High-pressure acid leaching system

Abstract

The present application relates to the technical field of high-pressure acid leaching. Provided is a high-pressure acid leaching system, comprising an autoclave, a preheater, a flash tank and an autoclave feed pump. The autoclave is connected to the flash tank, the flash tank is connected to the preheater to introduce a flash gas into the preheater, and the preheater is connected to the autoclave via the autoclave feed pump. High-pressure air is introduced into the autoclave and / or the flash tank. The introduction of the high-pressure air into the autoclave and / or the flash tank enables the flash gas and the high-pressure air to jointly enter the preheater, thereby increasing the internal pressure of the preheater and reducing the temperature of ore slurry at an outlet of the preheater, and thus avoiding or reducing the occurrence of cavitation.

Description

[0001] The present application claims priority to Chinese patent application No. 202411445772.6, filed with the China National Intellectual Property Administration on October 16, 2024, and entitled with “HIGH-PRESSURE ACID LEACHING SYSTEM”, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of high-pressure acid leaching and, in particular, to a high-pressure acid leaching system. BACKGROUND

[0003] In recent years, the demand for nickel in industrial production has been increasing day by day. A high-pressure acid leaching process of the laterite nickel ore is a mainstream process for extracting nickel from the mineral in recent years. In the current operating methods, due to the fact that the mineral slurry in the preheater, flash vessel, and autoclave operates in a state close to the saturated vapor pressure, the pumps and valves in the system operate under harsh conditions, which can easily cause phenomena such as cavitation to affect their service life, and increase the maintenance cost of the system.

[0004] CN117083397A discloses a system and method for regulating and controlling an amount of Al precipitation during high-pressure acid leaching of the laterite nickel ore. The system includes an autoclave and post-treatment equipment. The autoclave includes an autoclave body, a first addition pipe, a second addition pipe, and a discharge pipe. The post-treatment equipment is connected to a discharge pipe. The post-treatment equipment includes a flash mechanism and a leachate storage vessel. The flash mechanism is communicated with the discharge pipe, and the 2025204741   28 Jan 2026 leachate storage vessel is communicated with the flash mechanism. Further, the flash mechanism includes a first stage flash vessel, a second stage flash vessel, and a third stage flash vessel. The first stage flash vessel, the second stage flash vessel, and the third stage flash vessel are connected in sequence, and the first stage flash vessel is communicated with the discharge pipe.

[0005] The system for regulating and controlling the amount of Al precipitation during high-pressure acid leaching of the laterite nickel ore disclosed in the abovementioned invention application disclosed the autoclave and a multi-stage flash mechanism connected thereto, but it did not disclose a structure for recovering and utilizing a flash gas generated by the multi-stage flash mechanism, and a related improvement solution. SUMMARY

[0006] The present application is made in view of the state of the prior art mentioned above. In certain embodiments, the present application provides a high-pressure acid leaching system, which can at least partially introduce the flash gas generated by the first stage flash vessel into a final stage preheater to heat the mineral slurry, and at the same time can introduce high-pressure air into the autoclave and / or flash vessel to reduce the occurrence of cavitation and improve the service life of a feed pump of the autoclave.

[0007] The present application provides a high-pressure acid leaching system, which includes: an autoclave, a preheater, a flash vessel, and an autoclave feed pump, where, the autoclave is connected to the flash vessel, the flash vessel is connected to the preheater to introduce a flash gas into the preheater, the preheater is connected to the autoclave via the autoclave feed pump, and high-pressure air is introduced into the autoclave and / or the flash vessel.

[0008] In at least one possible implementation, the high-pressure acid leaching system includes a first flow control mechanism for regulating a flow of the high-pressure air introducing into the autoclave, and the first flow control mechanism is configured to control the flow of the high-pressure air based on a difference relationship between an internal pressure of the autoclave and a valve inlet pressure of the flash vessel.

[0009] In at least one possible implementation, the first flow control mechanism is configured such that: multiple consecutive different difference relationships correspond to the same flow, which flow corresponds to a maximum value among the multiple consecutive different difference relationships; or each different difference relationship corresponds to a different flow.

