A process for removing mercury from copper smelting flue gas

Abstract

The present invention relates to a process for demercuring copper smelting flue gas, belonging to the technical field of nonferrous metallurgy. The process comprises the following steps: S1, subjecting the copper smelting flue gas to a purification and acid-making process to produce sulfuric acid and obtain acid-making tail gas; S2, passing the acid-making tail gas obtained in step S1 into a mercury absorption device, while simultaneously passing an absorption liquid for absorbing mercury in the acid-making tail gas into the mercury absorption device to obtain demercured tail gas and demercured circulating liquid; S3, when the mercury content in the demercured tail gas in step S2 is less than 0.012 mg / Nm3, discharging the demercured tail gas; S4, when the demercured circulating liquid in step S2 reaches a set enrichment standard, returning the demercured circulating liquid to the purification and acid-making process. The present invention reduces the mercury content at the flue gas outlet, achieving emission compliance, while also being compatible with existing copper smelting flue gas treatment processes. The waste liquid after demercuration can be fed into the production process, eliminating the need for a post-liquid treatment system.

Description

Technical Field

[0001] The invention relates to a process for removing mercury from copper smelting flue gas, belonging to the technical field of nonferrous metallurgy. Background Art

[0002] Mercury is one of the "five harmful elements" in copper concentrate. Relevant regulations stipulate that the mercury content limit in copper concentrate is 0.01%. Under copper smelting process conditions, mercury will be enriched in the flue gas. Relevant regulations also require that the concentration limit of atmospheric pollutants emitted by copper smelting enterprises is 0.012mg / Nm 3 .

[0003] Flue gas mercury removal technologies at home and abroad mainly include condensation mercury removal technology, adsorption mercury removal technology and oxidation absorption mercury removal technology. However, all of the above mercury removal technologies have major disadvantages:

[0004] 1. The condensation method alone cannot reduce the mercury content to within the national emission standards;

[0005] 2. Mercury removal by adsorption, i.e., adsorbent injection, is currently the most widely used flue gas mercury removal process. However, it is mostly used for mercury removal in coal-fired flue gases from power plants and is less commonly used in the smelting industry. Although activated carbon and modified activated carbon have strong mercury removal capabilities, their high cost makes industrialization difficult. Other inexpensive adsorbents (fly ash, minerals, and calcium-based adsorbents) have limited adsorption capacity and cannot meet purification requirements. Their modification and optimization require further in-depth research.

[0006] 3. Chlorination mercury removal technology is currently mainly used for acid removal of mercury from flue gas in zinc smelting enterprises. Its application scope is relatively narrow and needs to be broadened. This technology requires the construction of a mercury removal reaction tower and supporting systems, which requires a large investment, so it is urgently in need of improvement.

[0007] A Chinese utility model patent with publication number CN204485351U discloses an exhaust gas mercury removal device, comprising: an exhaust gas cooling device having a mercury-containing vapor input terminal, a condensate output terminal, and a condensed exhaust gas output terminal, wherein the mercury-containing vapor input terminal is connected to a device generating mercury-containing exhaust gas, the condensate output terminal outputs cooled and liquefied mercury, and the condensed exhaust gas output terminal discharges condensed exhaust gas; a mercury precipitate collection device connected to the condensate output terminal; an exhaust gas wet mercury removal device connected to the condensed exhaust gas output terminal; a solid precipitate collection device connected to the exhaust gas wet mercury removal device; an exhaust gas adsorption mercury removal device connected to the exhaust gas wet mercury removal device; and a demercured exhaust gas discharge device connected to the exhaust gas adsorption mercury removal device.

[0008] The above-mentioned prior art performs condensation demercuration by setting a condensate output end and a condensed waste gas output end, but it is unable to reduce the mercury content in the copper smelting flue gas to within the national emission standards, and therefore it is in urgent need of improvement. Summary of the Invention

[0009] To overcome the shortcomings of existing mercury removal technologies, such as poor mercury removal effects, inability to meet purification requirements, and a narrow application range due to high requirements for reaction conditions, the present invention designs a copper smelting flue gas mercury removal process. This process reduces the mercury content at the flue gas outlet, achieving emission standards. At the same time, it is compatible with the existing copper smelting flue gas treatment process. After mercury removal, the waste liquid can be re-entered into the production process, eliminating the need for a post-liquid treatment system.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] A process for removing mercury from copper smelting flue gas, comprising the following steps:

[0012] S1. Purifying copper smelting flue gas through an acid-making process to produce sulfuric acid and obtain acid-making tail gas;

[0013] S2, passing the acid-producing tail gas obtained in step S1 into a mercury absorption device, and simultaneously passing an absorption liquid for absorbing mercury in the acid-producing tail gas into the mercury absorption device to obtain mercury-removed tail gas and mercury-removed circulating liquid;

[0014] S3. When the mercury content in the demercured tail gas in step S2 is lower than 0.012 mg / Nm3, the demercured tail gas is discharged;

[0015] S4. When the mercury-removed circulating liquid in step S2 reaches the set enrichment standard, the mercury-removed circulating liquid is refluxed to the purification acid-making process.

