DE4306781A1 - Process and installation for the treatment of mixed refuse with a high plastics content - Google Patents

Abstract

In the sorting of mixed refuse with a high plastics content from the areas of industrial refuse, household refuse and building-site refuse, which contains a high proportion of plastics, for example plastic in the form of films, blow mouldings, cartons and foams and at the same time metals, composite materials, foreign materials such as glass, stones, ceramic, wood, leather, textiles, the diversity of the materials and forms of materials present give rise to the difficulty that virtually no single-material end products can be achieved by conventional manual sorting. By the use of various automatically operating treatment stages and the inclusion of special sorting processes for the plastics, the recovery of single-material end products from the material of complex composition fed in is successfully accomplished. <IMAGE>

Description

The invention relates to a method and a plant for the preparation of plastic-rich waste mixtures, preferably packaging waste mixtures from separate collections e.g. B. from the areas of household waste-like Ge advertising waste, household waste, construction site waste, the predominantly plastics z. B. in Form of foils, hollow bodies, cups and foams, besides metals, Composites and also foreign substances such as glass, stones, ceramics, wood, Leather, containing textiles, straightened.

For processing on a technical scale such diverse, valuable materials ent holding mixtures with the aim of recovering the containing Processes are already valuable as secondary raw materials in high purity knows, which are in the correspondingly executed plants essentially limit to you by crushing and sorting classification on you ben to obtain a pre-enrichment of certain substances in sieve fractions in order to to make them more easily accessible for manual sorting and for one after following magnetic separation to reduce the proportion of incorrectly discharged substances. These processing methods are usually carried out dry.

However, methods are also known in which wet preparation is also used steps are carried out.  

For example, in the "Aachen process for household waste management tung "(" Ecological Waste Recycling "by Thilo C. Koch, Jürgen Seeberger, Verlag C. F. Müller Karlsruhe 1984, pages 146 and 147) from household waste in one first dry processing stage fine waste and a large part of the organic Waste, especially paper and light plastics, from the other garbage components separately and in a subsequent wet processing a Rückge Glass and metal are recovered by density sorting.

The hand sorting carried out in many known methods is disadvantageous for plastic recovery, because in addition to the high personnel costs with the no pure end products can be separated during this process step and no high sorting performance can be achieved.

The object of the invention is to provide a method and a system for Processing of waste mixtures of the type mentioned with the greatest possible automatic operation and high throughput for extraction unmixed end products, especially unmixed plastics, as a secondary raw materials.

This task is solved procedurally with the measures of the Kenn Drawing part of claim 1 and plant with the features of Labeling part of claim 7.

Advantageous embodiments of the invention are set out in the dependent claims give.

In the method according to the invention, the garbage mixture to be sorted first freed of impurities on a sorting belt by manual sorting. Interfering substances are understood to mean those substances whose presence increases Malfunctions in operation and damage to the system can result in  for example buckets with solvents or explosives, solid parts made of Me tall (e.g. moped engine) and the, although they may only be minor There are quantities in the garbage mix, expediently before the start the actual sorting should be removed.

The actual processing then begins with a first comminution, the according to the invention is preferably carried out with a rotor shear. Due to the slowly rotating rotors of such a shredding machine the risk of possible occurring explosions is advantageously reduced rigt.

The shredded packaging waste is now separated into one by a wind sifting mainly light goods containing plastics and in a predominantly metallic heavy goods containing separated components.

The metal contained in the heavy cargo is connected in two in a row Steps separated, namely the metallic iron is first by a Magnetic separation separated and then the non-ferrous metal through an eddy current separation. The heavily metal-free heavy afterwards well is now separated by density sorting, which is still difficult well-contained plastic components now received as light goods and a not heavy goods that can be recycled, mainly glass, stones and other Contains residues. The separated light goods become with the light goods the wind sifting combined and cut to about 5 to 10 mm further nert. The shredded light goods are then sorted according to their density. The you Sorting takes place in several stages connected in series different separation liquids, preferably in sorting centrifuges.

Further details, features and advantages of the invention result from the explanations below in schematic drawing figures presented embodiments.  

Fig. 1 shows a flow diagram of a possible plant for performing the processing method according to the invention.

FIG. 2 shows a possible addition or extension of the method according to FIG. 1.

According to FIG. 1, the waste mixture ( 1 ) is first separated in a device ( 10 ) for the subsequent treatment. This Vorrich device ( 10 ) is preferably a bag ripper to expose garbage separately in plastic bags. This is followed by manual sorting ( 11 ) on a sorting belt in order to remove impurities ( 4 ) from the waste mixture ( 1 ).

According to the invention, a screening (not shown in the flow diagram), preferably in a drum sieve, can be carried out between the device ( 10 ) for separating and the manual sorting ( 11 ), in order to remove fine waste from those types of waste which contain fine particles which disrupt the further process route, cut off. The perforated screen should have an opening width of 20 to 80 mm, preferably 40 to 60 mm. The fine waste separated in this way can then, depending on its nature, be reintroduced into the process at a suitable point.

