Combined heat exchange system for laterite-nickel ore leaching flash tanks and preheaters

Abstract

A combined heat exchange system for laterite-nickel ore leaching flash tanks (21, 22, 23) and preheating towers (31, 32, 33), the system comprising a high-pressure reaction kettle (1), the preheating towers (31, 32, 33) and the flash tanks (21, 22, 23), wherein the preheating towers (31, 32, 33) are connected to a feeding port of the high-pressure reaction kettle (1); the flash tanks (21, 22, 23) are connected to a discharging port of the high-pressure reaction kettle (1), and the flash tanks (21, 22, 23) are further in communication with the preheating towers (31, 32, 33) by means of steam pipes; a pressure relief cavity (241) and a buffer assembly (28) are provided in each of the flash tanks (21, 22, 23), wherein the buffer assembly (28) comprises a buffer member (281) and a connecting structure (282) which are connected to each other, and the buffer member (281) has a central protrusion (286) and is provided with a buffer groove (287); and the highest point of the central protrusion (286) is higher than the lowest point of the buffer groove (287), a surface of the central protrusion (286) is connected to a surface of the buffer groove (287), and a fluid falling from a pressure relief cavity (241) can pass through the surface of the central protrusion (286) and slide out from one end to the other end of the buffer groove (287), thereby achieving a buffering effect.

Description

Combined heat exchange system of laterite nickel ore leaching flash tank and preheater Technical Field

[0001] The present invention relates to the technical field of chemical equipment, and in particular to a laterite nickel ore leaching flash tank and preheater combined heat exchange system. Background Art

[0002] Flash evaporation involves transferring high-pressure slurry from a high-pressure reactor into a lower-pressure vessel. The sudden drop in pressure converts the slurry into saturated water vapor and saturated slurry at the lower pressure of the vessel. The boiling point of a substance is proportional to pressure, so decompression can lower the boiling point of the high-pressure, high-temperature slurry, allowing it to enter flash evaporation. The flash tank provides a space for rapid fluid vaporization and vapor-liquid separation.

[0003] There are many types of existing flash tank structures. For example, the existing patent with announcement number CN217612977U discloses a nickel flash tank based on flake caustic soda production, comprising: a tank body; a head, the head being arranged at the top of the tank body; a first temperature measuring tube arranged on the right side inside the head; a first steam pipe arranged at the top of the head; a nitrogen pipe arranged on the left side inside the head; a second steam pipe fixedly installed on the left side of the tank body; a coil arranged at the bottom of the tank body surface, and a buffer plate fixedly installed inside the tank body via a connecting column; and a second temperature measuring tube fixedly installed on the right side of the bottom of the tank body. When flake caustic soda is needed, the water containing alkali is transported into the interior of the tank body through the alkali inlet pipe. During the transportation process, the water passes through the buffer plate to prevent excessive pressure from impacting the head and causing instability of the tank body.

[0004] However, this existing technology still has some shortcomings. For example, the stress-bearing part of the impact plate is suspended inside the tank body, and the impact plate itself does not have a buffering structure. After being impacted by materials for a long time, the impact plate is prone to deformation and loses its buffering effect on the materials. Therefore, it is necessary to further improve the structure of the flash tank.

[0005] Summary of the Invention

[0006] In view of this, it is necessary to provide a combined heat exchange system of a laterite nickel ore leaching flash tank and a preheater to solve the technical problem in the prior art that the stress-bearing part of the anti-collision plate of the existing flash tank is suspended inside the tank body, and the anti-collision plate itself does not have a buffering structure. The anti-collision plate is easily deformed after being impacted by the material for a long time and loses its buffering effect on the material.

[0007] In order to achieve the above technical objectives, the technical solution of the present invention provides a laterite nickel ore leaching flash tank and preheater combined heat exchange system, comprising:

[0008] High-pressure reactor;

[0009] A preheating tower connected to the feed port of the high-pressure reactor;

[0010] A flash tank is connected to the discharge port of the high-pressure reactor, and the flash tank is also connected to the preheating tower through a steam pipe. A pressure relief chamber and a buffer assembly are provided in the flash tank; the buffer assembly includes a buffer part and a connecting structure, one side of the connecting structure is connected to the buffer part, and the other side of the connecting structure is connected to the bottom of the pressure relief chamber; the buffer part has a central protrusion on the side facing away from the connecting structure, and the buffer part is provided with a buffer groove around the central protrusion, and the buffer groove is recessed toward the side of the connecting structure, the highest point of the central protrusion is higher than the lowest point of the buffer groove, and the surface of the central protrusion is connected to the surface of the buffer groove, so that the fluid falling in the pressure relief chamber can pass through the surface of the central protrusion and slide out from one end of the buffer groove to the other end.