[0016] Furthermore, the mercury absorption device includes a reactor, and an air inlet for receiving acid production tail gas and an air outlet for discharging demercuration tail gas are respectively provided at both ends of the reactor; a partition is provided inside the reactor to divide the internal space of the reactor into three independent chambers, each partition is provided with a through hole, and a one-way air permeable membrane is provided in the through hole. The chamber on one side is connected to the air inlet, and the chamber on the other side is connected to the air outlet. The middle chamber is connected to a liquid supply mechanism for inputting the absorption liquid, and a pressurizing device for accelerating the gas circulation inside the reactor is also provided outside the chamber on the side of the air inlet.

[0017] Furthermore, the liquid supply mechanism includes a liquid supply pump and a liquid supply pipe connected to the liquid supply pump, and the liquid supply pipe is extended into the chamber between the two partitions and is connected to a swinging rotary spray device; the swinging rotary spray device includes a mounting assembly fixedly mounted inside the reactor, a liquid spraying mechanism mounted on the mounting assembly and connected to the liquid supply pipe for spraying the atomized absorption liquid, and a swinging drive mechanism mounted on the mounting assembly and used to drive the liquid spraying mechanism to perform reciprocating swinging motion.

[0018] Furthermore, the mounting assembly includes a mounting plate, a transition block and a mounting block which are arranged in sequence as a whole, and the mounting plate, the transition block and the mounting block are arranged perpendicular to each other; the swing drive mechanism includes a rotating motor fixed on one side of the mounting plate, a crank fixedly connected to the output end of the rotating motor, a connecting rod hinged to the free end of the crank, a rocker hinged to the free end of the connecting rod and a rotating rod fixedly sleeved on the free end of the rocker, and one end of the rotating rod rotates through the mounting block and is connected to the liquid spraying mechanism.

[0019] Furthermore, the liquid spraying mechanism includes a connecting pipe, a terminal pipe and an atomizing nozzle. The connecting pipe is connected to the liquid supply pipe. The terminal pipe is vertically fixed at the free end of the connecting pipe. There are several atomizing nozzles, and the several atomizing nozzles are evenly arranged on the terminal pipe.

[0020] Furthermore, the swinging rotary spraying device also includes a reciprocating rotating mechanism for driving the connecting pipe to perform reciprocating rotational motion, and the connecting pipe is rotatably connected to the rotating rod through a rotation limiting mechanism; the reciprocating rotating mechanism includes a limiting frame and a limiting push rod, and the limiting frame includes an integrally arranged fitting block and a fan-shaped frame, the fitting block is arranged between the rocker and the mounting block and is fixedly connected to the mounting block, and a plurality of limiting protrusions are provided on the arc-shaped outer edge of the fan-shaped frame away from the fixed end, the limiting push rod is arranged in an L-shaped structure, and one end of the limiting push rod is fixedly connected to a limiting ring, the limiting ring is fixedly sleeved on the outside of the connecting pipe, and the other end of the limiting push rod is arranged to fit the arc-shaped outer edge of the fan-shaped frame.

[0021] Furthermore, the rotation limiting mechanism includes a connecting plate arranged along the length direction of the connecting tube and fixedly connected to the connecting tube, one end of the connecting plate is fixedly connected to a fixing ring rotatably sleeved on the connecting tube, and the fixing ring is fixedly connected to the rotating rod, and the other end of the connecting plate is fixedly connected to a U-shaped plate, a guide rod is fixedly installed between the two side plates of the U-shaped plate, a swing plate is slidably sleeved on the guide rod, and the swing plate is fixedly connected to the limiting ring.

[0022] Furthermore, the pressurizing device includes a sealing cylinder, a piston, and a U-shaped frame. The U-shaped frame is inverted and fixed on the outer wall of the reactor. The sealing cylinder is fixed between the two fixed ends of the U-shaped frame and is connected to the chamber on the air inlet side. One end of the piston is slidably set inside the sealing cylinder, and the other end extends out of the sealing cylinder. The U-shaped frame is also provided with a reciprocating motion mechanism for driving the piston to reciprocate along the length direction of the sealing cylinder.

