Lightweight high-temperature-resistant low-antimony lead-silver-bismuth separation and recovery device and method

Abstract

This invention relates to the field of silver-bismuth separation and recovery technology, specifically to a lightweight, high-temperature resistant, low-antimony bottom lead-silver-bismuth separation and recovery device and method. It includes a lightweight heating furnace body with a high-temperature furnace chamber inside, and a temperature control platform integrated at its bottom; a high-temperature resistant crucible that can be removably embedded in the high-temperature furnace chamber; a furnace cover that covers the top of the high-temperature resistant crucible; a material distribution assembly including a storage bin and a uniform distribution plate; a high-temperature resistant gas pipe with a microporous gas distributor integrally connected to its lower end; the storage bin having an annular valve; the uniform distribution plate being rotatably mounted at the bottom of the furnace cover and having material troughs evenly distributed along its circumference; and the furnace cover having several material drop channels evenly distributed along its circumference. This invention quantitatively releases chloride salt through the annular valve. The salt falls into the sloping uniform distribution plate and is evenly distributed on the surface of the molten lead during rotation. Simultaneously, air is blown in through the high-temperature resistant gas pipe to complete oxidation, achieving efficient and safe separation of silver and bismuth.

Description

Technical Field

[0001] This invention relates to the field of silver-bismuth separation and recovery technology, specifically to a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device and method. Background Technology

[0002] In the field of precious metal smelting and recycling, crude lead, especially low-antimony lead, often contains valuable metals such as silver and bismuth. Silver enrichment and recovery require steps such as oxidation to remove antimony and chlorination to remove bismuth. Traditional processes often employ large reverberatory furnaces or rotary furnaces, sequentially performing blast oxidation and molten salt chlorination at high temperatures. While this achieves metal separation, it suffers from problems such as bulky equipment, high energy consumption, long processes, and large infrastructure investments, making it unsuitable for small-batch, decentralized recycling scenarios.

[0003] While existing small gold melting furnaces are portable, they generally lack airtightness and precise control: the oxidation stage relies on manual ventilation, which can easily lead to over-oxidation or uneven reaction. Bismuth removal via chlorination often involves directly adding solid chloride salts, which causes the salts to splash and volatilize instantly upon contact with the high-temperature molten lead, resulting in significant losses. This not only reduces bismuth removal efficiency but also introduces operational safety hazards and fluctuations in silver recovery rates.

[0004] Therefore, there is a need for a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device that integrates controllable oxidation and uniform chlorination functions to effectively solve the problems of salt splashing, uneven reaction, low bismuth removal efficiency, and large silver loss caused by the crude feeding method in existing smelting equipment. Summary of the Invention

[0005] To address the problems existing in the prior art, a lightweight, high-temperature resistant, low-antimony bottom lead-silver-bismuth separation and recovery device is provided. Chloride salt is quantitatively released through an annular valve. The salt falls into a uniform distribution plate with a sloping surface through a material discharge channel and is evenly distributed on the surface of molten lead during rotation. At the same time, air is blown in through a high-temperature resistant gas pipe to complete oxidation, and the liquid surface is disturbed at low speed by a stirring bar to promote the volatilization of bismuth chloride, thereby achieving efficient and safe separation of silver and bismuth.

[0006] To address the problems of existing technologies, this invention provides a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device, comprising a lightweight heating furnace body with a high-temperature furnace chamber inside and a temperature control platform integrated at its bottom; a high-temperature resistant crucible, removably embedded in the high-temperature furnace chamber for holding crude lead and smelting; a furnace lid covering the top of the high-temperature resistant crucible and capable of moving up and down along the crucible's axial direction; and a feeding assembly mounted on the furnace lid, including a storage bin and a uniform feeding tray below it for evenly distributing solid chloride salts onto the surface of the molten lead. A heat pipe is coaxially installed in the center of the storage silo. Its upper end is connected to an external gas source, and its lower end passes through the furnace cover and is integrally connected to a microporous gas distributor for blowing reaction gas into the molten lead in the high-temperature crucible. The storage silo is fixed to the top of the furnace cover and has an annular valve coaxial with the heat pipe. The material distribution plate is rotatably installed at the bottom of the furnace cover and has material troughs evenly distributed along its circumference. The furnace cover has several material drop channels evenly opened along its circumference, connecting the storage silo and the material distribution plate. The side of the lightweight heating furnace body is provided with a lifting drive for driving the furnace cover to move.

