Zinc smelting system and process based on argon circulation and centralized zinc collection

Abstract

This invention discloses a zinc smelting furnace system and process based on argon circulation and centralized zinc collection. The invention relates to the field of non-ferrous metal metallurgical equipment technology. The heating unit provides the heat required for the smelting process. Two parallel smelting units are used, each containing a graphite container loaded with waste alloy and zinc raw materials, and serving as a reaction space. The zinc collection unit is fluidly connected to the smelting units and is used to collect the liquid zinc condensed from the zinc vapor distilled from the smelting units. A movable heating hood is used in conjunction with two fixed smelting chambers. The heating hood alternately heats the two furnace positions via an outer hood mover. This structure eliminates the need for specialized lifting equipment, reduces height requirements, and allows for a more compact layout. The heating hood retains its accumulated heat during transfer, reducing heat loss from repeated heating and facilitating continuous production.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal metallurgical equipment technology, specifically to a zinc furnace system and process based on argon circulation and centralized zinc collection. Background Technology

[0002] Zinc smelting is a mature recycling process for waste cemented carbide. Its basic principle is to utilize the dissolving effect of molten zinc on the cemented carbide binder phase (usually cobalt), and the high volatility of zinc at high temperatures, to dissolve the cobalt in the waste alloy, forming a zinc-cobalt alloy. Simultaneously, the tungsten carbide framework collapses and separates. Zinc is then removed by distillation, yielding recyclable tungsten carbide powder and recovered zinc. The core equipment for this process is the zinc smelting furnace.

[0003] Currently, most zinc smelting furnaces used in the industry adopt a single-unit structure, meaning one heating system corresponds to one smelting chamber. This structure has the following limitations in practical applications: First, the heating system of a traditional zinc furnace is usually fixed to the furnace body. When a batch of material has finished heating and entered the cooling stage, the heating system can only be idle and cannot be put into production for the next batch. This "one-to-one" working mode results in low overall equipment utilization, large heat loss, and difficulty in achieving continuous operation.

[0004] Secondly, in the design of the zinc collection process, existing equipment often uses a separate zinc discharge port for each graphite space to connect with the external zinc collection device. Due to thermal expansion and deformation of the graphite space and furnace body at high temperatures, it is difficult to maintain accurate alignment between the boat outlet and the zinc collection inlet, easily creating gaps. This causes zinc vapor to overflow and condense inside the equipment, forming "flying zinc." This flying zinc condenses on the furnace wall, pipe bends, and other parts, not only affecting the smooth flow of the zinc collection channel, causing zinc backflow or blockage, but also corroding furnace components and increasing equipment failure rate. To remove these flying zinc deposits, operators need to periodically stop the machine and enter the furnace for cleaning, resulting in a large workload and impacting production efficiency.

[0005] To address these technical problems, a zinc smelting furnace system and process based on argon gas circulation and centralized zinc collection were designed. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a zinc furnace system and process based on argon gas circulation and centralized zinc collection, which solves the technical problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a zinc smelting furnace system based on argon gas circulation and centralized zinc collection, comprising: Heating unit, the heating unit being used to provide the heat required for the melting process; Two parallel melting units, each of which is used to house a graphite container loaded with waste alloy and zinc raw material, and to serve as a reaction space; A zinc collecting unit, which is in fluid communication with the smelting unit, is used to collect liquid zinc condensed from zinc vapor distilled from the smelting unit. A gas circulation unit, which forms a circulation loop with the smelting unit, is used to introduce inert gas and drive it to circulate within the smelting unit to carry and recover residual zinc vapor.

[0008] In some embodiments, the heating unit includes a movable heating shroud configured to selectively cover either of the melting units to achieve alternating heating between the two melting units.

[0009] In some embodiments, a first outer cover mover and a second outer cover mover are also included to drive the heating cover to move automatically between the at least two smelting units, thereby realizing a one-to-two continuous working mode without the need for lifting equipment.

[0010] In some embodiments, the smelting unit includes a smelting chamber with a bottom heating zone for auxiliary heating of the bottom of the graphite space.

[0011] In some embodiments, the zinc collection unit includes a zinc collector having sufficient volume to contain liquid zinc produced by multiple smelting processes, and the bottom of the zinc collector is provided with a zinc discharge device for automatically or manually controlling the discharge of recovered zinc.

[0012] In some embodiments, the gas circulation unit includes a Roots blower, the inlet and outlet of which are connected to the melting chamber via pipes to form a closed loop for argon circulation.

