JP6999473B2 - Flash smelting furnace cooling method and flash smelting furnace cooling structure - Google Patents

Description

The present invention relates to a method for cooling a flash smelting furnace and a cooling structure for the flash smelting furnace.

In recent years, copper concentrate, which is the main raw material for copper smelting, has a tendency for the copper grade to decline, while the sulfur grade has tended to rise. Need to increase. In addition, due to the increase in the grade of sulfur, which is the heat generation source, the amount of heat generated in the flash smelting furnace increases, and the heat load fluctuates greatly due to changes in the raw material composition. Strengthening the body cooling mechanism is indispensable. As a cooling mechanism for such a furnace body, a water-cooled jacket that can be mounted on the wall surface of a flash smelting furnace has already been proposed (see Patent Documents 1, 2, etc.).

Japanese Patent No. 5441593 Japanese Patent No. 551601

At present, the heat flux to the wall surface of the flash smelting reactor reaction shaft has increased by about 25% compared to 10 years ago due to the increase in the amount of raw material processed and the quality of sulfur, which is a heat source. Due to this effect, the coating thickness of the surface of the copper water-cooled jacket constituting the reaction shaft furnace wall is reduced, and peeling or falling off occurs during operating fluctuations, and the speed at which the jacket body is melted is accelerating. Further, due to the influence of the reducing component in the recycled raw material whose processing amount has been increasing in recent years, the coating mainly composed of oxides is reduced, and the water-cooled jacket acts in a direction in which it is easily melted. In addition, as the reaction frame becomes larger as the processing amount increases, the reaction frame approaches the shaft furnace wall surface due to the temporary deterioration of the reaction in the furnace, and the heat flux increases rapidly, which promotes melting damage. The phenomenon is also likely to occur.

If the distance between the inner surface of the furnace and the water channel of the water-cooled jacket is reduced in order to enhance the cooling effect of the inner surface of the furnace, the cooling effect will be enhanced. If it is damaged, water leakage from the water-cooled jacket will occur frequently, which will not only reduce production, but also increase the risk of steam explosion due to water leakage into the furnace. For example, as a countermeasure, strengthening the cooling performance of the reaction shaft can be mentioned, but if the structural members constituting the reaction shaft are modified for that purpose, not only a long construction period but also a huge investment is required, and in some cases, the building structure is required. It is not realistic because it is forced to remodel.

Therefore, the present invention has been made in view of the above problems. By using a water-cooled jacket having a high cooling effect and a reduced risk of steam explosion, it is not necessary to renew the structural members constituting the reaction shaft, and the furnace is used. It is an object of the present invention to provide a cooling method for a flash smelting furnace and a cooling structure for the flash smelting furnace, which can surely maintain the health of the body with a small investment amount.

In order to solve the above-mentioned problems, the present invention according to claim 1 has a water-cooled jacket as a side wall of the shaft mounted between the shelf plates, which are fixed structures constituting the shaft of the flash smelting furnace. In the cooling method of the flash smelting furnace that cools the inner surface of the water-cooled jacket located inside the furnace by supplying cooling water to the water channel provided in the water-cooled jacket, the water- cooled jacket located inside the furnace. Cooling of a flash smelting furnace, characterized in that the magnitude of the temperature gradient from the inside of the furnace to the outside of the furnace in the section from the inner surface of the furnace to the water channel closest to the water cooling jacket is within the range of 2 to 7 ° C./mm. Provide a method.

In order to solve the above problems, the present invention according to claim 2 is the cooling method for the flash smelting furnace according to claim 1, wherein the water-cooled jacket is mounted between the shelf plates which are the fixed structures. A plate-shaped first water-cooled jacket and a second water-cooled jacket having a plurality of fins protruding inward of the furnace and mounted so as to be located between the shelf board and the first water-cooled jacket. , The temperature gradient is controlled by arranging a fireproof material between the fins of the second water-cooled jacket.

In order to solve the above problems, the present invention according to claim 3 has a fin length of 100 to 200 mm and a thickness of 50 in the flash smelting furnace cooling method according to claim 2. It is characterized in that the distance between the fins is 50 to 100 mm and the distance between the fins is 50 to 100 mm.

