JPS5915715B2 - Disintegration method of fly azure sintered material - Google Patents

Description

[Detailed description of the invention] The present invention produces a sintered product in a moving grate type sintering machine.

Fly ash sintering that effectively crushes the lumpy sintered material (hereinafter referred to as intermediate product) discharged from the sintering machine during manufacturing, and allows production of product aggregate with the highest possible yield. It is about how to disintegrate things. The waste gas generated from boilers, incinerators, etc. contains a large amount of extremely fine dust (fly ash: generally 200 mesh or less), which is collected by electrostatic precipitators, etc., but the use of such fly ash is As a technology, a technology to produce lightweight aggregate by granulation and sintering has been proposed.

5 FIG. 1 is a schematic explanatory diagram showing a general fly ash sintering process, in which raw pellets 1a made by mixing fly ash with powdered carbonaceous material such as fine coal powder and granulating water using water as a binder are placed in a hopper 1Ab. - The raw pellets 1a are fed onto the movable grate, but prior to that, the sintered product aggregate Ib is spread from the hopper 10IB onto the grate 3 to form the bedding 2. 2, forming a layer and moving in the direction of the arrow.

After passing through a drying and preheating section 4 if necessary, ignition combustion occurs in a sintering section 5 15, and further, if necessary, passing through a heat retaining section 6 for heat retention with hot air, and then passing through an air cooling section T. The product is slowly cooled and discharged from the end of the moving grate as the above-mentioned intermediate product. 8 is a sizing and sieving process in which the lumpy sintered material is crushed, sized and separated into product aggregate and defective products.

By the way, the above-mentioned intermediate products rarely retain the shape of raw pellets, and as shown in FIG. 2, products with various shapes are obtained. To be more specific, (hereinafter referred to as fused material 12), the surface of the sintered layer at point a has received heat of more than 500 yen and the pellets 9 have completely fused together, making it impossible to separate the pellets (hereinafter referred to as fused material 12 ), (b) Although the sintering of the pellets 9 has been completely completed, the edges of the pellets 9 adhere strongly to each other on the surface, forming a lump (hereinafter referred to as a lump 13). ) Pellets that have been sintered without adhering to each other and each maintaining an independent spherical shape (hereinafter referred to as single grain 21)
, (d) Particularly in the bottom corners of the sintered layer, the sintering is not completed, so it easily collapses due to the impact received during the crushing and sizing process, resulting in half products or in some cases remaining almost unignited. It consists of dry pellets that can be easily powdered (hereinafter referred to as half-split product 22). On the other hand, the sizing process is configured as shown in FIG. 3, for example, and the intermediate product discharged from the rear end 10 of the sintering machine falls to a grizzly (iron bar sieve) 11 and is crushed into rough pieces Tga. ) and the remaining mixture 14 of (b) (CXd), and the fused material 12 is disposed of by landfilling or the like. On the other hand, the remaining mixture 14 is put into the crusher 15, and the nodules 13 in (b) are separated from the superficial adhesion between the ends by mechanical impact and separated into single granular sintered pellets. Single grain c) and half-split product 2 of (d)
Coarse aggregate product 1 with a predetermined particle size or more enters the sieve 16 together with the second grade
The halved product 22 is separated into a powder material 7 and a powder material, and the half product 22 is discarded together with the fused material 12. However, in the above-mentioned granulation process, since the fused material 12 and the other mixture 14 were to be separated on the grizzly, it was first necessary to release the mutual adhesion of (a) to (d), and the sintering machine discharge port The above-mentioned release is carried out by keeping a considerable distance between the grizzly and the grizzly, but since the falling impact is simply used, the separation of the fused material 12 is insufficient, and nodules 13 and single grains are separated. Thing 21
was sometimes discarded together with the fused material 12.