[0007] Preferably, the material trough is opened radially along the material distribution plate, and the upper surface of the material distribution plate is provided with a sloping surface inclined towards each material trough, which is used to guide the salt material to slide smoothly into the material trough under the action of gravity and to spread evenly in the circumference as the material distribution plate rotates.

[0008] Preferably, the center of the uniform material tray is provided with a bushing fitted on the high-temperature resistant gas pipe, the outer periphery of the high-temperature resistant gas pipe is provided with a stirring bar extending along its axial direction, and the bushing is provided with an axial groove corresponding to the stirring bar.

[0009] Preferably, the high-temperature resistant gas pipe is axially movable along the material distribution plate, and a guide sleeve is provided on the furnace cover extending vertically upward and fitted onto the high-temperature resistant gas pipe. The upper end of the guide sleeve is provided with a rotary connecting pipe extending vertically downward and axially engaging with the high-temperature resistant gas pipe, which is used to transmit rotational power and allow axial relative displacement.

[0010] Preferably, the upper end of the bushing is provided with a pivot ring that rotates with the furnace cover, and the lower end is provided with a slag-cleaning ring that fits tightly against the outer surface of the high-temperature resistant gas pipe and the side of the stirring bar.

[0011] Preferably, a guide cavity is formed between the guide sleeve and the rotary connecting pipe, a piston is provided at the upper end of the high-temperature resistant gas pipe and embedded in the guide cavity, a compression spring is provided between the piston and the bottom of the guide cavity, and a pressure inlet and a pressure outlet are provided at the upper part of the guide sleeve, which are respectively connected to the guide cavity.

[0012] Preferably, the storage silo is an annular cavity with an open top, and the annular valve inside is a conical valve structure with a sealing contact surface that can fit against the inner wall of the storage silo. The furnace cover is provided with a valve actuator for driving the opening and closing of the annular valve.

[0013] Preferably, the valve actuator includes a fixed electromagnet and a movable electromagnet located above it. The fixed electromagnet is fixedly connected to the furnace cover, and the movable electromagnet is fixedly connected to the annular valve. A return spring is fixedly connected between the fixed electromagnet and the movable electromagnet.

[0014] Preferably, the lightweight heating furnace body is provided with a breathable protective net on its outer periphery, and an annular heat dissipation gap is left between the breathable protective net and the outer surface of the lightweight heating furnace body.

[0015] This invention also provides a lightweight, high-temperature resistant, low-antimony-containing method for the separation and recovery of lead, silver, and bismuth, comprising the following steps:

[0016] S1. Load the low-antimony crude lead into a high-temperature resistant crucible and place it in a lightweight heating furnace. Then close the furnace lid and heat it to 900°C to completely melt the lead.

[0017] S2. Air is blown in through a microporous gas distributor and oxidized at 850–920℃ for 10–30 minutes to oxidize the residual antimony into antimony trioxide.

[0018] S3. Start the valve actuator to open the annular valve, drive the uniform material plate to rotate, and evenly spread the chloride salt material on the surface of the molten lead through the material tank. Heat to 950℃ and keep it at that temperature for 15–30 minutes to convert bismuth into bismuth trichloride and volatilize it.

[0019] S4. After the reaction is complete, the lifting drive raises the furnace cover, removes the high-temperature resistant crucible, separates the upper layer of molten salt slag, pours the lower layer of silver-rich lead liquid, and recovers the high-silver lead ingot.

[0020] The advantages of this application compared to the prior art are:

[0021] 1. This invention places a high-temperature resistant crucible inside a high-temperature furnace cavity within a lightweight heating furnace body, with precise temperature control via a bottom temperature control platform. The furnace lid automatically opens and closes under the action of a lifting drive. During operation, the integrated material spreading component allows chloride salts to fall into a uniform material tray through an open annular valve, slide down a slope into a material trough under gravity, and be evenly spread onto the surface of the molten lead as the uniform material tray rotates.

