Lipidolite lithium extraction pyrogenic process section waste heat recovery system

Abstract

The utility model discloses a lepidolite lithium extraction pyrogenic process section waste heat recovery system which is characterized in that a preheating kiln is provided with a feed port and a discharge port, and the discharge port of the preheating kiln is connected with the feed port of a roasting kiln; the air blower is arranged at the position close to a discharging port of the roasting kiln, so that high-temperature smoke in the roasting kiln sequentially passes through a feeding port of the roasting kiln and a discharging port of the preheating kiln in the direction opposite to the material moving direction to enter the preheating kiln. A discharge port of the roasting kiln is connected with a feed port of the cooling kiln; the air cooler is arranged at a position near a feeding hole of the cooling kiln; the exhaust assembly is connected with a part near a discharge port of the cooling kiln and a part near a discharge port of the preheating kiln and is used for conveying hot air in the cooling kiln into the preheating kiln; and the waste heat recovery device is used for recovering residual waste heat in the preheating kiln. According to the utility model, the waste heat of the pyrogenic process section in the process of extracting lithium from lepidolite can be comprehensively, efficiently and economically recycled, and the preheating effect of materials can be effectively enhanced.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, and in particular to a waste heat recovery system for lithium extraction from lithium mica using a pyrometallurgical process. Background Technology

[0002] Lithium extraction from lepidolite typically employs the sulfate roasting method. In the pyrometallurgical stage, lepidolite concentrate is preheated in a preheating kiln, then calcined at high temperatures in a roasting kiln, followed by cooling in a cooling kiln to form lithium-containing clinker. During this process, the temperature of the high-temperature flue gas in the roasting kiln and the lithium-containing clinker in the cooling kiln can reach 900–1000°C. However, current practices present challenges in waste heat recovery from the pyrometallurgical stage of lepidolite extraction. Either only the waste heat from the roasting kiln or only the waste heat from the cooling kiln is recovered, resulting in a single source of waste heat. Because the high-temperature flue gas waste heat from the roasting kiln and the clinker waste heat from the cooling kiln are not simultaneously and effectively utilized, the waste heat resources of the pyrometallurgical stage are wasted. Furthermore, some current waste heat recovery technologies for the pyrometallurgical stage of lepidolite extraction are costly. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a waste heat recovery system for the pyrometallurgical stage of lithium extraction from lepidolite, which can comprehensively, efficiently, and economically recover the waste heat from the pyrometallurgical stage during the lithium extraction process from lepidolite, and effectively enhance the preheating effect of the material.

[0004] The waste heat recovery system for lithium extraction from lithium mica according to an embodiment of the present invention includes a preheating kiln, a roasting kiln, a cooling kiln, a blower, a cooler, an exhaust assembly, and a waste heat recovery device.

[0005] The preheating kiln has a feed inlet and a discharge outlet. The discharge outlet of the preheating kiln is connected to the feed inlet of the roasting kiln so that the material in the preheating kiln can enter the roasting kiln.

[0006] The blower is located near the discharge port of the roasting kiln and is used to blow air into the roasting kiln, so that the high-temperature flue gas in the roasting kiln passes through the feed port of the roasting kiln and the discharge port of the preheating kiln in the opposite direction to the material movement.

[0007] The discharge port of the roasting kiln is connected to the inlet of the cooling kiln so that the material in the roasting kiln enters the cooling kiln.

[0008] The air cooler is located near the feed inlet of the cooling kiln and is used to blow air into the cooling kiln.

[0009] The exhaust assembly is connected to the part near the discharge port of the cooling kiln and the part near the discharge port of the preheating kiln, and is used to transport hot air from the cooling kiln to the preheating kiln.

[0010] The waste heat recovery device is used to recover the remaining waste heat in the preheating kiln.