[0010] In at least one possible implementation, the autoclave includes a first exhaust valve, the first flow control mechanism calculates a theoretical pressure inside the autoclave based on states of the internal pressure of the autoclave and the valve inlet pressure of the flash vessel, and controls an opening degree of the first exhaust valve and / or the flow of the high-pressure air introduced into the autoclave based on a numerical relationship between the theoretical pressure inside the autoclave and a measured actual pressure inside the autoclave.

[0011] In at least one possible implementation, the theoretical pressure inside the autoclave is obtained by a sum of a difference between the internal pressure of the autoclave and the valve inlet pressure of the flash vessel and a saturated vapor pressure corresponding to a temperature of the autoclave.

[0012] In at least one possible implementation, the numerical relationship comprises a difference relationship and / or a ratio relationship.

[0013] In at least one possible implementation, a second flow control mechanism is included to regulate a flow of the high-pressure air introduced into the flash vessel, the second flow control mechanism is configured to control the flow of the high-pressure air introduced into the flash vessel within a preset range.

[0014] In at least one possible implementation, the flash vessel includes a second exhaust valve, and a theoretical pressure inside the flash vessel is calculated based on the preset range, the second flow control mechanism controls an opening degree of the second exhaust valve and / or the flow of the high-pressure air introduced into the flash vessel based on a numerical relationship between the theoretical pressure inside the flash vessel and a measured actual pressure inside the flash vessel.

[0015] In at least one possible implementation, the theoretical pressure inside the flash vessel is obtained by a sum of a saturated vapor pressure corresponding to a temperature of the flash vessel and a pressures corresponding to the preset range.

[0016] In at least one possible implementation, a gas regulation and control system is included, and the gas regulation and control system is configured to adjust an amount of the flash gas of the flash vessel entering the preheater according to the temperature of the preheater.

[0017] In at least one possible implementation, the preheater includes at least a first stage preheater, a second stage preheater, and a final stage preheater that sequentially increase in temperature, the flash vessel includes at least a first stage flash vessel, a second stage flash vessel, and a third stage flash vessel that sequentially decrease in pressure, and the second stage flash vessel is connected to the second stage preheater, the third stage flash vessel is connected to the first stage preheater, and the first stage flash vessel is connected to the final stage preheater.

[0018] The high-pressure acid leaching system provided in the present application can separately introduce the high-pressure air into the autoclave and / or the flash vessel, so that both the flash gas and high-pressure air can enter the preheater to increase the pressure inside the preheater (especially the final stage preheater) and reduce a mineral slurry temperature at an outlet of the preheater. Furthermore, it can avoid or reduce the occurrence of cavitation, extend the service life of the autoclave feed pump, enable the equipment to operate stably for a long time, and reduce the operation and maintenance cost of the high-pressure acid leaching system. BRIEF DESCRIPTION OF DRAWINGS

[0019] FIG. 1 shows a schematic structural diagram of a high-pressure acid leaching system according to an embodiment of the present application.

[0020] Description of reference numbers: 10-Autoclave, 21-First stage preheater, 22-Second stage preheater, 23-Third stage preheater, 31-First stage flash vessel, 32-Second stage flash vessel, 33-Third stage flash vessel, 41-First stage feed pump, 42-Second stage feed pump, 43-Third stage feed pump, 44-Autoclave feed pump. DESCRIPTION OF EMBODIMENTS

[0021] The exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific explanations are only intended to teach the person skilled in the art how to implement the present application, and are neither intended to exhaust all feasible ways of the present application, nor to limit the scope of the present application.

[0022] An embodiment of the present application provides a high-pressure acid leaching system, which may include an autoclave 10, a final stage preheater, a first stage flash vessel, and an autoclave feed pump 44. Preferably, the high-pressure acid leaching system can include multi-stage preheaters, multi-stage flash vessels, and multi-stage feed pumps to achieve stepwise heating and flashing of the mineral slurry, thereby improving the efficiency and benefits of mineral slurry treatment. The high-pressure acid leaching system provided in the present embodiment can be applied to a high-pressure acid leaching production process of the laterite nickel ore. It can be understood that the application scenario of the high-pressure acid leaching system is not limited to this. The connection referred to in the present application includes direct connections, as well as indirect connections through structures such as pipelines, valves etc.

