DE19758658B4 - Secondary building material useful in road and concrete constructions - produced from rubble and old waste incineration slag - Google Patents

Abstract

A method of producing secondary building materials from old waste incineration slags involves mixing of the slags with rubble, magnetic separation of large iron scrap, dry classification at 70 mm sieve size, treatment of the below 70 mm size fraction by further magnetic separation, dry classification at 32 mm with return of oversize material to a slowly operating impact crusher and then to the initial magnetic separation, and delivery of the below 32 mm size dry material onto a 2 mm sieve. The novelty comprises the subsequent steps of (a) spraying water at 5-8 bars from high pressure nozzles onto the sieve; (b) supplying a floating collector material to the below 2 mm size sieved material and separating the material into two particle classes in a two-stage upward flow classifier; and (c) subjecting the 2-32 mm size material to simultaneous attrition and high pressure water sprays in a twin shaft wet attritor. Also claimed is a secondary building material produced by the above method.

Description

Of the The invention relates to a process for the preparation of secondary building materials.

Known is known from DE-AS 1 192 994 a method for processing the residues the burning of garbage for the road and road construction. The combustion residues are passed through a preclassifying sieve including Iron parts crushed in a crusher and the iron parts by means of Magnetic separator sorted out. Mineral components go together with the sieve passage of the preclassifying screen of a reclassification subjected. A disadvantage of this method according to the prior art the low quality the process products, the z. B. very irregular surfaces and still considerable leachability can have.

task The invention is qualitatively improved secondary building materials and to provide a method of producing these secondary building materials, consisting exclusively of consist of mineral components and only minimal leachability demonstrate.

The solution The task is done with secondary building materials and method of making these secondary building materials having the features the claims.

According to the invention Building rubble and aged slag from waste incineration plants are mixed and this mixture is an overband magnet supplied is endured by the coarse Fe scrap. The mixture will subsequently classified dry at a sieve cut of 70 mm. The oversize> 70 mm becomes manual sorted according to unburned components. These become a waste incineration plant transported back to the afterburning. The remaining oversize> 70 mm will be in one United breaker crushed and mixed with rubble as a simple backfill material recycled.

The Material <70 mm becomes after another magnetic separation (drum magnet for sorting of fine Fe scrap and Fe-containing composite material) in one following process step classified to 32 mm dry. The coarse grain> 32 mm comes with a slowly running impact crusher unlocked and the above-mentioned overband magnet fed.

The dry material <32 mm is either stored temporarily and as needed as a product 1 or it is given to a 2 mm sieve. Above that Screen area are in accordance with the invention High-pressure nozzles. The with 5-8 bar from the high pressure nozzles on the screen material aufgedeste water leads to a digestion of cohesive component and leads so to a first deagglomeration of the by the aging process partially baked slag. Find at the same time. on the screen surface, like also at the subsequent process stages, attrition events between the particles of the slag and those of the harder rubble.

The sieve passage <2 mm is then fed according to the invention a Schwimmstoffabscheider. Floating floating substances (ρ ≈ 1 Mg / m ³ ) are predominantly organic fines of the building rubble, such as wood splits or root pieces, which are recycled to the incinerator for post-combustion.

Subsequently, will the material according to the invention split into two classes in a two-stage upflow classifier, namely in a product 2 and a product 3. At the same time takes place in this upstream classifier a re-sorting after floating substances take place, which leads to the waste incineration plant transported back become.

• • Desaglomerierung der durch den Alterungsprozess der Schlacke (z.B. Hydratation der Carbonate) noch verbackenen Schlackepartikel,
• • Zerkleinerung vom zerklüfteten Schlackepartikeln, deren geringere Festigkeit zu einer Beeinträchtigung der späteren Produkteigenschaften führen würde (Verbesserung der Festigkeitseigenschaften der Produkte),
• • Abrundung der Kornoberflächen durch Abreiben von hervorstehenden Graten und Kanten (Verringerung der spezifischen Oberfläche),
• • Nachwäsche der gealterten Schlacke (weitestgehende Verringerung der Eluierbarkeit der Produkte)
• • durch hohe Reibenergie (www.ivaa.de – Doppelwellen-Schwertwäscher, Schauenburg Maschinen- und Anlagen-Bau GmbH) Abrieb auf kleiner 2 mm.

The 2-32 mm sieve is first treated in a 2-wave sword washer and simultaneously supplied with water from high-pressure nozzles. In this process step, an energy-intensive treatment of the particles and in particular of the grain surfaces takes place. This leads to the following effects:

• Deagglomeration of the slag particles still baked by the aging process of the slag (eg hydration of the carbonates),
• • Crushing of fissured slag particles whose lower strength would impair the subsequent product properties (improvement of the strength properties of the products),
• Rounding the grain surfaces by rubbing off protruding ridges and edges (reduction of the specific surface area),
• • After-washing of the aged slag (minimizing the eluability of the products)
• • due to high friction energy (www.ivaa.de - double-shaft sword washer, Schauenburg Maschinen- und Anlagen-Bau GmbH) abrasion to less than 2 mm.

