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

Abstract

The application discloses a dynamic regulation method for high-pressure leaching reaction conditions of laterite nickel ore, which comprises the following steps: setting a target temperature and a target pressure of an autoclave; obtaining a heat power required for heating feed ore slurry to the target temperature; obtaining a heat power brought by acid; obtaining a required new steam heat power; obtaining a required new steam flow; adjusting a real-time flow of the new steam to the required new steam flow, adjusting an exhaust valve opening degree and a discharge 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 application has the beneficial effects that: the reaction conditions of the high-pressure leaching reaction are preliminarily determined according to the feeding condition, then the reaction control conditions are adjusted according to the real-time temperature and the real-time pressure in the autoclave, through cooperation of the above two regulation modes, the temperature and pressure in the autoclave can be maintained under the optimal temperature and pressure conditions, and the leaching efficiency of the laterite nickel ore is improved.

Description

Technical Field

[0001] This invention relates to the field of high-pressure leaching technology for laterite nickel ore, and in particular to a method for dynamically controlling the reaction conditions of high-pressure leaching of laterite nickel ore. Background Technology

[0002] The high-pressure acid leaching process of laterite nickel ore involves leaching the ore slurry with a strong acid solution in a high-temperature, high-pressure autoclave. Under high-temperature and strong acid conditions, selective leaching of nickel and cobalt is achieved, while most of the impurities, such as iron and aluminum, remain in the slag. This ensures the recovery of valuable metals and reduces material consumption. The recovery rates of nickel and cobalt can reach 90% or more.

[0003] In the high-pressure acid leaching process of laterite nickel ore, in order to ensure leaching efficiency, the temperature inside the autoclave needs to be maintained at around 255℃ and the pressure inside the autoclave needs to be maintained at around 4.7 MPa. However, due to the combined influence of a variety of complex factors, the temperature and pressure inside the autoclave fluctuate greatly during actual production, making it difficult to maintain the temperature and pressure inside the autoclave under optimal conditions, resulting in low leaching efficiency of laterite nickel ore. Summary of the Invention

[0004] In view of this, it is necessary to provide a dynamic control method for the high-pressure leaching reaction conditions of laterite nickel ore to solve this problem.

[0005] To achieve the above objectives, the present invention provides a method for dynamically controlling the high-pressure leaching reaction conditions of laterite nickel ore, comprising:

[0006] Set the target temperature and target pressure for the autoclave;

[0007] The heat power required to raise 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.

[0008] The average mass flow rate of acid feed is determined based on the metal element composition and concentration of the feed slurry, and the heat power brought by the acid feed is obtained based on the average mass flow rate of acid feed.

[0009] Obtain the heat loss correction power. Based on the heat power required to raise the feed slurry to the target temperature, the heat power brought by the acid injection, and the heat loss correction power, obtain the required new steam heat power.

[0010] Obtain the operating parameters of the new steam, and based on the required thermal power of the new steam and the operating parameters of the new steam, obtain the required flow rate of the new steam;

[0011] Adjust the real-time flow rate of the new steam to the required flow rate. After the first preset time, obtain the real-time pressure of the high-pressure vessel. Based on the real-time pressure and the target pressure of the high-pressure vessel, adjust the opening of the exhaust valve and the discharge flow rate of the high-pressure vessel to make the real-time pressure of the high-pressure vessel equal to the target pressure.

[0012] After the second preset time, the real-time temperature of the autoclave is obtained. Based on the real-time temperature of the autoclave and the target temperature, the flow rate of the new steam is adjusted so that the real-time temperature of the autoclave is equal to the target temperature.

[0013] In some embodiments, 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.

[0014] In some embodiments, the heat power required to raise 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 as follows:

[0015]

[0016] ΔT1=T-T1

[0017] in, The thermal power required to heat the feed slurry to the target temperature. The average mass flow rate of the feed slurry. T 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.

[0018] In some embodiments, the average mass flow rate of acid feed is determined based on the metal element composition and concentration of the feed slurry, specifically including:

[0019] The unit acid consumption of each metal element composition of the feed slurry is obtained;

[0020] The total acid consumption of the feed slurry is obtained based on the metal element composition and concentration of the feed slurry, as well as the unit acid consumption of each metal element component in the feed slurry.

