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

Abstract

The lack of research on the hydrolysis and calcination processes in the low-concentration Ti-W-H2SO4 system has been an obstacle to the recovery of titanium from the H2SO4 waste solution. This study proposes a feasible process for the synthesis of Ti/W powders from unconcentrated H2SO4 solutions containing Ti and W. The study explores the kinetics of hydrolysis and the influences of process parameters on the properties of Ti/W powders. Under optimum conditions, a Ti/W powder with a total TiO2 and WO3 content of 97.49%, and a specific surface area of 89.40 m2/g was obtained. The resynthesized SCR catalysts prepared using Ti/W powder demonstrated 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 fine-tune the microscopic morphology, pore properties, and particle size of the powder particles. This study demonstrates an effective technique for the stable preparation of high-value products from low-concentration Ti-W-H2SO4 solutions, which contributes to eco-friendly resource recovery.