In order to solve the above problems, the present invention according to claim 4 is the cooling method for the flash smelting furnace according to claim 2 or 3, from the inner surface of the furnace located most inside the first water-cooled jacket. The distance of the section to the nearest water channel of the first water-cooled jacket and the distance of the section from the inner surface of the furnace located inside the furnace of the second water-cooled jacket to the nearest water channel of the second water-cooled jacket. Is characterized by having the same distance.

In order to solve the above problems, the present invention according to claim 5 is the method for cooling a flash smelting furnace according to any one of claims 2 to 4, wherein the layout of the fixed structure is not changed. It is characterized in that the temperature gradient is controlled by changing the layout of the water channel of one water-cooled jacket or at least one of the fin sizes of the second water-cooled jacket.

According to the cooling method of the flash smelting furnace and the cooling structure of the flash smelting furnace according to the present invention, the water-cooled jacket is melted by securing a distance between the inner surface of the furnace and the water channel of the water-cooled jacket and making the temperature gradient gentle. Since it was decided to stabilize the coating by arranging refractory materials between the large fins while reducing the risk of steam explosion due to the reaction shaft, it is not necessary to renew the structural members that make up the reaction shaft, and the furnace body It has the effect of ensuring that soundness can be maintained with a small investment amount.

It is a schematic front sectional view of the flash smelting furnace which concerns on one preferable embodiment of this invention. It is explanatory drawing of the structure of the peripheral wall (side wall) of a reaction shaft. (A) is a plan view of the first water-cooled jacket, and (B) is a cross-sectional view thereof. (A) is a rear view of the second water-cooled jacket, and (B) is a sectional view thereof. It is sectional drawing which shows the structure of the peripheral wall (side wall) of a reaction shaft. (A) is a diagram showing the temperature gradient from the inside of the furnace to the outside of the furnace of the first water-cooled jacket, and (B) is a diagram showing the temperature gradient from the inside of the furnace to the outside of the furnace of the second water-cooled jacket. It is sectional drawing which shows the structure of the peripheral wall (side wall) of the conventional reaction shaft which is a comparative example. (A) It is a figure which shows the temperature gradient from the inside of the furnace to the outside of the furnace of the conventional water-cooled jacket arranged at the position corresponding to the 1st water-cooled jacket, and (B) is the position corresponding to the 2nd water-cooled jacket. It is a figure which shows the temperature gradient from the inside of the furnace to the outside of the furnace of the conventional water-cooled jacket which was arranged.

Hereinafter, the cooling method of the flash smelting furnace and the cooling structure thereof according to the present invention will be described in detail based on a preferred embodiment.

[Structure of flash smelting furnace]
First, the configuration of the flash smelting furnace according to the present embodiment will be briefly described. FIG. 1 is a schematic front sectional view of a flash smelting furnace according to a preferred embodiment of the present invention. The illustrated self-melting furnace 1 is roughly described as a reaction shaft 2 provided on one end side, an uptake 4 provided on the other end side, and a setler 3 located between the reaction shaft 2 and the uptake 4. The whole furnace body of the flash smelting furnace 1 is formed of a shell (can body) made of a metal material such as a steel material. The reaction shaft 2 has a substantially cylindrical shape, and a concentrate burner 7 is arranged on the reaction shaft 2. The concentrate burner 7 is provided with an oxygen-enriched air supply unit 8. When the concentrate (smelting raw material) is blown into the reaction shaft 2 from the concentrate burner 7 at the same time as oxygen-enriched air or high-temperature hot air, a chemical reaction occurs instantaneously, and the reacted concentrate (smelting raw material) has a specific density. Due to the difference, the mat (lower layer) and the slag (upper layer) are separated on the lower part 1a of the smelter 3. The mat level of the settler 3 is provided with a mat tap hole (not shown), and the slag level of the settler 3 is provided with a slag tap hole (not shown). The slag tap hole is connected to a slag furnace (not shown), and the copper contained in the slag is recovered as a mat. On the other hand, in the uptake 4, the exhaust gas in the upper layer of the slag is guided to the waste heat boiler to recover the waste heat, and the cooled exhaust gas is sent to the sulfuric acid factory. Here, a plurality of water-cooled jackets 10 are mounted on the peripheral wall (side wall) of the reaction shaft 2. The water-cooled jacket 10 may be attached to the whole or a part of the peripheral wall (side wall) of the reaction shaft 2, but at least the tubular shape directly above the skirt portion 9a located at the lowermost part of the peripheral wall (side wall). It is assumed that the water-cooled jacket 10 is attached to the portion 9b. This is because the heat flux is particularly high because the high-temperature gas generated by the reaction between the concentrate blown from the concentrate burner 7 and the oxygen-enriched air comes into direct contact with the tubular portion 9b.

