficiency of Ti conforms to the Avrami model. The homogeneous nucleation reaction occurred during hydrolysis with an activation energy of 191.97 kJ/mol. Based on the kinetic research, the temperature and time can be adjusted to achieve a fine tuning of the microscopic morphology, pore properties, and particle size of the powder particles. This study demonstrates an effective method for the stable preparation of high-value products from low-concentration Ti-W-H2SO4 solutions, which contributes to environmentally friendly resource recovery.