JP7143255B2 - Incineration bottom ash processing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for effectively using incineration bottom ash generated in a municipal waste incinerator or the like as a raw material for cement and a raw material for refining.

Waste such as municipal waste is incinerated, and incineration ash produced by incineration is conventionally landfilled at a landfill disposal site. However, in recent years, in view of the possibility of depletion of landfill disposal sites, attempts have been made to effectively utilize incineration ash. In particular, attempts have been actively made to effectively utilize it as a raw material for cement as a substitute for natural raw materials.

On the other hand, municipal solid waste incineration ash contains repellent components such as chromium (Cr) and heavy metals such as copper (Cu) that are unnecessary for cement production. Especially when the chromium concentration of the incineration bottom ash is high, the use of the incineration bottom ash as a cement raw material has been practically restricted, such as the amount used as a cement raw material must be reduced. Therefore, in order to stably convert incinerated bottom ash into a cement resource, it is preferable to reduce repellent components such as chromium and other unnecessary components by pretreatment.

As a technique for separating heavy metals from municipal solid waste bottom ash, for example, in Patent Document 1, incineration bottom ash is separated into magnetic and non-magnetic substances by magnetic separation, and the non-magnetic substances obtained by separation are treated by a cement burning device. It is described that it is used as a raw material for cement with a reduced chromium content.

Although the above invention is effective, the magnetic substances obtained by magnetically separating the incineration bottom ash, especially the fine particles collected by the drum type or roll type magnetic separator, have ash attached to them. Therefore, there is a problem that the quality of the magnetic substance deteriorates and it is difficult to use the magnetic substance as a raw material for refining.

On the other hand, in Patent Document 2, in order to efficiently recover iron resources that have a low impurity content, a high iron content, and can be recycled, iron scraps are magnetically sorted from the incineration residue and magnetically sorted. A technique for removing impurities adhering to the iron scraps by jetting high-pressure water onto the iron scraps is described.

Further, Patent Document 3 has a vertical cylindrical crushing chamber for crushing objects to be crushed by impact of a multi-stage chain that revolves at high speed, and hot air or air is supplied to the lower part of the crushing chamber as a swirling flow. A technique for dry-cleaning magnetic substances collected by a magnetic separator using a chain-strike crushing dryer is disclosed.

JP 2017-137224 A Japanese Unexamined Patent Application Publication No. 2008-1931 JP 2008-178808 A

However, since the invention described in Patent Document 2 performs wet cleaning using high-pressure water, a water treatment facility is required. In either case, there is a problem of high processing costs because they are subject to heavy wear and require periodic maintenance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to effectively utilize incinerated bottom ash as a raw material for cement and a raw material for refining while keeping treatment costs low.

In order to achieve the above object, the present invention provides an apparatus for treating incineration bottom ash, comprising a magnetic separator for separating incineration bottom ash into magnetic and non-magnetic substances, and magnetic substances discharged from the magnetic separator. a wind sorter for separating into light products and heavy products, the wind sorter being a vertical zigzag wind sorter .

According to the present invention, since the magnetic substances are separated into light products and heavy products by the wind force sorter in the latter stage of the magnetic force sorter, incineration can be performed while keeping the processing cost low without using a wet cleaning machine or a crushing dryer. Bottom ash can be effectively used as a raw material for cement and a raw material for refining.

In the apparatus for treating incinerated bottom ash, a drum-type magnetic force separator having a magnet with a magnetic flux density of 1500 gauss or more and 5000 gauss or less can be used as the magnetic force separator .

In the incineration bottom ash processing apparatus, a dryer for drying the magnetic substances separated by the magnetic separator is provided between the magnetic separator and the wind separator, and the wind separator is the dryer. Separating the dried magnetic substances into light products and heavy products can increase the separation efficiency of the wind separator.