[0023] Specifically, the multi-stage preheaters may include a final stage preheater connected to the autoclave 10 via a pump, a valve, etc. Exemplarily, the multi-stage preheaters can be three-stage preheaters, namely, a first stage preheater 21, a second stage preheater 22, and a third stage preheater 23 (it can be understood that the third stage preheater is the final stage preheater in the present example), and working temperatures of the multi-stage preheaters can be increased in sequence. The multi-stage flash vessels can include three-stage flash vessels, namely, a first stage flash vessel 31, a second stage flash vessel 32, and a third stage flash vessel 33. Vapor pressures of the first stage flash vessel 31, the second stage flash vessel 32, and the third stage flash vessel 33 can be reduced in sequence, that is, the first stage flash vessel 31 can be a high-pressure flash vessel, the second stage flash vessel 32 can be a medium-pressure flash vessel, and the third stage flash vessel 33 can be a low-pressure flash vessel (flashing: after high-pressure saturated water enters a relatively low-pressure container, due to a sudden decrease in pressure, a part of the saturated water becomes saturated water vapor and saturated water at a pressure of the container). The multi-stage feed pumps may include three-stage feed pumps (namely, a first stage feed pump 41, a second stage feed pump 42, and a third stage feed pump 43), and an autoclave feed pump 44. The first stage feed pump 41, the second stage feed pump 42, the third stage feed pump 43, and the autoclave feed pump 44 can be installed upstream of the first stage preheater 21, the second stage preheater 22, the third stage preheater 23, and the autoclave 10, respectively.

[0024] It can be understood that the high-pressure acid leaching system can also include a pipeline system, a valve system, and a regulation and control system.

[0025] The first stage preheater 21, the second stage preheater 22, and the third stage preheater 23 can be connected in sequence (indirect connection through a pump and a pipelines), and the material (mineral slurry) can enter the first stage preheater 21, and then enter the autoclave 10 after passing through the first stage preheater 21, the second stage preheater 22, and the third stage preheater 23 in sequence. The autoclave 10 can be connected to the first stage flash vessel 31. The material (mineral slurry) processed in the autoclave 10 can be discharged into the first stage flash vessel 31 through a discharge pipe, and then enter downstream production equipment after passing through the first stage flash vessel 31, the second stage flash vessel 32, and the third stage flash vessel 33 in sequence. The first stage flash vessel 31 serves as a flash vessel into which the mineral slurry is first introduced. The temperature of the mineral slurry gradually decreases, and the temperature of the flash gas generated in the first stage flash vessel is higher than that of the flash gas generated in the subsequent connected flash vessels (the second stage flash vessel, and the third stage flash vessel). A pressure reducing valve can be provided upstream of each flash vessel to relatively reduce the pressure inside the flash vessel.

[0026] The gas generated in the multi-stage flash vessels can be separately introduced into the multi-stage preheaters so as to use the flash gas (saturated vapor) to stepwise heat the material. To achieve a gradual increase in temperature of the material, the preheating temperature of the multi-stage preheaters also needs to be gradually increased correspondingly, that is, the temperature of the final stage preheater (three stage preheater) is higher than the preheating temperature of the preheaters (the first stage preheater and the second stage preheater) connected in front of the final stage preheater. Further, the final stage preheater can be connected to the first stage flash vessel, and the primary preheater can be connected to the final stage flash vessel to match the temperatures of the multi-stage flash vessels with those of the multi-stage preheaters. Specifically, as shown in FIG. 1, the mineral slurry (exemplarily, it can be formed by adding water and other auxiliary materials to a laterite nickel ore raw material) can be transported to the first stage preheater 21 through the first stage feed pump 41, and the vapor in the third stage flash vessel 33 can be transported to the first stage preheater 21. The vapor from the third stage flash vessel 33 can heat the mineral slurry in the first stage preheater 21. Exemplarily, the mineral slurry can be heated from room temperature to 95°C to 100C. The mineral slurry in the first stage preheater 21 can be transported to the second stage preheater 22 through the second stage feed pump 42, and the vapor in the second stage flash vessel 32 can be transported to the second stage preheater 22. The vapor from the second stage flash vessel 32 can further heat the mineral slurry in the second stage preheater 22. Exemplarily, the mineral slurry can be heated to 150C to 155C. The mineral slurry in the second stage preheater 22 can be transported to the third stage preheater 23 through the third stage feed pump 43, and the vapor in the first stage flash vessel 31 can be transported to the third stage preheater 23. The vapor from the first stage flash vessel 31 can further heat the mineral slurry in the third stage preheater 23. Exemplarily, the mineral slurry can be heated to 200OC to 205°C. It can be understood that the connection structures and working processes of the above-mentioned multi-stage flash vessels, the above-mentioned multi-stage feed pumps, and the above-mentioned multi-stage preheaters can meet the heating requirements of the mineral slurry and the effective recovery and utilization requirements of thermal energy in high-pressure acid leaching process.