[Side wall of reaction shaft]
Next, the structure of the peripheral wall (side wall) of the reaction shaft 2 will be described. FIG. 2 is an explanatory diagram of the structure of the peripheral wall (side wall) of the reaction shaft. As shown, a fixed structure 10c, which is a framework of the side wall, is arranged on the peripheral wall (side wall) of the reaction shaft 2. In the fixed structure 10c, a plurality of ring-shaped shelves are repeatedly arranged in the height direction, and these shelves are supported by a plurality of columns (see FIG. 5). In each stage of the fixed structure 10c, a plurality of water-cooled jackets 10 serving as side walls of the reaction shaft 2 are arranged side by side in the circumferential direction of the reaction shaft 2 (hereinafter, simply referred to as “circumferential direction”), and these plurality of water-cooled jackets are arranged side by side. 10 constitutes a tubular peripheral wall (side wall). The individual water-cooled jacket 10 is provided with a plate-shaped first water-cooled jacket 10a mounted between the fixed structures 10c (gap between the shelves) and a plurality of cooling fins 30 protruding inward in a multi-stage manner. There are two types of the second water-cooled jacket 10b, which are mounted so as to be located between the first water-cooled jacket 10a. A cooling water channel (reference numeral 11 in FIGS. 3 and 4 described later) is provided inside the first water-cooled jacket 10a and the second water-cooled jacket 10b, and the cooling water is supplied to the cooling water channel. The first water-cooled jacket 10a and the second water-cooled jacket 10b are cooled on the inner surface 2a (the surface located most inside the furnace) side. In particular, in the present embodiment, by configuring the water-cooled jacket 10 as described later, an appropriate temperature gradient of 2 to 7 ° C./mm from the inner surface 2a of the furnace to the outside of the furnace during the operation of the flash smelting furnace 1 is appropriate. Control within range. The temperature inside the furnace of the reaction shaft 2 during operation is about 1,200 to 1,400 ° C.

[Structure of the first water-cooled jacket]
Next, the structure of the first water-cooled jacket 10a will be described. 3A is a plan view of the first water-cooled jacket, FIG. 3B is a cross-sectional view thereof, and FIG. 5 is a cross-sectional view showing the structure of the peripheral wall (side wall) of the reaction shaft. The illustrated first water-cooled jacket 10a includes a pair of mounting portions 21 arranged on the left and right in order from the outside of the furnace, and a jacket main body 20 in which the cooling water passages 11 are arranged in a meandering manner. The jacket body 20 has a substantially annular shape when viewed from above, and a pair of mounting portions 21 are arranged so as to project to the outside of the furnace at both ends thereof. The pair of mounting portions 21 and the jacket body 20 of the first water-cooled jacket 10a are formed by integrally casting a metal pipe serving as a cooling water channel 11 inside the jacket body 20. Then, as shown in FIG. 5, a plurality of first water-cooled jackets 10a are arranged in the circumferential direction of the reaction shaft 2 so as to be adjacent to a predetermined position of the fixed structure 10c.

[Refractory layer of the first water-cooled jacket]
Next, the refractory layer around the first water-cooled jacket 10a will be described. As shown in FIG. 5, in the gap (space) between the first water-cooled jacket 10a and the cooling fin 30 of the second water-cooled jacket 10b to be described later, there is a refractory material, for example, a standard refractory such as refractory bricks. The object 31A is arranged. The inner surface 2a of the first water-cooled jacket 10a and the inner surface 2a of the standard refractory 31A are covered with an atypical refractory such as an alumina-chromia castable. As a result, the refractory layer 31 is formed on the side of the inner surface 2a of the furnace of the first water-cooled jacket 10a. Then, the pair of mounting portions 21, the jacket body 20, the cooling fins 30, and the cooling water channel 11 of the first water-cooled jacket 10a are formed of a metal having high thermal conductivity, for example, copper, and the cooling water flows in the cooling water channel 11. By doing so, the refractory material layer 31 can be efficiently cooled.

