Flash and top blowing coupled molten pool tin smelting device and method

Abstract

The invention discloses a flash and top blowing coupled molten pool tin smelting device and method, and belongs to the technical field of pyrogenic smelting of crude tin. Tin concentrate, fuming enriched tin middling and powdery tin smoke dust are subjected to ore blending with a flux and then are smelted; adding a carbonaceous reducing agent into the molten pool, and reducing to form a CO reducing atmosphere layer at the upper part of the slag layer; and blowing fluidized bed furnace roasting dry powder to the upper part of the CO reducing atmosphere layer, carrying out flash reduction smelting on the fluidized bed furnace roasting dry powder, enabling the fluidized bed furnace roasting dry powder which is not subjected to flash reduction smelting to enter a molten pool, and continuing to carry out a reduction stage in top-blowing molten pool smelting, so that flash and top-blowing coupling is realized, and crude tin is prepared. According to the invention, flash melting pool smelting and top-blowing melting pool smelting are effectively coupled together, fuel consumption can be reduced by about 20%, and the bed capacity is obviously improved.

Description

Technical Field

[0001] The invention relates to the technical field of pyrometallurgical smelting of crude tin, and in particular to a device and method for smelting tin in a molten pool coupled with flash and top blowing. Background Art

[0002] As the world's largest tin producer, China's tin production capacity is highly concentrated in the region. More than 60% of the tin production capacity comes from a few major production enterprises, most of which use oxygen-enriched enhanced molten pool smelting technology, especially TSL technology, as the most advanced crude tin smelting technology today.

[0003] The materials processed in the oxygen-enriched molten pool smelting technology are relatively complex, including tin concentrate, tin middlings after fuming enrichment, dry powder roasted in a fluidized bed furnace, powdered tin smoke produced from tin furnace slag, powdered tin smoke collected in the waste heat boiler and electrostatic precipitator of the flue gas treatment system during top-blown furnace smelting, and other tin-containing powdered materials from different sources in tin smelters.

[0004] Some of these tin-containing powder materials have smaller particle sizes, accounting for about 50% of the materials processed in the oxygen-enriched enhanced molten pool smelting technology. If they are directly added to the molten pool from the top of the molten pool through belt conveyor, the descending distance inside the molten pool is more than 10 meters. These tin-containing materials with smaller particle sizes are easily collected by the dust collector at the same time as the flue gas under the action of the flue gas, so these tin-containing materials with smaller particle sizes need to be granulated with water before they can be added to the molten pool. During the oxygen-enriched enhanced molten pool smelting process, these water-added granulated materials make the moisture content of the entire tin-containing powder material mixture entering the furnace reach 8%-12%. The high moisture content in the tin-containing powder material mixture entering the furnace needs to be evaporated through oxygen-enriched enhanced molten pool smelting, which reduces the furnace bed capacity and increases a lot of energy consumption. In addition, the flue gas collected during the top-blown furnace smelting process will contain a large amount of water vapor, which increases the flue gas treatment volume and treatment cost. For these tin-containing materials with smaller particle sizes, improvements have also been attempted on the basis of keeping the oxygen-enriched enhanced molten pool smelting technology unchanged.

[0005] For example, the patent application number is 2021108065485, a system and method for smelting tin-containing materials. The invention classifies various types of tin-containing materials to obtain low-sulfur and arsenic-containing tin ores and high-sulfur and arsenic-containing tin ores. After pretreatment of the high-sulfur and arsenic-containing tin ores, tin-containing dry materials are obtained. After screening the tin-containing dry materials, fine-grained dry materials and coarse-grained dry materials are obtained; after the low-sulfur and arsenic-containing tin ores and the coarse-grained dry materials are mixed, they are added to the top-blown furnace, and then the fine-grained dry materials and the recovered tin-containing materials are blown into the top-blown spray gun. After smelting, they enter the reduction stage to finally obtain the crude tin product.

[0006] The patent application number is 202110806443X, a side-entry powder top-blown furnace and its processing method. The invention roasts powdered tin smoke, powdered coal and powdered tin in the tin smelting stage, and sprays them into the cylindrical furnace body through a spray gun inserted on the side of the cylindrical furnace body, first smelting and then performing a reduction stage, and finally obtaining a crude tin product.

