JP2002249347A - Manufacturing method of granulated blast furnace slag and equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and equipment to manufacture fine aggregate of blast furnace slag for concrete by water granulating, to obtain granulated blast furnace slag having, especially, high rate of coarse grains and high density at the front of furnace. SOLUTION: In water granulating molten blast-furnace slag by cooling water, a gate is installed downstream in a trough to receive granulated slag, where a water reservoir partitioned by the gate is formed by pouring cooling water and leaking it from the lower end of the gate. Molten slag is thrown into the water reservoir and the resulting cooled slag is recovered continuously. By making the gate movable, slag can be granulated by regulating the opening area at the lower end of the gate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing blast furnace slag fine aggregate for concrete by water granulation and an apparatus for producing the same, and more particularly to a method for producing a dense granulated blast furnace slag having a high coarse grain ratio and its production. Related to the device.

[0002]

2. Description of the Related Art Blast furnace slag is used as a raw material for cement, roadbed material,
It is effectively used as aggregate for concrete. The method of treating slag is selected according to these applications, such as a method of directly injecting pressurized water into the molten slag, granulating it, and then crushing it to adjust to the required particle size. There is a method of adjusting the required particle size by crushing after cooling and solidification. The former granulation method is used in the production of cement raw materials and fine aggregate for concrete.

In order to use granulated blast furnace slag as fine aggregate for concrete, an appropriate particle size distribution similar to natural sand is required. However, granulated blast furnace slag is rarely used alone as fine aggregate for concrete, and is often used in the form of a mixture with natural sand. Fine particle sizes are often desired.

[0004] Granulated blast furnace slag is often crushed after granulation in order to improve the grain shape and particle size distribution.
However, if the particle size of the slag after the water granulation is already small, the slag becomes finer when crushed, the sand that can be mixed is limited, and the range of use as fine aggregate is narrowed. Therefore, it is preferable that the particle size of the slag after water granulation be appropriately large in order to improve the particle shape and particle size. As a method for producing coarse-grained hard granulated slag, for example, Japanese Patent Publication No. 6-39340 discloses a method of arbitrarily adjusting the water pressure (water amount) of a nozzle for granulation, driving, upper, and lower in an out-of-pile method. And the unit volume mass (1.45 k
It is disclosed that granulated slag having a large density (g / L or more) and a fine particle size (3.2 FM or more) as a fine aggregate for concrete can be produced. Also, Japanese Patent Application Laid-Open No. H11-2362
No. 55 discloses that water is cooled at a cooling water temperature of 60 to 80 ° C.
Further, a method of granulating water with a ratio of water flow to slag flow (hereinafter referred to as “water / slag ratio”) of 30 or more is disclosed.

[0005] On the other hand, blast furnace slag is easily foamed during granulation and lightened. For fine aggregate for concrete, dense granulated slag is required. For example, JP-A-54-56627
In the publication, hard and almost the same meaning as dense are described as hard.
It is disclosed that the temperature is adjusted to be reduced to 0 ° C. to 850 ° C.
JP-A-55-136151 discloses that pressurized water having a water / slag ratio of 8 to 12 is injected at a water temperature of 70 ° C. or lower. Japanese Patent Application Laid-Open No. 62-113738 discloses injecting pressurized water having a water temperature and a water / slag ratio in a specific area.

[0006]

In the prior art, a method for producing coarse and dense granulated slag is disclosed in Japanese Patent Publication No. 6-39340 and Japanese Patent Application Laid-Open No. 11-236.
No. 255 publication. The granulation method is roughly classified into an out-of-furnace method and a pre-furnace method, both of which are methods of granulating water using pressurized water. The prior publication states that in the out-of-furnace method, the slag temperature is lowered, crystals begin to precipitate, so that it hardens, and because of its high viscosity, it is easy to obtain coarse-grained granules. It is said that fine granules are produced due to low viscosity. In order to obtain fine water granulation in an out-of-furnace method, it is necessary to increase the cooling rate, and the water amount of the granulation nozzle is increased. In addition, the subsequent publication states that when the cooling water temperature becomes high, coarse particles are formed, and in the in-furnace method, the water / slag ratio is set to 30 or more in order to obtain granulated slag having a high specific gravity.