[0011] Furthermore, the central protrusion is conical, and the highest point of the central protrusion is higher than any position of the buffer groove.

[0012] Furthermore, the buffer groove is an arc-shaped groove, and one end of the buffer groove is tangent to the surface of the central protrusion.

[0013] Furthermore, one end of the buffer groove away from the central protrusion is tangent to the cavity wall of the pressure relief cavity.

[0014] Furthermore, the connecting structure includes a first elastic frame, a second elastic frame and a connecting piece, the ends of the first elastic frame and the second elastic frame that are close to each other are connected through the connecting piece, the end of the first elastic frame away from the second elastic frame is connected to the buffer member, and the end of the second elastic frame away from the first elastic frame is connected to the bottom of the pressure relief chamber.

[0015] Furthermore, the preheating tower includes a tower body and a heat exchange component arranged inside the tower body, and the heat exchange component is arranged on the inner wall of the tower body.

[0016] Furthermore, there are multiple heat exchange components, and the multiple heat exchange components are arranged in an upper and lower interval inside the tower body.

[0017] Furthermore, the heat exchange assembly includes a first heat exchanger, a second heat exchanger and a connector, the connector connects the first heat exchanger and the second heat exchanger, the first heat exchanger and the second heat exchanger are separated to form a flow port, and the fluid inside the tower body can flow through the first heat exchanger, the flow port and the second heat exchanger in sequence.

[0018] Furthermore, the first heat exchanger and the second heat exchanger are both conical, and in the direction from the first heat exchanger to the second heat exchanger, the cross-sectional area of ​​the first heat exchanger increases, and the cross-sectional area of ​​the second heat exchanger decreases, and the extension path of the first heat exchanger passes through the second heat exchanger.

[0019] Furthermore, the tower body has an air inlet, which is located between the heat exchange component and the bottom of the tower body. The air inlet is used to introduce steam into the interior of the tower body to mix the steam with the fluid flowing through the preheating element.

[0020] Furthermore, the number of the preheating towers is three, namely, a first preheating tower, a second preheating tower and a third preheating tower, and the high-pressure reactor, the first preheating tower, the second preheating tower and the third preheating tower are connected in sequence; the number of the flash tanks is three, namely, a first flash tank, a second flash tank and a third flash tank, and the high-pressure reactor, the first flash tank, the second flash tank and the third flash tank are connected in sequence.

[0021] Furthermore, the first flash tank is connected to the first preheating tower via a steam pipe, the second flash tank is connected to the second preheating tower via a steam pipe, and the third flash tank is connected to the third preheating tower via a steam pipe.

[0022] Compared to the prior art, the present invention has the following beneficial effects: the buffer member within the flash tank of the present invention is located at the bottom of the pressure relief chamber. When impacted by material falling from the pressure relief chamber, the buffer member can transfer a significant portion of the force to the chamber bottom, leaving the buffer member itself bearing less force. Furthermore, the buffer member comprises a central protrusion and a buffer groove. Material falling from the pressure relief chamber can sequentially pass through the central protrusion and slide from one end of the buffer groove to the other, sliding upward. The upwardly sliding material moves in the opposite direction of the subsequent falling material, and their collision can offset a significant amount of the interaction force, thereby achieving a further buffering effect. Therefore, the buffer member is less likely to deform when impacted by material and can be used for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic structural diagram of a laterite nickel ore leaching flash tank and preheater combined heat exchange system according to the present invention;

[0024] FIG2 is a schematic structural diagram of a first flash tank of the present invention;

[0025] FIG3 is a schematic structural diagram of a buffer assembly according to the present invention;

[0026] FIG4 is a schematic structural diagram of the first preheating tower of the present invention. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0028] Referring to Figure 1, the present invention provides a combined heat exchange system 100 for laterite nickel ore leaching, combining a flash tank and a preheater. This heat exchange system 100 is used to smelt laterite nickel ore to extract leached nickel and cobalt. During the discharge process, heat exchange system 100 provides multi-stage pressure relief to protect the equipment. Furthermore, the heat released during the pressure relief process can be recycled, saving energy.

