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

Ultrasound is known to enhance solid/liquid reactions. This paper deals wit h the investigation of the dissolution of phosphate rock in nitric acid, in the absence and presence of ultrasound. The reaction is first-order with r espect to H- and activation energy equal to 16 kJ/mol in both cases. The ef fect of ultrasound is on the pre-exponential factor A. An empirical relatio n is given, which relates rate constant to ultrasound power. (C), 2001 Else vier Science B.V. All rights reserved.