From this, it is considered that it is effective to increase the amount of water for densification in both the pre-furnace system and the out-of-furnace system. On the other hand, increasing the amount of water with respect to the particle size
Although there is no clear relationship in the subsequent gazette, the former gazette shows that the particles are finely divided, and the present inventors have experimentally found that the particles are finely divided. Therefore, increasing the amount of water in the method of granulating using pressurized water,
It is considered to be fine. That is, it seems that the conventional method of granulating with pressurized water has a limit in coarsening.
Therefore, the present invention provides a method for producing dense granulated slag having a high coarse particle ratio and a fine granulated slag by a granulation method different from the conventional one.

[0008]

According to the present invention, there is provided a granulating method for cooling blast furnace molten slag with water, wherein a weir is provided downstream of the granulated slag gutter where the molten slag falls. The molten slag is poured into the water tank to continuously recover the cooled blast furnace slag while maintaining the state where the water tank is formed by injecting the slag cooling water into the part partitioned by the weir while allowing the water to leak from the lower end of the weir. A method for producing granulated blast furnace slag is provided. Using a movable weir, it is also possible to continuously produce granulated blast furnace slag while adjusting the opening area of the lower end of the weir.

Although it is possible to throw molten slag directly into a water tank and granulate it, in the present invention, a method is used in which a slag flux is spread thinly by using a dispersion plate, or a method in which the slag flux is divided and then poured into a water tank. It is recommended to pulverize the water with a slag cooling water flow and then put it into a water tank.

Further, in the present invention, it is recommended that the ratio of the mass flow rate of the injected water to the mass flow rate of the slag be 10 or more and the temperature of the injected water be 60 ° C. or less.

In order to carry out the present invention, an apparatus for cooling and granulating blast furnace molten slag with water is provided with a weir downstream of a granulated slag gutter for charging the molten slag, and the weir forms a water tank for slag cooling water. An apparatus for producing granulated blast furnace slag, which can be formed, has an opening at the lower end of the weir, and has a structure capable of continuously collecting granulated slag together with cooling water is used. It is also possible to use a device having a structure in which a movable mechanism is provided in the weir and the area of the opening between the lower end of the weir and the granulated slag gutter can be arbitrarily adjusted.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors, for the purpose of coarsening granulated blast furnace slag, set the relationship between the water flow rate of blow making water and the coarse particle ratio.
The experiment was conducted simulating the in-furnace method. As a result, it was found that the granulated blast furnace slag becomes coarse when the water flow rate is reduced. Therefore, it was presumed that the maximum coarse grain ratio could be obtained by setting the water flow rate to the minimum value of 0, but slag could not be cooled at the water flow rate of 0 by conventional granulation with pressurized water. Then, as a method that can cool the water flow without hitting the slag, it was found that when molten slag was directly introduced into the water tank, a slag having a higher granularity than granulated slag using pressurized water could be obtained. And, in order to realize this method in front of the blast furnace in which the molten slag flows out continuously, it is possible to continuously collect the granulated slag while maintaining the cooling effect by providing a water tank that continuously replaces the cooling water. The inventors have completed the water granulation method of the present invention having a structure.

That is, the present invention relates to a granulating method for cooling blast furnace molten slag with water, wherein a weir is provided downstream of the granulated slag gutter where the molten slag falls, and slag cooling water is injected into a portion partitioned by the weir. A method of manufacturing granulated blast furnace slag, comprising continuously collecting molten slag into a water tank and continuously collecting cooled blast furnace slag while maintaining a state in which a water tank is formed by allowing water to leak from the lower end of the weir. is there.

FIG. 1 is a schematic side view of an embodiment of the present invention. First, in the conventional water granulation method in front of the furnace, the molten slag 1 falling from the molten slag gutter 5 is granulated with slag cooling water 2 injected from a slag cooling water supply nozzle 6, and the slag and the cooling water are granulated slag. Flow down the gutter 4 and collect. In this case, the molten slag is turned into fine particles by the slag cooling water injected under pressure and cooled. Here, if the water flow rate is reduced, the granulated slag becomes coarse, but in the conventional granulation method, if the water flow rate is extremely reduced, the cooling of the molten slag becomes insufficient. Therefore, in the present invention, the molten slag is charged not into pressurized water but into a water tank to be granulated. The weir 3 is provided downstream of the granulated slag gutter 4 where the molten slag 1 falls, and has a structure capable of holding a water tank water 8 in which slag cooling water is stored. Further, in order to cool the molten slag which is continuously charged, water is leaked from the lower end of the weir 3 so that cooling water can be continuously supplied. Here, the opening area of the lower end of the weir may be constant as long as the granulated slag can be discharged without stagnation. Also, the water level of the water tank is deep enough to allow sufficient cooling, but at least 500 mm at the place where the slag falls
The above is preferred. The molten slag 1 put in the water tank 8
The water is cooled to form granulated slag 9 and discharged together with the cooling water from the lower end of the weir 3. When the conventional slag cooling water supply nozzle 6 is used for the injection of the slag cooling water, the slag cooling water to be injected by installing the slag cooling water flow shielding plate 12 is applied to the slag as shown in the embodiment of FIG. Water can be injected without hitting it, or a dedicated water injection system may be installed.

