JP2004361025A - Slag ladle and ladle assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slag ladle capable of manufacturing crystallized solid slag at low cost while eliminating the need for a slag heater. <P>SOLUTION: The slag ladle 1 comprises a bottom plate 3 and four faces of side plates 5 in inverted trapezoidal shape. The ladle 1 has a capacity of 0.2-0.4 m<SP>3</SP>, a bottom area of 0.07 m<SP>2</SP>or larger and a depth of 0.3 m or deeper, and the side plate 5 has a draft angle of 15° or greater. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is to melt and cool and solidify the molten slag from a melting furnace for directly melting and processing municipal waste and industrial waste, or a melting furnace for melting and processing incineration residues such as municipal waste and industrial waste. And a collection of ladle for slag.
[0002]
[Prior art]
Generally, municipal solid waste and industrial waste are often incinerated. The incineration residue whose volume has been reduced by incineration has been landfilled. However, it is becoming increasingly difficult to secure landfill sites, and the incineration residue is melted and solidified by cooling in a melting furnace, and is being recycled as roadbed material, aggregate, blocks, and the like.
[0003]
Various types of melting furnaces are used, such as a vertical melting furnace. In a vertical melting furnace, the materials to be treated such as incineration residues and sludge are dried and humidified, and if necessary, a binder is added to form briquettes, and limestone as a basicity adjuster and lump coke as a combustion agent are used as raw materials. The furnace is charged into the vertical melting furnace through the inlet, preheated air is sent into the furnace, and the furnace is heated by the combustion heat of lump coke, and the briquettes are melted together with limestone. The molten slag is discharged from a tapping gutter at the bottom of the vertical melting furnace. Ladles are used to receive molten slag from a tapping gutter (see, for example, Patent Document 1).
[0004]
The molten slag that is discharged at a high temperature becomes a vitrified solidified slag when rapidly cooled, but can be converted into a crystallized solidified slag by controlling the cooling temperature.
Solidified slag obtained by taking molten slag into a ladle and gradually cooling and crystallizing it has the same strength as natural stone, and fully satisfies the quality standards for effective use as roadbed material, aggregate, block, civil engineering and building materials Will do. This solidified slag is crushed into crushed stone to be used as roadbed material and aggregate, or the crushed material is mixed with cement to form a block, or the powdered material is kneaded, molded and fired with another ceramic material. It can be used as a panel made of ceramics.
[0005]
In order to commercialize the solidified slag cooled by the ladle as a roadbed material and an aggregate, it is necessary to go through various processing steps such as discharge, crushing, magnetic separation, and classification. The easiest way to discharge the solidified slag from the ladle is to tilt or tip the ladle with a crane or the like, and drop the solidified slag from the ladle by its own weight. However, when the solidified slag is dropped by its own weight and discharged from the ladle, if the ladle is large, the solidified slag becomes a large lump and it is difficult to put it into the crusher in the next crushing step. Therefore, coarse crushing is required before the slag is put into the crusher. However, the crystallized solidified slag has high strength, and the work of coarsely crushing the slag is troublesome.
[0006]
If the ladle is made smaller, the solidified slag that is discharged can be made into a small lump, but if there is a large amount of molten slag, the ladle must be replaced frequently and the work becomes complicated, and one Since the amount of heat of the molten slag per ladle is reduced, the slag is rapidly cooled by the outside air and crystallization is difficult to proceed.
For this reason, heat is applied to the slag in the ladle using a slag heating device such as a crystallization furnace, the cooling rate is adjusted, and crystallized solidified slag is obtained. The solidified slag crystallized in this way is of high quality that conforms to the quality standards for roadbed materials and the like.
[0007]
[Patent Document 1]
JP-A-11-118133
[Problems to be solved by the invention]
However, the use of a slag heating device increases the production cost of crystallized slag because external energy must be applied to adjust the cooling rate.