[0027] The mineral slurry heated by the three stage preheater 23 can be pumped into the autoclave 10 through the autoclave feed pump 44. Concentrated sulfuric acid and vapor (high-pressure vapor) can be added to the autoclave 10 in a certain ratio (such as an appropriate acid-ore ratio, i.e., a mass ratio of dry weight of the mineral slurry and the acid), and the temperature of the mineral slurry can be raised to 245°C to 255OC by the heat generated during dilution using concentrated sulfuric acid and vapor. In an experimental example, in the mineral slurry inside the autoclave, a leaching rate of nickel was greater than 95%, a leaching rate of cobalt was greater than 92%, and most of impurities such as iron, silicon, aluminum, etc. remained in the slag.

[0028] It can be understood that the first stage preheater 21, the second stage preheater 22, the third stage preheater 23, the autoclave 10, and the first stage flash vessel 31 are all provided with a tail gas discharge structure (such as tail gas discharge pipe) to discharge the tail gas generated during the production process.

[0029] Preferably, the first stage feed pump 41, the second stage feed pump 42, and the third stage feed pump 43 can be a centrifugal pump.

[0030] Preferably, the autoclave feed pump 44 can be a diaphragm pump, especially a one-way valve diaphragm pump. It can be understood that the diaphragm pump has a simple structure, low cost, and good corrosion resistance, and thus is suitable for use in the transportation process of the mineral slurry.

[0031] The high-pressure acid leaching system of the present embodiment can introduce the high-pressure air into the autoclave 10. It can be understood that introducing high-pressure air into the autoclave 10 can increase the pressure inside the autoclave 10 and avoid or reduce the occurrence of flashing of the mineral slurry in the autoclave and the discharge pipe in advance (before entering the flash vessel).

[0032] The high-pressure acid leaching system of the present embodiment can also introduce the high-pressure air into the multi-stage flash vessels, especially into the first stage flash vessel 31. It can be understood that when the flash gas generated by the first stage flash vessel 31 is introduced into only the final stage preheater (the third stage preheater), the mineral slurry in the final stage preheater is close to or in a saturated vapor pressure state. Introduction of the high-pressure air into the first stage flash vessel 31 may allow the gas transported from the first stage flash vessel 31 to the third stage preheater 23 to include the flash gas and the high-pressure air (high-pressure air at room temperature), which can increase the pressure inside the third stage preheater 23 to a certain extent and reduce heat exchange efficiency between the first stage flash vessel 31 and the third stage preheater 23 (i.e., reducing the effect of the flash gas on raising the temperature of the mineral slurry to a certain extent). The above technical solution of introducing the high-pressure air into the first stage flash vessel 31 can further make the temperature of the mineral slurry at an outlet of the third stage preheater lower than its saturated temperature (under the working pressure of the third stage preheater), thereby making the autoclave feed pump (especially when it is a diaphragm pump) less prone to (avoid or reduce) cavitation and other phenomena when the mineral slurry enters the autoclave through the autoclave feed pump 44, so as to reduce the loss of the autoclave feed pump and improve theservice life of the autoclave feed pump. The solution of introducing the high-pressure air into the first stage flash vessel 31 can significantly improve the working environment of the autoclave feed pump 44 and the valve in the high-pressure acid leaching system, increase the service life of the autoclave feed pump and the valve, reduce the frequency of equipment maintenance and replacement, and improve economic efficiency. It can be understood that, due to the communication between the autoclave and the first stage flash vessel, even if the high-pressure air is introduced into only the autoclave 10, the high-pressure air can indirectly enter the first stage flash vessel, which can also achieve the above technical effects.

