JP7754717B2 - Concentrate burner, flash smelting furnace, and reaction gas introduction method - Google Patents

Description

The present invention relates to a concentrate burner, a flash smelting furnace, and a method for introducing a reactive gas.

A flash smelting furnace is a smelting furnace used for smelting non-ferrous metals such as copper and nickel, and for matte processing. It has a shaft mounted above a reverberatory furnace-type settler, and gas for reaction with the raw materials is blown in from the top of the shaft, utilizing the heat generated by oxidation to instantly oxidize and melt the raw materials. In a flash smelting furnace, the concentrate burner, which supplies the raw materials and reaction gas into the furnace, plays a critical role in determining the performance of the flash smelting furnace. The performance of this concentrate burner determines the reaction efficiency and reaction progress of the raw materials within the reaction shaft, which in turn affects the processing capacity and metal recovery rate of the flash smelting furnace. It is desirable for the reaction within the reaction shaft in a flash smelting furnace to proceed quickly and uniformly at the same reaction progress for all raw materials. For this reason, it is desirable for the raw materials and reaction gas to be mixed uniformly.

To improve the mixing of the raw materials and reaction gas, a known method is to swirl the main airflow supplied from the concentrate burner into the reaction shaft (Patent Document 1). Another known method is to provide an oxygen inlet pipe surrounding the fuel burner inside the tubular concentrate chute, with guide vanes at the opening to supply a swirling flow (Patent Document 2).

Special Publication No. 2010-538162 Japanese Unexamined Patent Publication No. 60-248832

However, the area directly below the concentrate burner where the raw materials are supplied is low in temperature due to the main airflow, making it difficult for the concentrate reaction to proceed. Patent Documents 1 and 2 do not actively generate a swirling flow in this area directly below the raw material supply device, leaving room for improvement.

The present invention was made in consideration of the above problems, and aims to actively promote the mixing of the raw materials and reaction gas supplied into the flash smelting furnace, thereby making the reaction uniform.

The concentrate burner of the present invention is a concentrate burner that supplies raw materials into a flash smelting furnace and also supplies a reactive gas that contributes to a reaction of the raw materials into at least the flash smelting furnace, and comprises: a first cylindrical section that is provided outside a lance and forms a raw material flow path between itself and the lance for supplying the raw materials into the flash smelting furnace; a second cylindrical section that is provided outside the first cylindrical section and forms an annular first gas flow path between itself and the first cylindrical section for supplying the reactive gas into the flash smelting furnace; a third cylindrical section that is provided outside the second cylindrical section and forms an annular second gas flow path between itself and the second cylindrical section for supplying the reactive gas into the flash smelting furnace; and swirl vanes that protrude into the first gas flow path and swirl the reactive gas passing through the first gas flow path , and the time required for the reactive gas to pass between the upper end of the swirl vane and the upper edge of the second cylindrical section is between 0.5 ms and 3.7 ms.

Here, the swirl vanes can be provided on the inner peripheral wall surface of the second cylindrical portion. The swirl vanes can be arranged with a gap between them and the first cylindrical portion. Furthermore, the inclination angle of the swirl vanes with respect to the axial direction of the lance can be in the range of 5° to 20°, and more preferably in the range of 10° to 15°.

Furthermore, the upper end of the swirl vane may be located below the upper edge of the second cylindrical portion, and a region may be provided between the upper end of the swirl vane and the upper edge of the second cylindrical portion to equalize the flow rate of the gas introduced into the first gas flow path. The distance between the upper end of the swirl vane and the upper edge of the second cylindrical portion is preferably 100 mm or more, more preferably 150 mm or more, and even more preferably 200 mm or more.

The flash smelting furnace of the present invention is also equipped with the concentrate burner of the present invention.

Furthermore, the present invention provides a method for introducing a reactive gas, which introduces a reactive gas into a flash smelting furnace together with raw materials fed into the flash smelting furnace through a raw material flow path formed in a concentrate burner, through at least a first gas flow path formed around the raw material flow path and a second gas flow path formed around the first gas flow path, wherein the reactive gas discharged through the first gas flow path is introduced into the flash smelting furnace as a swirling flow, and the reactive gas discharged through the second gas flow path is introduced into the flash smelting furnace while surrounding the swirling flow and suppressing diffusion of the swirling flow, and the method is arranged in a cylindrical part forming the first gas flow path, and the time required for the reactive gas to pass between the upper end of a swirl blade that generates the swirling flow and the upper edge of the cylindrical part is 0.5 ms to 3.7 ms .

The present invention uses swirling blades installed at the lower end of the concentrate burner to promote mixing of the raw materials and reaction gas, thereby making the reaction uniform.

