Leaching kinetics of synthetic CaWO_4 in HC1 solutions containing H_3PO_4 as dictating agent

摘要

In this study, the dissolution kinetics of synthetically prepared CaWO_4 in HC1 solutions containing H_3PO_4 was studied. The effects of process parameters such as stirring speed, temperature and acid concentrations on the dissolution rate of CaWO_4 were investigated. The reaction rate was found to be of 1 /3 and 2/3 order with respect to HC1 and H_3PO_4 concentrations, respectively, and the activation energy for the dissolution reaction to be 60 kJ moF~(-1). The rate equation for the dissolution reaction was derived using the Avrami equation and the rate determining step was the chemical reaction on the surface of solid particles.