The solvent extraction of bismuth (III) from nitric acid solutions with two different extractants, tri-n-butylphosphate (TBP) and Di (2-ethylhexyl) phosphoric acid (D2EHPA) in n-heptane were investigated under different experimental conditions that could affect the beneficiation of bismuth metal. The effect of the following parameters; acid concentration, extractant concentration, temperature, pH and contact time were studied. The observed optimum conditions were applied to the extraction of bismuth (III) from its ore. From the equilibrium studies carried out at a contact time of 25 minutes, extractant concentration at 20 % volume/volume in n-heptane at 280C temperature and at pH value of 1 on bismuth (III) extraction from 2 Molar HNO3 solution, the optimum removal efficiency percent for TBP solvent was found to be E% = 97% and D2EHPA solvent was found to be E% = 92% respectively. TBP solvent was found to be more efficient for the extraction of Bi (III) from acid leached Bismuth salt sample. Bismuth-xylenol orange spectrophotometry method at 545 nm was used to determine bismuth in all samples while electronic and infrared spectra were also used to clarify the nature of the organic extracts. The information from the data obtained was used in identifying the compounds present in the extracts and their properties.
Keywords: solvent extraction, bismuth (III), TBP, D2EHPA