[0007] Regardless of "a system and method for smelting tin-containing materials" or "a side-entry powder top-blown furnace and its processing method", when the top-blown molten pool smelting remains unchanged, during the smelting stage of the top-blown molten pool smelting, by changing the injection method of tin-containing materials with smaller particle sizes, such as blowing through a top-blowing spray gun or blowing through a side-inserted spray gun, it is not possible to actually save fuel consumption, especially during the side blowing process, the top-blown furnace needs to be improved, which increases the smelting cost.

[0008] Flash smelting is one of the most advanced production processes for smelting heavy non-ferrous metals such as copper and nickel. The basic process principle of flash smelting is: ore with a specified particle size and moisture content is sprayed into the reaction chamber of the flash furnace through a nozzle, so that the ore particles are suspended in the high-temperature oxidizing gas flow, and the oxidation reaction of sulfide minerals occurs rapidly, releasing a large amount of heat energy. During the flash smelting process of copper smelting, the slag formation reaction and matte smelting will be completed simultaneously and quickly. Generally, the fuel consumption of flash smelting is only about 50% of that of traditional smelting processes, so the flash smelting process has the advantages of low energy consumption, large bed capacity, high degree of automation, and clean production environment.

[0009] Patent application No. 2021113126169 discloses a copper flash smelting process, which realizes copper flash smelting under the conditions of average powder particle size less than 200 mesh, water content less than 0.3%, smelting temperature of 1200-1400°C, and oxygen enrichment concentration of 60-100%. Patent application No. 2019112384132 discloses a new type of furnace for mixed smelting of antimony ore volatilization smelting and flash smelting in the same furnace and its smelting method, which realizes antimony flash smelting under the conditions of particle diameter of antimony powder ore less than 10 mm, water content less than 15%, jet velocity of 0.1 m / s-100 m / s, and jet flow rate of 1 g / s-10000 g / s.

[0010] Whether it is copper flash smelting or antimony flash smelting, the fine, low-water copper-containing material or antimony-containing material is quickly oxidized in a high-temperature oxidizing gas flow. There is no method or application of flash smelting in the crude tin smelting process in the prior art.

[0011] Therefore, how to achieve efficient utilization of tin-containing materials with smaller particle size and effectively couple flash smelting with top-blown molten pool smelting to achieve the technical effects of reducing energy consumption and increasing bed capacity is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0012] The present invention aims to solve one of the above-mentioned technical problems in the prior art at least to a certain extent.

[0013] To this end, an object of the present invention is to propose a method and device for molten pool tin smelting coupled with flash and top blowing. In the present invention, after a period of reduction smelting of tin in the top-blown molten pool, a high-temperature CO reducing atmosphere layer will be formed on the upper part of the slag layer, and then the fluidized bed furnace roasted dry powder will be sprayed into the high-temperature CO reducing atmosphere layer at this time. The fluidized bed furnace roasted tin-containing dry powder will react quickly with the high-temperature CO reducing gas to perform flash smelting to generate crude tin. The fluidized bed furnace roasted tin-containing dry powder that has not undergone a complete flash reduction reaction will continue to enter the molten pool, continue the top-blown molten pool smelting reduction process, and regenerate crude tin. The present invention can effectively couple flash and top-blown molten pool smelting to achieve the technical effects of reducing energy consumption and increasing bed capacity.

[0014] To achieve the above object, the present invention adopts the following technical solution:

[0015] A device for smelting tin in a molten pool coupled with flash and top blowing, comprising a top blowing molten pool and a top blowing lance;

[0016] Wherein, the lower half of the top-blowing lance extends into the top-blowing molten pool;

[0017] The top of the top-blown molten pool is provided with a feed inlet and an exhaust gas collection port; one side of the bottom of the top-blown molten pool is provided with a liquid discharge port;

[0018] The upper end of the top-blowing spray gun is provided with a boiling furnace roasting dry powder spray gun inlet, a spray gun third inlet, a spray gun second inlet and a spray gun first inlet from top to bottom; the bottom of the top-blowing spray gun is provided with a top-blowing spray gun outlet, and a boiling furnace roasting dry powder spray outlet is provided above the top-blowing spray gun outlet.