FIG. 1 is a diagram showing a schematic configuration of a flash furnace for copper smelting according to an embodiment. FIG. 2 is a cross-sectional view of a charging portion provided at the tip of a concentrate burner provided in a flash smelting furnace according to an embodiment. FIG. 3 is an enlarged cross-sectional view of the input portion shown in FIG. FIG. 4 is a perspective explanatory view showing the arrangement of the swirl vanes. FIG. 5 is an explanatory diagram of the attachment angle θ of the swirl vane and the flow velocity uniformity region. FIG. 6 is a graph showing an example of a simulation result of the flow velocity distribution at the outlet of the first gas flow passage when no flow velocity uniforming region is provided. FIG. 7 is a graph showing an example of a simulation result of the flow velocity distribution at the outlet of the first gas flow passage when a flow velocity uniforming region with a vertical distance L1b of 100 mm is provided. FIG. 8 is a graph showing an example of the simulation results of the flow velocity distribution at the outlet of the first gas flow passage when a flow velocity uniforming region with a vertical distance L1b of 200 mm is provided. Figure 9(A) is an explanatory diagram showing the results of the reaction simulation when θ = 0°, Figure 9(B) is the results of the reaction simulation when θ = 10°, and Figure 9(C) is the results of the reaction simulation when θ = 15°.

Below, we will explain the concentrate burner of the embodiment based on the drawings.

(Embodiment)
As shown in FIG. 1, the flash smelting furnace 100 comprises a concentrate burner 1 and a furnace body 2. The concentrate burner 1 is a raw material supply device that supplies the raw material concentrate (copper concentrate (CuFeS _{, etc.} )), a main reaction gas, an auxiliary reaction gas, and a dispersion gas (which also contributes to the reaction) into the furnace body 2. The furnace body 2 comprises a reaction shaft 3 where the concentrate and the reaction gas are mixed, a settler 4, and an uptake 5. The main reaction gas and the auxiliary reaction gas are oxygen-enriched air, and the dispersion gas is air or oxygen-enriched air. These reaction gas and dispersion gas disperse and simultaneously oxidize the concentrate, separating it into matte and slag at the bottom of the reaction shaft 3.

Figure 2 is an explanatory diagram showing the input section 10 provided at the tip of the concentrate burner 1. Figure 3 is an enlarged cross-sectional view of the input section 10 shown in Figure 2. The input section 10 inputs raw materials, reaction gas, and dispersion gas into the reaction shaft 3.

The input section 10 of the concentrate burner 1 comprises a lance 11 located at its center and a first cylindrical section 13 located outside the lance 11, forming a raw material flow path 12 between the lance 11 and the first cylindrical section 13. The input section 10 also comprises a second cylindrical section 15a located outside the first cylindrical section 13, forming an annular first gas flow path 14 between the first cylindrical section 13 and the first cylindrical section 13, through which the reaction gas is supplied into the flash smelting furnace 100 (reaction shaft 3). The input section 10 further comprises a third cylindrical section 17a located outside the second cylindrical section 15a, forming an annular second gas flow path 16 between the second cylindrical section 15a and the second cylindrical section 15a, through which the reaction gas is supplied into the flash smelting furnace 100 (reaction shaft 3). The input section 10 also comprises a swirl vane 19 protruding into the first gas flow path 14 and swirling the reaction gas passing through the first gas flow path 14.

The lance 11 is arranged along a central axis AX extending in the vertical direction. The lance 11 includes a third gas flow path 11a located at its center and a fourth gas flow path 11b arranged around the third gas flow path 11a. A reaction auxiliary gas, which is part of the reaction gas, passes through the third gas flow path 11a. A dispersion gas passes through the fourth gas flow path 11b. A hollow truncated conical dispersion cone 111 is provided at the tip (lower end) of the lance 11. A plurality of supply holes 111a are formed on the lower side of the dispersion cone 111, through which the dispersion gas that has passed through the fourth gas flow path 11b is discharged into the reaction shaft 3. In this embodiment, the supply holes 111a are arranged so that the gas discharge direction is normal to the base circle of the dispersion cone 111. However, the supply holes 111a may be arranged so that the gas discharge direction is angled relative to the normal to the base circle of the dispersion cone 111.

The first cylindrical portion 13 is formed by a cylindrical member arranged to surround the lance 11. In this embodiment, the first cylindrical portion 13 is provided as a water-cooled nozzle through which cooling water circulates.

The raw material flow path 12 formed between the lance 11 and the first cylindrical portion 13 supplies the concentrate into the reaction shaft 3.