[0033] During the operation of the high-pressure acid leaching system, the high-pressure air can be continuously introduced into the autoclave and / or the flash vessel, and maintain relative stability of content and pressure of the high-pressure air within the high-pressure acid leaching system.

[0034] Preferably, the pressure inside the autoclave after introducing the high-pressure air can be 5 to 5.5 MPa (megapascal). The pressure of the high-pressure air introducing into the autoclave can be greater than the pressure inside the autoclave 10, so that the high-pressure air can smoothly enter the autoclave 10. The pressure inside the flash vessel after introducing the high-pressure air can be 2 to 2.2 MPa. The pressure of the high-pressure air introducing into the flash vessel (the first stage flash vessel) can be greater than the pressure inside the flash vessel, so that the high-pressure air can be smoothly introduced into the flash vessel. The temperature of the high-pressure air introducing into the autoclave and the flash vessel can be at room temperature. It can be understood that, under the pressure and temperature conditions, the beneficial effect brought by introducing the high-pressure air into the high-pressure acid leaching system can be effectively achieved.

[0035] It can be understood that the functions and roles of the high-pressure air introduced in the present embodiment are different from those of the vapor (high-pressure vapor) introduced into the autoclave. The high-pressure air and the vapor can be simultaneously or separately introduced into the autoclave.

[0036] The regulation and control system of the high-pressure acid leaching system in the present embodiment may include a gas regulation and control system, the gas regulation and control system may include a valve, as well as a temperature sensor and a pressure sensor. The valve can regulate the pressure, flow, etc. of the high-pressure air. The temperature sensor and the pressure sensor can monitor the temperature and the pressure during transportation of the high-pressure air. The gas regulation and control system can control the amount of flash gas generated by the multi-stage flash vessels and / or the amount of the introduced high-pressure air entering into the multi-stage preheaters. The flash gas generated by the multi-stage flash vessels can be partially or completely (i.e., at least partially) introduced into the multi-stage preheaters, and the gas regulation and control system can control the amount of the flash gas introduced into the multi-stage preheaters according to an actual production requirement. It can be understood that the gas regulation and control system can avoid that the amount of the flash gas (heat carried by the flash gas) introducing into the multi-stage preheaters is much larger than the amount of the flash gas (heat) required by the multi-stage preheaters, thereby avoid that the mineral slurry at the outlet of the three stage preheater approaches a saturated state (saturated vapor pressure state).

[0037] The gas regulation and control system can be configured to adjust the amount of the flash gas entering a preheater (including one or more preheaters) from a flash vessel (including one or more flash vessels) based on the temperature of the preheater, thereby achieving dynamic regulation and control of the temperature inside the preheater. Especially, the gas regulation and control system can be configured to regulate, based on the temperature of each preheater, the amount of the gas entering the preheater from the flash vessel connected to the preheater.

[0038] The high-pressure acid leaching system may also include a first flow control mechanism, which can be used to regulate the flow of the high-pressure air introducing into the autoclave 10. Further, the first flow control mechanism can be configured to control the flow of the high-pressure air based on a difference relationship between an internal pressure of the autoclave 10 and a valve inlet pressure of the flash vessel (the first stage flash vessel). Here, the valve inlet pressure refers to a pressure value measured at a valve located upstream of the flash vessel. Specifically, the valve inlet pressure of the flash vessel is a pressure obtained by subtracting a pipeline loss pressure from the internal pressure of the autoclave, that is, the difference between the internal pressure of the autoclave 10 and the valve inlet pressure of the flash vessel (the first stage flash vessel) is the pipeline loss pressure. The difference relationship can include a relative magnitude relationship of numerical values, a numerical difference relationship, a multiple relationship, etc. In other words, the flow of the high-pressure air can be controlled based on the relative magnitude, difference interval, multiple interval, etc. of the difference between the internal pressure of the autoclave 10 and the valve inlet pressure of the flash vessel (the first stage flash vessel).

[0039] The first flow control mechanism may be further configured such that: multiple consecutive different difference relationships correspond to the same flow, which flow corresponds to a maximum value among the multiple consecutive different difference relationships. That is, when the difference relationship is within a certain range, the flow of the high-pressure air is the same. Or each different difference relationship corresponds to a different flow. That is, the first flow control mechanism can flexibly regulate and control the flow of the high-pressure air through various methods.

