Method for dynamically regulating conditions of high-pressure leaching reaction of laterite nickel ore

Abstract

A method for dynamically regulating conditions of a high-pressure leaching reaction of a laterite nickel ore, comprising: setting a target temperature and target pressure of an autoclave; obtaining thermal power required for heating fed ore pulp to the target temperature; obtaining thermal power brought by fed acid; obtaining required new steam thermal power; obtaining the required flow of new steam; adjusting the real-time flow of the new steam to the required flow of the new steam, and adjusting the opening degree of an exhaust valve and the discharging flow of the autoclave, so that the real-time pressure of the autoclave is equal to the target pressure; and adjusting the flow of the new steam, so that the real-time temperature of the autoclave is equal to the target temperature. The method has the beneficial effect that: reaction conditions of a high-pressure leaching reaction are preliminarily determined on the basis of a feeding status, and then reaction control conditions are adjusted on the basis of the feedback of the real-time temperature and real-time pressure in the autoclave; and by combining the described two regulation modes, the temperature and the pressure in the autoclave can be maintained at an optimal temperature and optimal pressure, thereby improving the laterite nickel ore leaching efficiency.

Description

Dynamic control method for high-pressure leaching reaction conditions of laterite nickel ore Technical Field

[0001] The invention relates to the technical field of high-pressure leaching of laterite nickel ore, and in particular to a dynamic control method for high-pressure leaching reaction conditions of laterite nickel ore. Background Art

[0002] The high-pressure acid leaching process of laterite nickel ore is to acid-leach the ore pulp and strong acid solution in a high-temperature, high-pressure autoclave. Under the conditions of high temperature and strong acid, the selective leaching of nickel and cobalt is achieved, and most of the impurities of iron and aluminum are stored in the slag, thereby ensuring the recovery of valuable metals and reducing material consumption. The recovery rate of nickel and cobalt metals can reach 90% or more.

[0003] During the high-pressure acid leaching process of laterite nickel ore, in order to ensure the leaching efficiency, the temperature in the autoclave needs to be maintained at around 255°C and the pressure in the autoclave needs to be maintained at around 4.7 MPa. However, since the temperature and pressure in the autoclave are affected by a variety of complex factors, in actual production, the temperature and pressure in the autoclave fluctuate greatly, making it difficult to maintain the temperature and pressure in the autoclave at the optimal temperature and pressure conditions, resulting in low leaching efficiency of laterite nickel ore.

[0004] Summary of the Invention

[0005] In view of this, it is necessary to provide a dynamic control method for high-pressure leaching reaction conditions of laterite nickel ore to solve the problem.

[0006] In order to achieve the above object, the present invention provides a method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore, comprising:

[0007] Setting the target temperature and target pressure of the autoclave;

[0008] The thermal power required to heat the feed slurry to the target temperature is obtained according to the target temperature of the autoclave and the operating parameters of the feed slurry;

[0009] According to the metal element composition and pulp concentration of the feed slurry, the average mass flow rate of the acid inlet is determined, and the thermal power brought by the acid inlet is obtained according to the average mass flow rate of the acid inlet;

[0010] Obtain heat loss correction power. The required new steam heat power is obtained based on the heat power required to heat the feed slurry to the target temperature, the heat power brought by the acid feed, and the heat loss correction power.

[0011] Obtaining the operating parameters of the new steam, and obtaining the required flow rate of the new steam according to the required new steam thermal power and the operating parameters of the new steam;

[0012] The real-time flow rate of fresh steam is adjusted to the required fresh steam flow rate. After a first preset time, the real-time pressure of the autoclave is obtained. According to the real-time pressure of the autoclave and the target pressure, the opening of the exhaust valve of the autoclave and the discharge flow rate are adjusted to make the real-time pressure of the autoclave equal to the target pressure.

[0013] After the second preset time, the real-time temperature of the autoclave is obtained, and the flow rate of the new steam is adjusted according to the real-time temperature of the autoclave and the target temperature to make the real-time temperature of the autoclave equal to the target temperature.

