DE19708458C2 - Process for processing rejects and the use of the product produced by the process - Google Patents

Description

The invention relates to a method for working up Rejects that are particularly important in the processing Cellulose production from recyclable materials len, as well as suggested uses for the after Ver drive manufactured product.

Packaging materials from industry and household who grows the constantly growing scope and fed to a reprocessing. As far as the pre-sorted materials from a single raw material such as glass or old paper are concerned, re-use generally does not pose any difficulties. However, the many mixtures of substances containing metal, plastic and paper are problematic. While the ferrous metal components can be selected relatively easily by magnetic separation, the remaining mixtures of paper, plastics, textiles and metallic residues such as z. B. aluminum foil greater difficulty. In order to deviate from a purely landfill solution, a larger number of processes have already been proposed which attempt to shred the entire mixture and compress it to shaped bodies. For example, DE OS 35 01 139 describes a "process for the production of moldings" by recycling non-reusable plastic waste. These waste materials are mixed with each other in certain proportions and under certain conditions, ground up and then extruded. The following conditions are mentioned:

• - A ratio of thermoplastics to polyethylene 15 ... 25: 85 ... 75.
• - The drying takes place with swirling.
• - The material is at 175 .. "180 ° C in the extruder gives way and through a nozzle with d = 20 mm into one Form pressed.

Reinforcement may take place in the extruder.

This process is characterized by the high poly ethylene limits set narrow limits.

DE OS 21 45 310 proposes plastic and paper shredding waste together. In the further one suitable coating of the particles obtained, preferably wise through cement.

According to DE OS 23 20 989 household waste with supplements conditions are offset after the end of the pouring solidify and be poured into containers. A other form of processing household waste writes DE OS 23 20 995. Here is the to be processed garbage by mixing with a colloid slurry ner plastic mass described. The proportion of the colloid slurry amounts between 10 and 50%. The garbage is in front of the Processing directed by air classifier, discarded lighter parts are first placed in a shredder and then with the remaining parts in a pan restructured by splitting or crushing. The ent standing plastic mass is allowed to solidify into moldings ren.

However, a large part of recyclable materials goes into this lost, since the formation of the shaped bodies is only the education a denser pack on the landfill.

In the currently used system of sorting Waste from what is known as the "dual system" the recycling system of recyclables or paper Paper waste, plastics, textiles and metallic residues such as B. aluminum foil. Of these will be by physically sorting only the rest of the paper recovered fabrics.

In the subsequent wind sifting, the easy separates the other parts while the heavier ones remain. These consist to a large extent of various foils their plastics and are called rejects.

These rejects are considered waste and must be disposed of become. For this, there are currently the disposal channels Thermal recycling, composting and depo on public landfills.

Because of the water content and the large plastic some of the combustion is not easy. When ver The large chlorine content of z. B. foils, PCB and possible dioxin formation is an environmental problem. Au In addition, the high cost of thermal recycling to name the disadvantage.

Only paper residues with a pa are composted share of approx. 80%. The big disadvantage of this procedure rens is that in relation to paper still a bigger one Amount of soil or sewage sludge can be added got to. This results in a very small amount of Paper that is composted. Because of the large proportion of plastics in the rejects, these are not com postable, rotting does not take place.

Since there is also the possibility in many cases the rotten cellulose content by chemical treatment to reduce lung, and on the other hand the plastic parts in unlimited use of the resulting compost Prevention is the scope of this elimination technology very severely limited and also un economically.

The rejects are in most cases for the home landfill declared.

On the one hand, the capacity of the landfills is limited to others will lose valuable economic resources this disposal route cannot be a permanent solution either.

For this purpose it has already been suggested that the rejects in intensive with an olefin mixture, especially waste oil in egg a ratio of rejects to olefin mixture of 5: 1 to 2: 1, preferably 7: 2 to 5: 2 to a homogeneous Mix suspension, this mixture a heat action at temperatures from 200 ° C to 500 ° C, preferred subjected to 250 ° C to 300 ° C and by cooling solidify.

The object of the invention is therefore a simpler Ver drive to reprocessing of rejects, which in the on work in particular on cellulose production from paper contain valuable materials, as well as possible use for the product made by the process strike at which the contained in the rejects Recyclable materials are used for further effective recycling can be.

According to the invention, this object is achieved by that the rejects with nitrogenous waste products and / or a mineral calcium oxide-containing compo not be mixed. The mixing ratio of Rejects with nitrogenous waste products and / or egg a mineral component containing calcium oxide varies from 5: 1 to 2: 1, preferably 7: 2 to 5: 2 be and is both from the intended use purpose, as well as on the plastic content of the rejects pending. It is particularly chlorine-containing Plastics determined. Both calcium oxide serve here as well as the decomposition of the nitrogen-containing samples products released amines and ammonium compounds the binding and thus neutralization of Cl ions.

The mixture of rejects and nitrogenous ones Waste products and / or a mineral calcium oxide term component is heated in, for example, in a  ten mixer heated to temperatures of 100 to 500 ° C. The temperature range to be selected is also from the plastics predominantly present in the rejects, the mixing ratio of both substances and from ver depending on the application.

The processing temperature, like the Mi ration, therefore, if necessary, for the outward journey increase in substances from new sources of income be re-optimized. A temperature range between 250-450 ° C is considered optimal.

