DE10210467B4 - Process for the treatment of residual municipal waste - Google Patents

Abstract

method for the treatment of residual municipal waste, characterized by that unsorted, untreated, municipal residual waste in a cascade mill with low kinetic crushing energy only to the extent comminuted is that in the fine grain incorporated pollutant particles with light crushable moist, biogenic, organic waste that agglomerate Fine grain fraction <25 mm after the cascade mill separated, with water in proportion Water / solid from 8: 1 to 2: 1 slurried, the sands and slightly soluble chlorides separated by a wet process and the organic phases with the washing waters a sewage treatment plant supplied become.

Description

The The invention relates to a method for the treatment of municipal waste - consisting from a mixture of paper, cardboard, cardboard, plastics, textiles, Metals, biodegradable organic matter, ashes and other waste in particular Pollutants - like Batteries with heavy metals and CI loads, being garbage fractions shredded and selected and separated harmful substance fractions so that further processing or recovery at least a garbage fraction possible becomes.

It There are many methods for treating residual municipal waste. at During combustion, the organic components are largely mineralized. The slags can deposited or restricted as Building materials are used. The procedure requires high expenses for exhaust gas purification and is therefore expensive.

It Methods are known which include mechanical comminution and selection carry out. Thus high-calorific fractions and metal fractions are recycled generated. The recovery of the high calorific fraction takes place in special heating plants or a cement plant or co-incineration in power plants.

A method is known for the thermal disposal of high-calorific fractions from sorted waste and / or residues in fossil-fired power plants, especially coal power plants with wet desulfurization, in which the waste / residues treated and treated and pressed to known pellets / briquettes or a thermal treatment (Homogenization) subjected to the formation of coke-containing material and high-energy gas and optionally controlled depending on the respective necessary gas and coke analyzes and the gas and coke with additives offset, the coal flow in the withdrawal bunker and / or a coal strip and / or a steam generator bunker and / or a coal feeder in front of or in the area of a coal chute and / or a flue gas backwash in a proportion of max. 5%, the allocator coal quantity from preferably 60% firing capacity of the boiler directly abandoned, fed together to a coal mill and burned in the steam generator, wherein the resulting during the thermal treatment high-energy gas supplied partially or completely directly to the steam generator and partially or completely Waiving a separate cleaning is burned ( DE 199 25 011 A ) In DE 199 23 108 A1 In a pretreatment, the entire waste is largely mechanically comminuted and then the entire material is subjected to a wet treatment. In the wet processing, the fractions are separated in the 1st stage, a floating-sink separation and in the 2nd stage in a pulper (pulper) at elevated temperatures. The process is very energy-consuming due to the extensive comminution and the wet-mechanical treatment, in some cases at elevated temperatures. To recover the individual fractions to be recovered, drying is required, which in turn leads to increased energy input.

Farther Be existing pollutants in the mixture by the intensive pre-shredding and distributing the 2-stage wet processing to the entire mixture, which makes further utilization of fractions difficult. It takes place no closer explanation for shredding the waste, no fractionation, no pollutant removal (Cl) and none Separation of certain shares. A feeder of separated components to a sewage treatment plant not done. Likewise, no thermal utilization is provided.

In DE 196 32 731 C2 a process is shown in which household or industrial waste after a 2-stage or multi-stage comminution in finely divided form with an oxygen-containing combustion agent is transferred into a molten slag. The pollutants are incorporated in the slag.

Essential in the process, the energy-consuming fine comminution of Garbage up at least 50% <2 mm.

To Pre-shredding is used for metals and other wastes disrupt the slagging and comminution processes, separated and recycled.

The Incineration is inevitable in the high-temperature process, because the pollutants remained in the garbage are.

The Thermal utilization in a high temperature process is costly. About that addition, the remaining low calorific fraction prepares with biological degradable organics and enriched pollutants problems. Especially the enriched in this fraction high heavy metal contents essentially batteries and the high Cl levels hinder one thermal utilization of this fraction.

to Recycling of this organic fraction has also been biological processes developed in Rotten or in closed Vergehung.

The Expenses for gas purification, however, are significant to the emission limits to comply with and odor nuisance to prevent. In the biologically treated material are the pollutant contents still so high that recycling impossible and impossible a harmless landfill is associated with high expenses.

Also known is a method and an apparatus for the manual sorting of waste, in which at least one sorting station originating from a deposit along a sorting station passing conveyor trash transported selected predetermined components selected by hand and fed to a separate disposal, the Waste is wetted with a liquid before reaching the sorting station in order to bind at least mold fungus spores which have been disposed of in the waste ( DE 199 04 338 A ). Iron and Metallabscheidestationen and a screening drum are arranged downstream of the hand sorting.

