JP2009227490A - Method of treating slag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently age steel-making slag or the like in a short period of time. <P>SOLUTION: A method of treating slag includes a step A for spraying water to high temperature slag such as the steel-making slag and a step B for aging the slag by bringing steam produced by the water spraying in the step A into contact with the slag cooled by the water spraying, and the step A and the step B using the steam produced in the step A are carried out in places different from each other. The cooling and the aging are efficiently and inexpensively carried out because the aging of the slag is carried out using the steam produced by spraying water to the high temperature slag to utilize the slag latent heat, and the temperature control in the aging is facilitated and the steam-aging is carried out under the most suitable condition because the step of producing the steam by the water spraying and the step of aging using the steam are performed in the places different from each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for efficiently aging steelmaking slag and ore smelting reduction slag generated in a refining process.

In the steelmaking process, since smelting is performed using lime, the generated slag contains CaO. Among them, steelmaking slag with a high basicity (CaO / SiO ₂ ) has a part of the contained CaO as free CaO, and when the slag is used as a roadbed material, the free CaO comes into contact with water. There is a problem of causing hydration expansion. In order to prevent such hydration and expansion of free CaO, conventionally, steelmaking slag generated in the refining process is once solidified and then subjected to aging treatment such as steam aging.
Steam aging to prevent hydration expansion of free CaO is usually performed by blowing steam at 100 ° C. at a normal pressure from the lower layer of slag stacked at a height of about 1 to 2 m and setting the slag temperature to 100 ° C. Do. However, in this system, the aging treatment of steelmaking slag having a basicity of 3 or more takes 3 days or more, and the steam intensity is large.

For such a problem, for example, in Patent Document 1, steelmaking slag is charged in a pressure vessel, pressurized steam is supplied, and a steam atmosphere under a pressure of ² to 5 kgf / cm ² is about 3 hours. A method of aging is shown.
Further, in Patent Document 2, a small piece of hot slag containing free CaO is stored in a sealed container, and water is sprayed on the slag in this container to obtain pressure together with water vapor. A method of aging slag using a high temperature atmosphere is shown.
Patent Document 3 discloses an aging treatment method in which sprinkling or steam is added to a high-temperature steelmaking slag containing free CaO within a slag temperature range of 550 to 100 ° C.
JP-A-5-238786 Japanese Patent Publication No. 58-55093 JP-A-8-119692

However, although the autoclave system disclosed in Patent Document 1 can be processed in a short time, since steam with high pressure is used, energy is required for producing the steam, which is expensive.
On the other hand, since the method of Patent Document 2 performs watering and aging in one sealed container, temperature control is hardly possible, and therefore aging by generated steam cannot be performed at an optimum temperature. Moreover, since the inside of a container becomes high pressure | voltage, it is necessary to use a pressure | voltage resistant container, therefore there exists a problem that workability | operativity is bad and an installation cost and a processing cost also become high.
Moreover, although the method of patent document 3 has added the water spray or water vapor | steam at the temperature of steelmaking slag at 550 to 100 degreeC, the temperature of slag falls by watering, 500 degreeC-which is suitable aging conditions. There is a problem that the time during which the slag temperature can be maintained at 200 ° C. is short and the aging effect cannot be sufficiently exhibited.

  Therefore, the object of the present invention is to solve such problems of the prior art and perform aging treatment of steelmaking slag produced in the refining process and smelting reduction slag produced in the ore smelting reduction treatment in a short time efficiently and at low cost. It is in providing the slag processing method which can be performed.

The gist of the present invention for solving the above problems is as follows.
[1] A method of cooling and aging one or more slags selected from steelmaking slag and ore smelting reduction slag,
A step (A) for sprinkling the hot slag, and a step (B) for aging the slag by bringing the steam generated by the sprinkling in the step (A) into contact with the slag cooled by the sprinkling. A method for treating slag, wherein the step (A) and the step (B) using the steam generated in this step are performed at different locations.
[2] In the processing method of [1], in step (A), water is sprayed on slag having a surface temperature of 700 ° C. or higher to generate steam of 100 ° C. or higher, and in step (B), the surface temperature is 200 ° C. A method for treating slag, wherein the steam is brought into contact with slag of ˜500 ° C. to perform an aging treatment.

[3] The slag processing method according to the above [1] or [2], wherein the slag is collapsed into granules by the aging process of step (B) to form granular slag.
[4] In the processing method according to any one of [1] to [3] above, the processing container (X1) and (X2) are used to move the slag in the order of the processing container (X1) and the processing container (X2). A processing method for sequentially performing the step (A) in the container (X1) and the step (B) in the processing container (X2),
Step (B) for introducing the steam generated in step (A) for the slag of the subsequent charge in the processing vessel (X1) into the processing vessel (X2) and for the slag of the preceding charge in the processing vessel (X2) A method for processing slag, characterized by being used in the above.
[5] In the processing method according to any one of [1] to [3], the processing containers (Xa) and (Xb) are used, and the process (A) and the process are performed in the processing containers (Xa) and (Xb), respectively. (B) is performed sequentially, and at the same time, step (A) is performed in one processing container (Xa) or (Xb), and step (B) is performed in the other processing container (Xb) or (Xa). ,
A method for treating slag, characterized by introducing the steam generated in step (A) in one processing vessel (Xa) or (Xb) into the other processing vessel (Xb) or (Xa).

[6] In the processing method according to any one of [1] to [3], the step (A) and the step (B) are sequentially performed on the slag being transferred in the processing container, and generated in the step (A). A method for treating slag, characterized in that the step (B) is performed by bringing steam into contact with the slag on the downstream side in the slag transfer direction from the watering position in the step (A).
[7] In the processing method of [6] above, a slag loading portion is provided on one end side, and a slag discharge portion is provided on the other end side, and is inclined downward from one end side toward the other end side, with the cylinder axis as the center A method for treating slag, comprising using a rotating cylindrical processing container, and sequentially performing the step (A) and the step (B) while transferring the slag in the longitudinal direction in the cylindrical processing container.
[8] A method for treating slag according to any one of the above [1] to [7], wherein the steam used in step (B) is recovered as a heat source fluid.

[9] The molten slag is cooled by bringing it into contact with a rotating cooling drum and discharged as high-temperature slag in the form of a plate, column, or strip, and the molten slag is subjected to cooling treatment. A method for processing slag, comprising performing any one of the processes [1] to [8] on a high-temperature slag.
[10] The molten slag is cooled while being rolled with a pair of rotating cooling drums, and discharged as high-temperature slag in the form of a plate, column, or strip, and the molten slag is cooled and cooled. A method for treating slag, comprising performing any one of the above-described [1] to [8] on a high-temperature slag after treatment.
[11] The slag characterized in that in the treatment method of [9] or [10], the cooling drum is a water-cooling type, and a part of the cooling water that has passed through the cooling drum is used for water spraying in step (A). Processing method.

  According to the slag treatment method of the present invention, water is sprinkled on high-temperature steelmaking slag and ore smelting reduction slag, and slag aging is performed by steam generated using slag sensible heat. Cooling and aging treatment can be performed efficiently and at low cost. In addition, since the step of generating steam by watering and the step of aging treatment using this steam are performed at different locations, the temperature management of the aging treatment is easy, and the steam aging treatment can be performed under optimum temperature conditions. For this reason, slag can be particularly efficiently aged.

  The slag treatment method of the present invention is a method of cooling and aging one or more slags selected from steelmaking slag and ore smelting reduction slag, and includes water spraying in process A and water spraying in process A. The process B has a process B for aging the slag by bringing the steam generated by the process into contact with the slag cooled by watering, and the process A and the process B using the steam generated in this process are performed at different locations. is there. Examples of the method of the present invention include the following.

