A system for melting dross in the throat of a smelting fumace for tin by local high temperature
Patent Information
- Application Number
- CN202522364954.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-10-20
- Estimated Expiration
- 2035-11-07
AI Technical Summary
这导致炉膛背压急剧上升，为维持必要还原气氛和鼓风量，必须大幅提高鼓风压力，显著增加能耗
[0018](1)设备利用率高：本实用新型通过三级阶梯式干预，利用富氧天然气在结渣表面与一氧化碳剧烈燃烧在咽喉结渣表面形成1300-1350℃的局部高温，熔化大部分咽喉结渣，避免了结渣快速增厚导致的被迫停炉，本实用新型将烟化炉在咽喉结渣威胁下的有效作业时间提高了300％，极大减少了非计划停炉次数和时长，显著提升了设备的生产效率和产能利用率；
Smart Images
Figure CN224872899U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of non-ferrous metal smelting technology, specifically to a system for slag formation at the throat of a tin smelting fumigation furnace with localized high-temperature melting. Background Technology
[0002] In the tin smelting fume furnace process, flue gas and slag with complex compositions easily adhere and accumulate at the high-temperature throat, forming slag that rapidly reduces the cross-sectional area of the passage and hinders the smooth discharge of high-temperature flue gas containing tin volatiles. This leads to a sharp increase in furnace back pressure, requiring a significant increase in blast pressure to maintain the necessary reducing atmosphere and blast volume, resulting in a substantial increase in energy consumption. In cases of severe slag formation, even increased pressure cannot guarantee ventilation, causing a sharp drop in tin volatilization efficiency and forcing a reduction in the feed rate (load reduction), directly impacting tin production and metal recovery rate.
[0003] Severe blockage of the slag duct is one of the most common causes of unplanned shutdowns. The slag clumps are abnormally hard or partially melted, making cleaning extremely difficult, and suspended slag clumps risk sudden collapse. The narrow space and extremely high temperature in the slag duct, coupled with the possibility that the flue gas contains toxic volatiles such as arsenic and lead, expose slag cleaning workers to a high-risk environment of high-temperature burns, scalds, inhalation of toxic gases, and exposure to arsenic and lead, resulting in immense labor intensity. These impacts ultimately translate into soaring costs: including the manpower and material consumption from frequent slag cleaning, high equipment maintenance costs, huge losses from unplanned shutdowns, increased blast furnace energy consumption, steam losses due to decreased waste heat recovery efficiency, and, most importantly, profit losses due to a decline in tin metal recovery rates.
[0004] Therefore, providing an online slag melting process to achieve preventive intervention and graded treatment of slag buildup in the throat, avoiding the development of slag buildup to the point where furnace shutdown is necessary, and improving the overall technical and economic indicators and safety production level of tin smelting furnaces are urgent technical problems to be solved in this field. Utility Model Content
[0005] This invention proposes a system for locally high-temperature melting of slag at the throat of a tin smelting furnace. This system has high equipment utilization, low safety and environmental risks, and good technical and economic indicators. It can increase the effective time of the tin smelting furnace by 300%, significantly reduce the safety and environmental risks of cleaning the throat slag, increase the amount of tin in the tin fumes by 15%, increase the direct tin recovery rate by 3.5%, and increase the metal balance by 1.1%.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A system for locally high-temperature melting of tin smelting slag at the throat of a fuming furnace, wherein an oxygen-enriched natural gas burner is installed above the air-coal mixed burner of the fuming furnace, and the oxygen-enriched natural gas burner is parallel to the furnace wall of the fuming furnace.
[0008] The side wall of the fuming furnace is provided with a liquid slag inlet and a cold material inlet, and the oxygen-enriched natural gas burner is located below the liquid slag inlet and the cold material inlet; the top of the fuming furnace is provided with a dust collection system.
[0009] Preferably, the inner side of the oxygen-enriched natural gas burner is an oxygen-enriched natural gas channel, and the outer side is a circulating water cooling jacket.
[0010] Preferably, the oxygen-enriched natural gas burner is connected to both a natural gas station and an oxygen station.
