JPH11246244A - Apparatus for recovering slag from waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for recovering slag from waste capable of inexpensively producing firm aggregate and effectively utilizing the combustion heat of the waste as clean gas. SOLUTION: This slag recovering apparatus having forming devices 1, 11 for molten slag for subjecting the waste (d) to a high-temp. treatment, a water granulating device 7 for water cooling the resulted molten slag a to form water granulated slag (b) and a rotary kiln 16 for crystallizing the water granulated slag (b) is provided with a slag crushing device 14 before or behind the rotary kiln 16. The rotary kiln 16 which recovers the heat generated by the high-temp. treatment of the waste by a ceramic heat exchanger 18 and uses the heat as a heat source is preferable. At this time, a fan 15 for feeding the hot air as the heat source is preferably installed upstream of the rotary kiln 16. A dust collector to be exclusively used for removing the dust component in exhaust gases may be installed to the rotary kiln 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recovering slag from waste, and more particularly, to a method for treating molten slag obtained by subjecting waste to high temperature treatment, more preferably gasification and melting treatment, to obtain water granulated slag. The present invention relates to a recovered slag collecting device.

[0002]

2. Description of the Related Art Conventionally, recycling of molten slag has been introduced in the literature, and these techniques can be applied not only to sewage sludge but also to molten slag of ash from municipal solid waste.
In the following, conventional techniques are described based on known documents. It is known that the strength and shape of molten slag vary depending on the cooling method. Table 1 shows the cooling method and the characteristics of the molten slag.

[0003]

[Table 1]

[0004] When the melt taken out of the melting furnace is rapidly cooled with water, it becomes fine granulated slag, and when left in the air, it becomes a massive air-cooled slag. The slag produced by these methods becomes vitreous (amorphous), and so large strength cannot be expected. It is said that the slag strength is increased by crystallization, but the cooling rate is important for the cold preservation method, and the temperature and the holding time are important for the reheating method as the factors governing the crystallization. The generation of crystallized slag by the cold insulation method
It is gradually cooled as compared with the water-cooled type or the air-cooled type, but the cooling rate required to change from glassy to crystalline (for example, 3 ° C.)
/ Min or less). It has been reported that the generation of crystallized slag by the reheating method may be performed by raising the temperature of the slag and keeping it at 1000 to 1200 ° C. (set between the melting point and the glass transition temperature) lower than the melting temperature for 30 minutes or more. Among them, the granulated slag is easy to maintain because the structure of the device is simpler than others. Another characteristic is that the furnace has excellent sealing properties.

FIG. 6 shows a conventional granulated slag cooling and solidifying apparatus. In FIG. 6, 1 is a melting furnace, 2 is a granulated trough, 7
Denotes a granulated water tank, 8 denotes a slag carry-out conveyor, 9 denotes a slag pit, 10 denotes a circulating water pump, a denotes molten slag, b denotes granulated slag, and c denotes water. Although the molten slag a can be dropped directly from the furnace 1 to the granulated water tank 7, the internal pressure rises due to the sudden generation of steam, and there is a danger of explosion. Therefore, there is a method in which a granulation nozzle is provided right beside the granulation trough 2 which falls vertically from the melting furnace 1 into the granulation water tank 7 to mitigate the generation of steam. The conventional method of producing granulated slag b is mainly a method of reducing the diameter of the molten slag a by simply bringing the molten slag a directly into contact with water and rapidly cooling it.

On the other hand, since the safety of slag has been confirmed, its use is being studied mainly for construction materials such as concrete aggregates, roadbed materials and others. However, slag is usually required due to transport requirements after discharge.
Generally, it is granulated and collected as granules of about several mm. Granulated slag, although having the above-mentioned features, contains massive ones, or has a different particle size, or produces needle-like projections, and it is difficult to say that the handling as a material is good, It requires crushing, is vitreous and has low strength, and its use is limited. In this way, when the molten slag is granulated, continuous operation, a low-cost, energy-saving slag collection device is completed, but as described above, the granulated slag is hard to handle as a material, and reuse is difficult. For further promotion, it was necessary to add value to the granulated slag. The rotary kiln can continuously reheat and crystallize the granulated slag, and by rotating the furnace, the slag has fluidity and moves the slag little by little in the kiln. Therefore, it can be said that it is an optimal heat treatment furnace for producing crystallized slag with good heat transfer and high strength.