(A) Step A and Step B are sequentially performed on the slag being transferred in the processing container, and the steam generated in Step A is brought into contact with the slag on the downstream side in the slag transfer direction from the sprinkling position in Step A. The processing method which performs the process B by.
(B) A processing method in which processing containers X1 and X2 are used and slag is moved in order of processing container X1 and processing container X2, and step A is sequentially performed in processing container X1 and processing container X2. A processing method in which the steam generated in the process A for the slag of the subsequent charge in the container X1 is introduced into the processing container X2 and used in the process B for the slag of the preceding charge in the processing container X2.
(C) Using the processing containers Xa and Xb, the process A and the process B are sequentially performed in the processing containers Xa and Xb, and the process A is performed in one processing container Xa or Xb at the same time. Alternatively, a process method in which the process B is performed in Xa, and the steam generated in the process A in one process container Xa or Xb is introduced into the other process container Xb or Xa.
In the above processing method (A), an appropriate slag transfer means in the processing container can be used. For example, a mechanism that rotates and transfers a cylinder inclined by a rotary kiln system, a conveyor mechanism, or the like can be adopted.

Steelmaking slag and ore smelting reduction slag to be treated are slag in a high temperature state that has sensible heat generated in the refining process or ore smelting reduction process, including molten slag, semi-molten slag, partially solidified slag , Either semi-solidified slag or solidified slag. Here, the partially solidified slag is a slag in which only the surface layer is solidified and the inside is in a molten state.
Examples of steelmaking slag include converter decarburization slag, hot metal pretreatment slag (for example, dephosphorization slag, desiliconization slag, desulfurization slag, etc.), electric furnace slag, cast slag, and the like. In particular, since the free CaO phase is present in steelmaking slag having a slag basicity [mass ratio:% CaO /% SiO ₂ ]: about 3 to 5, application of the method of the present invention is particularly effective. is there.
Examples of the ore melting reduction slag include ore melting reduction slag such as iron ore and chromium ore. The ore smelting reduction slag may contain a relatively large amount of free MgO phase, and this free MgO phase may cause the same problem as that described above with the free CaO phase. Is effective.

Hereinafter, an embodiment of the present invention will be described by taking an example of processing steelmaking slag.
The slag processing (steps A and B) of the present invention is performed in a closed space such as in a processing container. When using a processing container, there is no special restriction | limiting in the form and structure of a container, but it needs to have airtightness of the grade which can hold | maintain a vapor | steam.
In the present invention, in step A, water is sprinkled on the high-temperature steelmaking slag to cool the slag and generate water vapor. The watering method is arbitrary, and for example, a method of spraying in a shower form or spray form from a perforated nozzle or a method of spraying in a mist state can be applied. The amount of water sprayed into the slag is suitable for aging in the process B if the temperature and amount of the charged slag, the amount of steam to be generated, and the like are controlled so that the slag surface temperature in the container is about 500 ° C. It becomes a condition.
Next, in the process B, the steam generated by the water spraying in the process A is brought into contact with the steelmaking slag cooled by the water spraying, and the aging treatment is performed. In the present invention, the steam generated in the process A and this process is used. Step B is performed at a different location. Thereby, temperature control of steelmaking slag can be performed appropriately and an aging process can be performed at the optimal temperature. Further, in the process B, the steelmaking slag is cooled by the steam generated in the process A, and the temperature of the steam is increased by the heat deprived from the steelmaking slag during the process B, and can be recovered as superheated steam.

In the present invention, (a) performing aging treatment with steam generated using slag sensible heat generated in the refining process (that is, performing steam aging without using an external thermal energy source), (B) Since the process of generating steam by sprinkling and the process of aging using this steam are performed at different locations, the temperature management of the aging process is easy, and the steam aging process can be performed under optimum temperature conditions Thus, the steelmaking slag can be efficiently cooled and aged at a low cost in a short time.
In addition, since the slag collapses into particles due to expansion during the hydration reaction by the aging treatment and becomes finer, the crushing step after the aging treatment can be reduced or omitted. Therefore, by appropriately selecting the aging treatment conditions such as the treatment time, the steelmaking slag can be collapsed into a granular shape, and the granular slag can be obtained without going through a crushing step.

In the present invention, in the slag high temperature range that is ineffective for the hydration reaction (aging process), a large amount of steam is generated by watering as much as possible, and the slag temperature is lowered to the optimum temperature range for the hydration reaction (aging process). Occasionally, it is preferable to perform steps A and B under the following temperature conditions so that the generated steam is brought into contact with the slag.
That is, in step A, it is preferable to sprinkle steelmaking slag having a surface temperature of 700 ° C. or higher, more preferably 900 ° C. or higher to generate steam of 100 ° C. or higher, more preferably 150 ° C. or higher. Moreover, in process B, it is preferable to perform an aging process by making it contact with a steam, while steelmaking slag has the surface temperature of 200-500 degreeC, More preferably, it is 400-500 degreeC. By adopting the temperature conditions as described above, particularly efficient and economical slag processing is possible.

By spraying steelmaking slag having a surface temperature of 700 ° C. or higher, preferably 900 ° C. or higher, high-temperature steam of 100 ° C. or higher can be stably generated. Moreover, the one where the temperature of the steelmaking slag at the time of contact with the steam is higher to some extent can perform an efficient aging treatment. For this reason, the steelmaking slag is brought into contact with the steam while having a surface temperature of 200 to 500 ° C. Processing efficiency can be improved by performing an aging process.
FIG. 1 shows the surface temperature of slag when flowing steam in a furnace at room temperature to 700 ° C., and the effect of suppressing expansion due to steam aging (steam aging for 0.5 hour, 2 hours, The relationship with the expansion rate of slag after 24 hours was investigated. The expansion rate of slag was measured by the water immersion expansion test method for steel slag described in JIS A 5015 “Steel Slag for Roads” Appendix 2.

The free CaO phase contained in the steelmaking slag reacts with water (steam) in the aging process to become Ca (OH) ₂ , but this reaction is a temperature until the slag surface temperature is about 400 ° C. as shown in FIG. The higher the value, the faster the reaction speed and the aging progresses. However, when the temperature is higher than this, Ca (OH) ₂ is decomposed to CaO and H ₂ O, so that the hydration reaction of CaO starts to be slow at 400 ° C. or more, particularly above 500 ° C. When the temperature exceeds 600 ° C., the hydration reaction does not occur. Therefore, in order to promote the hydration reaction of CaO in contact with steam, a slag surface temperature of about 200 to 500 ° C. is suitable.
Therefore, the slag surface temperature that is ineffective for the hydration reaction is sprinkled within the highest possible temperature of 700 ° C. or more to generate steam, and the slag surface temperature is 200 to 500 ° C. to bring the slag and steam into contact with each other to conduct the hydration reaction The promotion method uses the heat held by the slag most efficiently.
Moreover, from the point of generating high-temperature steam, it is preferable to complete the cooling of the slag by watering at a slag surface temperature of 500 ° C. or higher.
The hydration reaction promoting effect as described above is effective not only for the free CaO phase but also for the free MgO phase.

In the method of the present invention, it is preferable to recover the steam in the processing vessel as a heat source fluid, whereby slag sensible heat can be efficiently recovered, and the energy efficiency of the steel works can be improved and the amount of CO ₂ gas generated can be reduced. Can do.
The steam taken out from the processing container can be used as an appropriate heat source fluid, for example, a heat source for drying / preheating of raw materials, fuel, auxiliary materials, waste, etc., a heat source for water heaters, and a supply to a heat storage material. It can be used as a heat source, a regeneration heat source for an adsorption refrigerator, an adsorbent regeneration heat source for carbon dioxide and other adsorption devices, and the like.

