Multi-stage injection method for antimony concentrate side-blowing reinforced smelting

Abstract

The invention discloses a multi-stage injection method for side-blown reinforced smelting of antimony concentrate, which relates to the technical field of non-ferrous metallurgy and comprises the following steps: a, a charging and preheating stage: conveying antimony concentrate, flux, fuel and other auxiliary materials into a smelting furnace, and injecting by adopting a low-speed and small-quantity gun; b, an intensified smelting stage: after charging is completed, executing when a large amount of materials are melted and main oxidation reaction occurs, and adopting high-speed and multi-gun collaborative injection; c, a stabilizing and refining stage: after the main oxidation reaction tends to be stable and the components of a molten pool tend to be stable, performing injection by adopting a medium-speed and decrement spray gun; and for each stage, preset and different injection parameter combinations are adopted. According to the method, the smelting process is divided into different stages, and the optimal injection parameter combination is matched for each stage, so that the comprehensive technical effects of improving the antimony direct recovery rate, reducing returned materials, reducing energy consumption and prolonging the service life of a furnace lining are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-ferrous metallurgy, in particular to a multi-stage blowing method for side-blown intensified smelting of antimony concentrate. BACKGROUND

[0002] Antimony smelting is a key link for extracting antimony metal. At present, the fire method is mainly used in industrial antimony smelting, of which the blast furnace smelting and the oxygen-enriched side-blown bath smelting are the representatives. Although the traditional blast furnace smelting process is mature, it has inherent defects, such as uneven airflow distribution in the furnace, difficulty in accurately controlling oxygen potential and furnace temperature, resulting in large metal oxidation loss and volatilization loss, and the direct recovery rate of antimony is usually only about 77.5%, a large amount of antimony enters the dust system, increasing the complexity and cost of subsequent processing.

[0003] As an alternative upgrading technology, oxygen-enriched side-blown bath smelting has attracted much attention due to its high efficiency and low carbon potential, and is currently in the pilot experiment stage. However, in the prior art, the side-blown smelting generally adopts a single and constant blowing system. This operation mode also exposes technical defects, mainly in that it is difficult to dynamically and accurately control the oxygen potential, which is the core variable in the smelting process. When the oxygen potential is too high, antimony sulfide will be over-oxidized to high-valence antimony tetroxide or antimony pentoxide, which has a low vapor pressure and is easy to enter the slag phase, resulting in an increase in the antimony content of the slag and a significant reduction in the direct recovery rate of the main metal. When the oxygen potential is too low, it is easy to promote the generation of antimony matte and antimony alloy, which need to be returned to the smelting furnace as return materials, not only occupying the furnace capacity and increasing unnecessary material circulation and energy consumption, but also reducing the overall production efficiency. In addition, the single blowing system cannot adapt to the dynamic demand for smelting pool stirring intensity at each stage of the smelting process, often leading to uneven mixing of the smelting pool, low mass and heat transfer efficiency, and aggravating the erosion of the furnace lining, shortening the service life of the furnace. SUMMARY

[0004] The purpose of the present application is to provide a multi-stage blowing method for side-blown intensified smelting of antimony concentrate to solve the problems raised in the background art.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: a multi-stage blowing method for side-blown intensified smelting of antimony concentrate, comprising: The smelting process is divided into at least three consecutive stages in time sequence, which are: a, charging and preheating stage: executed when antimony concentrate and auxiliary materials such as flux and fuel are delivered into the smelting furnace, low-speed and small amount of gun blowing is adopted, and the blowing speed is controlled in the interval of 80 m / s to 120 m / s; b. Intensified smelting stage: After the addition of materials is completed, the materials begin to melt in large quantities and the main oxidation reaction occurs. High-speed, multi-gun coordinated injection is adopted, and the injection speed is increased to the range of 150 m / s to 200 m / s; c. Stabilization and refining stage: After the main oxidation reaction tends to be stable and the molten pool composition tends to be stable, it is carried out, and the medium-speed, reduced-volume spray gun is used for spraying, and the spraying speed drops back to the range of 120 m / s to 180 m / s; For each of the stages, a preset and different combination of blowing parameters is adopted, wherein the combination of blowing parameters includes the blowing speed and the number of enabled spray guns.