[0021] The average mass flow rate of acid feed is determined based on the total acid consumption of the feed slurry.

[0022] In some embodiments, the heat power generated by the acid inlet is obtained based on the average mass flow rate of the acid inlet, and the specific calculation formula is as follows:

[0023]

[0024] in, The heat generated by the acid injection. ΔH represents the average mass flow rate of the acid feed. 0M3 is the exothermic enthalpy of sulfuric acid, and M4 is the molar mass of sulfuric acid.

[0025] In some embodiments, the method for determining the heat loss correction power is as follows: the heat loss correction power is determined by the shape, size and heat preservation capacity of the autoclave.

[0026] In some embodiments, the specific calculation formula for 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 acid injection, and the power corrected for heat loss:

[0027]

[0028] in, For the required new steam thermal power, The heat generated by the acid injection. The thermal power required to heat the feed slurry to the target temperature. Correct power for heat loss.

[0029] In some embodiments, the operating parameters of the new steam include the equilibrium specific heat capacity of the new steam and the temperature of the new steam.

[0030] In some embodiments, the required flow rate of the new steam is obtained based on the required new steam thermal power and the operating parameters of the new steam, and the specific calculation formula is as follows:

[0031]

[0032] ΔT2=T2-T

[0033] in, For the required new steam thermal power, For the required flow rate of new steam, T1 represents the equilibrium specific heat capacity of the new steam, T2 represents the temperature of the new steam, and T represents the target temperature of the autoclave.

[0034] In some embodiments, a specific method for adjusting the opening of the exhaust valve and the discharge flow rate of the autoclave based on the real-time pressure and the target pressure of the autoclave to make the real-time pressure of the autoclave equal to the target pressure includes:

[0035] If the real-time pressure of the autoclave is less than the target pressure, reduce the opening of the autoclave's exhaust valve and reduce the discharge flow rate.

[0036] If the real-time pressure of the autoclave is greater than the target pressure, increase the opening of the autoclave's exhaust valve and increase the discharge flow rate.

[0037] In some embodiments, a specific method for adjusting the flow rate of new steam according to the real-time temperature and target temperature of the autoclave to make the real-time temperature of the autoclave equal to the target temperature includes:

[0038] If the real-time temperature of the autoclave is lower than the target temperature, increase the flow rate of the new steam.

[0039] If the real-time temperature of the autoclave is higher than the target temperature, reduce the flow rate of new steam.

[0040] Compared with the prior art, the beneficial effects of the technical solution proposed in this invention are as follows: First, the required new steam thermal power is obtained by considering the target temperature and pressure of the high-pressure reactor, the operating parameters of the feed slurry, the metal element composition and concentration of the feed slurry, and the heat loss correction power. The required new steam flow rate is then obtained based on the required new steam thermal power, and the real-time flow rate of the new steam is adjusted to the required flow rate. This process initially determines the reaction conditions for the high-pressure leaching reaction based on the feed conditions. Next, based on the obtained real-time temperature and pressure of the high-pressure reactor, the opening of the exhaust valve, the discharge flow rate, and the flow rate of the new steam are adjusted to ensure that the real-time temperature and pressure inside the high-pressure reactor are equal to the target temperature and pressure. This process involves adjusting the reaction control conditions based on feedback from the real-time temperature and pressure inside the high-pressure reactor. Through the combination of the above two control modes, the temperature and pressure inside the high-pressure reactor can be maintained at the optimal temperature and pressure conditions, thereby improving the leaching efficiency of laterite nickel ore. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of an embodiment of the dynamic control method for high-pressure leaching reaction conditions of laterite nickel ore provided by the present invention.

[0042] Figure 2 yes Figure 1 A flowchart illustrating the method for determining the average mass flow rate of the acid feed in step S3. Detailed Implementation

[0043] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0044] Please refer to Figure 1 This invention provides a method for dynamically controlling the high-pressure leaching reaction conditions of laterite nickel ore, comprising:

[0045] S1. Set the target temperature and target pressure of the autoclave;

[0046] In this embodiment, the target temperature inside the autoclave is 255°C, and the target pressure inside the autoclave is 4.7 MPa.

