Sodium amide에 의한 methyl propyl ketone과 ethyl formate의 반응으로 킬레이트 추출제의 하나인 β-ketohexanal(이하 KHA)를 합성하고, KHA-클로로포륨에 의한 구리의 추출평형 실험을 통하여 추출특성을 고찰하였다. 흡광도를 측정하여 추출제 KHA의 상간 분배계수와 해리상수, KHA와 구리간 킬레이트의 안정도 상수와 분배계수 및 총괄 추출 평형상수등을 구하고, 추출기구를 구명하였다. 합성한 추출제에 의한 구리의 추출율은 pH 5 이상에서 거의 100%이었고, Cu-Zn-Cd 혼합 금속으로부터 구리의 선택적 추출이 가능하였다. KHA-클로로포름에 의한 구리의 추출 화학종은 CuR₂였으며 추출 평형식은 Cu^(2+) + 2HR → CuR₂+ 2H^+로 표시되었다.

β-ketohexanal as a chelating extractant was synthesized from the reaction of ethyl formate and methyl propyl ketone in the presence of sodium amide, and the equilibrium characteristics in the extraction of copper by β-ketohexanal-chloroform were investigated. The equilibrium constants such as the dissociation constant and the partition coefficient of β-ketohexanal, the stability constant and the partition coefficient of copper chelating complex, and the overall equilibrium constant in the extraction of copper were determined by spectrophotometric measurements, and the mechanism of extraction was proposed. The percent of extracted copper by β-ketohexanalchloroform was near 100%, and the selective extraction of copper from Cu-Zn-Cd mixture was possible. Copper was found to be extracted as CuR₂and the equilibrium reaction was expressed as Cu^(2+) + 2HR ↔ CuR₂+ 2H^+.