In the present invention, it is recommended to manufacture granulated slag using a movable weir while adjusting the opening area of the lower end of the weir. When the water injection flow rate is changed according to the change in the slag flow rate in order to smoothly discharge the granulated slag from the lower end of the weir when the slag flow rate changes and to stabilize the quality of the granulated slag It is preferable that the opening area of the lower end of the weir can be adjusted in order to control the drainage amount and water level from the lower end of the weir. On the other hand, when it is desired to carry out the conventional water granulation method, it becomes possible by fully opening the weir. As a movable structure of the weir in the present invention, FIGS. In the embodiment shown in the side view 2 and the front view 3, the opening area of the lower end of the weir is adjusted by moving the weir 3 up and down by the weir driving device 10. In the weir, it is also possible to adjust the water level of the aquarium water 8 by changing the height of the weir. In the embodiment shown in the side view 4 and the front view 5, the weir driving device 10 adjusts the opening area by opening and closing the lower end about the upper end of the weir 3 as a rotation axis.

In the present invention, the molten slag can be directly charged into the water tank to be granulated. However, before the molten slag is charged into the water tank, the slag flux is thinned using the molten slag dispersion plate 7. It is recommended to expand or split. By this method, the surface area of the molten slag is increased, the cooling efficiency of the tank water is increased, and the density of the granulated slag is increased. The surface area can be increased by the dispersion plate only by causing the slag flux to collide with the flat dispersion plate 7 shown in FIG. 1, for example. In order to further increase the cooling efficiency, the dispersion plate 7 having the protrusions 11 shown in FIG. 6 is used. FIG. 7 is a schematic side view showing an embodiment using the dispersing plate. The molten slag 1 collides with the dispersing plate 7 to increase its surface area, and it is sufficient that the molten slag 1 is divided by the projections 11 and falls into the aquarium water. A great cooling effect can be obtained. FIG. 8 is a schematic side view of an embodiment of the present invention according to a different use form of the dispersion plate. In this case, the molten slag can be spread thinner than when the slag flux collides with the dispersing plate, and is divided by the projections 11, so that a more sufficient cooling effect can be obtained.

Further, in the present invention, in addition to using the above-mentioned dispersing plate in order to enhance the cooling efficiency, a slag cooling water supply nozzle used for conventional granulation is used to granulate by a slag cooling water flow and then put into a water tank. It is also possible. In FIG.
1 shows a schematic side view of an embodiment of the present invention using a slag cooling water flow. In the embodiment of FIG. 1, the molten slag 1 is directly or spread thinly by using the dispersion plate 7 and is charged into the water tank 8. In the embodiment of FIG. 9, the molten slag 1 is divided by the slag cooling water 2. To increase the surface area. In this embodiment, the water flow rate is reduced as much as possible within a range where the slag can be divided. The conventional water granulation method requires more water than the slag can be blown off in order to granulate with pressurized water. However, in the present invention, the slag cooling water 2 in this embodiment is slag flow because the water is granulated with aquarium water. It suffices if the bundle can be divided, and the amount of water may be smaller than the conventional water granulation method. On the other hand, if the flow rate of the water to be cooled is too large, the granulated slag becomes fine as in the case of the conventional granulation method, and the effect of adding the slag to the aquarium water of the present invention to make it coarse cannot be obtained. When the water flow rate is reduced by using the slag cooling water supply nozzle 6 of the conventional water granulation apparatus as it is, if the water tank water flow rate is insufficient, increase the number of slag cooling water supply nozzles or install a dedicated water injection system. To secure the aquarium water flow.

In the present invention, the ratio of the mass flow rate of water injected to the mass flow rate of slag is 10 or more. If it is smaller than 10, the cooling is insufficient and the density decreases. Even if the water level changes when the water level changes if the water level changes when the opening area of the lower end of the weir has a constant opening area at the lower end of the weir and the slag flow rate can be sufficiently cooled if the ratio of the water flow rate to the slag mass flow rate is 10 or more. It is. When a movable weir is provided, the water level can be controlled, but the ratio of the water injection mass flow rate to the slag mass flow rate is 10
With the above, granulated slag of higher quality can be obtained. Since the larger the ratio of the mass flow rate of water injected to the mass flow rate of slag is preferable for cooling, the upper limit is not particularly defined. However, as this value increases, the cost of water injection equipment increases, so that 40 is sufficient.