[0011] According to the waste heat recovery system of the lithium mica lithium extraction pyrometallurgical section of this utility model embodiment, a blower is arranged near the discharge port of the calcining kiln to make the high-temperature flue gas in the calcining kiln flow against the material movement direction from the discharge port of the calcining kiln to the inlet port of the preheating kiln. This allows the high-temperature flue gas to fully and efficiently preheat the material before it enters the calcining kiln. Simultaneously, an exhaust assembly is installed between the discharge ports of the cooling kiln and the preheating kiln to allow the hot air near the discharge port of the cooling kiln to flow against the material movement direction from the discharge port of the cooling kiln to the inlet port of the preheating kiln. The airflow direction ensures that the hot air fully and efficiently preheats the material before it enters the calcining kiln. Therefore, the material entering the calcining kiln utilizes the waste heat from both the high-temperature flue gas of the calcining kiln and the hot air from the cooling kiln for preheating, greatly enhancing the preheating effect. Furthermore, the residual heat from the high-temperature flue gas of the calcining kiln and the residual heat from the hot air from the cooling kiln near the feed inlet of the preheating kiln can be recovered by a waste heat recovery device, thus achieving comprehensive and full waste heat recovery, greatly reducing energy consumption, avoiding the waste of waste heat resources, constructing an efficient and cyclical heat energy recovery system, and reducing production costs.

[0012] In summary, the waste heat recovery system for the pyrometallurgical section of lithium extraction from lepidolite in this embodiment of the present invention can comprehensively, efficiently, and economically recover the waste heat from the pyrometallurgical section during the lithium extraction process from lepidolite, and can effectively enhance the preheating effect of the material.

[0013] In some embodiments, the heights of the preheating kiln, the calcining kiln, and the cooling kiln are arranged sequentially from high to low.

[0014] In some embodiments, the system further includes a first feeding trough, the upper end of which is connected to the discharge port of the preheating kiln, and the lower end of which is connected to the feed port of the calcining kiln.

[0015] In some embodiments, the first feeding trough is provided with a perforated screen structure.

[0016] In some embodiments, a second feeding trough is further included, the upper end of which is connected to the discharge port of the roasting kiln, and the lower end of which is connected to the feed port of the cooling kiln.

[0017] In some embodiments, the second feeding trough is S-shaped.

[0018] In some embodiments, a plurality of guide plates are provided on the inner wall surface of the second feeding trough.

[0019] In some embodiments, both the exterior of the first feeding trough and the exterior of the second feeding trough are provided with heat insulation components.

[0020] In some embodiments, the exhaust assembly includes an exhaust pipe and a first induced draft fan. The two ends of the exhaust pipe are respectively connected to a portion near the outlet of the cooling kiln and a portion near the outlet of the preheating kiln. The first induced draft fan is disposed inside the exhaust pipe.

[0021] In some embodiments, the exhaust duct is provided with an insulation pipe on its exterior.

[0022] In some embodiments, both the inner wall of the preheating kiln and the inner wall of the cooling kiln are provided with lifting plates.

[0023] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of the waste heat recovery system for lithium extraction from lithium mica in the pyrometallurgical process of this utility model.

[0026] Figure 2 This is a schematic diagram of the internal structure of the first feeding tank of the waste heat recovery system for lithium extraction from lithium mica in the pyrometallurgical process of this utility model.

[0027] Figure 3 This is a schematic diagram of the internal structure of the second feeding tank of the lithium mica lithium extraction pyrometallurgical waste heat recovery system of this utility model.

[0028] Figure label:

[0029] Lithium mica lithium extraction pyrometallurgical stage waste heat recovery system 1000; feeding assembly 1; raw material silo 101; conveyor 102; preheating kiln 2; roasting kiln 3; cooling kiln 4; blower 5; air cooler 6; exhaust assembly 7; exhaust pipe 701; first induced draft fan 702; waste heat recovery device 8; first feeding trough 9; perforated screen structure 901; second feeding trough 10; guide plate 1001; second induced draft fan 11; cyclone separator 12. Detailed Implementation

[0030] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0031] The following is combined with Figures 1 to 3 This invention relates to a waste heat recovery system 1000 for lithium extraction from lithium mica using a pyrometallurgical process, as described in an embodiment of the present invention.

[0032] like Figures 1 to 3 As shown, the waste heat recovery system 1000 for lithium extraction from lithium mica in the pyrometallurgical process according to an embodiment of the present invention includes a preheating kiln 2, a roasting kiln 3, a cooling kiln 4, a blower 5, a cold air blower 6, an exhaust assembly 7, and a waste heat recovery device 8.