[0047] S2. Based on the target temperature of the autoclave and the operating parameters of the feed slurry, obtain the heat power required to raise the feed slurry to the target temperature. 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.

[0048] The specific formula for calculating the heat power required to heat the feed slurry to the target temperature is as follows:

[0049]

[0050] ΔT1=T-T1

[0051] in, The thermal power required to heat the feed slurry to the target temperature. The average mass flow rate of the feed slurry. T 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.

[0052] S3. Determine the average mass flow rate of the acid feed based on the metal element composition and concentration of the feed slurry, and obtain the heat power brought by the acid feed based on the average mass flow rate of the acid feed.

[0053] Please refer to Figure 2 The average mass flow rate of acid feed is determined based on the metal element composition and concentration of the feed slurry, specifically including:

[0054] S31. Obtain the unit acid consumption of each metal element in the feed slurry; for laterite nickel ore, the metal element composition of its feed slurry usually includes 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 consulting relevant literature.

[0055] S32. Obtain 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.

[0056] S33. Determine the average mass flow rate of acid feed based on the total acid consumption of the feed slurry.

[0057] The heat power generated by the influent acid is obtained based on the average mass flow rate of the influent acid, and the specific calculation formula is as follows:

[0058]

[0059] in, The heat generated by the acid injection. ΔH represents the average mass flow rate of the acid feed. 0 M3 is the exothermic enthalpy of sulfuric acid, and M4 is the molar mass of sulfuric acid.

[0060] S4. Obtain the heat loss correction power. Based on the heat power required to raise the feed slurry to the target temperature, the heat power brought by the acid injection, and the heat loss correction power, obtain the required new steam heat power.

[0061] The method for determining the heat loss correction power is as follows: the heat loss correction power is determined by the shape, size and heat preservation capacity of the autoclave; the heat loss correction power of the autoclave can also be obtained by the equipment testing data provided by the autoclave manufacturer; or the heat loss correction power of the autoclave can be inferred from the production data during actual operation.

[0062] The specific calculation formula for the required new steam heat power is as follows, based on the heat power required to raise the feed slurry to the target temperature, the heat power brought by acid injection, and the power correction for heat loss:

[0063]

[0064] in, For the required new steam thermal power, The heat generated by the acid injection. The thermal power required to heat the feed slurry to the target temperature. Correct power for heat loss.

[0065] S5. Obtain the operating parameters of the new steam. Based on the required new steam thermal power and the operating parameters of the new steam, obtain the required flow rate of the new steam. The operating parameters of the new steam include the equilibrium specific heat capacity and the temperature of the new steam.

[0066] Based on the required new steam thermal power and the operating parameters of the new steam, the required flow rate of the new steam is obtained. The specific calculation formula is as follows:

[0067]

[0068] ΔT2=T2-T

[0069] in, For the required new steam thermal power, For the required flow rate of new steam, T1 represents the equilibrium specific heat capacity of the new steam, T2 represents the temperature of the new steam, and T represents the target temperature of the autoclave.

[0070] S6. Adjust the real-time flow rate of the new steam to the required flow rate of the new steam. After a first preset time, obtain the real-time pressure of the high-pressure vessel. Based on the real-time pressure of the high-pressure vessel and the target pressure, adjust the opening of the exhaust valve and the discharge flow rate of the high-pressure vessel to make the real-time pressure of the high-pressure vessel equal to the target pressure. In this embodiment, the first preset time is 60s.

[0071] The specific control logic is as follows:

[0072] If the real-time pressure of the autoclave is less than the target pressure, reduce the opening of the autoclave's exhaust valve and reduce the discharge flow rate.

[0073] If the real-time pressure of the autoclave is greater than the target pressure, increase the opening of the autoclave's exhaust valve and increase the discharge flow rate.

[0074] S7. After the second preset time, the real-time temperature of the autoclave is obtained. Based on the real-time temperature and the target temperature of the autoclave, the flow rate of new steam is adjusted to make the real-time temperature of the autoclave equal to the target temperature. In this embodiment, the second preset time is 0.1s.

[0075] The specific control logic is as follows:

[0076] If the real-time temperature of the autoclave is lower than the target temperature, increase the flow rate of the new steam.

