Recycling Potential of Waste Di-Isobutyl-Ketone (DIBK) and Recovery of Residual Gold

Abstract

Di-Isobutyl-Ketone (DIBK) has been commonly used in most mining and allied industries to extract gold from aqueous solutions for analytical purposes. In most cases a complexing agent, methyl tricapryl ammonium chloride otherwise called aliquat 336 is added to the DIBK to give a 1% volume by volume solution. The DIBK containing aliquat 336 is then used to extract gold from aqueous solutions for subsequent analysis using Atomic Absorption Spectrophotometry (AAS). After the AAS analysis the DIBK-aliquat solution containing gold is stored as waste since its disposal is often associated with environmental and health problems. This paper investigated the possibility of using distillation to recover gold contained in the waste generated in Ghana as well as the recycling potential of the distillate (regenerated DIBK). It was established that distillation of the waste DIBK yielded about 92% distillate leaving a residue of tar, which contained all the gold in the waste. Thermal oxidation of the residue followed by conventional cyanidation of the resulting ash led to gold recovery of 98.97% and the gold extraction efficiency of the regenerated DIBK compares very well with that of fresh DIBK.