JP2000144268A - Method for operating exhaust gas desulfurizing apparatus in production of sintered ore in high blending ratio of high crystal water-containing ore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain the water balance in a desulfurizing apparatus for exhaust gas from a sintering machine generated with addition of crystal water content accompanied with the rising of blending ratio of high crystal water-containing ore and to secure the stable operation. SOLUTION: The apparatus provided with a cooling liquid circulating mechanism 5 as an SOx absorbing device 2, an ammonium sulfite absorbing liquid circulating mechanism 6 returning back the ammonium sulfite absorbing liquid in the circulating system of the SOx absorbing device and of an ammonium absorbing device 3 and a dilute SOx liquid circulating mechanism 7 washing the exhaust gas with water before introducing the exhaust gas from the sintering machine into a wet type EP 21, is used. Then, the added crystal water is recovered from the excess water cleaned with the wet type EP as the supplying water source into the dilute SOx liquid circulating course, and from the liquid dividedly discharged on the way of the ammonium sulfite absorbing liquid circulating route and on the way of the cooling liquid circulating route, and a part thereof is extracted and injected from a blast furnace tuyere 9 as the water for adjusting the moisture into a blast furnace. Even in the case of being of the high blending ratio of the high crystal water-containing ore, lime or industrial water in the sintering raw material and the industrial water for adjusting the moisture in the blast furnace are saved without reinforcing the desulfurizing apparatus, and the producing operation of the sintered ore is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the production of sintered ore, which is a main raw material for producing pig iron, in which the ore having a high water content of crystallization, for example, an ore having a high water content of crystallization such as pisolite ore is used as a raw material. The present invention relates to a method for operating a desulfurization facility for exhaust gas generated from a sintering machine when operating at a high temperature.

[0002]

2. Description of the Related Art Conventionally, high-quality ores such as hematite and magnetite have been mainly used as raw materials for sinter. However, in recent years, as the output of these high-quality iron ores has decreased, the usage of pisolite ores containing a large amount of goethite (goethite: Fe ₂ O ₃ .nH ₂ O) has tended to increase. The water content of iron ore conventionally used is about 3 wt.% Or less, but the water content of this pisolite ore is 4 wt.% Or more, and that of high moisture content reaches about 9 wt.%.

When the ore containing high crystal water is used for producing a sintered ore, the water of crystallization is dissociated at about 300 ° C. and becomes porous. Reacts easily with application flux, producing excess melt. Therefore, the air permeability during the sintering process is deteriorated, and the productivity is reduced.

However, it is important to solve the above problems in order to respond to the supply trend of iron ore resources.
Recently, several proposals have been made. All of them correspond to a change in the sintering action in the sintering process due to an increase in the amount of water of crystallization when the mixing ratio of the ore having high crystallization water is increased in the production of sinter. Their purpose is to ensure the quality of sinter and the productivity.

[0005] A common problem in the invention having such a purpose is to find a technical solution to the fact that the ore having a high crystal water content is easily meltable in the sintering process.
For example, Japanese Patent Application Laid-Open No. 6-271951 discloses a method of controlling the amount of heat input during operation of a sintering machine to prevent a decrease in air permeability during sintering (hereinafter referred to as Prior Art 1). Japanese Patent No. 95742 discloses a method of producing a high-yield, high-strength sintered ore by previously granulating a high-crystal water-containing ore together with a return ore (hereinafter referred to as prior art 2). Japanese Unexamined Patent Publication No. Hei 8-269584 discloses a method for maintaining high productivity by coating hardly meltable ore around ore particles having high crystal water content (hereinafter referred to as prior art 3). No.-81717, by equalizing the concentration of crystallization water in the vertical direction in a raw material packed bed on a sintering machine,
A method for producing a sintered ore that ensures high productivity is disclosed (hereinafter referred to as Prior Art 4).

[0006]

SUMMARY OF THE INVENTION
No. 4 shows the case where the proportion of the high crystal water content ore in the sintering raw material was increased in response to the increase in the supply of high crystal water content ore among the iron ores which are the main raw materials of sinter ore. However, it is useful in terms of securing high yield, high quality and productivity of the sinter. However, the operation in which the mixing ratio of the ore containing high crystal water is increased has the following problems in addition to the above problems.
That is, the water content of the exhaust gas generated in the sintering process is increased due to the dehydration of the water of crystallization in the ore containing high crystallization water in the sintering process as compared with the normal operating condition. This increase in water greatly affects the operation of the sintering machine in the operation of the sintering machine and the change in the factor of water balance in the operation system of the exhaust gas desulfurization equipment for the sintering machine.

