SiO2 microsphere-assisted reduction of ultrafine CuO powder in a fluidized bed

Abstract

The reduction behaviors of ultrafine CuO powders in a fluidized bed are investigated. The fluidization quality of ultrafine CuO powders is enhanced by adding SiO2 microspheres because of the adhesion of ultrafine CuO powders to SiO2 microspheres. Ultrafine Cu powders are obtained after reduction with the addition of SiO2 microspheres, followed by simple sieving separation. It is found that the as-reduced Cu powders detached from the SiO2 microspheres as the reaction proceeded due to changes in the cohesive forces and the breaking forces. Ultrafine Cu has been successfully achieved via fluidization method with the aid of adhesion and separation of micro/nano particles, which enriched the theories of fluidization process strengthening. This new finding, as a general approach, can be applied to the production of other ultrafine/nano metal powders.