[0033] The preheating kiln 2 has a feed inlet and a discharge outlet. The feed inlet of the preheating kiln 2 is used to supply the material, namely lepidolite raw material. The discharge outlet of the preheating kiln 2 is connected to the feed inlet of the calcining kiln 3 so that the material in the preheating kiln 2 can enter the calcining kiln 3. After being preheated in the preheating kiln 2, the material passes through the discharge outlet of the preheating kiln 2 and the feed inlet of the calcining kiln 3 in sequence into the calcining kiln 3 for high-temperature calcination. At the same time, high-temperature flue gas is generated in the calcining kiln 3.

[0034] Blower 5 is positioned near the discharge port of the calcining kiln 3 to blow air into the calcining kiln 3. This causes the high-temperature flue gas in the calcining kiln 3 to flow against the direction of material movement, passing sequentially through the feed port of the calcining kiln 3 and the discharge port of the preheating kiln 2 before entering the preheating kiln 2. Since the material moves from the feed port to the discharge port of the calcining kiln 3, the high-temperature flue gas would flow along with the material without blower 5. Therefore, by arranging blower 5 near the discharge port of the calcining kiln 3, the high-temperature flue gas in the calcining kiln 3 flows back against the direction of material movement, passing sequentially through the feed port of the calcining kiln 3 and the discharge port of the preheating kiln 2 before entering the preheating kiln 2. In the preheating kiln 2, the high-temperature flue gas flows against the direction of material movement towards the feed port of the preheating kiln 2. The high-temperature flue gas preheats the material in the preheating kiln 2 and along the path from the calcining kiln 3 to the preheating kiln 2. In other words, the material entering the roasting kiln 3 was preheated using the waste heat from the high-temperature flue gas in the roasting kiln 3.

[0035] The discharge port of the calcining kiln 3 is connected to the inlet of the cooling kiln 4 so that the material in the calcining kiln 3 can enter the cooling kiln 4. After the preheated material undergoes high-temperature calcination in the calcining kiln 3, it passes through the discharge port of the calcining kiln 3 and the inlet of the cooling kiln 4 in sequence to enter the cooling kiln 4 for cooling. The cooled material is the required cooled clinker.

[0036] A cold air blower 6 is positioned near the feed inlet of the cooling kiln 4 to blow cold air into the kiln. Since the material moves from the feed inlet to the discharge outlet of the cooling kiln 4, the cold air blown into the kiln by the cold air blower 6 near the feed inlet allows the cold air to flow along with the material from the feed inlet to the discharge outlet. Through heat exchange between the cold air and the high-temperature calcined material, the material is efficiently and thoroughly cooled to obtain the desired clinker, which is then discharged from the discharge outlet of the cooling kiln 4 (see [link]). Figure 1 (The dotted line in the image) Meanwhile, the air flowing to the vicinity of the discharge port of the cooling kiln 4 is hot air, and the temperature of the air flowing to the vicinity of the discharge port of the cooling kiln 4 is relatively higher than the temperature of the air in other parts of the cooling kiln 4.

[0037] The exhaust assembly 7 connects to the area near the discharge port of the cooling kiln 4 and the area near the discharge port of the preheating kiln 2, and is used to transport hot air from the cooling kiln 4 to the preheating kiln 2. Since the air temperature near the discharge port of the cooling kiln 4 is higher than that of other parts of the cooling kiln 4, it is considered hot air. Therefore, by connecting the exhaust assembly 7 to the area near the discharge port of the cooling kiln 4 and the area near the discharge port of the preheating kiln 2, the hot air from the area near the discharge port of the cooling kiln 4 can be transported from the area near the discharge port of the preheating kiln 2 to the preheating kiln 2, and the hot air flows against the direction of material movement towards the feed inlet of the preheating kiln 2, thus preheating the material in the preheating kiln 2. In other words, the material entering the calcining kiln 3 is preheated not only by utilizing the waste heat from the high-temperature flue gas of the calcining kiln 3, but also by utilizing the waste heat from the hot air of the cooling kiln 4 (i.e., the waste heat of the clinker in the cooling kiln).