FIG. 2 shows an example of a schematic flow of the exhaust gas desulfurization equipment for a sintering machine. In the figure, 51 is a sintering machine, 52 is S
O _X absorber, 53 is an ammonia absorber. The desulfurization equipment includes a sintering machine exhaust gas 54 generated from the sintering machine 51.
Is led to the SO _X absorption device 52 where it is desulfurized. SO _X
The absorption device 52 is provided with a cooling liquid circulation mechanism 55, an ammonium sulfite absorption liquid circulation mechanism 57, and a SO _X dilute liquid circulation mechanism 59. In the desulfurization method, first, the exhaust gas 54 of the sintering machine is mainly cooled by the coolant in the coolant circulation mechanism 55. On the other hand, it circulates between the ammonia absorber 53 and the SO _X absorber 52 for recovering the ammonia content in the coke oven gas 56 generated from the coke manufacturing equipment (not shown), and the aqueous solution containing ammonium sulfite circulates. Ammonium sulfite absorption liquid circulation mechanism 5
7 is provided, and the SO _X absorption device 5 in the middle of the route is provided.
2 in the exhaust gas 54 of the sintering machine
Absorbs _OX components. Further, the SO _X dilute liquid circulation mechanism 59
Then, the sintering machine exhaust gas 54 is washed with a water spray 60 to complete the desulfurization. The exhaust gas 54 'after the completion of the desulfurization is then radiated from the chimney 63 via the wet electric dust collector 61 and the denitration device 62.

[0008] As described above, the sintering machine exhaust gas is usually treated in a wet exhaust gas desulfurization facility. Therefore, the increase in the crystal water content is added to the circulating fluid in each circulation mechanism system with the increase in the mixing ratio of the high crystal water content ore. For this reason, the amount of each circulating liquid increases, and the liquid to be treated overflows if left as it is. The following water balance actions are taken in order to stay within the processing capacity of each circulation mechanism and other desulfurization equipment: Sintering machine exhaust gas 5 discharged from the SO _X absorber 52
Increase the moisture content in 4 '. To this end, the discharge temperature of the exhaust gas 54 'of the sintering machine is raised to increase the water vapor pressure in the exhaust gas, thereby increasing the amount of water taken out. For this purpose, an action is taken to increase the proportion of quick lime in the sintering process by a predetermined amount in the sintering process, or the waste liquid is discharged out of the waste liquid treatment devices 64-66 in each circulation mechanism system. Either the action of increasing the water treatment capacity of the waste liquid treatment device 66 to increase the amount of waste water or the like must be taken. The above actions include:
There are problems such as changes in the operating conditions of the sintering machine, the effect on the quality of the sinter ore, and the increase in the basic unit of quicklime. On the other hand, the action (1) requires a large cost such as a facility capacity building construction.

In view of the above, the present invention solves the above-mentioned problem caused by the addition of the crystal water accompanying the increase in the mixing ratio of the ore having a high crystallization water content. It is an object of the present invention to develop a stable operation method of a flue gas desulfurization equipment.

[0010]

SUMMARY OF THE INVENTION From the above-mentioned viewpoints, the present inventors diligently develop a method of operating an exhaust gas desulfurization facility in the case of producing a sintered ore by mixing a large amount of ore containing high crystallization water. Repeated research. As a result, the following findings were obtained. That is,
From the appropriate intermediate position for a predetermined circulation mechanistic pathways provided involved in SO _X absorbing device of the sintering machine exhaust, to find a method for the circulating liquid extracting a part of, and take advantage of this as an alternative to industrial water And And it was found that this industrial water application can be used for adjusting the humidification of air blown to a blast furnace.