[0029] The heat exchange system 100 includes a high-pressure reactor 1 and a heat exchange device 101, wherein the heat exchange device 101 includes a flash tank 2 and a preheating tower 3. The discharge port of the high-pressure reactor 1 is connected to the flash tank 2, and the slurry leached from the high-pressure reactor 1 can be discharged through the flash tank 2 after pressure release. The flash tank 2 is connected to the preheating tower 3, and the heat released by the flash tank 2 during the pressure release process can be transferred to the preheating tower 3 to preheat the slurry raw materials in the preheating tower 3, so that the heat can be fully utilized. The feed port of the high-pressure reactor 1 is connected to the preheating tower 3, and the slurry raw materials are preheated in the preheating tower 3 before entering the high-pressure reactor, which is conducive to improving the reaction efficiency.

[0030] The high-pressure reactor 1 has a steam feed pipe 11, which is used to connect to an external steam source. The steam source is used to continuously supply high-temperature steam to the high-pressure reactor 1 to provide a main heating source for the slurry raw materials in the high-pressure reactor.

[0031] The embodiment shown in FIG1 includes three flash tanks 2, namely a first flash tank 21, a second flash tank 22, and a third flash tank 23. The autoclave 1, the first flash tank 21, the second flash tank 22, and the third flash tank 23 are connected in sequence, so that the slurry leached from the autoclave 1 passes through the first flash tank 21, the second flash tank 22, and the third flash tank 23 in sequence, and then enters the next processing step after being output from the third flash tank 23. The first flash tank 21, the second flash tank 22, and the third flash tank 23 can gradually release the pressure of the slurry leached from the autoclave 1, thereby preventing the flash tanks from being overly pressurized, which is beneficial for protecting each flash tank 23.

[0032] It is understandable that in other embodiments, the number of flash tanks 2 is not limited, for example, it can be two, four or more than four. The number of flash tanks 2 can be determined according to actual pressure release requirements and is not excessively limited here.

[0033] There are three preheating towers 3: a first preheating tower 31, a second preheating tower 32, and a third preheating tower 33. The autoclave 1, the first preheating tower 31, the second preheating tower 32, and the third preheating tower 33 are sequentially connected. Slurry feedstock is fed into the third preheating tower 33, passes through the third preheating tower 33, the second preheating tower 32, and the first preheating tower 31, before entering the autoclave 1. This sequential preheating of the slurry through the third preheating tower 33, the second preheating tower 32, and the first preheating tower 31 before entering the autoclave 1 improves reaction efficiency.

[0034] It can be understood that in other embodiments, the number of preheating towers 3 is not limited, for example, it can also be two, four or more than four. The more preheating towers 3 there are, the higher the heat of the material finally reaching the high-pressure reactor 1. The number of preheating towers 3 can be determined according to the actual preheating requirements and is not excessively limited here.

[0035] The first flash tank 21 is connected to the first preheating tower 31 via a steam pipe, allowing residual heat from the slurry after depressurization within the first flash tank 21 to be transferred to the first preheating tower 31, thereby heating the slurry flowing through the first preheating tower 31. Compared to other flash tanks, the first flash tank 21 releases the most heat after depressurization. The first preheating tower 31 is directly connected to the autoclave 1, allowing the heat released from the first flash tank 21 to be transferred directly to the autoclave 1 through the first preheating tower 31, minimizing heat loss during the transfer process.

[0036] The second flash tank 22 is connected to the second preheating tower 32 through a steam pipe, so that the residual heat of the slurry after pressure release in the second flash tank 22 can be transferred to the second preheating tower 32 to heat the slurry raw materials flowing through the second preheating tower 32.

[0037] The third flash tank 23 is connected to the third preheating tower 33 through a steam pipe, so that the residual heat of the slurry after pressure release in the third flash tank 23 can be transferred to the third preheating tower 33 to heat the slurry raw material flowing through the third preheating tower 33.

[0038] The structures of the first flash tank 21, the second flash tank 22 and the third flash tank 23 are the same. The structure of the flash tank 2 will be further described with the first flash tank 21 as a standard.

[0039] The first flash tank 21 includes a tank body 24 and an air outlet 25 , a feed port 26 and a discharge port 27 provided on the tank body 24 . The air outlet 25 and the feed port 26 are both located at the top of the tank body 24 , and the discharge port 27 is located at the side of the tank body 24 .

[0040] A pressure relief chamber 241 is provided in the tank body 24, and the air outlet 25, the feed port 26 and the discharge port 27 are all connected to the pressure relief chamber 241, and the air outlet 25, the feed port 26 and the discharge port 27 can be controlled by corresponding switches to open and close the air outside the tank body 24.