As for a method of effectively utilizing the heat generated by combustion as a heat source of a rotary kiln, a method using waste combustion gas (Japanese Patent Application Nos. 9-144578 and 9-227079) was filed first. However, in this case, depending on the type of heavy metal (including its compound) vaporized in the exhaust gas, a part thereof may be condensed and adhere to the slag surface in the kiln. In this case, it is necessary to spray an acidic aqueous solution having a pH of 4 or less on the slag, remove heavy metal chips attached thereto, and then wash the slag with water. Fossil fuels (A fuel oil, kerosene)
Is generally used, which leads to an increase in running cost.

[0008]

DISCLOSURE OF THE INVENTION In view of the above-mentioned prior art, the present invention makes it possible to produce strong fine aggregate containing no coarse particles at low cost, and to convert heat generated by the combustion of waste into a clean gas. It is an object of the present invention to provide an apparatus for recovering slag from waste, which can be used effectively, and in which it is particularly advantageous to use a gasification and melting furnace. Note that crystallization in the present invention does not mean complete crystallization, but may partially crystallize, and includes cases where there is a significant difference in strength as compared with amorphous ones.

[0009]

In order to solve the above-mentioned problems, the present invention provides a slag recovery apparatus for subjecting a molten slag obtained by treating waste to a high temperature to water cooling and crystallizing as a granulated slag in a rotary kiln, In particular, in a slag recovery device having a molten slag generation device that treats waste materials at a high temperature, a water granulation device that water-cools the obtained molten slag to form granulated slag, and a rotary kiln that crystallizes the granulated slag, An apparatus for recovering slag from waste, characterized in that a slag crushing apparatus is provided before or after the rotary kiln.

[0010] In the slag recovery device, the rotary kiln may be provided with a ceramic heat exchanger used as a heat source for recovering heat generated by high-temperature treatment of the waste, and using a hot air as a heat source. Can be installed upstream of the rotary kiln. Further, in the slag recovery device of the present invention, the molten slag generation device includes a fluidized bed gasification furnace for gasifying waste, a gaseous substance discharged from the fluidized bed gasification furnace, and a char at a higher temperature. It is good to consist of a melting furnace that slags incombustibles or non-gasifieds while gasifying or gasifying and burning, and a rotary kiln raises the temperature of the granulated slag to the crystal growth temperature and maintains it at a constant temperature. It can have a temperature control mechanism.

[00011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an inexpensive production of strong fine aggregate containing no coarse particles will be described. The means for producing granulated slag is basically a simple method often used in the conventional method, that is, a method in which the molten slag is immediately brought into direct contact with water, rapidly cooled, and reduced in diameter. By using a rotary kiln, heat transfer is improved, and a sufficiently crystallized slag can be obtained even when the temperature rise time to the reheating set temperature is about 25 minutes and the reheating set temperature holding time is about 10 minutes. The granulated slag is subjected to a rotary kiln, reheated, and then crystallized after production, so that the slag exhibits a natural color with a slightly ocher tint, and can produce a strong slag that does not contain dangerous needle-like substances when touched. Slag crystallizes in a temperature range between the glass transition point and the liquidus temperature (or melting point).

In the process of crystal precipitation, an extremely small crystal called a crystal nucleus is formed first, and then the crystal grows around the crystal nucleus. The rate at which the crystal nucleus formation and crystal growth progress is shown in FIG. As such, it is known that there is an optimum temperature for each. This is because when the temperature is lower than the optimum temperature, the energy for arranging the constituent atoms is insufficient, and when it is on the high temperature side, the energy becomes conversely excessive, and the crystal once arranged in a crystal again becomes disordered. This is because he will return. Then, as shown in FIG. 7, the optimum temperature for crystal nucleation exists in a lower temperature range than the crystal growth.
Therefore, as a thermal operation for precipitating crystals efficiently, the melt is once cooled (water-cooled) and then reheated so that the rates of crystal nucleation and crystal growth are maximized.

[0013] Sewerage Association Journal Transactions (Vol. 28, No.
324, P82), the nucleating agent is Fe
Examples include ₂ O ₃ , TiO ₂ , ZrO ₂ , V ₂ O ₅ , NiO, Cr ₂ O ₃ , and P ₂ O ₅ as a nucleation promoter, but waste (municipal waste, sewage sludge, etc.) Some of these are included and do not need to be actively added. Waste, especially municipal ash, has a melting point of 1300-1400.
° C and the glass transition point are estimated to be around 600-900 ° C.
And, the crystal nucleation temperature is 10 degrees with respect to the glass transition point.
５０50 ° C. higher and the crystal growth temperature is 50
Although there is a report that the temperature is lower than １００100 ° C., as shown in FIG. 7, the width is considered to be wider, the crystal nucleation temperature range is approximately 600 to 1000 ° C., and the crystal growth temperature is approximately 700 to 1300 ° C. There will be.

