SHS Reprocessing of Copper Oxide Waste into Copper Powder

Abstract

Here we report on a single-step, eco-friendly, and facile approach to combustion-assisted reprocessing of oily copper waste into copper powder without preliminary cleaning. Complete reduction of copper from oily copper waste in the combustion wave was reached in the presence of ammonium nitrate and without introducing any reducing agent. The optimal conditions for obtaining >99 % copper powder were reached for green [Cu₂O + m(oil)] + xNt mixtures with m = 7–11 wt % and x = 0.35–0.55, were m stands in wt % and x in mole fractions, both in relation to 1 g-mol of Cu₂O. In scale-up experiments (up to 10 kg of green mixture), the copper powder with oxygen content below 0.5 wt % and free carbon content below 0.25 wt % was successfully produced. Our approach was also successfully applied to combustion-assisted reduction of copper oxide oily waste mixed with nickel oxide to yield composite powders and Cu–Ni alloys.