[0013] In some embodiments, a heat exchanger is also connected in series in the gas circulation loop to cool the circulating gas, thereby improving the zinc collector's efficiency in capturing zinc vapor.

[0014] In some embodiments, a vacuum system is also included, comprising a vacuum pump and a Roots pump, connected to the smelting unit and the gas circulation unit via vacuum pipes, for evacuating the system during the initial smelting and zinc recovery stages.

[0015] In some embodiments, the system includes multiple temperature measuring points distributed at key locations in the heating hood and the smelting chamber, for real-time monitoring and control of the temperature at each stage of the smelting and zinc collection process.

[0016] A zinc smelting furnace process based on argon gas circulation and centralized zinc collection, employing the above system, includes the following steps; a. Loading steps: The waste alloy and zinc are loaded into the graphite space in a certain proportion, and the graphite space is placed in the melting chamber; b. Heating and melting step: The melting chamber is heated by the heating cover and the bottom heating zone to raise the temperature to the preset melting temperature and then hold it at that temperature; c. Main zinc collection step: Start the vacuum pump and Roots pump to evacuate the smelting chamber, so that zinc vapor evaporates from the graphite space and enters the zinc collector for condensation and collection through the smelting chamber outlet; d. Zinc recovery from tail gas: shut down the vacuum system, fill the smelting chamber with argon gas, and start the Roots blower to circulate the argon gas within the system, carrying the residual zinc vapor to the zinc collector for complete recovery; e. Zinc release step: The liquid zinc collected in the zinc collector is released through the zinc release device; f. Discharge procedure: Remove the heating cover and, after the melting chamber has cooled, remove the zinc molten material block from the graphite space.

[0017] This invention provides a zinc smelting furnace system and process based on argon circulation and centralized zinc collection, offering the following advantages: The invention employs a layout of a movable heating hood and two fixed smelting chambers. The heating hood alternately heats the two furnace positions via an outer hood mover. This structure eliminates the need for specialized lifting equipment, imposes no additional height requirements on the plant, and allows for a more compact layout. The heating hood retains its accumulated heat during transfer, reducing heat loss from repeated heating and facilitating continuous production. The invention also incorporates a process combining vacuum distillation and gas circulation. After conventional vacuum distillation, argon gas is circulated within the smelting chamber by a fan, carrying residual trace amounts of zinc vapor to the zinc collector for condensation. The zinc collector uses a centralized collection method, avoiding potential misalignment issues that might occur with individually designed zinc outlets in each graphite space. This process path improves zinc vapor capture efficiency and ensures more thorough recovery. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] In the diagram: 1. Heating hood; 2. Melting chamber; 3. Graphite space; 4. Roots blower; 5. Zinc collector; 6. Heat exchanger; 7. Melting chamber outlet; 8. Zinc collector and discharge device; 9. Temperature measuring point; 10. Bottom heating zone; 11. First outer cover mover; 12. Second outer cover mover; 13. Vacuum pump; 14. Roots pump; 15. Vacuum pipeline. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 This invention provides a zinc furnace system and process technology solution based on argon gas circulation and centralized zinc collection: A zinc furnace system based on argon gas circulation and centralized zinc collection includes: a heating unit for providing the heat required for the smelting process; two parallel smelting units, each smelting unit for accommodating a graphite container loaded with waste alloy and zinc raw materials, and serving as a reaction space; a zinc collection unit, which is fluidly connected to the smelting units, for centrally collecting liquid zinc condensed from zinc vapor distilled from the smelting units; and a gas circulation unit, which forms a circulation loop with the smelting units, for introducing inert gas and driving it to circulate within the smelting units to carry and recover residual zinc vapor.

[0022] In some embodiments, the heating unit includes a movable heating shroud 1 configured to selectively cover either melting unit to achieve alternating heating between the two melting units.

[0023] This portable design allows one heating unit to serve multiple smelting units, avoiding the heating system being idle during smelting intervals and significantly improving the overall utilization efficiency of the equipment.

[0024] In some embodiments, a first outer cover mover 11 and a second outer cover mover 12 are also included to drive the heating cover 1 to move automatically between at least two smelting units, thereby realizing a one-to-two continuous working mode without the need for lifting equipment.

[0025] The automatic transfer of the heating hood by the outer cover mover not only eliminates the need for lifting equipment and corresponding tall workshops required in traditional designs, reducing infrastructure investment, but also achieves seamless connection between the two furnaces, making the production process more continuous and smooth.