[0019] Furthermore, the top-blown molten pool contains a metal melt layer, a slag layer and a CO reducing atmosphere layer in sequence from bottom to top.

[0020] Furthermore, the top-blowing lance extends into the CO reducing atmosphere layer, and the fluidized bed furnace roasting dry powder spray outlets are all in the CO reducing atmosphere layer; and the height difference between the fluidized bed furnace roasting dry powder spray outlet and the slag layer is 0-500mm.

[0021] The first inlet of the lance is located outside the top-blowing molten pool.

[0022] Furthermore, the fluidized bed furnace roasting dry powder spray port is a conical spray port, and a plurality of evenly arranged spray circular holes are provided on the spraying section of the fluidized bed furnace roasting dry powder spray port;

[0023] The top-blowing lance outlet (13) is provided with a plurality of evenly arranged circular blowing holes on the spraying section.

[0024] The present invention also provides the above-mentioned method for smelting tin in a molten pool by coupling flash and top blowing, comprising the following steps:

[0025] (1) After tin concentrate, tin ore enriched by fuming and powdered tin dust are mixed with flux, oxygen-enriched air is introduced through the first inlet of the spray gun, and dry powder dust is introduced through the second inlet of the spray gun to perform smelting in a top-blown molten pool;

[0026] (2) After smelting, a carbonaceous reducing agent is added to the molten pool, and pulverized coal is introduced through the third inlet of the lance to carry out top-blown molten pool smelting reduction. After 0.3-0.7h of reduction, a CO reducing atmosphere layer is formed on the upper part of the slag layer;

[0027] (3) The fluidized bed roasted dry powder is sprayed onto the upper part of the CO reducing atmosphere layer to carry out flash reduction smelting of the fluidized bed roasted dry powder. The fluidized bed roasted dry powder that has not been smelted through flash reduction is put into the molten pool to continue top-blowing molten pool smelting reduction, and flash and top-blowing coupling is achieved for 0.5-1h to prepare crude tin.

[0028] Furthermore, based on 100% by mass, the tin concentrate, the fumed tin ore, the powdered tin fume and the flux are composed of the following percentages: 45-60% of tin concentrate, 5-15% of fumed tin ore, 20-30% of powdered tin fume and 5-10% of flux;

[0029] The flux is quartz sand and / or limestone.

[0030] Furthermore, the smelting temperature is 1150-1250° C., and the smelting time is 1-1.5 hours.

[0031] Further, the carbonaceous reducing agent is lump coal;

[0032] The carbonaceous reducing agent is added in an amount of 4-6.5 t / h.

[0033] Furthermore, the pulverized coal is introduced into the third inlet of the top-blowing lance, and its back pressure is 0-105kPa and the flow rate is 500-600Nm 3 / h;

[0034] The second inlet of the top-blowing spray gun is fed with dry powder smoke, with a back pressure of 0-100KPa and a flow rate of 1200-1800Nm 3 / h;

[0035] The first inlet of the top-blowing spray gun is fed with oxygen-enriched air, with a back pressure of 0-225KPa and a flow rate of 20000-25000Nm 3 / h;

[0036] The top-blowing spray gun has a fluidized bed furnace for roasting dry powder. The spray gun inlet is fed into the fluidized bed furnace for roasting dry powder. The back pressure is 0-80KPa and the flow rate is 1500-2000Nm 3 / h.

[0037] Furthermore, the particle size of the dry powder roasted in the fluidized bed furnace in step (3) is 0.18-0.85 mm, and the moisture content is 0-0.5%;

[0038] The amount of dry powder sprayed in the fluidized bed furnace is 10-50% of the mass of the tin concentrate.

[0039] In the present invention, the method of spraying the boiling furnace to roast dry powder on the upper part of the CO reducing atmosphere layer only requires shortening the outermost layer of the top blowing lance in the top blowing molten pool smelting and passing the boiling furnace to roast dry powder.

[0040] The beneficial effects of the present invention are:

[0041] (1) The present invention effectively couples flash smelting with top-blown molten pool smelting, overcoming the technical bias in the prior art that flash smelting can only achieve rapid reaction in a high-temperature oxidizing gas flow. The present invention achieves rapid reduction reaction between high-temperature CO reducing gas and tin-containing materials in a high-temperature CO reducing atmosphere layer, thereby realizing flash smelting in the crude tin smelting process.