The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to eliminate the need for a slag heating device and to produce a slag ladle and a ladle that can produce crystallized solidified slag at low cost. Is to provide an aggregate of
[0009]
[Means for Solving the Problems]
The present invention has the following configuration to solve the problem. The slag ladle according to the first aspect of the present invention is a ladle for receiving molten slag from a melting furnace and cooling and solidifying the molten slag. The ladle has a bottom plate and side plates, and has a volume of 0.2. ０．４0.4 m ³ , bottom area 0.07 m ² or more, depth 0.3 m or more, draft angle of side plate 15 ° or more.
[0010]
When the volume of the ladle is smaller than 0.2 m ^{3, the} amount of heat of the molten slag per ladle is small, the cooling rate in the ladle is increased, the crystallization of the solidified slag hardly proceeds, and vitrification occurs. Solidified slag containing many parts will be formed. In addition, the amount of molten slag that can be processed by one ladle decreases, and the ladle needs to be replaced frequently, which complicates the operation. If the volume of the ladle is larger than 0.4 m ^{3, the} amount of heat of the molten slag per ladle is large, the cooling rate in the ladle is slow, and the solidified slag crystallized with large lump and high strength And the large lumps of the solidified slag must be coarsely crushed. When the volume of the ladle is set to 0.2 to 0.4 m ³ , it is possible to obtain a crystallized solidified slag of a size that can be easily handled in a subsequent processing step, and a particle size distribution conforming to a quality standard of a roadbed material and the like. Solidified slag is easily produced.
[0011]
Under the condition that the volume of the ladle is 0.2 to 0.4 m ³ , if the bottom area of the ladle becomes smaller than 0.07 m ² , the area of the side plate becomes relatively large. When the area of the side plate increases, the amount of heat radiated from the ladle to the air per hour increases, the cooling rate in the ladle increases, and crystallization of the solidified slag becomes difficult. When the depth of the ladle is shallower than 0.3 m, the opening area of the ladle becomes relatively large, and the amount of heat dissipated from the ladle to the air per hour increases. When the bottom area of the ladle is 0.07 m ² or more and the depth is 0.3 m or more, the cooling rate of the solidified slag in the ladle does not become too fast, and the size of the solidified slag discharged from the ladle Has a size suitable for the subsequent processing steps.
[0012]
When the solidified slag is discharged from the ladle, if the draft angle of the side plate is smaller than 15 °, it is difficult to discharge the solidified slag from the ladle. When the draft angle is 15 ° or more, when the ladle is inclined or turned over, the solidified slag is discharged by its own weight, and the work becomes easy.
An assembly of the slag ladle according to the second aspect of the invention is configured by interconnecting a plurality of the slag ladles of the first aspect.
[0013]
According to the invention of claim 2, the molten slag for a plurality of ladles can be continuously put in one assembly. Therefore, even when the amount of hot water per unit time is large, it is not necessary to frequently exchange the aggregate. The molten slag is distributed to the ladles constituting the assembly and enters, and the molten slag that flows out can be crystallized solidified slag of an appropriate size.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The configuration of the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a ladle for slag according to the present embodiment, and FIG. 2 is a sectional view taken along line AA of FIG.
The ladle 1 for slag is composed of a square bottom plate 3 and four side plates 5 having an inverted trapezoidal shape. The upper edge of the side plate 5 is used when the ladle 1 is moved or solidified slag is discharged. A lifting hand (not shown) for lifting and tilting is mounted.
[0015]
The volume of the ladle 1 is 0.2-0.4 m ^3, the bottom area is 0.07 m ² or more at the bottom plate 3, the depth of the inner or 0.3 m, the draft θ of the side plates 5 is more than 15 ° . Note that the draft θ of the side plate 5 is an inclination angle of the side plate 5 with respect to the center axis CL direction of the ladle 1 (see FIG. 2).
Next, the operation will be described.
[0016]
The case where the ladle 1 is used in, for example, a conventional vertical melting furnace will be described. The incineration residues and the like become molten slag in the vertical melting furnace, and the molten slag flows out of a tapping gutter at the bottom of the vertical melting furnace and flows into the ladle 1.
The ladle 1 has a volume of 0.2 to 0.4 m ³ , a bottom area of 0.07 m ² or more, and a depth of 0.3 m or more, so that the area of the side plate 5 and the opening of the ladle 5 The area cannot be too large. Therefore, a large amount of heat is not dissipated into the atmosphere from the side plate 5 or the opening of the ladle 1 in a short time.
