A system and method for controlling the amount of aluminum precipitation in a high-pressure acid leaching process of lateritic nickel ore

Abstract

The present application relates to a kind of laterite nickel ore high-pressure acid leaching process Al release quantity control system and process, system includes: autoclave, including kettle body, first adding pipe, second adding pipe and discharge pipe, post-processing equipment, post-processing equipment is connected with discharge pipe;And control device, including first valve, second valve, first pressure sensor, second pressure sensor, aluminum ion detection device and control unit;Process includes, according to the input amount of inhibitor or the input flow of accelerator for increasing in leaching solution aluminum ion concentration, when the pressure drop difference of discharge pipeline exceeds the set range, increase the input flow of inhibitor, for relieving pipeline scale;The present application can reduce production fluctuation, stabilize production, reduce production and maintenance cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nickel ore processing, and particularly relates to a system and method for controlling Al precipitation amount in high-pressure acid leaching of laterite nickel ore. BACKGROUND

[0002] Laterite nickel ore is a loose clay-like aggregate of nickel, iron, magnesium, cobalt, silicon, aluminum and other element oxides formed by long-term weathering, leaching, impregnation and alteration of nickel olivine-based rocks in tropical or subtropical regions. The iron element in it is in +3 valence state due to severe oxidation, so the overall appearance is reddish brown, hence the name laterite nickel ore. Unlike sulfide nickel ore, laterite nickel ore is a refractory type of oxidized ore that cannot be effectively enriched in nickel through beneficiation. Therefore, the common processing method is to extract nickel from laterite nickel ore through beneficiation, high-pressure acid leaching and extraction.

[0003] In the high-pressure leaching process of laterite nickel ore, the presence of aluminum elements will adversely affect production. Therefore, in the prior art, for example, patent CN107099679A discloses a method of adding sodium sulfate or potassium sulfate to inhibit aluminum leaching, and an inhibitor is added to inhibit aluminum leaching in the autoclave.

[0004] However, there are the following problems: actually, too high or too low aluminum content in the leaching solution will adversely affect production: too high aluminum leaching rate will consume a large amount of neutralizing agent and generate a large amount of slag in the subsequent pre-neutralization and iron and aluminum precipitation steps, causing greater production burden on the subsequent steps; too low aluminum leaching rate will cause a large amount of Al to hydrolyze mainly in the autoclave and discharge pipe, resulting in a large amount of fouling, which will increase the frequency of shutdown and fouling removal, thereby reducing production efficiency, so it is necessary to balance the leaching amount of aluminum elements. SUMMARY

[0005] Therefore, the present application provides a system and method for controlling Al precipitation amount in high-pressure acid leaching of laterite nickel ore, so that the aluminum leaching rate is always within an appropriate range, thereby stabilizing production and reducing costs.

[0006] To achieve the above purpose, the technical solution of the present application to solve the technical problem is to provide a system for controlling Al precipitation amount in high-pressure acid leaching of laterite nickel ore, comprising: an autoclave comprising a kettle body, a first adding pipe, a second adding pipe and a discharge pipe, a raw material inlet for adding raw materials being formed on the kettle body, the first adding pipe and the second adding pipe being respectively in communication with the kettle body for adding a promoter for promoting aluminum element hydrolysis and precipitation and an inhibitor for inhibiting aluminum element hydrolysis and precipitation into the kettle body respectively, the discharge pipe being in communication with the kettle body for discharging reactants in the kettle body;

[0007] a post-treatment device connected to the discharge pipe for treating the reactants;