[0042] (2) The present invention effectively couples flash smelting with top-blown molten pool smelting, which can reduce fuel consumption by about 20%, that is, reduce energy consumption by about 20%, and significantly improve bed capacity.

[0043] (3) The present invention effectively couples flash smelting with top-blowing molten pool smelting, and has the advantages of high degree of automation and clean production environment.

[0044] (4) The flash smelting process of the present invention sprays the boiling furnace to the upper part of the CO reducing atmosphere layer to roast the dry powder, which can be achieved by simply shortening the outermost layer of the top-blowing lance in the top-blowing molten pool smelting and passing the boiling furnace to the outermost layer of the top-blowing lance to roast the dry powder. There is no need to increase additional improvement costs, which will cause a significant increase in production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0046] Figure 1 This is a diagram of one of the application equipments of the flash and top blowing coupled molten pool tin smelting of the present invention;

[0047] Figure 2 It is a schematic diagram of a spray gun used in one application of the flash and top blowing coupled molten pool tin smelting of the present invention.

[0048] Figure 3 This is a flow chart of tin smelting in a molten pool coupled with flash and top blowing according to the present invention;

[0049] In the accompanying drawings, the structures represented by the reference numerals are listed as follows: 1-top blowing molten pool, 2-top blowing lance;

[0050] 11-feeding port, 12-exhaust gas collecting port, 13-liquid discharge port, 14-metal melt layer, 15-slag layer, 16-CO reducing atmosphere layer, 21-boiling furnace roasting dry powder spray gun inlet, 22-spray gun third inlet, 23-spray gun second inlet, 24-spray gun first inlet, 25-top blowing spray gun outlet, 26-boiling furnace roasting dry powder spray outlet. DETAILED DESCRIPTION

[0051] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0052] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0053] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0056] Example 1

[0057] A device for smelting tin in a molten pool coupled with flash and top blowing, comprising a top blowing molten pool 1 and a top blowing lance 2;

[0058] Wherein, the lower half of the top-blowing lance 2 extends into the top-blowing molten pool 1;

[0059] A feed inlet 11 and an exhaust gas collecting port 12 are provided at the top of the top-blown molten pool 1; a liquid discharge port 13 is provided at one side of the bottom of the top-blown molten pool 1;

[0060] The upper end of the top-blowing spray gun 2 is provided with a boiling furnace roasting dry powder spray gun inlet 21, a spray gun third inlet 22, a spray gun second inlet 23 and a spray gun first inlet 24 in sequence from top to bottom; the bottom of the top-blowing spray gun 2 is provided with a top-blowing spray gun outlet 25, and above the top-blowing spray gun outlet 25 is provided with a boiling furnace roasting dry powder spray outlet 26.

[0061] In some embodiments, the top-blown molten pool 1 contains a molten metal layer 14 , a slag layer 15 and a CO reducing atmosphere layer 16 in order from bottom to top.

[0062] In other embodiments, the top-blowing lance 2 extends into the CO reducing atmosphere layer 16, and the fluidized bed furnace roasting dry powder spray outlet 26 is in the CO reducing atmosphere layer 16; and the height difference between the fluidized bed furnace roasting dry powder spray outlet 26 and the slag layer 15 is 0-500mm.

[0063] The first inlet 24 of the lance is located outside the top-blowing molten pool.

[0064] In some embodiments, the fluidized bed furnace roasting dry powder spray port 26 is a conical spray port, and a plurality of evenly arranged spray circular holes are provided on the spraying section of the fluidized bed furnace roasting dry powder spray port 26;

[0065] A plurality of evenly arranged circular blowing holes are provided on the spraying section of the top-blowing lance outlet 25 .