[0014] In some embodiments, the operating parameters of the feed slurry include an average mass flow rate of the feed slurry, an equilibrium specific heat capacity of the feed slurry, and a real-time temperature of the feed slurry.

[0015] In some embodiments, the thermal power required to heat the feed slurry to the target temperature is obtained based on the target temperature of the autoclave and the operating parameters of the feed slurry. The specific calculation formula is: ΔT1=T-T1

[0016] in, The thermal power required to heat the feed slurry to the target temperature, is the average mass flow rate of feed slurry, is the equilibrium specific heat capacity of the feed slurry, T is the target temperature of the feed slurry, and T1 is the real-time temperature of the feed slurry.

[0017] In some embodiments, the average mass flow rate of the acid feed is determined based on the metal element composition and slurry concentration of the feed slurry, specifically including:

[0018] Obtain the unit acid consumption of each metal element component of the feed slurry;

[0019] The total acid consumption of the feed slurry is obtained according to the metal element composition and slurry concentration of the feed slurry and the unit acid consumption of each metal element component of the feed slurry;

[0020] The average mass flow rate of the acid feed is determined based on the total acid consumption of the feed slurry.

[0021] In some embodiments, the thermal power brought by the acid inlet is obtained according to the average mass flow rate of the acid inlet, and the specific calculation formula is:

[0022] in, The heat power brought by the acid inlet, is the average mass flow rate of acid inlet, ΔH 0 is the exothermic enthalpy of sulfuric acid, and M3 is the molar mass of sulfuric acid.

[0023] In some embodiments, the heat loss correction power is determined by: determining the heat loss correction power according to the shape, size and thermal insulation capacity of the autoclave.

[0024] In some embodiments, the specific calculation formula for the required new steam thermal power is obtained based on the thermal power required to heat the feed slurry to the target temperature, the thermal power caused by the acid addition, and the heat loss correction power:

[0025] in, is the required new steam thermal power, The heat power brought by the acid inlet, The thermal power required to heat the feed slurry to the target temperature, Correct the power for heat loss.

[0026] In some embodiments, the operating parameters of the live steam include the equilibrium specific heat capacity of the live steam and the temperature of the live steam.

[0027] In some embodiments, the required fresh steam flow rate is obtained according to the required fresh steam thermal power and fresh steam operating parameters. The specific calculation formula is: ΔT2=T2-T

[0028] in, is the required new steam thermal power, is the required fresh steam flow rate, is the equilibrium specific heat capacity of live steam, T2 is the temperature of live steam, and T is the target temperature of the autoclave.

[0029] In some embodiments, the specific method of adjusting the opening of the exhaust valve of the autoclave and the discharge flow rate to make the real-time pressure of the autoclave equal to the target pressure includes:

[0030] If the real-time pressure of the autoclave is lower than the target pressure, the opening of the autoclave's exhaust valve is reduced and the discharge flow rate is reduced;

[0031] If the real-time pressure of the autoclave is greater than the target pressure, the opening of the autoclave's exhaust valve is increased and the discharge flow rate is increased.

[0032] In some embodiments, according to the real-time temperature of the autoclave and the target temperature, the specific method of adjusting the flow rate of fresh steam to make the real-time temperature of the autoclave equal to the target temperature includes:

[0033] If the real-time temperature of the autoclave is lower than the target temperature, the flow rate of fresh steam is increased;

[0034] If the real-time temperature of the autoclave is greater than the target temperature, the flow rate of fresh steam is reduced.

[0035] Compared with the prior art, the beneficial effects of the technical solution proposed in the present invention are as follows: first, the required new steam thermal power is obtained by the target temperature and target pressure of the autoclave, the operating parameters of the feed slurry, the metal element composition and slurry concentration of the feed slurry, and the heat loss correction power; the required new steam flow rate is obtained according to the required new steam thermal power; and the real-time flow rate of the new steam is adjusted to the required new steam flow rate. This process is to preliminarily determine the reaction conditions of the high-pressure leaching reaction according to the feed situation; then, according to the obtained real-time temperature and real-time pressure of the autoclave, the exhaust valve opening, the discharge flow rate and the new steam flow rate are adjusted to make the real-time temperature and real-time pressure in the high-pressure reactor equal to the target temperature and target pressure; this process is to feedback and adjust the reaction control conditions according to the real-time temperature and real-time pressure in the autoclave; through the cooperation of the above two control modes, the temperature and pressure in the autoclave can be maintained at the optimal temperature and optimal pressure conditions, thereby improving the leaching efficiency of laterite nickel ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic flow diagram of an embodiment of a method for dynamically controlling reaction conditions of high-pressure leaching of laterite nickel ore provided by the present invention;