[0011] Preferably, a first mixing tank is provided between the oxygen station and the oxygen-enriched natural gas burner, and the first mixing tank is also connected to a first blower;
[0012] Preferably, the air-coal mixing burner is connected to the pulverized coal tank and the oxygen station.
[0013] Preferably, a second mixing air tank is provided between the oxygen station and the coal-air mixing burner, and the second mixing air tank is also connected to a second blower.
[0014] Preferably, the bottom of the fumigation furnace is provided with a slag throwing port.
[0015] This utility model equipment can use oxygen-enriched natural gas to inject oxygen-enriched natural gas into the slag in stages for high-temperature slag burning. The oxygen-enriched natural gas and carbon monoxide in the furnace burn intensely and release heat on the surface of the slag in the throat. The local temperature on the surface of the slag in the throat can reach 1300-1350℃. Most of the slag in the throat melts and falls into the slag pool, increasing the effective time of the fuming furnace by 300%.
[0016] By adjusting the tin content of the materials fed into the furnace, the amount of tin in the flue dust during oxygen-enriched slag burning is similar to that during normal production, which significantly reduces the safety and environmental risks of cleaning the throat slag. The amount of tin in the flue dust of the fuming furnace is increased by 15%, the direct tin recovery rate is increased by 3.5%, and the metal balance is increased by 1.1%.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] (1) High equipment utilization: This utility model uses a three-stage step-by-step intervention to utilize oxygen-rich natural gas to form a local high temperature of 1300-1350°C on the surface of the slag and carbon monoxide, which melts most of the slag in the throat and avoids forced shutdown caused by rapid slag thickening. This utility model increases the effective operating time of the fuming furnace under the threat of slag in the throat by 300%, greatly reduces the number and duration of unplanned shutdowns, and significantly improves the production efficiency and capacity utilization of the equipment.
[0019] (2) Low safety and environmental risks: Traditional methods require manual cleaning when the throat is severely sludge-laden (often reaching 40-45% or more). Workers must perform high-intensity, high-risk operations in a narrow, high-temperature, and toxic environment (containing volatile substances such as arsenic and lead). This utility model extends the effective operating time of the fuming furnace and reduces the number of throat cleanings through melting intervention. This greatly reduces the frequency and duration of high-risk manual sludge cleaning, effectively avoiding serious safety and occupational health risks such as high-temperature burns, scalds, inhalation of toxic gases, and exposure to arsenic and lead. At the same time, it reduces the secondary pollution that may be caused by the sludge cleaning process. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings in this description are merely embodiments of this utility model.
[0021] Figure 1 This is a system structure diagram of an embodiment of the present utility model. Detailed Implementation
[0022] The embodiments of the present invention are described below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.
[0023] like Figure 1 This utility model provides a system for slagging at the throat of a tin smelting furnace at local high temperature: an oxygen-enriched natural gas burner 2 is set above the air-coal mixing burner 4 of the tin smelting furnace 1, and the oxygen-enriched natural gas burner is parallel to the furnace wall of the tin smelting furnace 1.
[0024] The side wall of the fuming furnace 1 is provided with a liquid slag inlet 12 and a cold material inlet 3, and the oxygen-enriched natural gas burner 2 is located below the liquid slag inlet 12 and the cold material inlet 3; the tin content and silica content of the material are poured into the liquid slag inlet 12 and the cold material inlet 3 to enter the mixed material for coordinated control.
[0025] The top of the fuming furnace 1 is equipped with a dust collection system 13. By controlling the negative pressure at the inlet of the dust collection system 13, the negative pressure inside the furnace is balanced, and there is no smoke overflow.
[0026] The inner side of the oxygen-enriched natural gas burner 2 is an oxygen-enriched natural gas channel, and the outer side is a circulating water cooling jacket. The oxygen-enriched natural gas burner 2 is connected to the natural gas station 14 and the oxygen station 9 respectively. A first mixing air tank 11 is provided between the oxygen station 9 and the oxygen-enriched natural gas burner 2. The first mixing air tank 11 is also connected to the first blower 10. The oxygen-enriched natural gas in the oxygen-enriched natural gas burner 2 is provided by the first blower 10 and the oxygen station 9. After being mixed by the first mixing air tank 11, it is mixed with the natural gas from the natural gas station 14 and sprayed onto the sludge surface in the throat. The local temperature can reach 1300-1350℃.