[0008] and a control device, comprising a first valve, a second valve, a first pressure sensor, a second pressure sensor, an aluminum ion detection device and a control unit, the first valve is arranged on the first adding pipe and used for controlling the flow of the accelerator, the second valve is arranged on the second adding pipe and used for controlling the flow of the inhibitor, the first pressure sensor is arranged on the discharge pipe close to one end of the kettle body and used for detecting the pressure of the feed end of the discharge pipe, the second pressure sensor is arranged on the discharge pipe close to the post-processing equipment and used for detecting the pressure of the discharge end, the aluminum ion detection device is connected with the post-processing equipment and used for detecting the concentration of aluminum ions in the post-processing equipment, the control unit is connected with the first valve, the second valve, the first pressure sensor, the second pressure sensor and the aluminum ion detection device, the control unit receives the detection results of the first pressure sensor, the second pressure sensor and the aluminum ion detection device, and increases the flow of the accelerator or the inhibitor according to the pressure difference between the first pressure sensor and the second pressure sensor and the concentration of aluminum ions.

[0009] Further, the control unit is further used for driving the second valve to increase the opening degree until the detection result of the aluminum ion detection device falls within the set range when the detection result of the aluminum ion detection device is higher than the set range, and driving the first valve to increase the opening degree until the detection result of the aluminum ion detection device rises within the set range when the detection result of the aluminum ion detection device is lower than the set range.

[0010] Further, the control unit is further used for driving the second valve to increase the opening degree when the pressure difference between the first pressure sensor and the second pressure sensor exceeds the set range.

[0011] Further, the control device further comprises a warning device, the warning device is electrically connected with the control unit, and the control unit drives the warning device to send a warning information when it is determined that the pipeline scaling cannot be alleviated.

[0012] Further, the condition that the control unit determines that the pipeline scaling cannot be alleviated is that the pressure difference between the first pressure sensor and the second pressure sensor exceeds the set range and the opening degree of the second valve has reached the maximum.

[0013] Further, the accelerator is MgSO4, and the inhibitor is alunite.

[0014] Further, the post-stage processing device comprises a flash mechanism and a leaching solution storage tank, the flash mechanism is communicated with the discharge pipe, the leaching solution storage tank is communicated with the flash mechanism, and the aluminum ion detection device is connected with the leaching solution storage tank and used for detecting the aluminum ion concentration of the leaching solution in the leaching solution storage tank.

[0015] The application also provides a method for controlling Al precipitation in a high-pressure acid leaching process of laterite nickel ore, based on the Al precipitation control system for the high-pressure acid leaching process of laterite nickel ore, comprising the following steps:

[0016] The aluminum ion concentration in the leaching solution is collected to determine whether it is within the set range; if it is out of the set range, the addition flow of the inhibitor or the promoter is gradually increased until the aluminum ion concentration is within the set range.

[0017] The pressure drop difference of the discharge pipeline is collected to determine whether it is within the set range, and if it is out of the set range, the addition amount of the inhibitor is gradually increased.

[0018] Further, the collection of the aluminum ion concentration in the leaching solution and the determination of whether it is within the set range, and if it is out of the set range, the addition amount of the inhibitor or the promoter is gradually increased until the aluminum ion concentration is within the set range, comprises:

[0019] The aluminum ion concentration in the leaching solution is collected to determine whether it is within the set range;

[0020] If it is higher than the set range, the second valve is driven to increase the opening degree until the aluminum ion concentration falls within the set range;

[0021] If it is lower than the set range, the first valve is driven to increase the opening degree until the aluminum ion concentration increases to the set range.

[0022] Further, the collection of the pressure drop difference of the discharge pipeline and the determination of whether it is within the set range, and if it is out of the set range, the addition amount of the inhibitor is gradually increased, comprises:

[0023] The pressures at both ends of the discharge pipeline are collected to calculate the pressure difference between the two ends;

[0024] The pressure difference is compared with the set range;

[0025] If it is out of the set range, the second valve is driven to increase the opening degree.

[0026] Further, the following step is further included: when the pipeline scaling cannot be alleviated, a warning information is sent out.

[0027] Further, the condition for determining that the pipeline scaling cannot be alleviated is that the pressure difference between the two ends of the discharge pipeline is out of the set range and the pipeline valve for adding the inhibitor has been opened to the maximum.

