Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
  • D21C5/02—Working-up waste paper
  • D21C5/025—De-inking
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/002—High gradient magnetic separation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/005—Pretreatment specially adapted for magnetic separation
  • B03C1/01—Pretreatment specially adapted for magnetic separation by addition of magnetic adjuvants
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/02—Magnetic separation acting directly on the substance being separated
  • B03C1/04—Magnetic separation acting directly on the substance being separated with the material carriers in the form of trays or with tables
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/02—Magnetic separation acting directly on the substance being separated
  • B03C1/26—Magnetic separation acting directly on the substance being separated with free falling material
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/64—Paper recycling

Definitions

• the present invention concerns improvements in or relating to the dein ing of paper. More particularly, the present invention is concerned with the recovery of paper for recycling purposes, which paper has all traces, or substantially all traces, of ink removed therefrom. More particularly, the invention is concerned with the recycling of high quality white paper utilised in the production of recycled photocopier and laser print paper.
• the present invention is based on the discovery that the ink utilised in laser and xerographic printed papers is comprised of a thermoplastic resin (usually PVC) containing carbon black as pigment and usually ferric oxide to assist in handling the dry ink in the printing device.
• a thermoplastic resin usually PVC
• carbon black as pigment
• ferric oxide to assist in handling the dry ink in the printing device.
• a method of dry separating and/or sorting laser and xerographic printed paper waste containing ink with a magnetic component from other paper waste products containing ink but which does not contain any magnetic material by the use of at least one magnet and by applying an appropriate magnetic force.
• any suitable magnet may be utilised although same should be sufficiently strong in order to separate the paper containing ink with a magnetic component from paper containing ink but without such magnetic component.
• Suitable magnets would be an electromagnet, a permanent magnet or a superconducting magnet.
• a mixture of paper waste products would be allowed to fall substantially vertically past at least one operating magnet and the paper waste containing ink with a magnetic component would be magnetically drawn to one side and collected.
• Any suitable procedure can be adopted in this regard.
• the operating magnet(s) should apply a magnetic force over a large area of the body of paper being treated. Magnetic force is a function of two variables:
• Magnetic flux density is the product of magnetic field strength (or intensity) and permeability of a material.
• the magnetic field strength (intensity) is the magnitude of the field strength vector in a medium (i.e. the magnetic strain produced by neighbouring magnetic elements or current-carrying conductors) .
• this aspect of the present invention would be of benefit to waste paper merchants or in mills which wish to select the particular type of paper for one particular operation in the mill, for example, production of recycled paper suitable for laser or xerographic copier paper.
• the residual paper could then be used for production of a lower grade of recycled paper.
• Suitable magnetic forces are achieved by utilising background magnetic fields in excess of 4000 Gauss (4 tesla) and a field gradient in excess of 1000 Gauss/cm (10 tesla/m) .
• a high gradient magnetic separation device can be envisaged which will not require such high input field strengths. It is the magnetic field gradient that is important to effect the separation. There are several types of high gradient machine designs. These devices have been called "induced pole" devices.
• Suitable devices in this connection are for example:-
• Kolm-Marston separator suitably modified for utilisation with pulping techniques.
• a method of removing magnetic ink from pulp stock formed from xerographic and laser printed paper waste to provide high brightness paper which is spot free comprising feeding such pulped paper waste past at least one magnet for removal of all or substantially all of such magnetic ink.
• all the print is xerographic (there may be some conventional printing on the paper such as headings, logos etc.)
• such method would allow for recycling of the ash present in the paper as well as the fibre, thereby increasing the yield.
• the ink which is normally melted on to the paper has not separated fully from the fibre of the paper after treatment in the pulper, then those fibres with ink still attached thereto would also be removed with such ink by the magnet(s) . Accordingly, the spot removal efficiency is improved since when recycling paper to produce high quality paper one does not require bits of fibre which have ink attached thereto.
• the arrangement of the at least one magnet will be so designed in order to exert a magnetic force comprising a background magnetic field of preferably at least 4000 Gauss and a field gradient preferably of at least 1000 Gauss/cm.
• a plurality of magnets are utilised and the pulp stock is fed along an elongate channel-type container housing.
• the magnetic force is presented to the pulp in such a way that it will allow small magnetic particles to be captured or deflected.
• a method for improving the recyclability of paper waste having ink thereon which does not normally contain a magnetic component, by utilising one or more magnetic carriers in the formulations of the printing ink utilised, to enable same to be removed by use of at least one magnet in accordance with the procedures outlined above.
• the present invention contemplates the use of a magnet of suitable strength to enable a particular type of printed paper to be separated from other types of paper and for ink contained on such paper to be removed during the pulping process, both processes utilising a magnet such as an electromagnet, a permanent magnet or a superconducting magnet. It is also envisaged within the present invention to incorporate one or more magnetic carriers or fillers into other types of inks and adhesive or materials utilised in the paper manufacturing industry, so as to enable such inks and other types of materials to be removed from the paper pulp when recycling is taking place, again by magnetic means.
• any suitable ' magnet can be utilised providing same has sufficient field strength and intensity of field force. It is believed that a power of 10-20 kw would be sufficient to enable magnetic particles and the like to be removed as required.

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Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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• 1993
  • 1993-04-21 GB GB9308250A patent/GB9308250D0/en active Pending
• 1994
  • 1994-04-21 JP JP52293894A patent/JPH08509030A/ja active Pending
  • 1994-04-21 EP EP19940913168 patent/EP0697043A1/en not_active Withdrawn
  • 1994-04-21 RU RU95122629A patent/RU2126860C1/ru active
  • 1994-04-21 WO PCT/GB1994/000842 patent/WO1994024364A1/en not_active Application Discontinuation
  • 1994-04-21 BR BR9406482A patent/BR9406482A/pt not_active Application Discontinuation
  • 1994-04-21 AU AU65420/94A patent/AU6542094A/en not_active Abandoned
  • 1994-04-21 CN CN94191843A patent/CN1122151A/zh active Pending
  • 1994-04-21 CA CA 2161094 patent/CA2161094A1/en not_active Abandoned
  • 1994-04-21 GB GB9407903A patent/GB2277330B/en not_active Expired - Fee Related
• 1995
  • 1995-10-19 FI FI954981A patent/FI954981A0/fi unknown

Non-Patent Citations (1)

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