Ferronickel raw material treatment method and device

Abstract

The invention provides a treatment method and device for a ferronickel raw material. The treatment method of the ferronickel raw material comprises an acid leaching process, a replacement process and a separation process. In the acid leaching process, a first ferronickel raw material is in contact with an acidic material for acid leaching treatment, and a leaching solution is obtained; in the replacement procedure, a second ferronickel raw material and the leaching solution are subjected to a replacement reaction, and a reaction solution is obtained; in the separation process, the reaction liquid is subjected to first solid-liquid separation to obtain a nickel-rich solid phase and an iron-containing separation liquid. After acid leaching treatment, ferronickel in the first ferronickel raw material can be dissolved out to a certain extent; according to the method, the second ferronickel raw material and the leachate are subjected to the replacement reaction, nickel ions released in the acid leaching process can be converted into nickel elementary substances through the second ferronickel raw material under the condition that allogenic materials and other auxiliary materials are not introduced, in-situ improvement of the nickel grade is guaranteed, and meanwhile release of iron is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydrometallurgy, and particularly relates to a processing method and device for nickel-iron raw materials. BACKGROUND

[0002] Nickel-iron raw materials contain rich nickel-iron resources. Currently, high-grade nickel is usually produced by adopting a pyrometallurgical smelting method in the industry; however, the production and processing cost is greatly affected by the nickel grade, and the iron resources in the nickel-iron raw materials are finally produced in the form of iron-silicon slag, and the sales price is low, so that the iron resources cannot be efficiently utilized. Nickel-iron hydrometallurgical processing is another processing method for nickel-iron raw materials, and in the process of nickel-iron hydrometallurgical processing, the nickel-iron raw materials generally need to be subjected to processes such as leaching, auxiliary material removal and separation, so as to separate nickel and iron in the nickel-iron raw materials.

[0003] In order to separate nickel and iron in the nickel-iron raw materials, a large amount of auxiliary materials is generally added in the process of the existing hydrometallurgical processing, which not only causes excessive consumption of the auxiliary materials and increases the processing cost, but also easily causes the auxiliary material residues and easily generates other by-products, thereby increasing the processing difficulty; therefore, in the existing research, the hydrometallurgical processing of the nickel-iron raw materials more depends on a large amount of auxiliary materials for nickel-iron separation, and the nickel grade of the nickel-iron raw materials is not in-situ improved.

[0004] In view of this, it is necessary to provide a processing method and device for nickel-iron raw materials, so as to solve or at least alleviate the technical problem of how to in-situ improve the nickel grade of the nickel-iron raw materials in the process of hydrometallurgical processing of the nickel-iron raw materials. SUMMARY

[0005] The main purpose of the present application is to provide a processing method and device for nickel-iron raw materials, which aims to solve the technical problem of how to in-situ improve the nickel grade of the nickel-iron raw materials in the process of hydrometallurgical processing of the nickel-iron raw materials.

[0006] To achieve the above-mentioned purpose, the present application provides a processing method for nickel-iron raw materials, comprising: An acid leaching process: a first nickel-iron raw material is subjected to acid leaching treatment by being contacted with an acidic substance, so as to obtain a leaching solution; the pH value of the leaching solution is 3.0-4.0; A displacement process: a second nickel-iron raw material is subjected to a displacement reaction with the leaching solution, so as to obtain a reaction solution; A separation process: the reaction solution is subjected to a first solid-liquid separation, so as to obtain a nickel-rich solid phase and an iron-containing separation solution.

[0007] In the method for processing the nickel-iron raw material provided by the application, after the acid leaching treatment, the nickel-iron in the first nickel-iron raw material can be dissolved to a certain extent; on the basis of controlling the pH value of the leaching solution, the second nickel-iron raw material and the leaching solution are subjected to a displacement reaction, so that under the condition of not introducing exogenous substances and other auxiliary materials, the nickel ions released in the acid leaching process are converted into elemental nickel by the second nickel-iron raw material, which not only ensures the in-situ improvement of the nickel grade, but also ensures the release of iron at the same time; after solid-liquid separation, the nickel-rich solid phase obtained by the application is higher-grade nickel, and the iron-containing separation liquid obtained contains more iron. In addition, since the application does not depend on other auxiliary materials, the processing cost will be lower, and auxiliary material residues and harmful by-products are less likely to be produced, which is safer and easier to operate.

[0008] In some embodiments of the application, the acid leaching treatment at least meets one of the following conditions: A: the temperature of the acid leaching treatment is not less than 50°C; Optionally, the temperature of the acid leaching treatment is 50-90°C; B: in the acid leaching treatment, the first nickel-iron raw material is in the form of a slurry solution and is in contact with the acidic substance; Optionally, the slurry solution comprises the first nickel-iron raw material and water; Optionally, the liquid-solid ratio of the water and the first nickel-iron raw material is not less than 3L:1kg; optionally, the liquid-solid ratio is 3-5L:1kg; C: the length of the acid leaching treatment is not less than 4h; Optionally, the length of the acid leaching treatment is 4-15h, optionally, 4-10h or 10-14h; D: the acid leaching treatment comprises: adjusting the pH value to be not more than 3.0 by using the acidic substance, and optionally, adjusting the pH value to be 1.0-3.0; E: in the acid leaching treatment, the amount of the acidic substance is controlled according to the theoretical iron leaching rate of 40-70%; F: the acidic substance used in the acid leaching treatment comprises at least one of sulfuric acid and hydrochloric acid; G: the acid leaching treatment further comprises, after adding the acidic substance, stabilizing for 0-2h, and then performing the displacement process after the pH value of the slurry solution rises to 3.0-4.0.

[0009] In some embodiments of the application, the composition of the leaching solution comprises Fe 2+ : 78-105g / L, Fe 3+ : 0.1-0.3g / L, Ni 2+ : 1-7g / L; Optionally, the composition of the leaching solution further comprises Co 2+ : 0.1-0.3g / L.

