A preparation system of silicon-thermal magnesium smelting sintering material ball

Abstract

The present application belongs to the technical field of magnesium smelting, and discloses a preparation system of sintered material balls for magnesium smelting by silicon-heat method, which comprises a raw material ball bin, a closed belt conveyor is sealingly connected to a discharge port at the bottom of the raw material ball bin, the closed belt conveyor is connected with a high-temperature sintering furnace, magnesium smelting material balls are calcined in the high-temperature sintering furnace to form sintered material balls, a discharge port of the high-temperature sintering furnace is connected with a high-temperature vibrating screen, qualified sintered material balls after passing through the high-temperature vibrating screen are fed into a sintered material ball buffer bin, and the sintered material ball buffer bin is provided with a high-temperature scale plate conveyor for being connected with a magnesium reduction tank; undersize material of the sintered material balls after passing through the high-temperature vibrating screen is returned to a ball making process through a discharging and recycling system for preparation of magnesium smelting material balls; the problems of low strength, easy moisture absorption and easy pulverization of the material balls are solved, no dust is overflowed in the whole process of conveying and feeding, the problem of "tank sticking and glaze forming" of the reduction tank caused by powder feeding into the tank is eliminated from the root, the service life of the reduction tank is prolonged, and the recovery rate of magnesium metal is improved.

Description

Technical Field

[0001] This invention belongs to the field of magnesium smelting technology, and specifically relates to a system for preparing magnesium sintering pellets by the silicothermic process. Background Technology

[0002] The silicothermic process for magnesium smelting has become the mainstream technology in the global magnesium smelting field due to its advantages such as wide availability of raw materials, mature technology, and relatively controllable production costs. It accounts for over 90% of the total magnesium smelting capacity, and the produced magnesium has irreplaceable strategic application value in aerospace, automotive manufacturing, and the electronics industry. The core process of the silicothermic process is as follows: calcined dolomite, ferrosilicon powder, fluorite powder, and other raw materials are mixed evenly according to the process ratio, then pressed into briquettes of specific shape and strength using a briquetting machine. These briquettes are then fed into a reduction tank, where a reduction reaction is completed under high temperature and vacuum conditions, ultimately producing primary magnesium.

[0003] As the core reaction medium in the silicothermic magnesium smelting process, the mechanical strength, density, and water resistance of the pellets directly determine the sufficiency of the reduction reaction, the yield of metallic magnesium, and the purity of the product. These are key factors affecting the overall production efficiency and economic benefits of the magnesium smelting process. However, the traditional silicothermic magnesium smelting process currently in the industry suffers from rudimentary processes and incomplete supporting systems in the front-end pellet processing stage, becoming a core bottleneck restricting the upgrading of the silicothermic magnesium smelting industry towards higher efficiency, greener practices, and larger-scale production.

[0004] Specifically, in existing traditional pellet preparation processes, after the raw materials are pressed by a pelletizing machine, they are directly fed into the reduction tank for high-temperature reduction via manual transfer or simple conveying equipment, or only undergo simple sieving before filling. The powder and unqualified pellets produced by sieving are directly discarded. The entire front-end pellet processing lacks professional and systematic enhancement and recycling processes. This extensive production model makes the pellets highly susceptible to moisture absorption and pulverization during transportation and feeding. A large amount of powder entering the reduction tank causes problems such as tank sticking and glazing, which not only shortens the service life of the reduction tank and reduces the effective feeding amount per tank, but also makes it difficult to discharge slag from the vertical tank, directly reducing the output of metallic magnesium and significantly increasing the overall production cost. At the same time, the direct disposal of undersize material results in serious waste of raw materials, further increasing production costs, which contradicts the concept of green production. Summary of the Invention

