Patent ID: 8739708
Filing Date: 2014-06-03
Classification: F23G

Abstract:
1. In a method of processing a solid municipal waste material which includes electronic, electrical, and/or cable waste, in which the electronic, electrical, and/or cable waste is optionally separated from the solid waste material remaining, the improvement which comprises the steps of: (a) shredding the electronic, electrical, and/or cable waste to form shredded electronic, electrical and/or cable waste, crushing the shredded electronic, electrical and/or cable waste, pulverizing the shredded electronic, electrical and/or cable waste down to particles of a particle size of 2 to 5 mm; classifying the particles according to particle size, wherein the particles of a size greater than 5 mm are again pulverized and again subjected to classification, and feeding the particles of a size less than 5 mm to an electromagnetic separator, to divide the particles into two fractions, a ferromagnetic fraction of particles, and a non-ferromagnetic fraction of particles; (b) conveying the non-ferromagnetic fraction of particles to a dryer; drying the non-ferromagnetic fraction of particles in the dryer to remove superficial humidity; warming the dried non-ferromagnetic fraction of particles; and separating the non-ferromagnetic fraction of particles in a corona-electrostatic separator into a fraction of dielectric particles comprising plastic, a fraction of particles which comprises both dielectric particles comprising plastic, and an electrically conductive non-ferromagnetic fraction of metallic particles; (c) mixing the fraction of dielectric particles comprising plastic with air, and pyrolyzing the fraction of dielectric particles comprising plastic to obtain a pyrolysis gas; (d) mixing the fraction of particles comprising both dielectric particles comprising plastic and electrically conductive non-ferromagnetic metallic particles with air, subjecting the fraction of particles comprising both dielectric particles comprising plastic and electrically conductive non-ferromagnetic metallic particles to an air pressure above atmospheric pressure, scrubbing the fraction of particles comprising both dielectric particles comprising plastic and electrically conductive non-ferromagnetic metallic particles to remove dust, and returning the cleaned fraction of particles comprising both cleaned dielectric particles comprising plastic and the electrically conductive non-ferromagnetic metallic particles to the corona-electrostatic separator of step (b) to separate out additional electrically conductive non-ferromagnetic metallic particles and additional dielectric particles comprising plastic; (e) combining the additional electrically conductive, non-ferromagnetic metallic particles obtained according to step (d) with the electrically conductive non-ferromagnetic fraction of particles obtained according to step (b) and optionally separating the combined electrically conductive non-ferromagnetic metallic particles into chemically pure metals including platinum group metals, gold and silver, and recovering the chemically pure metals; and (f) combining the additional dielectric particles comprising plastic obtained according to step (d) with the fraction of dielectric particles comprising plastic obtained according to step (b) to produce additional pyrolysis gas.