[0041] The tank body 24 is connected to the high-pressure reactor 1 through the feed port 26 . The high-pressure slurry leached from the high-pressure reactor 1 can be input into the pressure relief chamber 241 through the feed port 26 and fall from the top of the pressure relief chamber 241 to the bottom.

[0042] Tank body 24 is connected to second flash tank 22 via discharge port 27, allowing slurry from pressure relief chamber 241 to be fed into second flash tank 22 via discharge port 27 for further pressure relief. It should be noted that the discharge port of third flash tank 23 is used to connect to the next processing step, allowing slurry discharged from third flash tank 23 to enter the next processing step through the material port for further processing.

[0043] The tank body 24 is connected to the first preheating tower 31 through the air outlet 25 , so that the heat in the pressure release chamber 241 can be transferred to the first preheating tower 31 through the air outlet 25 .

[0044] The first flash tank 21 includes a buffer assembly 28 provided on the tank body 24. The buffer assembly 28 is located at the bottom of the pressure relief chamber 241 and is used to buffer the slurry falling from the feed port 26 to prevent the slurry from directly impacting the wall of the pressure relief chamber 241 and damaging the tank body 24.

[0045] The buffer assembly 28 includes a buffer member 281 and a connecting structure 282 , wherein one end of the connecting structure 282 is connected to the buffer member 281 , and the other end of the connecting structure 282 is connected to the bottom of the pressure release chamber 241 to fix the buffer member 281 .

[0046] The connecting structure 282 includes a first elastic frame 283, a second elastic frame 284 and a connecting piece 285, wherein the ends of the first elastic frame 283 and the second elastic frame 284 that are close to each other are connected by the connecting piece 285, the end of the first elastic frame 283 away from the second elastic frame 284 is connected to the buffer member 281, and the end of the second elastic frame 284 away from the first elastic frame 283 is connected to the bottom of the pressure relief chamber 241.

[0047] The first elastic frame 283 and the second elastic frame 284 are both V-shaped, and the tips of the first elastic frame 283 and the second elastic frame 284 are connected by a connector 285. The connector 285 can be a welded body, and the first elastic frame 283 and the second elastic frame 284 are connected by welding.

[0048] The first elastic frame 283 and the second elastic frame 284 are both made of elastic metal, so that when the buffer member 281 is impacted by the slurry, the impact force can be transmitted to the first elastic frame 283 and the second elastic frame 284. The first elastic frame 283 and the second elastic frame 284 can stably buffer the impact force transmitted from the buffer member 281 through elastic buffering.

[0049] It is understood that in other embodiments, the connection structure 282 may be composed solely of a spring, with both ends of the spring respectively connected to the buffer 281 and the bottom of the pressure relief chamber 241. When the buffer 281 is subjected to the force of the slurry, the force can be directly transmitted to the spring for buffering.

[0050] The center of the buffer 281 protrudes toward the feed port 26 to form a central protrusion 286. The central protrusion 286 is tapered, allowing slurry falling from the feed port 26 to slide along the surface of the central protrusion 286. The side of the central protrusion 286 facing away from the feed port 26 is connected to the first elastic bracket 283 to secure the buffer 281.

[0051] Buffer member 281 defines a buffer groove 287 surrounding central protrusion 286. As will be appreciated, buffer groove 287 is annular in shape. In the radial direction of pressure relief chamber 241, the surface of buffer groove 287 is curved, and one end of buffer groove 287 is connected to and tangent to the surface of central protrusion 286. This allows the slurry to flow more smoothly into buffer groove 287 after passing through the surface of central protrusion 286 and out through the other end of buffer groove 287. The other end of buffer groove 287 is tangent to the wall of pressure relief chamber 241. This minimizes impact on the wall of pressure relief chamber 241 after the slurry flows out of buffer groove 287, thus protecting the wall of pressure relief chamber 241.

[0052] In addition, after the slurry slides upward from the buffer trough 287, the slurry that slides out can contact the slurry that subsequently falls from the feed port 26, thereby offsetting part of the interaction force and reducing the impact force of the falling slurry on the buffer 281, which is beneficial to protecting the buffer 281.

[0053] In other embodiments, the top of the central protrusion 286 can also be set to a horizontal plane, and the buffer groove 287 can also be set not to be tangent to the central protrusion 286 and the pressure relief chamber 241. It is sufficient to only set the surface of the buffer groove 287 to an arc surface, which can also play a buffering role on the falling slurry.