The second cylindrical portion 15a is provided as part of the inner tank member 15, which is arranged outside the first cylindrical portion 13. The inner tank member 15 has a funnel-shaped portion 15b at its upper portion, which expands in diameter toward the top, and a cylindrical second cylindrical portion 15a connected to the bottom of the funnel-shaped portion 15b. The funnel-shaped portion 15b forms a first air chamber 151 between itself and the first cylindrical portion 13. The first air chamber 151 is connected to the first gas flow path 14. The inner tank member 15 is provided in a detachable manner.

The third cylindrical portion 17a is provided as the inner peripheral wall portion of the cooling jacket 17 provided at the lower end of the input portion 10. Cooling water circulates within the cooling jacket 17. The cooling jacket 17 is located above it and is connected to a funnel-shaped outer tank member 18 that widens in diameter toward the top. Specifically, the cooling jacket 17 is attached to a flange-shaped portion 18a provided at the lower end of the outer tank member 18. The outer tank member 18 forms a second air chamber 181 between itself and the inner tank member 15. The second air chamber 181 is connected to the second gas flow path 16.

The concentrate burner 1 has a first gas supply system 21 and a second gas supply system 22. The first gas supply system 21 branches into a first supply section 21a and a second supply section 21b. The first supply section 21a supplies gas into the first air chamber 151. Meanwhile, the second supply section 21b supplies gas into the second air chamber 181. The first supply section 21a is provided with an adjustment valve 21a1 that adjusts the gas flow rate, thereby adjusting the ratio between the amount of gas supplied into the first air chamber 151 and the amount of gas supplied into the second air chamber 181. The second gas supply system 22 supplies gas into the lance 11. The total amount of gas supplied by the first gas supply system 21 and the second gas supply system 22 can also be adjusted.

In this embodiment, the first supply unit 21a further branches into two paths. The first air chamber 151 has gas inlets 151a in two locations on its upper part, and each is connected to a path branching from the first supply unit 21a. The first air chamber 151 has a larger upper dimension than a lower dimension. When blowing gas into a first air chamber 151 with such a larger upper dimension, it is desirable to provide gas inlets in multiple locations so that the gas is distributed throughout the entire first air chamber 151. Furthermore, it is desirable to provide the multiple gas inlets radially from the center of the first air chamber 151 or symmetrically about the central axis AX. Therefore, in this embodiment, gas inlets 151a are provided in two locations symmetrically about the central axis AX.

Swirl vanes 19 are provided in the first gas flow path 14. The swirl vanes 19 are provided on the inner wall surface 15a1 of the second cylindrical portion 15a so as to protrude into the first gas flow path 14. By providing the swirl vanes 19 on the inner wall surface 15a1 of the second cylindrical portion 15a included in the removable inner tank member 15, cleaning and maintenance work around the swirl vanes 19 becomes easier. The swirl vanes 19 also function as spacers between the first cylindrical portion 13 and the second cylindrical portion 15a. In other words, the swirl vanes 19 also have the function of maintaining the distance between the first cylindrical portion 13 and the second cylindrical portion 15a.

Referring to Figure 3, the swirl vane 19 is positioned with a gap S1 between it and the first cylindrical portion 13. The gap S1 is provided in this manner to accommodate dimensional changes due to thermal expansion of the components.

Now, with reference to Figures 4 and 5, the arrangement of the swirl vanes 19 will be described in more detail. The distance the second cylindrical portion 15a extends in the vertical direction is L1. The swirl vanes 19 are provided in the second cylindrical portion 15a, but the upper ends 19a of the swirl vanes 19 are located below the upper edge 15a3 of the second cylindrical portion 15a. The vertical length of the swirl vanes 19 is L1a. As a result, a region 30 (hereinafter referred to as the "flow velocity uniformity region") that uniforms the flow velocity of the gas introduced into the first gas flow path 14 is provided between the upper ends 19a of the swirl vanes 19 and the upper edge 15a3 of the second cylindrical portion 15a. In other words, the flow velocity uniformity region 30 is provided at the transition position from the funnel-shaped portion 15b to the second cylindrical portion 15a. The flow velocity uniform region 30 is a region indicated by hatching in FIG. 5, in which the inner peripheral wall surface 15a1 of the second cylindrical portion 15a is exposed over the entire periphery.

The vertical distance of the flow velocity uniformity region 30 is L1b. The lower end 19b of the swirl vane 19 coincides with the lower edge 15a4 of the second cylindrical portion 15a. The lower end 19b of the swirl vane 19 does not necessarily have to coincide with the lower edge 15a4, but by aligning it with the lower edge 15a4, it is advantageous in that gas can be discharged without attenuating the momentum of the swirling flow generated by the swirl vane 19.

