System and method for regulating and controlling concentration of laterite-nickel ore high-pressure leaching ore pulp

Abstract

The invention provides a laterite-nickel ore high-pressure leaching ore pulp concentration regulation and control system and method, and belongs to the technical field of metallurgy. The system comprises a thickener, a high-pressure reaction kettle, a circulating leaching tank and an automatic regulation and control device; the bottom flow of the thickener is connected with the feeding end of the high-pressure reaction kettle, and the discharging end of the high-pressure reaction kettle is connected with the circulating leaching tank; and the automatic regulation and control device is used for obtaining the iron ion concentration and the silicon ion concentration in the circulating leaching tank, and reducing the feeding ore pulp concentration of the high-pressure reaction kettle under the condition that the sum of the iron ion concentration and the silicon ion concentration exceeds a target concentration threshold value. Under the condition that the sum of the concentration of the iron ions and the concentration of the silicon ions exceeds the target concentration threshold value, the concentration of the feeding ore pulp of the high-pressure reaction kettle is reduced, so that the concentration of the iron ions and the concentration of the silicon ions in the ore pulp are regulated and controlled in real time, and more iron ions and silicon ions are prevented from being leached in the high-pressure leaching stage; the subsequent multi-stage countercurrent washing flocculent precipitation effect is influenced.

Description

Technical Field

[0001] The present application relates to the field of metallurgy technology, and in particular to a system and method for controlling the concentration of slurry in high-pressure leaching of laterite nickel ore. Background Art

[0002] Currently, in the hydrometallurgical process of laterite nickel ore, after the slurry undergoes high-pressure leaching, circulating leaching, and multi-stage pre-neutralization, it is necessary to use multi-stage countercurrent washing to fully wash the nickel, cobalt, and manganese in the slurry underflow into the solution for solid-liquid separation. However, in practical applications, the flocculation and sedimentation effect of multi-stage countercurrent washing is often poor, which is not conducive to the solid-liquid separation of the solution containing nickel, cobalt, and manganese from the slag.

[0003] The poor flocculation and sedimentation effects of multi-stage countercurrent washing are due to excessively high concentrations of ferric iron and silicon ions in the slurry. These high concentrations are due to the high iron and silicon content of the laterite nickel ore, which results in a high amount of iron and silicon ions being leached during the high-pressure leaching stage. Therefore, a control system is urgently needed to prevent the poor flocculation and sedimentation effects of multi-stage countercurrent washing. Summary of the Invention

[0004] In view of this, it is necessary to provide a laterite nickel ore high-pressure leaching slurry concentration control system and method to achieve real-time control of the iron ion concentration and silicon ion concentration in the slurry, thereby avoiding the leaching of a large amount of iron ions and silicon ions during the high-pressure leaching stage, affecting the subsequent multi-stage countercurrent washing flocculation precipitation effect.

[0005] In order to solve the above problems, on the one hand, the present application provides a laterite nickel ore high-pressure leaching slurry concentration control system, comprising: a thickener, a high-pressure reactor, a circulating leaching tank, an ion concentration collection device and an automatic control device; The underflow of the thickener is connected to the feed end of the high-pressure reactor, and the discharge end of the high-pressure reactor is connected to the circulating leaching tank; The ion concentration collecting device is used to collect the iron ion concentration and the silicon ion concentration in the circulating leaching tank, and send the iron ion concentration and the silicon ion concentration to the automatic control device; The automatic control device is used to control the feed slurry concentration of the high-pressure reactor to decrease when the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold.

[0006] In a possible implementation, the automatic control device is further configured to obtain the discharge slurry concentration of the thickener, and control the feed slurry concentration of the high-pressure reactor to stop decreasing when the discharge slurry concentration reaches a target concentration value.