[0023] Furthermore, the reciprocating motion mechanism includes a driving motor, a rotating shaft, a cam, a pressure plate and a return spring. The pressure plate is fixed to one end of the piston extending out of the sealing cylinder. The return spring is fixed between the pressure plate and the end of the sealing cylinder. The cam is arranged on the side of the pressure plate away from the sealing cylinder. The rotating shaft is rotatably installed between the two fixed ends of the U-shaped frame and one end passes through the U-shaped frame and is transmission-connected to the driving motor, and the rotating shaft is fixedly arranged through the cam.

[0024] Furthermore, the absorption liquid includes a hydrogen peroxide solution and a dilute sulfuric acid solution, and the mass fractions of the hydrogen peroxide solution and the dilute sulfuric acid solution are both higher than 0.01%.

[0025] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0026] 1. The present invention effectively absorbs mercury vapor in the acid production tail gas by passing the acid production tail gas into a mercury absorption device and introducing an absorption liquid for absorbing mercury in the acid production tail gas into the mercury absorption device, thereby discharging tail gas that meets environmental requirements and meets emission standards. At the same time, by returning the demercured circulating liquid to the purification acid production process, the demercured circulating liquid can be utilized for acid production and the waste liquid treatment step is omitted. On the basis of completing the waste liquid circulation, there is no need to add a waste liquid treatment system, further increasing the applicability of the entire system. In addition, during the entire circulation process, dilute sulfuric acid in the absorption liquid can be produced in the purification acid production process without adding other reagents, thus saving steps and improving efficiency.

[0027] 2. The present invention can concentrate the mercury absorption reaction process in one chamber by setting up a multi-stage chamber in the reactor, which is convenient for subsequent cleaning, and set up a spray mechanism in the reaction chamber that can atomize and spray the absorption liquid, which can effectively increase the mercury absorption rate and improve work efficiency. The setting of the swinging rotary spray device, swinging drive mechanism, reciprocating rotation mechanism, spray mechanism and rotation limit mechanism can not only ensure the multi-angle atomized rotary spraying of the absorption liquid, but also effectively ensure the stability of the device during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow chart of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the mercury absorption device of the present invention;

[0030] Figure 3 This is a schematic structural diagram of the swing jet spraying device of the present invention from a first perspective;

[0031] Figure 4 2. It is a structural schematic diagram of the swing jet spraying device of the present invention from a second viewing angle;

[0032] Figure 53. It is a structural schematic diagram of the swing rotary spraying device of the present invention from a third viewing angle;

[0033] Figure 6 yes Figure 5 A schematic diagram of the local enlarged structure at point A;

[0034] Figure 7 It is a partial structural schematic diagram of the pressurizing device of the present invention.

[0035] The accompanying drawings are denoted as follows:

[0036] 1. Reactor; 101. Air inlet; 102. One-way breathable membrane; 103. Partition; 104. Concentration monitor; 105. Air outlet; 106. Liquid outlet pipe; 107. Stop valve;

[0037] 2. Pressurizing device; 201. Sealing cylinder; 202. Piston; 203. Pressing plate; 204. Return spring; 205. Cam; 206. U-shaped frame; 207. Driving motor; 208. Rotating shaft;

[0038] 3. Liquid supply mechanism; 301. Liquid supply pump; 302. Liquid supply pipe;

[0039] 4. Swinging jet spraying device; 401. Mounting plate; 402. Transition block; 403. Mounting block;

[0040] 5. Swing drive mechanism; 501. Crank; 502. Connecting rod; 503. Rocker; 504. Rotating rod; 505. Rotating motor;

[0041] 6. Reciprocating rotating mechanism; 601. Limiting frame; 602. Limiting protrusion; 603. Limiting push rod; 604. Limiting collar;

[0042] 7. Liquid spray mechanism; 701. Terminal pipe; 702. Atomizing nozzle; 703. Connecting pipe;

[0043] 8. Rotation limiting mechanism; 801. Connecting plate; 802. U-shaped plate; 804. Swinging plate; 805. Guide rod; 806. Fixed collar. DETAILED DESCRIPTION

[0044] The present invention will be described in more detail below with reference to the embodiments.

[0045] Example 1

[0046] See also Figure 1 A process for removing mercury from copper smelting flue gas comprises the following steps:

[0047] S1. Purifying copper smelting flue gas through an acid-making process to produce sulfuric acid and obtain acid-making tail gas;

[0048] S2, passing the acid-producing tail gas obtained in step S1 into a mercury absorption device, and simultaneously passing an absorption liquid for absorbing mercury in the acid-producing tail gas into the mercury absorption device to obtain mercury-removed tail gas and mercury-removed circulating liquid;

[0049] The absorption liquid in step S2 includes a hydrogen peroxide solution and a dilute sulfuric acid solution, the mass fractions of which are both higher than 0.01%. In the subsequent treatment and purification of mercury, only the hydrogen peroxide solution needs to be added. During the recycling and mercury removal process, the sulfuric acid can be produced in-house in step S1. The strong oxidizing property of hydrogen peroxide can convert zero-valent mercury oxygen in the copper smelting flue gas into high-valent mercury, thereby effectively increasing the mercury absorption capacity.