[0006] Furthermore, in the feeding and preheating stage, the blowing speed is preferably 100 m / s, and the number of spray guns is preferably 1-2. The combination of low-speed blowing and a small number of spray guns helps to stabilize the atmosphere in the furnace and reduce material splashing and dust loss.

[0007] Furthermore, in the enhanced smelting stage, the blowing speed is preferably 200 m / s, the number of spray guns is preferably 4 or more, and 4 or more spray guns are operated jointly. The enhanced smelting stage adopts high-speed, multi-gun blowing, which can significantly improve the stirring efficiency and reaction rate, accelerate the formation of the molten pool and homogenize the composition.

[0008] Furthermore, during the stabilization and refining stage, the number of spray guns can be reduced to 2. Reducing the number of spray guns during the stabilization and refining stage reduces the stirring intensity, which helps to reduce slag splashing and scouring of the furnace lining.

[0009] Furthermore, in each of the stages, spray guns of different diameters are flexibly selected according to the requirements of different smelting stages. Specifically, a larger diameter spray gun is selected in the intensive smelting stage to improve the stirring capacity, and a smaller diameter spray gun is selected in the feeding and preheating stage and the stabilization and refining stage to reduce splashing and scouring. The flexible selection of spray guns of different diameters according to the requirements of different stages enhances the adaptability of the blowing system.

[0010] Furthermore, the spray gun with a larger diameter is a spray gun with a diameter of 44 mm, and the spray gun with a smaller diameter is a spray gun with a diameter of 30 mm.

[0011] Furthermore, in the enhanced smelting stage, under high-speed blowing conditions, the air flow field is adjusted by appropriately increasing the distance between adjacent nozzles, thereby suppressing splashing while maintaining the stirring intensity.

[0012] Furthermore, the spacing between adjacent nozzles is increased by 10-15%, and the airflow field is optimized by adjusting the spacing, thereby enhancing the controllability of the operation.

[0013] Furthermore, the blowing parameter combination also includes the blowing flow rate and blowing angle of the spray gun. Incorporating the blowing flow rate and blowing angle into the blowing parameter combination makes the blowing system more perfect, and the coordinated control of multiple parameters can better optimize the smelting process.

[0014] Furthermore, the method also includes real-time monitoring of parameters such as oxygen potential and temperature in the furnace during the smelting process, and dynamically adjusting the injection parameters based on the monitoring results. By real-time monitoring and dynamic adjustment of the injection parameters, it can better adapt to changes in the smelting process.

[0015] In the above technical solution, the technical effects and advantages provided by the present invention are: 1. Significantly improved antimony direct recovery: Through precise control of the oxygen potential at each stage, rapid antimony oxidation is promoted in the intensification stage, volatilization loss of antimony sulfide is suppressed in the stabilization stage, and the formation of antimony matte and antimony alloy is avoided throughout the entire process. This increases the antimony direct recovery rate from 77.5% in traditional blast furnace smelting methods to over 96.8%, and effectively reduces the antimony content in the slag. 2. Significant reduction in return rate: The optimized smelting atmosphere effectively suppresses the formation of intermediate products such as antimony matte, reducing the return rate by more than 60%, significantly improving equipment utilization and production process continuity; 3. Outstanding environmental benefits and reduced subsequent treatment costs: Precise oxygen potential control significantly reduces the total amount of smoke dust generated, especially optimizing the volatilization behavior of antimony-containing phases, reducing the processing load of subsequent flue gas purification systems and reducing environmental protection management costs; 4. Significantly extended furnace lining life: By adopting a "soft" spray mode with a medium-speed, reduced-volume spray gun during the stabilization and refining stages, the severe scouring and erosion of slag on refractory materials is effectively reduced, and the service life of the furnace lining is expected to be extended by more than 30%; 5. Improved energy efficiency and optimized production cycle: The multi-stage injection strategy significantly improves the stirring efficiency and heat and mass transfer rate of the molten pool, reducing the overall energy consumption per unit product by approximately 13.6% and shortening the average smelting cycle by approximately 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0017] Figure 1 Schematic diagram of three consecutive stages of the present invention; Figure 2 This is a gas-liquid two-phase distribution cloud diagram of the 44mm spray gun of the present invention under the working condition of a spraying speed of 100m / s; Figure 3 The gas-liquid two-phase distribution nephogram of the 30mm lance of the present application under the working condition of a blowing speed of 100m / s; Figure 4 The curve graph of the influence of different oxygen lance diameters under the same speed on the average speed of the molten pool section of the present application; Figure 5 The gas-liquid two-phase distribution nephogram comparison graph under different blowing speeds of the present application; Figure 6 The molten pool internal speed field distribution nephogram comparison graph under different blowing speeds of the present application; Figure 7 The curve graph of the influence of different blowing speeds on the monitoring section average speed of the present application; Figure 8 The bubble shape change graph of the present application with double nozzles; Figure 9 The bubble shape change graph of the present application with four nozzles; Figure 10 The curve graph of the influence of different nozzle numbers under the same blowing flow condition on the monitoring section average speed of the molten pool of the present application. DETAILED DESCRIPTION