[0028] Compared with the prior art, the red soil nickel ore high-pressure acid leaching process Al precipitation amount regulation system and method has the following beneficial effects:

[0029] The first valve, the second valve, the first pressure sensor, the second pressure sensor, the aluminum ion detection device and the regulation unit are arranged in the application, the pressure at both ends of the discharge pipe and the aluminum ion concentration in the post-treatment equipment can be detected, the opening degree of the first valve and the second valve can be controlled by the regulation unit according to the pressure difference at both ends of the discharge pipe and the aluminum ion concentration in the post-treatment equipment, the adding flow of the accelerant and the inhibitor is adjusted, the aluminum ion concentration in the leaching solution is stabilized in the set range, the fluctuation of the production process is effectively reduced, stable production is realized, and the production and maintenance costs are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A red soil nickel ore high-pressure acid leaching process Al precipitation amount regulation system provided by the application is shown in the figure.

[0031] In the figure: 1-high pressure kettle, 11-kettle body, 12-first adding pipe, 13-second adding pipe, 14-discharge pipe, 2-post-treatment equipment, 21-flash evaporation mechanism, 211-first stage flash evaporator, 212-second stage flash evaporator, 2133-third stage flash evaporator, 22-leaching solution storage tank, 3-regulation device, 31-first valve, 32-second valve, 33-first pressure sensor, 34-second pressure sensor, 35-aluminum ion detection device. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and do not limit the application.

[0033] Please refer to Figure 1The application provides an Al precipitation amount regulation system for a high-pressure acid leaching process of laterite nickel ore, which comprises a high-pressure kettle 1, a post-treatment device 2 and a regulation device 3, the high-pressure kettle 1 comprises a kettle body 11, a first adding pipe 12, a second adding pipe 13 and a discharge pipe 14, a raw material inlet for adding raw materials is formed in the kettle body 11, the first adding pipe 12 and the second adding pipe 13 are respectively communicated with the kettle body 11, and are used for adding a promoter for promoting the hydrolysis and precipitation of aluminum elements and an inhibitor for inhibiting the hydrolysis and precipitation of aluminum elements into the kettle body 11 respectively, the discharge pipe 14 is communicated with the kettle body 11 and is used for discharging reactants in the kettle body 11, the post-treatment device 2 is connected with the discharge pipe 14 and is used for treating the reactants, the regulation device 3 comprises a first valve 31, a second valve 32, a first pressure sensor 33, a second pressure sensor 34, an aluminum ion detection device 35 and a regulation unit, the first valve 31 is arranged on the first adding pipe 12, the second valve 32 is arranged on the second adding pipe 13, the first pressure sensor 33 is arranged in the interior of the discharge pipe 14 near one end of the kettle body 11, the second pressure sensor 34 is arranged in the interior of the discharge pipe 14 near the other end of the post-treatment device 2, the aluminum ion detection device 35 is connected with the post-treatment device 2 and is used for detecting the aluminum ion concentration in the post-treatment device 2, and the regulation unit is connected with the first valve 31, the second valve 32, the first pressure sensor 33, the second pressure sensor 34 and the aluminum ion detection device 35, receives the detection results of the first pressure sensor 33, the second pressure sensor 34 and the aluminum ion detection device 35 and increases the adding flow of the promoter or the inhibitor according to the comparison results of the pressure difference between the first pressure sensor 33 and the second pressure sensor 34 and the set range and the comparison results of the aluminum ion concentration and the set range.

[0034] The application is provided with the first valve 31, the second valve 32, the first pressure sensor 33, the second pressure sensor 34, the aluminum ion detection device 35 and the regulation unit, the pressure at both ends of the discharge pipe 14 and the aluminum ion concentration in the post-treatment device 2 can be detected, the regulation unit can control the opening degree of the first valve 31 and the second valve 32 according to the pressure difference between both ends of the discharge pipe 14 and the aluminum ion concentration in the post-treatment device 2, the adding flow of the promoter and the inhibitor can be adjusted, the aluminum ion concentration can be stabilized in the set range, the fluctuation in the production process is effectively reduced, stable production is realized, and the production and maintenance costs are reduced.