Next, specific modes of the present invention exemplified as (A) to (C) described above will be described.
FIG. 2 relates to the above-described form (a), and schematically shows an embodiment of the method of the present invention using a rotating cylindrical processing container (rotating drum) as a processing container.
The cylindrical processing container 1 includes a slag charging part 2 on one end side, a slag extraction part 3 and a steam extraction part 4 on the other end side, and is inclined downward from one end side toward the other end side, It can be rotated around the center. The basic structure of the cylindrical processing container 1 is the same as that of a so-called rotor kiln, and the material (slag) charged into the cylindrical processing container 1 is rotated by a cylindrical processing container inclined in the longitudinal direction. By doing so, it is sequentially transferred in the longitudinal direction of the container. A water spray mechanism 5 is installed in the upstream portion of the cylindrical processing container 1 in the slag transfer direction.

  In addition, the slag treatment by the cylindrical treatment container 1 is performed by (a) a method of loading and unloading steelmaking slag in a batch manner, and (b) loading and unloading of steelmaking slag at appropriate time intervals. (C) A method for continuously charging steelmaking slag, (c) A method for continuously charging steelmaking slag, (c) A method for continuously charging steelmaking slag, and (c) A method for continuously charging steelmaking slag. Either a method of taking out steelmaking slag at an appropriate time interval or (e) a method of continuously inserting and taking out steelmaking slag may be used. Among these, the methods other than (a) are used for the aging treatment (hydration reaction of free CaO) of the steelmaking slag charged before the steam generated by sprinkling the steelmaking slag charged later. .

  In the present embodiment, high-temperature steelmaking slag Sa is charged into the container from the slag charging portion 2 of the rotating cylindrical processing container 1. The steelmaking slag Sa may be any of molten slag, partially solidified slag, and solidified slag as long as it is a high-temperature slag that retains sensible heat generated in the refining process. Since the cylindrical processing container 1 is rotating, the steelmaking slag Sa charged is prevented from adhering to the inner wall of the container. The rotation speed of the cylindrical processing container 1 is arbitrary, and may be, for example, about 2 to 5 rotations / minute.

The hot steelmaking slag Sa charged in the cylindrical processing container 1 is sprinkled with water from the watering mechanism 5, and steam is generated by the watering. This is step A of the present invention. Steam generated by watering flows downstream in the slag transfer direction in the processing container, while steelmaking slag Sa cooled and cooled to a certain temperature by watering sequentially moves in the longitudinal direction of the container. The steam flowing in the same direction comes into contact with the moving steelmaking slag, and heat exchange is performed between the two, and an aging treatment is performed by which the free CaO in the slag causes a hydration reaction. This is step B of the present invention. At this time, since the slag is agitated by the rotation of the cylindrical processing container, the contact with the steam is promoted, and the hydration reaction of free CaO occurs efficiently. In the embodiment described in this specification including this embodiment, the slag in the process A (before the start of water spray cooling, during the water spray cooling, and after water spray cooling) is referred to as “slag Sa”, and the process B (of the aging treatment). The slag at the beginning, during the aging process, and after the aging process) is referred to as “slag Sb”.
In addition, slag breaks (collapses) due to volume expansion (volume expansion due to a decrease in density) during hydration reaction, and new free CaO is exposed to the slag surface and comes into contact with steam, further hydration reaction proceeds, slag Gradually breaks down and becomes finer. Thus, since the steelmaking slag Sb is gradually refined by the aging treatment, the steelmaking slag Sb is sufficiently finely adjusted by appropriately adjusting the residence time (aging treatment time) of the steelmaking slag in the treatment container after watering. The crushing process after granulating and aging treatment can be omitted.

The slag Sb that has been subjected to the aging process in the cylindrical processing container 1 is taken out from the slag take-out part 3, and the steam is taken out from the steam take-out part 4 and used as a heat source fluid as necessary.
Also in this embodiment, for the reasons described above, the surface temperature is 700 ° C. or higher, preferably 900 ° C. or higher, and water is sprayed to generate steam of 100 ° C. or higher, preferably 150 ° C. or higher. While the steelmaking slag has a surface temperature of 200 to 500 ° C., preferably 400 to 500 ° C., it is preferable to perform the aging treatment by contacting with steam.

FIG. 3 shows a more specific embodiment using the cylindrical processing container 1 (rotary drum). In this embodiment, a hopper portion 6 for batch charging is provided on the front surface of the slag charging portion 2 of the cylindrical processing container 1. A lid 600 is provided on the inlet side of the hopper portion 6, and an open / close gate 610 is provided on the outlet side communicating with the slag loading portion 2. The slag extraction part 3 is provided with an open / close gate 300, and the steam extraction part 4 is connected with a steam pipe 400. Further, a watering pipe 500 is led into the container from the container end on the slag charging part 2 side and connected to the watering mechanism 5.
In such an embodiment, after charging a predetermined amount of steelmaking slag Sa into the hopper 6, the lid 600 of the hopper 6 is closed, then the open / close gate 610 is opened, and the total amount of steelmaking slag Sa in the hopper 6 is filled. Then, it is charged into the processing container from the slag charging part 2. The steelmaking slag Sa charged is sprinkled from the sprinkling mechanism 5 and subjected to the aging treatment as described above by the generated steam. Steelmaking slag Sb and steam that have been subjected to the aging treatment are taken out from the slag take-out part 3 and the steam take-out part 4, respectively.

In this embodiment, the exhaust port 401 of the steam extraction part 4 is provided near the axial center in the processing container radial direction, and the slag Sb in the processing container always covers the exhaust port 401. Thereby, since the vapor | steam in a processing container passes through the slag Sb, and is discharged | emitted from the exhaust port 401, vapor | steam temperature can be raised by heat exchange with slag, and higher temperature vapor | steam can be collect | recovered. The exhaust port 401 is provided with a net (not shown) for preventing slag intrusion.
In the slag treatment method of the form (a) as described above, the water of CaO can be obtained in a short time by continuously subjecting the slag being transferred in the treatment vessel to water aging and the aging treatment by the steam generated thereby. The aging can be terminated by advancing the sum reaction.

FIG. 4 relates to the form (b) described above, and schematically shows an embodiment of the method of the present invention.
In this slag treatment mode, the processing vessel X1 and the processing vessel X2 are used, and the steelmaking slag is moved in the order of the processing vessel X1 and the processing vessel X2, and the process A is sequentially performed in the processing vessel X1 and the processing vessel X2. Do. Then, the steam generated in the process A for the steelmaking slag of the subsequent charge in the processing container X1 is introduced into the processing container X2 and used in the process B for the steelmaking slag of the preceding charge in the processing container X2.

  In the present embodiment, the processing container X1 is formed of a cylindrical rotating drum type container similar to the cylindrical processing container of FIG. The processing container X1 includes a slag loading part 2f on one end side, a slag extraction part 3f and a steam extraction part 4f on the other end side, and is inclined downward from one end side toward the other end side, and is centered on the cylinder axis. Can be rotated. The basic structure of the processing container X1 is the same as the structure of a so-called rotor kiln, and the material (slag) charged in the processing container X1 is rotated in the longitudinal direction by rotating the processing container inclined in the longitudinal direction. Sequentially transferred in the direction. A watering mechanism 5f is installed in the upstream portion in the slag transfer direction in the processing container X1.

An opening / closing gate 610f is provided in the slag charging portion 2f, an opening / closing gate 300f is provided in the slag extraction portion 3f, and one end of a steam pipe 7 is connected to the steam extraction portion 4f. Further, a watering pipe 500f is led into the container from the container end on the slag charging part 2f side, and is connected to the watering mechanism 5f.
In the present embodiment, the processing container X2 is a tank-type container, and the slag can be taken in and out by opening the upper lid 20. A steam inlet 8 is provided at the bottom of the container, and the other end of the steam pipe 7 is connected to the steam inlet 8. Further, a steam take-out section 9 is provided at the upper part of the processing container X2, and a steam pipe 90 is connected to the steam take-out section 9.