In addition, since the impact is such as to have the effect of crushing the sintered mixture, it is impossible to avoid a huge impact on the grizzly, and due to the repeated falling impact of the intermediate product, the iron rods etc. that are the components of the grizzly may be damaged. There is a strong possibility that damage such as bending or folding will occur, and therefore, the above-mentioned falling distance cannot be increased. As described above, since the crushing effect of the grizzly itself is insufficient, it cannot be expected to loosen the nodules together, so a crusher is often installed after the grizzly process, but the strength of the sintered pellets is 50%. ~100k9/
It is relatively weak compared to pellets and cannot be said to be a very strong granule, so depending on the capacity of the crusher, good single grains may be crushed, but the production yield of sintered pellets has not improved as much as expected. I couldn't let it happen. The present invention has been made in view of these circumstances, and an object of the present invention is to improve the product yield by crushing intermediate products discharged from a movable grate relatively efficiently.

However, the gist of the crushing method of the present invention is that an inclined plate is installed below the discharge position of the sintering machine, and after the sintered material is dropped onto the inclined plate, it is supplied to the sizing process. It is something.
The present invention will be described below with reference to the drawings, but the description is not intended to limit the present invention, and in keeping with the spirit of the above and below, any appropriate design changes etc. are within the technical scope of the present invention. include. FIG. 4 is a flowchart showing the coarse aggregate production process when the present invention is applied, in which the nodular sintered material discharged from the rear end 10 of the sintering machine first falls onto the inclined iron plate 19. As a result, the adhesion of fused materials, nodules, single grains, halved products, etc. to each other is loosened, and the nodules are also released into individual single grains.

The crushed mixture reaches the grizzly 11 from above the inclined iron plate 19, and is divided into the fused material 12 that could not pass through the iron bar gap of the grizzly 11, and the single grains and half-split products that passed through. will be discarded as well. On the other hand, the single grains and half-split products are separated by a sieve 16 into single grains having a predetermined particle size or larger (here, coarse aggregate product 17) and half-split products (here, defective product 18). The defective products 18 are discarded together with the fused material 12. In the above process, the inclination angle of the inclined iron plate 19 is not particularly limited, but in order to stabilize the crushing effect, it is preferably 30 to 60 degrees with respect to the vertical line, and the reason is as described below.

That is, if the angle between the vertical line and the inclined iron plate is θ, then the fifth a
As shown in the figure, when θ is less than 30 degrees, the inclined iron plate 19
The component P1 of the impact force P when the intermediate product fell, perpendicular to the surface of the inclined iron plate 19, was less than the force necessary to crush the intermediate product, and the intermediate product could not be crushed. As can be understood from the figure, the above-mentioned vertical component P1 increases as θ increases, and the crushing effect of the inclined plate 19 increases. That is, as shown in FIG. 5b, when θ is 30 degrees or more, the vertical component Pla of the impact force P becomes sufficiently large, and the intermediate product falling onto the inclined plate 19 is crushed as expected. However, the 5th c.
As shown in the figure, when θ exceeds 60 degrees, the vertical component Plb becomes excessive, which not only increases the number of half-split products, but also makes it easier for intermediate products that have fallen onto the inclined plate 19 to accumulate on the plate. The next intermediate product falls on top of the intermediate product, increasing the number of collisions between intermediate products or single grains, and increasing the risk of a large increase in the number of defective products. Furthermore, the impact force applied to the inclined plate 19 itself becomes too large, causing the plate surface to cave in, and in order to cope with this, it becomes necessary to increase the wall thickness of the inclined plate. For these reasons, it is recommended that the angle θ of the inclined plate 19'' with respect to the vertical line be 30 to 60 degrees.
Next, the distance between the sintering machine and the inclined plate, that is, the falling height of the intermediate product is 2
It is preferable that the falling height be 5 m. If the falling height is less than 2 m, the force colliding with the inclined plate will be small and the crushing effect will be reduced, as in the case explained in FIG. 5.

On the other hand, if the length exceeds 5 m, the impact force at the time of collision becomes too large, resulting in not only the crushing of the intermediate product but also cracking of the good sintered pellets. Furthermore, if the sintering machine and the inclined plate are too far apart, the height of the post-processing equipment including the sizing process becomes too large, which is inappropriate in terms of equipment design. There are no particular restrictions on the material of the inclined plate used above, as long as it can withstand the fall impact and abrasion of the intermediate product.For example, it is not limited to a single steel plate, but may be reinforced by pouring concrete into a steel frame. You can also use things.

Although FIG. 4 describes the case where only coarse aggregate products are produced, the method of the present invention can be applied to the process of producing both coarse aggregate products 17 and fine aggregate products 20 as shown in FIG. It's okay.