[0066] Example 2

[0067] A method for tin smelting in a molten pool by coupling flash and top blowing:

[0068] (1) Tin concentrate (including the following mass percentage components: Sn: 55.1%, Fe: 3.5%, Ca: 0.6%, Si: 3.2%, and the rest is O), fuming enriched tin ore (including the following mass percentage components: Sn: 40.5%, Fe: 8.7%, Ca: 1.1%, Si: 2.5%, and the rest is O) and powdered tin dust (including the following mass percentage components: Sn: 50.5%, Fe: 0.5%, Ca: 0.8%, Si: 1.6%, and the rest O), mixed in a mass percentage of 45%: 15%: 30%, and then mixed with quartz sand and limestone flux in a 10% ratio, placed in the molten pool from the feed inlet 5 at the top of the molten pool, oxygen-enriched air (oxygen content of 32%) is introduced through the first inlet 12 of the top-blowing lance 1, and dry powder dust is introduced through the second inlet of the lance, and smelted at a temperature of 1250°C for 1.5 hours;

[0069] (2) After the top-blown molten pool smelting is completed, carbon blocks are added through the feed port 5, and pulverized coal is introduced into the third inlet 10 of the top-blown lance 1 to carry out top-blown molten pool smelting reduction for 0.5 h, forming a CO reducing atmosphere layer on the upper part of the slag layer;

[0070] (3) Fluidized bed roasted dry powder (comprising the following components in percentage by weight: Sn: 38.5%, Fe: 15.7%, Ca: 1.4%, Si: 4.1%, and the remainder being O) is introduced into the fluidized bed roasted dry powder spray gun inlet 2 of the top-blowing spray gun 1. The fluidized bed roasted dry powder is subjected to flash reduction smelting in a CO reducing atmosphere layer. The fluidized bed roasted dry powder that has not been flash reduced is introduced into the molten pool for further reduction in top-blowing molten pool smelting, thereby achieving flash and top blowing coupling for 1 hour to prepare crude tin.

[0071] Strengthening reduction smelting can increase processing capacity by 10-20% in the same period of time, saving 20% ​​energy year-on-year.

[0072] Example 3

[0073] A method for tin smelting in a molten pool by coupling flash and top blowing:

[0074] (1) Tin concentrate (including the following mass percentage components: Sn: 45.5%, Fe: 13.8%, Ca: 1.6%, Si: 5.5%, the rest is O), fuming enriched tin ore (including the following mass percentage components: Sn: 50.2%, Fe: 8.5%, Ca: 1.3%, Si: 1.5%, the rest is O) and powdered tin dust (including the following mass percentage components: Sn: 52.5%, Fe : 3.6%, Ca: 1.0%, Si: 1.2%, and the rest O), mixed in a mass percentage of 60%: 5%: 30%, and then mixed with quartz sand and limestone flux in a 10% ratio, placed in the molten pool from the feed inlet 5 at the top of the molten pool, oxygen-enriched air (oxygen content of 35%) is introduced through the first inlet 12 of the top-blowing lance 1, and dry powder dust is introduced through the second inlet of the lance, and smelted at a temperature of 1250° C. for 1.5 hours;

[0075] (2) After the top-blown molten pool smelting is completed, carbon blocks are added through the feed port 5, and pulverized coal is introduced into the third inlet 10 of the top-blown lance 1 to carry out top-blown molten pool smelting reduction for 0.5 h, forming a CO reducing atmosphere layer on the upper part of the slag layer;

[0076] (3) Fluidized bed roasted dry powder (comprising the following components in percentage by weight: Sn: 40.0%, Fe: 13.0%, Ca: 1.4%, Si: 4.8%, and the remainder being O) is introduced into the fluidized bed roasted dry powder spray gun inlet 2 of the top-blowing spray gun 1. The fluidized bed roasted dry powder is subjected to flash reduction smelting in a CO reducing atmosphere layer. The fluidized bed roasted dry powder that has not been flash reduced smelted enters the molten pool and continues to be reduced in top-blowing molten pool smelting, thereby achieving flash and top blowing coupling for 1 hour to prepare crude tin.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A device for molten pool tin smelting by coupling flash and top blowing, characterized in that: Including top blowing molten pool and top blowing lance; Wherein, the lower half of the top-blowing lance extends into the top-blowing molten pool; The top of the top-blown molten pool is provided with a feed inlet and an exhaust gas collection port; one side of the bottom of the top-blown molten pool is provided with a liquid discharge port; The upper end of the top-blowing spray gun is provided with a boiling furnace roasting dry powder spray gun inlet, a spray gun third inlet, a spray gun second inlet and a spray gun first inlet from top to bottom; the bottom of the top-blowing spray gun is provided with a top-blowing spray gun outlet, and a boiling furnace roasting dry powder spray outlet is provided above the top-blowing spray gun outlet.

