Method and system for resource treatment of smelting flue gas

Abstract

The invention discloses a method and a system for resource treatment of smelting flue gas. The method comprises the following steps: inputting mixed gas containing sulfur dioxide and reducing gas into a reduction tower; in the reduction tower, newly input mixed gas enters a first reaction space through a first heat exchange channel and is subjected to a first-stage oxidation-reduction reaction under the action of a catalyst layer; the reacted mixed gas enters the second heat exchange channel and exchanges heat with the mixed gas in the first heat exchange channel; the mixed gas subjected to heat exchange enters a second reaction space and is subjected to a second-stage oxidation-reduction reaction under the action of a catalyst layer; the reacted mixed gas is input into a condenser, and gaseous sulfur in the mixed gas is condensed through the condenser. The in-tower heat exchanger is arranged in the reduction tower, the integrated design is adopted, the occupied area and the flue gas pipeline are saved, the equipment cost is reduced, meanwhile, the shortening of the flue gas pipeline reduces the heat loss, and the energy utilization rate is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of smelting flue gas treatment, and specifically relates to a method and system for resource-based treatment of smelting flue gas. Background Art

[0002] At present, the mainstream method for treating flue gas containing sulfur dioxide in smelters is to first convert the sulfur dioxide in the flue gas into concentrated sulfuric acid, and then perform flue gas desulfurization on the remaining flue gas. As a highly corrosive and toxic liquid, concentrated sulfuric acid faces many problems in transportation and storage. For some remote areas or enterprises with no sulfuric acid users within a few hundred kilometers, the high cost of transportation and storage of concentrated sulfuric acid directly restricts the development of enterprises.

[0003] In recent years, many domestic enterprises have developed technologies for resource-based disposal of smelting flue gas, especially the technology of preparing sulfur dioxide in smelting flue gas into sulfur. For example, invention patent CN105502302A discloses a method and system for preparing smelting flue gas into sulfur. First, the smelting flue gas is purified to obtain high-purity sulfur dioxide gas. The pure sulfur dioxide gas and hydrogen sulfide gas enter three fixed bed reactors in series to react and generate sulfur. An additional fixed bed reactor is required before the three fixed bed reactors in series to react a portion of the prepared sulfur product with water gas, coal and other substances to form hydrogen sulfide gas. The four fixed bed reactors are connected in series, the process pipeline is complex, and corresponding heat exchangers are required, and the equipment occupies a large area. Summary of the invention

[0004] Based on this, in order to address the problem of large equipment footprint in the existing flue gas preparation system for sulfur, it is necessary to provide a method and system for resource disposal of smelting flue gas that can treat sulfur dioxide-containing flue gas and has a small equipment footprint.

[0005] The technical solution proposed in this application is: A method for resource-based disposal of smelting flue gas, comprising the steps of: Inputting a mixed gas containing sulfur dioxide and reducing gas into a reduction tower; In the reduction tower: the newly input mixed gas enters the first reaction space through the first heat exchange channel, and the first stage of redox reaction occurs under the action of the catalyst layer; the mixed gas after the reaction enters the second heat exchange channel and exchanges heat with the mixed gas in the first heat exchange channel; the mixed gas after heat exchange enters the second reaction space, and the second stage of redox reaction occurs under the action of the catalyst layer; The mixed gas after the reaction in the second reaction space is input into a condenser, and the gaseous sulfur in the mixed gas is condensed by the condenser.

[0006] By adopting the above-mentioned method of resource-based disposal of smelting flue gas, the gas containing sulfur dioxide is mixed with the reducing gas and then enters the reduction device for reduction to generate gaseous sulfur, which is then condensed through the condenser. Compared with concentrated sulfuric acid, sulfur is more convenient to transport and store, which effectively reduces the transportation and storage costs and also improves safety. At the same time, the heat exchanger in the tower is built into the reduction tower, and the integrated design saves floor space and flue gas ducts, reduces equipment costs, and shortens the flue gas duct to reduce heat loss and improve energy utilization.

[0007] Further, the second heat exchange channel includes a first sub-channel and a second sub-channel; In the reduction tower: the newly input mixed gas enters the first catalytic layer through the first heat exchange channel, and the first stage of redox reaction occurs under the action of the first catalytic layer. The mixed gas after the reaction enters the first sub-channel and exchanges heat with the mixed gas in the downstream section of the first heat exchange channel. The mixed gas after the heat exchange enters the second catalytic layer, and the first stage of redox reaction continues to occur under the action of the second catalytic layer. The mixed gas after the reaction enters the second sub-channel and exchanges heat with the mixed gas in the upstream section of the first heat exchange channel. The mixed gas after the heat exchange enters the second reaction space, and the second stage of redox reaction occurs under the action of the third catalytic layer.

[0008] Furthermore, the mixed gas after heat exchange in the second sub-channel enters the heat exchanger outside the tower, and then enters the second reaction space.

[0009] Furthermore, the reducing gas is one or more of carbon monoxide, hydrogen, natural gas and hydrogen sulfide; and the temperature of the redox reaction is 400-700°C.