[0050] S3, when the mercury content in the mercury removal tail gas in step S2 is lower than 0.012 mg / Nm 3 When the mercury removal tail gas is discharged;

[0051] S4. When the mercury-removed circulating liquid in step S2 reaches the set enrichment standard, the mercury-removed circulating liquid is returned to the purification acid-making process.

[0052] Specifically, in this embodiment, the temperature of the mercury removal circulating liquid needs to be controlled to be lower than 200°C.

[0053] As can be seen from the above description, the beneficial effects of the present invention are as follows: by passing the acid production tail gas into the mercury absorption device and passing an absorption liquid for absorbing mercury in the acid production tail gas into the mercury absorption device, the mercury vapor in the acid production tail gas can be effectively absorbed, and then the tail gas that meets the safety requirements can be discharged, so that the emission meets the standards. At the same time, by returning the demercured circulating liquid to the purification acid production process, the demercured circulating liquid can be utilized for acid production, and the waste liquid treatment step is also omitted. On the basis of completing the waste liquid circulation, there is no need to add a waste liquid treatment system, which further increases the applicability of the entire system. In addition, during the entire circulation process, dilute sulfuric acid in the absorption liquid can be produced in the purification acid production process without adding other reagents, saving steps and improving efficiency.

[0054] Example 2

[0055] A copper smelting flue gas mercury removal process, based on the above-mentioned embodiment 1, further defines the overall mechanical connection relationship of the mercury absorption device as follows:

[0056] See also Figure 2 and Figure 7The mercury absorption device includes a reactor 1, and an air inlet 101 for receiving acid-producing tail gas and an air outlet 105 for discharging demercuration tail gas are respectively provided at both ends of the reactor 1; a partition 103 is provided inside the reactor 1 to divide the internal space of the reactor 1 into three independent chambers, and each partition 103 is provided with a through hole, and a one-way air permeable membrane 102 is provided in the through hole. One side of the chamber is connected to the air inlet 101, and the other side of the chamber is connected to the air outlet 105. The middle chamber is connected to a liquid supply mechanism 3 for inputting absorption liquid, and a pressurizing device 2 for accelerating the gas circulation inside the reactor 1 is also provided outside the chamber on the side of the air inlet 101.

[0057] Specifically, the three independent chambers are, from left to right, an air inlet chamber, a reaction chamber and an exhaust chamber. After the acid-producing tail gas is introduced into the air inlet chamber, the acid-producing tail gas can be squeezed into the reaction chamber through repeated pressurization by the pressurizing device 2. The one-way breathable membrane 102 is provided to facilitate unidirectional flow of gas and prevent backflow. The liquid supply mechanism 3 is provided to introduce absorption liquid into the reaction chamber for easy absorption. The through port is provided at the upper position of the partition 103, and the liquid supply mechanism 3 is provided at the lower part of the through port, mainly to prevent the absorption liquid from splashing into the air inlet chamber, to ensure that the reaction is only carried out in the reaction chamber, and to facilitate centralized management and cleaning.

[0058] As can be seen from the above description, the air inlet 101 is used to introduce acid-making tail gas, and the air outlet 105 is used to discharge demercuration tail gas. By setting a one-way air permeable membrane 102, gas backflow can be prevented, and the flow direction of the gas can be effectively controlled. By setting the pressurizing device 2, the flow of the gas can be further accelerated. Since the density of the acid-making tail gas containing mercury is relatively large, it generally sinks after entering the reactor 1. Therefore, the setting of the pressurizing device 2 can also squeeze the sunken mercury-containing acid-making tail gas into the reaction chamber, and then effectively absorb it. The setting of the liquid supply mechanism 3 facilitates the supply of absorption liquid to the reaction chamber, and then facilitates the absorption of mercury to meet the environmental protection requirements of the discharged demercuration tail gas. The reaction chamber is separated separately, and the reaction chamber can be effectively monitored, managed and cleaned, thereby improving efficiency.

[0059] In particular, a concentration monitor 104 is provided at the lower part of the liquid supply mechanism 3 in the reaction chamber. The concentration monitor is used to monitor the mercury concentration in the demercuration tail gas. When the mercury content in the demercuration tail gas is lower than

[0060] 0.012mg / Nm 3 When the mercury removal tail gas is discharged, the concentration monitor 104 is connected to the host computer and controlled by the control program of the host computer;

[0061] At the same time, the bottom of the reaction chamber is also connected to a liquid outlet pipe 106, which is provided with a stop valve 107 for discharging the demercuration circulating liquid and connecting the demercuration circulating liquid to the purification acid-making process to achieve self-production of sulfuric acid.