[Cooling channel of the first water-cooled jacket]
Next, the cooling water channel 11 of the first water-cooled jacket 10a will be described. As shown in FIGS. 3A and 3B, a supply port 12 for supplying cooling water to the cooling water channel 11 is arranged on the outside of the furnace of one mounting portion 21 of the first water cooling jacket 10a, and the first is A discharge port 13 for discharging cooling water from the cooling water channel 11 is arranged on the outside of the furnace of the other mounting portion 21 of the water cooling jacket 10a. The cooling water channel 11 extends linearly from the supply port 12 to the side of the jacket body 20 via one mounting portion 21, then meanders inside the jacket body 20, and then connects the other mounting portion 21. It is piped so as to extend linearly toward the discharge port 13 via the pipe. The formation destinations of the supply port 12 and the discharge port 13 may be opposite. The length between the inner surface 2a of the furnace and the cooling water channel 11 located closest to the inner surface 2a of the furnace is substantially the same as the length of the cooling fins 30 of the second water cooling jacket 10b, which will be described later. Further, it is not necessary that all the first water-cooled jackets 10a have the same structure. For example, as shown in FIG. 3A, one of the first water-cooled jackets 10a adjacent to each other in the circumferential direction is a reaction shaft 2. The other may be inverted with respect to a straight line extending in the radial direction (hereinafter, simply referred to as “diameter direction”).

[Structure of the second water-cooled jacket]
Next, the structure of the second water-cooled jacket 10b will be described. FIG. 4A is a rear view of the second water-cooled jacket, and FIG. 4B is a sectional view thereof. As shown in FIG. 4B, the second water-cooled jacket 10b has a pair of mounting portions 21, a jacket main body 20 having a cooling water channel 11, and a plurality of coolings projecting in a multi-stage manner from the outside of the furnace. It is configured to include fins 30 (two cooling fins in this embodiment). The jacket body 20 and the cooling fins 30 of the second water-cooled jacket 10b are integrally cast with a metal pipe serving as a cooling water channel 11 inside the jacket body 20. Then, as shown in FIG. 5, the second water-cooled jacket 10b is located at a predetermined position of the fixed structure 10c and is located between the second water-cooled jacket 10a and the first water-cooled jacket 10a in the circumferential direction of the reaction shaft 2. Multiple places are placed in.

[Refractory layer of the second water-cooled jacket]
Next, the refractory layer around the second water-cooled jacket 10b will be described. As shown in FIG. 5, for example, a standard refractory material 31A such as refractory bricks is arranged in the gap (space) of the multi-stage cooling fins 30 of the second water-cooled jacket 10b, and the furnace inner surface 2a of the multi-stage cooling fins 30 is arranged. The inner surface 2a of the standard refractory 31A is covered with an atypical refractory such as alumina-chromia castable. As a result, the refractory layer 31 is formed on the side of the inner surface 2a of the furnace of the second water-cooled jacket 10a. The refractory layer 31 is integrated with the refractory layer 31 formed on the inner surface 2a of the furnace of the first water-cooled jacket 10a described above. Then, the jacket body 20, the cooling fins 30, and the cooling water channel 11 of the second water-cooled jacket 10b are formed of a metal having high thermal conductivity, for example, copper, and the cooling water is circulated in the cooling water channel 11 to allow the cooling water to flow through the cooling water channel 11. The layer 31 can be cooled efficiently.

[Cooling channel of the second water-cooled jacket]
Next, the cooling water channel 11 of the second water-cooled jacket 10b will be described. As shown in FIGS. 4A and 4B, a supply port 12 for supplying cooling water to the cooling water channel 11 is arranged at the upper right end of the back surface of the second water cooling jacket 10b, and the back surface of the second water cooling jacket 10b. A discharge port 13 for discharging cooling water from the cooling water channel 11 is arranged at the lower right end. The cooling water channel 11 extends linearly from the supply port 12 at the upper right end toward the inside of the furnace, then meanders inside the jacket body 20 in a C shape, and then extends linearly toward the outside of the furnace. , It is piped so as to face the discharge port 13 on the lower right side. The formation destinations of the supply port 12 and the discharge port 13 may be opposite. Further, it is not necessary that all the second water-cooled jackets 10b have the same structure. For example, one of the second water-cooled jackets 10b adjacent in the circumferential direction has a shape in which the other is inverted with respect to a straight line extending in the radial direction. You may be doing it.