[0010] Furthermore, the method further comprises the steps of: S110, purifying smelting flue gas; S120, deoxygenating the purified smelting flue gas; S130, mixing the deoxygenated gas with the reducing gas to form a mixed gas containing sulfur dioxide and the reducing gas.

[0011] Furthermore, in the condenser: the condensed liquid sulfur is used to prepare products through a production line, and the non-condensable gas is input into an incinerator for incineration.

[0012] A system for resource-based disposal of smelting flue gas, comprising: A gas delivery component capable of delivering a mixed gas containing sulfur dioxide and reducing gas; A reduction device, comprising a reduction tower and an in-tower heat exchanger, wherein the in-tower heat exchanger is arranged in the reduction tower; The reduction tower has a first reaction space and a second reaction space, and the first reaction space and the second reaction space are both provided with a catalytic layer; the heat exchanger in the tower has a first heat exchange channel and a second heat exchange channel capable of exchanging heat with the first heat exchange channel, and the air supply component is connected to the input end of the first heat exchange channel; The output end of the first heat exchange channel is connected to the inlet of the first reaction space, the outlet of the catalyst layer in the first reaction space is connected to the input end of the second heat exchange channel; the output end of the second heat exchange channel is connected to the inlet of the second reaction space; The system for resource-based disposal of smelting flue gas also includes a condenser, which is connected to the outlet of the second reaction space.

[0013] Further, the second heat exchange channel includes a first sub-channel and a second sub-channel; the catalytic layer includes a first catalytic layer, a second catalytic layer and a third catalytic layer, the first catalytic layer and the second catalytic layer are arranged in the first reaction space at intervals, and the output end of the first heat exchange channel is connected to the inlet of the first catalytic layer, the outlet of the first catalytic layer is connected to the input end of the first sub-channel, the output end of the first sub-channel is connected to the inlet of the second catalytic layer, the outlet of the second catalytic layer is connected to the input end of the second sub-channel, and the output end of the second sub-channel is connected to the second reaction space; the third catalytic layer is arranged in the second reaction space; The gas in the first heat exchange channel is transported along a first direction, and the first sub-channel and the second sub-channel are arranged in sequence along a second direction opposite to the first direction.

[0014] Furthermore, the reduction device further comprises an external heat exchanger, the output end of the second subchannel is communicated with the input end of the external heat exchanger, and the output end of the external heat exchanger is communicated with the inlet of the second reaction space.

[0015] Furthermore, it also includes a purification device, a deoxygenation device and a gas supply device, wherein the purification device is used to purify the gas containing sulfur dioxide and input the purified gas into the deoxygenation device, the deoxygenation device is used to remove oxygen from the gas and input the deoxygenated gas into the gas supply component, and the gas supply device is used to input reducing gas into the gas supply component.

[0016] In summary, the method and system for resource-based disposal of smelting flue gas provided in this application have at least the following advantages: 1. The smelting flue gas is first purified and deoxygenated before subsequent treatment. Sulfur is prepared using high-concentration sulfur dioxide, which reduces the gas volume of the reduction device, reduces equipment specifications, and reduces investment costs. At the same time, no high-temperature dust removal is required in the subsequent process, which prevents dust from entering the sulfur and improves the quality of the sulfur. 2. The catalytic reaction temperature is low and the operating conditions are mild, which can realize continuous production; 3. The heat exchanger in the tower is built into the reduction tower. The integrated design saves floor space and flue gas ducts, reduces equipment costs, and shortens the flue gas duct to reduce heat loss and improve energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. They are used to explain the present application together with the embodiments of the present application and do not constitute a limitation of the present application.

[0018] Figure 1 A schematic diagram of the structure of a system for resource-based disposal of smelting flue gas provided in one embodiment of the present application; Figure 2 for Figure 1 The figure shows a schematic diagram of the structure of the reduction device in the system for resource recovery and disposal of smelting flue gas.

[0019] Description of labels: 110, air delivery assembly; 120, purification device; 130, air supply device; 140, deoxygenation device; 150, exhaust mechanism; 200, reduction device; 210, reduction tower; 211, first reaction space; 212, second reaction space; 213, connecting space; 214, first partition; 215, second partition; 220, heat exchanger in tower; 221, first heat exchange channel; 222, first sub-channel; 223, second sub-channel; 230, preheater; 241, first catalytic layer; 242, second catalytic layer; 243, third catalytic layer; 250, heat exchanger outside tower; 260, connecting pipe; 310, condenser; 320, incinerator; 330, liquid storage tank; 340, granulator; 350, conveying device; 360, packaging machine. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0022] On the one hand, the present application provides a system for resource-based treatment of smelting flue gas, which can treat smelting flue gas in a resource-based manner with low cost.