[0035] Specifically, a titanium infiltration layer is arranged on the inner wall of the kettle body 11, which can play an anticorrosion effect and prolong the service life.

[0036] Specifically, the raw material inlet includes a first inlet for adding ore slurry, a second inlet for adding sulfuric acid, and a third inlet for passing steam.

[0037] Specifically, the accelerator is MgSO4.

[0038] Specifically, the inhibitor is alunite.

[0039] Specifically, the post-treatment device 2 includes a flash mechanism 21 and a leaching solution storage tank 22, the flash mechanism 21 is in communication with the discharge pipe 14, the leaching solution storage tank 22 is in communication with the flash mechanism 21, and the aluminum ion detection device 35 is connected to the leaching solution storage tank 22 for detecting the aluminum ion concentration of the leaching solution in the leaching solution storage tank 22. The flash mechanism 21 is used for flash treatment of the ore slurry, and the leaching solution storage tank 22 is used for storing the leaching solution.

[0040] Further, the flash mechanism 21 includes a first flash evaporator 211, a second flash evaporator 212, and a third flash evaporator 213, which are connected in sequence, the first flash evaporator 211 is in communication with the discharge pipe 14, and the third flash evaporator 213 is connected to the leaching solution storage tank 22.

[0041] Further, the control unit is also used to drive the second valve 32 to increase the opening degree until the detection result of the aluminum ion detection device 35 falls within the set range when the detection result of the aluminum ion detection device 35 is higher than the set range, and drive the first valve 31 to increase the opening degree until the detection result of the aluminum ion detection device 35 rises within the set range when the detection result of the aluminum ion detection device 35 is lower than the set range.

[0042] Further, the control unit is also used to drive the second valve 32 to increase the opening degree when the pressure difference between the first pressure sensor 33 and the second pressure sensor 34 exceeds the set range.

[0043] Further, the control device further includes a warning device, the warning device is electrically connected to the control unit, and the control unit drives the warning device to issue a warning information when it is determined that the pipeline scaling cannot be alleviated.

[0044] Further, the condition that the control unit determines that the pipeline scaling cannot be alleviated is that the pressure difference between the first pressure sensor 33 and the second pressure sensor 34 exceeds the set range and the opening degree of the second valve 32 has reached the maximum.

[0045] The application also provides a method for controlling the Al precipitation amount in a high-pressure acid leaching process of laterite nickel ore, based on the Al precipitation amount control system for the high-pressure acid leaching process of laterite nickel ore, and the method comprises the following steps:

[0046] The concentration of aluminum ions in the leaching solution is collected to determine whether it is within the set range; if it is not, the flow rate of the inhibitor or the accelerator is gradually increased until the concentration of aluminum ions is within the set range.

[0047] The pressure drop difference of the discharge pipeline is collected to determine whether it is within the set range; if it is not, the flow rate of the inhibitor is gradually increased.

[0048] Further, the concentration of aluminum ions in the leaching solution is collected to determine whether it is within the set range; if it is not, the amount of the inhibitor or the accelerator is gradually increased until the concentration of aluminum ions is within the set range, which comprises:

[0049] The concentration of aluminum ions in the leaching solution is collected to determine whether it is within the set range;

[0050] If it is higher than the set range, the second valve is driven to increase the opening degree until the concentration of aluminum ions falls within the set range;

[0051] If it is lower than the set range, the first valve is driven to increase the opening degree until the concentration of aluminum ions increases to within the set range.

[0052] Further, the pressure drop difference of the discharge pipeline is collected to determine whether it is within the set range; if it is not, the amount of the inhibitor is gradually increased, which comprises:

[0053] The pressures at both ends of the discharge pipeline are collected to calculate the pressure difference between the two ends;

[0054] The pressure difference is compared with the set range;

[0055] If it is not within the set range, the second valve is driven to increase the opening degree.

