Adsorptive separation of La, Ce and Pr using microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester

作者：Kondo Kazuo^*; Matsuo Tomohiro; Matsumoto Michiaki

来源：Hydrometallurgy, 2015, 152: 204-213.

DOI：10.1016/j.hydromet.2015.01.004

• Adsorption mechanism
• Separation
• Rare earth metals
• Extractant
• Microcapsule

The adsorption of lanthanum, cerium and praseodymium onto microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) was investigated. Through scanning electron microscopy imaging of the microcapsule-surface and neutralization titration estimation of the amount of EHPNA extractant remaining in the microcapsule, the microencapsulated extractant was characterized. As a result, it was found that the microcapsules with a mean particle diameter of 143 pm contained the extractant of 1.63 x 10(-3) mol/g-microcapsule. The adsorption behavior for each of the metals was measured from the metal adsorption equilibrium and the metal adsorption rates, from which it was estimated that the formation of a metal complex contributes to the overall adsorption rate of the metals. The separation of each of the metals was examined using a column packed with the microcapsules. It was found that the separation of the metals was most enhanced under the conditions of the microcapsule-packed column of 10 cm, the flow rate of 0.002 L/min, and the initial metal feed solution at pH 2.0. The separation of lanthanum, cerium and praseodymium from a La-Ce-Pr mixed solution was then examined in detail, with effective separation of these metals achieved within eight repetitions of the adsorption-desorption step.

• 出版日期2015-2