Magnesium metal production line
By designing a metal magnesium production line, using two-stage fluidized bed drying and HCl exhaust gas recycling, the problems of high energy consumption and long process flow of anhydrous magnesium chloride were solved, and a low-energy consumption and low-pollution magnesium smelting process was realized, which improved the magnesium smelting process with low energy consumption and low pollution. Magnesium smelting efficiency and environmental protection.
Patent Information
- Application Number
- CN202421433121.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-06-21
AI Technical Summary
In the existing metal magnesium smelting process, electrolytic preparation of anhydrous magnesium chloride has high energy consumption, long process flow and high pollution. Especially the thermal reduction method (Pijiang method) has large resource and energy consumption, high waste emissions and high carbon emissions. The problem.
A metal magnesium production line was designed, including a magnesium ore dissolution separation device, a high-concentration magnesium chloride solution preparation device, a two-stage fluidized bed drying device and a magnesium electrolytic device. The two-stage fluidized bed drying device was used to dehydrate magnesium chloride, combined with HCl exhaust gas Recycling and hydrochloric acid preparation systems reduce energy consumption and waste emissions.
The energy consumption and waste emissions of electrolytic magnesium systems have been reduced, the process flow has been shortened, the preparation efficiency of anhydrous magnesium chloride has been improved, and environmental pollution has been reduced through recycling.
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Figure CN222226492U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of metal magnesium industrial production, in particular to a metal magnesium production line. Background Art
[0002] Magnesium has the characteristics of high strength, low density, large elastic modulus, good heat dissipation, good shock absorption, greater impact load bearing capacity than aluminum alloy, and good resistance to corrosion from organic matter and alkali. It can meet the requirements of weight reduction and energy conservation in the fields of aviation, aerospace, modern automobiles, rail transit, ships, national defense and military industry. It is recognized by the world as the third largest metal structural material after steel and aluminum, and is known as the green engineering material of the 21st century.
[0003] Magnesium resources can be divided into solid ores and liquid ores. Solid ores refer to various non-metallic minerals containing magnesium, such as magnesite, dolomite, brucite, natural brine blocks, etc. Liquid ores refer to magnesium-containing brine resources, such as seawater, salt lake brine, underground brine and well brine. At present, there are two main methods for smelting magnesium metal. One is electrolysis, which is to melt anhydrous magnesium chloride and electrolyze it to obtain metallic magnesium; the other is thermal reduction, also known as Pijiang method, which uses solid ore as raw material and uses ferrosilicon and other reducing agents to thermally reduce magnesium oxide produced by calcination from ore to obtain metallic magnesium. Pijiang method magnesium refining needs to be carried out under high temperature and vacuum conditions. The production process consumes relatively large resources and energy, and the waste discharge is large, the carbon emission is high, and the ecological environment protection risk is high. Therefore, it is an inevitable trend that Pijiang method magnesium refining will be eliminated by the market. The principle of electrolytic magnesium refining is to electrolyze molten anhydrous magnesium chloride at high temperature to decompose it into metallic magnesium and chlorine. The influence of water on the properties of molten salt under high temperature is fatal. Therefore, the preparation of anhydrous magnesium chloride is a key link in electrolytic magnesium refining.
[0004] At present, the preparation technologies of anhydrous magnesium chloride mainly include ammonia complex dehydration method, melt chlorination dehydration method, and dehydration method under hydrogen chloride protective atmosphere. However, the existing preparation processes of anhydrous magnesium chloride have certain shortcomings:
[0005] The ammonia complex dehydration method is still in the research stage and has no industrial application;
[0006] The melt chlorination dehydration method is to place MgCl2 powder (containing MgO and H2O) in a chlorination furnace with chlorine gas at 810℃ for melt chlorination dehydration. It has high energy consumption, large amount of chlorine gas used, and serious environmental pollution.