[0022] Simultaneously, air is blown in through a coaxial high-temperature resistant gas tube via a microporous gas distributor to complete the initial oxidation. The entire process is completed automatically in a closed environment without human intervention, ensuring efficient bismuth chlorination and volatilization, and silver enrichment in the lead phase, thereby improving separation efficiency and operational safety.

[0023] 2. This invention utilizes the engagement of a stirring bar on the outer periphery of a high-temperature resistant gas pipe with an axial groove within a bushing to synchronously transmit the torque from the rotary drive source via a rotary connecting pipe to the uniform distribution plate, achieving uniform salt distribution. Simultaneously, the stirring bar agitates the molten lead surface at low speed, promoting the chlorination reaction without causing splashing.

[0024] The lifting and lowering of the high-temperature resistant gas tube is controlled by a pneumatic system consisting of a piston inside the guide sleeve, a compression spring, a pressurization port, and a depressurization port. During pressurization, the high-temperature resistant gas tube moves downward, immersing the microporous gas distributor into the molten lead. After depressurization, the spring returns to its original position, causing the high-temperature resistant gas tube to rise. During the rising process, the slag-removing ring fixed to the lower end of the bushing adheres closely to the surface of the high-temperature resistant gas tube and the stirring bar, automatically scraping off the attached molten salt and residue, thus improving bismuth removal efficiency and operational reliability.

[0025] 3. This invention achieves precise dosing and reliable sealing of chloride salt by installing a conical valve structure annular valve and an electromagnetically driven valve actuator at the bottom of the storage silo. When energized, the fixed electromagnet attracts the movable electromagnet, causing the annular valve to move downward and close the valve port. When reverse-energized, the annular valve moves upward and opens under the action of magnetic force, forming a controllable annular flow channel to ensure that the salt is released quantitatively as needed.

[0026] When storing materials in the storage silo, the salt is spread evenly in it. After the valve is opened, the salt is evenly passed through the annular valve under the action of gravity and falls into the material distribution plate below through the material drop channel on the furnace cover. This provides a stable and continuous material supply for subsequent rotating material distribution, improves the uniformity of salt distribution, ensures that the chlorination reaction is carried out synchronously and fully on the entire molten lead surface, effectively avoids local over-discharge or under-discharge, and thus improves the bismuth removal efficiency and the purity of silver-lead products. Attached Figure Description

[0027] Figure 1 This is a three-dimensional structural diagram of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device of the present invention with the furnace cover closed.

[0028] Figure 2 This is a three-dimensional structural diagram of the furnace lid of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device of the present invention in the open state.

[0029] Figure 3 This is a partial three-dimensional structural cross-sectional view of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to the present invention.

[0030] Figure 4 This is a partial planar cross-sectional view of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to the present invention.

[0031] Figure 5 This is a three-dimensional exploded view of the lightweight heating furnace body, high-temperature resistant crucible, and material spreading assembly of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device of the present invention.

[0032] Figure 6 This is a three-dimensional structural diagram of the feeding component of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to the present invention.

[0033] Figure 7 This is a three-dimensional exploded view of the material spreading component of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to the present invention.

[0034] Figure 8 This is a three-dimensional structural diagram of the furnace cover, high-temperature resistant gas pipe, and rotary connecting pipe of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to the present invention.

[0035] Figure 9 This is a three-dimensional structural diagram of the uniform material tray and furnace cover of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device of the present invention from a first perspective.

[0036] Figure 10 This is a three-dimensional structural diagram of the uniform material tray and furnace cover of a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device of the present invention from a second perspective.