In this case, the fused material 12 separated by Grizzly is transferred to the crusher 1.
6 and crushed, and the fine aggregates here are combined with the powder 18 from the sieve 16 to form a fine aggregate product 20. Examples of the present invention will be described below. First, as a sample raw material,
The intermediate products discharged from the sintering machine were collected, the fused materials and the aggregates were separated into large pieces, and then passed through a sieve to separate them into sintered pellets, sintered unfinished materials, and unsintered powder. The composition ratio was as follows.

Example 1 The above raw material product 100k9 was tilted at 45 degrees to a thickness of 3.
When the mixture was dropped onto a 0U iron plate from a height of 3 m for about 20 seconds, a mixture having the following composition was obtained.

In addition, newly crushed pellets are included in the unfinished sintered materials.
The unsintered powder includes crushed pellets of 5 paulownia or less.

This classification also applies to the following comparative examples. Comparative Example 1 Same as above raw material 100k9 with opening width 30m1! When it was dropped from a height of 3 m for about 20 seconds onto a grizzly with a t1 opening area ratio of 50%, a mixture having the following composition was obtained.

Comparative Example 2 After separating and removing the fused material from the product treated in Comparative Example 1, the product was heated to an opening width of 30 mm and a rotation speed of 40 rpm. p. A mixture having the following composition was obtained when the mixture was passed through a roll-type crusher.

The composition shown was calculated including the fused material separated in advance.

As mentioned above, it can be seen that in the method of Comparative Example 1, a large amount of nodules remained and the crushing was not sufficiently performed.

Therefore, when the nodules were crushed using the method shown in Comparative Example 2, the amount of nodules was reduced to 3.2%, but the addition of the crushing process generated a large amount of unfinished sintered and broken pieces and unsintered powder. The yield of sintered pellets ranged from 57.5% to 64.7%.
It only rose to . That is, when the crusher shown in Comparative Example 2 was used, the nodules could be crushed to some extent, but at the same time the sintered pellets were destroyed, so the yield of sintered pellets was not improved as much as expected. . In contrast, in Example 1, by colliding the sintered material with the inclined plate,
Since the nodules can be completely crushed while suppressing the destruction of the sintered pellets, the yield of sintered pellets can be increased by minimizing the increase in the ratio of unfinished sintered fragments and unsintered powdery materials. I was able to improve it dramatically.

Since the present invention is roughly constructed as described above, the yield of sintered pellets can be dramatically improved by simply installing a simple device called an inclined plate between the sintering machine discharge section and the sizing process. did it.

Furthermore, when it is sufficient to obtain coarse aggregate, the installation of a crusher can be omitted, simplifying the grading process and successfully reducing operating costs.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the sintering process, Figs. 2a-d are explanatory diagrams of the shapes of intermediate product components, Fig. 3 is a flow diagram of the sinter processing process in conventional coarse aggregate product production, and Fig. 4 is a flowchart of the sintered material processing step in the production of coarse aggregate products according to the present invention, and FIG. 5 is an illustration of the impact force of falling sintered material applied to the inclined plate.
FIG. 6 is a flowchart of the sinter treatment process in the production of coarse aggregate and fine aggregate products according to the present invention. 1...Raw pellets, 2...Bedding, 3.
...Moving grate, 4...Drying/preheating section,
5... Sintered part, 6... Heat retention part, 7...
... Air cooling section, 8 ... Sorting process, 9 ...
...Sintered pellets, 10...Sintering machine, 11...
...Grizzly, 12...Fusion, 13...
...Baby boomers, 14...Remainder, 15...
...Crusher, 16--Sieve, 17--Coarse aggregate product, 18--Powder, 19--Slanted iron plate, 20-- ...Fine aggregate products.

Claims (1)

[Claims] 1 A method of crushing fly ash sintered material obtained by self-combusting green pellets made from fly ash as the main raw material and water as a binder on a moving grate, below the discharge position of the sintering machine. A method for crushing fly ash sintered material, comprising: installing an inclined plate on the inclined plate, dropping the sintered material onto the inclined plate, and then supplying the sintered material to a sizing process.