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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.

Manufacturing W-Cu composite nanopowders was performed via joint reduction of CuO and WO3 oxides with various ratios (W:Cu = 2:1, 1:1, 1:3, 1:13.5) using combined Mg–C reducer. Combustion synthesis was used to synthesize homogeneous composite powders of W-Cu and hot explosive consolidation (HEC) technique was utilized to fabricate dense compacts from ultrafine structured W-Cu powders. Compact samples obtained from nanometer sized SHS powders demonstrated weak relation between the susceptibility and the applied magnetic field in comparison with the W and Cu containing micrometer grain size of metals. The density, microstructural uniformity and mechanical properties of SHS&HEC prepared samples were also evaluated. Internal friction (Q-1) and Young modulus (E) of fabricated composites studied for all samples indicated that the temperature 1000 °С is optimal for full annealing of microscopic defects of structure and internal stresses. Improved characteristics for Young modulus and internal friction were obtained for the W:Cu = 1:13.5 composite. According to microhardness measurement results, W-Cu nanopowders obtained by SHS method and compacted by HEC technology were characterized by enhanced (up to 85%) microhardness.