[0062] Furthermore, the pressurizing device 2 includes a sealing cylinder 201, a piston 202, and a U-shaped frame 206. The U-shaped frame 206 is inverted and fixed on the outer wall of the reactor 1. The sealing cylinder 201 is fixed between the two fixed ends of the U-shaped frame 206 and is connected to the chamber on the side of the air inlet 101. One end of the piston 202 is slidably set inside the sealing cylinder 201, and the other end extends out of the sealing cylinder 201. The U-shaped frame 206 is also provided with a reciprocating motion mechanism for driving the piston 202 to reciprocate along the length direction of the sealing cylinder 201.

[0063] As can be seen from the above description, the pressurizing device 2 drives the piston 202 to reciprocate inside the sealing cylinder 201 through the reciprocating motion mechanism, thereby adjusting the air pressure in the air inlet chamber, thereby cooperating with the one-way air permeable membrane 102 to continuously squeeze the gas into the reaction chamber for mercury absorption. The setting of the U-shaped frame 206 facilitates the installation of the reciprocating motion mechanism and has good stability.

[0064] Furthermore, the reciprocating motion mechanism includes a drive motor 207, a rotating shaft 208, a cam 205, a pressure plate 203 and a return spring 204. The pressure plate 203 is fixed to one end of the piston 202 extending out of the sealing cylinder 201. The return spring 204 is fixed between the pressure plate 203 and the end of the sealing cylinder 201. The cam 205 is arranged on the side of the pressure plate 203 away from the sealing cylinder 201. The rotating shaft 208 is rotatably installed between the two fixed ends of the U-shaped frame 206 and one end passes through the U-shaped frame 206 and is transmission-connected to the drive motor 207, and the rotating shaft 208 is fixedly arranged to pass through the cam 205.

[0065] As can be seen from the above description, by starting the drive motor 207, the rotating shaft 208 is driven to rotate, and the rotation of the rotating shaft 208 drives the cam 205 to rotate. The rotation of the cam 205 will continuously squeeze and release the pressure plate 203 in a reciprocating cycle, so that the pressure plate 203 is pressed down and rises with the cooperation of the return spring 204, thereby realizing cyclic pressurization in the air intake chamber. The setting of the reciprocating motion mechanism can effectively squeeze the acid-making tail gas into the reaction chamber. Through the setting of the cam 205, the pressure plate 203 and the return spring 204, efficient, high-precision, reliable and low-maintenance transmission control can be performed.

[0066] Example 3

[0067] A copper smelting flue gas demercuration process, based on the above-mentioned embodiment 2, further defines the overall mechanical connection relationship of the liquid supply mechanism 3 as follows:

[0068] See also Figures 3 to 6The liquid supply mechanism 3 includes a liquid supply pump 301 and a liquid supply pipe 302 connected to the liquid supply pump 301. The liquid supply pipe 302 extends into the chamber between the two partitions 103 and is connected to a swinging rotary spray device 4; the swinging rotary spray device 4 includes a mounting assembly fixedly installed inside the reactor 1, a liquid spraying mechanism 7 installed on the mounting assembly and connected to the liquid supply pipe 302 for spraying atomized absorption liquid, and a swinging drive mechanism 5 installed on the mounting assembly and used to drive the liquid spraying mechanism 7 to perform reciprocating swinging motion.

[0069] Among them, multiple oscillating rotary spraying devices 4 can be set, and can be specifically set according to needs. In this embodiment, two oscillating rotary spraying devices 4 are provided, and are symmetrically fixed on two partitions 103 respectively.

[0070] As can be seen from the above description, by providing the liquid supply pump 301 and the liquid supply pipe 302, it is convenient to introduce the absorption liquid into the reaction chamber, and the swinging rotary spray device 4 is used to spray the absorption liquid, and can perform multi-angle spraying, which can fully react and absorb the mercury-containing acid-making tail gas, and can tell you that the absorption liquid is atomized before being sprayed out, thereby increasing the surface area of ​​the absorption liquid and further increasing the absorption efficiency.

[0071] See also Figure 3 and Figure 4 The mounting assembly includes a mounting plate 401, a transition block 402 and a mounting block 403 which are integrally arranged in sequence, and the mounting plate 401, the transition block 402 and the mounting block 403 are arranged perpendicular to each other in pairs; the swing drive mechanism 5 includes a rotating motor 505 fixed on one side of the mounting plate 401, a crank 501 fixedly connected to the output end of the rotating motor 505, a connecting rod 502 hinged to the free end of the crank 501, a rocker 503 hinged to the free end of the connecting rod 502 and a rotating rod 504 fixedly sleeved on the free end of the rocker 503, and one end of the rotating rod 504 rotates through the mounting block 403 and is connected to the liquid spraying mechanism 7.

