Electrostatic separation of aluminium from residue of electric cables recycling process.

Cables and wires have a widespread use due to their application in electric power and data transmission. Since they consist of a conductive core (Cu or Al) and an insulating layer (polymer), they can be brought back to life after disposal through recycling in the form of secondary raw materials such as copper, aluminium and/or polymer. The aim of this paper is to research the possibilities of electrostatic separation use for separating aluminium left in residue fraction after the process of recycling Al waste electric cables, as well as to determine the influence of operating parameters and the optimal separation conditions. Waste fraction characterisation has determined that aluminium is mainly found in small-size particles (<2 mm) with the mass fraction higher than 60%. During the research planning the central composite design was used and three operating variables of an electrostatic separator were tested: roll speed, voltage and separation splitter position. Results have shown that it is possible to obtain a concentrate with the Al mass fraction of 97.86% at 91.20% recovery. It has been shown that the splitter position has the most significant influence on the grade of concentrate and recovery. It has also been shown that the roll speed individually and the interaction of the roll speed and splitter position have a significant influence on the grade of concentrate.