[0005] The purpose of this invention is to address the problems in traditional, extensive pellet preparation processes, such as pellets easily absorbing moisture and pulverizing during transportation and feeding, leading to problems like pellet sticking and glazing in the reduction tank after a large amount of powder enters the tank, and the direct waste of undersize material resulting in serious raw material waste. This invention proposes a pellet preparation system for magnesium sintering via a silicothermic process. The technical solution adopted to achieve the above objectives is as follows: A system for preparing magnesium sintering pellets using the silicothermic process includes a raw material pellet silo for storing magnesium sintering pellets. A sealed belt conveyor is connected to the bottom outlet of the raw material pellet silo. The sealed belt conveyor is connected to a high-temperature sintering furnace. The magnesium sintering pellets are calcined in the high-temperature sintering furnace to form sintering pellets. The outlet of the high-temperature sintering furnace is connected to a high-temperature vibrating screen. After passing through the high-temperature vibrating screen, qualified sintering pellets enter a sintering pellet buffer silo. The sintering pellet buffer silo is equipped with a high-temperature alumina plate conveyor for connection to a magnesium reduction tank. The undersize material after passing through the high-temperature vibrating screen is returned to the pelletizing process for the preparation of magnesium sintering pellets via a waste recovery system.

[0006] Preferably, it also includes a material tray transfer system for circulating and transferring material trays, the material tray transfer system including a front powered roller conveyor, a pusher robotic arm, a high-temperature resistant roller conveyor, a rear powered roller conveyor, a puller robotic arm, an unloading mechanism, a bidirectional lifting transfer machine, and a rotary powered roller conveyor connected in sequence. The front powered roller conveyor and the pusher robotic arm are located at the ball inlet of the high-temperature sintering furnace, and the high-temperature resistant roller conveyor is located inside the high-temperature sintering furnace. The rear powered roller conveyor, the puller robotic arm, and the unloading mechanism are located at the ball outlet of the high-temperature sintering furnace. The rear powered roller conveyor is connected to the rotary powered roller conveyor through a bidirectional lifting and transfer machine. Finally, the rotary powered roller conveyor is connected to the front powered roller conveyor, thereby completing the cycle of receiving material from the closed belt conveyor, entering the high-temperature sintering furnace, transporting it out of the high-temperature sintering furnace, and returning to the front powered roller conveyor for the next receiving cycle.

[0007] Preferably, the high-temperature sintering furnace is a horizontal high-temperature sintering furnace and is equipped with a vacuum control system. The side of the horizontal high-temperature sintering furnace has a vacuum interface that is sealed and connected to the vacuum control system. The vacuum control system consists of a variable frequency vacuum pump, a pressure sensor, and a PLC linkage module. It can collect pressure data inside the horizontal high-temperature sintering furnace in real time and automatically adjust the frequency of the vacuum pump to maintain stable vacuum sintering conditions inside the horizontal high-temperature sintering furnace.

[0008] Preferably, the material recovery system includes a scraper conveyor installed at the bottom of the high-temperature vibrating screen. The scraper conveyor is connected to the mixing silo of the pelletizing workshop through a first bucket elevator mechanism. The mixing silo of the pelletizing workshop is used to supply materials for the pelletizing process. The pelletizing process stores the finished magnesium smelting pellets in the raw material pellet silo for later use.

[0009] Preferably, the high-temperature vibrating screen is connected to the sintering pellet buffer silo via a second bucket lifting mechanism. Both the enclosed belt conveyor and the sintering pellet buffer silo have built-in weighing functions. The high-temperature alumina plate conveyor is made of high-strength heat-resistant alloy steel plate and equipped with a constant temperature insulation structure.

[0010] Preferably, the high-temperature sintering furnace is a vacuum resistance sintering furnace, an atmosphere resistance sintering furnace, or a dual-purpose vacuum and atmosphere resistance sintering furnace. A vacuum resistance sintering furnace has a vacuum interface on the side of the furnace body, and a vacuum control system is sealed and connected to the vacuum interface. An atmosphere resistance sintering furnace is a furnace in which inert gas is introduced into the furnace body through an interface set on the furnace body to create a slight positive pressure inside the furnace, that is, the inert gas is in a state of flow consumption, and the gas flow rate is adjusted by detecting the pressure inside the furnace. The dual-purpose vacuum and atmosphere resistance sintering furnace is a combination of a vacuum resistance sintering furnace and an atmosphere resistance sintering furnace. The furnace body is equipped with interfaces for a vacuum system and an inert gas system, and the control system can freely switch between the two furnace types.