  In addition, processing of slag by processing container X1 is (a) a method of loading and unloading steelmaking slag in a batch system, and (b) loading and unloading of steelmaking slag at appropriate time intervals. A method for always retaining slag, (c) a method for continuously charging steelmaking slag at an appropriate time interval, a method for continuously removing steelmaking slag, and (d) a method for continuously charging steelmaking slag, Either a method of taking out steelmaking slag at an appropriate time interval or (e) a method of continuously inserting and taking out steelmaking slag may be used.

In the present embodiment, high-temperature steelmaking slag Sa is charged into the container from the slag charging part 2f of the rotating processing container X1. The steelmaking slag Sa may be any of molten slag, partially solidified slag, and solidified slag as long as it is a high-temperature slag that retains sensible heat generated in the refining process. Since the processing container X1 is rotating, the steelmaking slag Sa charged is prevented from adhering to the inner wall of the container. The rotation speed of the processing container X1 is arbitrary, and may be, for example, about 2 to 5 rotations / minute.
The hot steelmaking slag Sa charged in the processing vessel X1 is sprinkled from the watering mechanism 5f, and steam is generated by the watering. This is step A of the present invention. The steam generated by the sprinkling is taken out from the steam outlet 4f and sent to the processing container X2 through the steam pipe 7.

The processing vessel X2 is filled with steel slag with a pre-charge that has already been sprinkled and cooled in the process A in the processing vessel X1, and in this processing vessel X2, the subsequent charging of steel in the processing vessel X1 is made. The steam generated in the process A for the slag is introduced through the steam pipe 7 as described above, and an aging process using this steam is performed. This is step B of the present invention.
The steam introduced from the steam introduction part 8 into the processing container X2 passes through the steelmaking slag Sb, is discharged from the steam extraction part 9 to the steam pipe 90, and is used as a heat source fluid as necessary. Also in this embodiment, the steam temperature can be increased by heat exchange with the slag, and higher temperature steam can be recovered.

The steelmaking slag Sb that has finished the aging process in the processing container X2 is taken out of the container. On the other hand, the post-charge steelmaking slag Sa that has been sprayed and cooled in the processing container X1 is taken out from the slag extraction part 3f, and transferred to and charged into the processing container X2 by an appropriate transfer / loading means. Charged steelmaking slag Sa is charged into the processing container X1, and the processing (steps A and B) as described above is repeated in the processing containers X1 and X2.
Note that the aging process principle and effects in the processing container X2, the preferable temperature conditions in the steps A and B, and the like are the same as those described in the embodiment of FIGS.

FIG. 5 relates to the above-described form (c), and schematically shows an embodiment of the method of the present invention.
In this slag processing mode, the processing containers Xa and Xb are used, and the process A and the process B are sequentially performed in the processing containers Xa and Xb, and the process A is performed in one processing container Xa or Xb at the same time. The process B is performed in the processing container Xb or Xa. Then, the steam generated in step A in one processing container Xa or Xb is introduced into the other processing container Xb or Xa.

  In this embodiment, each processing container Xa, Xb is constituted by a tank-type container, and the slag can be taken in and out by opening the upper lids 20a, 20b. Sprinkling nozzles 21a and 21b for spraying water in the containers are provided above the processing containers Xa and Xb. In addition, steam introducing portions 22a and 22b are provided at the bottoms of the processing containers Xa and Xb, and steam extracting portions 23a and 23b are provided at the top. Each end of the steam pipe 24 is connected to the steam introduction part 22a of the processing container Xa and the steam introduction part 22b of the processing container Xb, and is in communication with the steam pipe 24. Further, steam pipes 27a and 27b are connected to the steam take-out portions 23a and 23b, respectively, and on-off valves V1 and V4 are provided on the steam pipes 27a and 27b, respectively.

Each end of the steam pipe 25 is respectively connected to a pipe part of the steam pipe 27a between the on-off valve V1 and the steam take-out part 23a and a pipe part of the steam pipe 27b between the on-off valve V4 and the steam take-out part 23b. Connected and connecting both pipes. Furthermore, each end of the steam pipe 26 is connected to the middle of the steam pipe 24 and the middle of the steam pipe 25 to connect the both steam pipes 24 and 25.
In the steam pipe 25, on-off valves V 2 and V 5 are respectively provided in the pipe parts 25 a and 25 b on both sides of the connection part of the steam pipe 26, and in the steam pipe 24, the pipe parts 24 a on both sides of the connection part of the steam pipe 26 are provided. On-off valves V3 and V6 are provided at 24b, respectively.

  In this embodiment, the steelmaking slag Sa is charged into the processing containers Xa and Xb, and the process A and the process B are sequentially performed in the processing containers Xa and Xb. The process A is performed in the container Xa or Xb, and the process B is performed in the other processing container Xb or Xa. The steelmaking slag Sa charged into the processing containers Xa and Xb may be any of molten slag, partially solidified slag, and solidified slag as long as it is a high-temperature slag that retains sensible heat generated in the refining process. Good.

  In the state shown in FIG. 5, watering (process A) is performed on the steel slag Sa from the watering nozzle 21a in the processing container Xa. On the other hand, steam generated in the process A in the processing container Xa is introduced into the processing container Xb, and an aging process (process B) of the steelmaking slag Sb is performed. At this time, the on-off valves V1, V5, V3 are closed and the on-off valves V2, V6, V4 are opened, and the steam generated in the processing container Xa is the steam pipe 27a, the pipe portion 25a of the steam pipe 25, and the steam pipe 26. The steam pipe 24 is introduced into the processing container Xb from the steam introduction part 22b via the pipe part 24b. This steam passes through the slag and is discharged from the steam outlet 23b to the steam pipe 27b and used as a heat source fluid as necessary. Also in this embodiment, the steam temperature can be increased by heat exchange with the slag, and higher temperature steam can be recovered.

When the process A in the processing container Xa and the process B in the processing container Xb are completed, the steelmaking slag Sb in the processing container Xb is discharged, and a new high-temperature steelmaking slag Sa is charged into the container. In the processing container Xb, water spraying (process A) is performed on the steelmaking slag Sa from the water spray nozzle 21b, and in the processing container Xa, the steam generated in the process A in the processing container Xb is introduced, and the steelmaking slag Sb An aging process (process B) is performed. At this time, the on-off valves V4, V2, V6 are closed, the on-off valves V5, V3, V1 are opened, and the steam generated in the processing vessel Xb is the steam pipe 27b, the pipe portion 25b of the steam pipe 25, and the steam pipe 26. The steam pipe 24 is introduced into the processing container Xa from the steam introduction part 22a via the pipe part 24a. This steam passes through the slag Sb and is discharged from the steam outlet 23a to the steam pipe 27a, and is used as a heat source fluid as necessary.
By repeating the above, steps A and B of the present invention can be performed without moving the steelmaking slag.
In addition, the principle and effect of the aging process in each processing container, preferable temperature conditions in the steps A and B, and the like are the same as the contents described in the embodiments of FIGS.

The slag treated by the method of the present invention can be used for appropriate applications. For example, those that are sufficiently finely divided by an aging treatment can be used for aggregates such as hydrated cured products and cement admixtures. .
In the method of the present invention, it is possible to treat the molten slag as it is, but in terms of handling of the slag and prevention of steam explosion, the molten slag is cooled to some extent, and a high-temperature slag in a non-molten state is obtained. It may be advantageous to perform the slag treatment as described above.
In order to convert the molten slag into a non-molten high temperature slag, generally used methods include discharging the molten slag into a slag processing yard and cooling it, and cooling the molten slag by putting it in a pan. In these cases, the surface of the slag is solidified to some extent, it is still broken by a shovel at a high temperature (preferably the surface temperature is 700 ° C. or higher), and charged into a processing vessel for carrying out the present invention.