[0023] like Figure 1 As shown, in one embodiment, the system for resource-based disposal of smelting flue gas includes a gas supply component 110, a reduction device 200 and a condenser 310. The gas supply component 110 can deliver a mixed gas including sulfur dioxide and a reducing gas, wherein the sulfur dioxide comes from the smelting flue gas, and the reducing gas can be one or more of natural gas, carbon monoxide, hydrogen sulfide and hydrogen. At the same time, it can be determined that at least other impurities will exist in the mixed gas, such as impurities other than sulfur dioxide in the smelting flue gas.

[0024] The reduction device 200 is connected to the gas supply assembly 110 to react the reduction gas with sulfur dioxide to generate gaseous sulfur. The condenser 310 is connected to the reduction device 200 to obtain gaseous sulfur and condense the gaseous sulfur. Compared with concentrated sulfuric acid, sulfur is less dangerous, so the transportation cost and storage cost are lower.

[0025] In the above-mentioned system for resource-based disposal of smelting flue gas, the gas containing sulfur dioxide is mixed with the reducing gas and then enters the reduction device 200 for reduction to generate gaseous sulfur, which is then condensed by the condenser 310. Compared with concentrated sulfuric acid, sulfur is more convenient to transport and store, thereby effectively reducing the transportation and storage costs, and also improving safety.

[0026] In one embodiment, the system for resource recovery of smelting flue gas also includes a purification device 120 and a gas supply device 130, both of which are connected to the gas supply component 110, and the purification device 120 can obtain and purify the gas containing sulfur dioxide, and then input the purified gas into the gas supply component 110; the gas supply device 130 is used to input reducing gas into the gas supply component 110, so that the purified gas and the reducing gas are mixed in the gas supply component 110, and then the mixed gas including sulfur dioxide and reducing gas is input into the reduction device 200 through the gas supply component 110.

[0027] In one embodiment, the purification device 120 includes a washing tower, a cooling tower and an electrostatic precipitator. Fluorine removal agent, mercury removal agent and other agents can be added to the washing tower, and corresponding agents can be added according to the impurities in the smelting flue gas to remove non-metallic impurities such as fluorine and arsenic and metal impurities such as copper and mercury in the smelting flue gas; the cooling tower is arranged downstream of the washing tower to cool the washed gas; the electrostatic precipitator is arranged downstream of the cooling tower to remove acid mist in the cooled gas, thereby completing the purification of the smelting flue gas.

[0028] In one embodiment, the system for resource-based disposal of smelting flue gas further includes a deoxygenator 140. The deoxygenator 140 is disposed between the purification device 120 and the gas supply assembly 110, and the deoxygenator 140 is used to remove oxygen from the mixed gas and input the mixed gas after oxygen removal into the gas supply assembly 110. It should be noted that the main component of the deoxygenated gas is sulfur dioxide, and it also contains a small amount of water, nitrogen, oxygen, carbon dioxide, etc., but the concentration of oxygen is less than 1%.

[0029] In one embodiment, the air supply assembly 110 includes a delivery pipeline and a fan, one end of the delivery pipeline is connected to the deoxygenation device 140, and the other end is connected to the reduction device 200; the air supply device 130 is connected to the delivery pipeline, and is used to input the reduction gas into the delivery pipeline, so that the gas containing sulfur dioxide and the reduction gas are mixed in the delivery pipeline. The fan is arranged in the delivery pipeline, and is used to guide the mixed gas to be input into the reduction device 200.

[0030] Please also see Figure 2 Further, the reduction device 200 includes a reduction tower 210 and a heat exchanger 220 in the tower, and the heat exchanger 220 in the tower is arranged in the reduction tower 210. The reduction tower 210 has a first reaction space 211 and a second reaction space 212, and a catalytic layer is arranged in the first reaction space 211 and the second reaction space 212. The heat exchanger 220 in the tower has a first heat exchange channel 221 and a second heat exchange channel capable of exchanging heat with the first heat exchange channel 221, and the gas supply component 110 is connected to the input end of the first heat exchange channel 221 to input the mixed gas into the first heat exchange channel 221.

[0031] The output end of the first heat exchange channel 221 is connected to the inlet of the first reaction space 211, so that the mixed gas is input into the first reaction space 211, and the first stage of the redox reaction occurs under the action of the catalyst layer; the outlet of the catalyst layer in the first reaction space 211 is connected to the input end of the second heat exchange channel, so that the mixed gas that has undergone the redox reaction is input into the second heat exchange channel and heat exchange is performed with the newly input mixed gas in the first heat exchange channel 221. The output end of the second heat exchange channel is connected to the inlet of the second reaction space 212, so that the mixed gas after the heat exchange is input into the second reaction space 212, and the second stage of the redox reaction occurs under the action of the catalyst layer. The outlet of the second reaction space 212 is connected to the condenser 310, so that the mixed gas is input into the condenser 310.