[0011] Preferably, the high-temperature sintering furnace adopts two high-temperature sintering furnaces arranged in parallel, with the two high-temperature sintering furnaces working independently, and the two high-temperature sintering furnaces having flexible switching between dual working conditions and redundancy backup.

[0012] Preferably, the two high-temperature sintering furnaces can be any two of the following combinations: a vacuum resistance sintering furnace, an atmosphere resistance sintering furnace, or a vacuum-atmosphere dual-purpose resistance sintering furnace.

[0013] The beneficial effects of this invention are as follows: (1) Introducing a “high-temperature sintering strengthening process” into the silicothermic magnesium smelting process breaks through the traditional industry practice of “no sintering”. During the high-temperature sintering process, the elemental Si and FeSi2 in the ferrosilicon in the pellets react with CaO in the calcined white metal to generate stable silicon-calcium compounds. These compounds can encapsulate the easily absorbing MgO and CaO. At the same time, sintering significantly reduces the porosity inside the magnesium smelting pellets. The dual effect greatly improves the water resistance of the magnesium smelting pellets. Moreover, the generated silicon-calcium compounds have high adhesion and strength, which can effectively improve the overall mechanical strength of the pellets. This solves the problems of low pellet strength, easy moisture absorption, and easy pulverization. It achieves no powder generation during the entire process of conveying and feeding the pellets, eliminates the problem of “sticking to the tank and glazing” caused by powder entering the tank from the root, extends the service life of the reduction tank, and improves the yield of metallic magnesium.

[0014] (2) Add a material recovery system to return the powder and small particles separated by the high temperature vibrating screen directly to the pelletizing process through a special sealed scraper conveyor 14, so as to realize the recycling of raw materials and solve the problem of "direct waste disposal" in the existing process.

[0015] (3) By using dual quantitative feeding of magnesium smelting pellets before sintering and sintering pellets entering the magnesium reduction tank, quantitative transfer of magnesium smelting pellets before entering the furnace is achieved by weighing closed belt conveyor, and precise quantity control of sintering pellets before entering the magnesium reduction tank is achieved by using a secondary weighing sintering pellet buffer silo, thus solving the problems of rough quantitative feeding and large fluctuations in material quantity in traditional processes.

[0016] (4) Stabilize the reaction conditions inside the magnesium reduction tank, ensure the consistency of reduction efficiency in a single tank, significantly improve the overall yield of metallic magnesium and the stability of product quality, and enhance production economic benefits. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is one of the structural schematic diagrams of a material tray transfer system; Figure 3 This is the second schematic diagram of the material tray transfer system. Detailed Implementation

[0018] The present invention will now be further described with reference to the accompanying drawings. Specific Implementation Example 1 like Figure 1 and Figure 2 As shown, a system for preparing magnesium sintering pellets using the silicothermic process includes a raw material pellet silo 1 for storing magnesium sintering pellets. A sealed belt conveyor 2 is connected to the bottom outlet of the raw material pellet silo 1. The sealed belt conveyor 2 is connected to a high-temperature sintering furnace 5. The magnesium sintering pellets are calcined in the high-temperature sintering furnace 5 to form sintering pellets. The outlet of the high-temperature sintering furnace 5 is connected to a high-temperature vibrating screen 9. After passing through the high-temperature vibrating screen 9, qualified sintering pellets enter a sintering pellet buffer silo 11. The sintering pellet buffer silo 11 is equipped with a high-temperature alumina conveyor 12 for connection to a magnesium reduction tank. The undersize material after passing through the high-temperature vibrating screen 9 is returned to the pelletizing process 17 via a waste material recovery system for the preparation of magnesium sintering pellets.