The present invention has been made based on the above findings.
The configuration is as follows. Claim 1
The operation method of the exhaust gas desulfurization equipment of
Sintering machine generated from sintering machine in the process of producing sinter
In treating the exhaust gas, SO in the exhaust gas of the sintering machine
_XSO for absorbing components_XThe following equipment is used as an absorber.
Use the device. That is, the main purpose is to cool the exhaust gas of the sintering machine.
Coolant circulation mechanism and the SO_XAbsorber and coke made
Contained in the coke oven gas generated from the
In a circulation system with an ammonia absorption device for collecting
The SO _XThe ammonium sulfite absorption liquid returns to the absorption device
An ammonium sulfate absorption liquid circulation mechanism and its exhaust gas from the sintering machine
Wash the exhaust gas of the sintering machine with water before introducing it to the dust machine
SO intended for processing_XEquipped with a dilute liquid circulation mechanism
Use the one you obtained. And in the production process of this sintered ore
The water separated from the water of crystallization in the ore containing high crystallization water
From the sintering machine exhaust gas containing
In the above step (a), collect
Used to clean the electrodes of the wet type electrostatic precipitator, which is a makeup water source
Of the surplus replenishment water from the blast furnace tuyere to the blast furnace
High crystal, characterized by blowing as minute adjustment steam
High mixing ratio of water-containing ore Exhaust gas desulfurization equipment for sinter production
It is a driving method. Here, the step (a) is defined as SO_Xabsorption
Equipment SO_XSO in waste gas of sintering machine_X
SO with water spray zone to absorb components_XDilute liquid
A circulation path is provided, and the crystallization water is provided in the water spray zone.
Refers to the step of capturing and collecting a part of the minute.

A method for operating an exhaust gas desulfurization facility according to a second aspect of the present invention is the same as the method of the first aspect, except that the following step (b) is further added to the above step (a) as a step of recovering the crystal moisture. Is characterized in that it is collected. Here, in the step (b), the aqueous solution containing sulfur and ammonia is circulated between the SO _X absorber and the ammonia absorber to recover the SO _X component and ammonia, and In the downstream process of the ammonia absorption device in Item 1, ammonium sulfate is produced using the ammonium sulfite-containing solution discharged from the ammonia absorption device, and part of the waste liquid in the ammonium sulfate production process or one of the treatment liquid of the waste liquid is produced. Refers to the step of recovering the crystal water by extracting a part.

A method for operating an exhaust gas desulfurization facility according to a third aspect of the present invention is the same as the method of the second aspect of the present invention, further comprising the following steps (a) and (b) as a step of recovering crystal water. An operation method of an exhaust gas desulfurization facility at the time of production of a high-mixture ratio sintered ore with a high content of ore having a high crystal water, characterized by adding (c). Here, the step (c) means that, in order to absorb the SO _X component in the exhaust gas of the sintering machine and to cool the temperature of the exhaust gas of the sintering machine, the acidic acid sulfite is supplied to the cooling liquid circulation mechanism of the SO _X absorbing apparatus. An ammonium acid sulfite solution circulation path including a spray zone of an aqueous solution containing is provided, a part of the acid ammonium sulfite solution is discharged from the middle of the ammonium acid sulfite solution circulation path, and one of the treatment liquids subjected to the predetermined treatment is discharged. Refers to the step of recovering the crystal water by extracting a part.

[0014]

Next, an embodiment of the present invention will be described. FIG. 1 is a schematic explanatory view showing one embodiment of the present invention. In the figure, 1 is a sintering machine, 2 is SO _X
Absorber, 3 is an ammonia absorber, 8 is a blast furnace, and 9 is a blast furnace tuyere. This desulfurization equipment guides the sintering machine exhaust gas 4 generated from the sintering machine 1 to the SO _X absorption device 2 where it is desulfurized. The SO _X absorbing device 2 is provided with a coolant circulating mechanism 5, an ammonium sulfite absorbing solution circulating mechanism 6, and a SO _X dilute liquid circulating mechanism 7 having basically the same functions as those described in FIG. Then, by circulating a part of the processing solution by the SO _X absorption device 2 to the ammonia absorption device 3 for recovering the ammonia contained in the coke oven gas 16, the absorption efficiency in both devices is improved. As well as producing ammonium sulfate as a by-product.

In the following, each of the three circulation mechanisms will be described, and a part of the surplus circulating liquid in the circulation mechanism will be extracted from a predetermined place in the circulation mechanism, A method according to the present invention will be described in which a part of the surplus water that has been used for the purpose of cleaning is extracted and blown into the tuyere of the blast furnace 9.