[0032] In the above embodiment, the gas supply component 110 inputs the mixed gas into the first heat exchange channel 221, and the mixed gas enters the first reaction space 211 through the first heat exchange channel 221. Under the action of the catalyst layer, the first stage of the redox reaction occurs, part of the sulfur dioxide is converted into gaseous sulfur, and the temperature of the mixed gas rises. Then the mixed gas enters the second heat exchange channel, and exchanges heat with the gas in the first heat exchange channel 221 in the second heat exchange channel, that is, the mixed gas in the second heat exchange channel is cooled, and the mixed gas in the first heat exchange channel 221 is heated, so that the heat of the mixed gas after the reaction is utilized, and energy consumption is reduced. The cooled mixed gas is input into the second reaction space 212, and the second stage of the redox reaction occurs under the action of the catalyst layer to further convert the sulfur dioxide into gaseous sulfur. Then the gas is input into the condenser 310, and the condenser 310 condenses the gaseous sulfur.

[0033] It should be noted that, as an example, the above-mentioned catalytic layer is a catalyst layer, and the catalyst can be an iron-cobalt or iron-molybdenum series composite catalyst. It should also be explained that, in this embodiment, the temperature of the catalytic reaction is 400-700°C, and the temperature of the mixed gas input by the first heat exchange channel 221 is relatively low, and the temperature of the mixed gas after the catalytic reaction is relatively high, so the heat exchange between the mixed gas after the reaction and the newly input mixed gas is achieved through the heat exchanger 220 in the tower, so that the temperature of the newly input mixed gas meets the requirements of the catalytic reaction.

[0034] What needs further explanation is that, taking natural gas as an example, the reaction principle of sulfur dioxide and natural gas is shown in the following reaction equation: 2SO2+CH4 2S+CO2+2H2O It can be seen that the mixed gas after the reaction will at least include gaseous sulfur, carbon dioxide and water vapor. At the same time, the mixed gas after the reaction may also contain other sulfur-containing components, which are not limited here.

[0035] By adopting the above-mentioned reduction device 200, the mixed gas after the reaction can exchange heat with the newly input mixed gas in the first heat exchange channel 221 in the second heat exchange channel, so that the temperature of the newly input mixed gas increases and meets the reaction requirements. At the same time, the mixed gas after the reaction is cooled after heat exchange in the heat exchanger 220 in the tower, so that its temperature also meets the reaction requirements of the second stage redox reaction. In this way, the reduction device 200 can realize the heat reuse of the gas after the reaction, improve energy utilization, and reduce costs. By performing two-stage catalytic redox reactions on the mixed gas, the conversion rate of sulfur dioxide can be effectively improved.

[0036] In addition, the heat exchanger 220 in the tower is built into the reduction tower 210, and the integrated design saves floor space and flue gas ducts, reduces equipment costs, and at the same time, the shortening of the flue gas duct reduces heat loss and improves energy utilization.

[0037] It should be explained that, when used for the first time, a preheater 230 can be set before the reduction tower 210. The preheater 230 heats the mixed gas initially input into the first heat exchange channel 221 so that the temperature of the mixed gas initially input meets the reaction requirements. After running for a period of time, the reacted mixed gas can exchange heat with the newly input mixed gas. At this time, the preheater 230 can be turned off or the load of the preheater 230 can be reduced, thereby reducing energy consumption.

[0038] In one embodiment, the second heat exchange channel includes a first sub-channel 222 and a second sub-channel 223, the catalytic layer includes a first catalytic layer 241, a second catalytic layer 242 and a third catalytic layer 243, and the first catalytic layer 241 and the second catalytic layer 242 are arranged at intervals in the first reaction space 211, and the third catalytic layer 243 is arranged in the second reaction space 212.

[0039] The output end of the first heat exchange channel 221 is connected to the inlet of the first catalyst layer 241, so that the newly input mixed gas is transported to the first catalyst layer 241 and the first stage of the redox reaction occurs under the action of the first catalyst layer 241; the outlet of the first catalyst layer 241 is connected to the input end of the first sub-channel 222, so that the mixed gas after the reaction is input into the first sub-channel 222 and heat exchange is performed with the mixed gas in the first heat exchange channel 221; the output end of the first sub-channel 222 is connected to the inlet of the second catalyst layer 242, so that the mixed gas after the heat exchange is input into the first sub-channel 222 and heat exchange is performed with the mixed gas in the first heat exchange channel 221. The second catalytic layer 242 is input, and the first stage redox reaction continues to occur under the action of the second catalytic layer 242; the outlet of the second catalytic layer 242 is connected with the input end of the second sub-channel 223, so that the mixed gas after the reaction is input into the second sub-channel 223 and heat exchanged with the mixed gas in the first heat exchange channel 221; the output end of the second sub-channel 223 is connected with the second reaction space 212, so that the mixed gas after heat exchange is input into the second reaction space 212, and the second stage redox reaction occurs under the action of the third catalytic layer 243. In this way, the conversion rate of sulfur dioxide can be improved, and the heat exchange effect can also be improved.