On the other hand, when the molten slag is made into a non-molten high-temperature slag, the method (i) or (ii) below can be used to efficiently cool the molten slag and to make it easy to handle. Since it can be set as a piece-like high temperature slag, it is especially preferable.
(I) The molten steel slag is cooled by contacting the cooled slag with a rotating cooling drum and discharging the molten slag as a plate-like, columnar or strip-like high-temperature slag.
(Ii) The molten steelmaking slag is cooled by using a slag cooling processing device that cools the molten slag while rolling it with a pair of rotating cooling drums and discharges the molten slag as a plate-like, columnar, or strip-like high-temperature slag.
And the slag process by this invention method as mentioned above is performed with respect to the high temperature steelmaking slag cooled by the method of (i) or (ii) as described above. The methods (i) and (ii) are also effective when obtaining a predetermined particle size depending on the purpose and application of the slag.

First, the slag cooling method (i) will be described.
In this cooling processing method, for example, as shown in FIG. 6 (a front view schematically showing the apparatus), a pair of cooling drums 10a having a rotation direction in which the outer peripheral portions facing each other rotate in parallel in the horizontal direction rotate upward. , 10b is used.
The cooling drums 10a and 10b are rotationally driven in the rotational direction by a driving device (not shown). Inside the cooling drums 10a and 10b, an internal cooling mechanism (not shown) having a flow path for passing the refrigerant is provided, and a refrigerant supply section and a refrigerant discharge section for the internal cooling mechanism are provided at each end of the drum shaft. Are provided respectively. Note that water (cooling water) is generally used as the refrigerant, but other fluids (liquid or gas) may be used.

In this method, molten slag S is supplied from above (in the figure, 11 is a slag pan, 12 is a slag tub) between the upper outer peripheral surfaces of the pair of cooling drums 10a and 10b, and a slag liquid reservoir g is formed. The molten slag S is taken out from the slag liquid reservoir g by adhering to the surfaces of the rotating cooling drums 10a and 10b, and the molten slag S adheres to the cooling drum surface and is in an appropriate solidified state (for example, semi-solidified). After cooling to a state or a state in which only the surface layer is solidified), it is separated from the surface of the cooling drum by its own weight at a predetermined drum rotation position, and recovered as a high-temperature slag Sx such as a plate shape. The slag Sx peeled from the cooling drum surface is transported by the transport conveyor 13 and accommodated in the slag bucket 14.
When the slag Sx is paid out from the conveyor 13 to the slag bucket 14 or the like, the slag Sx may be roughly crushed by an appropriate means as necessary.

  Moreover, you may use the cooling processing apparatus which has a weir above the cooling drums 10a and 10b as shown in FIG. 7 (front view which shows an apparatus typically). In this cooling processing apparatus, weirs 16 including cooling drums 15a and 15b are provided above the pair of cooling drums 10a and 10b, respectively, and between the upper outer peripheral surfaces of the pair of cooling drums 10a and 10b and a pair of cooling drums. A slag liquid reservoir G is formed between 15a and 15b (weir 16). The cooling drums 15a and 15b have a rotational direction in which the lower outer peripheral surface rotates in the direction of the anti-slag liquid reservoir G. Between each of the cooling drums 15a and 15b and the cooling drums 10a and 10b, there is an opening 18 through which the molten slag S in the slag liquid reservoir portion G is pushed out. High temperature slag Sx is obtained.

On both end sides in the width direction of the cooling drums 10a and 10b and the cooling drums 15a and 15b (weirs 16), weir plates 17 for closing both ends of the slag liquid reservoir G are provided on the cooling drums 10a and 10b and the cooling drum 15a. , 15b so as to be in contact with the end face. This dam plate 17 is supported by the apparatus main body (base | substrate) via a suitable support member.
The weir body 16 may be composed of a fixed wall body instead of the cooling drums 15a and 15b.

  In such a cooling processing apparatus, the slag liquid reservoir is formed by forming the slag liquid reservoir G between the upper outer peripheral surfaces of the pair of cooling drums 10a and 10b and between the pair of cooling drums 15a and 15b (weirs 16). Since the residence time of the molten slag in the part G can be lengthened, the cooling of the molten slag can be effectively promoted, and the appropriately cooled slag can be pushed out from the opening 18. Further, as in the present embodiment, the weir 16 is constituted by the cooling drums 15a and 15b having a rotation direction in which the lower outer peripheral surface rotates in the direction of the anti-slag liquid reservoir G, thereby more effectively cooling the molten slag. The thick slag solidified body can be obtained more stably.

  Further, in the cooling processing apparatus having the cooling drums 15a and 15b (weirs 16) as shown in FIG. 7, grooves are provided on the outer peripheral surfaces of the cooling drums 15a and 15b to obtain a columnar or strip-like (lumped) high-temperature slag. You may be made to do. 8 and 9 (a front view and a side view schematically showing a part of the apparatus) show an example of such a cooling processing apparatus, and a plurality of annular grooves 150 are formed on the outer peripheral surfaces of the cooling drums 15a and 15b. Are formed at intervals in the drum longitudinal direction, and the bottom surfaces of the annular grooves 150 are configured to be uneven (gear-like) in the drum circumferential direction, and the outer peripheral surfaces of the cooling drums 15a and 15b are the outer peripheral surfaces of the cooling drums 10a and 10b. The hole-shaped opening 18 is formed by the annular groove 150. In this embodiment, the opening 18 is intermittently enlarged by the recess on the bottom surface of the annular groove 150.

In the present embodiment, the slag Sx is extruded from the plurality of hole-shaped openings 18 formed by the annular groove 150. The slag Sx is pushed out in a shape such that the mass portions b are connected in a bead shape because the openings 18 are intermittently enlarged by the concave portions on the bottom surface of the annular groove 150. The slag Sx having such a shape is separated from the cooling drums 10a and 10b and then separated into a lump by its own weight or easily separated into a lump by a small external force.
In FIG. 9, the unevenness formed in the circumferential direction on the bottom surface of the annular groove 150 is omitted, but the position of the convex portion on the bottom surface is indicated by a virtual line.

  Further, as shown in FIG. 10 (a front view schematically showing the apparatus), the cooling processing apparatus may be provided with a single cooling drum. The cooling processing apparatus includes a cooling drum 10 and a flange 19 arranged on one side in the cooling drum radial direction. The flange 19 is provided such that the tip thereof is in contact with or close to the drum surface 100 of the cooling drum 10, and the tip portion of the flange 19 and the drum surface 100 form a slag liquid reservoir G. With this rotation, the molten slag S in the slag liquid reservoir G is attached to the drum surface 100 and taken out. In order to form the slag liquid reservoir G, the tip of the ridge 19 has a tray-like shape bent or curved upward (horizontal), and the tip of the ridge 19 is in contact with or close to the lower drum surface. ing.

Further, the side wall 190 of the tip portion of the ridge that forms the slag liquid reservoir A has a predetermined height in order to hold the molten slag S.
The cooling drum 10 is rotationally driven by a driving device (not shown) so that the upper drum surface rotates in a rubbing direction. The cooling drum 10 is provided with an internal cooling mechanism (not shown) having a flow path for passing the refrigerant, and a refrigerant supply unit and a refrigerant discharge unit for the internal cooling mechanism are provided at each end of the drum shaft. Is provided. Note that water (cooling water) is generally used as the refrigerant, but other fluids (liquid or gas) may be used.
The tip of the flange 19 may be in contact with the drum surface 100 or may be close to the drum surface 100 by forming a small gap. In the latter case, considering the thermal expansion, it is preferable that the molten slag S be close to the gap so that the molten slag S does not leak. However, in order to reliably prevent the molten slag S from leaking, It is preferable to inject purge gas from the gas injection means 30 provided below.