[0010] In some embodiments of the present application, the mass percentage of Fe in the first and second nickel-iron raw materials is independently 78-85%, and the mass percentage of Ni is independently 8-11%; Optionally, the first and second nickel-iron raw materials further comprise Co. Optionally, the first and second nickel-iron raw materials have the same composition. Optionally, the mass ratio of the first and second nickel-iron raw materials is 5-20:1. Optionally, the first nickel-iron raw material is directly subjected to the acid leaching treatment to obtain the leaching solution. Optionally, the particle size D100 of the first nickel-iron raw material is ≤3 cm; optionally, the particle size D80 is ≤5 mm; and optionally, the particle size D10 is ≥1 mm. Optionally, the second nickel-iron raw material is in powder form, and the particle size of the second nickel-iron raw material is smaller than that of the first nickel-iron raw material; optionally, the particle size D80 of the second nickel-iron raw material is ≤180 μm; and optionally, the particle size D100 is ≤210 μm. Optionally, the temperature of the displacement reaction is 60-90°C. Optionally, the duration of the displacement reaction is not less than 2 h, and is optionally 2-6 h. Optionally, the first solid-liquid separation is by centrifugal separation. Optionally, the pH value of the reaction solution is 4.0-6.0, and further, the pH value is 5.0-6.0.

[0011] In some embodiments of the present application, in the separation process, the pH value of the reaction solution is adjusted back to 3.0-4.0 before the first solid-liquid separation.

[0012] In some embodiments of the present application, the total process time of the adjustment and the first solid-liquid separation is not more than 0.5 h. Optionally, the acidic substance used in the adjustment is the same as that used in the acid leaching process.

[0013] In some embodiments of the present application, in the nickel-rich solid phase, the mass percentage of Fe is 67.60-70.55% (not including water), the mass percentage of Ni is 15.46-16.19%, and the other components are 13.76-16.21%. Optionally, in the nickel-rich solid phase, the mass percentage of water is 5-15%.

[0014] In some embodiments of the present application, the treatment method further comprises a pH adjusting process, in which the pH value of the iron-containing separation solution is adjusted to 1.5-2.5. Optionally, the acid used in the pH adjusting process is the same as the acid used in the acid leaching process. Optionally, the treatment method further comprises a fine filtration process, in which the iron-containing separation solution is subjected to a second solid-liquid separation to obtain a ferrous sulfate solution. Optionally, the second solid-liquid separation comprises filtration separation. Optionally, the ferrous sulfate solution comprises Fe 2+ : 80-110 g / L, Fe 3+ : 0.1-1 g / L, Ni 2+ : 2-35 mg / L. Optionally, the ferrous sulfate solution further comprises Co 2+ : 0.5-5 mg / L. Optionally, the treatment method further comprises a crystallization process, in which the ferrous sulfate solution is subjected to evaporation crystallization to obtain ferrous sulfate crystals.

[0015] The present application also provides a device for treating a nickel-iron raw material, which comprises: a feeding unit, which comprises a first nickel-iron raw material feeding assembly, a second nickel-iron raw material feeding assembly, and an acid feeding assembly; a leaching impurity removal unit, which comprises a leaching impurity removal container and a first pH monitoring module arranged thereon, and is connected to the feeding unit; a nickel-iron separation unit, which is connected to the discharge port of the leaching impurity removal unit; a control unit, which is configured to control the start and stop of the second nickel-iron raw material feeding assembly according to the data input by the first pH monitoring module.

[0016] In some embodiments of the present application, the device further comprises a pH adjusting unit, which comprises a pH adjusting container and a second pH monitoring module arranged thereon, and is connected to the liquid outlet of the nickel-iron separation unit; Optionally, the device further comprises a fine filtration unit, which is connected to the discharge port of the pH adjusting unit; Optionally, the device further comprises a crystallization unit, which is connected to the liquid outlet of the fine filtration unit; Optionally, the device further comprises a time monitoring unit, which is electrically connected to the nickel-iron separation unit; Optionally, the configuration of the control unit further comprises one or more of the following: a: before controlling the second nickel-iron raw material feeding assembly to feed, according to preset acid leaching data, controlling the start and stop of the acidic substance feeding assembly; Optionally, the acid leaching data includes the feeding amount of the acidic substance. b: after controlling the second nickel-iron raw material feeding assembly to complete feeding, according to the data input by the first pH monitoring module, controlling the start and stop of the acidic substance feeding assembly; c: according to the callback start time data monitored by the time monitoring unit, controlling the start and stop of the nickel-iron separation unit; the callback start time is the time when the acidic substance feeding is controlled to start after the second nickel-iron raw material feeding assembly completes feeding. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0018] Figure 1 FIG. 1 is a flowchart of the processing method of the nickel-iron raw material in an embodiment of the present application. Figure 2 FIG. 2 is a schematic diagram of part of the modules of the processing device of the nickel-iron raw material in an embodiment of the present application.

[0019] FIG. 1 is a flowchart of the processing method of the nickel-iron raw material in an embodiment of the present application.

[0020] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] Moreover, the technical solutions in each of the embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it. When the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.

[0023] When the embodiments give a numerical range, it should be understood that, unless otherwise specified by the present application, both endpoints of each numerical range and any number between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application can be implemented using any method, equipment and material of the prior art similar or equivalent to the method, equipment and material described in the embodiments of the present application, together with the mastery of the prior art by the person skilled in the art and the description of the present application.

[0024] At present, high nickel matte is generally produced by the method of fire smelting, and the production and processing cost is greatly affected by the nickel grade of the nickel-iron raw material; for example, if the nickel grade of the nickel-iron raw material is increased from 10% to 16%, the processing cost can be reduced by 5000-7000 yuan / ton of nickel; therefore, the nickel-iron raw material with higher grade has great significance for the production of high nickel matte. The nickel-iron raw material contains rich iron resources, and the conventional fire smelting process only aims to effectively recover the metal nickel therein, and the iron is produced in the form of iron-silicon slag, which has a low sales price, and the iron resources cannot be efficiently utilized. In addition, in the field of wet treatment of nickel-iron raw material, it is generally necessary to go through processes such as grinding, leaching and sulfide impurity removal. The hardness of nickel-iron is large, the grinding efficiency is low, resulting in high grinding cost. After nickel enrichment, the particle size of nickel-iron is small, and the loss is large during the production of high nickel matte by fire method. In addition, sulfides are generally used in the impurity removal process, which consumes a large amount of auxiliary materials, and generates harmful gases such as hydrogen sulfide.