The lower edge 15a4 of the second cylindrical portion 15a serves as the outlet of the first gas flow path 14. It is desirable that the gas flow rate at the outlet of this first gas flow path 14 be uniform around the entire circumference of the first gas flow path 14, from the perspective of promoting mixing of the raw materials and the reaction gas and uniformizing the reaction. However, in this embodiment, gas is blown into the first air chamber 151 from two gas inlets 151a. Therefore, it is conceivable that the flow rate of the gas flowing from the funnel-shaped portion 15b into the first cylindrical portion 15a will vary.

Therefore, in this embodiment, a flow velocity uniformity region 30 is provided between the upper end 19a of the swirl vane 19 and the upper edge 15a3 of the second cylindrical portion 15a. Here, the effect of providing the flow velocity uniformity region 30 will be explained with reference to Figures 6 to 8.

In this embodiment of the flash smelting furnace 100, the flow velocity of the gas introduced into the second cylindrical section 15a during operation is assumed to be approximately 110 m/s to 130 m/s. Therefore, the simulation was performed under the condition that the average flow velocity of the gas flowing into the flow velocity uniformity region 30 is 120 m/s. The simulation was performed using scFLOW from Software Cradle Co., Ltd. As an example, 12 swirl vanes were installed at equal intervals in the circumferential direction. The horizontal width of the swirl vanes was set to 90% of the width of the gas flow path 14. The length of L1 was set to 500 mm or more and between 0.5 and 2 times the outer diameter of the second cylindrical section 15a. As an example, the angle of the swirl vanes 19 was set to 10°. The average flow velocity here refers to the average value of the flow velocity around the entire circumference of the upper edge 15a3 of the second cylindrical section 15a. The flow velocity of the gas introduced into the second cylindrical portion 15a at an average velocity of 120 m/s is increased in the region where the swirl vanes 19 are provided. This is thought to be because, in the region where the swirl vanes 19 are provided, the gas flow passage area is reduced by the volume of the swirl vanes 19, and therefore the flow velocity of the gas passing between the swirl vanes 19 increases. In this embodiment, the average flow velocity at the outlet of the first gas passage 14 is 124.2 m/s. This average flow velocity refers to the average value of the flow velocity around the entire circumference of the lower edge 15a4 of the second cylindrical portion 15a. During actual operation of the flash smelting furnace 100, the flow velocity of the gas introduced into the second cylindrical portion 15a can be adjusted by the aperture of the regulating valve 21a1.

Figure 6 shows the results of a simulation of a comparative example, specifically, an example of the simulation results of the flow velocity distribution at the outlet of the first gas flow path 14 when no flow velocity uniformity region is provided. In this simulation, the mounting angle θ of the swirl vanes 19 is set to 10°. This also applies to the following simulations. The mounting angle θ is the inclination angle of the swirl vanes 19 with respect to the central axis AX extending in the vertical direction (the mounting angle θ will be described in detail later). Here, the case where no flow velocity uniformity region is provided refers to the case where the swirl vanes 19 are provided across the entire vertical area of the second cylindrical portion 15a. In this case, the variation in flow velocity at the outlet of the first gas flow path 14 is approximately ±2.0% of the average flow velocity of 124.2 m/s.

Specifically, at the point where the flow velocity at the outlet of the first gas flow path 14 was slowest, the difference from the average flow velocity of 124.2 m/s was -2.6%, and at the point where the flow velocity at the outlet of the first gas flow path 14 was fastest, the difference from the average flow velocity of 124.2 m/s was +2.0%. Note that a "- (minus)" indicates a slower flow velocity than the average flow velocity, and a "+ (plus)" indicates a faster flow velocity than the average flow velocity. This also applies to the following explanations.

Next, referring to Figure 7, when the vertical distance L1b of the flow velocity uniformity region 30 is 100 mm, the variation in flow velocity at the outlet of the first gas flow path 14 is approximately ±1.5% of the average flow velocity of 124.2 m/s.

Specifically, at the point where the flow velocity at the outlet of the first gas flow path 14 was slowest, the difference from the average flow velocity of 124.2 m/sec was -1.8%, and at the point where the flow velocity at the outlet of the first gas flow path 14 was fastest, the difference from the average flow velocity of 124.2 m/sec was +1.4%. Thus, by providing the flow velocity uniformity region 30, the variation in flow velocity at the outlet of the first gas flow path 14 was improved.

Next, referring to Figure 8, when the vertical distance L1b of the flow velocity uniformity region 30 is 200 mm, the variation in flow velocity at the outlet of the first gas flow path 14 is approximately ±1% of the average flow velocity of 124.2 m/s.

