JPS6157553B2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is a method for processing steel slag, which is forcibly pulverized steel slag generated in the steel manufacturing process of a steelworks and effectively used as a substitute for fertilizer, lime, etc. It is related to.

(Conventional technology) Conventionally, steel slag generated from converter furnaces and electric furnaces was
The slag is collected in a slag pot and transported to a processing plant in a slag pot truck, where it is discharged and left in a molten state at a place commonly known as a slag field, where it is further cooled and solidified by water spraying. Afterwards, the large lump is excavated using a bulldozer, etc., and a roughly 3-ton iron ball is hoisted up by a hoist, and the impact of the fall causes it to be coarsely crushed.In the next process, it is crushed and sieved into the desired size. In this process, some steel slags undergo a dusting phenomenon as the slag temperature reaches around 500° C. over time during the cooling process, and most of the slags become powdered.

If such special steel slag is cooled using compressed air as a cooling medium, it will completely turn into powder in about 5 minutes, but a large amount of dust will be scattered, making the environment worse.

In addition, when quenching is performed using water as the cooling medium,
Naturally, it disintegrates into powder, but after powdering, it absorbs a large amount of water and becomes sludge-like, which impedes the recovery of CaO sources in the slag and the effective use of fine powder.

In addition, there were many drawbacks in all cases, such as the need for extensive processing and the use of bulldozers and the like.

Furthermore, Japanese Patent Publication No. 56-24860 discloses a technique in which molten steel slag is charged into a container and forcedly crushed by air in order to recover the heat contained in the slag. However, even if the forced air crushing technology described in this publication is used for the purpose of the present invention, which is to pulverize steel slag and use it as a fertilizer, lime substitute, etc., the particle size can only be crushed to a particle size of about 3 to 1 mm, and even more. It has the disadvantage that it cannot be done quickly and easily because it requires grinding until it becomes solid, and furthermore, the equipment is complicated and wool is generated, so it cannot be used for the purpose of the present invention.

(Problems to be Solved by the Invention) The purpose of the present invention is to provide a method for processing steel slag that can be rapidly crushed into powder of 1 mm or less, can be carried out with a simple device, and does not generate wool. There is a particular thing.

(Means for Solving the Problems) The present invention aims to provide a method for treating steel slag that solves these drawbacks and problems. The steel slag is cooled and solidified in the slag receiving container, and the core inserted into the slag receiving container is taken out to form a coarsely crushed lump. The crushed lumps are put into an inclined rotating cylindrical container into which air is fed, and the air is crushed and cooled in the inclined rotating cylindrical container, and the air crushes the powdered steel slag into the inclined rotating cylindrical container. A method for processing steel slag, characterized by discharging it outside a cylindrical container and separating and collecting it.

Since the slag solidifies at temperatures below 800°C, the slag is poured into a slag receiving container and cooled until the highest temperature in the container reaches 800°C.
The steel slag, which is completely solidified at temperatures below ℃, is crushed into coarse lumps by removing the core. Unsolidified slag is not turned into coarse lumps by such treatment. Further, since steel slag starts to granulate when the temperature is lower than 300°C, dust is generated significantly when it is crushed into coarse lumps and when the coarse crushed lumps are put into an inclined rotating cylindrical container. Therefore, in the present invention, the temperature of the coarsely crushed lumps charged into the inclined rotating cylindrical container is set at 300 to 800°C.
It was limited to ℃.

(Example) A detailed explanation will be given below using examples.

1 to 3 are drawings showing an anchor-shaped core for crushing steel slag in a slag receiving container, and FIG. 4 is a front view showing an example of an apparatus for implementing the steel slag processing method of the present invention.

In the figure, 1 is a slag receiving container, 2 is an anchor-shaped core for crushing steel slag, 3 is a raw material hopper, 4 is a vibration feeder, 5
6 is a lower discharge part of the tilted rotary cylindrical container 5; 8 is an air passage connected to the lower discharge part; 9 is a cyclone; 10 is a bag filter; 11 is the tilted rotary cylindrical container 5 Intake fans 12 and 13 are grizzly belts, 14 and 15 are belt conveyors, and 16 is a heat generator for recovering the heat of the heated air flow in the air passage 8. It is a collection device.

In this example, in order to simplify the coarse crushing process,
A frying pan-shaped slag receiving container 1 for storing steel slag as shown in FIG.
After receiving the slag in a thin layer of about 200 mm to 400 mm, the anchor-shaped core 2 shown in Fig. 3 is inserted into the slag using an overhead crane or the like, and the slag is cooled in a container to a temperature of about 500°C. After cooling, the core 2 is transported to a processing plant, and the core 2 is pulled out using a crane installed in the processing plant.