[0037] FIG2 is a flow chart of the method for determining the average mass flow rate of acid inlet in step S3 in FIG1 . DETAILED DESCRIPTION

[0038] 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.

[0039] Referring to FIG. 1 , the present invention provides a method for dynamically controlling reaction conditions of high-pressure leaching of laterite nickel ore, comprising:

[0040] S1. Setting the target temperature and target pressure of the autoclave;

[0041] In this embodiment, the target temperature in the autoclave is 255° C., and the target pressure in the autoclave is 4.7 MPa.

[0042] S2. Obtaining the thermal power required to heat the feed slurry to the target temperature based on the target temperature of the autoclave and the operating parameters of the feed slurry, wherein the operating parameters of the feed slurry include the average mass flow rate of the feed slurry, the equilibrium specific heat capacity of the feed slurry, and the real-time temperature of the feed slurry.

[0043] The specific calculation formula for the thermal power required to heat the feed slurry to the target temperature is: ΔT1=T-T1

[0044] in, The thermal power required to heat the feed slurry to the target temperature, is the average mass flow rate of feed slurry, is the equilibrium specific heat capacity of the feed slurry, T is the target temperature of the feed slurry, and T1 is the real-time temperature of the feed slurry.

[0045] S3. Determine the average mass flow rate of acid inlet according to the metal element composition and slurry concentration of the feed slurry, and obtain the thermal power brought by the acid inlet according to the average mass flow rate of acid inlet;

[0046] Wherein, please refer to Figure 2, according to the metal element composition and pulp concentration of the feed slurry, determine the average mass flow rate of the acid feed, specifically including:

[0047] S31. Obtain the unit acid consumption of each metal element component of the feed slurry. For laterite nickel ore, the metal element components of the feed slurry generally include nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), aluminum (Al), chromium (Cr), magnesium (Mg), and calcium (Ca). The unit acid consumption of these metal elements can be obtained by searching relevant literature.

[0048] S32. Obtaining the total acid consumption of the feed slurry based on the metal element composition and slurry concentration of the feed slurry and the unit acid consumption of each metal element component of the feed slurry;

[0049] S33. Determine the average mass flow rate of the acid feed according to the total acid consumption of the feed slurry.

[0050] Among them, the thermal power brought by the acid inlet is obtained according to the average mass flow rate of the acid inlet. The specific calculation formula is:

[0051] in, The heat power brought by the acid inlet, is the average mass flow rate of acid inlet, ΔH 0 is the exothermic enthalpy of sulfuric acid, and M3 is the molar mass of sulfuric acid.

[0052] S4. Obtain heat loss correction power. The required new steam heat power is obtained based on the heat power required to heat the feed slurry to the target temperature, the heat power brought by the acid feed, and the heat loss correction power.

[0053] The heat loss correction power can be determined by: determining the heat loss correction power based on the shape, size, and insulation capacity of the autoclave; obtaining the heat loss correction power of the autoclave based on equipment test data provided by the autoclave manufacturer; or inferring the heat loss correction power of the autoclave based on production data during actual operation.

[0054] Among them, according to the thermal power required to heat the feed slurry to the target temperature, the thermal power brought by the acid addition, and the heat loss correction power, the specific calculation formula for the required new steam thermal power is:

[0055] in, is the required new steam thermal power, The heat power brought by the acid inlet, The thermal power required to heat the feed slurry to the target temperature, Correct the power for heat loss.

[0056] S5. Obtain operating parameters of the new steam, and obtain the required flow rate of the new steam according to the required new steam thermal power and the new steam operating parameters, wherein the new steam operating parameters include the equilibrium specific heat capacity of the new steam and the temperature of the new steam.