The slag temperature at the time of charging the slag into the rotary kiln is low because the slag is cooled. If the temperature is set at 900 to 1200 ° C.,
A lower temperature range, that is, a crystal nucleus forming temperature range is always passed, and thus is preferable for crystallization. Depending on the composition and the like of the actual waste, there is a possibility that the temperature is out of this range. However, if necessary, the temperature may be changed within the range of the melting point and the glass transition point. Although the optimal heat treatment time for slag is said to be 2 hours or more, a rotary kiln has good heat transfer, and about 10 minutes is sufficient for crystallization. Here, the residence time has a temperature distribution in the rotary kiln, and of the total residence time of the slag, the time that can be maintained at the set temperature is 1%.
This means about 0 minutes, which is the residence time in the vicinity of the kiln burner. Thus, a solid slag crystallized by the rotary kiln can be obtained.

In addition, by providing a slag crushing device at a stage before or after the rotary kiln, it is possible to crush slag having a large particle size in the granulated slag and adjust the particle size to use all of the slag as fine aggregate. It is possible. That is, although the water granulation method is simple, mechanical crushing is required for large particle diameters for effective use. Further, in the rotary kiln, the angle of the slag is reduced by the rotation, the needle-like projections that are dangerous to touch are eliminated, the natural color is exhibited, and the quality of the slag can be improved. The crusher is preferably in front of the rotary kiln. Since the slag is not very strong in the first stage, the crusher used can also use a hammer crusher that rotates a plurality of hammers and crushes by the impact. If a crusher is placed in the subsequent stage, the slag is strong, so it is difficult to crush. In the hammer crusher, the mixed slag having a particle size of more than about 5 mm can be reduced to 5 mm or less (fine aggregate).

Next, the point that the heat generated by the combustion of the waste used as the heat source of the rotary kiln is subjected to heat exchange and used as a clean gas will be described. The heat generated by the combustion of the waste exchanges heat with clean air in a ceramic heat exchanger. This is because if high-temperature exhaust gas is passed directly through a rotary kiln, slag may be contaminated by the exhaust gas. The ceramic heat exchanger has high heat resistance, and the air obtained here is directly guided to a rotary kiln and used as a heat source for the rotary kiln. In a rotary kiln, slag is crystallized by this heat, but the shortage of heat is supplementarily heated by a burner. The temperature in the rotary kiln can be adjusted by adjusting the flow rate of clean air and the flame of the burner. Also, it is better to place the blower in front of the rotary kiln. If it is placed at a later stage, clean air may pass through the slag and be contaminated by dust and the like generated in the kiln, and the installation conditions of the blower such as high-temperature corrosion resistance become severe.

By arranging the blower at the front stage, the air flowing there is clean, and there is not much problem other than heat resistance of about 700 ° C. (this is sufficiently possible at present). When this is applied to a gasification and melting furnace, clean air can be preheated by the heat obtained from the combustion of waste, and it can be used as it is as a part of the heat source of the rotary kiln, which is energy efficient. Dust is contained in the hot air exhaust gas discharged from the rotary kiln (about 2 to 4% of the slag input to the rotary kiln), and if this is captured by a dust collector such as a bag filter, it can be used for asphalt pavement (The filler has a role of filling the gaps in the aggregate together with the asphalt to improve the stability and durability of the mixture, and has a particle size standard of 75 μm or less.) Department can be used effectively. Crystallized slag reheated in a rotary kiln has a particle size of about 0.25 mm or less that is scattered to the exhaust gas side. Depending on the purpose, the particle size may be adjusted by adding the dust component to the reheated slag. it can.

Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is an example of an overall flow of a gasification and melting system provided with a waste slag recovery device of the present invention. The reference numerals in the figure will be described, but those common to FIG. 6 will be omitted. However, reference numeral 1 in FIG. 1 particularly indicates a rotary melting furnace in the melting furnace. In FIG. 1, 11 is a gasifier, 12 is an incombustible discharger, 13 is a vibrating sieve, 14 is a hammer crusher, 15 is a blower, 16 is a rotary kiln, 17 is a burner, 18 is a ceramic heat exchanger, and 19 is waste heat. Boiler, 20 is an air preheater, 21 is a economizer, 22 is a bag filter, 23 is a steam turbine, 24 is an induction blower, 25
Is a chimney, d is waste, e is incombustibles + valuable metals, f is gaseous product, g is flame, h is air, i is condensate, j is slaked lime,
k indicates collected ash.