[About the size of the water-cooled jacket]
Next, the size of the water-cooled jacket 10 will be described. In the present embodiment, the length of the jacket body 20 of the first water-cooled jacket 10a in the radial direction is 400 to 500 mm, the length from the inner surface 2a of the furnace to the cooling water channel 11 is 150 to 250 mm, the thickness is 50 to 100 mm, and the height is high. The distance between the first water-cooled jackets 10a adjacent to each other in the direction is set to 200 to 400 mm. Further, in the present embodiment, the protruding length of the cooling fin 30 of the second water-cooled jacket 10b is 100 to 200 mm (preferably 160 to 200 mm), the radial length of the jacket body 20 is 200 to 300 mm, and the cooling fin is used. The thickness of 30 is 50 to 100 mm, and the distance between adjacent cooling fins 30 in the height direction is 50 to 100 mm. The number of cooling fins 30 of the second water-cooled jacket 10b is "2". Further, the inner surface 2a of the first water-cooled jacket 10a (the surface located most inside the furnace) and the inner surface 2a of the second water-cooled jacket 10b (the surface located most inside the furnace) are both on substantially the same cylindrical side surface. Is located in.

[About waterway layout]
Next, the water channel layout of the water-cooled jacket 10 will be described. In the present embodiment, as shown in FIG. 5, the distance from the inner surface of the furnace 2a to the nearest cooling water channel 11 of the first water-cooled jacket 10a and the distance from the inner surface 2a of the furnace to the nearest cooling water channel 11 of the second water-cooled jacket 10b. Is almost equidistant.

[Water cooling method]
Next, a water cooling method using the water cooling jacket 10 according to the present embodiment will be described. In the flash smelting furnace 1, the refractory layer 31 is positively cooled by flowing cooling water from the supply port 12 of the cooling water channel 11 at a predetermined flow velocity and discharging it from the discharge port 13 to stabilize the flash smelting furnace 1. You can operate. Further, the strength of cooling can be adjusted by appropriately adjusting the flow rate of the cooling water to the cooling water channel 11. In this case, use the data of constant monitoring by the thermocouple to increase the flow rate of the cooling water when the measured temperature rises, and reduce the flow rate of the cooling water when the temperature stabilizes. You can also do it.

[Comparison example]
Next, as a comparative example, the peripheral wall (side wall) of the conventional reaction shaft 2 will be described. FIG. 7 is a cross-sectional view showing the structure of the peripheral wall (side wall) of the conventional reaction shaft, which is a comparative example. The layout of the fixed structure 10c is common between the comparative example (FIG. 7) and the present embodiment (FIG. 5), and the operating conditions (water cooling conditions, etc.) are also common. However, in the comparative example (FIG. 7), the water-cooled jacket 100b corresponding to the second water-cooled jacket 10b has a different shape, and the size (thickness, spacing) of the unevenness inside the furnace of the cooling fin 300 corresponding to the cooling fin 30 is different. , Length) is also smaller than that of the present embodiment (FIG. 5), and the number is "4", which is larger than that of "2" of the present embodiment (FIG. 5). Further, in the comparative example (FIG. 7), the furnace inner surface 2a of the water-cooled jacket 100b corresponding to the second water-cooled jacket 10b is recessed outside the furnace than the furnace inner surface 2a of the water-cooled jacket 100a corresponding to the first water-cooled jacket 10a. I'm out. Therefore, in the comparative example (FIG. 7), the position of the inner surface 2a of the furnace is uneven. Further, in the comparative example (FIG. 7), the cooling water channel 110 of the water-cooled jacket 100a is arranged near the inner surface 2a of the furnace, and the distance from the inner surface 2a of the furnace to the cooling water channel 110 closest to the water-cooled jacket 100a is water-cooled from the inner surface 2a of the furnace. It is shorter than the distance to the nearest cooling water channel 110 of the jacket 100b. Further, the refractory layer 31 in the comparative example (FIG. 7) does not include the standard refractory 31A and is composed only of the non-standard refractory.

