Use of ultrasound in the dissolution kinetics of phosphate rock in HCl

The dissolution kinetics of phosphate ore in HCl solutions is investigated in the absence and presence of ultrasound. The particle size, reaction temperature, acid concentration and amplitude of ultrasound power were chosen as parameters. The reaction is first order with respect to H+ and activation energy equal to 18 kJ/mol in both cases. The effect of ultrasound is on the pre-exponential factor A. An empirical relation is given which relates rate constant to ultrasound power.