[0017]
The thermal conductivity of the molten slag is 0.5 to 1.0 W / m · K at 1000 ° C., which is less than 1/30 of the thermal conductivity of iron. Equivalent to insulation materials. When the molten slag is cooled and solidified in the ladle 1, 70 to 90% by mass of the molten slag is gradually cooled at a cooling rate of 2 ° C./min or less due to the heat insulating property of the molten slag itself. The remaining 30 to 10% by mass of the molten slag is cooled at a cooling rate higher than 2 ° C./min.
[0018]
When the molten slag is gradually cooled at a cooling rate of 2 ° C./min or less, it crystallizes and becomes a hardened solidified slag, and when it is cooled at a cooling rate higher than 2 ° C./min, it has many vitrified portions. It becomes slag. Therefore, 70 to 90% by mass of the solidified slag in the ladle 1 is crystallized solidified slag, and the remaining 30 to 10% by mass is solidified slag having many vitrified portions.
[0019]
The solidified slag is discharged from the ladle 1 and crushed in a subsequent crushing step.
When the ladle 1 is lifted up and tilted via the handle, the solidified slag in the ladle 1 is discharged out of the ladle 1. Since the draft θ of the side plate 5 is 15 ° or more, if the ladle 1 is tilted, the solidified slag slides down on the surface of the side plate 5 by its own weight, so that the work of discharging the solidified slag becomes easy.
[0020]
Most of the crystallized solidified slag occupying 70 to 90% by mass of the total solidified slag becomes crushed pieces having a particle size of 2.5 mm or more in the crushing step. Most of the remaining solidified slag having many vitrified portions of 30 to 10% by mass becomes crushed pieces having a particle size of 2.5 mm or less in the crushing step.
When the crushed solidified slag is used as an aggregate, crushed pieces having a particle size of 2.5 mm or more can be used as coarse aggregates, and crushed pieces having a particle size smaller than 2.5 mm can be used as fine aggregates.
[0021]
When crushed solidified slag is used as a roadbed material, the crusher orchid standard requires that the ratio of the particle size of 2.36 mm or less in the particle size distribution be 5 to 35% by mass.
When 70 to 90% by mass of the molten slag is gradually cooled at a cooling rate of 2 ° C./min or less into a solidified slag in the ladle 1, the remaining 30 to 10% by mass of the molten slag is converted into a vitrified portion. And the solidified slag having many vitrified portions tends to become crushed pieces having a particle size of 2.36 mm or less in the crushing step. Therefore, it is possible to easily produce solidified slag that conforms to the crusher run standard.
[0022]
Therefore, by receiving the molten slag in the ladle 1 and cooling and solidifying the molten slag in the ladle 1, it is possible to easily obtain a solidified slag having an appropriate particle size distribution as a roadbed material or an aggregate. At this time, in the ladle 1, the cooling rate is adjusted by utilizing the fact that the molten slag has excellent heat insulating properties, and crystallized solidified slag is obtained. In order to control the cooling rate, the inside of the ladle 1 is controlled. There is no need to heat the molten slag. That is, there is no need to apply external energy such as heat to the molten slag in the ladle 1, and the production cost of the solidified slag is reduced. Since the slag heating device is not required for the ladle 1, the equipment cost is also reduced.
[0023]
Next, a configuration of a second exemplary embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a perspective view of an assembly of slag ladle according to the present embodiment. The same components as those in the first embodiment are denoted by the same reference numerals.
Three ladles 1 having the same configuration as the ladle according to the first embodiment are connected adjacent to each other in a row, and form an assembly 2 on a cart 11. The upper edges of the side plates 5 of the adjacent ladle 1 are joined to each other. The height of the joining portion 9 between the upper edges is lower than the height of the outer edge 7 of the assembly 2.
[0024]
Next, the operation will be described.