[Comparison of structure with comparative example]
Next, the structure of the present embodiment (FIG. 5) is compared with the structure of the comparative example (FIG. 7). In the present embodiment, the second water-cooled jacket 10b is provided with a large cooling fin 30, which is different in shape from the water-cooled jacket 100b of the comparative example which does not have the large cooling fins. Further, in the present embodiment, the inner surface 2a of the second water-cooled jacket 10b and the inner surface 2a of the first water-cooled jacket 10a are located on substantially the same cylindrical side surface. Therefore, in the present embodiment, the thickness of the cooling fins 30 approaches the thickness of the tip of the first water-cooled jacket 10a, and the distribution of the inner surface 2a of the furnace is also flattened. Further, in the comparative example (FIG. 7), since the cooling water channel 110 of the water cooling jacket 100a is located near the inner surface 2a of the furnace, the cooling effect of this portion is high, and the temperature gradient is steep in this portion. In the water-cooled jacket 100b, the cooling water channel 110 is located outside the furnace with respect to the water-cooled jacket 100a, so that the cooling effect is lower and the temperature gradient is gentle. Therefore, if the coating in the furnace is melted, the cooling water channel 110 of the water cooling jacket 100a is endangered. On the other hand, in the present embodiment, the buried depth distribution of the cooling water channel 11 (the distribution of the distance from the inside of the furnace to the nearest cooling water channel 11) is made uniform, so that the temperature gradient is averaged at any position and the furnace. The cooling water channel 11 is safely protected even if the inner coating is melted.

[Comparison of temperature distribution with comparative example]
Next, the temperature gradient of the present embodiment (FIG. 6) is compared with the temperature gradient of the comparative example (FIG. 8). FIG. 6A is a diagram showing the temperature gradient from the inside of the furnace to the outside of the furnace of the first water-cooled jacket, and FIG. 6B is a diagram showing the temperature gradient from the inside of the furnace to the outside of the furnace of the second water-cooled jacket. be. Further, FIG. 8A is a diagram showing a temperature gradient from the inside of the furnace to the outside of the furnace of the conventional water-cooled jacket arranged at a position corresponding to the first water-cooled jacket, and FIG. 8B is the second figure. It is a figure which shows the temperature gradient from the inside of the furnace to the outside of the furnace of the conventional water-cooled jacket arranged at the position corresponding to the water-cooled jacket. The horizontal axis of the graph indicates the position, and the vertical axis indicates the temperature. In the graph, the reference numeral a indicates the position of the inner surface 2a of the furnace, and the reference numeral d indicates the position of the cooling water channels 11 and 110 closest to the inner surface 2a of the furnace.

First, in the present embodiment, the burial depth of the cooling water channel 11 in the first water-cooled jacket 10a (distance from the inside of the furnace to the nearest cooling water channel 11) and the burial depth of the cooling water channel 11 in the second water-cooled jacket 10b (furnace). Since the distance from the inside to the nearest cooling water channel 11) is approximately the same distance, the temperature gradient (FIG. 6 (A)) between the furnace inner surface 2a and the cooling water channel 11 is averaged and is almost the same at any position for comparison. There is no place showing a steep temperature gradient as in the example (FIG. 8 (A)). In the comparative example (FIG. 8 (A)), the temperature gradient at a steep portion is 10 to 22 ° C./mm, whereas in the present embodiment (FIG. 6 (A)), the temperature gradient is 2 to 7 ° C. at any location. It becomes / mm (2 to 5 ° C./mm depending on the conditions).

Further, in the present embodiment, the second water-cooled jacket 10b is provided with a large cooling fin 30, and the standard fireproof material 31A is arranged in the gap between the cooling fins 30, so that the cooling water channel 11 is provided from the furnace inner surface 2a in the second water-cooled jacket 10b. The temperature gradient (FIG. 6 (B)) up to is gentler than that of the comparative example (FIG. 8 (A)). In the comparative example (FIG. 8 (B)), the temperature gradient is 5 to 10 ° C./mm, whereas in the present embodiment (FIG. 6 (B)), the temperature gradient is 2 to 7 ° C./mm (2 depending on the conditions). ~ 5 ° C / mm).

Further, in the present embodiment, the burial depth of the cooling water channel 11 (distance from the inside of the furnace to the nearest cooling water channel 11) is substantially the same between the first water-cooled jacket 10a and the second water-cooled jacket 10b. The position where the temperature drops to the lowest level can be approximately the same, i.e., averaged between the first water-cooled jacket 10a and the second water-cooled jacket 10b (FIGS. 6A, 6B).

