Classifications

• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D3/00—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
  • A62D3/30—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents
  • A62D3/33—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents by chemical fixing the harmful substance, e.g. by chelation or complexation
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D2101/00—Harmful chemical substances made harmless, or less harmful, by effecting chemical change
  • A62D2101/08—Toxic combustion residues, e.g. toxic substances contained in fly ash from waste incineration
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D2101/00—Harmful chemical substances made harmless, or less harmful, by effecting chemical change
  • A62D2101/20—Organic substances
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D2101/00—Harmful chemical substances made harmless, or less harmful, by effecting chemical change
  • A62D2101/40—Inorganic substances
  • A62D2101/41—Inorganic fibres, e.g. asbestos
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D2101/00—Harmful chemical substances made harmless, or less harmful, by effecting chemical change
  • A62D2101/40—Inorganic substances
  • A62D2101/43—Inorganic substances containing heavy metals, in the bonded or free state

Definitions

• the invention relates to a method for recycling waste materials by introducing the waste materials together with at least one self-combustible additive containing glass and / or ceramic-forming substances directly into the flame of a burner operated with technical oxygen or with a gas having a higher proportion of oxygen than air, whereby a combustion gas and molten combustion particles are formed, which are subsequently converted into a glass-like and / or basalt-like and / or ceramic-like mass by cooling.
• Landfills are becoming increasingly scarce and environmental regulations are becoming increasingly difficult to dispose of, particularly industrial waste.
• the waste is usually burned or deposited in landfills.
• the valuable materials contained in the waste are irretrievably lost.
• waste incineration is usually followed by flue gas cleaning, in which further solid residues are created. Depending on the type of flue gas cleaning, this includes filter dust, evaporation residues from flue gas washing water or flue gas cleaning residues. Airborne dusts that are retained in filter systems must be disposed of in a manner that is safe from leaching due to their elutability.
• the substance mixtures must consist predominantly of silicon oxide, calcium oxide and aluminum oxide.
• the present invention has for its object to provide a process for the recycling of waste materials with which the waste materials can be converted into an unrestrictedly usable product in an economical manner.
• waste materials are mixed with the self-combustible additive to form a starting material mixture with a mixing ratio of waste materials to additive of 20 to 40 to 80 to 60 percent by mass, and the starting material mixture in the flame at temperatures of 1250 to 1500 ° C and ambient pressure is completely burned.
• the invention is based on the knowledge that a particularly effective conversion of the waste into a basalt-like product, in which the pollutants contained in the waste are safely enclosed, can be achieved if the waste in a certain mixing ratio together with glass-forming substances directly into the flame a burner, in particular a solid burner provided for the combustion of solids, and are completely oxidized at ambient pressure. Since the glass-forming reactions take place directly in the flame, much higher sales are achieved compared to conventionally directly or indirectly heated melting furnaces.
• the technical oxygen is expediently produced in an air separator or a pressure swing adsorption system (PSA system).
• PSA system pressure swing adsorption system
• the combination of technical oxygen with the solid fuel burner also enables the use of low-energy additives for automatic melting in the flame without the addition of additional fuels.
• Residues from waste treatment plants that are contaminated with heavy metals, not leach-resistant, and possibly also with organic contamination, are preferably used as waste materials.
• Such substances should be used as additives that are self-combustible and ensure the desired product properties.
• Substances that contain silicon and aluminum compounds are particularly suitable. Low calorific value waste and / or residues with glass and / or ceramic-forming ash content are particularly advantageous.
• Dry sewage sludge which has to be disposed of anyway, is particularly suitable for this.
• the energy required for melting the waste can only be obtained from the sewage sludge incineration.
• An additional supply of another fuel to the burner is not required energetically after the start-up phase.
• the sewage sludge contains glass-forming substances in sufficient quantities to be able to produce a glass-like product of high quality even with residues from special waste incineration plants that contain little glass-forming substances. Additional emissions are avoided when sewage sludge is used as an additive, since the sewage sludge will have to be incinerated anyway in the future.