[0007] In one possible implementation, obtaining the discharge slurry concentration of the thickener includes: Obtaining the feed slurry concentration, feed slurry density, discharge slurry density, settling area and discharge volume flow rate of the thickener, as well as the settling rate of flocs; The discharge slurry concentration of the thickener is obtained based on the feed slurry concentration, feed slurry density, discharge slurry density, settling area and discharge volume flow rate of the thickener, and the settling rate of the flocs.

[0008] In one possible implementation, the discharge slurry concentration of the thickener is determined based on the following formula:

[0009] in, is the sedimentation rate of flocs, C 1 is the feed slurry concentration of the thickener, r 1 is the feed slurry density of the thickener, C 2 is the discharge slurry concentration of the thickener, r 2 is the discharge slurry density of the thickener, S is the settling area of ​​the thickener, G is the discharge volume flow rate.

[0010] In a possible implementation, obtaining the sedimentation rate of flocs includes: Obtaining the initial settling velocity of the material in the thickener when no flocculant is added; obtaining a concentration of a flocculant in a liquid phase of the thickener, and determining a ratio between a settling velocity of the flocs and the initial settling velocity based on the concentration of the flocculant in the liquid phase; The settling rate of the flocs is determined based on the initial settling velocity and the ratio.

[0011] In a possible implementation, the ratio of the settling velocity of the flocs to the initial settling velocity is determined based on the following formula:

[0012] in, C is the concentration of flocculant in the liquid phase of the thickener, is a constant calibrated by experiment, k It is the ratio between the settling velocity of the flocs and the initial settling velocity.

[0013] In one possible implementation, obtaining the concentration of the flocculant in the liquid phase of the thickener includes: Obtaining the amount of flocculant added, as well as the feed slurry concentration and feed mass flow rate of the thickener; The concentration of the flocculant in the liquid phase of the thickener is determined based on the amount of flocculant added, as well as the feed slurry concentration and feed mass flow rate of the thickener.

[0014] In one possible implementation, the concentration of the flocculant in the liquid phase of the thickener is determined based on the following formula:

[0015] in, m is the amount of flocculant added, C is the concentration of flocculant in the liquid phase of the thickener, C 1 is the feed slurry concentration of the thickener, v 0 is the feed mass flow rate of the thickener.

[0016] On the other hand, the present application also provides a method for controlling the concentration of slurry in high-pressure leaching of laterite nickel ore, which is applied to any of the above-mentioned systems, and comprises: The iron ion concentration and silicon ion concentration in the circulating leaching tank are obtained based on the ion concentration collection by the automatic control device; Based on the fact that the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the automatic control device controls the feed slurry concentration of the high-pressure reactor to decrease.

[0017] In one possible implementation, the method for controlling slurry concentration in high-pressure leaching of laterite nickel ore further includes: The discharge slurry concentration of the thickener is obtained based on the automatic control device, and when the discharge slurry concentration reaches a target concentration value, the feed slurry concentration of the high-pressure reactor is controlled to stop decreasing.

[0018] The beneficial effect of adopting the above-mentioned implementation method is as follows: the laterite nickel ore high-pressure leaching slurry concentration control system and method provided in the present application connects the underflow of the thickener to the feed end of the high-pressure reactor, and connects the discharge end of the high-pressure reactor to the circulating leaching tank; after using an ion concentration detection device to detect the iron ion concentration and silicon ion concentration in the circulating leaching tank, the iron ion concentration and silicon ion concentration in the circulating leaching tank are obtained by an automatic control device. When the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the feed slurry concentration of the high-pressure reactor is controlled to decrease, thereby realizing real-time control of the iron ion concentration and silicon ion concentration in the slurry, avoiding the leaching of a large amount of iron ions and silicon ions in the high-pressure leaching stage, affecting the subsequent multi-stage countercurrent washing flocculation precipitation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a functional block diagram of an embodiment of a laterite nickel ore high-pressure leaching slurry concentration control system provided in this application; Figure 2 This is a flow chart of an embodiment of the method for controlling slurry concentration in high-pressure leaching of laterite nickel ore provided in this application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0022] In the description of the embodiments of the present application, unless otherwise specified, “a plurality of” means two or more.