The Procedure is time consuming and expensive. A large-scale and effective separation of waste components is hardly possible. Still heard the hand separation of the individual waste components still the most widely used methods in waste processing.

• – Siebdurchganges kleiner ca. 200 mm und
• – Siebüberlaufes größer ca. 200 mm,

wobei der Siebdurchgang kleiner 200 mm in einer Kugelmühle gemischt, zerkleinert und homogenisiert wird, dann einen Magnetscheider zur Abscheidung der Eisenteile durchläuft, danach einer kombinierten Rotte-Luft-Sonnenwärme-Trocknung unterzogen und dann bei einer einstellbaren, im gesamten Verschwelungsreaktor sehr gleichmäßig eingehaltenen Temperatur verschwelt wird, wobei nach der Verschwelung in einer Kondensationsstufe im wesentlichen Wasser, flüssige Kohlenwasserstoffe (Öl) und nicht kondensierbares Schwelgas zur Beheizung des Reaktors verbrannt wird, während der Siebüberlauf größer 200 mm nach einer Eisenabscheidung und ggf. Ausscheidung von Kunststofffolien ggf. zusammen mit anderen Biomasse-Abfällen wie Holz, Rinde oder Stroh ebenfalls in einer Kugelmühle zerkleinert wird, das Zerkleinerungsgut mindestens teilweise zusammen mit dem heißen Schwelkoks der Fraktion kleiner 200 mm gemischt und zu Brennbriketts verpresst wird, während überschüssige Mengen dieses Zerkleinerungsgutes zu Holzwerkstoffplatten vorzugsweise mit hydraulischen Bindemitteln (Gips, Zement,...) verarbeitet werden ( DE 34 02 215 A1 ).Known is a method, a system and facilities for the simultaneous utilization of waste and sewage sludge using a drum screen for preclassifying the waste into two fractions of a

• - Siebdurchganges smaller about 200 mm and
• Sieve overflow greater than 200 mm,

wherein the sieve passage less than 200 mm mixed in a ball mill, crushed and homogenized, then passes through a magnetic separator for separating the iron parts, then subjected to a combined Rotte-Luft-Sonnenwärme drying and then carbonized at an adjustable, maintained throughout the Verschwelungsreaktor very evenly temperature is, after the Verschwelung in a condensation stage essentially water, liquid hydrocarbons (oil) and non-condensable carbonization gas is burned to heat the reactor, while the sieve overflow greater than 200 mm after iron separation and possibly excretion of plastic films, optionally together with other biomass Waste such as wood, bark or straw is also comminuted in a ball mill, the crushed material is at least partially mixed together with the hot coke of fraction smaller than 200 mm and pressed into fuel briquettes, while excess amounts of this Zerk can be processed well to wood-based panels preferably with hydraulic binders (gypsum, cement, ...) ( DE 34 02 215 A1 ).

at This process is a consuming Vorklassierung the garbage and no agglomeration of fine grains in the mill instead. A slurrying of certain proportions of mixture and chlorite separation takes place Not. Likewise, there is no separation of organics, but one Addition of sewage sludge to Garbage and one Mixing with this. The used drying by biological Rotte is slow and not effective for larger amounts of drying material. It also requires a very large amount of space on the Rotteplatz and is without roofing strongly weather dependent.

beträgt, wobei D der Durchmesser der Trommel in Metern ist, die aus der Trommel ausgetragene wässrige Aufschlämmung durch Siebung in eine gröbere und eine feinere Fraktion getrennt wird, die feinere Fraktion klassiert wird, wodurch eine gröbere Fraktion anfällt, die als dekontaminierter Boden abgeführt wird, sowie eine Suspension, aus der nach Entwässerung der Feststoff als Schadstoffkonzentrat abgeführt wird ( DE 38 15 461 C2 ).Also known is a process for the treatment of contaminated soils, which are treated by agitation in aqueous slurry in a drum with the addition of loose chunks of the type of grinding media with a net power consumption of 4 to 16 kW / t throughput and the speed 50 bis 90% of the critical

where D is the diameter of the drum in meters, the aqueous slurry discharged from the drum is separated by screening into a coarser and a finer fraction, the finer fraction is classified, resulting in a coarser fraction being discharged as decontaminated soil, and a suspension from which, after dehydration, the solid is removed as pollutant concentrate ( DE 38 15 461 C2 ).

in this connection it is a wet grinding process, in which loose soil lumps as a grinding media be used at a defined energy. The finely ground Fraction is enriched with pollutants and as an aqueous sludge phase discharged. In an aqueous Phase with excess water no agglomeration of a certain fraction can take place. A Chloride separation also does not occur.

