To cite this article: Masry, B. A. et al. (2018). Liquid-liquid extraction and recovery of Pd(II) from nitric acid medium using green diesel as extractant. J. Phys. Sci., 29(2), 25–48, https://doi.org/10.21315/jps2018.29.2.3
A cost-effective method for the extraction of palladium (Pd) from HNO3 solution by green diesel as extractant in kerosene was investigated. Several parameters such as extractant, nitrate, hydrogen ion, nitric acid and metal ion concentrations, phase ratio, and thermodynamic parameters were studied. The extracted species were deduced using slope analysis method and infrared (IR) measurements. The results showed that the extraction efficiency of Pd(II) is 95% with 10% (v/v) diesel in kerosene, and 97% was recovered from the loaded organic solution using 0.05 M thiourea or ammonium thiocyante solutions as stripping agents. The maximum loading capacity of diesel was found to be 2 × 10−2 moles of Pd(II) per mole extractant. The effect of diluents on the extraction of Pd(II) from nitric acid solution by green diesel indicated that, under the used experimental conditions, kerosene gave the highest extraction percent compared to cyclohexane, benzene, toluene, chloroform and carbon tetrachloride. Extraction of Pd(II) from different acidic media was also carried out and the extraction percent was found to decrease in the order: H2SO4 > HNO3 > HCl. The possibility of extraction and recovery of Pd from the sulphate leach solution of spent automotive catalyst was explored and a modified process is proposed and evaluated.