[0056] Further, the method further comprises the following step: when the pipeline scaling cannot be alleviated, a shutdown and scaling removal reminder is sent.

[0057] Further, the condition for determining that the pipeline scaling cannot be alleviated is that the pressure difference between the two ends of the discharge pipeline is beyond the set range and the opening degree of the second valve has reached the maximum.

[0058] Experimental example

[0059] The concentration of aluminum ions in the leaching solution is greatly affected by the concentration of aluminum ions in the raw ore and the parameters of the high-pressure acid leaching process, and the concentration of aluminum ions in the leaching solution increases with the decrease of the concentration of aluminum ions in the raw ore and the leaching temperature. Therefore, in order to verify the effect of the present application, the concentration of aluminum ions in the leaching solution after treating the ore slurry with different concentrations of aluminum ions in the raw ore at different acid leaching temperatures before and after the implementation of the present application is recorded. For specific data, please see the following table:

[0060]

[0061] It can be seen that before the regulation, the concentration of aluminum ions in the leaching solution is greatly affected by the concentration of aluminum ions in the raw ore and the parameters of the high-pressure acid leaching process, and the fluctuation range of the concentration of aluminum ions in the leaching solution is large; after the implementation of the present application, no matter the concentration of aluminum ions in the raw ore and the acid leaching temperature change, the fluctuation range of the concentration of aluminum ions in the leaching solution is significantly reduced and maintained within a proper range, which is conducive to stable production, reduction of production cost and maintenance cost.

[0062] Compared with the prior art, the present application has the following advantages:

[0063] The present application is provided with a first valve 31, a second valve 32, a first pressure sensor 33, a second pressure sensor 34, an aluminum ion detection device 35 and a regulation unit, which can detect the pressure at both ends of the discharge pipe 14 and the concentration of aluminum ions in the post-treatment equipment 2, and the regulation unit can control the opening degree of the first valve 31 and the second valve 32 according to the pressure difference at both ends of the discharge pipe 14 and the concentration of aluminum ions in the post-treatment equipment 2, adjust the addition flow of the accelerant and the inhibitor, and stabilize the concentration of aluminum ions in the leaching solution within a set range, which effectively reduces the fluctuation of the production process, realizes stable production, and reduces production and maintenance costs.

[0064] The specific embodiments of the present application described above do not constitute a limitation on the scope of protection of the present application. Any various other corresponding changes and modifications made according to the technical concept of the present application shall be included in the scope of protection of the present application.

Claims

1. A system for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore, characterized in that, include: An autoclave includes a vessel body, a first addition pipe, a second addition pipe, and a discharge pipe. The vessel body has a raw material inlet for adding raw materials. The first addition pipe and the second addition pipe are respectively connected to the vessel body and are used to add an accelerator that promotes the hydrolysis and precipitation of aluminum and an inhibitor that inhibits the hydrolysis and precipitation of aluminum to the vessel body, respectively. The discharge pipe is connected to the vessel body and is used to discharge the reactants in the vessel body. A post-processing device, connected to the discharge pipe, is used to process the reactants; The system includes a first valve, a second valve, a first pressure sensor, a second pressure sensor, an aluminum ion detection device, and a control unit. The first valve is located on the first addition pipe and is used to control the addition flow rate of the accelerator. The second valve is located on the second addition pipe and is used to control the addition flow rate of the inhibitor. The first pressure sensor is located at the end of the discharge pipe near the reactor body and is used to detect the pressure at the inlet end of the discharge pipe. The second pressure sensor is located at the end of the discharge pipe near the downstream processing equipment and is used to detect the pressure at the outlet end of the discharge pipe. The aluminum ion detection device is connected to the downstream processing equipment and is used to detect the aluminum ion concentration in the downstream processing equipment. The control unit is connected to the first valve, the second valve, the first pressure sensor, the second pressure sensor, and the aluminum ion detection device. The control unit receives the detection results from the first pressure sensor, the second pressure sensor, and the aluminum ion detection device, and increases the addition flow rate of the accelerator or inhibitor according to the pressure difference between the first pressure sensor and the second pressure sensor and the aluminum ion concentration.