A case where a molten slag is received from a conventional vertical melting furnace using this assembly 2 will be described. First, the carriage 11 is moved, and for example, the ladle 1 at the right end in FIG. 3 is positioned below the tapping gutter at the bottom of the vertical melting furnace, and the molten slag discharged from the vertical melting furnace is poured into the ladle 1.
When the amount of molten slag is larger than the capacity of one ladle 1, the carriage 11 is moved before the ladle 1 at the right end is full, and the center ladle 1 is positioned below the ladle. Even if the rightmost ladle 1 is full before the central ladle 1 is positioned below the tapping gutter, the molten slag overflows from the rightmost ladle 1 to the central ladle 1 beyond the joint 9. . Since the height of the joining portion 9 is lower than the height of the outer edge 7 of the aggregate 2, the molten slag does not overflow out of the aggregate 2.
[0025]
When the center ladle 1 is almost full, the carriage 11 is moved again to position the leftmost ladle 1 below the tapping gutter, and the molten slag is poured into the ladle 1.
Therefore, when the molten metal slag has a large amount of hot water per unit time, the number of ladles 1 constituting the aggregate 2 can be increased, and the capacity of the aggregate 2 can be made to correspond to the molten metal slag hot water amount. It is not necessary to exchange the aggregate 2 frequently. The molten slag is distributed to each of the ladles 1 constituting the assembly 2, and the molten slag that flows out of the ladle can be converted into a solidified slag having a suitable size and crystallized. In addition, since the empty ladle 1 can be positioned below the tapping gutter by a simple operation of moving the carriage 11, the tapping operation is simplified.
[0026]
In each of the above embodiments, the shape of the bottom plate 3 of the ladle 1 is square, and the shape of each side plate 5 is an inverted trapezoid. However, it is a matter of course that the shape is not limited to such a shape. The shape of the bottom plate 3 can be rectangular. As shown in FIG. 4, the shape of the bottom plate 3 can be a polygon such as a hexagon. As shown in FIG. 5, the shape of the bottom plate 3 can be circular.
In addition, in the second embodiment, the number of the ladle 1 constituting the aggregate 2 is three, but the number of the ladle 1 to be connected can be appropriately increased or decreased according to the amount of molten slag discharged from the molten metal. Of course.
[0027]
Further, in the second embodiment, each ladle 1 constituting the assembly 2 is sequentially positioned below the tapping gutter at the bottom of the vertical melting furnace to receive the molten slag. It is also possible to leave 1 below the tapping gutter. In this case, first, the ladle 1 below the hot water gutter becomes full. And since the joining part 9 is lower than the height of the outer edge 7, the molten slag overflows the joining part 9 from the full ladle 1 to the adjacent empty ladle 1, and forms the aggregate 2 in order. The molten slag enters each ladle 1 to be melted.
[0028]
【The invention's effect】
Since the present invention is an aggregate of a slag ladle and a ladle as described above, a slag heating device is not required, and a slag ladle and a ladle capable of producing crystallized solidified slag at low cost. There is an effect that an aggregate can be provided.
[Brief description of the drawings]
FIG. 1 is a plan view of a ladle according to a first embodiment.
FIG. 2 is a sectional view taken along line AA of FIG.
FIG. 3 is a perspective view of a ladle assembly according to a second embodiment.
FIG. 4 (i) is a plan view of a ladle having a polygonal bottom plate, and FIG. 4 (ii) is a sectional view taken along line BB in FIG. 4 (i).
5 (i) is a plan view of a ladle having a circular bottom plate, and FIG. 5 (ii) is a cross-sectional view taken along line CC in FIG. 5 (i).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ladle 2 Ladle aggregate 3 Bottom plate 5 Side plate 7 Outer edge 9 of aggregate Ladle side plate of adjacent ladle 11 Bogie θ Side draft angle

Claims (2)

A ladle for receiving and cooling and solidifying molten slag discharged from a melting furnace, comprising a bottom plate and side plates, having a volume of 0.2 to 0.4 m ³ and a bottom area of 0.07 m ² or more. A slag ladle having a depth of 0.3 m or more and a draft angle of the side plate of 15 ° or more. An assembly of slag ladles, wherein a plurality of the slag ladles according to claim 1 are connected to each other.

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