Effect of ultrasound on the dissolution kinetics of phosphate rock in HNO3

Ultrasound is known to enhance solid/liquid reactions. This paper deals with the investigation of the dissolution of phosphate rock in nitric acid, in the absence and presence of ultrasound. The reaction is first-order with respect to H+ and activation energy equal to 16 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.