The extraction kinetics of nitric acid with tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbon (NPH) was investigated. Experiments were carried out in a constant area stirred cell. Influences of stirring speed, temperature, specific interfacial area and concentrations of extractant and nitric acid on the extraction rate of nitric acid were studied. The objective of the present study was to identify the reaction location, extraction reaction regime and to determine intrinsic rate constant of the reaction and mass transfer coefficients. A systematic approach was adopted for the determination of these rate parameters. Based on experimental results, it is concluded that the liquid-liquid reaction takes place at the interface and the overall rate is controlled by both the intrinsic kinetics as well as the mass transfer of the species involved. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.