Classifications

• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
  • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
  • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
  • B09B3/30—Destroying solid waste or transforming solid waste into something useful or harmless involving mechanical treatment
  • B09B3/35—Shredding, crushing or cutting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
  • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
  • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
  • B09B3/50—Destroying solid waste or transforming solid waste into something useful or harmless involving radiation, e.g. electro-magnetic waves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
  • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
  • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
  • B09B3/70—Chemical treatment, e.g. pH adjustment or oxidation
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C1/00—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels
  • C03C1/02—Pretreated ingredients
  • C03C1/024—Chemical treatment of cullet or glass fibres
• • 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
  • 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 present invention relates to a method for disposing of cathode ray tubes, in particular screen tubes, respectively. of glass parts thereof by detaching existing coatings consisting essentially of carbon, polyvinyl acetate, metals, other non-metals and phosphorescent compounds in order to be able to reuse the glass.
• the so-called waste recycling of used cathode ray tubes, in particular screen tubes, involves the removal of coatings which comprise the said tubes.
• coatings which comprise the said tubes.
• These are carbon or graphite coatings, coatings consisting of polyvinyl acetate (PVA), of metals such as, in particular, containing lead, zinc, iron, cadmium and / or aluminum, and also phosphorescent compounds.
• EP-PS 222 949 proposes a method for removing coatings in display tubes. The method provides for screen tubes that have become defective during the manufacturing process to be fed back into the manufacturing process after the coating has been removed.
• EP-PS 222948 proposes the use of nitric acid to separate a glass plate and a glass body in a display tube, the plate and glass in the nitric acid being subjected to an ultrasound excitation in order to separate the two parts.
• the subsequent process for detaching the coatings in the display tube is carried out analogously to the detachment process, proposed in EP-PS 222 949.
• a disadvantage of the detachment process in the two patent documents mentioned is the fact that a strongly alkaline solution, such as, for example, 55% sodium hydroxide solution, must be used, with which the disadvantageous precautionary measures mentioned at the outset when using concentrated hydrofluoric acid can largely be retained.
• this object is achieved by means of a method according to the wording according to claim 1.
• the cathode ray tubes to be disposed of, in particular screen tubes, be used to separate the above mentioned coatings are introduced into a weakly alkaline bath containing, for example, 10% NaOH. It has surprisingly been found that, using surfactants at about 70 ° C. in this treatment bath, the concentration of the sodium hydroxide solution can be kept relatively low, which is at least 55% NaOH compared to the highly concentrated sodium hydroxide solution mentioned above in the prior art. represents a significant advantage.
• the coating is detached from the glass bodies in the weakly alkaline solution in a known manner using ultrasound excitation in the bath.
• the bath After inserting the glass parts resp. Glass body in the 10% sodium hydroxide solution containing the surfactants, the bath is heated to 70 ° C, and the glass parts are treated with ultrasound for about 3 min.
• a nonylphenoloxyethyl / 7-15 EO for example Imbentin N / 52 (from Kolb, Hedingen) or a fatty alcohol oxyethylate, such as, for example, Lutensol AO 30 (from BASF) has proven to be particularly suitable. It is preferred to work with a proportion of 0.1-5% by weight of surfactants in the sodium hydroxide solution for detaching the coatings.
• the bowl is first separated from the cone of the cathode-ray tubes to be disposed of, in particular screen tubes, and then the iron mask and the electrode part are manually removed.
• the glass parts resp. Glass bodies are mechanically broken into pieces of approx. 5-20 cm in size.
• the broken pieces of glass are placed in a bath containing 10% sodium hydroxide and about 2% by weight of a surfactant.
• a surfactant used is, for example, be a 'of the substances listed below:
• the alkaline bath is then heated to approximately 70 ° C., and the glass parts are treated with ultrasound for approximately 3 minutes.
• the transducer responsible for ultrasound excitation can either be part of a wall of the bath, or it can be arranged inside the bath.