In the incineration bottom ash processing apparatus, a hanging magnetic force sorter having a magnet with a magnetic flux density of 1000 gauss or more and 2000 gauss or less is provided in the preceding stage of the magnetic force sorter, and the magnetic force sorter (hanging magnetic force sorter magnetic force sorter) is configured to separate the non-magnetic substances separated by the hanging magnetic force sorter into magnetic substances and non-magnetic substances, thereby removing relatively large magnetic substances in advance, The presence of relatively large magnetic substances avoids the risk that other non-magnetic substances will be caught in the relatively large magnetic substances in the subsequent magnetic force sorter, making it difficult to collect them on the magnetic substance side. Chromium separation efficiency can be increased.

In the incineration bottom ash processing apparatus, a sieve sorter for separating the non-magnetic substances separated by the hanging magnetic force sorter into a sieved matter and a sieved matter is provided after the hanging magnetic force sorter. Provided, the magnetic force sorter (a magnetic force sorter that is not a hanging magnetic force sorter) separates the under-sieved material separated by the sieve sorter into magnetic substances and non-magnetic substances, so that the magnetic force sorter By recovering relatively large objects in advance in the previous stage, the quality of magnetic substances and the separation efficiency of chromium can be further improved.

As described above, according to the present invention, incineration bottom ash can be effectively used as a raw material for cement and a raw material for refining while keeping treatment costs low.

1 is a block diagram showing an embodiment of an incineration bottom ash processing apparatus according to the present invention; FIG.

An embodiment of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of an incineration bottom ash processing apparatus according to the present invention. This processing apparatus 1 includes a magnetic sorter (hereinafter referred to as "magnetic sorter") 2 for magnetically sorting incineration bottom ash, A sieve separator 3 for sieving non-magnetic substances A separated by the magnetic separator 2, a magnetic separator 4 for magnetically separating the under-sieved substances separated by the sieve separator 3, and a magnetic substance separated by the magnetic separator 4. A dryer 5 for drying B and a wind sorter 6 for separating the dried matter discharged from the dryer 5 into light products and heavy products.

The magnetic separator 2 is provided in order to remove in advance the relatively large magnetic substances A contained in the incineration bottom ash and to effectively perform magnetic force sorting etc. in the latter stage. A suspended magnetic force sorter or the like can be used.

Similar to the magnetic separator 2, the sieve separator 3 is also provided to remove relatively large objects contained in the incineration bottom ash in advance and to effectively perform magnetic separation etc. in the latter stage. can use things.

The magnetic separator 4 is provided to collect the magnetic substance B from the sieved material of the sieve separator 3, and a drum-type magnetic force separator having a magnet with a magnetic flux density of 1500 Gauss or more and 5000 Gauss or less can be used.

The dryer 5 is provided to dry the magnetic substances B separated by the magnetic separator 4 to improve the separation efficiency of the wind separator 6, and a rotary dryer or the like can be used.

The wind sorter 6 is provided to separate the dried product from the dryer 5 into light products and heavy products, and a vertical zigzag wind sorter with high sorting accuracy can be used.

Next, the operation of the processing apparatus 1 having the above configuration will be described with reference to FIG.

Relatively large magnetic substances A contained in the received incineration bottom ash are removed by a magnetic separator 2, non-magnetic substances A separated by the magnetic separator 2 are sieved by a sieve separator 3, and relatively large substances are taken as sieved materials. Remove. The sieved material can be recycled as scrap. The sieved material of the sieve separator 3 is supplied to the magnetic separator 4 and separated into the magnetic substance B and the non-magnetic substance B, and the non-magnetic substance B is used as a raw material for cement.

Furthermore, the magnetic substance B is supplied to the dryer 5 and dried until the moisture content is about 15% or less, and the dried matter from the dryer is supplied to the wind sorter 6, separated into light products and heavy products, and heavy products. is used as raw material for refining.

As described above, according to the present embodiment, the magnetic substance B can be efficiently separated into the raw material for cement and the raw material for refining and effectively utilized without using a wet washing machine or a crusher.

Next, examples of the present invention will be described.