[0027] The air-coal mixing burner 4 is connected to the pulverized coal tank 6 and the oxygen station 9. A second mixing air tank 8 is provided between the oxygen station 9 and the air-coal mixing burner 4. The second mixing air tank 8 is also connected to the second blower 7. Nitrogen is sent from the pulverized coal tank 6 to the air-coal mixing burner 4. The second blower 7 supplies air, which is mixed with the oxygen supplied by the oxygen station 9 in the second mixing air tank 8. The oxygen-enriched natural gas supplied by the second mixing air tank 8 can simultaneously blow pulverized coal into the furnace. The furnace reduction coefficient is controlled by the oxygen content of the oxygen-enriched natural gas in the mixing air tank and the proportion of pulverized coal injected into the pulverized coal tank.
[0028] Furthermore, the bottom of the fuming furnace is equipped with a slag discharge port 5. During the slag discharge process, the slag discharge port 5 can be opened to determine the plugging time based on the amount of liquid slag provided by the top-blown furnace, ensuring a balanced amount of high-temperature liquid slag, making full use of the heat of the liquid slag, and shortening the smelting time of a single furnace.
[0029] Material processing: Taking an 8m² fuming furnace with dimensions of 2.83×2.83 in a tin smelter as the research object, the material contained 4.2-5.1% tin, had a silica content of 0.90-0.98, a slag burning temperature of 1300-1350℃, a conventional smelting reduction coefficient of 0.92-0.98, a conventional feeding rate of 25-35t / h, and a conventional single-furnace smelting time of 2.67h during conventional smelting.
[0030] Application Example 1
[0031] Adopting such Figure 1 The related apparatus system provides a method for slag formation at the throat of a localized high-temperature molten tin smelting furnace, specifically including the following steps:
[0032] (1) The material with 4.5% tin content and 0.95 silica content was fed into the furnace for smelting. The single furnace capacity was 35t, the smelting time was 2.7h, and the feed rate was 35t / h. After 12 days, the slag thickness in the throat 4.5m above the air-coal mixed burner reached 0.5m (in the direction of the liquid slag inlet). The oxygen-enriched natural gas burner in the direction of the liquid slag inlet was pushed into the furnace, and oxygen-enriched natural gas was injected into the throat slag. The oxygen concentration was 34%, and the natural gas content was 15%. The single furnace capacity was reduced to 30t, the tin content of the material was adjusted to 7.5%, and the feed rate was adjusted accordingly. The furnace speed was adjusted to 24.5 t / h, the silica content to 0.88, the furnace reduction coefficient to 0.86, and the single-furnace smelting time to 3.4 h. The surface temperature of the throat slag was 1345℃. In the first 10 hours of slag burning, the throat slag partially melted and fell into the molten pool. After 10-12 hours, the thickness of the throat slag no longer changed significantly. The supply of oxygen-enriched natural gas was stopped, the oxygen-enriched natural gas burner was removed, and the furnace was smelted again with 4.5% tin content and 0.95 silica content material. The single-furnace processing capacity was 35 t, and the smelting time was 2.7 h.
[0033] (2) After 20 days of operation, the slag thickness in the throat 3-4.2m above the coal-air mixture burner reached 0.79m (semi-circular). The oxygen-enriched natural gas burner above the slag was pushed into the furnace, and oxygen-enriched natural gas was injected into the throat slag. The oxygen concentration was 37%, the natural gas content was 16%, the tin content of the material was adjusted to 6.7%, the single furnace capacity was adjusted to 31.5t, the feed rate was adjusted to 26.3t / h, the silica content was adjusted to 0.87, the furnace reduction coefficient was adjusted to 0.89, the single furnace smelting time was adjusted to 3.3h, and the throat slag surface temperature was 1340℃. In the first 19 hours of slag burning, the throat slag partially melted and fell into the molten pool. From 19 to 21 hours, the throat slag thickness no longer changed significantly. The supply of oxygen-enriched natural gas was stopped, the oxygen-enriched natural gas burner was removed, and the material with 4.5% tin content and 0.95 silica content was reinstated for smelting in the furnace. The single furnace capacity was 35t, and the smelting time was 2.7h.