[0018] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to the drawings.

[0019] The present application provides a multi-stage blowing method for side blowing intensified smelting of antimony concentrate, such as Figure 1 The present application provides a multi-stage blowing method for side blowing intensified smelting of antimony concentrate, such as The smelting process is divided into at least three continuous stages in time sequence, which are: a, charging and preheating stage: it is executed when antimony concentrate and auxiliary materials such as flux and fuel are delivered into the smelting furnace, low speed and small amount of lance blowing is adopted, the blowing speed is controlled in the interval of 80m / s to 120m / s, the blowing speed is preferably 100m / s, the number of lances is preferably 1-2, the combination of low speed blowing and small amount of lances helps to stabilize the furnace atmosphere, reduce material splashing and dust loss, and maintain the basic reaction atmosphere in the furnace, creating conditions for subsequent reactions; b, intensified smelting stage: it is executed when the material starts to melt and the main oxidation reaction occurs after the charging is completed, high speed and multi-lance collaborative blowing is adopted, the blowing speed is increased to the interval of 150m / s to 200m / s, the blowing speed is preferably 200m / s, the number of lances is preferably 4 or more, 4 or more lances are operated jointly, high speed and multi-lance blowing is adopted in the intensified smelting stage, which produces strong gas-liquid turbulent flow and stirring effect, accelerates the formation of molten pool, and ensures the homogenization of components; c. Stabilization and refining stage: After the main oxidation reaction tends to be stable and the molten pool composition tends to be stable, it is carried out. A medium-speed, reduced-volume spray gun is used. The spray speed drops back to the range of 120 m / s to 180 m / s. The number of spray guns can be reduced to 2. Reducing the number of spray guns and the stirring intensity in the stabilization and refining stage helps to reduce slag splashing and scouring of the furnace lining. For each of the stages, a preset and different combination of blowing parameters is adopted, wherein the combination of blowing parameters includes the blowing speed and the number of enabled spray guns.

[0020] In each of the stages, spray guns of different diameters are flexibly selected according to the requirements of different smelting stages. Specifically, a larger diameter spray gun is selected in the intensive smelting stage to improve the stirring capacity, and a smaller diameter spray gun is selected in the feeding and preheating stage and the stabilization and refining stage to reduce splashing and scouring. The flexible selection of spray guns of different diameters according to the requirements of different stages enhances the adaptability of the blowing system.

[0021] The spray gun with the larger diameter is a spray gun with a diameter of 44 mm, and the spray gun with the smaller diameter is a spray gun with a diameter of 30 mm.

[0022] In the enhanced smelting stage, under high-speed blowing conditions, the air flow field is adjusted by appropriately increasing the distance between adjacent nozzles, thereby suppressing splashing while maintaining the stirring intensity.

