Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B13/00—Obtaining lead
  • C22B13/02—Obtaining lead by dry processes
  • C22B13/025—Recovery from waste materials
• • 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
  • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
  • B03B9/00—General arrangement of separating plant, e.g. flow sheets
  • B03B9/06—General arrangement of separating plant, e.g. flow sheets specially adapted for refuse
  • B03B9/061—General arrangement of separating plant, e.g. flow sheets specially adapted for refuse the refuse being industrial
  • B03B9/062—General arrangement of separating plant, e.g. flow sheets specially adapted for refuse the refuse being industrial the refuse being glass
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B1/00—Preliminary treatment of ores or scrap
  • C22B1/005—Preliminary treatment of scrap
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
  • H01J9/52—Recovery of material from discharge tubes or lamps
• • 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
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling
• • 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
  • Y02W30/52—Mechanical processing of waste for the recovery of materials, e.g. crushing, shredding, separation or disassembly
• • 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
  • Y02W30/60—Glass recycling
• • 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
  • Y02W30/82—Recycling of waste of electrical or electronic equipment [WEEE]

Definitions

• the invention pertains to the technical field of coated glass recycling.
• the current invention relates to a method for removing a coating from glass, and more particularly a method suitable for removing a lead coating from the inside surface of a funnel of a cathode ray tube (CRT).
• CRT cathode ray tube
• CRTs were frequently used, inter alia, in televisions, computer monitors and monitors for specialist applications, for example, in cash dispensers and industrial applications.
• a CRT generates images by the acceleration of electrons towards a fluorescent screen.
• monitors are using more advanced and modern technologies like, among others, liquid crystal displays (LCD), thin film transistor liquid crystal displays (TFT) and organic light emitting diode displays (OLED).
• LCD liquid crystal displays
• TFT thin film transistor liquid crystal displays
• OLED organic light emitting diode displays
• a typical CRT is made from a lead-free screen glass and a funnel glass containing approximately 20% lead, the two being joined by a glass solder containing up to 90% lead.
• the lead acts to improve the optical quality of the glass and to shield the user from X-ray radiation emitted during the electron bombardment of the screen, as disclosed in WO 2014/125266 Al. Whilst this lead glass performs a useful role within a CRT, it poses a substantial environmental risk when the CRT reaches the end of its life and is disposed of. Studies have shown that when CRTs are disposed of in landfill sites, lead can leach from the glass and contaminate ground water. The severity of the environmental risk is such that the disposal of CRTs is regulated by legislation in many countries.
• a procedure for recycling coated glass, for example CRT, where the glass is crushed, separated into different fractions in the form of glass and metal and mixed in a mixing unit for a predetermined period of time during which a liquid circulates through the mixing unit is known from US 5,316,510. According to the procedure, the coating is removed from the glass by the removal effect that is obtained as a result of the tumbling in the mixing unit. The coatings are collected from the circulating liquid by filtering.
• this known method has the disadvantage that it does not allow the release of particles that adhere firmly in the glass or that are in principle enclosed in the glass.
• the aim of the present invention is thus to achieve an improved procedure that makes it possible to remove lead from coated glass with a very high level of purification and thereby also allowing the complete recycling of said glass and lead.
• the described method comprises the grinding of lead coated glass to a finely grained material of a mixture of a glass fraction and a lead fraction, followed by a separation of said lead fraction from said glass fraction based upon a difference in specific weight and / or density.
• a further embodiment of the invention comprises a processing step using an air flow and / or air turbulence, thus enhancing separation efficiency.
• the coated glass is ground to a specific particle size.
• the particle size is 15 to 40 pm, more preferably 20 to 35 pm, more preferably 20 to 30 pm and even more preferably 23 to 27 pm. These particle sizes have shown to yield the most efficient separation and also show the most potential for reuse purposes.
• a further embodiment of the invention is the grinding of the coated glass to be achieved by using a grinding unit comprising a grinding mill.
• this grinding mill comprises steel marbles. Grinding achieved by said mill comprising steel marbles yields the best results in the desired particle size range.
• separation is further enhanced by applying an eddy current before, during or after the separation.
• lead is a non-ferrous metal
• separation of lead and other inert materials, like glass can be improved by applying an eddy current to the mixture, whereby the lead fraction can be more efficiently withheld.
• an apparatus for separating a lead fraction from a lead coated glass whereby the coated glass is crushed and ground to achieve a finely grained material of a mixture of a glass fraction and a lead fraction, comprises a separator unit for separating the lead fraction from the glass fraction based upon a difference in specific weight and /or density.
