Metal Enrichment of Finely Ground Electronic Waste using Eddy Current Separation

Abstract

The applicability of Eddy Current Separation (ECS) in the processing of relatively fine (−1.0 mm) electronic waste is investigated. An in-depth understanding of the influences of the operating variables in the ECS is obtained by experimentation and optimization exercise. It is established that a high quality product can be generated with a high recovery of metal values in single stage operation of the ECS even for finely ground electronic waste. A high rotor speed helps in generating a purer product albeit with a lower mass yield. Conveyer belt speed does not have a substantial effect on the quality of the product but the mass yield increases with an increase in the belt speed. The mass yield improves when the feed rate increases but the product grade deteriorates. Material related variables such as particle size and specific gravity play significant roles in the horizontal deflection of the nonferrous metallic particles. It was established that below a size of 0.1 mm effective separation of metals is not possible in the ECS. Although particle shape plays a role, it may not be feasible to achieve separation based on shape in this size range. Mathematical models for the mass yield and product grade were established.