EP2818250B1 - Method for the treatment of refuse incineration slag - Google Patents

Description

The invention relates to a method for the treatment of waste incineration slag.

In the treatment and metal recovery of waste incineration slag remaining from the refuse incineration is usually crushed and separated by separation mechanisms. Known deposition mechanisms used industrially for this purpose include magnetic separation, induction deposition, NE deposition, sensor-based systems for deposition, air classification or hand sorting.

Furthermore, methods are known from the prior art, in which using a vibratory settling separator sieved waste incineration slag is separated into a heavy fraction and a light fractions, namely the DE 41 23 277 C1 , the EP 0 913 172 A1 , as well as the DE 410 048 C ,

However, with these currently used techniques, not all the metals in the slag can be economically recovered. Also, if not enough metals are removed from the slag, the processed slag can not be used as a building material due to the high residual metal content. Furthermore, a separation into more than two fractions is not possible in a simple way possible.

It thus results in the task of creating a method for treatment and metal recovery of waste incineration slag, which on the one hand is able to recycle waste incineration slag to a high degree, so that it can be used as a building material, on the other hand allows the residual metals in the slag to separate out a high degree, and allows separation into several fractions.

This object is achieved according to the invention in that waste incineration slag is first comminuted and sieved and then separated by a vibrating settling separator into different fractions of different densities. The separation takes place in a heavy fraction comprising metals, a light fraction comprising mineral and a floating fraction comprising plastics, wood, paper or aerated concrete. The separated heavy cargo is transported directly into a heavy goods storage and the floating goods are transported directly to a floating goods warehouse. The light material is passed through an induction separator for separating metallic materials.

It may be provided according to the invention, before or after the vibratory settling additional deposition mechanisms, in particular the above-mentioned known deposition mechanisms for slag, are used. The use of the vibratory settling separator can be provided, in particular in existing separation processes and separation plants, instead of or in addition to known separation mechanisms. The order of the deposition mechanisms used can also be adapted to the respective task.

The separation of slag constituents according to the invention by a vibratory settling separator makes use of the usually higher specific density of metals compared to mineral constituents of the slag. The result of the process is a metal fraction enriched with mischmetals, as well as a mineral fraction without metals, and a floating fraction comprising plastics, wood, paper or aerated concrete.

The separation takes place in a water bath. As a result, the physical property of solids, according to which they have different sedimentation behavior, in particular different sedimentation rates, at different density in the flowing, pulsating water is utilized. The different settling behavior in a water bath is used to slow the settling of lighter particles by creating an upward flow in the water bath, to suspend and subtract them, while the heavier particles fall against the upward flow and are deposited in such a way.

Due to this separation principle, materials with a density difference from approx. 0.2 kg / dm ³ can be separated from each other. In addition, a separation of floating goods on the surface of the pulsating water bath is possible. It is possible to separate materials with grain size of 1 mm and above.

According to the invention results in the use of such a setting method for the treatment of waste incineration slag from waste incineration plants with recoverable levels of FE and non-ferrous metals, a high efficiency, especially since the density differences between the metals (except aluminum) and the other combustion residues are very pronounced.

The invention relates in addition to the method for the treatment of waste incineration slag on the use of a vibratory settling separator for the separation of metallic residues in the treatment of waste incineration slag.

Advantageous embodiments of the invention will become apparent from the claims, the description and the drawings.

Fig. 1:

ein Ausführungsbeispiel eines erfindungsgemäßen Verfahrens zur Aufbereitung von Müllverbrennungsschlacke;

Fig. 2:

schematische Darstellung eines Schwing-Setzabscheiders zur Verwendung in dem erfindungsgemäßen Verfahren;

Fig. 3a-3b:

schematische Skizzen einer erfindungsgemäßen Vorrichtung zur Aufbereitung von Müllverbrennungsschlacke.

In the following the invention will be explained in more detail with reference to an embodiment. Show it:

Fig. 1:

an embodiment of a method according to the invention for the treatment of waste incineration slag;

Fig. 2:

schematic representation of a vibratory settling separator for use in the inventive method;

3a-3b:

schematic sketches of a device according to the invention for the treatment of waste incineration slag.

Fig. 1 shows the essential steps of an embodiment of the method according to the invention in the form of a flow chart. First, a pre-screening of the slag material and a crushing by breaking, and in consequence a Nasssiebung.

In the Fig. 1 However, separation steps shown are optional and can be changed in the order of the invention or omitted in the process according to the invention.

Thereafter, the material is introduced into a task bunker. A magnetic separator separates the magnetizable materials before the material is introduced into the vibratory jig. This has several dewatering screens in the present embodiment, see description of Fig. 2 ,

While the separated heavy material is transported directly into a heavy goods storage, and the floating material directly into a floating goods storage, n the light goods must be passed through an induction separator for depositing metallic materials.

The remaining water can be separated into coarse sludge and fine sludge and optionally passed through a helical separator or separation hearth, and the filtered-out residual metals are also transported to a heavy goods storage.

Depending on the state of the waste incineration slag used and the treatment target, the aggregates mentioned can be used in addition to the vibratory placement technique.

Fig. 2 shows a vibrating settling separator for use in the method according to the invention. Waste incineration slag is introduced into a water-filled chamber with a sieve, wherein the chamber is pulsatingly pressurized, thereby forming a pulsating water level in the chamber. The introduced slag separates according to their density in components that float at different heights in the chamber in the water bath: Denser components drift down, less dense components drift upwards. The heavy material is withdrawn via a controller.