• said apparatus comprises a separator unit whereby a wind flow and / or wind turbulence is applied.
• said separator unit also comprises a vacuum generator and a non-ferrous separator. The advantage of implementing these elements is a far more efficient separation.
• said apparatus comprises a grinding mill, preferably comprising steel marbles, a conveyer belt for the automated supply of coated glass and two or more storage containers for the storage of said glass fraction and said lead fraction. Implementation of these components has the advantage of fully automating the process executed with said apparatus.
• the present invention concerns a plant for recycling waste CRT material.
• FIG 1 shows a schematic overview of a CRT recycling process, wherein the current invention, comprising a grinding unit and a separation unit, is implemented;
• Figure 2 shows a schematic cross sectional view of the separator unit, in accordance with the invention;
• Figure 3a shows a schematic cross sectional view of an embodiment of the grinding unit, in accordance with the invention;
• FIG. 3b shows a schematic cross sectional view of another embodiment of the grinding unit, in accordance with the invention.
• Figure 4 shows a schematic cross sectional view of an embodiment of the non-ferrous separator along a conveyor belt.
• the present invention concerns a method comprising the grinding of lead coated glass to a finely grained mixture of a lead fraction and a glass fraction, followed by a separation of said lead fraction from said glass fraction based upon a difference in specific weight and / or density.
• the present invention concerns an apparatus suitable for this purpose.
• the present invention concerns a plant for recycling waste CRT material.
• a compartment refers to one or more than one compartment.
• the value to which the modifier "about” refers is itself also specifically disclosed.
• % by weight refers to the relative weight of the respective component based on the overall weight of the formulation.
• coated glass and coated glass waste need to be interpreted as any glass product or glass fraction which comprises one or more non-glass products, in particular heavy metals. Said heavy metals can be present as a coating or layer on the glass product or glass fraction. Even so, heavy metals may be internally present in the glass product or glass fraction.
• the current invention provides a method, comprising the grinding of lead coated glass to a finely grained material of a mixture of a glass fraction and a lead fraction, followed by a separation of the lead fraction from the glass fraction based upon a difference in specific weight and / or density.
• This separation process lays in the fact that it is a dry process, i.e. no leaching agents or other liquids are required, resulting in a simple process with a high yield, which is moreover completely automated and thus very fast and efficient in comparison to other known processes.
• the process provided by the first aspect of the current invention has the advantage of being more environmentally friendly and more safe regarding the health of employees and / or other bystanders in comparison to other known processes.
• a further embodiment of the invention comprises a processing step using an air flow and / or air turbulence, which is applied before, during or after separation. Air speeds need to be carefully regulated in order to obtain a high separation yield. By applying said air flow and / or air turbulence, the separation of the lead fraction from the glass fraction occurs in a faster and more reliable way. More specifically the air flow is able to blow the glass fraction out of the separator unit, whilst the lead fraction can fall through e.g. a mesh-like structure, thus catching the glass and lead fractions in separate containers.
• the particle size of the grinded material is 15 to 40 pm, more preferably 20 to 35 pm, more preferably 20 to 30 pm and even more preferably 23 to 27 pm.
• the finely grained material is fractionated into two or more particle size fractions before the specific weight and / or density separation.
• smaller heavy metal particles e.g. with a particle size of 15 pm
• larger glass particles e.g. with a particle size of e.g. 40 pm.
• particle size fractionation prior to said separation can be of great importance. It is found that fractionation in two or more particle size fractions greatly enhances the efficiency of the specific weight and / or density separation.
• a further embodiment of the present invention uses a four-step particle size fractionation prior to said separation, leading to five fractions.
• the resulting particle size fractions have a considerably narrow range, i.e. of maximally 10 pm, thereby optimizing the specific weight and / or density separation efficiency. This has shown to be particularly useful when the separation of heavy metals, such as lead, and glass are intended.
• the particle size fractionation is obtained by one or more shaker screens.
• the use of shaker screens has the advantage of an easy implementation and a high separation efficiency. Subsequently, each fraction is consecutively passed through the separation unit.
• a further embodiment of the invention uses vacuum conditions to enhance separation.
• the lighter glass fraction is blown and sucked out of the mixture, while the lead fraction can fall through e.g. a mesh-like structure, thus improving the separation speed and efficiency.
• a further embodiment of the invention is the grinding of the coated glass to be achieved by using a grinding unit comprising a grinding mill.
• Said grinding of the coated glass may be achieved by known devices in the prior art.