(1) Coolant circulation mechanism SO_XThe sintering machine exhaust gas 4 is introduced into the absorber 2 from below.
Then, the desulfurized exhaust gas 4 ′ of the sintering machine is discharged from the top.
You. The inside is divided into three zones, and the lower stage mainly
Is cooled by the coolant, and mainly in the middle and upper stages
SO in exhaust gas_XThe components are ammonium sulfite absorption solution and S
O_XAbsorbed and removed by dilute liquid, complete desulfurization from top
The exhaust gas 4 'from the sintering machine is discharged. Coolant circulation mechanism 5
In the lower stage, the predetermined cooling liquid is
After cooling the exhaust gas, it accumulates at the bottom of the device. this
It is pumped up and circulated to the lower part of the device,
repeat. SO generated by using this cycle as a main path
_TwoAs the pH of the absorbing solution continues to fall,
Concentrated water (NH_ThreeWater) (not shown) to set the pH
It is kept at a value (for example, 5.8) or more. Because of this SO_Two
The absorbing liquid becomes an acidic ammonium sulfite absorbing liquid. This acid ammonium sulfite absorption
The water dehydrated by passing the liquid through the thickener 12 circulates the cooling liquid
Returned to mechanism 5. On the other hand, through the thickener 12,
Through the treated water 11 coming out of the filter press 13 after the treatment.
It is usually returned to the thickener 12, but the high crystal water content
At the time of production of the sintered ore, the return piping
A portion 11a of the treated water from the blast furnace 9
Into the blast furnace 8.

(2) Ammonium sulphite absorption liquid circulation mechanism In the middle stage of the SO _X absorption apparatus 2, the ammonium sulphite absorption liquid circulation mechanism 6 is used to shower 14 a predetermined liquid, and absorbs SO _X in the exhaust gas in this process. After gathering in the receiving container, it is introduced into the ammonia absorbing device 3 through a predetermined route. The introduced liquid is showered 15 in the ammonia absorbing device 3.
Then, during the opposition to the coke oven gas introduced from the lower part of the apparatus, the ammonia contained in the coke oven gas 16 is absorbed and accumulated at the bottom of the apparatus. This is pumped up and circulated in the middle stage of the SO _X absorber 2, and the showering 14 is repeated. Then, at the time of sinter production at a high blending ratio of the ore containing high crystal water, the ore is branched from the ammonium sulfite absorption liquid circulation mechanism 6 at a predetermined time, enters the ammonium sulfite absorption liquid treatment system, and is located in the middle of the system: From point Q, the treated solution 17 of the ammonium sulfite absorption solution
Part 17a of the extracted solution 1
7 a is blown into the blast furnace 8 from the blast furnace tuyere 9. The treated solution 17 is a liquid obtained by treating the ammonium sulfite absorption liquid in the thickener 18 and the waste liquid absorption liquid tank 19.

(3) SO_XDilute liquid circulation mechanism SO_XThe dilute liquid circulation mechanism 7 is_XAbove absorber 2
Then, SO_XThe dilute solution is showered 20 and
SO remaining in the exhaust gas in a short time_XAbsorbs and desulfurizes
Completed and assembled in a receiving container. Then SO_XDilute liquid circulation
SO on the path of mechanism 7_XCirculate to the upper stage of absorber 2
Repeat the power ring 20. SO_XOf the dilute liquid circulation mechanism 7
The circulating fluid contains SO_XIngredients are slightly contained. In addition,
SO_XThe showering 20 in the upper stage of the absorber 2
Sintering machine after desulfurization
The gas 4 ′ is supplied to the wet electric dust collector (wet EP) 21 and the gas
After being treated by the glass-nitting device 22, it is released to the atmosphere from the chimney 23.
You. Here, the dust collecting electrode of the wet type electric dust collecting device 21 is used for industrial purposes.
Rinse intermittently with water 24, and wash washed water 24 'with SO _XRare
It is merged into the system of the thin liquid circulation mechanism 7. And high crystal water
When sinter is produced with a high content of ore, SO_XRare
The amount of circulating liquid in the thin liquid circulation mechanism 7 is usually high for ore containing high crystal water.
Excessive compared to when operating on appropriate standards during compounding
Become. Therefore, the SO_XDilute liquid circulation mechanism
7 to the cleaned water 24 'of the dust collecting electrode which was replenished in a predetermined amount.
Surplus occurs. Therefore, the surplus of the washed water 24 'is removed.
Start out. SO of washed water 24 '_XDilute liquid circulation system 7 series
Of the supply path into the inside: surplus of washed water 24 'from point R
24a ', and blow it into the blast furnace 8 from the blast furnace tuyere 9
Put in.