[0034] (3) After 35 days of furnace operation, the slag thickness in the throat section (3-5.5m above the coal-air mixture burner) reaches 1m (ring-shaped). Four oxygen-enriched natural gas burners are then pushed into the furnace, and oxygen-enriched natural gas is continuously injected into the throat slag. The oxygen concentration is 31%, the natural gas content is 14%, the tin content of the material is adjusted to 5.7% compared to conventional smelting, the single-furnace capacity is adjusted to 33.6t, the feed rate is adjusted to 31.5t / h, the silica content is adjusted to 0.87, and the furnace reduction coefficient is adjusted to 0. The single-furnace smelting time was adjusted to 2.84 hours, the surface temperature of the slag in the throat was 1330℃, and the slag continued to melt during the 35-48 day period. After 48 days, when the thickness of the slag in the throat 4.8m above the air-coal mixed burner reached 1.2m, the flue gas passage narrowed, and there was a risk of molten slag blocking the flue. All oxygen-enriched natural gas burners were removed, and the supply of oxygen-enriched natural gas was stopped. The furnace was then smelted with 4.8% tin content and 0.90 silica content material. The single-furnace processing capacity was 34t, and the smelting time was 2.8 hours.
[0035] (4) When the thickness of the pharyngeal crust reaches 1.28m on the 56th day after the furnace is started, the furnace is stopped and the pharyngeal crust is cleaned.
[0036] The entire process involves adaptively adjusting the negative pressure inside the furnace to ensure that no flue gas overflows.
[0037] This method can achieve a single furnace cycle of up to 56 days, with a tin metal direct recovery rate of >95.7%, a tin metal balance of >99.8%, and a tin dust emission of 545 tons / month.
[0038] Application Example 2
[0039] Adopting such Figure 1 The related apparatus system provides a method for slag formation at the throat of a localized high-temperature molten tin smelting furnace, specifically including the following steps:
[0040] (1) The material with 4.2% tin content and 0.96 silica content was fed into the furnace for smelting. The single furnace capacity was 36t, the smelting time was 2.8h, and the feed rate was 36t / h. After 11 days, the slag thickness in the throat 4.2m above the air-coal mixed burner reached 0.45m (in the direction of the liquid slag inlet). The oxygen-enriched natural gas burner in the direction of the liquid slag inlet was pushed into the furnace, and oxygen-enriched natural gas was injected into the throat slag. The oxygen concentration was 35% and the natural gas content was 15%. The single furnace capacity was reduced to 29.5t, and the tin content of the material was adjusted to 7.7%. The feed rate was adjusted to 25.2 t / h, the silica content to 0.89, the furnace reduction coefficient to 0.91, and the single-furnace smelting time to 3.6 h. The surface temperature of the throat slag was 1348 ℃. In the first 8 hours of slag burning, the throat slag partially melted and fell into the molten pool. After 8-10 hours, the thickness of the throat slag no longer changed significantly. The supply of oxygen-enriched natural gas was stopped, the oxygen-enriched natural gas burner was removed, and the 4.2% tin-containing material with a silica content of 0.96 was fed into the furnace for smelting. The single-furnace processing capacity was 36 t, and the smelting time was 2.8 h.