[0023] The distance between adjacent nozzles is increased by 10-15%. By adjusting the distance, the airflow field is optimized, thereby enhancing the controllability of the operation.

[0024] The blowing parameter combination also includes the blowing flow rate and blowing angle of the spray gun. Incorporating the blowing flow rate and blowing angle into the blowing parameter combination makes the blowing system more perfect, and the coordinated control of multiple parameters can better optimize the smelting process.

[0025] The method also includes real-time monitoring of parameters such as oxygen potential and temperature in the furnace during the smelting process, and dynamically adjusting the injection parameters based on the monitoring results. By real-time monitoring and dynamic adjustment of the injection parameters, it is possible to better adapt to changes in the smelting process.

[0026] Example 1: Parameter optimization study based on computational fluid dynamics (CFD) This paper first numerically simulated the gas-liquid two-phase flow behavior in a side-blown smelting furnace using the Euler-Euler multiphase flow model, aiming to theoretically verify and optimize key injection parameters. Ultimately, a 5 million grid size was chosen to balance computational accuracy and efficiency.

[0027] 1. Analysis and comparison of the influence of spray gun diameter Figure 2 、 Figure 3 and Figure 4 : Setting: The spray velocity is fixed at 100m / s, and the two diameter spray guns of 30mm and 44mm are compared.

[0028] Conclusion: The 44mm spray gun has significantly greater stirring capacity and is suitable for the intensive melting stage, which requires rapid mixing and reaction. The 30mm spray gun provides more stable stirring and is suitable for the charging or stabilization stages, which prevent splashing and reduce lining erosion. This provides the theoretical basis for the technical concept of using different spray gun diameters in different stages of the present invention.

[0029] 2. Analysis and comparison of the impact of injection speed Figure 5 、 Figure 6 and Figure 7 : Setup: Compare three jet velocities: 100 m / s, 150 m / s and 200 m / s.

[0030] Conclusion: High-speed jetting (e.g., 200 m / s) maximizes stirring efficiency, while low-speed jetting (e.g., 100 m / s) effectively controls splashing. This provides theoretical support for the present invention's technical concept of adjusting the jetting speed in stages.

[0031] 3. Analysis and comparison of the impact of the number of spray guns Figure 8 、 Figure 9 and Figure 10 : Setting: Fixed single-nozzle flow rate, comparing the working conditions of 1, 2, and 4 nozzles.

[0032] Conclusion: The coordinated operation of multiple nozzles significantly enhances the overall stirring effect. Therefore, a dynamic adjustment strategy of using four nozzles during the intensification phase and two nozzles during the stabilization phase can achieve the best balance between increasing reaction rate and controlling stability.

[0033] Example 2: Pilot production verification Experimental groups: In order to verify the actual effect of the method of the present invention, a pilot production comparison was carried out between the present invention group and two comparative examples (simulating the traditional blast furnace process and the conventional single-system side-blowing process, respectively).

[0034] Comparative Example 1 (traditional blast furnace process): Process description: Conventional blast furnace is used for smelting. Due to the limitation of equipment structure, it is impossible to accurately control the oxygen-coal ratio and furnace atmosphere.

[0035] Process results: record the direct antimony recovery rate and the antimony content in the slag.

[0036] Comparative Example 2 (conventional single system side blowing process): Process description: The same side-blown melting furnace as the present invention is used, but a constant single-blow system is used for the entire melting cycle.

[0037] Spraying parameters: Two 44mm spray guns were used throughout the process, with a spraying speed of 120 m / s.

[0038] The present invention group (multi-stage blowing method): Process description: Strictly follow the multi-stage blowing method described in the present invention.

[0039] Injection parameters: Feeding stage (30 minutes): Use a 30mm spray gun with a spray speed of 100 m / s.

[0040] Intensified smelting stage (60 minutes): Activate four 44mm spray guns with a spray speed of 180 m / s.

[0041] Stabilization and refining phase (90 minutes): Two 44mm spray guns are used with a spray speed of 140 m / s.