(4) Behavior and recovery of water of crystallization in ore containing high crystallization water When the water of crystallization in ore containing high crystallization water reaches a high temperature of a predetermined value or more in the sintering process, all water of crystallization is separated from the ore. Then, it becomes steam and enters the exhaust gas of the sintering machine. Therefore, as the crystal water content increases and the ore content ratio of the high crystal water content ore increases, the amount of crystal water mixed into the exhaust gas from the sintering machine increases. The crystal moisture in the exhaust gas of the sintering machine is SO 2
_{In the} process of ascending the _X- absorbing device 2, it is captured by the showering 10, 14, and 20 in the three-circulation mechanism system.
Therefore, by extracting and recovering each liquid from the points P, Q, and R in each system, water of crystallization is indirectly recovered. The priority of the extraction position of each liquid is set higher as the S content in the extraction liquid is lower, and the amount of extraction needs to be determined according to the operating conditions of the sintering machine and the capacity of each part of the equipment. .

[0020]

Next, the operation of the desulfurization equipment of the present invention will be described in more detail with reference to examples. Using the equipment of the apparatus flow shown in FIG. 1, each of the above liquids was extracted from points P, Q and R in the same figure and blown from the blast furnace tuyere, which was used as a substitute for industrial water for blast furnace humidification. . Table 1 shows the test operating conditions. The sinter production is 15000 t / day, and the content of water of crystallization in the ore is 3 wt.% Of the conventional ore, and 9 wt.% Of the ore with high crystallization water. And the compounding ratio is
It was 10 wt.% In the comparative test operation, and 40 wt.% In the example test operation. And the amount of ore charged to the sintering machine is 6
11 t / h.

Under the above operating conditions, in the embodiment, the treated solution 11 corresponding to a water content of 11 t / h, which corresponds to an increase in crystal water generated due to an increase in the mixing ratio of the ore having a high crystal water content. , 17 or the cleaning liquid 24 was withdrawn from each position: points P, R and Q of the exhaust gas desulfurization equipment of the sintering machine. Table 2 shows an example of a liquid amount after the treatment and a liquid analysis result extracted from each position.

[0022]

[Table 1]

[0023]

[Table 2]

On the other hand, an increase in the amount of crystallization water of 11 t / h was
_In order to balance water in the exhaust gas desulfurization equipment of the sintering machine due to the increase in the amount of water vapor in the exhaust gas 4 'from the _X- absorber 2, the temperature of the exhaust gas 4' must be adjusted during normal operation (mixing of ore containing high crystal water). When the compounding ratio of the ore containing high crystal water is increased to 40 wt.
It was necessary to increase. In order to raise the temperature of the exhaust gas 4 'by only this (only 3 ° C), the lime content of the sintering raw material was 0.8 wt. Was increased to 40 wt.%, It had to be 1.2 wt.%. Since the recovered water was blown from the tuyere 9 of the blast furnace, the industrial water for adjusting the blast moisture of the blast furnace was reduced by 11 t / h.

[0025]

As described above, according to the present invention,
In long-term or short-term fluctuations in the mixing ratio of high-crystal water-containing ore in sinter production, in order to secure the water balance in the sintering plant exhaust gas desulfurization facility, investment in the enhancement of the desulfurization facility, Without modifying or changing the sinter production conditions
Good measures can be taken and stable operation can be ensured, and industrial water and quick lime can be saved, resulting in industrially useful effects.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of the present invention.

FIG. 2 is an example of a schematic flow chart of a conventional exhaust gas desulfurization equipment for a sintering machine.