[0054] The structures of the first preheating tower 31 , the second preheating tower 32 and the third preheating tower 33 are the same. The structure of the preheating tower 33 will be further described with the first preheating tower 31 as a standard.

[0055] The first preheating tower 31 includes a tower body 311 and a preheating chamber 312, a feed port 313, a discharge port 314, an air inlet 315, a sewage outlet 316, and a steam inlet 317 arranged in the tower body 311. Among them, the feed port 313 is arranged near the top of the tower body 311 so that the slurry raw material can fall into the preheating chamber 312 after entering the preheating chamber 312 through the feed port 313.

[0056] The feed port 313 , the discharge port 314 , the air inlet 315 , the sewage outlet 316 , and the steam inlet 317 are all connected to the preheating chamber 312 , and are each provided with a corresponding switch valve to control the opening and closing of the external air with the tower body 311 .

[0057] The feed port 313 is connected to the discharge port 314 of the second preheating tower 32, so that the slurry material in the second preheating tower 32 can enter the preheating chamber 312 through the feed port 313. It should be emphasized that the feed port of the third preheating tower 33 is used to input the slurry material, and the slurry material then enters the second preheating tower 32 through the discharge port of the third preheating tower 33.

[0058] The discharge port 314 is used to connect to the high-pressure reactor 1 so that the slurry material preheated in the preheating chamber 312 can enter the high-pressure reactor through the discharge port 314 .

[0059] The drain port 316 is used to discharge waste liquid in the preheating chamber 312 to clean the preheating chamber 312 .

[0060] The air inlet 315 is used to connect to the air outlet 25 of the first flash tank 21, so that the steam in the first flash tank 21 can be transmitted to the preheating chamber 312 through the air inlet 315, preheating the slurry material in the preheating chamber 312 and making full use of the heat energy.

[0061] The steam inlet 317 is connected to an external steam supply source. High-temperature steam generated by the steam supply source can be input into the preheating chamber 312 through the steam inlet 317 to preheat the slurry material in the preheating chamber 312. The steam supply source provides the primary heat source for preheating the slurry material, while steam from the first flash tank 21 generally provides auxiliary preheating.

[0062] The first preheating tower 31 includes a heat exchange component 34 disposed in the preheating chamber 312 . The heat exchange component 34 generates heat after being exposed to high-temperature steam, thereby heating the slurry material flowing through the heat exchange component 34 .

[0063] The air inlet 315 is located between the heat exchange component 34 and the bottom of the tower body 311. When the slurry material falls through the heat exchange component 34, the high-temperature steam entering from the air inlet 315 rises in the preheating chamber 312 and mixes with the falling slurry material to fully heat the slurry material.

[0064] The heat exchange assembly 34 includes a first heat exchanger 341, a second heat exchanger 342 and a connector 343. The connector 343 connects the first heat exchanger 341 and the second heat exchanger 342. The second heat exchanger 342 is connected to the cavity wall of the preheating cavity 312 to fix the heat exchange assembly 34.

[0065] There are multiple connectors 343, which are arranged around the circumference of the first heat exchanger 341. The two ends of each connector 343 are respectively connected to the edge of the first heat exchanger 341 and the edge of the second heat exchanger 342, so that the first heat exchanger 341 is connected to the second heat exchanger 342.

[0066] The first heat exchanger 341 and the second heat exchanger 342 are separated to form a flow port 344 , so that the slurry in the preheating chamber 312 can flow through the first heat exchanger 341 , the flow port 344 , and the second heat exchanger 342 in sequence and fall to the bottom of the preheating chamber 312 .

[0067] The first heat exchanger 341 and the second heat exchanger 342 are both conical. In the direction from the first heat exchanger 341 to the second heat exchanger 342, the cross-sectional area of ​​the first heat exchanger 341 increases, and the cross-sectional area of ​​the second heat exchanger 342 decreases. The cross section is a plane perpendicular to the central axis of the first heat exchanger 341.

[0068] The extension path of the first heat exchanger 341 intersects the edge of the second heat exchanger 342, allowing the slurry flowing from the outer surface of the first heat exchanger 341 to flow through the flow port 344 to the inner surface of the second heat exchanger 342. The second heat exchanger 342 is hollow with two open ends. After passing through the inner surface of the second heat exchanger 342, the slurry can fall downward to the bottom of the preheating chamber 312.

[0069] The embodiment shown in Figure 3 includes three heat exchange assemblies 34, spaced apart above and below the preheating chamber 312. As the slurry material falls, it sequentially passes through each heat exchange assembly 34. Each time it passes through a heat exchange assembly 34, it heats the slurry material. The more heat exchange assemblies 34 the slurry material passes through, the higher its heat output. In other embodiments, the number of heat exchange assemblies 34 can also be other numbers, such as two, four, or more, without limitation.