Specifically, at the location where the flow velocity at the outlet of the first gas flow path 14 was slowest, the difference from the average flow velocity of 124.2 m/s was -1.0%, and at the location where the flow velocity at the outlet of the first gas flow path 14 was fastest, the difference from the average flow velocity of 124.2 m/s was +0.9%. In other words, by increasing the vertical distance L1b of the flow velocity uniformization region 30, further improvement in the variation in flow velocity at the outlet of the first gas flow path 14 was observed. In this way, by increasing the vertical distance L1b, it is possible to improve the variation in flow velocity at the outlet of the first gas flow path 14. For this reason, although simulation results are not shown, the vertical distance L1b of the flow velocity uniformization region 30 may be set to 150 mm, for example, to improve the variation in flow velocity at the outlet of the first gas flow path 14.

The simulation results shown in Figures 7 and 8 suggest that the longer the vertical distance L1b of the flow velocity uniformization region 30, the greater the effect of uniforming the flow velocity. However, when no swirl vanes 19 are provided on the inner peripheral wall surface of the second cylindrical portion 15a, the flow velocity at the outlet of the first gas flow path 14 varies by approximately ±1% of the average flow velocity. Therefore, the upper limit of the effect of the flow velocity uniformization region 30 is approximately ±1% of the average flow velocity, and if the vertical distance L1b = 200 mm that achieves this is set, it is thought that an effect roughly equivalent to that achieved when no swirl vanes 19 are provided can be obtained.

Here, the vertical distance L1b of the flow rate uniformity region 30 is designed to match the size of the flash smelting furnace 100 and the dimensions of the concentrate burner 1, and these dimensions may be changed as appropriate. Therefore, the vertical distance L1b of the flow rate uniformity region 30 needs to be at least 100 mm or more, and although there is no particular upper limit, it can be set to 400 mm or less depending on the various conditions of the flash smelting furnace 100 and the concentrate burner 1.

However, in this case, the vertical length L1a of the swirl vane 19 must be long enough to create the desired swirling flow, so the vertical distance L1b of the flow velocity uniformization region 30 is set within a range that satisfies this condition. For example, if the vertical distance L1 of the second cylindrical portion 15a is 700 mm and the vertical distance L1b of the flow velocity uniformization region 30 is set to 100 mm, the vertical length L1a of the swirl vane 19 will be 600 mm. Similarly, if the vertical distance L1b of the flow velocity uniformization region 30 is set to 400 mm, the vertical length L1a of the swirl vane 19 will be 300 mm. In this case, if an appropriate swirling flow is generated, the vertical distance L1b of the flow velocity uniformization region 30 may be set to 400 mm.

In the above simulation, the average flow velocity of the gas flowing into the flow velocity uniformity region 30 was 120 m/s (the average flow velocity at the outlet of the first gas flow path 14 was 124.2 m/s), but similar trends were observed in other flow velocity ranges.

For example, when the average flow velocity of gas flowing into the flow velocity uniformization region 30 during operation is 110 m/sec, the average flow velocity at the outlet of the first gas flow path 14 is 113.8 m/sec. Under these flow velocity conditions, a simulation was performed with the vertical distance L1b of the flow velocity uniformization region 30 set to 200 mm, yielding the following results: At the location where the flow velocity at the outlet of the first gas flow path 14 was slowest, the difference from the average flow velocity of 113.8 m/sec was -1.0%, and at the location where the flow velocity at the outlet of the first gas flow path 14 was fastest, the difference from the average flow velocity of 113.8 m/sec was +1.2%.

Furthermore, when the average flow velocity of the gas flowing into the flow velocity uniformity region 30 during operation is 130 m/sec, the average flow velocity at the outlet of the first gas flow path 14 is 134.5 m/sec. Under these flow velocity conditions, a simulation was performed with the vertical distance L1b of the flow velocity uniformity region 30 set to 200 mm, and the following results were obtained: At the point where the flow velocity at the outlet of the first gas flow path 14 was slowest, the difference from the average flow velocity of 134.5 m/sec was -0.8%, and at the point where the flow velocity at the outlet of the first gas flow path 14 was fastest, the difference from the average flow velocity of 134.5 m/sec was +1.1%.

Here, since the flow rate is considered to be uniformed when the gas passes through the area of the second cylindrical section 15a where the swirl vanes 19 are not provided, it is considered necessary for the gas to pass through such an area for a predetermined time. Specifically, the time it takes for the gas to pass between the upper end 19a of the swirl vanes 19 and the upper edge 15a3 of the second cylindrical section 15a, i.e., the time it takes to pass through the flow rate uniformity area 30, can be set between 0.5 ms and 3.7 ms.