[0037] The following components are labeled in the diagram: 1. Lightweight heating furnace body; 11. Temperature control platform; 12. Breathable protective net; 2. High-temperature resistant crucible; 3. Furnace cover; 31. Material discharge channel; 32. Guide sleeve; 321. Pressurization port; 322. Pressure relief port; 33. Rotary connecting pipe; 4. Material spreading assembly; 41. Storage bin; 411. Annular valve; 4111. Fixed electromagnet; 4112. Movable electromagnet; 4113. Return spring; 42. Floating plate; 421. Material trough; 422. Sloping surface; 423. Bushing; 4231. Pivot ring; 4232. Slag removal ring; 5. High-temperature resistant gas pipe; 51. Microporous gas distributor; 52. Stirring bar; 53. Piston; 531. Compression spring; 6. Lifting actuator. Detailed Implementation

[0038] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0039] See Figures 1 to 5As shown, a lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device includes a lightweight heating furnace body 1, which has a high-temperature furnace chamber inside and a temperature control platform 11 integrated at its bottom. A high-temperature resistant crucible 2 is removably embedded in the high-temperature furnace chamber for holding crude lead and smelting it. A furnace cover 3 covers the top of the high-temperature resistant crucible 2 and can move up and down along the axial direction of the high-temperature resistant crucible 2. A feeding assembly 4 is installed on the furnace cover 3 and includes a storage bin 41 and a uniform feeding plate 42 located below it, for uniformly spreading solid chloride salts on the surface of the molten lead. A high-temperature resistant gas pipe 5 is coaxially arranged through the center of the storage bin 41, with its upper end connected to an external gas source and its lower end passing through the furnace cover 3 and integrally connected to a microporous gas distributor 51, for blowing reaction gas into the molten lead in the high-temperature resistant crucible 2. The storage bin 41 is fixed to the top of the furnace cover 3 and has an annular valve 411 coaxial with the high-temperature resistant gas pipe 5. The material distribution plate 42 is rotatably mounted at the bottom of the furnace cover 3 and has material troughs 421 evenly distributed along its circumference. The furnace cover 3 has several material drop channels 31 evenly distributed along its circumference, connecting the storage bin 41 and the material distribution plate 42. The lightweight heating furnace body 1 has a lifting drive 6 on its side for driving the furnace cover 3 to move.

[0040] The lifting drive 6 is a lead screw slide structure.

[0041] During operation, a high-temperature resistant crucible 2 containing low-antimony crude lead is first placed in the high-temperature furnace chamber inside the lightweight heating furnace body 1, with the bottom of the crucible in close contact with the temperature control platform 11 integrated at the bottom of the furnace body. Then, the furnace lid 3 descends from above and closes on top of the high-temperature resistant crucible 2, completing the sealing of the crucible opening. The furnace lid 3 is not fixed in place; instead, it moves vertically along the crucible's axis via a lifting actuator 6 located on the side of the lightweight heating furnace body 1, precisely controlling the opening and closing position of the furnace lid 3.

[0042] When the furnace cover 3 is closed, the feeding assembly 4 installed on it is in place. The storage bin 41 at the top of the furnace cover 3 is pre-filled with solid chloride salt. A high-temperature resistant gas pipe 5 is coaxially installed through the center of the storage bin 41, and the microporous gas distributor 51 at the lower end extends below the molten lead surface inside the high-temperature crucible 2. When salt needs to be added, the annular valve 411 at the bottom of the storage bin 41 is opened, and the salt flows down from the storage bin 41 through several circumferentially evenly distributed dropping channels 31 on the furnace cover 3, falling onto the uniform distribution plate 42 at the bottom of the furnace cover 3.

[0043] As the equalizing plate 42 rotates, the salt is distributed into each feed tank 421 and finally evenly spread on the surface of the molten lead below. Before the reaction begins, the furnace lid 3 lowers and presses down on the high-temperature resistant crucible 2 to form a sealed space. After the reaction ends, the furnace lid 3 rises smoothly, completely exposing the top of the high-temperature resistant crucible 2, allowing operators to remove the crucible 2 as a whole without obstruction for subsequent processing, thus achieving efficient separation and recovery of silver and bismuth from low-antimony crude lead.