The waste d is charged into the gasification furnace 11 and
It is gasified in a fluidized bed at 450-600 ° C. under a reducing atmosphere. The fluidized medium of the fluidized bed is sorted by the vibrating sieve 13, and the incombustibles + valuable metal e is also sorted by the incombustibles discharge device 12 and the vibrating sieve 13. The gaseous product f including char generated in the gasification furnace is led to the swirling melting furnace 1. The swirling melting furnace 1 can realize high-temperature combustion at about 1400 ° C. using only a gasification reaction product containing char generated in the gasification furnace 11. In the swirling melting furnace 1, high-temperature load combustion can be performed, and the char contained in the gas is blown toward the furnace wall and burned due to the centrifugal force accompanying the swirling flow. In this manner, complete combustion of the char is possible, and a device for reburning the char is not required.

Exhaust gas of about 1400 ° C. from the swirling melting furnace 1 is heat-recovered by the ceramic heat exchanger 18, waste heat boiler 19, air preheater 20, and economizer 21, and the bag filter 2
After the dust is removed in step 2, the chimney 2
5 to the atmosphere. The condensate i is preheated in the economizer 21, and then vaporized in the waste heat boiler 19,
Sent to The bag filter 22 removes dust and the like, but supplies slaked lime j in the previous stage to remove HCl and the like in the exhaust gas. Or bring it to a final disposal site. Next, in the present invention, the molten slag a from the rotary melting furnace 1 becomes granulated slag b in the granulated water tank 7 and is sent to the hammer crusher 14. Granulated slag b is
It is continuously struck by a hammer rotating at a high speed, and is accelerated to collide with a rebound plate at a position facing the hammer or to collide with a bounced mass, and is discharged downward while being crushed. A plurality of hammers are mounted through pin holes.

The particle size of the crushed material is adjusted by the gap of a bar provided below the casing. Further, a method may be used in which discharged products are sieved without using a bar, and excessive grains are repeatedly crushed. However, when making fine aggregate (all pass through a 10 mm sieve and pass through 85% or more by mass) with a hammer crusher 14, the maximum particle size is regulated by the gap between the bars, so the fine aggregate having a maximum of 5 mm If you adjust the bar gap to make
Those having a particle size of m do not come out. Hammer Crusher 1
The granulated slag b from 4 is supplied to the rotary kiln 16
The temperature is maintained at a temperature of 900 to 1200 ° C. for about 10 to 30 minutes and reheated, and the granulated slag b is crystallized. Next, the crystallinity of the granulated slag that had not been reheated and the granulated slag that had been reheated at 1100 ° C. for 25 minutes in a rotary kiln were evaluated using an X-ray diffraction method.

As the evaluation method, the three-peak method is most commonly used. In this method, the sum of the three large peaks of the crystal in the X-ray diffraction diagram is obtained, and the sum is obtained from the ratio of that of the standard sample that has been crystallized to the maximum. Relative crystallinity (%) = sum of the three major peak heights of the sample / sum of the three major peak heights of the standard sample × 100 The method of preparing the standard sample is as follows. (1) A sample crystallized by a two-step heat treatment is used as a standard sample. (Nucleation: 800-850 ° C. × 1-2 h Crystal growth: 10
(50-1100 ° C. × 2-4 h) (2) A cooling rate of 1 ° C./min is used as a standard sample. This time, a standard sample was not prepared, but the sum of the heights of the three major peaks of the sample was compared. First, the rotary kiln test will be described.

Table 2 shows the analytical values of the main components of the granulated slag used.

[Table 2]

The specifications of the rotary kiln are as follows. (1) Method; Direct heating type: Countercurrent type (2) Dimensions: Inner lining inner diameter: 540 mm x 10350 mm
L (3) Slope; 2/100 (fixed) (4) Heating temperature: Maximum: 1200 ° C (5) Operating conditions; Slag supply amount: 100 kg / h × 75
min (Kiln residence time) Kiln rotation speed: 1.5 rpm (6) Fuel; Kerosene (7) Blower (for kiln hot air feed); 3.7 kW, 36
00 rpm, 600 mmAg, 14 m ³ / min

FIG. 2 shows a flow chart around the rotary kiln. 210 kg of granulated slag having a water content of about 5% was charged into a raw material hopper. The rotary kiln is sufficiently preheated to reach a set temperature of 1100 ° C. FIG. 3 shows the temperature distribution in the rotary kiln after reaching the steady state. If the slag moves at a constant speed in the rotary kiln,
As shown in FIG. 3, since the estimated length of the crystal growth zone (1100 ° C.) is 3500 mm and the total length of the rotary kiln is 10350 mm, the residence time of the crystal growth zone is 75 minutes because the kiln residence time is 75 min.
min × 3500mm / 10350mm = 25min
Becomes This time, we did not create a so-called standard sample,
A comparison of the sum of the three major peak heights of the sample was made.