• said grinding mill may be provided with grinding aids in order to enhance the grinding process.
• grinding aids could be spherical objects such as steel marbles. The inventors found that by grinding the coated glass in said grinding mill, the desired particle size range was consistently achieved, moreover, the presence of these grinding aids showed to enhance the removal of lead coating from the lead coated glass, thus improving the purity of the separated fractions.
• separation is further enhanced by applying an eddy current before, during or after the separation.
• lead is a non-ferrous metal
• separation of lead from other inert materials, like glass can be improved by applying an eddy current to the mixture.
• the lead fraction is temporarily magnetized and repelled by the non-ferrous separator, thus separated from the inert glass fraction, which does not respond to the eddy current.
• an apparatus for separating a lead fraction from a lead coated glass whereby the coated glass is crushed and ground to achieve a finely grained material of a mixture of a glass fraction and a lead fraction, comprises a separator unit for separating the lead fraction from the glass fraction based upon a difference in specific weight and / or density.
• Said apparatus has no need for the addition of liquids, like a leaching agent, which makes it easy to maintain and clean.
• said apparatus comprises a wind flow and / or wind turbulence generator in the separation unit.
• said separator unit also comprises a vacuum generator. Both generators are fully adjustable with the aim of regulating the ideal air flow and vacuum conditions to obtain a high yield separation.
• a further embodiment of the invention comprises a separator unit provided with a non-ferrous separator.
• Said non-ferrous separator is suited for the generation of an eddy current inside the separator, which can temporarily magnetize said lead fraction.
• Said lead fraction is repelled by the non-ferrous separator, thus efficiently directing it to a lead fraction outlet, while the glass fraction is being sucked out of the mixture towards a glass fraction outlet.
• said apparatus comprises a grinding mill, preferably comprising steel marbles, a conveyer belt for the automated supply of coated glass and two or more storage containers for the storage of said glass fraction and said lead fraction.
• a grinding mill preferably comprising steel marbles
• a conveyer belt for the automated supply of coated glass
• two or more storage containers for the storage of said glass fraction and said lead fraction.
• a plant for recycling waste CRT material comprises a crusher unit, a trumble unit, an X-ray separator, a grinding unit, a dedicated separator unit, storage containers, whereby all elements, parts or units are interconnected via conveyor belts and pipes and whereby the separator unit is suited for separation based upon a difference in specific weight and / or density, said separator being provided with a speed adjustable wind flow and / or wind turbulence generator, a vacuum generator and an optional non-ferrous separator.
• FIG. 1 a schematic overview of a CRT recycling process is shown, wherein the current invention, comprising a grinding unit 1 and a separator unit 2 are implemented.
• Crushed CRT glass is fed to the grinding unit by a conveyor belt 10.
• the ground CRT glass leaves the grinding unit via pipe 11, to be consequently fed to the separator unit.
• the separator unit separates the ground CRT glass into two fractions, whereby a glass fraction and a lead fraction are stored in respectively container 3 and 4.
• an X-ray separator 5 with analysis unit 30, a trumble unit 6 and a crusher unit 7 provided with a dust extraction system 29 are present, all being interconnected via conveyor belts 10.
• the X-ray separator, the trumble unit and the crusher unit are not explicitly part of the current invention, they ensure the correct supply of crushed CRT glass to the grinding unit by crushing CRT screens, trumbling out materials other than crushed CRT glass or crushed glass without coating, which could e.g. be metal frames, and by separating crushed glass without coating from crushed CRT glass.
• the non-glass material and the crushed glass without coating are stored in containers 8 and 9 respectively.
• FIG. 2 a schematic cross sectional view of separator unit 2 is shown with more detail.
• the separator unit comprises the following in- and outlets: an inlet for the ground CRT glass 12, an inlet for an air flow and / or air turbulence 16, an outlet for the resulting lead fraction 14 and an outlet for the resulting glass fraction 13.
• the separation takes place on the basis of a difference in specific weight and / or density of both the lead fraction and the glass fraction.
• an air flow and / or air turbulence generator 15, a vacuum generator 18 and a non-ferrous separator unit 19 are implemented in the separator unit.
• the ground CRT glass is supplied to the separator unit via inlet 12 while air is vigorously blown into the separator via inlet 16.
• a vacuum is applied on the outlet 13 by the vacuum generator 18.
• the combination of the air flow and / or air turbulence and the vacuum enhances separation of the lead fraction from the glass fraction by sucking out the lighter glass particles, while the heavier lead particles are able to fall through the outlet 14.
