| 摘要 |
<p>PURPOSE:To easily extraction separate metal ions, esp. rare earth element ions from an aq. soln. and enahance back extraction efficiency by using a specific acidic phosphoric acid ester as an extracting solvent. CONSTITUTION:An acidic phosphoric acid ester of formula I is contacted as an extracting solvent to an aq. soln. contg. metal ions. In the formula, a=1 or 2, n= an integer of 6-15 and m=n, n-1 or n-2. The ester is produced by reacting the corresponding alcohol with phophorus oxychloride followed by hydrolysis. Because of high viscosity, the ester is diluted to 0.005-0.7 mol/l with an org. solvent such as petroleum fraction or hexane prior to the contact. NH3 or the like is added during extraction so that the pH of the aq. phase after extraction is regulated to 0.5-6. Back extraction is easily carried out and the amt. of mineral acid used is reduced.</p> |