[0020] Furthermore, this embodiment also includes a material tray transfer system for cyclically transferring the material tray 3. The material tray transfer system includes a front powered roller conveyor 4, a pusher robotic arm 25, a high-strength roller conveyor 6, a rear powered roller conveyor 7, a puller robotic arm 26, an unloading mechanism, a bidirectional lifting and transferring machine 8, and a rotary powered roller conveyor 18, which are connected in sequence from end to end. The front power roller conveyor 4 and the pusher robotic arm 25 are located at the ball inlet of the high-temperature sintering furnace 5. The high-temperature resistant roller conveyor 6 is located inside the high-temperature sintering furnace 5. The rear power roller conveyor 7, the puller robotic arm 26, and the unloading mechanism are located at the ball outlet of the high-temperature sintering furnace 5. The rear power roller conveyor 7 is connected to the rotary power roller conveyor 18 through the bidirectional lifting and transfer machine 8. Finally, the rotary power roller conveyor 18 is connected to the front power roller conveyor 4, thereby completing the cycle of the ball tray 3 receiving material from the closed belt conveyor 2, entering the high-temperature sintering furnace 5, exiting the high-temperature sintering furnace 5, and returning to the front power roller conveyor 4 for the next receiving operation.

[0021] The material recovery system includes a sealed scraper conveyor 14 installed at the bottom of the high-temperature vibrating screen 9. The scraper conveyor 14 is connected to the mixing silo 16 of the pelletizing workshop through the first bucket lifting mechanism 15. The mixing silo 16 of the pelletizing workshop is used to supply materials for the pelletizing process 17. The pelletizing process 17 stores the finished magnesium smelting pellets in the raw material pellet silo 1 for later use.

[0022] After passing through the high-temperature vibrating screen 9, the qualified sintered pellets are connected to the sintered pellet buffer bin 11 via the second bucket lifting mechanism 10. Both the sealed belt conveyor 2 and the sintered pellet buffer bin 11 have their own weighing function. The high-temperature alumina plate conveyor 12 is made of high-strength heat-resistant alloy steel plate and is equipped with a constant temperature insulation structure.

[0023] In operation, the high-temperature sintering furnace 5 in this embodiment is a horizontal vacuum resistance sintering furnace. The sintering parameters of the high-temperature sintering furnace 5 are retrieved, and according to actual needs, a certain mass of magnesia pellets are output via a sealed belt conveyor 2 with built-in weighing function. The magnesia pellets fall into a material tray 3. The front-powered roller conveyor 4 transports the material tray 3 containing the magnesia pellets to the front of the high-temperature sintering furnace 5, where a pushing robotic arm 25 pushes it onto the high-temperature resistant roller conveyor 6 inside the furnace. The high-temperature sintering furnace 5 is then started, and the magnesia pellets... Sintered pellets are formed by calcination in the high-temperature sintering furnace 5. Then, under the action of the puller arm 26, they are transported to the rear power roller conveyor 7. The unloading mechanism then pours the sintered pellets in the tray 3 into the high-temperature vibrating screen 9 for screening. After the tray 3 returns to the horizontal position, the bidirectional lifting transfer machine 8 transfers the tray 3 to the rotary power roller conveyor 18. The rotary power roller conveyor 18 finally rotates and transports the tray 3 to the front power roller conveyor 4 to wait for the next feeding, thus completing one cycle.

[0024] After passing through the high-temperature vibrating screen 9, qualified sintered pellets are fed into the sintered pellet buffer silo 11 via the second bucket elevator 10. Based on the required sintered pellet mass in the magnesium reduction tank, the buffer silo 11, with its built-in weighing function, transfers the required weight of sintered pellets into the magnesium reduction tank through the outlet 13 of the high-temperature abrasive plate conveyor 12. Alternatively, the undersize material from the high-temperature vibrating screen 9 falls onto the submerged scraper conveyor 14, which then conveys it to the pelletizing workshop mixing silo 16 via the first bucket elevator mechanism 15. The mixing silo 16 then supplies the material for the pelletizing process 17, which stores the finished magnesium smelting pellets in the raw material pellet silo 1 for use in the next sintering cycle. Specific Implementation Example 2 The high-temperature sintering furnace 5 in this embodiment can also be a horizontal atmosphere resistance sintering furnace. The main difference from specific embodiment 1 lies in the structure of the material tray transfer system; for example, its structure can also adopt... Figure 3The structure shown replaces the arc-shaped rotary power roller conveyor 18 with a structure consisting of four bidirectional lifting and transferring machines 8, 23, 21, 19 and three linear power roller conveyors 24, 22, 20, which can also achieve the cyclic operation of the material tray 3.