  In the cooling treatment of the molten slag using the cooling treatment apparatus as described above, the molten slag S supplied to the trough 19 flows into the slag liquid reservoir portion G, where it is cooled by staying for an appropriate time, After being attached to the drum surface 100 of the cooling drum 10 and being taken out and cooled to an appropriate solidified state (for example, a semi-solid state or a state where only one or both surface layers are solidified) At a predetermined drum rotation position, it naturally peels from the surface of the cooling drum due to its own weight, and is discharged to the other side in the radial direction of the cooling drum.

In the cooling processing apparatus having the single cooling drum 10 as described above, since the cooling drum 10 is not subjected to a large drop load due to the molten slag S, the molten slag S can be processed in a large amount without damaging the cooling drum 10. . In addition, since the cooled slag Sx peeled from the drum surface 100 of the single cooling drum 10 is discharged in one direction, it is easy to handle and post-process the cooled slag.
In addition, the cooling processing apparatus having the single cooling drum 10 is a method of supplying the molten slag S to the upper drum surface of the cooling drum 1 from the bowl 19 having an appropriate height, without forming the slag liquid reservoir G, For example, a method in which the molten slag S is directly supplied to the drum surface 100 from the tip of the ridge 19 may be applied.

  Next, the slag cooling method (ii) will be described. In this cooling method, for example, as shown in FIG. 11 (a front view schematically showing the apparatus), a gap 68 is provided in the horizontal direction. The cooling slag is provided between a pair of cooling drums 60a and 60b using a cooling processing apparatus having a pair of cooling drums 60a and 60b having a rotation direction in which the opposing outer peripheral portions rotate downward. Is supplied to form the slag liquid reservoir g, and the molten slag in the slag liquid reservoir g and / or molten slag flowing into the slag liquid reservoir g is cooled by the cooling means 61 and the gap 68 is removed from the slag liquid reservoir g. The molten slag flowing in is rolled while being cooled by a pair of cooling drums 60 a and 60 b, and at least the slag whose surface layer is solidified is extracted downward from the gap 68. In this type of cooling processing method, rolling slag with a pair of cooling drums 60a and 60b refers to extracting the slag downward from the gap 68 between the cooling drums 60a and 60b with at least the surface solidified.

  The cooling drums 60a and 60b are rotationally driven in the rotational direction by a driving device (not shown). Inside the cooling drums 60a and 60b, an internal cooling mechanism (not shown) having a flow path for passing a refrigerant is provided, and a refrigerant supply portion and a refrigerant discharge portion for the internal cooling mechanism are provided at each end of the drum shaft. Each is provided in the section. Note that water (cooling water) is generally used as the refrigerant, but other fluids (liquid or gas) may be used.

At both ends in the cooling drum width direction, weir plates 67 for closing both ends of a recess having a V-shaped cross section (a recess in which the slag liquid reservoir G is formed) formed between the upper outer peripheral surfaces of the cooling drums 60a and 60b. Is provided in contact with the end faces of the cooling drums 60a, 60b. The dam plate 67 is supported by the apparatus main body (base) via an appropriate support member.
Below the pair of cooling drums 60a and 60b, a conveyor 64 is provided for receiving and transporting the slag Sx that is rolled while being cooled by the cooling drums 60a and 60b and extracted from the gap 68.

Cooling means 61 for cooling the molten slag S in the slag liquid reservoir A and / or the molten slag S in the middle of the slag liquid reservoir A is provided above the cooling drums 60a and 60b. The cooling means 61 can be constituted by means for supplying fluid or / and powder to the molten slag S, for example.
If necessary, a cooling device 65 for cooling the slag Sx extracted from the gap 68 between the cooling drums 60a and 60b can be provided between the cooling drums 60a and 60b and the conveyor 64. The cooling device 65 can be configured by, for example, a nozzle that sprays a cooling fluid such as water or air onto the slag Sx.

In the molten slag cooling process using the cooling processing apparatus as described above, the molten slag S is supplied between the upper outer peripheral surfaces (recesses having a V-shaped cross section) of the cooling drums 60a and 60b whose opposing outer peripheral portions rotate downward. As a result, a slag liquid reservoir g is formed. The molten slag S in the slag liquid reservoir g and / or the molten slag S in the middle of flowing into the slag liquid reservoir g are cooled by the cooling means 61 and the molten slag S flowing into the gap g from the slag liquid reservoir A is 1 It is rolled while being cooled by the pair of cooling drums 60a and 60b. By this rolling, the viscous molten slag S is expanded in the cooling drum width direction, and efficient cooling can be performed.
The molten slag S cooled by the cooling means 61 as described above and further cooled by the cooling drums 60a and 60b is extracted downward from the gap 68 as a plate-like slag Sx whose surface layer is solidified. The slag Sx is further cooled by the cooling device 65 as necessary.

FIG. 12 shows an embodiment of the present invention using the above cooling processing apparatus provided with a cooling drum, and the cooling processing apparatus provided with a single cooling drum 10 as shown in FIG. 10 is used. Is. This embodiment belongs to the form (a) described above.
The cooling processing apparatus M has a stretching roll 40 for rolling the molten slag S adhering to the drum surface 100 of the cooling drum 10 and extending it in the drum width direction, and cooling the molten slag having a particularly high viscosity. It is suitable for processing. The spreading roll 40 is rotatably supported by a support arm (not shown) such that the outer peripheral surface forms a predetermined interval with the drum surface 100 of the cooling drum 10.

On the slag discharge side of the cooling drum 10, water mist m is jetted onto the slag Sa that is peeled off from the cooling drum 10 and is being conveyed by the conveyor 13, and further to the slag adhered to the cooling drum 10 and the roll surface of the spreading roll 40. Then, a mist supply means 41 for cooling is provided, and here water spray cooling (step A) is performed.
A filling tank 42 is provided for filling the water-cooled slag and performing an aging process (process B), and a bucket for conveying and charging the slag Sa discharged from the conveyor 13 into the filling tank 42. A conveyor 43 of the type is provided. The filling tank 42 is charged with slag and steam from the top side, and slag / steam is taken out from the bottom side.
The cooling processing apparatus M to the filling tank 42 are covered with a shielding body 44, and the entire shielding body 44 and the filling tank 42 constitute a substantial processing container.

In the present embodiment, the molten slag S is cooled by the cooling processing apparatus M as described in FIG. 10, and the slag Sa discharged from the cooling processing apparatus M is sprinkled with water (injection of water mist). And step A is performed. The slag Sa thus sprayed and cooled is charged into the filling tank 42 from the top by the conveyor 43, and the steam generated in the step A also flows into the filling tank 42 from the top. In the filling tank 42, an aging process is performed in a process in which steam passes through the slag, and the process B is performed.

In carrying out the method of the present invention, it is particularly preferable to efficiently recover the sensible heat of the molten slag from the viewpoints of energy saving and reduction of exhausted CO ₂ .
When cooling slag with a cooling drum as shown in FIGS. 6 to 11, it is preferable to use a refrigerant in the cooling drum from the viewpoint of durability of the cooling drum, and water is generally used as the refrigerant. Although this water is circulated and used, the water temperature rises due to heat removal from the slag in the cooling drum. Therefore, if a part of the cooling water (hot water) that has passed through the water-cooling type cooling drum is used for watering in step A performed in the method of the present invention, it is advantageous in recovering slag sensible heat.

