Abstract

Method for recycling electronic waste are included that enable electronic waste separation and recycling to a high level of separation efficiency and end product purity which are improvements over prior methods. In preferred methods, separated electronic waste which has been subjected to magnetic separation to remove ferrous materials and shredded to an average width of less than about 40 mm is provided and then introduced to a first water tank treated so as to have a specific gravity of about 1.20 to about 1.30 and allowing a first portion of the electronic waste to float in the first water tank and a second portion of the electronic waste to sink in the first water tank, and the second portion of the electronic waste is introduced to a water vibrating table, wherein the remaining second portion of the electronic waste leaving the water vibrating table yields at least about 98% sorted recovered materials comprising pure and clean copper, aluminum, wire, circuit boards, stainless steel and mixed plastics. Other preferred embodiments employ use of a horizontal friction dehydrator in secondary separation, use of color sorting of various plastics, employing fresh-water fed vertical dehydrators at end steps of separation and use of a high purity electrostatic separation process for final products.

IPC Classes  ?

• B03B 5/04 - Washing granular, powdered or lumpy materialsWet separating using shaken, pulsated or stirred beds as the principal means of separation on shaking tables
• B03B 5/28 - Washing granular, powdered or lumpy materialsWet separating by sink-float separation
• B03B 5/30 - Washing granular, powdered or lumpy materialsWet separating by sink-float separation using heavy liquids or suspensions
• B03B 9/06 - General arrangement of separating plant, e.g. flow sheets specially adapted for refuse
• B29B 17/02 - Separating plastics from other materials
• B29B 17/04 - Disintegrating plastics

Abstract

Method for recycling electronic waste are included that enable electronic waste separation and recycling to a high level of separation efficiency and end product purity which are improvements over prior methods. In preferred methods, separated electronic waste which has been subjected to magnetic separation to remove ferrous materials and shredded to an average width of less than about 40 mm is provided and then introduced to a first water tank treated so as to have a specific gravity of about 1.20 to about 1.30 and allowing a first portion of the electronic waste to float in the first water tank and a second portion of the electronic waste to sink in the first water tank, and the second portion of the electronic waste is introduced to a water vibrating table, wherein the remaining second portion of the electronic waste leaving the water vibrating table yields at least about 98% sorted recovered materials comprising pure and clean copper, aluminum, wire, circuit boards, stainless steel and mixed plastics. Other preferred embodiments employ use of a horizontal friction dehydrator in secondary separation, use of color sorting of various plastics, employing fresh-water fed vertical dehydrators at end steps of separation and use of a high purity electrostatic separation process for final products.

IPC Classes  ?

• B03B 5/04 - Washing granular, powdered or lumpy materialsWet separating using shaken, pulsated or stirred beds as the principal means of separation on shaking tables
• B03B 5/28 - Washing granular, powdered or lumpy materialsWet separating by sink-float separation
• B03B 5/30 - Washing granular, powdered or lumpy materialsWet separating by sink-float separation using heavy liquids or suspensions
• B03B 9/06 - General arrangement of separating plant, e.g. flow sheets specially adapted for refuse
• B29B 17/02 - Separating plastics from other materials
• B29B 17/04 - Disintegrating plastics