Of others become floats in the sword washer Flooded and discharged separately, which also to the waste incineration plant transported back become.

The the sword washer leaving inert material is used in the two subsequent screening stages in the grain classes 0-2 mm, 2-8 mm (product 4), 16-32 mm (product 5) and 8-16 mm (product 6) classified. The resulting grain class 0-2 mm is the above supplied upstream classifier where it is in the products 2 or 3 received.

The Invention will be illustrated below with reference to embodiments. Show it:

1 FIG. 2 schematically shows the process sequence described above, FIG.

2 FIG. 1 schematically shows the sequence of a method variant 1, FIG.

3 FIG. 2 schematically shows the sequence of a method variant 2, FIG.

3 FIG. 2 schematically shows the sequence of a method variant 3, FIG.

2 In accordance with the basic procedure, recycled rubble and aged domestic waste incineration slag are given in a weight ratio of 50/50 to 75/25.

to Production of grit 0-8, in the following also as Ökosplitt 0-8, the products 4 (material 2-8 mm) and 3 (grain class 0-2 mm) of the basic process in a ratio of 85% by weight / 15% by weight a mixed dump mixed. This creates a chippings 0-8 mm, as a secondary building material in the paving substructure or as concrete aggregate, according to the quality requirements DIN 4226, can be recycled.

3 :

the Basic procedure is recycled rubble and aged municipal solid waste slag in weight ratio 50/50 to 75/25 abandoned.

to Production of base layer material 0-32, also referred to below as Ökotragschichten-mixture 0-32, the products 3 (grain class 0-2 mm), 4 (grain class 2-8 mm), 6 (particle size 8-1.6 mm) and 5 (particle size 16-32 mm). The mixing ratio will be made according to the market requirements and according to the in individually determined by ZTVT-StB 95. By this process variant, a secondary building material for the production of Schottertragschichten generates the quality requirements the ZTVT-StB 95 suffice.

4 :

the Basic procedure is recycled rubble and aged municipal solid waste slag in weight ratio 50/50 to 75/25 abandoned.

The Product 1 (grain class 0-32 mm) of the basic process may be due to its nature and composition in the sense of ZTVT-StB 95 as a secondary building material used for the production of antifreeze coatings (eco-frost protection mixture 0-32) become.

1

Müllheizkraftwerk (MHKW)

2

Rohschlackenzwischenlager

3

rubble delivery

4

aged HMV raw slag

5

interim storage

6

Suspension Magnet

7

gross Ferrous scrap

8th

scrap trade

9

dryer 70 mm

10

Oversize> 70 mm

11

Störstoffsortierung (Unburnt)

12

drum magnet

13

fine Ferrous scrap

14

impact cup slow running

15

dryer 32 mm

16

Giant crushing plant

17

exploitation

18

interim storage 0-32 mm

19

product 1 0-32 mm

20

adding water (5-8 bar)

21

Wet sieve 2 mm

22

floating matter (Density <1 g / cm)

23

Schwimmstoffabscheider

24

2 Waves Sword scrubber

25

upflow

26th

Wet sieve (8 and 2 mm)

27

intermediate 0-2 mm

28

product 4 2-8 mm

29

Wet sieve 16 mm

30

product 5 16-32 mm

Claims (1)

Method of producing chippings 0-8 mm, by processing building rubble and aged slag from waste incineration plants, - whereby the slag rubble is fed so that the weight ratio of rubble and aged slag is 50/50 to 75/25, - this mixture one Overband magnet is fed through the coarse Fe scrap is sustained, - the mixture is then classified dry at a wire cut of 70 mm, - The material <70 mm of the mixture after a further magnetic separation to 32 mm is classified dry, with coarse grain> 32 mm digested with a slow-running impact crusher and the above belt magnet is supplied, - dry material <32 mm a 2 mm sieve, is sprayed with 5-8 bar from high-pressure nozzles onto the material of the screen water, - the screen passage <2 mm is fed to a Schwimmstoffabscheider in which floating substances are separated, - the remaining material is split into two classes in a two-stage Aufstromklassierer, - the sieve passage 2- ≤ 32 mm is evaluated in a 2-wave sword scrubber and at the same time supplied with water from high-pressure nozzles, - further wherein the inert material leaving the sword scrubber in two subsequent screening stages in the grain classes 0-2 mm, 2-8 mm and 8 -16 mm and 16-32 mm classified and the material of grain size 2-8 mm and the material of Grain class 0-2 mm in the weight ratio of 85/15 to 95/05 are mixed to the finished product.