[0070] The present invention gradually releases the pressure of the high-pressure reactor 1 by providing a multi-stage flash tank. The buffer assembly 28 provided in the flash tank can buffer the downward-rushing slurry, preventing the slurry from directly impacting the bottom and sides of the flash tank, which is beneficial to protecting the flash tank.

[0071] The multi-stage preheating tower preheats the slurry layer by layer, ensuring a high temperature before entering the autoclave, which helps improve reaction efficiency. Excess heat from the flash tank during decompression is transferred to the preheating tower for heat recovery and reuse, saving energy.

[0072] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A laterite nickel ore leaching flash tank and preheater combined heat exchange system, characterized in that: include: High pressure reactor; A preheating tower connected to the feed inlet of the high-pressure reactor; A flash tank is connected to the discharge port of the high-pressure reactor, and the flash tank is also connected to the preheating tower through a steam pipe. A pressure relief chamber and a buffer assembly are provided in the flash tank; the buffer assembly includes a buffer member and a connecting structure, one side of the connecting structure is connected to the buffer member, and the other side of the connecting structure is connected to the bottom of the pressure relief chamber; the buffer member has a central protrusion on the side facing away from the connecting structure, and the buffer member is provided with a buffer groove around the central protrusion, and the buffer groove is recessed toward one side of the connecting structure, the highest point of the central protrusion is higher than the lowest point of the buffer groove, and the surface of the central protrusion is connected to the surface of the buffer groove, so that the fluid falling in the pressure relief chamber can pass through the surface of the central protrusion and slide out from one end of the buffer groove to the other end.

2. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 1, characterized in that: The central protrusion is conical, and the highest point of the central protrusion is higher than any position of the buffer groove.

3. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 2, characterized in that: The buffer groove is an arc-shaped groove, and one end of the buffer groove is tangent to the surface of the central protrusion.

4. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 3, characterized in that: One end of the buffer groove away from the central protrusion is tangent to the cavity wall of the pressure release cavity.

5. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to any one of claims 1 to 4, characterized in that: The connecting structure includes a first elastic frame, a second elastic frame and a connecting piece. The ends of the first elastic frame and the second elastic frame that are close to each other are connected through the connecting piece. The end of the first elastic frame away from the second elastic frame is connected to the buffer. The end of the second elastic frame away from the first elastic frame is connected to the bottom of the pressure relief chamber.

6. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 1, characterized in that: The preheating tower comprises a tower body and a heat exchange component arranged inside the tower body, and the heat exchange component is arranged on the inner wall of the tower body.

7. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 6, characterized in that: There are multiple heat exchange components, and the multiple heat exchange components are arranged in the tower body at intervals up and down.

8. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 6, characterized in that: The heat exchange assembly includes a first heat exchanger, a second heat exchanger and a connector, the connector connects the first heat exchanger and the second heat exchanger, the first heat exchanger and the second heat exchanger are spaced apart to form a flow port, and the fluid inside the tower body can flow through the first heat exchanger, the flow port and the second heat exchanger in sequence.

9. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 8, characterized in that: The first heat exchanger and the second heat exchanger are both conical. In the direction from the first heat exchanger to the second heat exchanger, the cross-sectional area of ​​the first heat exchanger increases, while the cross-sectional area of ​​the second heat exchanger decreases. The extension path of the first heat exchanger passes through the second heat exchanger.

10. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 6, characterized in that: The tower body has an air inlet, which is located between the heat exchange component and the bottom of the tower body. The air inlet is used to introduce steam into the interior of the tower body to mix the steam with the fluid flowing through the preheating element.

11. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 1, characterized in that: The number of the preheating towers is three, namely the first preheating tower, the second preheating tower and the third preheating tower, and the high-pressure reactor, the first preheating tower, the second preheating tower and the third preheating tower are connected in sequence; the number of the flash tanks is three, namely the first flash tank, the second flash tank and the third flash tank, and the high-pressure reactor, the first flash tank, the second flash tank and the third flash tank are connected in sequence.

12. The laterite nickel ore leaching flash tank and preheater combined heat exchange system according to claim 11, characterized in that: The first flash tank is connected to the first preheating tower via a steam pipe, the second flash tank is connected to the second preheating tower via a steam pipe, and the third flash tank is connected to the third preheating tower via a steam pipe.

Images