[0044] In a closed and controlled high-temperature environment, residual antimony is first oxidized by a microporous gas distributor 51. Then, with the cooperation of a uniform feeding plate 42 and a feeding channel 31, chloride salts are evenly distributed on the surface of the molten lead, promoting the selective conversion of bismuth into bismuth trichloride, which then volatilizes and is removed, while silver is enriched in the lead phase. The entire process does not require manual opening of the lid for feeding or stirring, avoiding splashing, over-oxidation, and operational risks. Ultimately, high-purity silver-rich lead ingots are obtained, improving the precious metal recovery rate, process safety, and ease of equipment operation.

[0045] See Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, the material trough 421 is opened radially along the material distribution plate 42. The upper surface of the material distribution plate 42 is provided with a sloping surface 422 inclined towards each material trough 421, which is used to guide the salt material to slide smoothly into the material trough 421 under the action of gravity and to be evenly spread circumferentially as the material distribution plate 42 rotates.

[0046] During the feeding process, the solid chloride salt falls from the storage bin 41 through the material drop channel 31 on the furnace cover 3 and first lands on the upper surface of the uniform distribution plate 42. Since the upper surface of the uniform distribution plate 42 is designed as a sloping surface 422 inclined towards each material trough 421, the salt naturally slides down the sloping surface 422 under the action of gravity and quickly gathers into the radially opened material trough 421.

[0047] As the uniform material tray 42 rotates continuously around its central axis, the radial material troughs 421 move in a circular motion, carrying the introduced salt to different positions. Under the combined action of centrifugal force and gravity, the salt slides from the material troughs 421 to the molten lead surface below. Without the need for additional vibration or forced pushing mechanisms, the salt can be uniformly distributed circumferentially across the entire surface of the high-temperature crucible 2 using only geometric inclined planes and rotational motion. This effectively avoids local accumulation or uneven reaction, improving the efficiency of bismuth removal by chloride and the stability of the process.

[0048] See Figures 3 to 10 As shown, the center of the uniform material plate 42 is provided with a bushing 423 sleeved on the high temperature resistant gas pipe 5, and the outer periphery of the high temperature resistant gas pipe 5 is provided with a stirring strip 52 extending along its axial direction. The bushing 423 is provided with an axial groove that cooperates with the stirring strip 52.

[0049] When the high-temperature resistant gas pipe 5 rotates, the stirring bar 52 on its outer periphery rotates accordingly. By contacting the side wall of the axial groove provided on the inner wall of the bushing 423, the rotational torque is effectively transmitted to the bushing 423, thereby driving the entire uniform material plate 42 to rotate synchronously.

[0050] While the uniform distribution of salt is achieved by the rotation of the uniform distribution plate 42, the stirring bar 52 slowly stirs the surface of molten lead in the high-temperature crucible 2 at a low speed, generating gentle turbulence. This promotes full contact between the chloride salt and the molten lead, while avoiding splashing or increased oxidation caused by vigorous stirring. Thus, while ensuring the uniformity of distribution, the selective chlorination efficiency of bismuth is further improved.

[0051] See Figures 3 to 10 As shown, the high-temperature gas pipe 5 can move axially along the material distribution plate 42. A guide sleeve 32 extends vertically upward on the furnace cover 3 and is sleeved on the high-temperature gas pipe 5. The upper end of the guide sleeve 32 is provided with a rotating connecting pipe 33 that extends vertically downward and is axially engaged with the high-temperature gas pipe 5, which is used to transmit rotational power and allow axial relative displacement.

[0052] The rotary drive source used to drive the rotary connecting pipe 33 is not shown in the figure.

[0053] During the operation of the device, the rotary connecting pipe 33 and the high-temperature gas pipe 5 are circumferentially linked through an axial snap-fit ​​structure, such as a keyway, so that the torque applied by the external rotary drive source can be reliably transmitted to the high-temperature gas pipe 5 through the rotary connecting pipe 33, driving it and the microporous gas distributor 51 and the stirring bar 52 at the lower end to rotate synchronously.

[0054] Meanwhile, the snap-fit ​​structure allows the high-temperature gas pipe 5 to slide up and down axially relative to the rotating connecting pipe 33 and the guide sleeve 32 when driven by external force, thereby achieving the lifting and lowering adjustment of the high-temperature gas pipe 5 in the high-temperature crucible 2 while maintaining continuous rotational power transmission, and meeting the process requirements of the gas distributor immersion depth at different reaction stages.