• the ultrasound is generated in a known manner, it being possible to work in a frequency range of 20-45 kHz according to the invention.
• the sieve pass essentially consists of the 10% sodium hydroxide solution, containing surfactants, with polyvinyl acetate, carbon and metallic or non-metallic elements detached therein.
• the weakly acidic bath containing the hydrofluoric acid is again placed together with the glass parts on a further sieve, the sieve residue essentially consisting of the cleaned glass parts which still contain residues of the hydrofluoric acid solution.
• the sieve pass, residues of polyvinyl acetate and carbon are contained.
• the glass parts separated from the hydrofluoric acid solution are rinsed with water, whereby residues of the hydrofluoric acid solution are removed. So that the glass parts respectively.
• Vitreous bodies of the cathode ray tubes mentioned in the introduction, in particular display tubes, have been completely cleaned of any coatings and can be recycled.
• the hydrofluoric acid residue which was obtained in stage 5 'Sieben II' as a sieve pass, is filtered again on a finer sieve, whereby residues of polyvinyl acetate and carbon are separated off, which are then deposited.
• the resulting filtrate consists essentially of the 5% hydrofluoric acid solution, which stage 4, for a further acidic treatment I, respectively fed. can be returned.
• the sieve run formed in stage 3 'Sie l 1 r consisting essentially of a 10% sodium hydroxide solution, is filtered, the resulting filter residue consisting essentially of polyvinyl acetate, carbon and metallic elements consists.
• the resulting filtrate consists largely of the 10% sodium hydroxide solution, which level 2, ie the alkaline surfactant treatment of the glass parts, respectively. the vitreous supplied, respectively. can be returned.
• the filter residue formed in stage 8 'Filtration II' consisting of polyvinyl acetate, carbon and metallic and non-metallic elements, is at least partially dissolved in a bath with aqua regia, whereby in particular the metallic and non-metallic elements are dissolved.
• the aqua regia solution is filtered, the filter residue consisting essentially of polyvinyl acetate and carbon, which is deposited.
• the resulting filtrate essentially consists of a solution of metallic and non-metallic elements, which are then separated in solution in a known manner by means of liquid-liquid extraction.
• the metallic elements are finally recovered in a known manner by means of electrolysis.
• FIG. 2 An exemplary embodiment is shown in diagram 2, the process sequence in diagram 2 being analogous to that in diagram 1.
• a 10% sodium hydroxide solution containing a surfactant
• a further 0.5-1 g of PVA and carbon are obtained from the glass cleaned by means of the sodium hydroxide solution by treatment with a 5% hydrofluoric acid. What remains is essentially the original 10 kg of glass, which can now be recycled.
• the process sequence recorded in the flow diagrams shows a possible embodiment variant, for example according to the invention, which can of course be modified, modified or supplemented in any desired manner.
• any other alkali instead of the sodium hydroxide solution
• it being possible, according to the invention to work with a relatively weak alkali, which is made possible by the use of the surfactants according to the invention.
• the use of the surfactants also allows the treatment time of the glass parts or. Glass body can be kept relatively short by means of ultrasound.
• the reprocessing methods of the various treatment solutions and the residues of the coatings obtained can also be varied or varied in any way. be modified. Ultimately, it is a question of cost-effectiveness and the requirements of the legislator to what extent the solutions used are recycled and to what extent the resulting metallic elements have to be recovered.
• Essential to the invention is the fact that for the treatment or. the detachment of the coatings of the display tubes for their disposal an alkaline bath is used, which additionally contains surfactants, the glass parts in the alkaline bath being exposed to ultrasound excitation.

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• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Processing Of Solid Wastes (AREA)
• Paints Or Removers (AREA)

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Publications (1)

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• 1991
  • 1991-08-06 CH CH2325/91A patent/CH680837A5/de not_active IP Right Cessation
• 1992
  • 1992-08-04 EP EP92916575A patent/EP0551481A1/de not_active Withdrawn
  • 1992-08-04 FI FI931527A patent/FI931527A0/fi not_active Application Discontinuation
  • 1992-08-04 AU AU23485/92A patent/AU2348592A/en not_active Abandoned
  • 1992-08-04 WO PCT/CH1992/000160 patent/WO1993002815A1/de not_active Ceased

Non-Patent Citations (1)

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