[0025] In order to in-situ increase the nickel grade of the nickel-iron raw material, the present application provides a treatment method of nickel-iron raw material, comprising: The acid leaching process is that the first nickel-iron raw material is contacted with an acidic substance for acid leaching treatment to obtain a leaching solution; the pH value of the leaching solution is 3.0-4.0.

[0026] The displacement process is that the second nickel-iron raw material is subjected to a displacement reaction with the leaching solution to obtain a reaction solution.

[0027] The separation process is that the reaction solution is subjected to a first solid-liquid separation to obtain a nickel-rich solid phase and an iron-containing separation solution.

[0028] After the acid leaching of the nickel-iron raw material, the nickel-iron raw material is reused for displacement reaction, so that the iron in the nickel-iron raw material can be effectively released, and the nickel is retained as much as possible. In this way, the iron in the nickel-iron is extracted by the wet method, and the iron resources in the nickel-iron are effectively developed and utilized, which can be used for the production of ferrous sulfate products in the subsequent process. The present application greatly increases the nickel grade of the nickel-iron raw material, and reduces the cost of the subsequent production of high nickel matte by fire method. In addition, the present application uses the nickel-iron raw material itself for displacement and impurity removal, does not consume other auxiliary materials, is simple to operate, has low cost, does not produce harmful gases such as hydrogen sulfide, and has higher safety.

[0029] As an illustration of the acid leaching treatment, the present application releases part of the nickel and iron in the first nickel-iron raw material through the acid leaching treatment; in some embodiments of the present application, the temperature of the acid leaching treatment is not less than 50°C; optionally, the temperature of the acid leaching treatment is 50-90°C.

[0030] In some embodiments of the present application, in the acid leaching treatment, the first nickel-iron raw material is contacted with the acidic substance in the form of a slurry; as an illustrative example, the acid leaching treatment is performed by adding the acidic substance to the slurry. Optionally, the slurry comprises the first nickel-iron raw material and water; the slurry can be obtained by slurrying the first nickel-iron raw material after adding water. Optionally, the liquid-solid ratio of the water to the first nickel-iron raw material is not less than 3 L:1 kg; optionally, the liquid-solid ratio is 3-5 L:1 kg.

[0031] In some embodiments of the present application, the acid leaching treatment is performed for not less than 4 h; optionally, the acid leaching treatment is performed for 4-15 h, optionally, the acid leaching treatment is performed for 4-10 h or 10-14 h.

[0032] In some embodiments of the present application, the acid leaching treatment comprises adjusting the pH to not more than 3.0 using the acidic substance, optionally, adjusting the pH to 1.0-3.0 using the acidic substance. Further, the acid leaching treatment further comprises, after adding the acidic substance, stabilizing for 0-2 h, and then performing the displacement process after the pH of the slurry is increased to 3.0-4.0. As an illustrative example, the acid leaching treatment comprises, first, slowly adding the acidic substance to control the pH of the slurry of the acid leaching system to not more than 3.0, or to control the pH of the slurry of the acid leaching system to 1.0-3.0. After the addition of the acidic substance is completed, the pH is allowed to increase to 3.0-4.0 naturally after a period of time, and the period of time can be 0-2 h.

[0033] The present application has strict pH requirements for the leaching solution obtained through the acid leaching treatment; in further embodiments of the present application, the pH of the leaching solution is 3.0-4.0.

[0034] In some embodiments of the present application, in the acid leaching treatment, the amount of the acidic substance is controlled according to the theoretical leaching rate of iron of 40-70%. That is, in the leaching treatment, the amount of the acidic substance to be added is the theoretical amount of the acidic substance required for the reaction of 40-70% of the iron in the first nickel-iron raw material with the acidic substance. Through the control of the degree of the acid leaching treatment, on the one hand, the iron in the first nickel-iron raw material can be partially released, and on the other hand, the complete leaching of nickel can be avoided.

[0035] In some embodiments of the present application, the acid used in the acid leaching process comprises at least one of sulfuric acid and hydrochloric acid; further, the acid used in the acid leaching process is sulfuric acid.

[0036] In some embodiments of the present application, the components of the leaching solution include Fe 2+ : 78~105g / L, Fe 3+ : 0.1~0.3g / L, Ni 2+ : 1~7g / L; optionally, the components of the leaching solution further include Co 2+ : 0.1~0.3g / L.

[0037] It should be noted that in the present application, the leaching solution can be a slurry containing part of the solid obtained by contacting the first nickel-iron raw material with the acid, or can be a filtrate obtained by filtering the slurry. When the leaching solution is a slurry containing part of the solid, the components of the leaching solution refer to the detection results of the components of the filtrate after the solid-liquid separation of the slurry; specifically, the leaching solution is obtained after the acid leaching process, and when the leaching solution is detected, the components in the liquid are detected after the solid-liquid separation of the leaching solution; but the leaching solution used in the displacement process can not be subjected to solid-liquid separation.

[0038] In some embodiments of the present application, the mass percentage of Fe in the first nickel-iron raw material and the second nickel-iron raw material is 78~85%, and the mass percentage of Ni is 8~11%; optionally, the components of the first nickel-iron raw material and the second nickel-iron raw material further include Co, and optionally, the mass percentage of Co is 0.3%~0.5%; optionally, the components of the first nickel-iron raw material and the second nickel-iron raw material are the same, and the first nickel-iron raw material and the second nickel-iron raw material can be the same material used in different processes, but the particle size of the first nickel-iron raw material and the second nickel-iron raw material is different.

[0039] In some embodiments of the present application, the particle size D100 of the first nickel-iron raw material is ≤3cm; optionally, the particle size D80 is ≤5mm; optionally, the particle size D10 is ≥1mm; optionally, the second nickel-iron raw material is in powder form, and the particle size of the second nickel-iron raw material is smaller than that of the first nickel-iron raw material; optionally, the particle size D80 of the second nickel-iron raw material is ≤180μm; optionally, the particle size D100 is ≤210μm.