The waste mixture freed from impurities ( 4 ) after manual sorting ( 11 ) is now crushed, for example with a rotor shear ( 12 ). Long parts ( 3 ) that were only partially cut in one dimension by the rotor shears ( 12 ) are sorted out by a long part separator ( 13 ). Depending on the nature of these long parts ( 3 ), it is possible to feed these long parts ( 3 ) via a conveyor ( 8 ) to the manual sorting ( 11 ) or directly via a conveyor ( 7 ) to the rotor shears ( 12 ), or to Remove completely from the further process. A critical upper limit of the length in the long part separation could be, for example, a length of 400 mm.

The pre-shredded waste mixture now passes into a wind sifter ( 14 ), preferably before a riser wind sifter with recirculation mode, in which a separation of the light materials, for example plastics, takes place. The heavy air discharged from the wind sifter ( 14 ) is fed to a magnetic separator ( 15 ), which is preferably formed in two stages with an overband magnetic separator and a belt reel magnetic separator and separates the ferrous metal ( 27 ). By means of a subsequent eddy current separator ( 16 ), preferably devices provided with rotating permanent magnets are used, who then removes the remaining non-magnetic metal components from the heavy material.

The largely metal-free heavy material is now given to a density sorting device ( 17 ) in which a separation according to density takes place, for example at a separation density of 1.5 g / cm ³ . This separation is preferably carried out in an upstream sorter with a vertical channel with laminar inflowing water, which is preferably carried out in a circuit. The light material obtained in this way is fed together with the light material obtained by the air classifier ( 14 ) to a further density sorting, while the residual materials ( 29 ) obtained as heavy material, which are largely free of usable metals and plastics, are discharged from the system.

The light goods of the upstream sorter ( 17 ) and the air classifier ( 14 ) brought together via the conveying devices ( 5 and 6 ) [the light goods of the air classifier discharge must first be separated from the air flow by a suitable device, for example a cyclone; the cyclone is not shown in the flow diagram] are first passed over a further magnetic separator ( 18 ), preferably an overband magnetic separator. This magnetic separation is used to separate metallic Eisentei len ( 31 ), which have reached the light goods as a false discharge and could lead to damage to the subsequent shredding device ( 19 ). The comminution device ( 19 ) is preferably a cutting mill in which the light material to be further sorted is gently comminuted to less than 5 to 10 mm, preferably 6 to 8 mm, without any noticeable fines.

The crushed light material is now dispersed in a stirred tank ( 20 ) with a high energy input in water, whereby a floating material ( 26 ) is obtained, which consists, for example, of wood and foams and is removed from the suspension surface by a corresponding device, for example a pneumatic suction device . Heavy goods still contained in the light goods are drawn off as sink goods at the bottom of the stirred tank ( 20 ) and fed to the residual materials ( 29 ) via a conveyor line ( 32 ).

The remaining light goods are, for example, laterally withdrawn from the stirred tank ( 20 ) and fed to a sorting centrifuge ( 21 ), in which the plastics polyethylene (PE) and polypropylene (PP) are obtained as floating ( 25 ). The sediment separated in this sorting centrifuge ( 21 ) is added to a further dispersion stage ( 22 ) with a separating liquid which has a slightly higher density than water, and the suspension obtained is then fed into another sorting centrifuge ( 23 ) in which the floating material ( 9 ) the plastic poly styrene (PS) is separated.

The remaining sediment is placed in a shaker ( 24 ) on which there is a separation into the plastics ( 30 ), which contain polyvinyl chloride (PVC) and other plastics, and residues ( 2 ), which can contain metals, sand, dirt, etc. he follows.

Depending on the composition of the waste mixtures to be processed, further density separation stages, e.g. B. to separate the floating material ( 25 ) into the single-variety plastics polyethylene (PE) and polypropylene (PP).

When separating densities in sorting centrifuges, it is also possible according to the invention Lich, the sediments obtained during the previous density separation directly, d. H. to open the next sorting centrifuge without previous dispersion give, because in the sorting centrifuges a sufficient energy input immediately bar before separation and thus sufficient dispersion takes place.

The exemplary process shown in the flow diagram is characterized by the lack of treatment stages prone to failure and (with one exception) the lack of cost-intensive manual sorting.

When operating the sorting equipment used wind sifter, upstream Classifiers and sorting centrifuges are the separation media according to the invention Air, water and separating liquids are circulated, so that an emergency agile preparation of these separation media is only required to a small extent is.

With certain types of waste that contain composites in the form of beverage cartons, it is possible because of the inner foil made of aluminum present in most beverage cartons to separate the cartons with the help of eddy current separation. Since, for reasons of further recycling - the paper fibers in the cartons should not be damaged by shredding, and in wet processing, should not be contaminated by dirty water - it may be required to separate the cartons from the delivered waste mixture as uncrushed as possible Cases, as shown for example in FIG. 2, the processing plant according to FIG. 1 are expanded or supplemented by further plant parts.