Of the Invention is based on the object in the processing of municipal residual waste to enable a material and biological utilization with special procedural Machining and with low energy consumption se lektive material flows for treatment to win and disturbing Separate pollutants.

The inventive solution is achieved by being unsorted, untreated, communal Residual waste in a cascade mill crushed with low kinetic crushing energy only so far is that in the fine grain incorporated pollutant particles with light agglomerate crushable moist, biogenic, organic waste, the fine grain fraction <25 after the cascade mill separated, with water in proportion Water / solid from 8: 1 to 2: 1 slurried, the sands and slightly soluble chlorides separated by a wet process and the organic phases with the washing waters a sewage treatment plant be supplied.

The elected relationship Water / solid depends on the specific regional composition and the chemistry of the residual waste and the chosen treatment method for the Washings. Become the washing waters a pre-treatment before delivery in a sewage treatment plant undergoes the relationship Water / solid in the direction of 2: 1 set. Be the wash waters directly a sewage treatment plant supplied will the ratio Water / solid in the direction of 8: 1 develop because too high pollutant concentrations lead to technological problems in the sewage treatment plant.

According to the invention the mechanical treatment of municipal residual waste in a cascade mill with a diameter of 5 - 15 m and a specific throughput of 10 - 30 t / h.

The water-rich fine grain fraction can after this gentle comminution (with low kinetic energy) surprisingly easy of the larger organic Fractions - like Wood, paper, plastic and the larger inorganic fractions - like stones and metals - through simple sieving be separated.

The called gentle comminution, fine fraction separation and agglomeration with the organically degradable waste can be carried out in one stage in a cascade mill.

The cascade mill is in principle a ball mill with a larger diameter at the time of rotation the balls are taken up and in a cascade with defined kinetic energy rush to the garbage and crush it so gently.

There everyone unnecessary Crushing process costs energy, this is selective crushing in particular the comminution of organically degradable waste, e.g. Potato peels, lemon peels, diapers and the like - when binding dusty, pollutant-containing material and sand through agglomeration an extremely energy-efficient Process in a rotating grinding unit.

Of course you can this selective milling and agglomeration of fine grain with shredded biodegradable organic material and sand also with other grinding and crushing stages in conjunction with a sieve drum and return of Grist be realized in the grinding or crushing stage. The technical effort is much larger than when grinding in a cascade mill.

The sewage-related low heat fraction 0 - 25 mm, in which the fine-grained Mineral, the CL in the form of table salt and the slightly organic has enriched degradable organics, is added with water to a stirred tank and slurried. The water-solid ratio should be 8: 1 to 2: 1.

In a conventional separation apparatus such as a long sand trap or upstream classifier, the sand (Mi neralik) separated from NaCl loaded water and the organic fraction (sludge). The sands are sent for mineral recycling. The sludge and NaCl-containing organically contaminated waters get into a sludge dewatering after a biological treatment in a normal municipal sewage treatment plant or in an external biological treatment, such as a fermentation plant. The dewatered sludge can be thermally utilized in a sewage sludge co-incineration.

In the mill are grinding balls with diameter ≤ 120 - 125 mm used. In addition to the metal fractions become viscoplastic materials and more surprising Also batteries and other metals as carriers of the main pollutant potential (Heavy metals) after a short residence time with an outlet sieve, mesh size ≥ 50 mm, off the rest Ground material separated.

The Material <50 mm is subjected to at least one screening, the material <25 mm according to the invention with a high readily biodegradable organics and high sand and Glassandanteil is subjected to a further treatment. The named Fraction <25 mm is slurried, the sands and easily soluble Chlorides separated by wet process and recycled. The Washing water is mixed with the fine-grained Organics share a normal sewage treatment plant fed.

Of the Organikteil comes so after the biological treatment in the sewage sludge and is preferably thermally utilized after dehydration.

When Another process variant, the washing water with the organic content a usual one sludge dewatering supplied become. In this, the washing waters are largely separated and a sewage treatment plant fed. The dehydrated Sludge is sent for thermal recycling.

Instead of the treatment in a sewage treatment plant The organic phase and the washing water can also be another biological treatment, such as fermentation.

Based two embodiments the invention will be described in more detail below explained become. Showing:

1 the procedure as a scheme

Embodiment 1

• • heizwertreiche Fraktion
• • mineralisch-organische Fraktion
• • Metalle
• • Schadstoffe

wird zur Zerkleinerung einer Kaskadenmühle zugeführt.Household waste from a mixed populated area consisting of:

• • high calorific fraction
• • mineral-organic fraction
• • metals
• • pollutants

is fed to a cascade mill for comminution.