In the present invention, the temperature of the water to be injected is 60 ° C. or less. In the present invention, coarse particles are obtained by pouring molten slag into aquarium water.On the other hand, in order to avoid insufficient cooling due to lack of fine particles and a decrease in density, use of the above-mentioned dispersion plate or water injection amount Is not limited to 10 or more with respect to the slag flow rate, it is also possible to use low-temperature cooling water. Since the lower the temperature, the higher the density, the lower limit is not particularly defined. However, the lower the value, the higher the cost of cooling equipment. Therefore, a low temperature in the range of about room temperature is sufficient. 6
If it is higher than 0 ° C., the effect of densification by water temperature cannot be obtained.

The water granulator of the present invention can be constructed by additionally installing a weir, a molten slag dispersion plate, a weir moving device, and a slag cooling water flow shielding plate in the conventional granulator. When a movable weir is provided, the weir is fully opened and the dispersion plate and the slag cooling water flow shielding plate are retracted, so that it is possible to switch to a water granulation method completely identical to the conventional one at any time.

[0021]

EXAMPLES Table 1 shows examples of the present invention, and Table 2 shows comparative examples of the present invention. FIG. 10 shows the quality change of the slag of the specific examples shown in Tables 1 and 2 after the water granulation and the processing. The comparative example is a production example of granulated slag by a conventional granulation device and a granulation method.

An embodiment of the present invention will be described below with reference to FIG. In order to carry out the present invention, a movable weir 3 was installed in the existing in-furnace granulator. The installation position was about 3000 mm downstream from the position where the molten slag of the granulated slag gutter 4 falls. The height of the vertically movable movable weir shown in FIG. 3 is 1000 mm.
And Before the outflow of the molten slag from the blast furnace begins, the slag cooling water supply nozzle 6 first releases the slag cooling water 2 at a water flow rate of 25 ton / min, and the slag cooling water flow shielding plate 1
2 was inserted to lower the direction of water flow, and discharge into the granulated slag gutter 4 was started. Next, the weir 3 was lowered to start blocking the slag cooling water, and the opening area of the lower end opening of the weir was adjusted to 0.1 square m to form a water tank having a steady water level. When the molten slag 1 started flowing out of the molten slag trough 5, the molten slag dispersion plate 7 was adjusted to a position where it hits the slag, and water granulation was started. After the start of water granulation, the water flow rate was increased stepwise before the ratio of the water flow rate to the slag flow rate became less than 10, for example, in consideration of the increase in the slag flow rate over time that is empirically grasped. The opening area of the weir was also increased accordingly.
During the granulation, the opening area of the weir was adjusted as needed while monitoring the water level of the water tank and the smooth outflow of the granulated slag from the lower end of the weir. For example, when there was a concern that granulated slag would stay in the water tank, the weir was raised, and when the water level was lowered, the water flow rate was increased. In the case where water granulation becomes impossible due to a sudden increase in slag flow rate or the like, the slag cooling water flow shielding plate 12 and the molten slag dispersion plate 7 are immediately evacuated, and the weir 3
Was fully opened to be able to be switched to a normal granulation method.

[0023]

[Table 1]

[0024]

[Table 2]

The water temperatures shown in Tables 1 and 2 are average values of the water temperature fluctuating during granulation. The water / slag ratio is an average of values that change during granulation with a slag cooling water amount (ton / min) with respect to a slag flow rate (ton / min).

In order to use granulated blast furnace slag as fine aggregate for concrete, it is desired to satisfy JIS standards. However, the particle size distribution is rather varied from coarse to fine depending on the particle size of sand to be mixed. Particle size is often desired. Therefore, processing after water granulation is performed until the absolute dry density is at least 2.5 or more of the JIS standard. If the absolute dry density of the granulated slag is already 2.5 or more, improve the grain shape To obtain fine aggregate with as high a coarse grain ratio as possible,
The target was at least a coarse grain ratio of 3 or more. This is because fine aggregate having a high coarse particle ratio can be used by lowering the coarse particle ratio by further crushing when the sand to be mixed is coarse, and is highly useful. As a processing method, a method effective for improving the absolutely dry density and a method effective for improving the grain shape were selectively used and combined, and for example, a normal crusher such as an impact crusher or a cone crusher was used.