[0026] In some embodiments, the smelting unit includes a smelting chamber 2, and a bottom heating zone 10 is provided in the smelting chamber 2 for auxiliary heating of the bottom of the graphite space 3.

[0027] The bottom heating zone improves the uniformity of the temperature field inside the furnace, ensuring that the material in the graphite space is heated more fully and evenly, which is conducive to improving the quality and efficiency of the smelting reaction.

[0028] In some embodiments, the zinc collection unit includes a zinc collector 5 with sufficient volume to contain liquid zinc produced by multiple smelting processes, and a zinc collector discharge device 8 is provided at the bottom of the zinc collector 5 for automatic or manual control of the discharge of recovered zinc.

[0029] The centralized zinc collection design avoids the docking problems caused by setting up separate zinc discharge ports for each graphite space. Structurally, it eliminates the root cause of zinc vapor overflow and zinc fly condensation caused by poor docking. At the same time, the large-volume design allows the zinc discharge operation to be carried out on demand without discharging for each furnace, simplifying the operation process.

[0030] In some embodiments, the gas circulation unit includes a Roots blower 4, the inlet and outlet of which are connected to the melting chamber 2 via pipes, forming a closed loop for argon gas circulation.

[0031] By using a fan to drive inert gas to form a forced circulation, trace amounts of zinc vapor remaining in the dead corners of the chamber and on the inner walls of the pipes can be effectively purged and carried to the condensation area, thus making up for the deficiency of relying solely on vacuum distillation to capture low concentrations of residual zinc.

[0032] In some embodiments, a heat exchanger 6 is also connected in series in the gas circulation loop to cool the circulating gas, thereby improving the zinc collector 5's efficiency in capturing zinc vapor.

[0033] The heat exchanger actively cools the circulating airflow, allowing the zinc vapor to condense and precipitate more fully when it reaches the zinc collector, further reducing the zinc content in the exhaust gas and improving the recovery efficiency.

[0034] In some embodiments, a vacuum system is also included, comprising a vacuum pump 13 and a Roots pump 14, connected to the smelting unit and the gas circulation unit via a vacuum pipe 15, for evacuating the system during the initial smelting and zinc recovery stages.

[0035] The vacuum system and the gas circulation system work together to form a multi-stage zinc recovery process of "vacuum distillation first, followed by atmosphere purging". The two complement each other, making the zinc recovery process more thorough and reliable.

[0036] In some embodiments, the system includes multiple temperature measuring points 9, which are distributed at key locations in the heating hood 1 and the smelting chamber 2, for real-time monitoring and control of the temperature at each stage of the smelting and zinc collection process.

[0037] Multi-point temperature monitoring provides a data foundation for precise control of the process, helps maintain temperature stability at each stage, ensures consistent product quality, and creates conditions for automated operation.

[0038] A zinc smelting furnace process based on argon gas circulation and centralized zinc collection, employing the above system, includes the following steps; a. Loading steps: Load the waste alloy and zinc into the graphite space 3 in proportion, and place the graphite space 3 into the melting chamber 2; b. Heating and melting step: The melting chamber 2 is heated by the heating cover 1 and the bottom heating zone 10 to raise the temperature to the preset melting temperature and hold it at that temperature; c. Main zinc collection steps: Start vacuum pump 13 and Roots pump 14 to evacuate the melting chamber 2, so that zinc vapor evaporates from the graphite space 3 and enters the zinc collector 5 through the melting chamber outlet 7 for condensation and collection; d. Zinc recovery from tail gas: Close the vacuum system, fill the melting chamber 2 with argon gas, and start the Roots blower 4 to circulate the argon gas in the system, carrying the residual zinc vapor to the zinc collector 5 for complete recovery. e. Zinc release step: The liquid zinc collected in the zinc collector 5 is released through the zinc collector 8; f. Discharge procedure: Remove the heating cover 1, and after the melting chamber 2 has cooled, remove the zinc molten material block from the graphite space 3.

[0039] It is worth noting that all standard parts used in this invention can be purchased from the market, and irregularly shaped parts can be customized according to the description and drawings. The specific connection methods of each part all adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The models of electrical structure equipment involved can be selected according to the user's needs, as long as they meet the requirements of this application. In addition, the circuit connection adopts conventional connection methods in the prior art. The supporting electrical structures such as the control, current detection, position feedback, predicted voltage synchronization and parameter adjustment of the electrical equipment are all existing technologies, such as PLC controllers and module structures, so they will not be described in detail here.