[0007] The dehydration method under hydrogen chloride protective atmosphere is to evaporate and granulate the MgCl2 solution first, and then pass it through two stages of fluidized bed drying in sequence. After the first stage of fluidized bed drying, dihydrate MgCl2 particles can be obtained. The last stage of fluidized bed is a hydrogen chloride atmosphere, which can suppress the reverse reaction while drying MgCl2. It is the most advanced method for dehydrating magnesium chloride. However, its process flow is long, the dehydration process is difficult to control, and it is prone to problems such as tower plate blockage and powder explosion, which affects the quality of anhydrous magnesium chloride. Summary of the invention
[0008] In order to solve the problems in the prior art, this utility model patent designs a metal magnesium production line to solve the problems of high energy consumption, long process flow and high pollution in the preparation process of sewage magnesium chloride in the existing electrolytic magnesium production system.
[0009] The technical solution adopted by the utility model is that the metal magnesium production line comprises a magnesium ore dissolution and separation device, a high-concentration magnesium chloride solution preparation device, a two-stage fluidized bed drying device and a magnesium electrolysis device which are arranged in sequence.
[0010] Furthermore, the two-stage fluidized bed drying device includes a primary fluidized bed and a secondary fluidized bed, the primary fluidized bed is connected to a spray feeding device, an air heating and air supply device and an exhaust gas treatment system, and the feed pipeline of the spray feeding device is connected to a high-concentration magnesium chloride solution preparation device.
[0011] Furthermore, the secondary fluidized bed is connected to an HCl heating device and an HCl tail gas recycling system.
[0012] Furthermore, the feed pipe of the spray feeding device is arranged at the bottom side of the feed end of the primary fluidized bed, and a plurality of nozzles with nozzles facing upward are arranged on the feed pipe. The feed pipe is connected to the high-concentration magnesium chloride solution preparation device and the high-pressure gas source through a pressurized pipeline.
[0013] Furthermore, the tail gas treatment system includes a first spray tower and an exhaust fan which are connected in sequence by pipelines, and the air inlet end pipeline of the first spray tower is connected to the exhaust port of the primary fluidized bed.
[0014] Furthermore, the HCl tail gas recycling system comprises a quencher, a second spray tower, a dehumidifying moving bed and a circulating fan connected in sequence, the air outlet pipeline of the secondary fluidized bed is connected to the quencher, and the air outlet pipeline of the circulating fan is connected to the HCl heating device.
[0015] Furthermore, the magnesium metal production line also includes a hydrochloric acid preparation system, which includes an HCl synthesis furnace, and the chlorine released by the magnesium electrolysis device is collected and input into the HCl synthesis furnace.
[0016] Furthermore, the magnesium ore dissolution and separation device comprises a magnesium ore dissolution tank, a crude liquid standing separation tank and a low-concentration magnesium chloride solution storage tank which are connected in sequence by pipelines, a multi-stage filter is arranged on the connecting pipeline between the crude liquid standing separation tank and the low-concentration magnesium chloride solution storage tank, the high-concentration magnesium chloride solution preparation device comprises an evaporation concentrator and a high-concentration magnesium chloride solution storage tank, the evaporation concentrator pipeline is connected to the low-concentration magnesium chloride solution storage tank, and the high-concentration magnesium chloride solution storage tank is connected to the spray feeding device of the primary fluidized bed.
[0017] Furthermore, the first spray tower and the second spray tower are both provided with a circulating spray device, the spray liquid of the circulating spray devices of the first spray tower and the second spray tower is both from a low-concentration magnesium chloride solution storage tank, and the circulating spray device is provided with a branch pipeline connected to the feed end of the evaporation concentrator.
[0018] Furthermore, a jacket is provided outside the HCl synthesis furnace, steam-making circulating water is passed through the jacket, the steam outlet pipeline of the jacket is connected to the steam heating pipe of the evaporation concentrator, and the condensed water of the evaporation concentrator is input into the hydrochloric acid preparation system.