The absolute dry density and the coarse particle ratio after granulation and processing were measured in accordance with JIS standards, and were used as a standard for evaluating slag quality.

In Example 1, water was cooled by supplying cooling water having an average water temperature of 80 ° C. at an average water / slag ratio of 12. The weir used a vertical movement type illustrated in FIGS. 2 and 3, and the molten slag dispersion plate used was, for example, a flat plate shape shown in FIG. The coarse-grained ratio of the obtained granulated slag was well above the target, but the processing was performed until the target value became 2.5 or more because the absolutely dry density was low. Was secured. In Comparative Example 8, which will be described later, although the water temperature and the water / slag ratio are low, the coarse grain ratio is low. Therefore, the water granulation method of the present invention provides a granulated slag having a sufficiently high coarse grain ratio. Therefore, a dense slag fine aggregate having a high coarse grain ratio in the quality after processing can be obtained.

Example 2 differs from Example 1 in that the molten slag was divided by a slag cooling water flow without using a slag dispersion plate. The water flow rate was about half that of normal granulation, and a water injection system different from the slag cooling water supply nozzle was installed to secure the water volume. The obtained granulated slag was reduced in coarse particle ratio and improved in density as compared with Example 1 due to granulation with pressurized water. However, the decrease in the coarse particle ratio was small compared to ordinary granulation. When the processing was performed until the absolute dry density reached the target value of 2.5 or more, the coarse grain ratio was able to secure the target of 3 or more.

Example 3 has a higher water / slag ratio than Example 1. Increasing the water / slag ratio in ordinary water granulation decreases the coarse particle ratio, but hardly decreases in the water granulation method of the present invention. On the other hand, the absolute dry density increased due to the improved cooling capacity. The absolute value of the absolute density of the obtained granulated slag is 2.
When processed to 5 or more, a slag fine aggregate having a coarse particle ratio sufficiently satisfying the target of 3 or more was obtained.

In Example 4, water granulation was performed at a water temperature of 60 ° C. or lower with respect to Example 1. Since the obtained granulated slag already exceeded the targets in both the absolutely dry density and the coarse particle ratio, processing was continued to the extent of improving the grain shape, and a dense slag fine aggregate with a high coarse particle ratio was obtained.

Embodiment 5 is an example using a dispersion plate with projections as shown in FIG. Compared with Example 1, the cooling capacity was improved due to the slag dispersion effect of the projections, and the absolutely dry density was increased. Processing was performed until the absolute dry density reached the target value of 2.5 or more, but a slag fine aggregate sufficiently satisfying the target quality was obtained.

Embodiment 6 is an example in which the molten slag is flown on a dispersing plate having protrusions as shown in FIG. Compared with Example 1, the molten slag spreads thinner than the slag flux impinges on the dispersion plate and is divided by the projections 11, whereby a more sufficient cooling effect is obtained, and the absolute dry density of the granulated slag is Improved. Therefore, a smaller processing was performed than in Example 1, and a slag fine aggregate sufficiently satisfying the target quality was obtained.

Example 7 is an example in which a movable movable weir as shown in FIGS. 4 and 5 is used.
Is the same as The granulated slag quality was almost the same as that of Example 1.

Comparative Examples 8 and 9 are examples in which the average water temperature was 80 ° C. and 50 ° C., respectively, by a conventional water granulator. When the water temperature was high, granulated slag having a low density but a relatively high coarse particle ratio was obtained. However, when the processing was performed until the absolute dry density became 2.5 or more, only fine aggregates having a coarse grain ratio less than the target value could be obtained. Conversely, if the water temperature was low, granulated slag with an absolutely dry density of 2.5 or more was obtained, so we stopped the processing to the degree of improving the grain shape, but because the coarse grain ratio was already low, we could only obtain finer fine aggregate. I couldn't. Comparative Example 10 is an example in which the average water temperature was set to 80 ° C. and the water / slag ratio was averaged to 35 to increase the absolute dry density of Comparative Example 8. The absolute dry density of the granulated slag became 2.5 or more, but the coarse particle ratio decreased. Then, when processing was performed to the extent that the grain shape was improved, the fine aggregate had a coarse grain ratio lower than the target. Comparative Example 11 is an example in which water granulation was performed at a relatively low average water temperature of 50 ° C. and a relatively high average water / slag ratio of 35. Both conditions were effective for densification of granulated slag, but they acted in the direction of decreasing the coarse particle rate, and even fine grain size adjustment could produce only fine aggregate with a coarse particle rate below the target. Did not. In the conventional water granulation method, there is a limit in coarsening, and it is difficult to obtain coarse and dense slag fine aggregate as the quality after processing.