FIG. 13 shows an embodiment thereof. Reference numeral 45 denotes a circulation pipe for circulating cooling water through the cooling drums 10a and 10b. A watering pipe 500 is connected to the circulation pipe 45, and the cooling drum 10a. , 10b, a part of the cooling water is led to the processing vessel D for carrying out the method of the present invention through the sprinkling pipe 500 and sprinkled from the sprinkling mechanism 5 to the slag (step A of the present invention).
In this way, a part of the cooling water of the cooling drums 10a and 10b is taken out and used for watering in the step A of the present invention, so that replenishing water always enters the cooling water of the circulation pipe 45 (in the figure, 46 Is a replenishment tank for cooling water, and 47 is a cooling tower for cooling water.) Since the water temperature is lowered, the cooling facility capacity can be reduced.

The slag to which the method of the present invention is applied may be a slag composition as it is generated, or may be a slag composition adjusted by modification.
As for the method of reforming slag in the melting stage, for example, when the purpose is to reduce the amount of f-CaO in the slag, use oxygen or oxygen-containing gas such as air, oxygen-enriched air, oxygen gas, etc. Can do. When such a gas is supplied to the molten slag, FeO in the slag is oxidized and combined with f-CaO to form 2CaO · Fe ₂ O ₃ , so that the amount of f-CaO in the slag decreases.
Further, for example, by adding an SiO ₂ source such as silica sand and fly ash, an Al ₂ O ₃ source such as alumina brick waste, and an iron oxide source such as iron oxide powder and iron ore powder to the molten slag, f − CaO amount decreases.

○ Example 1
[Example of the present invention]
(I) Cooling process (a) Invention Example 1
Converter decarburization refining (BOF tapping temperature: 1640-1,660 ° C.) occurred in the basicity [mass ratio:% CaO /% SiO _2] slag processing yard 3.8 molten slag of (15 t) in the slag pot And discharged into this yard. Several hours later, the entire amount of the slag whose surface was solidified by being allowed to cool was conveyed by an excavator and charged into a cylindrical processing container D as shown in FIG. The slag surface temperature at this time was 1000-700 degreeC.

(B) Invention Example 2
Using a cooling processing apparatus M provided with a spreading roll 40 as shown in FIG. 12 with respect to the cooling processing apparatus as shown in FIG. 6, by converter decarburization refining (converter steel temperature: 1640 to 1660 ° C.). Molten slag (15 t) having a generated basicity [mass ratio:% CaO /% SiO ₂ ] of 3.8 was transported to the cooling treatment apparatus M with a slag pan, and cooled with this apparatus. The specifications and operating conditions of the cooling processing apparatus M are as follows.
Cooling drums 10a and 10b: 1.6 m outer diameter × length (length in the drum width direction) 3 m, water-cooled stretch roll 40: outer diameter 0.3 m
Gap between the cooling drums 10a and 10b and the extending roll 40: 5 mm
Rotational speed of cooling drums 10a and 10b: 3rpm

In this cooling process, the molten slag in the slag pan 11 is supplied through the slag bar 12 at a supply rate of about 1 t / min for about 12 minutes near the center in the width direction between the upper outer peripheral surfaces of the cooling drums 10a and 10b. did. In order to prevent the molten iron mixed in the slag pan 11 from being supplied to the cooling processing apparatus M, supply of the molten slag S to the cooling processing apparatus M at a stage where about 1/5 of the molten slag S remains in the slag pot 11. Stopped.
The molten slag S supplied to the cooling drum surface is poor in fluidity due to its high viscosity, and is rapidly cooled by contact with the cooling drums 10a and 10b. Therefore, at the supply position, the molten slag S is only about 1 to 2 m in the drum width direction. Although it does not spread, as a result of being rolled from about 10 mm to 5 mm by the extension roll 40, it was extended over almost the entire length in the width direction of the cooling drum, and the molten slag S could be cooled with high cooling efficiency. .
When the surface temperature of the slag Sx was peeled off from the cooling drums 10a and 10b and moved onto the conveyor 13, the surface temperature of the slag S was 700 to 900 ° C. The slag Sx was transported and charged into the cylindrical processing container D as shown in FIG. 3 by the transport conveyor 13 and other transport means.

(Ii) Processing step according to the method of the present invention In the first and second examples of the present invention, the slag is inserted into the cylindrical processing container D shown in FIG. 3 at predetermined time intervals and stays in the processing container. The total amount of was about 24 to 30 tons for two batches, and was continuously processed while maintaining this residence amount.
In the cylindrical processing container D, as described above with reference to FIGS. 2 and 3, watering (step A) with respect to the high-temperature slag and an aging process (process B) with generated superheated steam were performed. The specifications and processing conditions of the cylindrical processing container D are as follows.
-Size of cylindrical processing container: inner diameter 3m x length 10m
・ Processing vessel rotation speed: 1 rpm
・ Watering amount: 0.2 m ³ / t
The slag that had been fined after the treatment was extracted from the slag extraction unit 3, and superheated steam was extracted from the vapor extraction unit 4 and recovered as a heat source fluid. The temperature of the superheated steam at this time was 200-280 degreeC.
Invention Examples 1 and 2 were carried out by changing the slag treatment time (slag residence time in the treatment container), and investigated the influence of the treatment time.

(Iii) Characteristics of treated slag The treated slag taken out was subjected to a water immersion expansion test of JIS method to evaluate the expansion characteristics. FIG. 14 shows the relationship between the slag processing time (slag residence time in the processing container) and the slag expansion coefficient in Examples 1 and 2 of the present invention. Although the expansion rate of unaged converter decarburization refining slag was 5 to 7%, it can be seen that the slag expansion rate was effectively reduced by applying the method of the present invention. The longer the slag treatment time, the lower the slag expansion rate. The slag treatment time is 0.5% or less in 30 minutes, and it is reduced to 0.1% or less in 50 minutes.

[Comparative example]
Converter decarburization refining (BOF tapping temperature: 1640-1,660 ° C.) occurred in the basicity [mass ratio:% CaO /% SiO _2] slag processing yard 3.8 molten slag of (15 t) in the slag pot And discharged into this yard. Then, after watering and cooling, it was crushed to a particle size of 40 mm or less with a jaw crusher.
A steam aging treatment that is generally performed at present was performed on the slag after cooling and crushing. The slag after crushing was stacked in a steam aging apparatus as shown in FIG. 15 for about 1000 t, and steam was flowed from a pipe embedded in the bottom to perform steam aging. In this steam aging, it took 6 to 10 hours to raise the temperature of the slag to 100 ° C. After the slag temperature reached 100 ° C, steam was allowed to flow for 24 to 96 hours to maintain the slag temperature of 100 ° C. As the steam necessary for the steam aging treatment, steam produced by equipment (such as CDQ) in the steel works was used.
In this comparative example, the aging treatment time was changed, and the influence of the treatment time was also investigated. The slag after steam aging was subjected to a water immersion expansion test of JIS method to evaluate the expansion characteristics. FIG. 16 shows the relationship between the steam aging days after the slag temperature reaches 100 ° C. and the slag expansion rate. According to this, the longer the steam aging days, the lower the slag expansion rate, but the slag expansion rate finally becomes 0.5% or less at the steam aging days: 3 days, and it can be seen that aging takes a long time.

Example 2 (Invention Example 3)
The same molten slag as processed in Example 2 of the present invention was processed with equipment as shown in FIG. The molten slag is first cooled by a cooling processing apparatus M having cooling drums 10a and 10b, solidified into a plate having a thickness of about 5 mm, and then charged into a cylindrical cylindrical container D. Steps A and B) were carried out. At that time, a part of the cooling water that passed through the cooling drums 10 a and 10 b was used for watering in the cylindrical cylindrical container D.
In order to generate steam, the amount of water sprayed on the slag in the cylindrical processing vessel D is about 200 kg / t-slag (= steam generation amount) with water of about 30 ° C. In this embodiment, the cooling processing apparatus Since the 70 ° C. cooling water that passed through the M cooling drums 10a and 10b was used for sprinkling, the amount of steam generated increased by 210% / t-slag to 5%.
On the other hand, since a part of the cooling water of the cooling drums 10a and 10b is used for watering, the decreasing amount of water is replenished with room temperature water, but the water temperature is lowered by the amount of the replenishing water. There was a margin, and the amount of cooling water could be reduced from 150 t / H to 130 t / H.