The heating can take place both during the homogenization tion process and subsequently made become.

Especially for the production of a product with large According to the present Er proposed the mixture of mineral compo elements with a predominantly granular structure such as Add cement, gravel or grit.

The use of Ab continues to be available here products. As an excellent example, here the one set of power plant ash or glass powder called.

To homogenize the mixture, all types of Suitable grinders. How easy to see are natural Grinders with continuous material throughput pull.

Especially when processing without mineral additives set, but also with fine-grained mineral aggregates Mixing and heating can be open in heated extruders respectively.

Due to the heating, they melt into the rejects contained plastics and envelop the mineral fabric particles. Cellulose particles and other easily decomposable Che substances are at a correspondingly high temperature decomposed with the release of flammable gases.

The possibly generated exhaust gas can Er generation of the heat required for the process become.

With this option, an energy cycle can be achieved will create what results in further cost savings.

After reaching the desired degree of digestion the product cooled in air.

The end product is a dark brown to black hard product, which is used as building material in Can use road construction.

The method is explained below using exemplary embodiments 1 to 3. See also Fig. 1.

example 1

The rejects are roughly crushed and fed via a reject feed 1 to a heated reactor 7 . With an additive feed 2 also arranged on the top of the reactor chamber 7 , defined amounts of additive are admixed. For the feed of the reactor chamber 7 in a targeted mixing ratio, reject supply 1 and additive feed guides 2 are designed as screw conveyors and have control elements that allow the amount of reject material entered and the ratio of the reject material entered to the additive or additives adjust. Depending on the intended use of the end product, the nitrogenous organic waste or calcium oxide-containing minerals are added as an additive in a quantity that allows the chlorine contained in the rejects to be completely bound. By arranged in the reactor chamber 7 of the transport and mixing screw 8 , both components are intimately mixed in the reactor and conveyed to the product chute 14 . In order to improve the mixing, 8 mixing paddles 9 are attached to the transport and mixing screw.

For heating, the jacket of the reactor chamber 7 is enclosed by a heating jacket 10 .

On the top of the reactor chamber 7 three Ver gas discharge lines 4 open.

In order to be able to supply the gases resulting from the thermal decomposition of the reject / aggregate mixture for economic utilization, the process gas discharge line 4 is connected to a gas scrubber 6 with the interposition of a condensate separator 5 . Part of the exiting from the gas scrubber 6 procedural exhaust gas is passed through a heat exchanger 15 surrounding the product chute 14 to the burner 11 through which the heating chamber 7 enclosing Heizman tel 10 is heated.

Due to the exhaust gases burned in the heating jacket 7 , the mixture is in the course of 30 min. continuous run heated to 450 ° C. This creates a black, granular product that can be used as an additive for bituminous road surfaces. The combustion exhaust gases are discharged from the heating jacket through an exhaust connection 3 and can be released into the world after heat recovery.

Example 2

Rejects in the cellulose production from paper containing recyclable materials will arise with nitrogenous ones Waste products and / or a mineral calcium oxide component in a ratio of rejects  Minerals of 5: 2 in a mixer to a homogeneous NEN suspension mixed. This mixture is in one Autoclave with further stirring to a temperature of Heated to 250 ° C. The mixture is zy in an extruder Lindish pellets with a diameter of 20 mm and a length of 30 mm pressed and ver by cooling consolidates.

The exhaust gases that occur during the heating are accumulated catch and mixed with the heating gas for the autoclave.

The pellets are used as heating material for a coal fire recycling plant.

Example 3

A rejects is power plant ash in a ver Ratio of rejects to power plant ash of 1: 2 before Heating to 450 ° C added. The granular product can be used as an aggregate in road construction.

Claims (10)

1. Process for the processing of rejects, which occur in the reprocessing, in particular, of the cellulose recovery from paper-containing materials, characterized in that the rejects are mixed with nitrogen-containing waste products and / or a mineral component containing calcium oxide, with further mixing in a period of 25 to 60 min. subjected to a heat treatment with a final temperature of 200 ° C. to 500 ° C., preferably 300 ° C. to 450 ° C. in a continuous device with increasing temperature and solidified by cooling. 2. Process for reprocessing rejects Claim 1, characterized in that the Er exhaust gases that occur during heating are collected and ner gas washing with alkaline washing medium Can be used as heating gas. 3. Process for reprocessing of rejects Claim 1, characterized in that the Er product generated during the cooling process process to pourable bodies, in particular Bri warp is formed. 4. Process for reprocessing rejects Claim 2 or 3, characterized in that the Mineral fillers in the form of power factory ash, gravel, grit and / or flour from glassy Substances in a ratio of rejects to Fillers from 1: 4 to 3: 2, preferably 1: 2 to Be added 1: 1. 5. Process for reprocessing rejects Claim 1, characterized in that the spit material before heating mineral fillers beige to be mixed. 6. Process for reprocessing rejects Claim 1, characterized in that the spit mineral fillers during heating be added. 7. Use of one according to one of claims 1 to 3 received product as an additive for the Bitu men manufacturing. 8. Use one according to the procedure according to ei nem of claims 1 to 3 product obtained as Joint sealing material in construction and road construction? 9. Use of a method according to the ei nem of claims 1 to 6 product obtained as Aggregate or building material in road construction. 10. Use of a method according to the egg nem of claims 1 to 6 product obtained as Fuel.