[0055] See Figures 6 to 10 As shown, the upper end of the bushing 423 is provided with a pivot ring 4231 that rotates with the furnace cover 3, and the lower end is provided with a slag cleaning ring 4232 that fits tightly with the outer surface of the high-temperature gas pipe 5 and the side of the stirring bar 52.

[0056] During the reaction process, the bushing 423 forms a rotational fit with the furnace cover 3 through the pivot ring 4231 at its upper end, so that the uniform material plate 42 can rotate stably at the bottom of the furnace cover 3.

[0057] Meanwhile, after the reaction is complete, the high-temperature resistant gas tube 5 moves upward along the axial direction and is lifted from the surface of the molten lead. At this time, the cleaning ring 4232, due to its close contact with the outer surface of the high-temperature resistant gas tube 5 and the side of the stirring bar 52, scrapes the surfaces of both as the high-temperature resistant gas tube 5 moves upward. As the high-temperature resistant gas tube 5 continues to rise, the cleaning ring 4232 scrapes away the molten salt, oxide slag, or condensed residue adhering to its outer wall and the side of the stirring bar 52 layer by layer, achieving automatic cleaning.

[0058] See Figures 3 to 5 As shown, a guide cavity is formed between the guide sleeve 32 and the rotary connecting pipe 33. The upper end of the high-temperature resistant gas pipe 5 is provided with a piston 53 embedded in the guide cavity. A compression spring 531 is provided between the piston 53 and the bottom of the guide cavity. The upper part of the guide sleeve 32 is provided with a pressure port 321 and a pressure relief port 322 that are respectively connected to the guide cavity.

[0059] When the microporous gas distributor 51 needs to be immersed in the molten lead, compressed gas is introduced into the guide cavity through the pressure port 321 on the upper part of the guide sleeve 32. The gas pressure acts on the top of the piston 53, overcoming the elastic force of the compression spring 531, and pushing the piston 53 and the high-temperature resistant gas pipe 5 connected to it to move downward synchronously.

[0060] After the reaction is complete, the pressure relief port 322 is opened to release the internal pressure, the compression spring 531 resets, and the piston 53 and the high-temperature resistant air pipe 5 automatically rise. The entire lifting process is completed in the sealed guide cavity, which not only ensures the smoothness and coaxiality of the movement, but also achieves reliable control with no motor and low maintenance through pneumatic drive and spring reset.

[0061] See Figure 3 and Figure 4 As shown, the storage bin 41 is an annular cavity with an open top. The annular valve 411 inside is a conical valve structure with a sealing contact surface that can fit against the inner wall of the storage bin 41. The furnace cover 3 is provided with a valve actuator for driving the opening and closing of the annular valve 411.

[0062] During operation, solid chloride salt is added from above into an annular cavity storage silo 41 with an open top. The cone valve structure at the bottom of the storage silo 41 serves as an annular valve 411. When closed, its cone surface fits tightly against the inner wall of the storage silo 41, forming a reliable sealing contact surface and effectively preventing accidental leakage of salt.

[0063] When salt needs to be added, the valve actuator on the furnace cover 3 is activated, which drives the annular valve 411 to move upward, so that its conical surface separates from the inner wall of the storage bin 41, forming an annular valve port between the annular valve 411 and the storage bin 41, and the salt flows out evenly through the valve port.

[0064] After feeding is completed, the valve actuator reverses its action, driving the annular valve 411 to reset and re-tighten the sealing contact surface, achieving rapid and tight closure, providing a stable basis for precise control of chloride addition.

[0065] See Figure 3 and Figure 4 As shown, the valve actuator includes a fixed electromagnet 4111 and a movable electromagnet 4112 located above it. The fixed electromagnet 4111 is fixedly connected to the furnace cover 3, and the movable electromagnet 4112 is fixedly connected to the annular valve 411. A return spring 4113 is fixedly connected between the fixed electromagnet 4111 and the movable electromagnet 4112.