[0040] A specific embodiment of this application is described below with reference to the accompanying drawings: Example 1: The system includes a movable heating shroud 1, which serves as the "heating unit" in the broader concept. Heating elements are arranged inside the heating shroud 1 to provide the heat required for the smelting process. The system also includes two parallel smelting chambers 2, which are also "smelting units" in the broader concept. The two smelting chambers 2 are fixedly installed and have identical structures, both used to house the graphite space 3 containing waste alloy and zinc raw materials, and serving as the space for the zinc melting reaction. This "one-to-two" design allows the heating shroud 1 to operate alternately between the two smelting chambers 2.

[0041] To enable the automatic movement of the heating hood 1, the system is equipped with a first outer hood mover 11 and a second outer hood mover 12. After the first melting chamber 2 completes melting and enters the cooling stage, the outer hood mover can drive the heating hood 1 to move automatically and cover the second melting chamber 2 to begin the next round of heating. This process requires no lifting equipment or manual intervention, achieving continuous production.

[0042] The system includes a zinc collector 5, referred to as the "zinc collection unit" in the higher-level concept. This collector 5 has a large volume, capable of holding up to 1500 kg of recovered zinc, and is connected via pipes to the smelting chamber outlets 7 of the two smelting chambers 2. This centralized collection method avoids individual connection of each graphite space 3 to the zinc discharge port, eliminating zinc spillage caused by poor connection, protecting the equipment, and ensuring stable zinc content. At the bottom of the collector 5 is a zinc collection and dispensing device 8, which can be automatically or manually controlled by the operator to precisely release the collected liquid zinc into a receiving container, ensuring consistent weight for each batch of recovered zinc.

[0043] The system constructs an argon gas circulation loop, namely the "gas circulation unit" in the higher-level concept. The core of this loop is a Roots blower 4, whose inlet and outlet are connected to the internal space of the smelting chamber 2 via sealed pipes. In the later stages of zinc recovery, the system introduces argon gas into the smelting chamber 2, starts the Roots blower 4, and drives the argon gas to flow at high speed within the smelting chamber 2 and the pipes, carrying the residual trace amounts of zinc vapor to the zinc collector 5 for condensation. To further improve condensation efficiency, a set of heat exchangers 6 is connected in series in the circulation loop to cool the circulating gas and enhance the zinc vapor capture capability.

[0044] The system is also equipped with a complete vacuum system, including a vacuum pump 13 and a Roots pump 14. They are connected to the melting chamber 2 and the argon circulation loop via vacuum pipe 15. In the initial melting stage and the main zinc collection stage, the vacuum system is responsible for evacuating the furnace to a high vacuum state to promote the rapid volatilization and distillation of zinc.

[0045] To ensure precise control of the process, the system has arranged multiple temperature measuring points 9 at key locations in the heating hood 1 and melting chamber 2 to monitor and feed back temperature signals to the central control system in real time.

[0046] Example 2: Zinc melting process using the above system This embodiment describes the complete process of processing waste cemented carbide using the system described in Embodiment 1.

[0047] Step a: Loading step. The waste alloy and zinc are loaded into the graphite space 3 in proportion, and the graphite space 3 is placed into the melting chamber 2. The furnace door is then closed and locked.

[0048] Step b: The heating and melting step involves heating the melting chamber 2 using the heating cover 1 to raise the temperature of the melting chamber 2 to the preset melting temperature and maintaining this temperature. During this process, the bottom heating zone 10 located at the bottom of the melting chamber 2 provides auxiliary heating to the graphite space 3 to improve the uniformity of the temperature field inside the furnace. Temperature measuring points 9 monitor the temperature of each part in real time and feed it back to the control system.

[0049] Step c: In the main zinc collection step, the vacuum pump 13 and the Roots pump 14 are started to evacuate the smelting chamber 2, causing zinc vapor to evaporate from the graphite space 3 and enter the zinc collector 5 through the smelting chamber outlet 7 for condensation and collection. The zinc collector 5, with its large volume, can accommodate the liquid zinc generated in multiple smelting processes, achieving centralized collection.