[0057] According to the required new steam thermal power and new steam operating parameters, the required new steam flow rate is obtained. The specific calculation formula is: ΔT2=T2-T

[0058] in, is the required new steam thermal power, is the required fresh steam flow rate, is the equilibrium specific heat capacity of live steam, T2 is the temperature of live steam, and T is the target temperature of the autoclave.

[0059] S6. Adjust the real-time flow rate of new steam to the required flow rate of new steam. After the first preset time, obtain the real-time pressure of the autoclave. According to the real-time pressure of the autoclave and the target pressure, adjust the opening of the exhaust valve of the autoclave and the discharge flow rate to make the real-time pressure of the autoclave equal to the target pressure. In this embodiment, the first preset time is 60s.

[0060] The specific control logic is as follows:

[0061] If the real-time pressure of the autoclave is lower than the target pressure, the opening of the autoclave's exhaust valve is reduced and the discharge flow rate is reduced;

[0062] If the real-time pressure of the autoclave is greater than the target pressure, the opening of the autoclave's exhaust valve is increased and the discharge flow rate is increased.

[0063] S7. After the second preset time, the real-time temperature of the autoclave is obtained, and the flow rate of the fresh steam is adjusted according to the real-time temperature of the autoclave and the target temperature to make the real-time temperature of the autoclave equal to the target temperature. In this embodiment, the second preset time is 0.1 s.

[0064] The specific control logic is as follows:

[0065] If the real-time temperature of the autoclave is lower than the target temperature, the flow rate of fresh steam is increased;

[0066] If the real-time temperature of the autoclave is greater than the target temperature, the flow rate of fresh steam is reduced.

[0067] During the reaction process, with a preset time length (e.g., 90 seconds) as a cycle, in the first part of the preset time (e.g., the first 60 seconds), the reaction conditions of the high-pressure leaching reaction are regulated through steps S1-S5. In the second part of the preset time (e.g., the last 30 seconds), the real-time temperature and real-time pressure in the high-pressure reactor are adjusted to be equal to the target temperature and target pressure through steps S6 and S7. This cycle is repeated to achieve stable reaction effects and efficient production.

[0068] To facilitate understanding of the technical solution provided by the present invention, Table 1 lists the relevant parameters involved in the present invention.

[0069] Table 1 High pressure leaching reaction conditions of laterite nickel ore

[0070] It should be understood that although the steps in the flowchart of FIG1 are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps may be performed in other orders.

[0071] The technical solution provided by the present invention first obtains the required new steam thermal power through the target temperature and target pressure of the autoclave, the operating parameters of the feed slurry, the metal element composition and slurry concentration of the feed slurry, and the heat loss correction power, obtains the required new steam flow rate according to the required new steam thermal power, and adjusts the real-time flow rate of the new steam to the required new steam flow rate. This process is to preliminarily determine the reaction conditions of the high-pressure leaching reaction according to the feed situation, and then adjust the exhaust valve opening, the discharge flow rate and the new steam flow rate according to the obtained real-time temperature and real-time pressure of the autoclave so that the real-time temperature and real-time pressure in the high-pressure reactor are adjusted to be equal to the target temperature and target pressure. This process is to feedback and adjust the reaction control conditions according to the real-time temperature and real-time pressure in the autoclave. Through the cooperation of the above two control modes, the temperature and pressure in the autoclave can be maintained at optimal temperature and optimal pressure conditions, thereby improving the leaching efficiency of laterite nickel ore.