As a result, the crystallinity of the granulated slag that had not been reheated was 11% as compared with that obtained by reheating in a rotary kiln at 1100 ° C. for 25 minutes. Is shown. The granulated slag that had not been reheated was black, whereas the reheated slag was slightly ocherish gray (natural color) and strong. Also, the reheated slag was free of dangerous needles to the touch. However, particles of 0.25 mm or less were blown off by the hot air of the kiln and did not exist. Rotary kiln test conditions are as follows: time from normal temperature to set crystal growth temperature is 7
5min-25min = 50min, and the time to the crystal growth holding temperature was 25min.

The granulated slag of the same rod is pulverized to 75 μm or less, and 30 g of the granulated slag is placed in a 40 ml crucible. An electric furnace heating test is performed under the same heating conditions as those of the rotary kiln (heating time: 50 min, holding temperature: 1100 ° C., holding time: 25 min). As a result, 3247 cps in the rotary kiln test and 3057 cps in the electric furnace reheating test were performed with the three peak sums.
The results were almost the same, the crystallinity did not change, and the consistency of the retest was maintained. According to the results of the electric furnace reheating test alone, there is no difference in the crystallinity between the holding temperature of about 1000 ° C. and 1150 ° C., and even if the heating time is reduced to 25 min or the holding time is also reduced to 10 min, Has little effect on crystallinity. This is presumed to be the same tendency in a rotary kiln, and the rotary kiln has a good heat transfer property and can reduce the time for crystallization.

If it is necessary to adjust the particle size according to the purpose of use before shipment, a vibrating sieve or the like is required before or after (particularly after) the rotary kiln 16. Further, since the crystallized granulated slag b discharged from the rotary kiln 16 has a high temperature, the crystallized granulated slag b is once received in a container, and air h is exchanged with the slag layer filled in the container after heat exchange. The heated air can be sent to the rotary kiln 16 and used as a part of the heat source. The heat source of the rotary kiln 16 is to supply clean air h to the preheater 20.
The temperature is raised to about 250 ° C. in the furnace, and further raised to about 700 ° C. in the ceramic heat exchanger 18 (the temperature at the gasification and melting furnace outlet is about 1400 ° C.), but the temperature is low for crystallization in a rotary kiln. Therefore, it is necessary to perform auxiliary heating by the flame g of the burner 17 using fossil fuel (A heavy oil or kerosene).

The direct heating type rotary kiln includes a countercurrent type and a cocurrent type, and FIG. 1 shows a countercurrent type. Although about 5% of water remains in the granulated slag, a counter-current type is more preferable than a co-current type in order to quickly evaporate the evaporate out of the kiln and increase the thermal efficiency. The clean air h is sent to the rotary kiln 16 by the blower 15. The granulated slag b is not contaminated because it is crystallized by the clean air h. In addition, by placing the blower 15 in front of the rotary kiln, there is no possibility of contamination by dust or the like generated in the rotary kiln 16, and high-temperature corrosion resistance and the like do not need to be considered when installing.

Next, the ceramic heat exchanger 18 will be described. FIG. 4 is an overall view of the ceramic heat exchanger 18, and FIG. 5 is a view taken along the line AA 'in FIG. 4 and 5 will be described. 26 is an outer tube, 27 is an inner tube, 28
Denotes an expansion joint, 19 and 30 denote spacers, 30 denotes a low temperature side gas inlet nozzle, and 32 denotes a low temperature side gas outlet nozzle. For details of the ceramic heat exchanger, refer to Japanese Patent Application No. 63-12 / 1988.
1827 (described in the ceramic bayonet heat exchanger. The ceramic heat exchanger 18 is composed of a plurality of bayonet heat exchangers. Since the structure based on the thermal expansion difference is completely free of movement, the outer tube outer fluid (exhaust gas from the swirling melting furnace 1 in this case; about 1400
° C) and a fluid in the pipe (clean air h: about 250 ° C) is a heat exchanger of a type used when the temperature difference is extremely large. Since the outer tube 26 is made of ceramic, crushing due to thermal shock does not occur.