[0023] The terms "including" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or device comprising a series of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules that are not explicitly listed or are inherent to these processes, methods, products or devices.

[0024] The naming or numbering of the steps in the embodiments of the present application does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0025] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] The present application provides a system and method for controlling slurry concentration in high-pressure leaching of laterite nickel ore, which are described below.

[0027] like Figure 1 As shown, the present application provides a laterite nickel ore high-pressure leaching slurry concentration control system, comprising: a thickener 101, a high-pressure reactor 102, a circulating leaching tank 103, an ion concentration collection device 105 and an automatic control device 104; The underflow of the thickener 101 is connected to the feed end of the high-pressure reactor 102, and the discharge end of the high-pressure reactor 102 is connected to the circulating leaching tank 103; The ion concentration collecting device 105 is used to collect the iron ion concentration and the silicon ion concentration in the circulating leaching tank 103 and send the iron ion concentration and the silicon ion concentration to the automatic control device 104; The automatic control device 104 is used to control the feed slurry concentration of the high-pressure reactor 102 to decrease when the sum of the iron ion concentration and the silicon ion concentration exceeds a target concentration threshold.

[0028] It can be understood that the laterite nickel ore high-pressure leaching slurry concentration control system provided in the present application includes a thickener 101, a high-pressure reactor 102, a circulating leaching tank 103 and an automatic control device 104. The bottom flow of the thickener 101 is connected to the feed end of the high-pressure reactor 102, and the discharge end of the high-pressure reactor 102 is connected to the circulating leaching tank 103. The automatic control device 104 detects the concentration of iron ions and silicon ions in the circulating leaching tank 103 in real time through the detection module. When the sum of the concentrations of iron ions and silicon ions exceeds the set threshold, the feed slurry concentration of the high-pressure reactor 102 is controlled to be reduced, thereby realizing real-time adjustment of the iron ion concentration and silicon ion concentration in the slurry, avoiding more iron ions and silicon ions being leached in the high-pressure leaching stage, affecting the subsequent multi-stage countercurrent washing flocculation precipitation effect.

[0029] The detection port of the ion concentration collection device 105 can be connected to the circulating leaching tank 103 to obtain a portion of the ore pulp in the circulating leaching tank 103, and perform ion composition analysis on the portion of the ore pulp to obtain the iron ion concentration and the silicon ion concentration. It is easy to understand that the ion concentration collection device 105 can use conventional detection equipment in the prior art and other feasible detection methods to detect the iron ion concentration and the silicon ion concentration in the ore pulp in the circulating leaching tank 103.

[0030] The feed slurry first enters the thickener 101, where it is thickened based on the principle of gravity sedimentation. The underflow of the thickener is sent to the high-pressure reactor 102 to promote the leaching of nickel, cobalt and manganese under high temperature and high pressure. Finally, the leached slurry is sent to the circulating leaching tank 103.

[0031] The core idea of ​​this application is to regulate the feed slurry concentration of the high-pressure reactor 102 according to the concentration of iron ions and silicon ions in the discharge of the high-pressure reactor 102 to improve the multi-stage countercurrent washing flocculation precipitation effect.

[0032] In some embodiments, the automatic control device 104 is further used to obtain the discharge slurry concentration of the thickener 101, and when the discharge slurry concentration reaches the target concentration value, control the feed slurry concentration of the high-pressure reactor 102 to stop decreasing.

[0033] It is understandable that the feed slurry concentration of the autoclave 102 is consistent with the discharge slurry concentration of the thickener 101. When the discharge slurry concentration of the thickener 101 reaches the target concentration value, it means that the feed slurry concentration of the autoclave 102 also reaches the target concentration value.

[0034] In some embodiments, obtaining the discharge slurry concentration of the thickener 101 includes: Obtaining the feed slurry concentration, feed slurry density, discharge slurry density, settling area and discharge volume flow rate of the thickener 101, as well as the settling rate of the flocs; The discharge slurry concentration of the thickener 101 is obtained based on the feed slurry concentration, feed slurry density, discharge slurry density, settling area and discharge volume flow rate of the thickener 101, and the settling rate of the flocs.