[0038] Waste heat recovery device 8 is used to recover the residual waste heat inside the preheating kiln 2. The residual heat from the high-temperature flue gas of the calcining kiln 3 and the residual heat from the hot air of the cooling kiln 4, located near the discharge port of the preheating kiln 2, can be recovered by waste heat recovery device 8, thereby achieving comprehensive and sufficient waste heat recovery in the pyrometallurgical section. Optionally, waste heat recovery device 8 can be a conventional waste heat recovery device or other types of waste heat recovery devices.

[0039] According to the waste heat recovery system 1000 of the lithium mica lithium extraction pyrometallurgical section of this utility model embodiment, a blower 5 is arranged near the discharge port of the calcining kiln 3, so that the high-temperature flue gas in the calcining kiln 3 flows in the opposite direction to the material movement direction from the discharge port of the calcining kiln 3 to the feed port of the preheating kiln 2. This allows the high-temperature flue gas to fully and efficiently preheat the material before it enters the calcining kiln 3. At the same time, an exhaust assembly 7 is installed between the discharge port of the cooling kiln 4 and the discharge port of the preheating kiln 2, so that the hot air near the discharge port of the cooling kiln 4 flows in the opposite direction to the feed port of the preheating kiln 2 through the exhaust assembly 7. The hot air flows in the direction of material movement, allowing it to fully and efficiently preheat the material before it enters the calcining kiln 3. Therefore, the material entering the calcining kiln 3 utilizes the waste heat from both the high-temperature flue gas of the calcining kiln 3 and the hot air from the cooling kiln 4 for preheating, significantly enhancing the preheating effect. Furthermore, the residual heat from the high-temperature flue gas of the calcining kiln 3 and the residual heat from the hot air of the cooling kiln 4 near the feed inlet of the preheating kiln 2 can be recovered by the waste heat recovery device 8, thus achieving comprehensive and thorough waste heat recovery. This greatly reduces energy consumption, avoids the waste of waste heat resources, and constructs an efficient and cyclical heat recovery system, reducing production costs.

[0040] In summary, the waste heat recovery system 1000 for lithium extraction from pyrometallurgical processes of lepidolite in this embodiment of the present invention can comprehensively, efficiently, and economically recover the waste heat from the pyrometallurgical process during lithium extraction from lepidolite.

[0041] In some embodiments, the preheating kiln 2, the calcining kiln 3, and the cooling kiln 4 are arranged at heights from high to low. This facilitates the automatic entry of material in the preheating kiln 2 into the calcining kiln 3 by its own gravity, and the automatic entry of material in the calcining kiln 3 into the cooling kiln 4 by its own gravity.

[0042] In some embodiments, a first feeding trough 9 is further included. The upper end of the first feeding trough 9 is connected to the discharge port of the preheating kiln 2, and the lower end of the first feeding trough 9 is connected to the inlet of the calcining kiln 3. In this way, the material in the preheating kiln 2 falls from the discharge port of the preheating kiln 2 along the first feeding trough 9 under its own gravity and enters the calcining kiln 3 through the inlet. Simultaneously, the high-temperature flue gas in the calcining kiln 3 enters the first feeding trough 9 from the inlet of the calcining kiln 3 and rises along the first feeding trough 9, then enters the preheating kiln 2 from the discharge port of the preheating kiln 2. Thus, in the first feeding trough 9, the high-temperature flue gas exchanges heat with the material, preheating the material before it enters the calcining kiln 3, enhancing the preheating effect. It should be noted that the first feeding trough 9 can be arranged vertically or at an angle.

[0043] In some embodiments, such as Figure 2As shown, the first feeding trough 9 is equipped with a perforated screen structure 901, which makes the material evenly distributed in the first feeding trough 9, increases the contact area between the high-temperature flue gas and the material in the roasting kiln 3, and can also increase the residence time of the material, so that the high-temperature flue gas and the material are in contact for a longer time, and the heat exchange and preheating effect is more significant.