[0026] This embodiment targets silicothermic pellets, employing a horizontal atmosphere resistance sintering furnace. High-temperature strengthening of the pellets is achieved through an inert gas-protected sintering process. The sintered pellets meet all production standards, exhibiting no pulverization or breakage issues, and maintaining stable magnesium yield and product quality. Compared to vacuum sintering, this embodiment eliminates the need for costly vacuum pump units, vacuum sealing pressure regulation, and other precision components, resulting in lower initial equipment investment and subsequent maintenance costs. The furnace structure is compact, requiring minimal floor space, and adaptable to various production site layouts. It can precisely match diverse production rhythms, with no waste after closed-loop raw material recycling, offering high production flexibility. The equipment operates stably and is highly practical, fully demonstrating the adaptability of this invention. Specific Implementation Example 3 In this embodiment, the high-temperature sintering furnace 5 is a horizontal dual-purpose resistance sintering furnace with vacuum atmosphere. This embodiment allows for flexible switching between two processes and adaptability to various production needs. Addressing the intermittent operation characteristics of the single-tank reduction vessel in the silicothermic process, the horizontal dual-purpose resistance sintering furnace enables on-demand switching between vacuum sintering and inert gas protected sintering processes, adapting to the unified requirements for pellet sintering without altering the original core reduction production line. The two processes can be flexibly selected and easily switched, precisely matching the reduction process and effectively solving the problems of poor adaptability and inflexible scheduling in the sintering process. The quality of the sintered pellets is stable, and the equipment has extremely high versatility and production flexibility. While ensuring production efficiency, it achieves the dual goals of energy saving and consumption reduction, as well as stable basic production. It is adaptable to magnesium smelting production lines of various production scales and rhythms, further highlighting the flexibility and practicality of this invention. Specific Implementation Example 4 In this embodiment, the high-temperature sintering furnace 5 adopts two high-temperature sintering furnaces connected in parallel. The two high-temperature sintering furnaces work independently of each other. The two high-temperature sintering furnaces have flexible switching between dual working conditions and redundancy backup. The two high-temperature sintering furnaces can be any two of the following combinations: vacuum resistance sintering furnace, atmosphere resistance sintering furnace, or vacuum atmosphere dual-purpose resistance sintering furnace.

