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.

Kinetics of extraction of nitric acid into binary mixture of tri-n-butyl phosphate and normal paraffin hydrocarbon

Extraction kinetics of nitric acid from the nitric acid-hydrochloric acid-potassium chloride solution by tributyl phosphate

Liquid–liquid equilibrium (LLE) data of the system nitric acid + phosphoric acid + calcium nitrate + water + tri-n-octylamine (TOA) were measured at 298.15 K and atmospheric pressure. The distribution coefficients of nitric acid, phosphoric acid, calcium nitrate, and water and the separation factors of nitric acid against phosphoric acid, nitric acid against calcium nitrate, and nitric acid against the water were calculated. Based on these data, the capability and selectivity of TOA for extracting nitric acid in this system were evaluated. The experimental results were used to obtain binary interaction parameters and pair parameters as correlated by the electrolyte non-random two-liquid (eNRTL) model. The eNRTL model was shown to be suitable for predicting the LLE data of this system, with a root-mean-square deviation of just 1.17%. 

Liquid–Liquid Equilibria of the System Nitric Acid + Phosphoric Acid + Calcium Nitrate + Water + Tri-n-Octylamine at 298.15 K

/pdf/a-kinetic-study-of-nitric-acid-extraction-by-tri-n-21jahegl3j.pdf

Xuhong Jia

Papers

A Kinetic Study of Nitric Acid Extraction by Tri- n -octylamine Abstract