Role of ethanol on particle size and morphology during copper oxalate synthesis by Precipitation-Stripping

Abstract

Copper oxalate particles were synthesized from a copper loaded oil phase using the precipitation-stripping (PS) technique with oxalic acid as the stripping and precipitating agent. The copper source was a spent ammoniacal printed circuit board etch solution and LIX 84I was the metal extractant. The role of ethanol in stripping solution on stripping rates, particle morphology and size was investigated. An increase in ethanol concentration enhanced both rate and extent of stripping. PS with aqueous oxalic acid resulted in cushion shaped particles with a wide size distribution which changed to flat discs with an increase in precipitation time. Changes in the polarity, dielectric strength, coupled with significant reduction in the interfacial tension between oil and aqueous phases due to the presence of ethanol in the stripping solution resulted in spherical submicron particles with a narrow size distribution. This investigation paves way for a process to synthesize submicron oxalate particles.