Abstract:
The study investigated solvent extraction of lanthanum ion by using di(2-ethylhexyl) phosphoric acid (D2EHPA) which is an extractant dissolved in kerosene as membrane solution. The membrane solution was carried out using a microporous hydrophobric hollow fiber membrane extractor. The effect of this process were also studied including the concentration o flanthanum ion in feed solutions in the range of 1 to 1000 ppm, the concentration of D2EHPA in membrane solutions in the range of 0.1 to 1.0 mol/l, the pH of feed solutions within the acidic-pH range, the concentration of sulfuric acid in strip solution in the range of 0.05 to 0.5 mol/l and concentrated lanthanum ion in strip solution. The results of the experiment reveal that the molar flux of lanthanum ion increases in accordance with the concentration of lanthanum ion in feed solution when the concentration of D2EHPA is higher than 0.5 mol/l, but the concentration of lanthanum ion does not affect the molar flux of lanthanum ion when the concentration of D2EHPA is low. In addition, when the concentration of D2EHPA is in the range of 0.1 to 0.5 mol/l, the molar flux increases in accordance with an increase in the concentration of D2EHPA. However, the molar flux is constant when the concentration of D2EHPA is higher than 0.5 mol/l. Furthermore, the percentage of extraction is dependent on the pH of the feed solution, with the maximum value at pH 2.5. It has also been observed that the adjustment of pH by using hydrochloric acid in feed solution give higher molar flux than using buffer solution. Moreover, the extraction is not affected by sulfuric acid with the concentration higher than 0.25 mol/l. Finally, this process can increase the concentration of lanthanum ion in the strip solution by means of diffusing from the feed solution with lower concentration to the higher concentration in strip solution.