[0066] During the valve actuator startup process, the annular valve 411 is opened and closed by electromagnetic action. When the fixed electromagnet 4111 and the movable electromagnet 4112 are energized, the fixed electromagnet 4111 generates a magnetic attraction force, which attracts the movable electromagnet 4112 above to move downward, causing the annular valve 411 to move down, close the valve port, and make the annular valve 411 press the cover tightly again.

[0067] When the fixed electromagnet 4111 and the movable electromagnet 4112 are energized and their polarities repel each other, the magnetic force pushes the annular valve 411 upward, the reset spring 4113 is stretched, and the valve port is opened, allowing the chloride salt in the storage bin 41 to flow out.

[0068] See Figures 1 to 5 As shown, the lightweight heating furnace body 1 is provided with a breathable protective net 12 on its outer periphery, and an annular heat dissipation gap is left between the breathable protective net 12 and the outer surface of the lightweight heating furnace body 1.

[0069] During operation, the lightweight heating furnace body 1 generates a large amount of heat due to the continuous heating of the internal high-temperature furnace cavity, causing its outer surface temperature to rise. At this time, the annular heat dissipation gap allows air circulation, reducing the surface temperature of the lightweight heating furnace body 1.

[0070] Meanwhile, the breathable protective net 12 is woven from high-temperature resistant metal wire, which can prevent operators from accidentally touching the high-temperature furnace wall and causing burns, and can also block external debris or tools from falling into the heating area, thus taking into account both safety protection and passive heat dissipation functions.

[0071] A lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery method, applied to the aforementioned lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device, includes the following steps:

[0072] S1. Load the low-antimony crude lead into the high-temperature resistant crucible 2 and place it in the lightweight heating furnace body 1. Then close the furnace lid 3 and heat it to 900℃ to completely melt the lead.

[0073] S2. Air is blown in through the microporous gas distributor 51 and oxidized at 850–920℃ for 10–30 minutes to oxidize the residual antimony into antimony trioxide.

[0074] S3. Start the valve driver to open the annular valve 411, drive the uniform material plate 42 to rotate, and evenly spread the chloride salt material on the surface of the molten lead through the material tank 421. Heat to 950℃ and keep warm for 15–30 minutes to convert bismuth into bismuth trichloride and volatilize and remove it.

[0075] S4. After the reaction is completed, the lifting drive 6 raises the furnace cover 3, takes out the high-temperature resistant crucible 2, separates the upper layer of molten salt slag, pours the lower layer of silver-rich lead liquid, and recovers the high silver lead ingot.

[0076] This invention achieves efficient and safe separation of silver and bismuth in low-antimony crude lead by integrating a lightweight heating furnace body 1, a liftable furnace lid 3, and a material spreading and gas supply system. A high-temperature resistant crucible 2 is placed inside the high-temperature furnace chamber, with precise temperature control by a bottom temperature control platform 11. The furnace lid 3 opens and closes automatically, and the material spreading component 4 on it controls the quantitative release of chloride salts via an electromagnetically driven annular valve 411. The salts fall through a material drop channel 31 into a uniform material tray 42 with a sloping surface 422 and a radial material trough 421, where they are evenly spread on the surface of the molten lead under the influence of gravity and rotation.

[0077] Simultaneously, the high-temperature resistant gas tube 5 introduces air through the microporous gas distributor 51 to complete the initial oxidation, and the stirring bar 52 agitates the liquid surface at low speed to promote the reaction. The immersion depth is adjusted by raising and lowering the high-temperature resistant gas tube 5, and the slag removal ring 4232 automatically scrapes off surface residues when it rises. No manual intervention is required, ensuring uniform and efficient reaction, improving bismuth removal rate, silver enrichment purity, and operational safety.