[0044] Priority is that the perforated screen structure 901 can be set in multiple layers, so that the material is more evenly distributed in the first feeding trough 9, increasing the contact area between the high-temperature flue gas and the material in the roasting kiln 3. In addition, the residence time of the material can be further increased, so that the high-temperature flue gas and the material are in contact for a longer time, and the heat exchange and preheating effect is more significant.

[0045] In some embodiments, a second feeding trough 10 is also included. The upper end of the second feeding trough 10 is connected to the discharge port of the calcining kiln 3, and the lower end of the second feeding trough 10 is connected to the feed port of the cooling kiln 4. In this way, the material in the calcining kiln 3 falls from the discharge port of the calcining kiln 3 along the second feeding trough 10 under its own gravity and enters the cooling kiln 4 through the feed port of the cooling kiln 4, where it exchanges heat with the cold air blown in by the cold air blower 6.

[0046] In some embodiments, the second feeding trough 10 is S-shaped. The S-shaped second feeding trough 10 can repeatedly impact and break up the clinker clumps after high-temperature calcination, which helps to increase the heat exchange area of ​​the subsequent cooling process and improve the heat exchange efficiency.

[0047] In some embodiments, a plurality of guide plates 1001 are provided on the inner wall surface of the second feeding trough 10. The plurality of guide plates 1001 can repeatedly crush the molten and agglomerated material by utilizing the material's own gravity, thereby achieving the purpose of crushing and increasing the cooling effect of the material in the cooling kiln 4.

[0048] Preferably, multiple guide plates 1001 are distributed on opposite sides of the inner wall of the second feeding trough 10, which can repeatedly crush the molten and agglomerated material by utilizing the material's own gravity, thereby achieving the purpose of crushing and increasing the cooling effect of the material in the cooling kiln 4.

[0049] In some embodiments, both the exterior of the first feeding trough 9 and the exterior of the second feeding trough 10 are provided with heat insulation components (not shown in the figure). The heat insulation component on the exterior of the first feeding trough 9 can significantly reduce the waste heat loss of the high-temperature flue gas, while the heat insulation component on the exterior of the second feeding trough 10 is used to keep the high-temperature materials warm, avoid preheating loss, and facilitate waste heat collection.

[0050] In some embodiments, the exhaust assembly 7 includes an exhaust pipe 701 and a first induced draft fan 702. The two ends of the exhaust pipe 701 are connected to locations near the discharge port of the cooling kiln 4 and near the discharge port of the preheating kiln 2, respectively. The first induced draft fan 702 is disposed within the exhaust pipe 701. The first induced draft fan 702 primarily provides power, drawing hot air from the location near the discharge port of the cooling kiln 4 into the exhaust pipe 701, allowing the hot air to enter the preheating kiln 2 from the location near the discharge port of the preheating kiln 2 along the exhaust pipe 701.

[0051] In some embodiments, an insulation pipe (not shown in the figure) is provided on the outside of the exhaust duct 701. The insulation pipe can significantly reduce the heat loss of hot air when hot air passes through the exhaust duct 701.

[0052] In some embodiments, both the inner walls of the preheating kiln 2 and the cooling kiln 4 are equipped with lifting plates (not shown in the figure). The lifting plates in the preheating kiln 2 can increase the material dispersion area, which is beneficial to improving the material preheating effect; the lifting plates in the cooling kiln 4 can increase the material dispersion area, which is beneficial to improving the material heat exchange effect.

[0053] In some embodiments, the system further includes a second induced draft fan 11 and a cyclone separator 12. The inlet of the second induced draft fan 11 is connected to a portion near the feed inlet of the preheating kiln 2, and the outlet of the second induced draft fan 11 is connected to the inlet of the cyclone separator 12. A waste heat recovery device 8 is connected to the outlet of the cyclone separator 12, and the waste heat recovery device 8 is equipped with a filter screen. The second induced draft fan 11 primarily provides power, introducing the high-temperature flue gas and hot air near the feed inlet of the preheating kiln 2 into the cyclone separator 12 for dust removal. The dust-removed high-temperature flue gas and hot air then enter the waste heat recovery device 8 for residual heat recovery and utilization. Since the waste heat recovery device 8 is equipped with a filter screen, it can further filter dust.

