Electrochemical recycling of diamond and precious metals from used diamond tools

Abstract

The recycling of used diamond tools, which contain a large amount of unused diamond particles and precious metals, can not only realize the reuse of resources, but also reduce the pressure of environmental protection. In this paper, diamond particles were recovered by acid dissolution of aqua regia, and the current density, complexing agent concentration and pH value of the acid dissolution system were adjusted to recover Cu and Co by electrodeposition. Scanning electron microscope and energy spectrometer were used to study the changes of the composition and morphology of the plated layers, and the effects of the parameters such as current density, complexing agent concentration and pH on the organization and composition of the alloy plated layers were analyzed. The results showed that at the current density of 40 mA/cm², pH 4.5 and complexing agent concentration of 10 g/L, uniformly distributed, dense and moderately thick Cu-Co alloy plating was obtained, and the weight percentages of Cu and Co reached the peak respectively. The Cu and Co in the waste diamond tools can be recovered under this condition with good recovery effect.