The Mill has a diameter of 5 - 15 m, preferably 7 m. By choosing the specific throughput from 10 to 30 t / h, preferably 20 t / h, is a selective comminution of household waste reached.

The selective comminution allows the separation of the following fractions:

• viscoplastic Fraction (rubber, shoes, etc.) 3 % • Batteries et al pollutants 1 % • metals (Fe, non-ferrous metals) 5 % • high calorific value Fraction of + 10 mm - 60 mm (foils, paper, cardboard boxes  46 % • low heat Fraction 0 - 10 mm 40 % • Water through evaporation 5 % 100 %

Surprisingly is located in the low-calorific fraction the minced mineral and almost all biologically easily convertible material, such as Fruit and vegetable remains and other leftovers, fecal matter (eg from diapers) u. a ..

It also enriches Join in this faction the Cl from common salt. By the selective Separation of batteries and metals are only low heavy metal contents in the group.

According to the invention Sieve fraction 0 - 25 mm, preferably 0-10 mm, an underutilized sewage treatment plant fed. The task in the sewage treatment plant takes place in the fecal station by rinsing out the transport container with wastewater. In the fecal station is a Sand-Mud separation. The sands are after the sand washing of the Recycling supplied. The mud (the organic fraction) get with the rinse wash water in the usual mechanical-biological treatment and treatment process in a sewage treatment plant.

The clarified Water enters the receiving waters with saline. The organic Fraction from the sieve fraction 0 - 25 mm enters with the sewage sludge in the sludge dewatering. The dehydrated sludge will be preferably a co-incineration in a lignite power plant fed.

Embodiment 2

As in the embodiment 1 will be in a cascade mill selectively produced fractions. The largely of heavy metals liberated sieve fraction 0-25 mm is slurried with wastewater, separated by wet process the sand and the organic fraction (the mud) drained. The washing waters will be with the saline cargo a sewage treatment plant fed. The dehydrated sludges arrive for utilization in a co-incineration of a lignite power plant.

Effect:

at the incineration of household waste fractions to disturb the high mineral content, the high heavy metal content and the high Cl moiety.

at a specific throughput of domestic waste of 10 - 30 t / h in a cascade mill an average of 5 - 15 m can from the resulting low-calorific fine fraction 0 - 25 mm the batteries and other metals are separated and the heavy metal contents kept low. At the same time gather in this faction the crushed by agglomeration of minerals that crushed, readily biodegradable organics and the Cl in the form of table salt The minerals and the high Cl levels can be found in a wet mechanical Sand washing process separated from the organic fraction (sludge) become.

The organic fraction (sludge) can after a drainage Low-emission of a combustion are supplied.

1

cascade mill

2

low calorific fraction

3

calorific fraction

4

slurry

5

Grit separation

6

organic Phase and wash water

7

sludge dewatering

8th

dehydrated mud

9

wash water

Claims (9)

Process for the treatment of residual municipal waste, characterized in that unsorted, untreated, municipal residual waste in a cascade mill crushed with low kinetic crushing energy only so far is that in the fine grain incorporated pollutant particles with light agglomerate crushable moist, biogenic, organic waste, the fine grain fraction <25 mm after the cascade mill separated, with water in proportion Water / solid from 8: 1 to 2: 1 slurried, the sands and slightly soluble chlorides separated by a wet process and the organic phases with the washing waters a sewage treatment plant supplied become. A method according to claim 1, characterized in that as biogenic organic waste fruit and Vegetable dishes, food residues, pulps u. Ä. Be used. Method according to claim 1, characterized in that that a cascade mill equipped with balls with a diameter of 5 - 15 m and a specific throughput of 10 - 30 t / h is used. Method according to claims 1 and 2, characterized by that the organic phases after the sewage treatment with the sewage sludge preferably be supplied to a thermal utilization. Method according to claims 1 to 4, characterized by that after the slurry of the material <25 mm and after the sand removal and chloride separation the organic Phase and the wash water fed to a sludge dewatering, the washings in a sewage treatment plant treated and the dehydrated sludges be supplied to a thermal utilization. Method according to claims 1 to 5, characterized by that the recovered organic sludge according to known treatment methods recycled material. Method according to claims 1 to 6, characterized by that garbage-like Commercial waste and other household waste scraps including bulky waste the treatment according to the invention be subjected. Method according to claims 1 to 7, characterized by that the recovered organic fractions or sludges of a chemical stabilization and immobilization, preferably by Mixture with binders, in particular fly ash from incinerators, and subsequently dumped on landfills or a construction material Recycling supplied become. Method according to claims 1 to 8, characterized by that the organic phase and the washing waters of a fermentation plant supplied become.