[0040] The autoclave may also include a first exhaust valve, and a theoretical pressure inside the autoclave may be calculated based on states of the internal pressure of the autoclave 10 and the valve inlet pressure of the flash vessel. And then an opening degree of the first exhaust valve and / or the flow of the high-pressure air introduced into the autoclave 10 are controlled based on a numerical relationship between the theoretical pressure inside the autoclave and a measured actual pressure inside the autoclave (for example, measured by a pressure gauge). Through this method, secondary control of the flow of the high-pressure air can be achieved, further improving regulation and control precision of the pressure inside the autoclave. Here, the numerical relationship can include a difference relationship, a ratio relationship, etc.

[0041] A specific method for the theoretical pressure inside the autoclave can be calculating a sum of a difference between the internal pressure of the autoclave 10 and the valve inlet pressure of the flash vessel plus a saturated vapor pressure corresponding to the temperature of the autoclave 10. Exemplarily, based on practical experience, the theoretical pressure inside the autoclave is P=Psaturated in autoclave+0.6Mpa.

[0042] The high-pressure acid leaching system may also include a second flow control mechanism, the second flow control mechanism may be used to control flow of the high-pressure air introduced into the flash vessel, and configured to control the flow of the high-pressure air introduced into the flash vessel to be within a preset range, in order to maintain a stable flow of the high-pressure air introduced into the flash vessel.

[0043] The flash vessel (especially the first stage flash vessel) may include a second exhaust valve. The second flow control mechanism may control an opening degree of the second exhaust valve and / or the flow of the high-pressure air introduced into the flash vessel based on a numerical relationship between a theoretical pressure inside the flash vessel and a measured actual pressure inside the flash vessel (for example, measured by a pressure gauge). The theoretical pressure inside the flash vessel may be obtained by a sum of a saturated vapor pressure corresponding to a temperature of the flash vessel (the first stage flash vessel) and a preset range of the flow of the high-pressure air. Exemplarily, based on practical experience, the theoretical pressure inside the flash vessel is P=Psaturated in flash vessel+0.1~0.2Mpa.

[0044] The first flow control mechanism and the second flow control mechanism may include a valve, a pressure gauge, a flow meter, and a control unit. Further, the gas regulation and control mechanism and the second flow control mechanism can share some structures, especially some structures inside the flash vessel (the first stage flash vessel). Exemplarily, the gas regulation and control mechanism and the second flow control mechanism can share the pressure gauge inside the flash vessel.

[0045] An embodiment of the present application also provides a working method of a high-pressure acid leaching system, and the working method can be implemented using the above-mentioned high-pressure acid leaching system. The working method of the high-pressure acid leaching system mainly includes introducing a flash gas generated in a flash vessel into a preheater for preheating a mineral material, adding a preheated mineral slurry into an autoclave, introducing the mineral slurry in the autoclave into a flash vessel (the first stage flash vessel) for flashing, and introducing a high-pressure air into the autoclave and flash vessel (the first stage flash vessel), respectively. The some specific contents and technical effects of this working method have been explained in detail in the description of the high-pressure acid leaching system mentioned above, and will not be repeated here.

[0046] Below is a brief explanation of a part of the beneficial effects of the above embodiment of the present application.

[0047] The present application proposes a high-pressure acid leaching system, which can at least partially introduce a flash gas generated by multi-stage flash vessels into a preheater to preheat a mineral slurry, and can control a reasonable introduced amount of the flash gas through a gas regulation and control system. The present application can separately introduce the high-pressure air into the autoclave and the flash vessel, to reduce the occurrence of cavitation, extend the service life of the autoclave feed pump and the valve, enable the equipment to operate stably for a long time, and reduce the operation and maintenance cost of the high-pressure acid leaching system.

[0048] It can be understood that in the present application, when the number of a component or part is not specifically limited, the number thereof can be one or multiple, and the “multiple” herein refers to two or more. For the case where the drawings show and / or the specification describes the number of the component or part is a specific number, for example, two, three, or four, the specific number is usually exemplary rather than restrictive, and it can be understood as multiple, i.e., two or more, but this does not mean that the present application excludes the case where the number of the component or part is one.