[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 method for dynamically controlling reaction conditions of high-pressure leaching of laterite nickel ore, characterized in that: include: Setting the target temperature and target pressure of the autoclave; The thermal power required to heat the feed slurry to the target temperature is obtained according to the target temperature of the autoclave and the operating parameters of the feed slurry; According to the metal element composition and slurry concentration of the feed slurry, the average mass flow rate of the acid inlet is determined, and the thermal power brought by the acid inlet is obtained according to the average mass flow rate of the acid inlet; Obtain the heat loss correction power, and obtain the required new steam heat power based on the heat power required to heat the feed slurry to the target temperature, the heat power brought by the acid feed, and the heat loss correction power; Obtaining the operating parameters of the new steam, and obtaining the required flow rate of the new steam according to the required new steam thermal power and the operating parameters of the new steam; The real-time flow rate of the new steam is adjusted to the required flow rate of the new steam. After the first preset time, the real-time pressure of the autoclave is obtained. According to the real-time pressure of the autoclave and the target pressure, the opening of the exhaust valve of the autoclave and the discharge flow rate are adjusted to make the real-time pressure of the autoclave equal to the target pressure; After the second preset time, the real-time temperature of the autoclave is obtained, and the flow rate of the new steam is adjusted according to the real-time temperature of the autoclave and the target temperature to make the real-time temperature of the autoclave equal to the target temperature.

2. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: The operating parameters of the feed slurry include the average mass flow rate of the feed slurry, the equilibrium specific heat capacity of the feed slurry, and the real-time temperature of the feed slurry.

3. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 2, characterized in that: According to the target temperature of the autoclave and the operating parameters of the feed slurry, the thermal power required to heat the feed slurry to the target temperature is obtained. The specific calculation formula is: ΔT1=T-T1 in, The thermal power required to heat the feed slurry to the target temperature. is the average mass flow rate of feed slurry, is the equilibrium specific heat capacity of the feed slurry, T is the target temperature of the feed slurry, and T1 is the real-time temperature of the feed slurry.

4. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: According to the metal element composition and slurry concentration of the feed slurry, the average mass flow rate of the acid feed is determined, including: Obtain the unit acid consumption of each metal element component of the feed slurry; The total acid consumption of the feed slurry is obtained according to the metal element composition and slurry concentration of the feed slurry and the unit acid consumption of each metal element component of the feed slurry; The average mass flow rate of the acid feed is determined based on the total acid consumption of the feed slurry.

5. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: The thermal power brought by the acid inlet is obtained according to the average mass flow rate of the acid inlet. The specific calculation formula is: in, The heat power brought by the acid inlet, is the average mass flow rate of acid inlet, ΔH 0 is the exothermic enthalpy of sulfuric acid, and M3 is the molar mass of sulfuric acid.

6. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: The method for determining the heat loss correction power is as follows: the heat loss correction power is determined according to the shape, size and heat preservation capacity of the autoclave.

7. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: According to the thermal power required to heat the feed slurry to the target temperature, the thermal power brought by the acid feed and the heat loss correction power, the specific calculation formula for the required new steam thermal power is: in, is the required new steam thermal power, The heat power brought by the acid inlet, The thermal power required to heat the feed slurry to the target temperature. Correct the power for heat losses.

8. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: The operating parameters of the fresh steam include the equilibrium specific heat capacity of the fresh steam and the temperature of the fresh steam.

9. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 8, characterized in that: According to the required new steam thermal power and the new steam operating parameters, the required new steam flow rate is obtained. The specific calculation formula is: ΔT2=T2-T in, is the required new steam thermal power, is the required fresh steam flow rate, is the equilibrium specific heat capacity of the live steam, T2 is the temperature of the live steam, and T is the target temperature of the autoclave.

10. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: According to the real-time pressure and target pressure of the autoclave, the specific method of adjusting the opening of the exhaust valve of the autoclave and the discharge flow rate to make the real-time pressure of the autoclave equal to the target pressure includes: If the real-time pressure of the autoclave is less than the target pressure, the opening of the exhaust valve of the autoclave is reduced and the discharge flow rate is reduced; If the real-time pressure of the autoclave is greater than the target pressure, the opening of the exhaust valve of the autoclave is increased and the discharge flow rate is increased.

11. The method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore according to claim 1, characterized in that: According to the real-time temperature and the target temperature of the autoclave, the specific method of adjusting the flow rate of the new steam so that the real-time temperature of the autoclave is equal to the target temperature includes: If the real-time temperature of the autoclave is lower than the target temperature, the flow rate of fresh steam is increased; If the real-time temperature of the autoclave is greater than the target temperature, the flow rate of fresh steam is reduced.

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