[0041] (2) After 21 days of furnace operation, the slag thickness in the throat 3.3-4.6m above the coal-air mixture burner reached 0.82m (excluding the cold feed inlet on the three sides). The oxygen-enriched natural gas burner above the slag was pushed into the furnace, and oxygen-enriched natural gas was injected into the throat slag. The oxygen concentration was 38%, the natural gas content in the mixed gas was 17%, the tin content of the material was adjusted to 6.9%, the single furnace capacity was adjusted to 31.7t, the feed rate was adjusted to 27t / h, the silica content was adjusted to 0.88, the furnace reduction coefficient was adjusted to 0.90, and the single furnace smelting time was adjusted to 3.4h. In the first 17 hours of slag burning, the throat slag partially melted and fell into the molten pool. From 17 to 19 hours, the thickness of the throat slag no longer changed significantly. The supply of oxygen-enriched natural gas was stopped, the oxygen-enriched natural gas burner was removed, and the material with 4.2% tin content and 0.96 silica content was reinstated for smelting in the furnace. The single furnace capacity was 36t, and the smelting time was 2.8h.
[0042] (3) After 37 days of furnace operation, the slag thickness in the throat section 2.9-5.7m above the coal-air mixture burner reaches 0.98m (ring). The four oxygen-enriched natural gas burners are pushed into the furnace, and oxygen-enriched natural gas is continuously injected into the throat slag. The oxygen concentration is 32%, the natural gas content in the mixed gas is 13%, the tin content of the material is adjusted to 5.6%, the single furnace capacity is adjusted to 33.5t, the feed rate is adjusted to 32.4t / h, the silica content is adjusted to 0.88, the furnace reduction coefficient is adjusted to 0.89, and the single furnace smelting time is adjusted to 2.9h. The slag is continuously melted from 37 to 51 days. After 48 days, when the slag thickness in the throat 4.8m above the coal-air mixture burner reaches 1.2m, the flue gas channel narrows and there is a risk of slag clogging the flue. All oxygen-enriched natural gas burners are removed, and the material with 4.7% tin content and 0.85 silica content is fed into the furnace for smelting. The single furnace capacity is adjusted to 35t and the smelting time is adjusted to 2.7h.
[0043] (4) On the 58th day after the furnace is started, when the thickness of the pharyngeal crust reaches 1.29m, the furnace is stopped and the pharyngeal crust is cleaned.
[0044] The entire process involves adaptively adjusting the negative pressure inside the furnace to ensure that no flue gas overflows.
[0045] This method can achieve a single furnace cycle of up to 58 days, with a tin metal direct recovery rate of >95.8%, a tin metal balance of >99.7%, and a tin dust emission of 561 tons / month.
[0046] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A system for slag formation at the throat of a localized high-temperature molten tin smelting furnace, characterized in that, An oxygen-enriched natural gas burner is installed above the air-coal mixing burner of the fuming furnace, and the oxygen-enriched natural gas burner is parallel to the furnace wall of the fuming furnace. The side wall of the fuming furnace is provided with a liquid slag inlet and a cold material inlet, and the oxygen-enriched natural gas burner is located below the liquid slag inlet and the cold material inlet; the top of the fuming furnace is provided with a dust collection system.
2. The system for slag formation at the throat of a localized high-temperature molten tin smelting furnace according to claim 1, characterized in that, The oxygen-enriched natural gas burner has an oxygen-enriched natural gas channel on the inside and a circulating water cooling jacket on the outside.
3. The system for slag formation at the throat of a localized high-temperature molten tin smelting furnace according to claim 1, characterized in that, The oxygen-enriched natural gas burner is connected to both the natural gas station and the oxygen station.
4. The system for slag formation at the throat of a localized high-temperature molten tin smelting furnace according to claim 3, characterized in that, A first mixing tank is provided between the oxygen station and the oxygen-enriched natural gas burner, and the first mixing tank is also connected to a first blower.
5. The system for slag formation at the throat of a localized high-temperature molten tin smelting furnace according to claim 1, characterized in that, The air-coal mixing burner is connected to the pulverized coal tank and the oxygen station.
6. The system for slag formation at the throat of a localized high-temperature molten tin smelting furnace according to claim 5, characterized in that, A second mixing air tank is provided between the oxygen station and the coal-air mixing burner, and the second mixing air tank is also connected to a second blower.
7. The system for slag formation at the throat of a localized high-temperature molten tin smelting furnace according to claim 1, characterized in that, The bottom of the fuming furnace is equipped with a slag throwing port.