[0040] Furthermore, the gas in the first heat exchange channel 221 is transported along a first direction, and the first sub-channel 222 and the second sub-channel 223 are arranged in sequence along a second direction opposite to the first direction. In this way, the mixed gas in the second sub-channel 223 can exchange heat with the mixed gas in the upstream section of the first heat exchange channel 221, and the mixed gas in the first sub-channel 222 can exchange heat with the mixed gas in the downstream section of the first heat exchange channel 221, so as to gradually heat the mixed gas in the first heat exchange channel 221 and improve the heating effect. Figure 2 In the illustrated embodiment, the first direction is a vertically upward direction, and the second direction is a vertically downward direction.

[0041] It should be explained that among the first catalytic layer 241, the second catalytic layer 242 and the third catalytic layer 243, the first catalytic layer 241 has the highest reaction efficiency, so the temperature of the mixed gas output from the first reaction space 211 is the highest, and the second catalytic layer 242 has the second highest reaction efficiency, so the temperature of the mixed gas passing through the second catalytic layer 242 is lower than the temperature of the mixed gas passing through the first catalytic layer 241, but both are higher than the catalytic reaction temperature requirement. In this way, the newly input mixed gas is preheated by the mixed gas passing through the second catalytic layer 242, and then the newly input mixed gas is heated again by the mixed gas passing through the first catalytic layer 241, which can improve the heating effect to ensure that the temperature of the newly input mixed gas meets the reaction requirements.

[0042] In one embodiment, the reduction device 200 further includes an external heat exchanger, the output end of the second subchannel 223 is connected to the input end of the external heat exchanger, and the output end of the external heat exchanger is connected to the inlet of the second reaction space 212. Optionally, the external heat exchanger is a waste heat boiler or other equipment capable of heat recycling, which is not limited here.

[0043] It should be noted that most of the heat of the mixed gas passing through the first catalytic layer 241 is transferred to the newly input mixed gas to ensure that the temperature of the newly input mixed gas meets the reaction requirements; the mixed gas passing through the second catalytic layer 242 is used to preheat the newly input mixed gas, so the mixed gas passing through the second catalytic layer 242 can also achieve heat recycling through the external heat exchanger, and it is only necessary to ensure that the temperature of the mixed gas after heat exchange in the external heat exchanger meets the reaction requirements.

[0044] Specific to Figure 2 In the illustrated embodiment, the reduction tower 210 further has a connecting space 213. The first reaction space 211, the connecting space 213 and the second reaction space 212 are arranged in sequence from top to bottom in the vertical direction; the gas in the first heat exchange channel 221 is transported from bottom to top, the first sub-channel 222 and the second sub-channel 223 are arranged at intervals from top to bottom, and the gas inside both is transported from top to bottom. The output end of the second sub-channel 223 is connected to the inlet of the connecting space 213, and the outlet of the connecting space 213 is connected to the input end of the heat exchanger outside the tower. It can be determined that the first reaction space 211, the second reaction space 212 and the connecting space 213 in the reduction tower 210 are isolated from each other and are kept connected through the heat exchange channel or the heat exchanger outside the tower, so that the gas input into the reduction tower 210 is transported along a preset path (such as Figure 2 The gas flow directions of the first heat exchange channel 221, the first sub-channel 222 and the second sub-channel 223 are shown by arrows, but the arrows shown in the figure do not limit the specific positions of the first heat exchange channel 221, the first sub-channel 222 and the second sub-channel 223.

[0045] It can be understood that the provision of the communicating space 213 can facilitate the communication between the heat exchange channel and the heat exchanger outside the tower.

[0046] In one embodiment, a first partition 214 and a second partition 215 are further provided in the reduction tower 210. The first partition 214 and the second partition 215 are arranged in the reduction tower 210 at intervals along the vertical direction. The first partition 214 cooperates with the heat exchanger 220 in the tower to separate the first reaction space 211 in the reduction tower 210. The second partition 215 can separate the second reaction space 212 in the reduction tower 210, and the first partition 214, the heat exchanger 220 in the tower and the second partition 215 are enclosed in the reduction tower 210 to form a connecting space 213. In other words, the first partition 214 and the second partition 215 can separate the first reaction space 211, the connecting space 213 and the second reaction space 212 in the reduction tower 210. Specifically, Figure 2 In the figure, the heat exchanger 220 in the tower is arranged in the middle position of the reduction tower 210, and the first partition 214 includes two layers. The two layers of first partitions 214 are arranged between the heat exchanger 220 in the tower and the inner wall of the reduction tower 210 at intervals in the vertical direction to separate the first catalytic layer 241 from the second catalytic layer 242.

[0047] In one embodiment, the reduction tower 210 is provided with an air inlet, a first air outlet, a reflux port and a second air outlet, the air supply assembly 110 is connected to the air inlet, and a connecting pipe 260 connecting the air inlet and the input end of the first heat exchange channel 221 is provided in the reduction tower 210; the first air outlet is the outlet of the connecting space 213, and the input end of the heat exchanger outside the tower is connected to the first air outlet; the reflux port is the entrance of the second reaction space 212, and the second air outlet is the outlet of the second reaction space 212.