[0029] Two high-temperature sintering furnaces are deployed in parallel and operate independently, achieving true hardware-level redundancy and completely overcoming the core challenges of easy downtime due to single-set sintering equipment failure and insufficient reliability of single-furnace dual-system in silicothermic magnesium smelting production lines. This fully meets the requirements of pellet sintering. The two sets of equipment operate independently and seamlessly, with efficient and reliable emergency switching without downtime, ensuring continuous sintering while significantly reducing economic losses from downtime. At the same time, they have core advantages such as high-temperature sintering enhancement, closed-loop raw material recovery, and precise quantitative separation. The equipment is highly versatile and easy to maintain, greatly improving the reliability of the production line and the utilization rate of equipment. It meets the needs of high-standard, stable industrial-scale production and further highlights the redundancy guarantee capability.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for preparing magnesium sintering pellets using the silicothermic process, characterized in that, The system includes a raw material silo for storing magnesium smelting pellets. A sealed belt conveyor is connected to the bottom outlet of the silo, and the belt conveyor is connected to a high-temperature sintering furnace. The magnesium smelting pellets are calcined in the furnace to form sintered pellets. The outlet of the furnace is connected to a high-temperature vibrating screen. Qualified sintered pellets after passing through the vibrating screen enter a sintered pellet buffer silo. This buffer silo is equipped with a high-temperature alumina conveyor for connection to a magnesium reduction tank. The undersize material from the vibrating screen is returned to the pelletizing process via a waste recovery system for the preparation of magnesium smelting pellets. It also includes a material tray transfer system for the cyclic transfer of material trays, the material tray transfer system comprising a front powered roller conveyor, a pusher robotic arm, a high-temperature resistant roller conveyor, a rear powered roller conveyor, a puller robotic arm, an unloading mechanism, a bidirectional lifting transfer machine, and a rotary powered roller conveyor connected in sequence from end to end; The front powered roller conveyor and the pusher robotic arm are located at the ball inlet of the high-temperature sintering furnace, and the high-temperature resistant roller conveyor is located inside the high-temperature sintering furnace. The rear powered roller conveyor, the puller robotic arm, and the unloading mechanism are located at the ball outlet of the high-temperature sintering furnace. The rear powered roller conveyor is connected to the rotary powered roller conveyor through a bidirectional lifting and transfer machine. Finally, the rotary powered roller conveyor is connected to the front powered roller conveyor, thereby completing the cycle of receiving material from the closed belt conveyor, entering the high-temperature sintering furnace, transporting it out of the high-temperature sintering furnace, and returning to the front powered roller conveyor for the next receiving cycle. The high-temperature sintering furnace is a horizontal high-temperature sintering furnace and is equipped with a vacuum control system. The side of the horizontal high-temperature sintering furnace has a vacuum interface that is sealed and connected to the vacuum control system. The vacuum control system consists of a variable frequency vacuum pump, a pressure sensor, and a PLC linkage module. It can collect pressure data inside the horizontal high-temperature sintering furnace in real time and automatically adjust the frequency of the vacuum pump to maintain the stability of the vacuum sintering conditions inside the horizontal high-temperature sintering furnace. The material recovery system includes a scraper conveyor installed at the bottom of the high-temperature vibrating screen. The scraper conveyor is connected to the mixing silo of the pelletizing workshop through a first bucket elevator mechanism. The mixing silo of the pelletizing workshop is used to supply materials for the pelletizing process. The pelletizing process stores the finished magnesium smelting pellets in the raw material pellet silo for later use. The high-temperature vibrating screen is connected to the sintering ball buffer silo via a second bucket lifting mechanism. Both the enclosed belt conveyor and the sintering ball buffer silo have built-in weighing functions. The high-temperature alumina plate conveyor is made of high-strength heat-resistant alloy steel plate and equipped with a constant temperature insulation structure.

2. The system for preparing magnesium sintering pellets by the silicothermic process according to claim 1, characterized in that, The high-temperature sintering furnace is a vacuum resistance sintering furnace, an atmosphere resistance sintering furnace, or a dual-purpose vacuum and atmosphere resistance sintering furnace. A vacuum resistance sintering furnace has a vacuum interface on the side of the furnace body, and a vacuum control system is sealed and connected to the vacuum interface. An atmosphere resistance sintering furnace is a furnace in which inert gas is introduced into the furnace body through an interface set on the furnace body to create a slight positive pressure inside the furnace, that is, the inert gas is in a state of flow consumption, and the gas flow rate is adjusted by detecting the pressure inside the furnace. The dual-purpose vacuum and atmosphere resistance sintering furnace is a combination of a vacuum resistance sintering furnace and an atmosphere resistance sintering furnace. The furnace body is equipped with interfaces for a vacuum system and an inert gas system, and the control system can freely switch between the two furnace types.

3. The system for preparing magnesium sintering pellets by the silicothermic process according to claim 1 or 2, characterized in that, The high-temperature sintering furnace consists of two high-temperature sintering furnaces connected in parallel. The two high-temperature sintering furnaces operate independently of each other and can achieve flexible switching between dual operating conditions and redundant backup.

4. The system for preparing magnesium sintering pellets by the silicothermic process according to claim 3, characterized in that, The two high-temperature sintering furnaces can be any two of the following: a vacuum resistance sintering furnace, an atmosphere resistance sintering furnace, or a vacuum-atmosphere dual-purpose resistance sintering furnace.

Images