204 kg of municipal solid waste incineration bottom ash (raw ash) was treated with the treatment apparatus 1 described above. In this embodiment, the magnetic separator 2 is a suspended magnetic force separator equipped with a magnet having a magnet density of 1000 Gauss. The sieve separator 3 was set to have a sieve mesh of 35 mm. As the magnetic separator 4, a drum-type magnetic force separator equipped with a magnet having a magnet density of 1500 gauss or the like was used. The wind sorter 6 used a zigzag wind sorter. Table 1 shows the weight ratio, water content, chromium concentration (chemical composition), chromium content and distribution ratio of the incinerated bottom ash and the separated material in each process. The weight percentage indicates the weight percentage of each separated product when the weight of raw ash is 100. The water content was calculated from the amount of decrease when heated at 105° C. until the weight became constant. Chromium concentration was quantified by spectrophotometry or ICP emission spectroscopy on samples pulverized to less than 100 μm after matte melting treatment. The chromium partition ratio was estimated from the weight ratio of each isolate and the chromium concentration analysis results.

From Table 1, the chromium distribution ratio of the non-magnetic substance B used as a raw material for cement is 57.7%, and about half of the chromium contained in the bottom ash can be removed. can be removed.

Further, the magnetic substance B was sorted by wind power by changing the wind speed of the wind sorter 6 . Table 2 shows the weight ratio of magnetized substances and ash (light products) in heavy products by wind sorting by the wind sorter 6 .

From Table 2, it can be seen that the ash adhering to the magnetized particles can be reduced from about 10% to 5% or less by performing the wind separation under the condition of a wind speed of 2 m/s or more. Also, it can be seen that the higher the wind speed, the higher the ash removal rate.

As described above, according to the present embodiment, the non-magnetic substance B having a low chromium content can be effectively used as a raw material for cement, and the chromium content of the clinker can be kept low. In addition, heavy products with a high magnetic substance content can be effectively used as raw materials for refining.

In the above-described embodiment, the magnetic separator 2 and the sieve separator 3 are provided in order to remove relatively large magnetic substances contained in the incinerated bottom ash. can be omitted or only one of them can be used. Further, the types of the magnetic separator 2 and the sieve separator 3, the magnetic flux density of the magnets, and the size of the sieve mesh are not limited to those described above.

Furthermore, the type of the magnetic separator 4 and the magnetic flux density of the magnet are not limited to those described above. In addition, it is preferable to provide the dryer 5 because the separation efficiency of the subsequent wind separator 6 can be increased, but if the water content of the magnetic substance B is already about 15% or less, this can be omitted. .

1 Incineration bottom ash processing device 2 Magnetic separator 3 Sieve separator 4 Magnetic separator 5 Dryer 6 Wind separator

Claims (5)

a magnetic separator that separates incineration bottom ash into magnetized and non-magnetized matter;
An incinerator comprising a wind sorter for separating magnetic substances discharged from the magnetic sorter into light products and heavy products, wherein the wind sorter is a vertical zigzag wind sorter. Ash processing equipment. 2. The bottom ash processing apparatus according to claim 1, wherein the magnetic separator is a drum-type magnetic separator having a magnet with a magnetic flux density of 1500 gauss or more and 5000 gauss or less. Between the magnetic sorter and the wind sorter, a dryer for drying the magnetic substances separated by the magnetic sorter is provided,
3. The apparatus for treating incineration bottom ash according to claim 1 or 2 , wherein the wind separator separates the magnetic substances dried by the dryer into light products and heavy products. A hanging magnetic force sorter having a magnet with a magnetic flux density of 1000 Gauss or more and 2000 Gauss or less is provided in the preceding stage of the magnetic force sorter,
The magnetic sorter (a magnetic sorter that is not a hanging type magnetic sorter) separates the non-magnetic substances separated by the hanging type magnetic force sorter into magnetic substances and non-magnetic substances. Item 1 , 2 or 3 incineration bottom ash processing equipment. A sieve sorter for separating the non-magnetic substances separated by the hanging magnetic force sorter into a sieved product and a sieved product after the hanging magnetic force sorter,
5. According to claim 4 , the magnetic sorter (a magnetic sorter that is not a hanging type magnetic sorter) separates the under-sieves separated by the sieve sorter into magnetic substances and non-magnetic substances. Apparatus for treating incinerator bottom ash as described.

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