Further, in the present embodiment, the distribution of the inner surface 2a of the furnace is flattened between the first water-cooled jacket 10a and the second water-cooled jacket 10b, and the pitch and thickness of the tip of the first water-cooled jacket 10a and the cooling fins 30 are adjusted. Since it is made uniform, the temperature gradient from the inside of the furnace to the outside of the furnace can be made substantially the same between the first water-cooled jacket 10a and the second water-cooled jacket 10b (FIGS. 6A and 6B). ).

[Comparison of dissolution loss with comparative example]
Next, the melting loss that occurs in this embodiment is compared with the melting loss that occurs in the comparative example.
As described above, in the comparative example, the temperature gradient from the inside of the furnace to the outside of the furnace is different between the water-cooled jacket 100a and the water-cooled jacket 100b (see FIGS. 8A and 8B). (Not shown) also causes uneven distribution of the coating layer (not shown) formed on the inner surface 2a side of the furnace during operation. Therefore, in the comparative example, the melting damage of some of the water-cooled jackets 100a and 100b was accelerated, and the risk of steam explosion due to the leakage in the furnace was high.

On the other hand, in the present embodiment, there is no deviation in the temperature gradient from the inside of the furnace to the outside of the furnace between the first water-cooled jacket 10a and the second water-cooled jacket 10b (see FIGS. 6A and 6B). ), Cooling unevenness is unlikely to occur on the inner surface 2a of the furnace, and unevenness is less likely to occur in the distribution of the slag coating layer formed on the inner surface 2a side of the furnace during operation. Therefore, in the present embodiment, it is unlikely that the melting damage of some of the water-cooled jackets will be accelerated, and the risk of steam explosion is low.

[Effect of embodiment]
As described above, according to the cooling method of the self-heating furnace of the present embodiment, the temperature gradient between the inner surface 2a of the furnace and the cooling water passage 11 of the water cooling jacket 10 is set in the range of 2 to 7 ° C./mm. It is possible to suppress cooling unevenness of the furnace inner surface 2a without increasing the amount of heat removed for cooling the furnace inner surface 2a and without changing the fixed structure 10c of the reaction shaft 2. Therefore, according to the cooling method of the flash smelting furnace 1 of the present embodiment, it is possible to surely maintain the soundness of the furnace body with a small investment amount.

Further, according to the cooling method of the flash smelting furnace of the present embodiment, the temperature gradient is controlled by arranging the refractory 31A between the cooling fins 30 of the second water cooling jacket 10b, so that the cooling unevenness of the inner surface 2a of the furnace is controlled. Can be effectively suppressed.

Further, according to the cooling method of the flash smelting furnace of the present embodiment, the distance from the inner surface 2a of the furnace to the nearest cooling water channel 11 of the first water-cooled jacket 10a and the closest of the inner surface 2a of the furnace to the second water-cooled jacket 10b. Since the distance to the cooling water channel 11 is set to be substantially equal, the temperature gradient from the inside of the furnace to the outside of the furnace can be made substantially the same between the first water cooling jacket 10a and the second water cooling jacket 10b.

Further, according to the cooling method of the flash smelting furnace of the present embodiment, the layout of the cooling water passage 11 of the first water cooling jacket 10a or the cooling fin 30 of the second water cooling jacket 10b is performed without changing the layout of the fixed structure 10c. It is economical because the temperature gradient can be controlled by changing at least one of the sizes of.

Further, according to the cooling structure of the self-melting furnace of the present embodiment, the amount of heat removed for cooling the inner surface 2a of the furnace is not increased, and the fixed structure 10c of the reaction shaft 2 is not changed. It is possible to suppress cooling unevenness on the inner surface 2a. Therefore, it is possible to reliably maintain the soundness of the furnace body with a small investment amount.

Further, according to the cooling structure of the flash smelting furnace of the present embodiment, the distance from the inner surface 2a of the furnace to the nearest cooling water channel 11 of the first water cooling jacket 10a and the closest from the inner surface 2a of the furnace to the second water cooling jacket 10b. Since the distance to the cooling water channel 11 is set to be substantially equal, the temperature distribution from the inside of the furnace to the outside of the furnace can be made substantially the same between the first water-cooled jacket 10a and the second water-cooled jacket 10b.

