Concerning the selectivity of the experimental device based on eddy currents for the metal waste separation

In this paper, a method for the identification and separation of the ferrous and non ferrous metal waste, as well as of their alloys, is described. For this purpose, the obtained results using an experimental device based on eddy currents are presented. One probe coil having an open magnetic circuit made from Mn Zn ferrite, U type is supplied with a high frequency sinusoidal AC voltage. The probe coil is located on the random nonferrous metal parts from copper and his alloy such as brass, on the aluminum and his alloy duralumin and also on the random ferrous metal parts from steel carbon, ferritic stainless steel and GO silicon steel. The probe coil´s impedance variation to changes in frequency and metal material type were determined by measuring the current when the voltage value was kept constant. The influence of material parameters, such as electrical conductivity for the nonferrous materials, and the magnetic permeability for the ferrous ones, over the depth penetration values of the eddy currents and therefore over the impedance values was highlighted. In contrast to other types of magnetic separators, where the metallic wastes are shredded, the presented method can be applied for the separation of metal scrap with various geometries and sizes.