Example 3 (Invention Example 4)
The method of the present invention was carried out using a processing facility provided with two processing containers Xa and Xb (volume: 15 m ³ ) as shown in FIG. Each processing container Xa, Xb is composed of a tiltable container body and a lid.
The slag (15 t) having a slag surface temperature of about 1000 ° C. generated in the cooling treatment process of Example 1 of the present invention was charged into the processing containers Xa and Xb, and the present invention was carried out according to the procedure described with reference to FIG. The amount of water sprayed in the process A performed in each processing container Xa, Xb was 0.2 m ³ per 1 slag of slag, and the water spraying was stopped when the slag surface temperature reached about 500 ° C. Moreover, the recovery steam temperature in the process B performed in each processing container Xa, Xb was 280-180 degreeC.

Graph showing the relationship between the surface temperature of slag subjected to steam aging and the effect of expansion suppression by steam aging Explanatory drawing which shows typically one Embodiment of the method of this invention using a cylindrical processing container Explanatory drawing which shows more concrete embodiment of the method of this invention using a cylindrical processing container Explanatory drawing which shows one Embodiment of the method of this invention using processing container X1, X2 Explanatory drawing which shows one Embodiment of the method of this invention using processing container Xa, Xb The front view which shows typically one Embodiment of the cooling processing apparatus of the molten slag suitable for obtaining the high-temperature slag of the non-molten state to which this invention method is applied, and the cooling processing method The front view which shows typically other embodiment of the cooling processing apparatus of the molten slag suitable for obtaining the high temperature slag of the non-molten state to which this invention method is applied, and the cooling processing method The front view which shows typically a part of other embodiment of the cooling processing apparatus of the molten slag suitable in order to obtain the high temperature slag of the non-molten state to which this invention method is applied Side view schematically showing a part of the embodiment shown in FIG. The front view which shows typically other embodiment of the cooling processing apparatus of the molten slag suitable for obtaining the high temperature slag of the non-molten state to which this invention method is applied, and the cooling processing method The front view which shows typically other embodiment of the cooling processing apparatus of the molten slag suitable for obtaining the high temperature slag of the non-molten state to which this invention method is applied, and the cooling processing method Explanatory drawing which shows other embodiment of this invention incorporating the cooling process of the slag by a cooling drum. Explanatory drawing which shows other embodiment of this invention incorporating the cooling process of the slag by a cooling drum. In an Example, the graph which shows the relationship between the slag processing time (slag residence time in a processing container) in this invention example 1 and 2, and the slag expansion coefficient by the water immersion expansion test of JIS method In an Example, explanatory drawing which shows the steam aging processing method of a comparative example In an Example, the graph which shows the relationship between the steam aging days in a comparative example, and the slag expansion coefficient by the water immersion expansion test of JIS method

Explanation of symbols

X1, X2, Xa, Xb Processing container 1 Cylindrical processing container 2, 2f Slag charging part 3, 3f Slag extracting part 4, 4f Steam extracting part 5, 5f Sprinkling mechanism 6 Hopper part 7 Steam piping 8 Steam introducing part 9 Steam Extraction part 10, 10a, 10b Cooling drum 11 Slag pan 12 Slag bowl 13 Conveyor 14 Slag bucket 15a, 15b Cooling drum 16 Weir 17 Dam plate 18 Opening 19 19 20 Upper lid 20a, 20b Upper lid 21a, 21b Watering nozzle 22a, 22b Steam Introduction part 23a, 23b Steam extraction part 24 Steam pipe 25 Steam pipe 26 Steam pipe 27a, 27b Steam pipe 30 Gas injection means 40 Stretch roll 41 Mist supply means 42 Filling tank 43 Conveyor 44 Shielding body 45 Circulation line 46 Supply tank 47 Cooling tower 60a, 60b Cooling drum 61 Cooling means 64 Conveyor 65 Cooling device 66 Slurry Bucket 67 Dam plate 68 Clearance 90 Steam pipe 100 Drum surface 150 Annular groove 190 Side wall 300, 300f Open / close gate 400 Steam pipe 401 Exhaust port 500, 500f Sprinkling pipe 600 Lid 610, 610f Open / close gate V1, V2, V3, V4, V5 , V6 On-off valve S Molten slag Sa, Sb, Sx Slag g Slag liquid reservoir G Slag liquid reservoir

Claims (11)

A method of cooling and aging one or more slags selected from steelmaking slag and ore smelting reduction slag,
A step (A) for sprinkling the hot slag, and a step (B) for aging the slag by bringing the steam generated by the sprinkling in the step (A) into contact with the slag cooled by the sprinkling. A method for treating slag, wherein the step (A) and the step (B) using the steam generated in this step are performed at different locations.   In step (A), water is sprayed on slag having a surface temperature of 700 ° C. or higher to generate steam having a temperature of 100 ° C. or higher. In step (B), the steam is brought into contact with slag having a surface temperature of 200 to 500 ° C. The slag processing method according to claim 1, wherein an aging process is performed.   The slag processing method according to claim 1 or 2, wherein the slag is granulated by the aging treatment in the step (B) to form a granular slag. Using the processing containers (X1) and (X2), move the slag in the order of the processing container (X1) and the processing container (X2), and then process (A) in the processing container (X1) and process in the processing container (X2). A processing method for sequentially performing (B),
Step (B) for introducing the steam generated in step (A) for the slag of the subsequent charge in the processing vessel (X1) into the processing vessel (X2) and for the slag of the preceding charge in the processing vessel (X2) The slag treatment method according to claim 1, wherein the slag treatment method is used for a slag. Using the processing containers (Xa) and (Xb), the process (A) and the process (B) are sequentially performed in each processing container (Xa) and (Xb), and one processing container (Xa) or In (Xb), the step (A) is performed in the other processing vessel (Xb) or (Xa), and the step (B) is performed.
The steam generated in the step (A) in one processing container (Xa) or (Xb) is introduced into the other processing container (Xb) or (Xa). The method for processing slag according to crab.   The process (A) and the process (B) are sequentially performed on the slag being transferred in the processing container, and the steam generated in the process (A) is further downstream in the slag transfer direction than the sprinkling position in the process (A). The method for treating slag according to any one of claims 1 to 3, wherein the step (B) is performed by contacting the slag.   A cylindrical processing container that includes a slag loading part on one end side and a slag discharge part on the other end side, is inclined downward from one end side toward the other end side, and rotates around a cylindrical axis, The method for processing slag according to claim 6, wherein the step (A) and the step (B) are sequentially performed while transferring the slag in the longitudinal direction in the processing container.   The slag treatment method according to any one of claims 1 to 7, wherein the steam used in the step (B) is recovered as a heat source fluid.   The molten slag is cooled by bringing it into contact with a rotating cooling drum and discharged as high-temperature slag in the form of a plate, column, or strip. The molten slag is cooled, and the high-temperature slag after the cooling is processed. On the other hand, the processing method in any one of Claims 1-8 is performed, The processing method of the slag characterized by the above-mentioned.   The molten slag is cooled while being rolled with a pair of rotating cooling drums and discharged as high-temperature slag in the form of a plate, column, or strip, and the molten slag is cooled, and after the cooling treatment The processing method of any one of Claims 1-8 is performed with respect to high temperature slag, The processing method of the slag characterized by the above-mentioned.   The slag treatment method according to claim 9 or 10, wherein the cooling drum is a water-cooling type, and a part of the cooling water that has passed through the cooling drum is used for watering in the step (A).

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