For example, when the vertical distance L1b of the flow rate uniformity region 30 is 100 mm (= 0.1 m), the average flow rate of the gas in the flow rate uniformity region 30 is 130 m/s, the fastest flow rate expected in operating conditions. Under these conditions, it takes 0.1 (m) ÷ 130 (m/s) = 0.77 ms for the gas to pass through the flow rate uniformity region 30.

Furthermore, when the vertical distance L1b of the flow velocity uniforming region 30 is 400 mm (= 0.4 m), the average flow velocity of the gas in the flow velocity uniforming region 30 is 110 m/s, the slowest flow velocity expected in operating conditions. Under these conditions, it takes 0.4 (m) ÷ 110 (m/s) = 3.63 ms for the gas to pass through the flow velocity uniforming region 30.

In this way, the vertical distance L1 of the flow velocity uniformity region 30 may be determined by the time it takes to pass through the flow velocity uniformity region 30.

In this way, the extent of the flow velocity uniformity region 30 can be set based on at least either distance or flow velocity.

By making the outlet flow velocity of the first gas flow path 14 uniform around the entire circumference, mixing of the raw material and the reaction gas can be further promoted, making the reaction uniform. This is particularly effective when blowing gas into the air chamber 151 from one or two locations, as the flow velocity of the gas flowing from the funnel-shaped portion 15b into the second cylindrical portion 15a tends to vary.

Next, referring again to Figures 4 and 5, and also to Figure 9, the mounting angle θ of the swirl vane 19 will be explained. The mounting angle θ of the swirl vane 19 is the inclination angle relative to the axial direction of the lance 11, i.e., the central axis AX extending in the vertical direction. Note that in Figure 5, axis AX1 indicates an axis parallel to the central axis AX, and when the longitudinal direction of the swirl vane 19 coincides with the direction along axis AX1, the mounting angle θ is expressed as 0°.

Such an installation angle θ can be set in the range of 5° to 20°, and it is preferable to set it in the range of 10° to 15°.

Figures 9(A) to 9(C) show the results of reaction simulations within the reaction shaft 3 for different installation angles θ of the swirl vanes 19. Figure 9(A) shows the results of the reaction simulation when θ = 0°, Figure 9(B) shows the results of the reaction simulation when θ = 10°, and Figure 9(C) shows the results of the reaction simulation when θ = 15°.

In each of Figures 9(A) to 9(C), the reference symbol AR indicates the reaction region within the furnace. The lowest point of this reaction region AR can be used as one of the indicators for evaluating the state of the reaction within the furnace, known as the reaction point height. In other words, when the reaction point height is high, the raw material and reaction gas are actively being mixed in the region near the input port 10, and it can be evaluated that the reaction state within the furnace is good.

Figure 9(A) shows the case when θ = 0°. If the reaction point height at this time is h0, then the reaction point height h1 at θ = 10° shown in Figure 9(B) is higher than the reaction point height h0. Furthermore, the reaction point height h2 at θ = 15° shown in Figure 9(C) is higher than the reaction point height h1. As can be seen, the reaction point height increases as the mounting angle θ increases. In other words, as the mounting angle θ increases, the diffusion of the raw material is promoted, and the mixing of the raw material and the reaction gas is actively promoted. Because the diffusion of the raw material is promoted as the mounting angle θ increases, even when the mounting angle θ is increased beyond 0°, for example, at θ = 5°, the diffusion of the raw material and the mixing of the raw material and the reaction gas can be promoted. Furthermore, the mounting angle θ may be increased beyond θ = 15°, for example, at θ = 20°, to promote the diffusion of the raw material and the mixing of the raw material and the reaction gas.

As described above, it was found that the diffusion of the raw materials is promoted as the mounting angle θ of the swirl vane 19 is increased. However, there is a concern that increasing the mounting angle θ of the swirl vane 19 makes it easier for particles contained in the raw materials to move toward the wall surface of the flash smelting furnace 100, increasing the possibility of collision with the furnace wall. However, the concentrate burner 1 of this embodiment includes the first gas passage 14 and the second gas passage 16 located outside it, and only the reaction gas passing through the first gas passage 14 is made to swirl. That is, the reaction gas passing through the first gas passage 14 swirls, but the reaction gas passing through the second gas passage 16 is discharged toward the bottom of the flash smelting furnace 100. Moreover, the reaction gas passing through the second gas passage 16 is discharged so as to surround the swirling reaction gas. Therefore, the diffusion of the reaction gas discharged from the first gas passage 14 as a swirling flow is suppressed by the reaction gas discharged through the second gas passage 16. As a result, particles in the raw material are less likely to move toward the wall surface of the flash smelting furnace 100.

In addition, this phenomenon of particles in the raw materials moving toward the wall of the flash smelting furnace 100 can be suppressed by adjusting the amount of dispersion gas supplied from the fourth gas flow path 11b through the supply hole 111a provided in the dispersion cone 111.