Also, the hot air exhaust gas discharged from the rotary kiln 16 contains dust, and as shown in FIG. 1, does not return directly to the gasification and melting system side, but instead includes a dust collector ( If a bag filter or the like is provided, only fine dust is collected here and can be reused as filler or the like. Crystallized slag reheated by the rotary kiln has a particle size of about 0.25 mm or less that scatters to the exhaust gas side. Depending on the purpose, particles collected by the dust collector on the exhaust gas side may be added to this reheated slag. And add
The particle size can also be adjusted.

[0032]

According to the present invention, the following effects can be obtained. (1) According to the present invention, granulated slag which is low in strength but can be produced with simple equipment is also high in strength, natural color,
Dangerous needle-like substances and substances that do not contain large particle size parts can be replaced, and the application range of recycling to fine aggregates and the like has expanded. (2) Since the heat generated by the combustion of the waste is heat-exchanged in the ceramic heat exchanger, the heat can be effectively used, and the slag is not contaminated by the heat source gas during the firing of the rotary kiln. This is advantageous in the case of a gasification melting furnace in that heat recovery and effective use of heat are efficiently performed in the same system. (3) The blower for sending the heat source air of the rotary kiln does not require high-temperature heat resistance and corrosion resistance, and the system can be easily assembled. (4) The rotary kiln can be effectively used as dust filler in hot exhaust gas.

[Brief description of the drawings]

FIG. 1 is an overall flow diagram of a waste gasification and melting system provided with a slag recovery device of the present invention.

FIG. 2 is a flowchart around a rotary kiln.

FIG. 3 is a graph showing a temperature distribution in a rotary kiln.

FIG. 4 is an overall configuration diagram of a ceramic heat exchanger used in the present invention.

FIG. 5 is a view taken in the direction of arrows AA ′ in FIG. 2;

FIG. 6 is a schematic configuration diagram of a conventional granulated slag cooling and solidifying apparatus.

FIG. 7 is a graph showing changes in a crystal nucleation rate and a crystal growth rate depending on temperature.

[Explanation of symbols]

1: melting furnace, 2: granulated trough, 7: granulated water tank, 8: slag carry-out conveyor, 9: slag pit, 10: circulating water pump, 11: gasification furnace, 12: incombustibles discharge device, 13: vibration Sieve, 14: hammer crusher, 15: blower, 1
6: rotary kiln, 17: burner, 18: ceramic heat exchanger, 19: waste heat boiler, 20: air preheater,
21: economizer, 22: bag filter, 23: steam turbine, 24: induction blower, 25: chimney a: molten slag, b: granulated slag, c: water, d: waste, e: incombustibles + valuable Metal, f: gaseous product, g:
Flame, h: air, i: condensate, j: slaked lime, k: trapped ash

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takahiro Oshita 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation

Claims (6)

[Claims] 1. A slag recovery apparatus comprising: an apparatus for producing molten slag for treating waste materials at a high temperature; a water granulating apparatus for cooling the obtained molten slag with water to obtain granulated slag; and a rotary kiln for crystallizing the granulated slag. An apparatus for recovering slag from waste, wherein an apparatus for crushing slag is provided before or after the rotary kiln. 2. The rotary kiln according to claim 1, wherein a ceramic heat exchanger used as a heat source for recovering heat generated by high-temperature treatment of the waste is installed upstream. Slag recovery device. 3. The apparatus for collecting slag from waste according to claim 2, wherein the rotary kiln is provided with a blower for sending hot air as a heat source upstream of the rotary kiln. 4. The apparatus for collecting slag from waste according to claim 2, wherein the rotary kiln is provided with a dedicated dust collector for removing dust in an exhaust gas passage. 5. The apparatus for producing a molten slag further comprises the steps of gasifying or gasifying a fluidized bed gasifier for gasifying waste and a gaseous substance and char discharged from the fluidized bed gasifier at a higher temperature. The slag recovery device from waste according to claim 1 or 2, comprising a melting furnace that burns and converts incombustibles or non-gasified substances into slag. 6. The disposal according to claim 1, wherein the rotary kiln has a temperature control mechanism for raising the temperature of the granulated slag to a crystal growth temperature and maintaining the temperature at a constant temperature. A slag recovery device from objects.