[Explanation of symbols]

1 sintering machine 2 SO _X absorbing device 3 ammonia absorber 4 sintering machine flue gas 4 'desulfurization after sintering machine exhaust 5 coolant circulation mechanism 6 nitrous ammonium sulfate absorption liquid circulation mechanism 7 SO _X dilute solution circulating mechanism 8 blast 9 blast feather Mouth 10 Showering 11, 11a Treated water 12 Thickener 13 Filter press 14, 15 Showering 16 Coke oven gas 17, 17a Treated ammonium sulfite absorption liquid 18 Thickener 19 Waste liquid absorption liquid tank 20 Showering 21 Wet electric dust collector 22 Denitration Apparatus 23 Chimney 24 Industrial water 24 ', 24a' Washed water 25 Circulating storage tank 26 Waste liquid treatment device 27 Coke oven 51 Sintering machine 52 SO _X absorption device 53 Ammonia absorption device 54 Sintering machine exhaust gas 54 'Sintering machine after desulfurization Exhaust gas 55 Cooling liquid circulation mechanism 56 Coke oven gas 57 Ammonium sulfite absorption liquid circulation mechanism 58 Spray Liquid 59 SO _X dilute solution circulating mechanism 60 water spray 61 wet electrostatic precipitator 62 denitrator 63 chimney 64 65 66 waste liquid treatment apparatus 67 circulating reservoir 68 Thickener

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Shimogori 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Inventor Hiromi Nakamura 1-1-2, Marunouchi, Chiyoda-ku, Tokyo F-term (reference) in Nippon Kokan Co., Ltd. 4D002 AA02 AC10 BA02 BA13 CA01 CA13 DA05 DA07 DA11 EA02 EA07 FA06 GA02 GA03 GB02 GB03 GB08 GB09 4K001 AA10 BA02 CA40 CA44 GA10 GB09 GB10 4K012 BD05

Claims (3)

[Claims] In treating sintering exhaust gas generated from a sintering machine in the process of producing a sinter using an ore containing high crystal water, SOx which absorbs the SO _X component in the sintering exhaust gas is treated. _{As an X} absorber, a coolant circulation mechanism for absorbing the SO _X component in the exhaust gas of the sintering machine and cooling the exhaust gas of the sintering machine, and a coke oven generated from the SO _X absorbing device and the coke manufacturing equipment An ammonium sulfite absorption liquid circulation mechanism configured by a circulation system with an ammonia absorption device for recovering ammonia contained in the gas, wherein the ammonium sulfite absorption solution returns to the SO _X absorption device;
Prior to introducing the sintering machine flue gas wet electrostatic precipitator, the sintering machine exhaust and a SO _X diluate circulation mechanism for water washing process, using the SO _X absorbing device, the sinter In the production process, a part of the crystal water is recovered from the sinter exhaust gas containing water from which the water of crystallization in the ore containing high crystal water is separated by the following step (a), and the step (a) is performed. A surplus of makeup water used for washing the electrodes of the wet electric dust collector, which is a makeup water source,
A method for operating an exhaust gas desulfurization facility at the time of producing a high content sinter of an ore containing high crystal water, wherein the ore is blown from a tuyere of the blast furnace to the blast furnace as water for adjusting the humidity of the blast. Step (a): The SO _X dilute solution circulation mechanism is provided with an SO _X dilute solution circulation path including a water spray zone for absorbing the SO _X component in the exhaust gas of the sintering machine. Capture and collect some of the water. 2. The ore containing high crystal water according to claim 1, wherein the crystal water is recovered by adding the following step (b) to the step (a) as the crystal water recovery step. Method of operating flue gas desulfurization equipment at the time of production of high mixing ratio sintered ore. Step (b): an aqueous solution containing sulfur and ammonia is circulated between the SO _X absorption device and the ammonia absorption device to collect the SO _X component and the ammonia, and the ammonia absorption device In the downstream step, ammonium sulfate is produced using the ammonium sulfite-containing solution discharged from the ammonia absorption device, and a part of the waste liquid of the ammonium sulfate production step, or a part of the processing liquid of the waste liquid is extracted to extract the part. The crystal water is recovered. 3. The ore containing highly crystalline water according to claim 2, wherein the following step (c) is further added to the steps (a) and (b) as the crystal water recovery step. How to operate the exhaust gas desulfurization equipment when producing high mixing ratio sintered ore. Step (c): The coolant circulating mechanism of the SO _X absorption device contains ammonium acid sulfite to absorb the SO _X component in the exhaust gas of the sintering machine and to cool the temperature of the exhaust gas of the sintering machine. Provide an acidic ammonium sulfite solution circulation route including a spray zone of the aqueous solution, from the middle of the acidic ammonium sulfite solution circulation route,
A part of the acidic ammonium sulfite solution is discharged, and the crystal water is recovered by extracting a part of the treated liquid subjected to a predetermined treatment.