The likelihood of particles colliding with the wall surface (furnace wall) inside the furnace can be evaluated by the wall collision particle ratio. The wall collision particle ratio is the ratio of the amount of particles that collide with the furnace wall and are trapped relative to the amount of raw material charged into the furnace. The furnace wall is primarily the wall surface of the reaction shaft 3.

Here, an example of a simulation result in which the wall-impingement particle ratio was calculated is shown. The simulation was performed using ANSYS's general-purpose thermal fluid software, FLUENT. In the simulation, the copper concentrate charging rate (t/h) was the same for all cases, and the sum of the airflow rates (dispersion gas volume) of the first gas flow path 14, the second gas flow path 16, the third gas flow path 11a, and the fourth gas flow path 11b (hereinafter referred to as the total airflow rate) was constant. The sum of the airflow rates of the first gas flow path 14 and the second gas flow path 16 was set to be 90% or more of the total airflow rate, and the ratio of the airflow rates of the first gas flow path 14 and the second gas flow path 16 was set to approximately 1:1. When the amount of dispersion gas was varied, the airflow rate of the second gas flow path 16 was increased to compensate for the decrease in the amount of dispersion gas, thereby maintaining the total airflow rate constant. Below, the wall-collision particle ratio when the mounting angle θ of the swirl vane 19 is 0°, 10°, and 15° is shown, but the amount of dispersion gas is uniformly set to 40 ^Nm3 /min at all mounting angles θ. As a result, for example, the wall-collision particle ratio when the mounting angle θ of the swirl vane 19 is 0° is 10.9%, and the wall-collision particle ratio when the mounting angle θ of the swirl vane 19 is 10° is 11.6%. Furthermore, the wall-collision particle ratio when the mounting angle θ of the swirl vane 19 is 15° is 14.6%. Thus, the simulation showed that the wall-collision particle ratio increases as the mounting angle θ of the swirl vane 19 increases. Note that the numerical value of the wall-collision particle ratio is the average value of multiple simulation results.

Next, the simulation results are shown in which the amount of dispersion gas was reduced as the mounting angle θ of the swirl vanes 19 increased. By setting the amount of dispersion gas to 38.5 Nm ³ /min, which is less than 40 Nm ³ /min, when the mounting angle θ of the swirl vanes 19 was 10°, the wall-collision particle ratio was reduced to 11.2%. Furthermore, by setting the amount of dispersion gas to 35 Nm ³ /min, which is less than 40 Nm ³ /min, when the mounting angle θ of the swirl vanes 19 was 15°, the wall-collision particle ratio was reduced to 11.4%. Thus, by adjusting the amount of dispersion gas, an improvement in the wall-collision particle ratio can be expected. For example, even when the mounting angle θ is set to θ = 20°, which is greater than θ = 15°, adjusting the amount of dispersion gas accordingly can promote the diffusion of raw materials and the mixing of raw materials with the reaction gas while suppressing an increase in the wall-collision particle ratio. However, when θ exceeds 20°, a significant reduction in the amount of dispersion gas is required to suppress an increase in the proportion of particles colliding with the wall, and this tends to cancel out the effect of increasing the reaction points due to the swirling air flow through the inner cylinder, so it is desirable to set the upper limit of the installation angle of the swirl blades to 20°. Note that a similar tendency was observed in simulations in which the amount of raw material charged into the furnace was changed.

This makes it possible to maintain the same ratio of particles colliding with the wall surface regardless of the mounting angle θ of the swirl vanes 19. The amount of the reaction gas passing through the second gas flow passage 16 is increased to compensate for the reduction in the dispersion gas, thereby adjusting the total amount of the reaction gas.

In this way, by adjusting the amount of dispersion gas, it is possible to increase the reaction point height while maintaining the proportion of particles colliding with the wall.

According to the concentrate burner 1 of this embodiment, the reaction gas passing through the first gas passage 14 is swirled, which actively promotes mixing of the raw material and the reaction gas and makes the reaction uniform. In the flash smelting furnace 100, the total blast volume may be adjusted depending on the amount of material charged into the furnace. For example, when the amount of material charged decreases, the total blast volume is reduced for heat balance reasons. In this case, the amount of reaction gas passing through the first gas passage 14 is basically kept constant, and the amount of reaction gas passing through the second gas passage 16 is reduced. However, if the amount of reaction gas passing through the second gas passage 16 is reduced too much, it becomes easier for mold to adhere to the periphery of the third cylindrical portion 17a, and disturbances in the air flow are likely to occur. Therefore, a lower limit may be set for the amount of reaction gas passing through the second gas passage 16. Therefore, depending on the charging amount and the grade of the raw material, the amount of the reactive gas passing through the first gas passage 14 may be reduced so that the amount of the reactive gas passing through the second gas passage 16 does not fall below the lower limit. If the amount of the reactive gas passing through the first gas passage 14 is reduced, it is expected that the effect of dispersing the raw material by the reactive gas passing through the first gas passage 14 will be reduced. Therefore, by providing a swirl blade 19 protruding from the first gas passage 14 as in the concentrate burner 1 of this embodiment, it is possible to actively promote mixing of the raw material and the reactive gas.