[0072] Specifically, the transition block 402 is vertically fixed to the upper portion of one end of the mounting plate 401 , the mounting block 403 is vertically fixed to one side of the top end of the transition block 402 , and the mounting plate 401 is fixedly mounted to the partition plate 103 .

[0073] As can be seen from the above description, by starting the rotating motor 505, the rotating motor 505 drives the crank 501 to rotate, and the rotation of the crank 501 drives one end of the connecting rod 502 to rotate, and then the other end of the connecting rod 502 drives one end of the rocker 503 to swing. During the swinging process of one end of the rocker 503, the other end drives the fixed sleeve rotating rod 504 to rotate. Since the rotating rod 504 rotates and passes through the mounting block 403 and is connected to the liquid spraying mechanism 7, the rotation of the rotating rod 504 can drive the liquid spraying mechanism 7 to rotate, and then the liquid spraying mechanism 7 can spray the absorption liquid to various positions in the reaction chamber, thereby improving the mercury absorption efficiency.

[0074] Furthermore, the liquid spraying mechanism 7 includes a connecting pipe 703, a terminal pipe 701 and an atomizing nozzle 702. The connecting pipe 703 is connected to the liquid supply pipe 302. The terminal pipe 701 is vertically fixed at the free end of the connecting pipe 703. There are several atomizing nozzles 702, and the several atomizing nozzles 702 are evenly arranged on the terminal pipe 701.

[0075] Specifically, the rotating rod 504 rotates through the mounting block 403 and is rotatably connected to the connecting pipe 703 . The rotating rod 504 drives the connecting pipe 703 to swing, thereby realizing rotary spraying.

[0076] From the above description, it can be seen that after the absorption liquid enters the liquid supply pipe 302, it enters the reaction chamber through the connecting pipe 703, the terminal pipe 701 and the atomizing nozzle 702 in sequence, and there are multiple atomizing nozzles 702, which can further increase the injection amount of the absorption liquid and thus improve the absorption efficiency.

[0077] See also Figure 5 and Figure 6 The swinging rotary spraying device 4 also includes a reciprocating rotating mechanism 6 for driving the connecting pipe 703 to perform reciprocating rotation. The connecting pipe 703 is rotatably connected to the rotating rod 504 through a rotation limiting mechanism 8; the reciprocating rotating mechanism 6 includes a limiting frame 601 and a limiting push rod 603. The limiting frame 601 includes an integrally arranged fitting block and a fan-shaped frame. The fitting block is arranged between the rocker 503 and the mounting block 403 and is fixedly connected to the mounting block 403. A plurality of limiting protrusions 602 are provided on the arc-shaped outer edge of the fan-shaped frame away from the fixed end. The limiting push rod 603 is arranged in an L-shaped structure, and one end of the limiting push rod 603 is fixedly connected to the limiting collar 604. The limiting collar 604 is fixedly sleeved on the outside of the connecting pipe 703, and the other end of the limiting push rod 603 is arranged to fit the arc-shaped outer edge of the fan-shaped frame.

[0078] The rotating rod 504 rotates and penetrates the bonding block.

[0079] From the above description, it can be seen that when the rotating rod 504 drives the connecting tube 703 to swing, the other end of the connecting tube 703 will also swing. When the connecting tube 703 swings, it will drive the limiting push rod 603 to swing through the limiting collar 604. During the swinging process, the limiting push rod 603 will touch each limiting protrusion 602 in turn, so that the limiting push rod 603 is moved under the action of the limiting protrusion 602, and then the moving force of the limiting push rod 603 is converted into a rotational force that drives the connecting tube 703 to rotate, so that the connecting tube 703 can further rotate under the premise of continuous swinging, and then drive the terminal tube 701 and the atomizing nozzle 702 to swing and spray at multiple angles, multiple positions, and without dead angles, further improving the absorption efficiency of the absorption liquid.

[0080] In particular, in order to ensure the output stability of the absorption liquid during the rotation and swinging of the connecting pipe 703, the connecting pipe 703 is connected to the liquid supply pipe 302 using a hose with high fatigue strength.