[0048] In one embodiment, the system for resource-based disposal of smelting flue gas further includes an incinerator 320, which is connected to the gas phase output end of the condenser 310. In this way, the sulfur-containing components in the residual gas can be burned back into sulfur dioxide by the incinerator 320, so that the sulfur-containing components can be reused and the sulfur conversion rate can be improved.

[0049] In one embodiment, the system for resource-based disposal of smelting flue gas also includes a liquid storage tank 330 and a production line. The liquid storage tank 330 is connected to the liquid phase output end of the condenser 310 to receive liquid sulfur condensed by the condenser 310; the production line is connected to the liquid storage tank 330 to obtain liquid sulfur and prepare the liquid sulfur into related products, such as solid sulfur.

[0050] Further, the production line includes a granulator 340, a conveyor 350 and a packaging machine 360. The granulator 340 is connected to the liquid storage tank 330 to obtain the liquid sulfur in the liquid storage tank 330, and the granulator 340 can solidify the liquid sulfur and form granular sulfur. The conveyor 350 can transport the granular sulfur prepared by the granulator 340 to the packaging machine 360, and the packaging machine 360 ​​is used to pack the granular sulfur. In this embodiment, the granulator 340 is a belt granulator 340, and low-temperature circulating water is used as a cooling mechanism. Of course, in other embodiments, if the production line is of other types, the condenser 310 can also directly condense the gaseous sulfur into solid sulfur, which is not limited here.

[0051] Furthermore, the conveying device 350 includes a conveying belt, a bucket elevator and a silo. The conveying belt is arranged downstream of the granulator 340 and is used to convey the granulated sulfur to the bucket elevator. The silo is arranged above the packaging machine 360. The bucket elevator is used to lift the granulated sulfur into the silo, and then convey the granulated sulfur to the packaging machine 360 ​​through the silo.

[0052] In order to further understand the technical solution of this application, Figure 1 and Figure 2 The process flow of the system for resource-based disposal of smelting flue gas in the above embodiment is described by taking a specific example: The temperature of the smelting flue gas is 300°C and the concentration of sulfur dioxide is 12%. After the smelting flue gas passes through the scrubber, cooling tower and electric precipitator in sequence, the temperature is reduced to 35°C. Next, it is deoxygenated by the deoxygenation device 140. The temperature of the deoxygenated gas is 50°C, and the main components are sulfur dioxide (concentration of 92.4%) and water (concentration of 7.6%). Next, the deoxygenated gas enters the gas delivery component 110, mixes with natural gas and is input into the reduction tower 210.

[0053] The flow rate of the gas in the reduction tower 210 is 0.5-1.5 m / s, preferably 0.9 m / s, to ensure the reaction effect while ensuring efficiency. The reaction temperature requirement of the first catalytic layer 241, the second catalytic layer 242 and the third catalytic layer 243 is 550-650°C. The mixed gas enters the first reaction space 211 through the first heat exchange channel 221, and first reacts to generate gaseous sulfur under the catalytic action of the first catalytic layer 241; the mixed gas after the reaction enters the first sub-channel 222, and exchanges heat with the newly input mixed gas in the first sub-channel 222, so that the temperature of the newly input mixed gas reaches the reaction temperature requirement, and the temperature of the mixed gas in the first sub-channel 222 is reduced. The mixed gas after cooling enters the second catalytic layer 242, and reacts again under the catalytic action of the second catalytic layer 242. The mixed gas after the second reaction enters the second sub-channel 223, and exchanges heat with the newly input mixed gas in the second sub-channel 223 to achieve preheating of the newly input mixed gas. Then the mixed gas enters the connecting space 213 and enters the external heat exchanger from the connecting space 213 .

[0054] The mixed gas after heat exchange in the heat exchanger outside the tower enters the second reaction space 212, and performs the second stage of oxidation-reduction reaction under the catalytic action of the third catalyst layer 243. The mixed gas after the reaction enters the condenser 310. The condenser 310 condenses the gaseous sulfur into liquid sulfur, and the liquid sulfur is stored in the liquid storage tank 330; the remaining gas is input into the incinerator 320, and the sulfur-containing components are burned into sulfur dioxide by the incinerator 320.

[0055] The liquid sulfur in the liquid storage tank 330 can be pumped to the granulator 340 by a delivery pump, and the granulator 340 cools and solidifies the liquid sulfur to form granular sulfur. Then, the granular sulfur with a temperature of 20-40° C. is delivered to the packaging machine 360 ​​for packaging by the delivery device 350 .

[0056] It should be noted that the heat exchanger 220 in the tower in the above embodiment can be a heat exchanger, which includes all the above-mentioned heat exchange channels; it can also be composed of two heat exchangers arranged up and down, the upper heat exchanger has a first sub-channel 222, the lower heat exchanger has a second sub-channel 223, and there is a directly connected channel between the two heat exchangers to form the above-mentioned first heat exchange channel 221.

[0057] On the other hand, in one embodiment, based on the system for treating smelting flue gas in the above embodiment, the present application also provides a method for treating smelting flue gas in a resource-based manner, comprising the steps of: S110, purifying the smelting flue gas to remove impurities in the smelting flue gas.