The above-described embodiment is a preferred example of the present invention. However, it is not limited to this, and various modifications are possible within the scope of the present invention.

REFERENCE SIGNS LIST 1 concentrate burner 2 furnace body 3 reaction shaft 4 settler 5 uptake 11 lance 12 raw material flow path 13 first cylindrical portion 14 first gas flow path 15 inner tank member 15a second cylindrical portion 16 second gas flow path 17 cooling jacket 18 outer tank member 19 swirl vane

Claims (10)

A concentrate burner that supplies raw materials into a flash smelting furnace and also supplies a reaction gas that contributes to a reaction of the raw materials into at least the flash smelting furnace,
a first cylindrical portion provided outside the lance and forming a raw material flow path between the lance and the first cylindrical portion for supplying the raw material into the flash smelting furnace;
a second cylindrical portion provided outside the first cylindrical portion and forming, between the first cylindrical portion and the second cylindrical portion, a first annular gas flow path for supplying the reaction gas into the flash smelting furnace;
a third cylindrical portion provided outside the second cylindrical portion and forming, between the third cylindrical portion and the second cylindrical portion, an annular second gas flow path for supplying the reaction gas into the flash smelting furnace;
a swirl vane that protrudes into the first gas flow path and swirls the reactant gas passing through the first gas flow path;
a funnel-shaped portion having an inclined surface that expands in diameter upward, the upper edge of the second cylindrical portion being connected to a lower end of the inclined surface;
a flow velocity uniforming region formed between an upper end of the swirl vane and the upper edge of the second cylindrical portion, for uniforming the flow velocity of the reactant gas introduced into the first gas flow path;
The dimension of the flow rate uniforming region along the axial direction of the second cylindrical portion is 100 mm or more and 400 mm or less, and the time it takes for the reaction gas passing through the first gas flow path to pass through the flow rate uniforming region is between 0.5 ms and 3.7 ms. The concentrate burner according to claim 1 , wherein the swirl vanes are provided on an inner peripheral wall surface of the second cylindrical portion. The concentrate burner according to claim 2 , wherein the swirl vane is disposed with a gap between it and the first cylindrical portion. 4. The concentrate burner according to claim 1, wherein the angle of inclination of the swirl vanes relative to the axial direction of the lance is in the range of 5° to 20°. 5. The concentrate burner according to claim 4 , wherein the angle of inclination of said swirl vanes relative to the axial direction of said lance is in the range of 10 to 15 degrees. A concentrate burner as described in claim 1, wherein the distance along the axial direction of the second cylindrical portion between the upper end of the swirl vane and the upper edge of the second cylindrical portion is 100 mm or more. 7. The concentrate burner according to claim 6 , wherein the distance between the upper end of the swirl vane and the upper edge of the second cylindrical portion along the axial direction of the second cylindrical portion is 150 mm or more. 8. The concentrate burner according to claim 7 , wherein the distance along the axial direction of the second cylindrical portion between the upper end of the swirl vane and the upper edge of the second cylindrical portion is 200 mm or more. A flash smelting furnace comprising a concentrate burner according to any one of claims 1 to 8 . A method for introducing a reactive gas into a flash smelting furnace through at least a first gas flow path formed around a raw material flow path formed in a concentrate burner and a second gas flow path formed around the first gas flow path, together with raw materials charged into the flash smelting furnace through the raw material flow path formed in the concentrate burner, comprising:
the reactive gas discharged through the first gas flow passage is introduced into the flash smelting furnace as a swirling flow, and the reactive gas discharged through the second gas flow passage is introduced into the flash smelting furnace while surrounding the swirling flow and suppressing diffusion of the swirling flow,
a funnel-shaped section having an inclined surface whose diameter increases upward, the funnel-shaped section having an upper edge connected to a lower end of the inclined surface, the funnel-shaped section being disposed within a cylindrical section forming the first gas flow path, the funnel-shaped section having an inclined surface whose diameter increases upward, the funnel-shaped section having an upper edge connected to a lower end of the inclined surface, the funnel-shaped section being disposed within the first gas flow path ... being disposed within the first gas flow path, the funnel-shaped section having an inclined surface