LIQUID-LIQUID-EXTRACTION OF ALUMINUM AND GALLIUM WITH 5-SUBSTITUTED 8-HYDROXYQUINOLINES

Various 5-substituted 8-hydroxyquinolines have been synthesized and their extractive properties studied for the separation of Ga and Al in strongly basic medium (3. 5 M NaOH). Among the synthesized molecules, only YEN 10 and YAN 5 extract the gallium ion. The conditional extraction constants are 10**7**. **5 and 10**4, respectively. The constants for aluminum extraction are 10**7**. **7 and 10**3**. **5, respectively. YAN 5 is not selective for Ga versus Al. The rate of phase transfer is first order with respect to Ga and extractant concentrations. The phase transfer constants are 1. 2 multiplied by 10** minus **5 for YAN 5 and 1. 05 multiplied by 10** minus **5 for YEN 10, if the rate is expressed in mol m** minus **2s** minus **1 and the concentrations in mol L** minus **1. These values are lower than for Kelex 100.