[0040] It is to be understood that, in the field of nickel-iron wet processing, generally, processes such as grinding, leaching, and sulfide removal are needed, the hardness of nickel-iron is large, the grinding efficiency is low, the equipment is greatly worn, and the grinding cost is high. However, in the present application, the particle size of the first nickel-iron raw material does not need to be too fine. If it is too fine, not only is it easy to cause excessive dissolution of nickel in the process of acid leaching, but also it is easy to affect the in-situ growth of nickel ions in the displacement process. Therefore, the present application can overcome the technical defects of the prior art which requires a large amount of fine grinding material, and the present application is conducive to improving the nickel grade without the need for a large amount of fine grinding of the first nickel-iron raw material. The present application at most only grinds for the purpose of obtaining the second nickel-iron raw material. Specifically, since the first nickel-iron raw material does not need to be broken into fine powder, the metal dust pollution is small, the grinding cost is low, the obtained nickel-rich solid phase has large particle size, and the loss of nickel is small when producing high-ice nickel by fire method.

[0041] In some embodiments of the present application, the mass ratio of the first nickel-iron raw material to the second nickel-iron raw material is 5-20:1; optionally, the first nickel-iron raw material is directly subjected to the acid leaching treatment to obtain the leaching solution; that is, the first nickel-iron raw material does not need to be subjected to other treatments or grinding before the acid leaching treatment, and does not need to be in the form of fine powder.

[0042] In some embodiments of the present application, the temperature of the displacement reaction is 60-90℃; optionally, the time length of the displacement reaction is not less than 2h, and optionally, the time length of the displacement reaction is 2-6h; the time of the displacement reaction is the reaction time after the addition of the second nickel-iron raw material; during the displacement reaction, the elemental iron in the second nickel-iron raw material and Ni 2+ , Co 2+ , etc. in the leaching solution undergo displacement reaction to generate elemental Ni and Co, thereby promoting the regrowth of elemental nickel; by performing the displacement reaction, the present application only uses the raw material itself in the impurity removal process, does not consume other auxiliary materials, does not produce H2S harmful gas, and is simple, safe and low in cost.

[0043] In some embodiments of the present application, the first solid-liquid separation method includes centrifugal separation; that is, the reaction liquid is subjected to centrifugal separation, and then the nickel-rich solid phase and the iron-containing separation solution are collected respectively; optionally, the acid leaching process and the displacement process are both carried out in a leaching and impurity removal container, a centrifugal device is arranged below the leaching and impurity removal container, and the reaction liquid can directly enter the centrifugal device from the leaching and impurity removal container, so as to perform the centrifugal separation of the reaction liquid without the need for pump conveying, thereby avoiding the blockage of pipelines or damage to the impeller of the conveying pump by large particles. Arranging the centrifugal device below the leaching and impurity removal container can further ensure that the first nickel-iron raw material does not need to be broken into fine powder, and avoid the limitation of the particle size of the nickel-iron raw material by pipeline pumping.

[0044] In some embodiments of the present application, the pH value of the reaction solution is 4.0-6.0; that is, after the displacement reaction is completed, the pH value will rise to 4.0-6.0. Further, the pH value of the reaction solution is 5.0-6.0. Further, in the separation process, before the first solid-liquid separation is performed, the pH value of the reaction solution is adjusted back to 3.0-4.0. By first performing the displacement reaction and controlling the pH value of the displacement reaction within a suitable range, the present application is conducive to reducing the content of nickel and controlling the content of impurities. The adjustment of the pH value after the displacement reaction can slow down the oxidation speed of ferrous iron; it should be noted that too low pH value will affect the product quality, and too high pH value will cause poor stability of ferrous ions.

[0045] In some embodiments of the present application, the total process time of the adjustment and the first solid-liquid separation is not more than 0.5 h. It should be noted that the total process time refers to the total time consumed from the beginning of the adjustment of the pH value of the reaction solution by adding the acidic substance to the completion of the solid-liquid separation of the reaction solution. Alternatively, the acidic substance used in the adjustment is the same as the acidic substance used in the acid leaching process. In a specific case, from the beginning of the adjustment of the pH value of the reaction solution by adding the acidic substance to the adjustment of the pH value of the reaction solution to 3.0-4.0, and the introduction of the reaction solution after the adjustment of the pH value into a centrifugal device to complete the first solid-liquid separation, the total time consumed is not more than 0.5 h. It should be noted that too long total process time of the adjustment and the first solid-liquid separation will affect the product quality.

[0046] In some embodiments of the present application, in the nickel-rich solid phase, the mass percentage of iron is 67.60-70.55%, the mass percentage of nickel is 15.46-16.19%, and other components are 13.76-16.21% (other components may include multiple elements such as silicon, calcium, magnesium, chromium, oxygen, etc.); alternatively, in the nickel-rich solid phase, the mass percentage of water is 5-15%. In the present application, the nickel-rich solid phase can be directly used to produce high-grade nickel, and the production cost is greatly reduced.

[0047] In some embodiments of the present application, the treatment method further comprises a value adjustment process: adjusting the pH value of the iron-containing separation solution to 1.5-2.5, further to 2.2; alternatively, the acidic substance used in the value adjustment process is the same as the acidic substance used in the acid leaching process, so as to avoid the incorporation of other impurity anions.

[0048] In some embodiments of the present application, the treatment method further comprises a fine filtration process: the iron-containing separation solution is subjected to a second solid-liquid separation to obtain a ferrous sulfate solution; alternatively, the second solid-liquid separation comprises a filtration separation.

[0049] Alternatively, the components of the ferrous sulfate solution include Fe2+ 80~110g / L, Fe 3+ 0.1~1g / L, Ni 2+ 2~35 mg / L; Optionally, the ferrous sulfate solution may also include Co. 2+ The concentration of ferrous sulfate is 0.5~5 mg / L. The ferrous sulfate solution can be used directly or sold externally, or it can be made into ferrous sulfate crystals for external sale.

[0050] In some embodiments of the present invention, the processing method further includes a crystallization step: evaporating the ferrous sulfate solution to crystallize and obtain ferrous sulfate crystals.

[0051] See Figure 1 To understand this, in some embodiments of the present invention, in order to obtain ferrous sulfate and simultaneously improve the nickel grade based on ferric nickel raw materials, the present invention leaches the first ferric nickel raw material (without abrasive) with sulfuric acid, then adds abrasive to obtain a second ferric nickel raw material, which undergoes a displacement reaction. After sequentially performing pH adjustment and a first solid-liquid separation, a nickel-rich solid phase with a higher nickel grade is obtained, along with a high-purity iron-containing separation liquid. Subsequently, sulfuric acid is used to adjust the pH value of the iron-containing separation liquid, and a ferrous sulfate solution is obtained after a second solid-liquid separation. The ferrous sulfate solution is then crystallized to obtain ferrous sulfate crystals.

