ZnO nanopowder derived from brass ash: Sintering behavior and mechanical properties

The present investigation studied the recycling of zinc from brass ash which is a secondary product produced during the brass smelting process. A retiring cycle was devised to produce high-purity ZnO nanopowders. Recovery of > 90 wt% of the total zinc available was achieved after the calcination of brass ash at 700 °C and a multistage hydrometallurgical treatment at room temperature. ZnO powder produced by the developed method was analyzed by X-ray diffraction, transmission electron scanning microscopy, ICP-AES and BET analysis. The ZnO nanopowder obtained from the brass ash was well dispersed and the size of the individual particles was in the range of 30–50 nm. The purity of the powder was 99.83 wt%, and the surface area was about 30.5 m2/g. A relative density level of about 98.1% was reached with ZnO pellets sintered at 1300 °C.