[0078] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device, characterized in that, include: The lightweight heating furnace body has a high-temperature furnace chamber inside and a temperature control platform integrated at its bottom; A high-temperature resistant crucible is removably embedded in the high-temperature furnace cavity for holding crude lead and smelting it. A furnace lid covers the top of the high-temperature resistant crucible and can move up and down along the axial direction of the high-temperature resistant crucible; The material spreading assembly, installed on the furnace cover, includes a material storage bin and a material spreading tray located below it, for uniformly spreading solid chloride salts on the surface of molten lead; A high-temperature resistant gas pipe is coaxially installed in the center of the storage silo. Its upper end is connected to an external gas source, and its lower end passes through the furnace cover and is integrally connected to a microporous gas distributor for blowing reaction gas into the molten lead in the high-temperature crucible. The storage silo is fixed to the top of the furnace cover and has an annular valve coaxial with the high-temperature gas pipe; The material distribution plate is rotatably disposed at the bottom of the furnace cover and has material troughs evenly distributed along its circumference. The furnace cover is evenly provided with several material discharge channels along its circumference, which connect the material storage bin and the material distribution tray. The lightweight heating furnace body is equipped with a lifting drive on its side for moving the furnace cover.

2. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 1, characterized in that, The material troughs are opened radially along the material distribution plate. The upper surface of the material distribution plate is provided with inclined slopes that slope towards each material trough, which are used to guide the salt material to slide smoothly into the material troughs under the action of gravity and to spread evenly around the circumference as the material distribution plate rotates.

3. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 2, characterized in that, The uniform material tray has a bushing at its center that is fitted onto a high-temperature resistant gas pipe. The high-temperature resistant gas pipe has a stirring bar extending along its axial direction on its outer periphery. The bushing has an axial groove that mates with the stirring bar.

4. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 3, characterized in that, The high-temperature resistant gas pipe can move axially along the material distribution plate. A guide sleeve is provided on the furnace cover extending vertically upward and fitted onto the high-temperature resistant gas pipe. The upper end of the guide sleeve is provided with a rotary connecting pipe extending vertically downward and axially engaging with the high-temperature resistant gas pipe, which is used to transmit rotational power and allow axial relative displacement.

5. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 4, characterized in that, The upper end of the bushing is provided with a pivot ring that rotates with the furnace cover, and the lower end is provided with a slag-cleaning ring that fits tightly against the outer surface of the high-temperature gas pipe and the side of the stirring bar.

6. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 4, characterized in that, A guide cavity is formed between the guide sleeve and the rotary connecting pipe. The upper end of the high-temperature resistant gas pipe is provided with a piston embedded in the guide cavity. A compression spring is provided between the piston and the bottom of the guide cavity. The upper part of the guide sleeve is provided with a pressure inlet and a pressure release outlet that are respectively connected to the guide cavity.

7. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 1, characterized in that, The storage silo is an annular cavity with an open top. The annular valve inside is a conical valve structure with a sealing contact surface that can fit against the inner wall of the storage silo. The furnace cover is equipped with a valve actuator for driving the opening and closing of the annular valve.

8. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 7, characterized in that, The valve actuator includes a fixed electromagnet and a movable electromagnet located above it. The fixed electromagnet is fixedly connected to the furnace cover, and the movable electromagnet is fixedly connected to the annular valve. A return spring is fixedly connected between the fixed electromagnet and the movable electromagnet.

9. The lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device according to claim 1, characterized in that, The lightweight heating furnace body is provided with a breathable protective net around its outer periphery, and an annular heat dissipation gap is left between the breathable protective net and the outer surface of the lightweight heating furnace body.

10. A lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery method, applied to the lightweight, high-temperature resistant, low-antimony lead-silver-bismuth separation and recovery device described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Load the low-antimony crude lead into a high-temperature resistant crucible and place it in a lightweight heating furnace. Then close the furnace lid and heat it to 900°C to completely melt the lead. S2. Air is blown in through a microporous gas distributor and oxidized at 850–920℃ for 10–30 minutes to oxidize the residual antimony into antimony trioxide. S3. Start the valve actuator to open the annular valve, drive the uniform material plate to rotate, and evenly spread the chloride salt material on the surface of the molten lead through the material tank. Heat to 950℃ and keep it for 15–30 minutes to convert bismuth into bismuth trichloride and volatilize it. S4. After the reaction is complete, the lifting drive raises the furnace cover, removes the high-temperature resistant crucible, separates the upper layer of molten salt slag, pours the lower layer of silver-rich lead liquid, and recovers the high-silver lead ingot.

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