THE SOLVENT EXTRACTION OF NICKEL AND COBALT BYMIXTURES OF CARBOXYLIC ACIDS AND PYRIDINECARBOXYLATE ESTERS

摘要: ABSTRACT A series of fifteen pyridinecarboxylate esters has been synthesized with the structure C5H4N.CO.OR, in which carboxylate group is situated at 2-, 3-, or 4-position on pyridine ring, and R = n-octyl, 2-ethylhexyl, 2-octyl, cyclooctyl, cyclohexyl. The presence these compounds causes substantial synergistic shifts pH50 values for extraction nickel (up to about 2 pH units) cobalt 1.5 by solutions carboxylic acids xylene. extent shift depends nature acid, increases order: n-octanoic < 2-ethylhexanoic Versatic 10 2-bromodecanoic 3,5-diisopropylsalicylic acid (DIPSA). depend a lesser identity ester, except that they are smaller sterically hindered 2-carboxylates than their 3- 4- isomers. Studies using methods continuous variation saturation loading indicate metal complexes e...