Air classification of copper granules from recycled electrical cables using a zig-zag separator

Recycling copper electrical power cable scrap presents challenges in achieving high purity of the final product, which is typically in the form of copper granules. To obtain copper granules of the highest possible purity, it is necessary to separate impurities, primarily tin-contaminated copper granules (from tinned elements), from pure copper granules. To investigate the feasibility of separating tin-contaminated (tinned) copper using a zig-zag air classifier, numerical CFD analyses of the process were conducted. These simulations were subsequently validated against experimental studies performed with a laboratory-scale zig-zag air classifier. The conducted research demonstrated that the application of a zig-zag air classifier allows to produce copper granules with a final copper content exceeding 99% Cu. A comparison of the numerical CFD separation process analysis results with the actual experimental data revealed that the model's error is dependent on the morphology of the analyzed granules.