At that location, if a large amount of metal is mixed into the slag, or if the slag has been cooled to a surface temperature of around 100℃, the slag may be pulled up at the same time as the core 2. It is peeled off by lifting it up and down on the ground two or three times while it is suspended by a crane.

The hot slag crushed in the slag receiving container 1 in this manner is charged into the raw material hopper 3 by tilting the slag receiving container 1 with a crane. A 300 mm square frame-shaped grizzly is provided above the raw material hopper 3, and oversized materials are left on the grizzly, and materials of 300 mm or less are supplied to an inclined rotating cylindrical container 5 by a vibrating feeder 4.
The tilted rotating cylindrical container 5 is rotated by a drive device 6. Therefore, the raw material is scraped up inside the tilted rotating cylindrical container 5 and moved to the lower discharge part 7 while repeatedly falling, and at the same time cooling and dusting phenomena occur. In this process, the steel slag that has become a fine powder is carried by the air sent into the cylinder and guided to the air passage 8 at the end of the tilted rotating cylindrical container 5. It is collected by a filter 10. Also, the parts that do not collapse due to the cooled slag mass are
Grizzles 12 and 13 provided at the lower end of the tilted rotating cylindrical container 5 separate the lumps into fine, medium and large lumps, and they fall onto conveyors 14 and 15 to be conveyed. The released lumps are processed in the next process depending on their purpose, but the powdered steel slag collected by the cyclone 9 and bag filter 10 can be processed by controlling the wind speed so that the size is 2 mm or less. After collection, it is used as fertilizer and road aggregate.

With this implementation device, a 500°C steel slag lump obtained by coarsely crushing stainless steel slag, which is easy to powder, is supplied to the inclined rotating cylindrical container 5, and the steel slag is
When a test was carried out in which the powder was allowed to stay for a minute, the temperature at the lower discharge section 7 was 100°C, and almost 100% of the powder was pulverized to a particle size of 2 mm or less. Moreover,
Particle size of 0.1 mm or less accounted for 70%.

This means that in the case of simple natural cooling, it would take 11 hours to cool down to 100℃, and the pulverization rate was low.
Compared to the experimental value of less than 20%, the powdering rate and cooling rate were dramatically accelerated. A dusting phenomenon is observed even with ordinary steel slag, and although it is not as good as that of special steel slag, which easily dusts, such as stainless steel, it is possible to obtain a considerable dusting rate and cooling rate. For example, in the case of steel slag, which undergoes relatively little pulverization, the temperature at the lower discharge section 7 can be brought to 100°C in 60 minutes, and at that time, the pulverized material with a particle size of 2 mm or less is approximately 40% It became. This is 500℃ with the same steel ratio and natural cooling.
Compared to the fact that it takes 26 hours to reach 100°C and the pulverization rate is only about 30%, this can be said to be a remarkable effect.

The present invention also applies to processes other than the above-mentioned embodiments.
The desired particle size and temperature of the steel slag can be adjusted by changing the amount and flow rate of the cooling air inside the container, and the processing capacity can be adjusted by appropriately changing the diameter and length of the rotating body. can.

As described above, according to the present invention, the cooling rate and powdering rate can be significantly accelerated compared to natural air cooling for both steel slag that can be completely powdered and steel slag that is difficult to powder. It is possible to quickly move on to the next process, and it is also possible to easily collect powdered steel slag of 2 mm or less, preventing fine powder from being brought into the subsequent process. Since there is no need for water sprinkling for powder cooling and there is no need for water sprinkling treatment to prevent dust generation, there is no need for sludge, and there is no need for a subsequent re-recovery process of CaO. An excellent effect can be obtained in that effective utilization becomes easy. Further, the present invention has the advantage that it can be carried out with a simple device and does not generate wool.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the anchor-shaped core inserted into the slag receiving container, Fig. 2 is a side view of the same, Fig. 3 is a perspective view showing the anchor-shaped core, and Fig. 4 is the invention of the present invention. FIG. 2 is a front view showing an example of an implementation device. 1: Slag receiving container, 2: Core, 3: Raw material hopper,
4: Vibration feeder, 5: Cylindrical container, 6: Drive device, 7: Discharge section, 8: Wind path, 9: Cyclone, 1
0: Bug filter, 11: Intake fan, 12,
13: Grizzly.

Claims (1)

[Claims] 1 The slag generated in the steelmaking process is poured into a slag receiving container, and the steel slag cooled and solidified in the slag receiving container is crushed into coarse lumps by taking out the core inserted into the slag receiving container. The crushed lumps, which are at a high temperature of 300 to 800°C, are put into an inclined rotating cylindrical container into which air is fed, and air crushed and cooled in the inclined rotating cylindrical container. A method for processing steel slag, characterized in that the converted steel slag is discharged out of the tilted rotating cylindrical container by the air, and separated and collected.