2. The device for molten pool tin smelting by coupling flash and top blowing according to claim 1, characterized in that: The top-blown molten pool contains a metal melt layer, a slag layer and a CO reducing atmosphere layer in sequence from bottom to top.

3. The device for tin smelting in a molten pool coupled with flash and top blowing according to claim 2, characterized in that: The top-blowing lance extends into the CO reducing atmosphere layer, and the fluidized bed furnace roasting dry powder spray outlets are all in the CO reducing atmosphere layer; The first inlet of the lance is located outside the top-blowing molten pool.

4. The device for molten pool tin smelting by coupling flash and top blowing according to claim 3, characterized in that: The fluidized bed furnace roasting dry powder spray port is a conical spray port, and a plurality of evenly arranged spray circular holes are arranged on the spraying section of the fluidized bed furnace roasting dry powder spray port; The top-blowing lance outlet (13) is provided with a plurality of evenly arranged circular blowing holes on the spraying section.

5. A method for tin smelting in a molten pool by coupling flash and top blowing, characterized in that: The method comprises the following steps: (1) After tin concentrate, tin ore enriched by fuming and powdered tin dust are mixed with flux, oxygen-enriched air is introduced through the first inlet of the spray gun, and dry powder dust is introduced through the second inlet of the spray gun to perform smelting in a top-blown molten pool; (2) After smelting, a carbonaceous reducing agent is added to the molten pool, and pulverized coal is introduced through the third inlet of the lance to carry out top-blown molten pool smelting reduction. After 0.3-0.7h of reduction, a CO reducing atmosphere layer is formed on the upper part of the slag layer; (3) The fluidized bed roasted dry powder is sprayed onto the upper part of the CO reducing atmosphere layer to carry out flash reduction smelting of the fluidized bed roasted dry powder. The fluidized bed roasted dry powder that has not been smelted through flash reduction is put into the molten pool to continue top-blowing molten pool smelting reduction, and flash and top-blowing coupling is achieved for 0.5-1h to prepare crude tin.

6. The method for tin smelting in a molten pool by coupling flash and top blowing according to claim 5, characterized in that: Based on 100% by mass, the tin concentrate, the fumed tin ore, the powdered tin fume and the flux are composed of the following percentages: 45-60% of tin concentrate, 5-15% of the fumed tin ore, 20-30% of the powdered tin fume and 5-10% of the flux; The flux is quartz sand and / or limestone.

7. The method for tin smelting in a molten pool by coupling flash and top blowing according to claim 6, characterized in that: The smelting temperature is 1150-1250° C., and the smelting time is 1-1.5 hours.

8. The method for tin smelting in a molten pool by coupling flash and top blowing according to claim 6, characterized in that: The carbonaceous reducing agent is lump coal; The carbonaceous reducing agent is added in an amount of 4-6.5 t / h.

9. The method for tin smelting in a molten pool by coupling flash and top blowing according to claim 5, characterized in that: The third inlet of the top-blowing lance introduces pulverized coal, with a back pressure of 0-105 kPa and a flow rate of 500-600 Nm 3 / h; The second inlet of the top-blowing spray gun is fed with dry powder smoke, with a back pressure of 0-100KPa and a flow rate of 1200-1800Nm 3 / h; The first inlet of the top-blowing spray gun is fed with oxygen-enriched air, with a back pressure of 0-225KPa and a flow rate of 20000-25000Nm 3 / h; The top-blowing spray gun has a fluidized bed furnace for roasting dry powder. The spray gun inlet is fed into the fluidized bed furnace for roasting dry powder. The back pressure is 0-80KPa and the flow rate is 1500-2000Nm 3 / h.

10. The method for tin smelting in a molten pool by coupling flash and top blowing according to claim 5, characterized in that: The particle size of the dry powder roasted in the fluidized bed furnace in step (3) is 0.18-0.85 mm, and the moisture content is 0-0.5%; The amount of dry powder sprayed in the fluidized bed furnace is 10-50% of the mass of the tin concentrate.

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