2. The Al precipitation control system for high-pressure acid leaching of laterite nickel ore as described in claim 1, characterized in that: The control unit is further configured to, when the detection result of the aluminum ion detection device is higher than the set range, drive the second valve to increase its opening degree until the detection result of the aluminum ion detection device falls back to the set range; and when the detection result of the aluminum ion detection device is lower than the set range, drive the first valve to increase its opening degree until the detection result of the aluminum ion detection device rises to the set range.

3. The Al precipitation control system for the high-pressure acid leaching process of laterite nickel ore as described in claim 1, characterized in that: The control unit is also used to drive the second valve to increase its opening degree when the pressure difference between the first pressure sensor and the second pressure sensor exceeds a set range.

4. The Al precipitation control system for high-pressure acid leaching of laterite nickel ore as described in claim 1, characterized in that: The control device also includes an early warning device, which is electrically connected to the control unit. When the control unit determines that the scaling in the pipeline cannot be relieved, it drives the early warning device to issue an early warning message.

5. The Al precipitation control system for high-pressure acid leaching of laterite nickel ore as described in claim 1, characterized in that: The control unit determines that the scaling in the pipeline cannot be alleviated when the pressure difference between the first pressure sensor and the second pressure sensor exceeds the set range and the second valve has reached its maximum opening degree.

6. The Al precipitation control system for high-pressure acid leaching of laterite nickel ore as described in claim 5, characterized in that: The accelerator is MgSO4, and the inhibitor is alunite.

7. The Al precipitation control system for high-pressure acid leaching of laterite nickel ore as described in claim 1, characterized in that: The post-processing equipment includes a flash evaporation mechanism and a leachate storage tank. The flash evaporation mechanism is connected to the discharge pipe, the leachate storage tank is connected to the flash evaporation mechanism, and the aluminum ion detection device is connected to the leachate storage tank to detect the aluminum ion concentration in the leachate in the leachate storage tank.

8. A method for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore, based on the Al precipitation control system for high-pressure acid leaching of laterite nickel ore according to any one of claims 1-7, characterized in that, Includes the following steps: Collect the aluminum ion concentration in the leachate and determine whether it is within the set range; if it exceeds the set range, gradually increase the flow rate of the inhibitor or accelerator until the aluminum ion concentration reaches the set range. The pressure drop difference in the discharge pipeline is collected to determine whether it is within the set range. If it exceeds the set range, the flow rate of the inhibitor is gradually increased.

9. The method for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore as described in claim 8, characterized in that, The process of collecting the aluminum ion concentration in the leachate and determining whether it is within a set range; if it exceeds the set range, the flow rate of the inhibitor or accelerator is gradually increased until the aluminum ion concentration reaches the set range, including: Collect the aluminum ion concentration in the leachate and determine whether it is within the set range; If the concentration is higher than the set range, the second valve will be driven to increase its opening degree until the aluminum ion concentration drops back to the set range. If the concentration is below the set range, the first valve is driven to increase its opening degree until the aluminum ion concentration increases to the set range.

10. The method for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore as described in claim 8, characterized in that, The pressure drop difference in the collection and discharge pipeline is used to determine whether it is within a set range. If it exceeds the set range, the amount of inhibitor added is gradually increased, including: Collect the pressure at both ends of the discharge pipe and calculate the pressure difference between the two ends; Compare the pressure difference with the set range; If the opening exceeds the set range, the second valve will be activated to increase its opening degree.

11. The method for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore as described in claim 8, characterized in that, It also includes the following steps: When it is determined that the scaling in the pipes cannot be alleviated, an early warning message will be issued.

12. The method for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore as described in claim 11, characterized in that, The conditions for determining that pipe scaling cannot be alleviated are: the pressure difference between the two ends of the discharge pipe exceeds the set range and the second valve is opened to its maximum extent.

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