[0019] Compared with the prior art, the advancement of the magnesium metal production line designed by the utility model patent is:
[0020] (1) The magnesium metal production line adopts the electrolytic magnesium production process, which has low energy consumption, small waste emissions and is environmentally friendly;
[0021] (2) The magnesium metal production line is equipped with an evaporation and concentration device to transport a high-concentration magnesium chloride solution to the spray granulation device, which facilitates the rapid dehydration of magnesium chloride in the primary fluidized bed to prepare magnesium chloride dihydrate;
[0022] (3) The magnesium metal production line completes the dehydration and granulation of magnesium chloride in a primary fluidized bed to produce dihydrate magnesium chloride particles, which greatly shortens the process flow of anhydrous magnesium chloride, reduces the energy consumption of the system, and improves the preparation efficiency of anhydrous magnesium chloride;
[0023] (4) The magnesium metal production line is equipped with an acid production system that can recycle the chlorine produced by electrolysis. The secondary fluidized bed adopts an HCl tail gas recycling system to recycle the HCl atmosphere gas used for drying and heating, thereby reducing the emission of chlorine and HCl gases in the magnesium metal production line, which is green and economical.
[0024] (5) The heat generated by the acid production system of the magnesium metal production line can be used to produce steam to heat the evaporation and concentration device. At the same time, the condensed water generated by the evaporation and concentration device can be recovered for the production of hydrochloric acid. The spray liquid of the circulating spray device of the first spray tower and the second spray tower comes from the low-concentration magnesium chloride solution storage tank. The low-concentration magnesium chloride solution is used to absorb the magnesium chloride powder in the exhaust gas. After the solution concentration is increased, it is transported to the evaporation concentrator through the branch pipeline of the circulating spray device, thereby achieving exhaust gas purification and recycling of materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a schematic diagram of the process structure of the magnesium metal production line.
[0026] Figure 2 It is a schematic diagram of the structure of a two-stage fluidized bed drying device.
[0027] In the figure, 1 is a magnesium ore dissolving device, 2 is a magnesium chloride solution refining device, 3 is a primary fluidized bed, 4 is a secondary fluidized bed, 5 is a magnesium electrolysis device, 6 is a hydrochloric acid preparation system, 11 is a magnesium ore dissolving tank, 12 is a crude liquid static separation tank, 13 is a low-concentration magnesium chloride solution storage tank, 21 is an evaporation concentrator, 22 is a high-concentration magnesium chloride solution storage tank, 31 is a liquid inlet pipeline, 32 is a nozzle, 33 is an air heating and air supply device, 34 is a first spray tower, 35 is an exhaust fan, 41 is a HCl heating device, 42 is a quencher, 43 is a second spray tower, 44 is a dehumidification moving bed, 45 is a circulating fan, and 61 is a HCl synthesis furnace. DETAILED DESCRIPTION
[0028] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the utility model are clearly and completely described, and the described embodiments are only embodiments of a part of the invention, not all of it. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention.
[0029] like Figure 1 , 2 As shown, the utility model patent designs an embodiment of a metal magnesium production line. In this embodiment, the metal magnesium production line includes a magnesium ore dissolution and separation device 1, a high-concentration magnesium chloride solution preparation device 2, a two-stage fluidized bed drying device, a magnesium electrolysis device 5 and a hydrochloric acid preparation system 6.
[0030] The magnesium ore dissolving and separating device 1 comprises a magnesium ore dissolving tank 11, a crude liquid standing separation tank 12 and a low-concentration magnesium chloride solution storage tank 13 connected in sequence by pipelines. The magnesium ore dissolving tank 11 is used to soak and dissolve the magnesium ore with hydrochloric acid, and the dissolved crude liquid is transported to the crude liquid standing separation tank 12 after coarse filtration. A multi-stage filter is arranged on the connecting pipeline between the crude liquid standing separation tank 12 and the low-concentration magnesium chloride solution storage tank 13. The dissolved crude liquid is further standing and precipitated in the crude liquid standing separation tank 12. After the supernatant is extracted and impurities in the solution are removed by the multi-stage filter, it is temporarily stored in the low-concentration magnesium chloride solution storage tank 13.
[0031] The high concentration magnesium chloride solution preparation device 2 comprises an evaporation concentrator 21 and a high concentration magnesium chloride solution storage tank 22, the evaporation concentrator 21 pipeline is connected to the low concentration magnesium chloride solution storage tank 13, and the evaporation concentration device 3 can select any one of a flash tank, a rising film evaporator, a falling film evaporator, and a multiple effect evaporator, and the main function is to concentrate the low concentration magnesium chloride solution after impurity removal to a high concentration magnesium chloride solution of 50% concentration. The concentrated magnesium chloride solution is temporarily stored in the high concentration magnesium chloride solution storage tank 22. The high concentration magnesium chloride solution storage tank 22 conveys a high concentration magnesium chloride solution to the fluidized bed drying device.