[0052] See Figure 2 In addition, the present invention provides a processing device for nickel-iron raw materials, the processing device comprising: a feeding unit, a leaching and impurity removal unit, a nickel-iron separation unit, and a control unit.

[0053] The feeding unit includes a first nickel-iron raw material feeding component, a second nickel-iron raw material feeding component, and an acidic substance feeding component.

[0054] The leaching and impurity removal unit includes a leaching and impurity removal container and a first pH monitoring module disposed thereon, and the leaching and impurity removal unit is connected to the feeding unit.

[0055] Optionally, the leaching and impurity removal container includes a leaching and impurity removal tank; optionally, the bottom of the leaching and impurity removal tank is conical; optionally, the leaching and impurity removal unit further includes a suction assembly for suctioning the tail gas generated during the reaction process in the leaching and impurity removal container; optionally, the leaching and impurity removal unit further includes a post-treatment assembly connected to the suction assembly for receiving and treating the tail gas in the suction assembly.

[0056] The nickel-iron separation unit is connected with the discharge port of the leaching impurity removal unit; optionally, the leaching impurity removal unit and the nickel-iron separation unit are arranged in an up-down mode; optionally, the nickel-iron separation unit comprises a centrifugal device, which can be a centrifuge; optionally, the centrifugal device is arranged below the leaching impurity removal container and is arranged in an openable and closable up-down communication mode with the leaching impurity removal container; in particular, the leaching impurity removal container is provided with a bottom valve, and the communication state between the leaching impurity removal container and the centrifugal device is controlled by opening and closing the bottom valve.

[0057] The control unit is configured to control the start and stop of the second nickel-iron raw material feeding assembly according to the data input by the first pH monitoring module; optionally, the control unit is used to realize the nickel-iron raw material processing method as described in any of the above.

[0058] Optionally, the configuration of the control unit further comprises: before controlling the second nickel-iron raw material feeding assembly to feed, controlling the start and stop of the acidic substance feeding assembly according to preset acid leaching data; optionally, the acid leaching data comprises the feeding amount of the acidic substance.

[0059] Optionally, the configuration of the control unit further comprises: after controlling the second nickel-iron raw material feeding assembly to complete feeding, controlling the start and stop of the acidic substance feeding assembly according to the data input by the first pH monitoring module.

[0060] Optionally, the configuration of the control unit further comprises: controlling the start and stop of the nickel-iron separation unit according to the callback start time data monitored by the time monitoring unit; the callback start time is the time when the control of the acidic substance feeding assembly starts after the second nickel-iron raw material feeding assembly completes feeding.

[0061] In some embodiments of the present application, the processing device further comprises a value adjusting unit, the value adjusting unit comprises a value adjusting container and a second pH monitoring module arranged thereon, and the value adjusting unit is connected with the liquid outlet of the nickel-iron separation unit; optionally, the value adjusting container comprises a value adjusting tank.

[0062] In some embodiments of the present application, the processing device further comprises a fine filtration unit, the fine filtration unit is connected with the discharge port of the value adjusting unit; optionally, the fine filtration unit comprises a precision filter.

[0063] In some embodiments of the present application, the processing device further comprises a crystallization unit, the crystallization unit is connected with the liquid outlet of the fine filtration unit; in some other embodiments of the present application, the processing device further comprises a finished product collecting unit, the finished product collecting unit is connected with the liquid outlet of the fine filtration unit; optionally, the finished product collecting unit comprises a finished product tank.

[0064] In some embodiments of the present application, the processing device further comprises a time monitoring unit, which is electrically connected with the nickel-iron separation unit.

[0065] The present application will be described in detail below with reference to specific cases: Example 1 In this embodiment, the processing method of the nickel-iron raw material is as follows: (1) Acid leaching process: 6 kg of low-nickel point nickel-iron raw material (denoted as the first nickel-iron raw material, D100=3 cm, D80=5 mm, D10=1 mm) with a nickel content of 8%, an iron content of 85%, and a cobalt content of 0.3% is taken into a reaction kettle, slurried by adding water according to a liquid-solid ratio of 5:1 (L:kg), and then slowly added with 6.39 kg of sulfuric acid for leaching according to a theoretical leaching rate of iron of 70%. The pH value during the sulfuric acid leaching process is maintained at 1.0, the leaching temperature is kept at 90°C, and the sulfuric acid leaching time is 15 h.

[0066] After the sulfuric acid is added and stabilized for 2 h, the slurry pH value is raised to 3.0, and the leaching solution (leaching slurry) is obtained; the composition of the leaching solution is detected by sampling and filtering, and the detection results are as follows: Fe 2+ =105 g / L, Fe 3+ =0.3 g / L, Ni 2+ =7 g / L, Co 2+ =0.3 g / L.

[0067] (2) Replacement process: 1200 g of low-nickel point nickel-iron powder (denoted as the second nickel-iron raw material, with the same composition as the first nickel-iron raw material, D100=210 um, D80=180 um) is slowly added into the leaching solution for replacement and impurity removal. The reaction temperature for replacement and impurity removal is 90°C, and after the second nickel-iron raw material is added, the reaction is carried out for 6 h to obtain a reaction solution (reaction slurry), and the pH value of the reaction solution is 5.5.

[0068] (3) Separation process: a small amount of sulfuric acid is added to the reaction solution to adjust the pH value to 3.0, and the centrifugal separation is carried out within 0.5 h (total time for adjustment + separation) to obtain a nickel-rich solid phase and an iron-containing separation solution.

[0069] In this embodiment, the composition detection results of the nickel-containing solid phase (nickel-rich solid phase) are as follows: Ni=15.69%, Fe=70.55%, other impurities=13.76%, and moisture=15%; and the natural basis mass of the nickel-containing solid phase is 4.31 kg.

[0070] (4) Value adjustment process: an appropriate amount of sulfuric acid is added to the iron-containing separation solution to adjust the pH value to 2.2.

[0071] (5) Precision filtration process: the iron-containing separation solution after the value adjustment process is subjected to precision filtration to obtain a refined ferrous sulfate solution.

