Metals recovery from e-scrap using gravity, electrostatic and magnetic separations

Abstract

The purpose of the work was to recover metals from e-scrap, in particular from mainboards of desktop computers, using gravity, electrostatic and magnetic separation. The article describes the method of comminution as well as the yield of size fraction after this process. In addition, the separation of the fraction of 0.32 - 0.56 mm with the use of two systems: I) electrostatic and magnetic separation, and II); gravity and magnetic separation, was presented. The feed to the magnetic separator for both systems was metals (high density products). The yield of fraction 0.32 - 0.56 mm obtained after comminution was 40.7% while the yields of the products obtained from the first system were as follows: in the case of electrostatic separation, 24.9% metals and 75.1% plastics and glass; and for magnetic separation 0.7% of ferromagnetics, 19.0% of diamagnetics and 5.3% of paramagnetics. The yields of the products in the second system were: in the case of gravity separation, fraction with a density ρ > 2.96 g/cc = 33.0% and fraction with a density ρ<2.96 g/cc = 67.0%; and for magnetic separation 0.8% of ferromagnetics, 25.3% of diamagnetics and 6.9% of paramagnetics.