[0035] Furthermore, the discharge slurry concentration of the thickener 101 is determined based on the following formula:

[0036] in, is the sedimentation rate of flocs, C 1 is the feed slurry concentration of thickener 101, r 1 is the feed slurry density of thickener 101, C 2 is the discharge slurry concentration of thickener 101, r 2 is the discharge slurry density of thickener 101, S is the settling area of ​​the thickener 101, G is the discharge volume flow rate.

[0037] It is understandable that the core purpose of adding flocculants is to increase the settling rate of the material. In a given thickener 101, in order to achieve the target discharge concentration and flow rate, the settling rate of the flocs after adding flocculants must satisfy the above relationship.

[0038] In some embodiments, obtaining the sedimentation rate of the flocs comprises: Obtaining the initial settling velocity of the material in the thickener 101 when no flocculant is added; Obtaining the concentration of the flocculant in the liquid phase of the thickener 101, and determining the ratio between the settling velocity of the flocs and the initial settling velocity based on the concentration of the flocculant in the liquid phase; The settling rate of the flocs is determined based on the initial settling velocity and the ratio.

[0039] Furthermore, the ratio of the settling velocity of the flocs to the initial settling velocity is determined based on the following formula:

[0040] in, C is the concentration of flocculant in the liquid phase of thickener 101, is a constant calibrated by experiment, k It is the ratio between the settling velocity of the flocs and the initial settling velocity.

[0041] It can be understood that the initial settling velocity of the material without adding flocculant satisfies the following relationship:

[0042] in, is the initial sinking velocity, r 3 is the material density, r 0 is the liquid density, g is the acceleration due to gravity, d is the average particle size of the material, is the initial viscosity of the feed slurry to the thickener 101 (without flocculant).

[0043] With the addition of flocculants, the settling rate of the material changes. The settling rate of the material at this time is proportional to the settling rate when no flocculants are added. k = Vmin / Va , Vmin is the settling rate of flocs after adding flocculants, Va is the initial sinking velocity, k The value satisfies the above relationship with the flocculant concentration in the liquid phase.

[0044] In some embodiments, obtaining the concentration of the flocculant in the liquid phase of the thickener 101 includes: Obtaining the amount of flocculant added, as well as the feed slurry concentration and feed mass flow rate of the thickener 101; The concentration of the flocculant in the liquid phase of the thickener 101 is determined based on the amount of flocculant added, as well as the feed slurry concentration and feed mass flow rate of the thickener 101 .

[0045] In some embodiments, the concentration of the flocculant in the liquid phase of the thickener 101 is determined based on the following formula:

[0046] in, m is the amount of flocculant added, C is the concentration of flocculant in the liquid phase of thickener 101, C 1 is the feed slurry concentration of thickener 101, v 0 is the feed mass flow rate of the thickener 101.

[0047] The present application also provides a method for controlling the concentration of slurry in high-pressure leaching of laterite nickel ore, which is applied to the above-mentioned system, such as Figure 2 As shown, the method includes: S201, the iron ion concentration and silicon ion concentration in the circulating leaching tank 103 are obtained based on the ion concentration collection by the automatic control device 104; S202 : Based on the automatic control device 104 , when the sum of the iron ion concentration and the silicon ion concentration exceeds a target concentration threshold, controlling the feed slurry concentration of the high-pressure reactor 102 to decrease.

[0048] In some embodiments, the method for controlling the concentration of slurry in high-pressure leaching of laterite nickel ore further comprises: The discharge slurry concentration of the thickener 101 is obtained based on the automatic control device 104 , and when the discharge slurry concentration reaches a target concentration value, the feed slurry concentration of the high-pressure reactor 102 is controlled to stop decreasing.