[0072] The component detection result of the refined ferrous sulfate solution in this embodiment is: Fe 2+ = 110 g / L, Fe 3+ = 0.5 g / L, Ni 2 + = 35 mg / L, Co 2+ = 5 mg / L; the volume of the refined ferrous sulfate solution is 32 L.

[0073] Embodiment 2 In this embodiment, the processing method of the nickel-iron raw material is as follows: (1) Acid leaching process: 6 kg of low-nickel point nickel-iron raw material (denoted as first nickel-iron raw material, D100 = 3 cm, D80 = 5 mm, D10 = 1 mm) with a nickel content of 9%, an iron content of 82%, and a cobalt content of 0.4% is taken into a reaction kettle, and water is added for slurry according to a liquid-solid ratio of 4.5:1 (L:kg), then 5.29 kg of sulfuric acid is slowly added for leaching according to a theoretical iron leaching rate of 60%, the pH value is maintained at about 2.0 during the sulfuric acid leaching process, the leaching temperature is maintained at about 60°C, and the sulfuric acid leaching time is 10 h.

[0074] After the sulfuric acid is added and stabilized for 2.0 h, the slurry pH value rises to 4.0, and the leaching solution is obtained; the components of the leaching solution are detected by sampling and filtering, and the detection result is: Fe 2+ = 98 g / L, Fe 3+ = 0.3 g / L, Ni 2+ = 4 g / L, Co 2+ = 0.2 g / L.

[0075] (2) Replacement process: 600 g of low-nickel point nickel-iron powder (denoted as second nickel-iron raw material, with the same composition as the first nickel-iron raw material, D100 = 210 um, D80 = 180 um) is slowly added into the leaching solution for replacement and impurity removal, the replacement and impurity removal reaction temperature is 60°C, after the second nickel-iron raw material is added, the reaction is carried out for 4 h, and the reaction liquid is obtained, and the pH value of the reaction liquid is 6.0.

[0076] (3) Separation process: sulfuric acid is added to the reaction liquid to adjust the slurry pH value to 4.0, and the slurry is centrifugally separated within 0.5 h (total time of adjustment + separation) to obtain a nickel-containing solid phase and an iron-containing separation liquid.

[0077] In this embodiment, the component detection result of the nickel-containing solid phase is: Ni = 16.19%, Fe = 67.60%, other impurities = 16.21%, and moisture = 13%; the mass of the nickel-containing solid phase is 4.21 kg.

[0078] (4) Value adjustment process: an appropriate amount of sulfuric acid is added to the iron-containing separation liquid to adjust the pH value to 1.5.

[0079] (5) Fine filtering process: fine filtering the iron-containing separation liquid after the adjusting process to obtain a refined ferrous sulfate solution.

[0080] In this embodiment, the component detection result of the refined ferrous sulfate solution is: Fe 2+ = 102 g / L, Fe 3+ = 1 g / L, Ni 2+ = 30 mg / L, Co 2+ = 2 mg / L; the volume of the refined ferrous sulfate solution is 28.5 L.

[0081] Example 3 In this embodiment, the processing method of the nickel-iron raw material is: (1) Acid leaching process: 6 kg of low-nickel point nickel-iron raw material (denoted as the first nickel-iron raw material, D100 = 3 cm, D80 = 5 mm, D10 = 1 mm) with a nickel content of 10%, an iron content of 80%, and a cobalt content of 0.45% is taken into a reaction kettle, slurried by adding water according to a liquid-to-solid ratio of 4.6:1 (L:kg), and then 4.30 kg of sulfuric acid is slowly added for leaching according to a theoretical iron leaching rate of 50%. The pH value is maintained at about 3.0 during the sulfuric acid leaching process, the leaching temperature is maintained at about 50°C, and the sulfuric acid leaching time is 8 h.

[0082] After the sulfuric acid is added and stabilized for 0 h, the leaching solution is obtained; the components of the leaching solution are detected by sampling and filtering, and the detection result is: Fe 2+ = 78 g / L, Fe 3+ = 0.1 g / L, Ni 2+ = 2 g / L, Co 2+ = 0.15 g / L.

[0083] (2) Replacement process: 300 g of low-nickel point nickel-iron powder (denoted as the second nickel-iron raw material, with the same composition as the first nickel-iron raw material, D100 = 210 um, D80 = 180 um) is slowly added to the leaching solution for replacement and impurity removal. The reaction temperature for replacement and impurity removal is 90°C, and after the second nickel-iron raw material is added, the reaction is carried out for 4 h to obtain a reaction liquid. The pH of the reaction liquid is 5.0.

[0084] (3) Separation process: sulfuric acid is added to the reaction liquid to adjust the pH of the slurry to 4.0, and the slurry is centrifugally separated within 0.5 h (total time for adjustment + separation) to obtain a nickel-containing solid phase and an iron-containing separation liquid.

[0085] In this embodiment, the component detection result of the nickel-containing solid phase is: Ni = 15.84%, Fe = 68.32%, other impurities = 15.84%, and moisture = 8%; the mass of the nickel-containing solid phase is 4.32 kg.

[0086] (4) Adjusting process: an appropriate amount of sulfuric acid is added to the iron-containing separation liquid to adjust the pH to 2.2.

[0087] (5) Fine filtering process: fine filtering the iron-containing separation solution after the value adjusting process to obtain a refined ferrous sulfate solution.

[0088] In this embodiment, the component detection result of the refined ferrous sulfate solution is: Fe 2+ = 80 g / L, Fe 3+ = 0.1 g / L, Ni 2+ = 2 mg / L, Co 2+ = 0.5 mg / L; the volume of the refined ferrous sulfate solution is 29 L.

[0089] Example 4 In this embodiment, the processing method of the nickel-iron raw material is: (1) Acid leaching process: 6 kg of low-nickel point nickel-iron raw material (denoted as the first nickel-iron raw material, D100 = 3 cm, D80 = 5 mm, D10 = 1 mm) with a nickel content of 11%, an iron content of 78%, and a cobalt content of 0.50% is taken into a reaction kettle, slurried by adding water according to a liquid-to-solid ratio of 3:1 (L:kg), and then 3.35 kg of sulfuric acid is slowly added for leaching according to a theoretical iron leaching rate of 40%. The pH value is maintained at about 1.0 during the sulfuric acid leaching process, the leaching temperature is maintained at about 80°C, and the sulfuric acid leaching time is 4 h.