[Supplementary information on temperature monitoring]
One or a plurality of thermocouples may be arranged on the water-cooled jacket 10 in order to grasp the progress of melting of the cooling fins 30 and the tips of the first water-cooled jackets 10a (hereinafter referred to as "cooling fins 30 and the like"). .. The temperature data measured by the thermocouple may be analyzed using a computer 50 to constantly monitor the progress of melting of the cooling fins 30 and the like. The thermocouple is attached to a base end portion of a predetermined cooling fin 30 or the like provided on the water cooling jacket 10, and the temperature measured at this portion is constantly taken in by a computer installed in a control room (not shown) for monitoring. Will be done. From this temperature, it is possible to grasp the progress state of melting damage of the cooling fins 30 and the like. The computer estimates the life of the cooling fins 30 and the like based on the measured temperature, and warns and notifies the security personnel and the like by sound, light (lamp) alarm, printout, and the like. Based on this, security personnel and the like can avoid long-term suspension of operations by preparing the water-cooled jacket 10 that needs to be replaced in advance. It is also possible to set a predetermined temperature in the computer in advance and to give an alarm prompting the replacement of the water-cooled jacket 10 when the temperature measured by the thermocouple reaches the set temperature.

According to the present embodiment, the difference between the time when the first water-cooled jacket 10a is melted and the time when the second water-cooled jacket 10b is melted can be reduced, so that the thermocouple of one of the water-cooled jackets is omitted. Then, the replacement time of the one water-cooled jacket may be predicted based on the output of the thermocouple of the other water-cooled jacket.

[Other embodiments]
The present invention is not limited to each embodiment, and the components can be modified and embodied without departing from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in each embodiment. For example, some components may be removed from all the components shown in the embodiments. Further, the components of different embodiments may be combined as appropriate.

1 Self-melting furnace 1a Bottom of the furnace 2 Reaction shaft 2a Inner surface of the furnace 3 Setra 4 Uptake 7 Concentrate burner 8 Oxygen-enriched air supply part 9a Skirt part 9b Cylindrical part 10 Water-cooled jacket 10a Water-cooled jacket 10b Water-cooled jacket 10c Fixed structure 11 Cooling water channel 12 Supply port 13 Discharge port 14 Tightening member 20 Jacket body 21 Mounting part 30 Cooling fin 31 Fireproof layer 31A Standard fireproof material 100a Water cooling jacket 100b Water cooling jacket 110 Cooling water channel 300 Cooling fin

Claims (5)

A water-cooled jacket that serves as a side wall of the shaft is attached between the shelf plates, which are fixed structures constituting the shaft of the flash smelting furnace, and the cooling water is supplied to the water channel provided in the water-cooled jacket. In the cooling method of the flash smelting furnace that cools the inner surface of the water-cooled jacket located inside the furnace.
The magnitude of the temperature gradient from the inside of the furnace to the outside of the furnace in the section from the inner surface of the furnace located on the innermost side of the water-cooled jacket to the water channel closest to the water-cooled jacket is within the range of 2 to 7 ° C./mm. A cooling method for a flash smelting furnace, characterized in that it is used. In the method for cooling a flash smelting furnace according to claim 1,
The water-cooled jacket
A plate-shaped first water-cooled jacket mounted between the shelves, which is the fixed structure,
It has a second water-cooled jacket, which is provided with a plurality of fins protruding inward of the furnace and is mounted so as to be located between the shelf board and the first water-cooled jacket.
A method for cooling a flash smelting furnace, which controls the temperature gradient by arranging a refractory material between the fins of the second water-cooled jacket. In the method for cooling a flash smelting furnace according to claim 2.
A method for cooling a flash smelting furnace, wherein the fins of the second water-cooled jacket have a length of 100 to 200 mm, a thickness of 50 to 100 mm, and a distance between the fins of 50 to 100 mm. In the method for cooling a flash smelting furnace according to claim 2 or 3.
The distance between the inner surface of the furnace located on the innermost side of the first water-cooled jacket and the nearest water channel of the first water-cooled jacket, and the innermost side of the second water-cooled jacket. A method for cooling a flash smelting furnace, wherein the distance between the inner surface of the furnace and the nearest water channel of the second water cooling jacket is equal. In the method for cooling a flash smelting furnace according to any one of claims 2 to 4.
It is characterized in that the temperature gradient is controlled by changing at least one of the layout of the water channel of the first water-cooled jacket or the fin size of the second water-cooled jacket without changing the layout of the fixed structure. How to cool the flash smelting furnace.

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