[0058] Specifically, the smelting flue gas passes through a washing tower, a cooling tower and an electrostatic precipitator in sequence. Non-metallic impurities such as fluorine and arsenic and metal impurities such as copper and mercury in the smelting flue gas are removed by wet washing. Then, the cooling tower is used to cool the gas and the electrostatic precipitator is used to remove acid mist. The temperature of the purified smelting flue gas is 30-45°C.

[0059] S120, deoxygenating the purified smelting flue gas.

[0060] S130 , mixing the deoxygenated gas with the reducing gas, and inputting the mixed gas into the reducing device 200 .

[0061] Further, the deoxygenated gas enters the gas delivery assembly 110, and the gas supply device 130 inputs the reducing gas into the gas delivery assembly 110, and the two are mixed and input into the reducing device 200 under the action of the gas delivery assembly 110. Specifically, the deoxygenated gas and the reducing gas are mixed in the delivery pipeline, and the mixed gas is guided by the fan to be input into the reducing device 200.

[0062] S140, reducing sulfur dioxide in the mixed gas into gaseous sulfur by the reduction device 200, thereby generating a mixed gas containing gaseous sulfur.

[0063] Specifically, the mixed gas containing sulfur dioxide and reducing gas is input into the reduction tower 210 .

[0064] In the reduction tower 210: the newly input mixed gas enters the first reaction space 211 through the first heat exchange channel 221, and undergoes a first stage redox reaction under the action of the catalyst layer; the mixed gas after the reaction enters the second heat exchange channel and exchanges heat with the mixed gas in the first heat exchange channel 221; the mixed gas after heat exchange enters the second reaction space 212, and undergoes a second stage redox reaction under the action of the catalyst layer.

[0065] Further, the catalytic layer includes a first catalytic layer 241, a second catalytic layer 242 and a third catalytic layer 243; the second heat exchange channel includes a first sub-channel 222 and a second sub-channel 223. Specifically, the newly input mixed gas enters the first catalytic layer 241 through the first heat exchange channel 221, and the first stage of the redox reaction occurs under the action of the first catalytic layer 241. The mixed gas after the reaction enters the first sub-channel 222 and exchanges heat with the mixed gas in the downstream section of the first heat exchange channel 221. The gas after the heat exchange in the first sub-channel 222 enters the second catalytic layer 242, and the first stage of the redox reaction continues to occur under the action of the second catalytic layer 242. The mixed gas after the reaction enters the second sub-channel 223 and exchanges heat with the mixed gas in the upstream section of the first heat exchange channel 221. The mixed gas after the heat exchange in the second sub-channel 223 enters the second reaction space 212, and the second stage of the redox reaction occurs under the action of the third catalytic layer 243.

[0066] It can be understood that the heat exchange between the second sub-channel 223 and the mixed gas in the upstream section of the first heat exchange channel 221 can realize the preheating of the newly input mixed gas, while the heat exchange between the first sub-channel 222 and the mixed gas in the downstream section of the first heat exchange channel 221 can realize the further heating of the preheated mixed gas, thereby improving the heating effect and ensuring that the temperature of the newly input mixed gas meets the reaction requirements.

[0067] It should be further explained that, in this embodiment, the first catalytic layer 241, the second catalytic layer 242 and the third catalytic layer 243 all use an iron-cobalt series composite catalyst or an iron-molybdenum series composite catalyst, and the temperature of the catalytic reaction (i.e., the redox reaction) is 400-700° C. Preferably, the temperature of the catalytic reaction is 550-650° C.

[0068] Furthermore, in Figure 1 In the illustrated embodiment, the mixed gas after heat exchange in the second sub-channel 223 enters the heat exchanger outside the tower, and then enters the second reaction space 212 after further heat exchange.

[0069] S150, the mixed gas containing gaseous sulfur generated after the reaction is condensed, and the condensed liquid sulfur is prepared into a product through a production line, and the non-condensable gas is input into the incinerator 320 for incineration.

[0070] Specifically, in this embodiment, the production line includes a granulator 340, a conveying device 350 and a packaging machine 360. The granulator 340 can obtain liquid sulfur and solidify the liquid sulfur to form granular sulfur. Then the conveying device 350 conveys the granular sulfur at 20-40°C to the packaging machine 360 ​​for packaging.

[0071] In summary, the method and system for resource-based disposal of smelting flue gas provided in this application have at least the following advantages: 1. The smelting flue gas is first purified and deoxygenated before subsequent treatment. Sulfur is prepared using high-concentration sulfur dioxide, which reduces the gas volume of the reduction device 200, reduces equipment specifications, and reduces investment costs. At the same time, no high-temperature dust removal is required in the subsequent process, which prevents dust from entering the sulfur and improves the quality of the sulfur. 2. The catalytic reaction temperature is low and the operating conditions are mild, which can realize continuous production; 3. The heat exchanger 220 in the tower is built into the reduction tower 210. The integrated design saves floor space and flue gas ducts, reduces equipment costs, and shortens the flue gas duct to reduce heat loss and improve energy utilization.