[0049] It should be understood that the above embodiments are exemplary only and are not intended to limit the present application. A person skilled in the art can make various modifications and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application.

[0050] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any skilled person familiar with the technical field can easily think of changes or substitutions within the 2025204741   28 Jan 2026 technical scope disclosed in the present invention, and these changes or substitutions should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0051] Throughout this specification and the claims that follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0052] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims

1. A high-pressure acid leaching system, comprising an autoclave, a preheater, a flash vessel, and an autoclave feed pump, whereinthe autoclave is connected to the flash vessel, the flash vessel is connected to the preheater to introduce a flash gas into the preheater, and the preheater is connected to the autoclave via the autoclave feed pump, anda high-pressure air is introduced into the autoclave via a high pressure air inlet of the autoclave, the high-pressure acid leaching system comprises a first flow control mechanism for regulating a flow of the high-pressure air introducing into the autoclave, wherein the first flow control mechanism is configured to control the flow of the high-pressure air based on a difference relationship between an internal pressure of the autoclave and a valve inlet pressure of the flash vessel; and / or a high-pressure air is introduced into the flash vessel via a high pressure air inlet of the flash vessel, the high-pressure acid leaching system further comprises a second flow control mechanism for regulating a flow of the high-pressure air introduced into the flash vessel, wherein the second flow control mechanism is configured to control the flow of the high-pressure air introduced into the flash vessel to be within a preset range.

2. The high-pressure acid leaching system according to claim 1, wherein the first flow control mechanism is configured such that:multiple consecutive different difference relationships correspond to the same flow, which flow corresponds to a maximum value among the multiple consecutive different difference relationships; oreach different difference relationship corresponds to a different flow, wherein the difference relationship represents a difference between an internal pressure of the autoclave and a valve inlet pressure of the flash vessel.

3. The high-pressure acid leaching system according to claim 2, wherein the autoclave comprises a first exhaust valve, and2025204741   28 Jan 2026the first flow control mechanism calculates a theoretical pressure inside the autoclave based on states of the internal pressure of the autoclave and the valve inlet pressure of the flash vessel, and controls an opening degree of the first exhaust valve and / or the flow of the high-pressure air introduced into the autoclave based on a numerical relationship between the theoretical pressure inside the autoclave and a measured actual pressure inside the autoclave.

4. The high-pressure acid leaching system according to claim 3, wherein the theoretical pressure inside the autoclave is a sum of a difference between the internal pressure of the autoclave and the valve inlet pressure of the flash vessel, and a saturated vapor pressure corresponding to a temperature of the autoclave.

5. The high-pressure acid leaching system according to claim 3, wherein the numerical relationship comprises a difference relationship and / or a ratio relationship.

6. The high-pressure acid leaching system according to any one of claims 1 to 5, wherein the flash vessel comprises a second exhaust valve, and a theoretical pressure inside the flash vessel is calculated based on the preset range, andthe second flow control mechanism controls an opening degree of the second exhaust valve and / or the flow of the high-pressure air introduced into the flash vessel based on a numerical relationship between the theoretical pressure inside the flash vessel and a measured actual pressure inside the flash vessel.

7. The high-pressure acid leaching system according to claim 6, wherein the theoretical pressure inside the flash vessel is a sum of a saturated vapor pressure corresponding to a temperature of the flash vessel and a pressure corresponding to the preset range.

8. The high-pressure acid leaching system according to any one of claims 1 to 7, comprising a gas regulation and control system, wherein the gas regulation and control system is configured to adjust an amount of the flash gas of the flash vessel entering the preheater according to a temperature of the preheater.

9. The high-pressure acid leaching system according to any one of claims 1 to 8, wherein,2025204741   28 Jan 2026the preheater comprises at least a first stage preheater, a second stage preheater, and a final stage preheater that sequentially increase in temperature, the flash vessel comprises at least a first stage flash vessel, a second stage flash vessel, and a third stage flash vessel that sequentially decrease in pressure, andthe second stage flash vessel is connected to the second stage preheater, the third stage flash vessel is connected to the first stage preheater, and the first stage flash vessel is connected to the final stage preheater.

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