[0032] The two-stage fluidized bed drying device includes a primary fluidized bed 3 and a secondary fluidized bed 4. The primary fluidized bed 3 is connected to a spray feeding device, an air heating and air supply device 33 and an exhaust gas treatment system. The feed pipe 31 of the spray feeding device 3 is arranged at the bottom side of the feed end of the primary fluidized bed 3, and a plurality of nozzles 32 with nozzles facing upward are arranged on the feed pipe 31. The feed pipe 31 is connected to the high-concentration magnesium chloride solution storage tank 22 of the high-concentration magnesium chloride solution preparation device 2 and a high-pressure gas source through a pressurized pipeline. The exhaust gas treatment system includes a first spray tower 34 and an exhaust fan 35 connected in sequence by pipelines. The air inlet end pipeline of the first spray tower 34 is connected to the exhaust port of the primary fluidized bed 3, and the exhaust fan 35 provides negative pressure power for the exhaust gas circulation.
[0033] The secondary fluidized bed 4 is connected to an HCl heating device 41 and an HCl tail gas recycling system. The HCl tail gas recycling system includes a quencher 42, a second spray tower 43, a dehumidifying moving bed 44 and a circulating fan 45 which are connected in sequence. The tail gas outlet pipeline of the secondary fluidized bed 4 is connected to the quencher 42, and the air outlet pipeline of the circulating fan 45 is connected to the HCl heating device 41 to provide power for the circulation of the HCl tail gas. The purified HCl tail gas re-enters the HCl heating device 41, is heated and then sent to the secondary fluidized bed 4 to achieve the recycling of the HCl tail gas.
[0034] The first spray tower 34 and the second spray tower 43 are both provided with a circulating spray device, and the spray liquid of the circulating spray devices of the first spray tower 34 and the second spray tower 43 is both from the low-concentration magnesium chloride solution storage tank 13. The circulating spray device is provided with a branch pipeline connected to the feed end of the evaporation concentrator 21.
[0035] The high-concentration magnesium chloride solution is granulated and dehydrated in the primary fluidized bed 3. The nozzle 32 is driven by the high-pressure airflow to spray the high-concentration magnesium chloride solution into the primary fluidized bed 3. The bottom of the primary fluidized bed 3 is fed with heated high-temperature air by the air heating air supply device 33 to form fluidizing air, and the heating temperature in the bed is maintained at about 160°C-180°C. The magnesium chloride in the bed is dried, dehydrated, and granulated to obtain magnesium chloride dihydrate particles, which are discharged from the discharge end. The wet tail gas is discharged from the exhaust port at the top of the primary fluidized bed 3, enters the first spray tower 35 through the action of the exhaust fan 36, and is washed to remove the magnesium chloride powder entrained in the tail gas and then emptied.
[0036] The magnesium chloride dihydrate material enters the secondary fluidized bed 4, and the HCl heating device 41 sends high-temperature HCl gas into the air inlet at the bottom of the secondary fluidized bed 4 to form an atmosphere, and the temperature in the secondary fluidized bed 4 is maintained at 260°C-280°C, and the magnesium chloride dihydrate material is dried and dehydrated to anhydrous magnesium chloride. The wet HCl tail gas is discharged from the top of the secondary fluidized bed 4 and enters the HCl tail gas recycling system. The HCl tail gas is provided with circulation power by the circulating fan 45. After cooling by the quench cooler 42, it enters the second spray tower for spray washing to remove the magnesium chloride powder entrained in the tail gas, and then it is dehumidified by the dehumidification moving bed 44 and sent back to the HCl heating device 41 to recover the HCl gas for recycling.
[0037] The spray liquid after washing in the first spray tower 35 and the second spray tower 43 contains a large amount of magnesium chloride and can be sent to the evaporation concentrator 21 as a low-concentration magnesium chloride solution.