[0081] Furthermore, the rotation limiting mechanism 8 includes a connecting plate 801 arranged along the length direction of the connecting tube 703 and fixedly connected to the connecting tube 703, one end of the connecting plate 801 is fixedly connected to a fixed ring 806 that is rotatably sleeved on the connecting tube 703, and the fixed ring 806 is fixedly connected to the rotating rod 504, and the other end of the connecting plate 801 is fixedly connected to a U-shaped plate 802, and a guide rod 805 is fixedly installed between the two side plates of the U-shaped plate 802, and a swing plate 804 is slidably sleeved on the guide rod 805, and the swing plate 804 is fixedly connected to the limiting ring 604.

[0082] From the above description, it can be seen that by setting the rotation limiting mechanism 8, the connecting tube 703 will drive the connecting plate 801 to swing together during the swinging process, and then the stability of the connecting tube 703 structure is enhanced by the setting of the connecting plate 801. At the same time, the connecting tube 703 will also drive the limiting ring 604 to rotate during the rotation process, and then drive the swing plate 804 to swing along the guide rod 805 through the limiting ring 604, thereby limiting the rotation angle of the connecting tube 703 and improving the connection stability, preventing the connecting tube 703 from falling out, and ensuring the stability of the device during operation.

[0083] The working principle of the present invention is as follows: by passing the acid production tail gas into a mercury absorption device and introducing an absorption liquid for absorbing mercury in the acid production tail gas into the mercury absorption device, the mercury vapor in the acid production tail gas can be effectively absorbed, and then tail gas that meets environmental protection requirements can be discharged, so that the emission meets the standards. At the same time, by returning the demercured circulating liquid to the purification acid production process, the demercured circulating liquid can be utilized for acid production, and the waste liquid treatment step is also omitted. On the basis of completing the waste liquid circulation, there is no need to add a waste liquid treatment system, further increasing the applicability of the entire system. In addition, during the entire circulation process, dilute sulfuric acid in the absorption liquid can be produced in the purification acid production process without adding other reagents, thus saving steps and improving efficiency.

[0084] At the same time, by setting up a multi-stage chamber in the reactor 1, the mercury absorption reaction process can be concentrated in one chamber, which is convenient for subsequent cleaning, and a liquid spraying mechanism 7 that can atomize and spray the absorption liquid is set in the reaction chamber, which can effectively increase the absorption rate of mercury and improve work efficiency. The setting of the swinging rotary spraying device 4, the swinging driving mechanism 5, the reciprocating rotation mechanism 6, the liquid spraying mechanism 7 and the rotation limiting mechanism 8 can ensure the multi-angle atomized rotary spraying of the absorption liquid while effectively ensuring the stability of the device during operation.

[0085] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0086] In the description of the present invention, it should be noted that, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0087] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. A process for removing mercury from copper smelting flue gas, characterized by: The steps include: S1. Purifying copper smelting flue gas through an acid-making process to produce sulfuric acid and obtain acid-making tail gas; S2, passing the acid-producing tail gas obtained in step S1 into a mercury absorption device, and simultaneously passing an absorption liquid for absorbing mercury in the acid-producing tail gas into the mercury absorption device to obtain mercury-removed tail gas and mercury-removed circulating liquid; S3. When the mercury content in the demercured tail gas in step S2 is lower than 0.012 mg / Nm3, the demercured tail gas is discharged; S4. When the mercury-removed circulating liquid in step S2 reaches the set enrichment standard, the mercury-removed circulating liquid is refluxed to the purification acid-making process; The mercury absorption device comprises a reactor (1), wherein both ends of the reactor (1) are respectively provided with an air inlet (101) for receiving acid production tail gas and an air outlet (105) for discharging demercured tail gas; a partition (103) is provided inside the reactor (1) to divide the internal space of the reactor (1) into three independent chambers, each partition (103) is provided with a through hole, and a one-way air permeable membrane (102) is provided in the through hole; the chamber on one side is connected to the air inlet (101), and the chamber on the other side is connected to the air outlet (105); the middle chamber is connected to a liquid supply mechanism (3) for inputting the absorption liquid, and a pressurizing device (2) for accelerating the gas circulation inside the reactor (1) is further provided outside the chamber on the side of the air inlet (101); The liquid supply mechanism (3) comprises a liquid supply pump (301) and a liquid supply pipe (302) connected to the liquid supply pump (301); the liquid supply pipe (302) extends into the chamber between the two partitions (103) and is connected to the swing rotary spray device (4); the swing rotary spray device (4) comprises a mounting assembly fixedly mounted inside the reactor (1), a liquid spray mechanism (7) mounted on the mounting assembly and connected to the liquid supply pipe (302) for spraying the atomized absorption liquid, and a swing drive mechanism (5) mounted on the mounting assembly and for driving the liquid spray mechanism (7) to perform reciprocating swinging motion.