[0054] In some embodiments, a feeding assembly 1 is also included, which is connected to the feed inlet of the preheating kiln 2 and is used to feed material into the preheating kiln 2 so that the material is preheated in the preheating kiln 2.

[0055] Specifically, the feeding assembly 1 includes a raw material silo 101 and a conveyor 102. The raw material silo 101 is connected to the feed inlet of the preheating kiln 2 via the conveyor 102. The raw material silo 101 stores the lepidolite material to be preheated, and the conveyor 102 transports the material discharged from the raw material silo 101 to the feed inlet of the calcining kiln 3. Optionally, the conveyor 102 can be a belt conveyor 102.

[0056] Optionally, the feeding assembly 1 is positioned higher than the preheating kiln 2 to facilitate the material entering the preheating kiln 2 by its own gravity. Alternatively, the feeding assembly 1 can be positioned no higher than the preheating kiln 2, and the feeding assembly 1 can be powered to transport the material to the feed inlet of the preheating kiln 2.

[0057] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A waste heat recovery system for lithium extraction from lepidolite pyrometallurgical processes, characterized in that, It includes a preheating kiln, a roasting kiln, a cooling kiln, a blower, a cooler, an exhaust system, and a waste heat recovery device; The preheating kiln has a feed inlet and a discharge outlet. The discharge outlet of the preheating kiln is connected to the feed inlet of the roasting kiln so that the material in the preheating kiln can enter the roasting kiln. The blower is located near the discharge port of the roasting kiln and is used to blow air into the roasting kiln, so that the high-temperature flue gas in the roasting kiln passes through the feed port of the roasting kiln and the discharge port of the preheating kiln in the opposite direction to the material movement. The discharge port of the roasting kiln is connected to the inlet of the cooling kiln so that the material in the roasting kiln enters the cooling kiln. The air cooler is located near the feed inlet of the cooling kiln and is used to blow air into the cooling kiln. The exhaust assembly is connected to the part near the discharge port of the cooling kiln and the part near the discharge port of the preheating kiln, and is used to transport hot air from the cooling kiln to the preheating kiln. The waste heat recovery device is used to recover the remaining waste heat in the preheating kiln.

2. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to claim 1, characterized in that, The heights of the preheating kiln, the roasting kiln, and the cooling kiln are arranged sequentially from high to low.

3. The waste heat recovery system for lithium extraction from lithium mica in pyrometallurgical processes according to claim 2, characterized in that, It also includes a first feeding trough, the upper end of which is connected to the discharge port of the preheating kiln, and the lower end of which is connected to the feed port of the roasting kiln.

4. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to claim 3, characterized in that, The first feeding trough is equipped with a perforated screen structure.

5. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to claim 3, characterized in that, It also includes a second feeding trough, the upper end of which is connected to the discharge port of the roasting kiln, and the lower end of which is connected to the feed port of the cooling kiln.

6. The waste heat recovery system for lithium extraction from lithium mica in pyrometallurgical processes according to claim 5, characterized in that, The second feeding trough is S-shaped.

7. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to claim 5, characterized in that, Multiple guide plates are provided on the inner wall surface of the second feeding trough.

8. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to claim 5, characterized in that, Both the exterior of the first feeding trough and the exterior of the second feeding trough are equipped with heat insulation components.

9. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to any one of claims 1-8, characterized in that, The exhaust assembly includes an exhaust pipe and a first induced draft fan. The two ends of the exhaust pipe are connected to the parts near the discharge port of the cooling kiln and the parts near the discharge port of the preheating kiln, respectively. The first induced draft fan is installed inside the exhaust pipe.

10. The waste heat recovery system for lithium extraction from lithium mica in pyrometallurgical processes according to claim 9, characterized in that, The exhaust duct is equipped with an external heat insulation pipe.

11. The waste heat recovery system for lithium extraction from lithium mica using pyrometallurgical processes according to any one of claims 1-8, characterized in that, Both the inner walls of the preheating kiln and the inner walls of the cooling kiln are equipped with lifting plates.

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