[0038] The anhydrous magnesium chloride produced by the secondary fluidized bed 4 is transported to the magnesium electrolysis device 5 for molten electrolysis to prepare metallic magnesium. The chlorine gas produced by the electrolysis of magnesium chloride is collected and sent to the HCl synthesis furnace 61 of the hydrochloric acid preparation system 6. The HCl synthesis furnace 61 is a jacket structure. Steam-making circulating water is passed into the jacket. The heat generated in the furnace is used to produce steam. The produced steam can be transported to the evaporation concentrator 21 for heating. The evaporated condensed water of the evaporation concentrator 21 contains a large amount of hydrochloric acid, which can be input into the hydrochloric acid preparation system 6 for recycling.
[0039] The above contents are only preferred embodiments of the present invention and cannot be used to limit the scope of implementation of the present invention. That is, any simple equivalent changes and modifications made according to the claims and description of the present invention are still within the scope of the present invention.
Claims
1. A magnesium metal production line, characterized in that: The magnesium metal production line comprises a magnesium ore dissolution and separation device, a high-concentration magnesium chloride solution preparation device, a two-stage fluidized bed drying device and a magnesium electrolysis device which are arranged in sequence.
2. A magnesium metal production line according to claim 1, characterized in that: The two-stage fluidized bed drying device comprises a primary fluidized bed and a secondary fluidized bed, the primary fluidized bed is connected with a spray feeding device, an air heating and air supply device and an exhaust gas treatment system, and the feeding pipeline of the spray feeding device is connected with a high-concentration magnesium chloride solution preparation device.
3. A magnesium metal production line according to claim 2, characterized in that: The secondary fluidized bed is connected with an HCl heating device and an HCl tail gas recycling system.
4. A magnesium metal production line according to claim 3, characterized in that: The feed pipe of the spray feeding device is arranged at the bottom side of the feed end of the primary fluidized bed, and a plurality of nozzles with nozzles facing upward are arranged on the feed pipe. The feed pipe is connected to the high-concentration magnesium chloride solution preparation device and the high-pressure gas source through a pressurized pipeline.
5. A magnesium metal production line according to claim 4, characterized in that: The tail gas treatment system comprises a first spray tower and an exhaust fan which are connected in sequence by pipelines, and the air inlet end pipeline of the first spray tower is connected to the exhaust port of the primary fluidized bed.
6. A magnesium metal production line according to claim 5, characterized in that: The HCl tail gas recycling system comprises a quencher, a second spray tower, a dehumidifying moving bed and a circulating fan which are connected in sequence, wherein the air outlet pipeline of the secondary fluidized bed is connected to the quencher, and the air outlet pipeline of the circulating fan is connected to the HCl heating device.
7. A magnesium metal production line according to claim 6, characterized in that: The magnesium metal production line also includes a hydrochloric acid preparation system, which includes an HCl synthesis furnace. The chlorine gas released by the magnesium electrolysis device is collected and input into the HCl synthesis furnace.
8. A magnesium metal production line according to claim 7, characterized in that: The magnesium ore dissolution and separation device comprises a magnesium ore dissolution tank, a crude liquid standing separation tank and a low-concentration magnesium chloride solution storage tank which are connected in sequence by pipelines, a multi-stage filter is arranged on the connecting pipeline between the crude liquid standing separation tank and the low-concentration magnesium chloride solution storage tank, the high-concentration magnesium chloride solution preparation device comprises an evaporation concentrator and a high-concentration magnesium chloride solution storage tank, the evaporation concentrator pipeline is connected to the low-concentration magnesium chloride solution storage tank, and the high-concentration magnesium chloride solution storage tank is connected to the spray feeding device of the primary fluidized bed.
9. A magnesium metal production line according to claim 8, characterized in that: The first spray tower and the second spray tower are both provided with a circulating spray device, the spray liquid of the circulating spray devices of the first spray tower and the second spray tower is both from the low-concentration magnesium chloride solution storage tank, and the circulating spray device is provided with a branch pipeline connected to the feed end of the evaporation concentrator.
10. A magnesium metal production line according to claim 9, characterized in that: A jacket is provided outside the HCl synthesis furnace, steam-making circulating water is passed through the jacket, a steam outlet pipeline of the jacket is connected to a steam heating pipe of an evaporation concentrator, and condensed water of the evaporation concentrator is input into a hydrochloric acid preparation system.