• a separator plate 17 is mounted near the glass / vacuum outlet 13, thereby improving the separation efficiency.
• a non-ferrous separator unit 19 is implemented, which generates an eddy current. Upon application of the eddy current, lead particles are temporarily magnetized and are repelled to the bottom side of the separator unit. As glass particles are not being influenced by this eddy current, they are easily sucked out of the separator via the outlet 13 while lead particles are even more strongly withheld, thus forced to fall through the outlet 14.
• FIG 3a a schematic cross sectional view of grinding unit 1 is shown with more detail.
• the grinding unit comprises the following in- and outlets: an inlet for the crushed CRT glass 20, an air inlet 21, an air outlet 22 and an outlet for the ground CRT glass 23.
• the grinding unit comprises two chambers, a primary chamber 24 and a secondary chamber 25 in which the CRT glass is ground to the desired particle size.
• the primary chamber the CRT glass is ground to an intermediate particle size which can pass the intermediate diaphragm 26. Small enough particles can pass to the secondary chamber where the grinding process continues in the presence of steel marbles.
• the steel marbles ensure both an even smaller resulting particle size, and an efficient removal of lead coating from the lead coated particles.
• FIG. 3b A cross sectional view of another embodiment of this grinding unit is shown in Figure 3b.
• the grinding unit is provided with a larger ground CRT glass outlet 23 and a second outlet diaphragm 28, which allows only the passage of air through outlet 22.
• Figure 4 shows a schematic cross sectional view of an embodiment of the non-ferrous separator 19 along a conveyor belt 10.
• finely ground CRT glass enters the non-ferrous separator via inlet 31.
• glass particles are carried underneath the separator shield 34 by the conveyor belt 10, thus leaving the non-ferrous separator via outlet 33, lead particles are temporarily magnetized and repelled by the non-ferrous separator, thus being carried above the separator shield 34 and leaving the separator via outlet 32 carried by a stream of air.
• a discarded CRT television is delivered to a CRT recycling plant.
• This CRT television is a complex device that has to undergo some manual steps before supplying it to the fully automated CRT recycling process. These manual steps comprise removal of the plastic housing from the device and removal of the main electrical wiring parts.
• the CRT tube still containing some metal and plastic elements that are more difficult to remove, is now supplied to the CRT recycling plant by putting it on the first conveyor belt.
• the CRT tube is carried into a crusher unit where the CRT rube is crushed in smaller parts.
• CRT glass dust which can originate from the crushing step, is extracted by a dust extraction system. The resulting parts of the crushing step are not particularly small, however small enough to distinguish between several main materials.
• a trumble unit seperates the glass and coated glass pieces from other materials like metal and plastic, by allowing the glass and coated glass to fall through the trumble screen, i.e. a mesh or sieve, while withholding the metal and plastic pieces.
• a conveyor belt transports the metal and plastic pieces to a designated storage container while the glass and coated glass is transported via another conveyor belt to an X-ray separator, comprising an analysis unit, provided with an X-ray source and an X-ray camera in order to identify the leaded glass and separate it through an air flow.
• Lead and glass fractions are recirculated through the X-ray separator and its analysis unit until certain purity is achieved.
• Glass that does not contain any lead coating is transported to a designated storage container, while the leaded glass pieces are led to a grinding unit.
• This grinding unit comprises of steel marbles and further downsizes the leaded glass pieces. While downsizing, the steel marbles also have the effect of separating the lead coating from the glass.
• Two diaphragms allow only glass and lead particles of specific sizes to pass through.
• the outlet diaphragm is dimensioned for 25 pm particles or smaller, which is the desired particle size for the efficient separation of lead particles from glass particles.
• the mixture of particles is carried by an air flow tube to a separator unit.
• This separator unit separates the lead fraction from the glass fraction by applying three principles: air turbulence, vacuum suction and non-ferrous separation.
• air turbulence combined with the vacuum suction is able to blow the lighter glass particles out of the separator while the eddy current, generated by the non-ferrous separator, is enabling the temporary magnetization of the lead fraction, thus direction said lead fraction to the bottom side of the separator unit. This way, glass is removed from the separator at the top while lead is removed at the bottom, both fractions carried to a designated storage container.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• Processing Of Solid Wastes (AREA)
• Disintegrating Or Milling (AREA)

Applications Claiming Priority (3)

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• 2018
  • 2018-11-16 EP EP18803977.0A patent/EP3714075A1/de not_active Withdrawn
  • 2018-11-16 WO PCT/EP2018/081507 patent/WO2019101633A1/en unknown

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