[0042] Experimental results and analysis: The key performance indicators of the three groups of experiments were collected and analyzed, and the results are summarized in the following table: Key Performance Indicators Comparative Example 1 (Blast Furnace) Comparative Example 2 (Conventional Side Blowing) The present invention group Antimony direct recovery rate (%) 77.5 92.5 ≥98.5 Antimony content in slag (%) > 2.0 ~1.5 ≤0.4 Return rate (relative value reduction) - - >60% Comprehensive energy consumption (relative value reduction) - - ~13.6% Average melting cycle (relatively shortened) - - ~20% Experimental data show that the group of the present invention is significantly better than the control group of the traditional single blowing method in all key performance indicators.

[0043] Comparative Example 1 (blast furnace): The direct recovery rate of antimony in the method of the present invention (≥98.5%) is more than 20 percentage points higher than that of the blast furnace (77.5%), and the antimony content in the slag (≤0.4%) is also much lower than that of the blast furnace. This conclusively proves the great advantage of the present invention in using a side-blown furnace to accurately control the oxygen potential and reaction process.

[0044] Comparison Example 2 (conventional side-blowing): Even using the same furnace, the multi-stage dynamic injection strategy of the present invention increases the direct antimony recovery rate from 92.5% to over 98.5%, reduces the antimony content in the slag by approximately 73%, and significantly optimizes the return rate, energy consumption, and smelting cycle. This fully demonstrates that the core innovation of the present invention—"staged, multi-parameter coordinated control"—is the key to achieving this technological breakthrough.

[0045] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A multi-stage injection method for side-blowing enhanced smelting of antimony concentrate, characterized in that: include: The smelting process is divided into at least three consecutive stages in chronological order, namely: a. Charging and preheating stage: This is performed when antimony concentrate, flux, fuel and other auxiliary materials are transported into the smelting furnace. Low-speed, small-volume gun spraying is used, and the spraying speed is controlled within the range of 80 m / s to 120 m / s. b. Intensified smelting stage: After the addition of materials is completed, the materials begin to melt in large quantities and the main oxidation reaction occurs. High-speed, multi-gun coordinated injection is adopted, and the injection speed is increased to the range of 150 m / s to 200 m / s; c. Stabilization and refining stage: After the main oxidation reaction tends to be stable and the molten pool composition tends to be stable, it is carried out, and the medium-speed, reduced-volume spray gun is used for spraying, and the spraying speed drops back to the range of 120 m / s to 180 m / s; For each of the stages, a preset and different combination of blowing parameters is adopted, wherein the combination of blowing parameters includes the blowing speed and the number of enabled spray guns.

2. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: During the feeding and preheating stage, the blowing speed is preferably 100 m / s, and the number of spray guns is preferably 1-2.

3. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: In the enhanced smelting stage, the injection speed is preferably 200 m / s, and the number of injection guns is preferably 4 or more, and 4 or more injection guns are operated in combination.

4. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: During the stabilization and refining phase, the number of lances can be reduced to two.

5. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: In each of the stages, spray guns of different diameters are flexibly selected according to the requirements of different smelting stages. Specifically, a larger diameter spray gun is selected in the intensive smelting stage, and a smaller diameter spray gun is selected in the charging and preheating stage and the stabilization and refining stage.

6. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 5, characterized in that: The spray gun with the larger diameter is a spray gun with a diameter of 44 mm, and the spray gun with the smaller diameter is a spray gun with a diameter of 30 mm.

7. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: In the enhanced smelting stage, under high-speed blowing conditions, the air flow field is adjusted by appropriately increasing the distance between adjacent nozzles, thereby suppressing splashing while maintaining the stirring intensity.

8. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 7, characterized in that: The spacing between adjacent nozzles is increased by 10–15%.

9. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: The spray parameter combination also includes the spray flow rate and the spray angle of the spray gun.

10. The multi-stage injection method for side-blowing enhanced smelting of antimony concentrate according to claim 1, characterized in that: The method also includes real-time monitoring of parameters such as oxygen potential and temperature in the furnace during the smelting process, and dynamically adjusting the injection parameters based on the monitoring results.

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