Exactly as in the process diagram according to FIG. 1, there is first a separation, preferably in the form of a sack ripper ( 10 ), in order to expose garbage packed in sacks. This is followed by sieving ( 32 ), preferably using a drum sieve, with a grain size of 120 to 180 mm, preferably at 140 to 160 mm, with the aim of enriching the beverage cartons in the sieve underflow. In addition to these beverage cartons, other components such as plastics, tin cans, aluminum packaging and other substances are naturally also discharged as a sieve underflow.

While the sieve overflow is now being conveyed to the already described interfering substance selection ( 11 ) and further processed according to the method of FIG. 1, the tinplate cans and other iron parts ( 36 ) are separated from the sieve underflow by a subsequent magnetic separation ( 33 ), preferably an overband magnetic separator . The non-magnetic material is now separated into a non-metal material and a metal-containing material by an eddy current separator ( 34 ), preferably an eddy current separator with rotating permanent magnets. The non-metal material is conveyed to size reduction ( 12 ) and further processed according to the method of FIG. 1, while the metal-containing material now gets into a wind sifter ( 35 ), preferably a riser sifter, from which the beverage cartons as light material ( 37 ) in highly enriched form and non-ferrous metals are discharged as heavy goods ( 38 ).

Claims (9)

1. Process for the preparation of plastic-rich waste mixtures, preferably before packaging waste mixtures from separate collections z. B. from the fields of household waste-like commercial waste, household waste, construction waste, the predominantly plastics z. B. in the form of foils, Hohlkör cores, cups, foams, in addition to metals, composites and in addition to the foreign matter, such as glass, stones, ceramics, wood, leather, textiles, characterized by the following interlinked process steps:

• a) Selection of impurities by hand sorting;
• b) size reduction, preferably with slow-speed size reduction machines, for example rotor shears ( 12 );
• c) air classification of the comminution products from b);
• d) metal separation from the heavy material of the sorting stage from c) by magnetic separation and / or eddy current separation;
• e) density sorting of the non-metals from the sorting stage d);
• f) comminution of the light materials from the sorting stages c) and e);
• g) Dispersion of the shredded light materials from f) and sorting according to density.

2. The method according to claim 1, characterized in that before the Pre-shredding is carried out, preferably in Expose prepackaged rubbish to plastic bags. 3. The method according to claim 2, characterized in that between the Pre-crushing and screening of contaminants, preferably a screening with a drum screen. 4. The method according to claim 3, characterized in that the sieve sub run one by one to separate the uncrushed beverage cartons Magnetic separation, eddy current separation and wind sifting is subjected. 5. The method according to claim 1, 2, 3 or 4, characterized in that between the process stages b) and c) a separation of longer stö render parts by a long part separator ( 13 ). 6. The method according to claim 1, 2, 3, 4 or 5, characterized in that the density sorting according to e) preferably a wet working upstream sorting is. 7. The method according to one or more of the preceding claims, characterized in that the density sorting according to g) in several stages connected in series with different separating liquid densities, preferably in sorting centrifuges ( 21 , 23 ). 8. Plant for carrying out the method according to one or more of the preceding claims with a plurality of comminution and sorting stages, characterized by the system parts which are listed below and are connected by means of transport means, with

• a) a sorting belt ( 11 ) for the selection of impurities, the end of which is connected to the feed device of a first size reduction stage ( 12 );
• b) a first size reduction stage ( 12 ), preferably a rotor shear, the discharge of which is connected to the feeding device of a wind sifter ( 14 );
• c) a wind sifter ( 14 ), the heavy material discharge with the feed device of a magnetic separator ( 15 ) and the light discharge with the feed device of a second size reduction stage ( 19 );
• d) a magnetic separator ( 15 ), the non-magnetic material discharge of which is connected to the feed device of an eddy current separator ( 16 ) and the discharge of the eddy current separator ( 16 ) for the non-metal material is connected to the feed device of a first wet density sorter;
• e) a first wet density sorter ( 17 ), preferably an upstream sorter, with a discharge for the float, which is connected to the feeding device of the second crushing stage ( 19 );
• f) a second size reduction stage ( 19 ), preferably a cutting mill, the discharge of which is connected to the feed device of a dispersion stage ( 20 ) of a second wet density sorter ( 21 );
• g) a second wet density sorter ( 21 ), preferably a sorting centrifuge, the sink material discharge with the feed device of a further third density sorter ( 23 ), and the sink material discharge in turn connected with the feed device of a further density sorter ( 24 ) etc., the last density sorter preferably is a shock source.

9. Plant according to claim 8, characterized in that the sorting belt ( 11 ) upstream pre-shredding stage ( 10 ) with a Siebanla ge ( 32 ), preferably a drum screen, the Siebun terlaufaustrag with a magnetic separator ( 33 ) and the Siebüberlaufaus carry with a sorting belt ( 11 ), and wherein the discharge of the magnetic separator ( 33 ) for the non-magnetic material with an eddy current separator ( 34 ) and the discharge for the metal material is connected to an air separator ( 35 ).