2. The process for removing mercury from copper smelting flue gas according to claim 1, characterized in that: The mounting assembly comprises a mounting plate (401), a transition block (402) and a mounting block (403) which are integrally arranged in sequence, and the mounting plate (401), the transition block (402) and the mounting block (403) are arranged perpendicular to each other in pairs; the swing drive mechanism (5) comprises a rotating motor (505) fixed to one side of the mounting plate (401), a crank (501) fixedly connected to the output end of the rotating motor (505), a connecting rod (502) hinged to the free end of the crank (501), a rocker (503) hinged to the free end of the connecting rod (502), and a rotating rod (504) fixedly sleeved on the free end of the rocker (503), wherein one end of the rotating rod (504) rotates through the mounting block (403) and is connected to the liquid spraying mechanism (7).

3. The process for removing mercury from copper smelting flue gas according to claim 2, characterized in that: The liquid spraying mechanism (7) comprises a connecting pipe (703), a terminal pipe (701) and an atomizing nozzle (702); the connecting pipe (703) is connected to the liquid supply pipe (302); the terminal pipe (701) is vertically fixed to the free end of the connecting pipe (703); a plurality of atomizing nozzles (702) are provided, and the plurality of atomizing nozzles (702) are evenly arranged on the terminal pipe (701).

4. The process for removing mercury from copper smelting flue gas according to claim 3, characterized in that: The swing jet device (4) further comprises a reciprocating rotation mechanism (6) for driving the connecting pipe (703) to perform reciprocating rotational motion, wherein the connecting pipe (703) is rotationally connected to the rotating rod (504) via a rotation limiting mechanism (8); the reciprocating rotation mechanism (6) comprises a limiting frame (601) and a limiting push rod (603), wherein the limiting frame (601) comprises an integrally arranged fitting block and a fan-shaped frame, wherein the fitting block is arranged between the rocking rod (503) and the mounting block. (403) and is fixedly connected to the mounting block (403), a plurality of limiting protrusions (602) are provided on the arc-shaped outer edge of the sector frame away from the fixed end, the limiting push rod (603) is arranged in an L-shaped structure, and one end of the limiting push rod (603) is fixedly connected to the limiting collar (604), the limiting collar (604) is fixedly sleeved outside the connecting tube (703), and the other end of the limiting push rod (603) is arranged in contact with the arc-shaped outer edge of the sector frame.

5. The process for removing mercury from copper smelting flue gas according to claim 4, characterized in that: The rotation limiting mechanism (8) comprises a connecting plate (801) arranged along the length direction of the connecting tube (703) and fixedly connected to the connecting tube (703); one end of the connecting plate (801) is fixedly connected to a fixing ring (806) that is rotatably sleeved with the connecting tube (703); the fixing ring (806) is fixedly connected to the rotating rod (504); the other end of the connecting plate (801) is fixedly connected to a U-shaped plate (802); a guide rod (805) is fixedly installed between the two side plates of the U-shaped plate (802); a swing plate (804) is slidably sleeved on the guide rod (805); and the swing plate (804) is fixedly connected to the limiting ring (604).

6. The process for removing mercury from copper smelting flue gas according to claim 1, characterized in that: The pressurizing device (2) comprises a sealing cylinder (201), a piston (202), and a U-shaped frame (206). The U-shaped frame (206) is fixed upside down on the outer wall of the reactor (1). The sealing cylinder (201) is fixed between the two fixed ends of the U-shaped frame (206) and is connected to the chamber on one side of the air inlet (101). One end of the piston (202) is slidably arranged inside the sealing cylinder (201), and the other end is extended out of the sealing cylinder (201). A reciprocating motion mechanism is also provided on the U-shaped frame (206) for driving the piston (202) to reciprocate along the length direction of the sealing cylinder (201).

7. The process for removing mercury from copper smelting flue gas according to claim 6, characterized in that: The reciprocating motion mechanism comprises a driving motor (207), a rotating shaft (208), a cam (205), a pressure plate (203) and a return spring (204), wherein the pressure plate (203) is fixed to one end of the piston (202) extending out of the sealing cylinder (201), the return spring (204) is fixed between the pressure plate (203) and the end of the sealing cylinder (201), the cam (205) is arranged in contact with the side of the pressure plate (203) away from the sealing cylinder (201), the rotating shaft (208) is rotatably mounted between two fixed ends of the U-shaped frame (206), and one end passes through the U-shaped frame (206) and is transmission-connected to the driving motor (207), and the rotating shaft (208) is fixedly arranged to pass through the cam (205).

8. The process for removing mercury from copper smelting flue gas according to claim 1, characterized in that: The absorption liquid includes a hydrogen peroxide solution and a dilute sulfuric acid solution, and the mass fractions of the hydrogen peroxide solution and the dilute sulfuric acid solution are both higher than 0.01%.

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