Fig. 3a - 3b show schematic sketches of a device according to the invention for the treatment of waste incineration slag. The slag is fed by means of a wheel loader via a hopper a task conveyor belt and over this to the upper end of the jig (module 2) in approx. Transported 6.00 m height.

At most, contained in the slag larger magnetic metal parts are removed by an overband magnet, which is located after the hopper on the feed conveyor belt, and laterally dropped into a collection container for recovery.

The jigging machine is on a rd. 2.50 m high steel frame construction constructed (module 1), which houses the control technology and the associated switch boxes.

The jig itself has a height of approx. 3.50 m and consists of a water-filled box in which the water mechanically with approx. Moving 60 strokes per minute vertically up or down, whereby the water filling is placed in a vertically oscillating motion. The water movement can also be done pneumatically.

In the upper third of the box in the water is arranged from the material task to the opposite end, fixed mounted screen covering (0.5mm -2 mm perforation) on which the slag is dropped from the feed conveyor, while spraying simultaneously from above the task with water What ensures a continuous water balance in the box and promotes the hydraulic separation of adhering particles.

Due to the force of the oscillating water bath on the one hand and by gravity on the other hand, the particles move larger than the perforations on the perforated plate to the discharge opening at the opposite end. Particles <1-2 mm, on the other hand, sink through the perforated sheet into funnel-shaped sumps in the moving bottom of the box, from where they are hydraulically fed to the dehydrator (Module 4), due to the suction created during the downward movement of the pulsating water body.

The material flow> 1-2 mm remaining on the perforated plate is separated by the pulsating movement of the water body into particles of larger and smaller density. The lower density particles (light fraction = slag) are enriched by the upward flow of the water bath at the surface of the moving material flow, while higher density particles (heavy fraction = potentially FE and NE metals) in the lower level of the material flow directly above the Concentrate perforated metal.

The heavy fraction is withdrawn via a float-controlled discharge device at the end of the box of the jigging machine, the light fraction via an overlying discharge device. Both material streams, separated in such a way, are fed to the subsequent dewatering device (module 4).

By these physically conditioned and hydraulically-mechanically suitably supported operations, the desired separation of the light fraction from the heavy fraction is effected in a continuous operation.

The water treatment device (module 4) is on a rd. 2.00 m high steel frame support structure (Module 3) built. In module 3, the collecting container for the water arising from the drainage is installed, in which the material flow <0.5 mm - 2 mm is also introduced from the jigging machine.

In module 4, the sludge with a diameter of about 0.1 mm is separated by a hydrocyclone and fed to the light fraction. The excess water from this treatment step is discharged into the reservoir to the water cycle.

The drainage facilities consist of three high-frequency vibrating drainage channels. On one of these grooves, the light fraction is abandoned, and the separated by the vibration of the gutters of the particles of water flows into the arranged below in module 3 collection container.

On the second drainage channel, the heavy fraction is abandoned and also dehydrated as described above. From the dewatering the now reduced to two fractions material flows slide on two arranged downstream discharge belts, one of which throws the FE and NE metal mixture in a collection troughs for further utilization and the other the further demetallized slag on the surface of the waste body. From there, this discharge is picked up by a wheel loader and installed in the landfill.

At most in the abandoned slag still contained unburned residues (eg wood particles, plastic shreds, etc.) = float also remain on the surface of the flow of material in the jig, are separated laterally separated from the other fractions and fed to its own drainage device that works on the same principle, like the ones described above. The discharged livestock is subjected to allowable treatment (e.g., combustion).

Claims (6)

1. Method for treating waste incineration slag, wherein crushed and screened waste incineration slag is separated into fractions of different densities by means of a vibrating settling separator, wherein the separation occurs into a heavy fraction comprising metals, a light fraction comprising minerals, and a floating fraction comprising plastics, wood, paper or gas concrete, and wherein the separation takes place in a liquid, that is in a vertically oscillating water bath, characterized in that the separated heavy material is transported directly into a heavy material store and the floating material is transported directly into a floating material store, and in that the light material is passed through an induction separator for separating metallic materials.
2. Method according to claim 1, characterized in that smaller particles are separated by a perforated sheet with a perforation of 0.5 mm - 2 mm which is vertically inclined towards the material flow in the upper part of the water bath.
3. Method according to claim 1 or 2, characterized in that material floating in the surface area of the water bath is separated separately.
4. Method according to one of claims 1 to 3, characterized in that for separation the waste incineration slag additionally passes through one or more magnetic separators, induction separators and/or spiral separators, which are arranged before or after the vibrating settling separator.
5. Method according to one of claims 1 to 4, characterized in that for dewatering the separated material passes through a drainage channel oscillating at high frequency.
6. Use of a vibrating settling separator for separating components of different densities when treating crushed and screened waste incineration slag, wherein a separation occurs into a heavy fraction comprising metals, a light fraction comprising minerals, and a floating fraction comprising plastics, wood, paper or gas concrete, and wherein the separation takes place in a liquid, that is in a vertically oscillating water bath, characterized in that the separated heavy material is transported directly into a heavy material store and the floating material is transported directly into a floating material store, and in that the light material is passed through an induction separator for separating metallic materials.

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