[0050] Step d: Zinc recovery from tail gas. The vacuum system is shut off, argon gas is introduced into the smelting chamber 2, and the Roots blower 4 is started to circulate the argon gas within the system, carrying the remaining zinc vapor to the zinc collector 5 for complete recovery. During this process, the circulating gas flow is cooled by the heat exchanger 6 to improve the zinc collector 5's efficiency in capturing zinc vapor.

[0051] Step e: Zinc release step. The liquid zinc collected in the zinc collector 5 is released through the zinc collector 8. The zinc release operation can be controlled automatically or manually according to the production rhythm.

[0052] Step f: Remove the heating cover 1 and, after the melting chamber 2 has cooled, remove the zinc molten material block from the graphite space 3.

[0053] In the above process, after the first melting chamber 2 completes melting and enters the cooling stage, the first outer cover mover 11 and the second outer cover mover 12 drive the heating cover 1 to automatically move to the second melting chamber 2 to start the next round of heating, realizing a one-to-two continuous working mode without the need for lifting equipment.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A zinc smelting furnace system based on argon gas circulation and centralized zinc collection, characterized in that, include: Two parallel melting units, each of which is used to house a graphite container loaded with waste alloy and zinc raw material, and to serve as a reaction space; A heating unit, wherein the heating unit is used to heat the melting unit; A zinc collecting unit, which is in fluid communication with the smelting unit, is used to collect liquid zinc condensed from zinc vapor distilled from the smelting unit. A gas circulation unit, which forms a circulation loop with the smelting unit, is used to introduce inert gas and drive it to circulate within the smelting unit to carry and recover residual zinc vapor.

2. The zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 1, characterized in that, The heating unit includes a movable heating shroud (1) configured to selectively cover either of the smelting units to achieve alternating heating between the two smelting units.

3. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 2, characterized in that, It also includes a first outer cover mover (11) and a second outer cover mover (12), the first outer cover mover (11) being used to drive the heating cover (1) to move toward one smelting unit, and the second outer cover mover (12) being used to drive the heating cover (1) to move toward another smelting unit.

4. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 1, characterized in that, The melting unit has a melting chamber (2) and a bottom heating zone (10) is provided in the melting chamber (2) for auxiliary heating of the bottom of the graphite space (3).

5. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 1, characterized in that, The zinc collection unit includes a zinc collector (5), which has a container for liquid zinc produced during the smelting process, and a zinc collection and discharging device (8) is provided at the bottom of the zinc collector (5).

6. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 1, characterized in that, The gas circulation unit includes a Roots blower (4), the inlet and outlet of which are connected to the melting chamber (2) via pipes to form a closed loop for argon circulation.

7. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 6, characterized in that, A heat exchanger (6) is also connected in series in the gas circulation loop to cool the circulating gas, thereby improving the zinc collector (5)’s efficiency in capturing zinc vapor.

8. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 1, characterized in that, It also includes a vacuum system, which includes a vacuum pump (13) and a Roots pump (14), connected to the smelting unit and the gas circulation unit via a vacuum pipe (15), for evacuating the zinc furnace system during the initial smelting and zinc collection stages.

9. A zinc smelting furnace system based on argon circulation and centralized zinc collection according to claim 1, characterized in that, The zinc furnace system includes multiple temperature measuring points (9), which are distributed on the heating hood (1) and the smelting chamber (2) to monitor and control the temperature at each stage of the smelting and zinc collection process in real time.

10. A zinc smelting furnace process based on argon gas circulation and centralized zinc collection, applied to the zinc smelting furnace system based on argon gas circulation and centralized zinc collection as described in any one of claims 1 to 9, characterized in that, The zinc smelting furnace process based on argon circulation and centralized zinc collection includes the following steps: a. Loading steps: Load the waste alloy and zinc into a graphite container in a certain proportion, and place the graphite container into the smelting unit; b. Heating and melting step: The melting unit is heated by the heating unit to raise the temperature to the preset melting temperature and then held at that temperature; c. Main zinc collection step: The smelting unit is evacuated to allow zinc vapor to evaporate from the graphite container and enter the zinc collection unit for condensation and collection via a fluid communication path; d. Zinc recovery from tail gas: Close the vacuum, fill the smelting unit with inert gas, and drive the inert gas to flow in the circulation loop through the gas circulation unit to carry the residual zinc vapor to the zinc collection unit for recovery; e. Zinc release step: Release the liquid zinc collected in the zinc collection unit; f. Discharge procedure: Remove the heating unit and, after the melting unit has cooled down, remove the zinc molten material block from the graphite container.

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