Thermodynamics and Synthesis of Cu Powder from CuO in Waste Tire-Derived Pyrolytic Gas Atmosphere

Abstract

The present study aimed to investigate the reduction behavior of CuO particles under the gaseous atmosphere generated by waste tire pyrolysis. Thermodynamics of the reduction process indicated that CuO could be reduced to the metal via the tire (rubber) pyrolysis route in the temperature range 700-900 K. Oxide reduction experiments were conducted as a function of the reactant mass ratio (m(tire)/m(CuO)) and temperature (600-900 K). The extent of waste pyrolysis increased as the temperature was raised to 900 K. This was accompanied by an increase in the oxide reduction. A significant reduction was attained at m(tire)/m(CuO) = 1.28 when the reactants were heated to 800 K and 900 K. Adding a small amount of waste high-density polyethylene to the tire sufficed for full CuO reduction. CuO reduction reactions and morphological evolution of flower-type CuO particles to relatively equiaxed Cu particles were discussed in terms of experimental and theoretical findings.