[0090] After the sulfuric acid addition is completed and stabilized for 1 h, the slurry pH value is raised to 3.0, and the leaching solution is obtained; the components of the leaching solution are detected by sampling and filtering, and the detection results are: Fe 2+ = 96 g / L, Fe 3+ = 0.2 g / L, Ni 2+ = 1 g / L, Co 2+ = 0.1 / L.

[0091] (2) Replacement process: 300 g of low-nickel point nickel-iron powder (denoted as the second nickel-iron raw material, with the same composition as the first nickel-iron raw material, D100 = 210 um, D80 = 180 um) is slowly added to the leaching solution for replacement and impurity removal. The reaction temperature for replacement and impurity removal is set to 80°C, and after the addition of the second nickel-iron raw material is completed, the reaction is carried out for 2 h to obtain a reaction solution, and the pH of the reaction solution is 4.0.

[0092] (3) Separation process: sulfuric acid is added to the reaction solution to adjust the slurry pH to 3.0, and the slurry is centrifugally separated within 0.5 h (total time for adjustment + separation) to obtain a nickel-containing solid phase and an iron-containing separation solution.

[0093] In this embodiment, the component detection result of the nickel-containing solid phase is: Ni = 15.46%, Fe = 69.07%, other impurities = 15.46%, and moisture = 5%; the mass of the nickel-containing solid phase is 4.72 kg.

[0094] (4) pH adjusting step: adding appropriate amount of sulfuric acid to the iron-containing separation liquid to adjust the pH value to 2.5.

[0095] (5) fine filtering step: fine filtering the iron-containing separation liquid after the pH adjusting step to obtain the refined ferrous sulfate solution.

[0096] In this embodiment, the component detection result of the refined ferrous sulfate solution is: Fe 2+ = 98 g / L, Fe 3+ = 0.3 g / L, Ni 2+ = 5 mg / L, and Co 2+ = 1 mg / L; the volume of the refined ferrous sulfate solution is 18.5 L.

[0097] Comparative Example 1 Compared with Example 1, the only difference is that in the separation step, the pH value is not quickly adjusted, resulting in a high Fe 3+ concentration of 2 g / L in the refined ferrous sulfate solution.

[0098] In this comparative example, the component detection result of the nickel-containing solid phase (nickel-rich solid phase) is: Ni = 15.70%, Fe = 70.54%, other impurities = 13.76%, and moisture = 15%; the natural base mass of the nickel-containing solid phase is 4.31 kg.

[0099] In this comparative example, the component detection result of the refined ferrous sulfate solution is: Fe 2+ = 108.5 g / L, Fe 3+ = 2.0 g / L, Ni 2 + = 30 mg / L, and Co 2+ = 2 mg / L; the volume of the refined ferrous sulfate solution is 32 L.

[0100] Comparative Example 2 Compared with Example 1, the only difference is that in the separation step, after adjusting the pH value, the solid-liquid separation is performed after standing for 2 h, resulting in high Ni 2+ and Co 2+ concentrations in the refined ferrous sulfate solution.

[0101] In this comparative example, the component detection result of the nickel-containing solid phase (nickel-rich solid phase) is: Ni = 15.65%, Fe = 70.61%, other impurities = 13.74%, and moisture = 15%; the natural base mass of the nickel-containing solid phase is 4.31 kg.

[0102] In this comparative example, the component detection result of the refined ferrous sulfate solution is: Fe 2+ = 110 g / L, Fe 3+ = 0.5 g / L, Ni 2 += 100 mg / L, Co 2+ = 35 mg / L; the volume of the refined ferrous sulfate solution was 32 L.

[0103] Comparative Example 3 Compared with Example 1, only the pH value of the sulfuric acid leaching process was adjusted to 0.5 in the present comparative example, and other conditions remained unchanged, resulting in the sulfuric acid leaching time being shortened to 10 h, and the Ni and Co contents in the leachate rising.

[0104] In the present comparative example, the component detection results of the nickel-containing solid phase were as follows: Ni = 11.89%, Fe = 73.88%, other impurities = 14.23%, and moisture = 15%; the natural base mass of the nickel-containing solid phase was 4.11 kg.

[0105] In the present comparative example, the component detection results of the refined ferrous sulfate solution were as follows: Fe 2+ = 110 g / L, Fe 3+ = 0.5 g / L, Ni 2+ = 5 g / L, Co 2+ = 0.2 g / L; the volume of the refined ferrous sulfate solution was 32 L.

[0106] Comparative Example 4 Compared with Example 1, only the particle size of the second nickel-iron raw material was adjusted to D100 = 800 um and D80 = 500 um in the present comparative example, and other conditions remained unchanged.

[0107] In the present comparative example, the component detection results of the nickel-containing solid phase were as follows: Ni = 14.23%, Fe = 71.84%, other impurities = 13.92%, and moisture = 15%; the natural base mass of the nickel-containing solid phase was 4.23 kg.

[0108] In the present comparative example, the component detection results of the refined ferrous sulfate solution were as follows: Fe 2+ = 110 g / L, Fe 3+ = 0.5 g / L, Ni 2 + = 2 g / L, Co 2+ = 0.1 g / L; the volume of the refined ferrous sulfate solution was 32 L.