[0049] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0050] The above is a detailed introduction to the laterite nickel ore high-pressure leaching slurry concentration control system and method provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A laterite nickel ore high pressure leaching slurry concentration control system, characterized in that: include: Thickener, high-pressure reactor, circulating leaching tank, ion concentration collection device and automatic control device; The underflow of the thickener is connected to the feed end of the high-pressure reactor, and the discharge end of the high-pressure reactor is connected to the circulating leaching tank; The ion concentration collecting device is used to collect the iron ion concentration and the silicon ion concentration in the circulating leaching tank, and send the iron ion concentration and the silicon ion concentration to the automatic control device; The automatic control device is used to control the feed slurry concentration of the high-pressure reactor to decrease when the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold.

2. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 1, characterized in that: The automatic control device is further used to obtain the discharge slurry concentration of the thickener, and control the feed slurry concentration of the high-pressure reactor to stop decreasing when the discharge slurry concentration reaches a target concentration value.

3. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 2, characterized in that: Obtaining the discharge slurry concentration of the thickener, including: Obtaining the feed slurry concentration, feed slurry density, discharge slurry density, settling area and discharge volume flow rate of the thickener, as well as the settling rate of flocs; The discharge slurry concentration of the thickener is obtained based on the feed slurry concentration, feed slurry density, discharge slurry density, settling area and discharge volume flow rate of the thickener, and the settling rate of the flocs.

4. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 3, characterized in that: The discharge slurry concentration of the thickener is determined based on the following formula: in, is the sedimentation rate of flocs, C 1 is the feed slurry concentration of the thickener, ρ 1 is the feed slurry density of the thickener, C 2 is the discharge slurry concentration of the thickener, ρ 2 is the discharge slurry density of the thickener, S is the settling area of ​​the thickener, G is the discharge volume flow rate.

5. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 3, characterized in that: Obtain the sedimentation rate of flocs, including: Obtaining the initial settling velocity of the material in the thickener when no flocculant is added; obtaining a concentration of a flocculant in a liquid phase of the thickener, and determining a ratio between a settling velocity of the flocs and the initial settling velocity based on the concentration of the flocculant in the liquid phase; The settling rate of the flocs is determined based on the initial settling velocity and the ratio.

6. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 5, characterized in that: The ratio between the settling velocity of the flocs and the initial settling velocity is determined based on the following formula: in, C is the concentration of flocculant in the liquid phase of the thickener, is a constant calibrated by experiment, k It is the ratio between the settling velocity of the flocs and the initial settling velocity.

7. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 5, characterized in that: Obtaining the concentration of the flocculant in the liquid phase of the thickener, comprising: Obtaining the amount of flocculant added, as well as the feed slurry concentration and feed mass flow rate of the thickener; The concentration of the flocculant in the liquid phase of the thickener is determined based on the amount of flocculant added, as well as the feed slurry concentration and feed mass flow rate of the thickener.

8. The laterite nickel ore high pressure leaching slurry concentration control system according to claim 7, characterized in that: The concentration of the flocculant in the liquid phase of the thickener is determined based on the following formula: in, m is the amount of flocculant added, C is the concentration of flocculant in the liquid phase of the thickener, C 1 is the feed slurry concentration of the thickener, v 0 is the feed mass flow rate of the thickener.

9. A method for controlling slurry concentration in high-pressure leaching of laterite nickel ore, characterized in that: The method is applied to the system according to any one of claims 1 to 8, and the method includes: The iron ion concentration and silicon ion concentration in the circulating leaching tank are obtained based on the ion concentration collection by the automatic control device; Based on the fact that the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the automatic control device controls the feed slurry concentration of the high-pressure reactor to decrease.

10. The method for controlling slurry concentration of laterite nickel ore high-pressure leaching according to claim 9, characterized in that: Also includes: The discharge slurry concentration of the thickener is obtained based on the automatic control device, and when the discharge slurry concentration reaches a target concentration value, the feed slurry concentration of the high-pressure reactor is controlled to stop decreasing.

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