[0036]

According to the present invention, it is possible to produce dense granulated slag having a high coarse particle ratio. As a result, it became possible to produce blast furnace slag fine aggregates of various particle sizes from coarse to fine in the subsequent crushing process, it became possible to mix with sand of various particle sizes, and the range of use as fine aggregates was widened . Further, needle-like slag was reduced, the crushing process was light, and the properties of fine aggregate were improved.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention, in which a molten slag is applied to a dispersion plate and then charged into a water tank formed by a weir to granulate the water.

FIG. 2 is a schematic side view showing an embodiment of the water granulator according to the present invention, provided with a mechanism for adjusting the opening area of the lower end of the weir by moving the weir up and down.

FIG. 3 is a schematic front view showing an embodiment of the water granulation apparatus of the present invention provided with a mechanism for adjusting the opening area of the lower end of the weir by moving the weir up and down.

FIG. 4 is a schematic side view showing one embodiment of the water granulator according to the present invention, provided with a mechanism for adjusting the opening area of the lower end of the weir by opening and closing the valve of the weir.

FIG. 5 is a schematic front view showing an embodiment of the water granulation apparatus of the present invention provided with a mechanism for adjusting the opening area of the lower end of the weir by opening and closing the valve of the weir.

FIG. 6 is a perspective view of an example of a dispersion plate provided with protrusions.

FIG. 7 is a diagram illustrating a method of dividing molten slag using the dispersion plate of FIG.
1 is a schematic side view showing an embodiment of the present invention.

FIG. 8 is a schematic side view showing one embodiment of the present invention, in which after the molten slag is divided using the dispersion plate of FIG. 6, the molten slag is poured into aquarium water formed by a movable weir and granulated.

FIG. 9 is a schematic side view showing an embodiment of the present invention, in which molten slag is divided by a water stream jetted from a slag cooling water supply nozzle, and then divided into water tank water formed by a weir to granulate.

FIG. 10 is a diagram showing a change in quality of the slag of the specific examples shown in Tables 1 and 2 after water granulation and the processing thereof.

[Explanation of symbols]

1: molten slag, 2: slag cooling water, 3: weir, 4: granulated slag gutter, 5: molten slag gutter, 6: slag cooling water supply nozzle, 7: molten slag dispersion plate, 8: water tank water, 9: Granulated slag, 10: Weir driving device, 11: Projection for dividing molten slag flux, 12: Slag cooling water flow shielding plate.

Claims (8)

[Claims] In a water granulation method for cooling molten slag of blast furnace with water, a weir is provided downstream of the granulated slag trough where the molten slag falls, and the slag cooling water is poured into a part partitioned by the weir. A method for producing granulated blast furnace slag, wherein molten slag is charged into a water tank and cooled blast furnace slag is continuously collected while maintaining a state in which a water tank is formed by leaking water from a lower end portion. 2. The method for producing granulated blast furnace slag according to claim 1, wherein the opening area of the lower end of the weir is adjusted using a movable weir. 3. The method for producing granulated blast furnace slag according to claim 1, wherein the slag flux is thinly spread or divided using a dispersion plate before the molten slag is charged into the water tank. . 4. The method for producing granulated blast furnace slag according to claim 1, wherein the molten slag is granulated by a slag cooling water stream and then charged into a water tank. 5. The method for producing granulated blast furnace slag according to claim 1, wherein a ratio of a mass flow rate of the injected water to a mass flow rate of the slag is 10 or more. 6. The method for producing granulated blast furnace slag according to claim 1, wherein the temperature of the injected water is 60 ° C. or lower. 7. An apparatus for water-cooling blast furnace molten slag with water, wherein a weir is provided downstream of the granulated slag gutter for charging the molten slag, and the weir can form a slag cooling water tank. An apparatus for producing granulated blast furnace slag, wherein an opening is provided at a lower end of the weir, and the granulated slag is provided with a structure capable of continuously collecting the granulated slag together with cooling water. 8. The weir according to claim 7, wherein a movable mechanism is provided on the weir, and a structure capable of arbitrarily adjusting an area of an opening between a lower end of the weir and the granulated slag gutter is provided. Blast furnace granulated slag manufacturing equipment.