[0077] If the real-time temperature of the autoclave is higher than the target temperature, reduce the flow rate of new steam.

[0078] During the reaction process, a preset time length (e.g., 90s) is used as the cycle. In the first part of the preset time (e.g., the first 60s), the reaction conditions of the high-pressure leaching reaction are adjusted through steps S1-S5. In the second part of the preset time (e.g., the last 30s), 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 results and efficient production.

[0079] To facilitate understanding of the technical solutions provided by this invention, Table 1 lists the relevant parameters involved in this invention.

[0080] Table 1 High-pressure leaching reaction conditions for laterite nickel ore

[0081]

[0082] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order in which these steps are executed, and they can be performed in other orders.

[0083] The technical solution provided by this invention first obtains the required new steam thermal power by considering the target temperature and pressure of the autoclave, the operating parameters of the feed slurry, the metal element composition and concentration of the feed slurry, and the heat loss correction power. Based on the required new steam thermal power, the required new steam flow rate is obtained, and the real-time flow rate of the new steam is adjusted to the required flow rate. This process initially determines the reaction conditions for the high-pressure leaching reaction based on the feed conditions. Then, based on the obtained real-time temperature and pressure of the autoclave, the opening of the exhaust valve, the discharge flow rate, and the flow rate of the new steam are adjusted to ensure that the real-time temperature and pressure inside the autoclave are equal to the target temperature and pressure. This process involves adjusting the reaction control conditions based on feedback from the real-time temperature and pressure inside the autoclave. Through the combination of these two control modes, the temperature and pressure inside the autoclave can be maintained at optimal temperature and pressure conditions, thereby improving the leaching efficiency of laterite nickel ore.

[0084] The above description is only a preferred 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 conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

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

2. The method for dynamically controlling the high-pressure leaching reaction conditions 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 high-pressure leaching reaction conditions of laterite nickel ore according to claim 2, characterized in that, The heat power required to raise 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 as follows: ΔT1=T-T1 in, The thermal power required to heat the feed slurry to the target temperature. The average mass flow rate of the feed slurry. T 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 high-pressure leaching reaction conditions of laterite nickel ore according to claim 1, characterized in that, The average mass flow rate of acid feed is determined based on the metal element composition and concentration of the feed slurry, specifically including: The unit acid consumption of each metal element composition of the feed slurry is obtained; The total acid consumption of the feed slurry is obtained based on the metal element composition and concentration of the feed slurry, as well as the unit acid consumption of each metal element component in the feed slurry. The average mass flow rate of acid feed is determined based on the total acid consumption of the feed slurry.

5. The method for dynamically controlling the high-pressure leaching reaction conditions of laterite nickel ore according to claim 1, characterized in that, The heat power generated by the influent acid is obtained based on the average mass flow rate of the influent acid. The specific calculation formula is as follows: in, The heat generated by the acid injection. ΔH represents the average mass flow rate of the acid feed. 0 M3 is the exothermic enthalpy of sulfuric acid, and M4 is the molar mass of sulfuric acid.

6. The method for dynamically controlling the high-pressure leaching reaction conditions 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 by the shape, size and heat preservation capacity of the autoclave.

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

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

9. The method for dynamically controlling the high-pressure leaching reaction conditions of laterite nickel ore according to claim 8, characterized in that, Based on the required new steam thermal power and the operating parameters of the new steam, the required flow rate of the new steam is obtained. The specific calculation formula is as follows: ΔT2=T2-T in, For the required new steam thermal power, For the required flow rate of new steam, T1 represents the equilibrium specific heat capacity of the new steam, T2 represents the temperature of the new steam, and T represents the target temperature of the autoclave.

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

11. The method for dynamically controlling the high-pressure leaching reaction conditions of laterite nickel ore according to claim 1, characterized in that, The specific methods for adjusting the flow rate of new steam to make the real-time temperature of the autoclave equal to the target temperature, based on the real-time temperature and target temperature of the autoclave, include: If the real-time temperature of the autoclave is lower than the target temperature, increase the flow rate of new steam; if the real-time temperature of the autoclave is higher than the target temperature, decrease the flow rate of new steam.

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