Method for recovering metals from electronic waste containing plastics materials

• US 8,800,775 B2
• Filed: 11/13/2009
• Issued: 08/12/2014
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: Igneo IP LLC
• Original Assignee: Terra Nova AS
• Inventors: Thomas, Christian, Vanhelle, Gervais, Menuet, Jol
• Primary Examiner(s): MATTHEWS, TERRELL HOWARD
• Application Number:
  US13/129,150
• Publication Number:
  US 20110220554A1
• Time in Patent Office: 1,733 Days
• Field of Search: 209/3.1, 209/12.1, 209/38, 209/127.2, 209/214, 209/215
• US Class Current: 209/3.1
• CPC Class Codes: B03C 1/30 Combinations with other devices, not otherwise provided for
• CPC Class Codes: B07C 5/344 according to electric or electromagnetic properties sorting according to size measured electrically or electronically B07C5/08; material testing by magnetic means G01N24/00, G01N27/00, by electrical means G01N27/00; electrical measuring devices in general G01R; coin testing G07D5/00
• CPC Class Codes: C22B 7/001 Dry processes
• CPC Class Codes: C22B 7/005 Separation by a physical processing technique only, e.g. by mechanical breaking
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

The invention relates to a method for treating materials containing a mixture of plastic materials and metal materials, said method including: —crushing the material to be treated; pyrolysis of the crushed material; a first magnetic separation performed on the pyrolysed material providing, on the one hand, a ferrous metal fraction and, on the other hand, non-ferrous residue; —a second magnetic separation performed on the non-ferrous residue providing, on the one hand, a non-ferrous metal fraction and, on the other hand, non-magnetic residue. The invention also relates to a facility for implementing said method.

Claims

1. A method for treating materials containing a mixture of plastic and metal materials, said method comprising:

shredding the materials to be processed;

performing pyrolysis of the shredded material;

a first magnetic separation performed on the pyrolyzed materials, providing a ferrous metal fraction and, secondly, non-ferrous residues;

a second magnetic separation performed on the non-ferrous residues, providing, on the one hand, a non-ferrous metal fraction and, on the other hand, non-magnetic residues containing precious metals, and

a step of combustion of the gasses from pyrolysis,

wherein the step of combustion of the gases from pyrolysis is followed by a step of neutralizing the gas with sodium bicarbonate.

2. The method according to claim 1, wherein the material is electronic waste, preferably used electronic circuit boards.

3. The method according to one of claim 1 or 2, wherein the shredding is performed down to a screen passage size D_max not exceeding 50 mm, preferably between 20 and 30 mm.

4. The method according to one of claims 1-3, wherein the pyrolysis is performed at a temperature between 300 and 600°

C. and/or with an air factor between 0.7 and 0.98.

5. The method according to one of claims 1-4, wherein the first magnetic separation is effected by a magnet or electromagnet.

6. The method according to one of claims 1-5, wherein the second magnetic separation is performed using an eddy current separator.

7. The method according to one of claims 1-6, wherein the precious metals contained in the non-magnetic residues include gold, silver, platinum, palladium, rhodium, ruthenium, iridium and/or osmium.

8. The method according to one of claim 1-6 or 7, wherein:

the ferrous metal fraction comprises iron and/or derivatives of iron, and possibly gold and/or

the non-ferrous metal fraction comprises aluminum and/or zinc.

9. The method according to one of claim 1-6 or 7-8, wherein the non-magnetic residues include copper, lead, tin, glass fibers, carbon.

10. The method according to one of claim 1-6 or 7-9, wherein the ferrous metal fraction is combined with non-magnetic residues after the second magnetic separation.

11. The method according to one of claim 1-6 or 7-10, comprising a further stage of processing the non-magnetic residues to recover the copper content in the non-magnetic residue and/or recover precious metals contained in the non-magnetic residue in particular selected from gold, silver, lead, tin, platinum, palladium, rhodium, ruthenium, iridium and/or osmium.

12. A plant for treating a material containing a mixture of plastic and metal materials, comprising successively:

shredding means;

a pyrolysis facility;

a flow line for collecting pyrolysis gasses supplying a combustion chamber;

at the exit from the combustion chamber, a contact chamber fed by a supply of activated carbon and a supply of sodium bicarbonate;

a primary magnetic separator; and

a secondary magnetic separator.

13. The plant according to claim 12, wherein the shredding means are adapted to perform shredding down to a screen passage size D_max not exceeding 50 mm, preferably between 20 and 30 mm.

14. The plant according to one of claim 12 or 13, wherein the primary magnetic separator comprises a magnet or electromagnet placed above a conveyor belt.

15. The plant according to one of claims 12 to 14, wherein the secondary magnetic separator comprises a separator using eddy currents.