[0109] In the above technical solution of the present application, the above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the technical concept of the present application, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A process for treating a nickel-iron feed material, characterized by, The application relates to a method for preparing a nickel-rich solution, comprising the following steps: an acid leaching process: a first nickel-iron raw material is contacted with an acidic substance to perform acid leaching treatment, and a leaching solution is obtained; the pH value of the leaching solution is 3.0-4.0; a displacement process: a second nickel-iron raw material is subjected to a displacement reaction with the leaching solution, and a reaction solution is obtained; a separation process: the reaction solution is subjected to a first solid-liquid separation, and a nickel-rich solid phase and an iron-containing separation solution are obtained. The acid leaching treatment at least meets one of the following conditions: A: the temperature of the acid leaching treatment is not lower than 50 DEG C; Optionally, the temperature of the acid leaching treatment is 50-90 DEG C; 2. The treatment method according to claim 1, characterized in that, B: in the acid leaching treatment, the first nickel-iron raw material is contacted with the acidic substance in the form of a slurry solution; Optionally, the slurry solution comprises the first nickel-iron raw material and water; Optionally, the liquid-solid ratio of the water and the first nickel-iron raw material is not less than 3L:1kg; optionally, the liquid-solid ratio is 3-5L:1kg; C: the acid leaching treatment lasts for not less than 4h; Optionally, the acid leaching treatment lasts for 4-15h, and optionally, 4-10h; D: the acid leaching treatment comprises the following steps: the pH value is adjusted to be not higher than 3.0 by using the acidic substance, and optionally, the pH value is adjusted to be 1.0-3.0; E: in the acid leaching treatment, the amount of the acidic substance is controlled according to the theoretical leaching rate of iron being 40-70%; F: the acidic substance used in the acid leaching treatment comprises at least one of sulfuric acid and hydrochloric acid; G: the acid leaching treatment further comprises the following steps: after the addition of the acidic substance is completed, the acid leaching treatment is stabilized for 0-2h, and then the displacement process is performed after the pH value of the leaching solution is increased to 3.0-4.

0. In the first nickel-iron raw material and the second nickel-iron raw material, the mass percentage of Fe is independently 78-85%, and the mass percentage of Ni is independently 8-11%; Optionally, the first nickel-iron raw material and the second nickel-iron raw material further comprise Co; Optionally, the first nickel-iron raw material and the second nickel-iron raw material have the same composition; 3. The treatment method according to claim 1 or 2, characterized in that, The composition of the leachate includes Fe 2+ : 78-105 g / L, Fe 3+ : 0.1-0.3 g / L, Ni 2+ : 1-7 g / L; Optionally, the constituents of the leachate further include Co 2+ : 0.1-0.3 g / L.

4. The treatment method of claim 1, wherein Optionally, the mass ratio of the first nickel-iron raw material to the second nickel-iron raw material is 5-20:1; Optionally, the first nickel-iron raw material is directly subjected to the acid leaching treatment, and the leaching solution is obtained; Optionally, the particle size D100 of the first nickel-iron raw material is less than or equal to 3cm; optionally, the particle size D80 is less than or equal to 5mm; and optionally, the particle size D10 is greater than or equal to 1mm; Optionally, the particle size of the second nickel-iron raw material is smaller than that of the first nickel-iron raw material; optionally, the particle size D80 of the second nickel-iron raw material is less than or equal to 180mu m; and optionally, the particle size D100 is less than or equal to 210mu m; Optionally, the temperature of the displacement reaction is 60-90 DEG C; Optionally, the displacement reaction lasts for not less than 2h, and optionally, 2-6h; Optionally, the first solid-liquid separation is achieved by centrifugal separation; Optionally, the pH value of the reaction solution is 4.0-6.0, and further, the pH value of the reaction solution is 5.0-6.

0. In the separation process, before the first solid-liquid separation is performed, the pH value of the reaction solution is adjusted back to 3.0-4.

0. The total process time of the adjustment and the first solid-liquid separation is not higher than 0.5h. ​ 5. The treatment method of claim 1, wherein ​ 6. The treatment method according to claim 5, characterized in that, ​ Optionally, the acidic substance used in the callback is the same as the acidic substance used in the acid leaching process.

7. The treatment method according to any one of claims 4 to 6, characterized in that, In the nickel-rich solid phase, the mass percentage of iron is 67.60-70.55%, the mass percentage of nickel is 15.46-16.19%, and the mass percentage of other components is 13.76-16.21% without considering moisture; Optionally, in the nickel-rich solid phase, the mass percentage of moisture is 5-15%.

8. The treatment method of claim 1, wherein, The treatment method further comprises a value adjustment process: adjusting the pH value of the iron-containing separation liquid to 1.5-2.5; Optionally, the acidic substance used in the value adjustment process is the same as the acidic substance used in the acid leaching process; Optionally, the treatment method further comprises a fine filtration process: the iron-containing separation liquid is subjected to a second solid-liquid separation to obtain a ferrous sulfate solution; Optionally, the second solid-liquid separation comprises filtration separation; Optionally, the composition of the ferrous sulfate solution includes Fe 2+ : 80-110 g / L, Fe 3+ : 0.1-1 g / L, Ni 2+ : 2-35 mg / L; Optionally, the ingredients of the ferrous sulfate solution further include Co 2+ : 0.5~5mg / L; Optionally, the treatment method further comprises a crystallization process: the ferrous sulfate solution is evaporated and crystallized to obtain ferrous sulfate crystals.

9. A device for processing a nickel-iron feed material, characterized by The treatment device comprises: a feeding unit, which comprises a first nickel-iron raw material feeding assembly, a second nickel-iron raw material feeding assembly, and an acidic substance feeding assembly; a leaching and impurity removal unit, which comprises a leaching and impurity removal container and a first pH monitoring module arranged thereon, and is connected with the feeding unit; a nickel-iron separation unit, which is connected with a discharge port of the leaching and impurity removal unit; a control unit, which is configured to control the start and stop of the second nickel-iron raw material feeding assembly according to data input by the first pH monitoring module.

10. The processing device of claim 9, wherein, The treatment device further comprises a value adjustment unit, which comprises a value adjustment container and a second pH monitoring module arranged thereon, and is connected with a liquid outlet of the nickel-iron separation unit; Optionally, the treatment device further comprises a fine filtration unit, which is connected with a discharge port of the value adjustment unit; Optionally, the treatment device further comprises a crystallization unit, which is connected with a liquid outlet of the fine filtration unit; Optionally, the treatment device further comprises a time monitoring unit, which is electrically connected with the nickel-iron separation unit; Optionally, the configuration of the control unit further comprises one or more of the following: a: before controlling the second nickel-iron raw material feeding assembly to feed, controlling the start and stop of the acidic substance feeding assembly according to preset acid leaching data; Optionally, the acid leaching data comprises the amount of acidic substance to be added; b: after controlling the second nickel-iron raw material feeding assembly to complete feeding, controlling the start and stop of the acidic substance feeding assembly according to data input by the first pH monitoring module; c: controlling the start and stop of the nickel-iron separation unit according to callback start time data monitored by the time monitoring unit; the callback start time is the time when the acidic substance starts to be fed after the second nickel-iron raw material feeding assembly completes feeding.

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