[0072] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for resource disposal of smelting flue gas, characterized in that: Includes steps: Inputting a mixed gas containing sulfur dioxide and reducing gas into a reduction tower; In the reduction tower: the newly input mixed gas enters the first reaction space through the first heat exchange channel, and the first stage of redox reaction occurs under the action of the catalyst layer; the mixed gas after the reaction enters the second heat exchange channel and exchanges heat with the mixed gas in the first heat exchange channel; the mixed gas after heat exchange enters the second reaction space, and the second stage of redox reaction occurs under the action of the catalyst layer; The mixed gas after the reaction in the second reaction space is input into a condenser, and the gaseous sulfur in the mixed gas is condensed by the condenser.

2. The method for recycling smelting flue gas according to claim 1, characterized in that: The second heat exchange channel includes a first sub-channel and a second sub-channel; In the reduction tower: the newly input mixed gas enters the first catalytic layer through the first heat exchange channel, and the first stage of redox reaction occurs under the action of the first catalytic layer. The mixed gas after the reaction enters the first sub-channel and exchanges heat with the mixed gas in the downstream section of the first heat exchange channel. The mixed gas after the heat exchange enters the second catalytic layer, and the first stage of redox reaction continues to occur under the action of the second catalytic layer. The mixed gas after the reaction enters the second sub-channel and exchanges heat with the mixed gas in the upstream section of the first heat exchange channel. The mixed gas after the heat exchange enters the second reaction space, and the second stage of redox reaction occurs under the action of the third catalytic layer.

3. The method for recycling smelting flue gas according to claim 2, characterized in that: The mixed gas after heat exchange in the second sub-channel enters the heat exchanger outside the tower, and then enters the second reaction space.

4. The method for recycling smelting flue gas according to claim 1, characterized in that: The reducing gas is one or more of carbon monoxide, hydrogen, natural gas and hydrogen sulfide; the temperature of the redox reaction is 400-700°C.

5. The method for recycling smelting flue gas according to claim 1, characterized in that: Also includes the steps: S110, purifying smelting flue gas; S120, deoxygenating the purified smelting flue gas; S130, mixing the deoxygenated gas with the reducing gas to form a mixed gas containing sulfur dioxide and the reducing gas.

6. The method for recycling smelting flue gas according to claim 5, characterized in that: In the condenser: the condensed liquid sulfur is used to prepare products through the production line, and the non-condensable gas is input into the incinerator for incineration.

7. A system for resource-based disposal of smelting flue gas, characterized in that: include: A gas delivery component capable of delivering a mixed gas containing sulfur dioxide and reducing gas; A reduction device, comprising a reduction tower and an in-tower heat exchanger, wherein the in-tower heat exchanger is arranged in the reduction tower; The reduction tower has a first reaction space and a second reaction space, and the first reaction space and the second reaction space are both provided with a catalytic layer; the heat exchanger in the tower has a first heat exchange channel and a second heat exchange channel capable of exchanging heat with the first heat exchange channel, and the air supply component is connected to the input end of the first heat exchange channel; The output end of the first heat exchange channel is connected to the inlet of the first reaction space, the outlet of the catalyst layer in the first reaction space is connected to the input end of the second heat exchange channel; the output end of the second heat exchange channel is connected to the inlet of the second reaction space; The system for resource-based disposal of smelting flue gas also includes a condenser, which is connected to the outlet of the second reaction space.

8. The system for recycling smelting flue gas according to claim 7 is characterized in that: The second heat exchange channel includes a first sub-channel and a second sub-channel; the catalytic layer includes a first catalytic layer, a second catalytic layer and a third catalytic layer, the first catalytic layer and the second catalytic layer are arranged in the first reaction space at intervals, and the output end of the first heat exchange channel is connected to the inlet of the first catalytic layer, the outlet of the first catalytic layer is connected to the input end of the first sub-channel, the output end of the first sub-channel is connected to the inlet of the second catalytic layer, the outlet of the second catalytic layer is connected to the input end of the second sub-channel, and the output end of the second sub-channel is connected to the second reaction space; the third catalytic layer is arranged in the second reaction space; The gas in the first heat exchange channel is transported along a first direction, and the first sub-channel and the second sub-channel are arranged in sequence along a second direction opposite to the first direction.

9. The system for recycling smelting flue gas according to claim 8, characterized in that: The reduction device further includes an external heat exchanger, the output end of the second subchannel is communicated with the input end of the external heat exchanger, and the output end of the external heat exchanger is communicated with the inlet of the second reaction space.

10. The system for recycling smelting flue gas according to claim 7, characterized in that: It also includes a purification device, a deoxygenation device and a gas supply device. The purification device is used to purify the gas containing sulfur dioxide and input the purified gas into the deoxygenation device. The deoxygenation device is used to remove oxygen from the gas and input the deoxygenated gas into the gas supply component. The gas supply device is used to input reducing gas into the gas supply component.

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