• Pyrolysis residues have a calorific value which is too low for conventional combustion, but which is completely sufficient for the melting process according to the invention using the burner operated with technical oxygen or with oxygen-enriched gas.
• pyrolysis residues contain enough glass-forming substances so that an unrestrictedly usable glass-like product can be produced from the waste to be disposed of.
• Lignite ashes are comparable to pyrolysis residues in terms of calorific value and the content of glass-forming substances.
• the rust diarrhea of domestic waste incineration plants or finely comminuted shredder waste can also be used as an additive.
• a further development of the inventive concept provides, in addition to the additive containing glass-forming and / or ceramic-forming substances, to introduce at least one additional additive, in particular asbestos waste, into the flame of the burner, which improves the quality of the glass-like melt.
• the proportion of this additive in the educt mixture should preferably not exceed 10 percent by mass.
• the starting material mixture is expediently completely burned in a rotary kiln in the flame of the burner. This ensures long residence times of the exhaust gases and the resulting melt.
• the rotary kiln is preferably designed with a small cross section and a large axial length so that a sufficient residence time for the waste and the additives is achieved.
• the melted reaction products are deposited on the furnace wall.
• the substances that are not incorporated into the glass-like melt accumulate in the exhaust gas and are drawn off via a flue gas treatment device, which preferably consists essentially of a quench, a hot gas dust separation and a harmful gas separation.
• the resulting melt is preferably discharged in the liquid state through a discharge opening of the rotary kiln.
• a rotary drum kiln or preferably a standing cyclone can also be used.
• the waste and additives are expediently introduced into the flame of the burner by means of a gas.
• Low-nitrogen gases are preferably used, as a result of which excessive nitrogen oxide formation is avoided.
• a fuel gas in particular natural gas, propane or butane, can also be used.
• contaminated gas for example from landfill sites, or polluted exhaust air, for example from tank systems, is used to blow the waste and additives into the flame.
• gases must be disposed of anyway, so that two disposal problems or when using substances to be disposed of as a result of simultaneous treatment with the waste Additives, such as sewage sludge or pyrolysis residues, can even solve three disposal problems at the same time.
• a dispersing and metering device is preferably used to blow the waste and additives into the flame of the burner.
• the method according to the invention is suitable for the treatment of all conceivable waste, in particular industrial waste and especially residues from waste incineration plants.
• the process is particularly suitable for treating residues from hazardous waste incineration plants.
• residues e.g. Filter dusts from the flue gas cleaning of the special waste system have high pollutant concentrations and can only be treated with conventional glazing processes with increased effort.
• the filter dust contains hardly any glass-forming substances. With the method according to the invention, even such residues can be used economically.
• Airborne dusts retained in filter systems of a special waste incineration plant which contain pollutants such as mobilizable heavy metals, easily soluble neutral salts and organic pollutants, such as dioxins, furans fed to a rotary kiln.
• the rotary kiln has a ratio of axial length to diameter of at least 5 (L / D ⁇ 5).
• a solid fuel burner for technical oxygen is used in the rotary kiln.
• an air separator or a PSA system can be provided for the oxygen supply.
• the fly dusts are mixed intensively outside of the rotary kiln with decayed, dry sewage sludge from an industrial sewage treatment plant.
• the resulting mixture of substances is blown into the flame of the solid fuel burner by means of a dispersing device at a flow rate of 9 m / s by means of exhaust air contaminated with pollutants, which accumulates in a pendulum gas device of a nearby tank farm for liquid hazardous waste.
• the feed materials are entrained by the gas flow prevailing in the rotary kiln, react on the path that runs axially to the rotary kiln, and the melted products finally deposit on the furnace wall.
• the melt thus formed is continuously discharged through a discharge opening of the rotary kiln.
• different melting treatment processes can follow (e.g. defined cooling in specified time units and / or mechanical processing).
• the flue gas cleaning essentially consists of a quench, a hot gas dust separator, a gas scrubber, a fixed bed adsorber and a blower.
• the glass-like products resulting from the process can be used in road and path construction, for recultivation purposes, as additives in the concrete industry and the brick-making industry, as inert mining additives or as thermal insulation material.

Applications Claiming Priority (4)

Publications (2)

Family

ID=25938488

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (6)

• 1995
  • 1995-07-05 EP EP95110496A patent/EP0693306B1/fr not_active Expired - Lifetime
  • 1995-07-05 AT AT95110496T patent/ATE171877T1/de not_active IP Right Cessation

Patent Citations (6)

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