Method for treating nickel sulfate solution
By using a combination of nickel-based neutralizers and nickel precipitate materials in nickel sulfate solution, the problems of pipeline blockage and complex processing caused by calcium impurities introduced during the neutralization and impurity removal of nickel sulfate solution are solved, achieving efficient high-grade nickel matte production and low-cost processing.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- GUANGXI CNGR NEW ENERGY SCI & TECH CO LTD
- Filing Date
- 2025-11-27
- Publication Date
- 2026-06-04
Smart Images
Figure CN2025138300_04062026_PF_FP_ABST
Abstract
Description
Treatment methods for nickel sulfate solutions Cross-reference to related applications
[0001] This application claims priority to Chinese Patent Application No. 202411746019.0, filed on November 29, 2024, entitled “Method for processing nickel sulfate solution”, the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of non-ferrous metal smelting technology, and in particular to a method for processing nickel sulfate solution. Background Technology
[0003] In related technologies, the neutralization and impurity removal of nickel sulfate solution generally involves using calcium powder to adjust the pH value, which further introduces calcium impurities and can easily cause problems such as calcium saturation precipitation and blockage of pipelines during liquid transfer processes.
[0004] In addition, the nickel-iron intermediates produced by neutralization and impurity removal are generally recovered by acid washing, value adjustment and impurity removal, and solid-liquid separation. Open-circuit impurities are difficult to handle, the process is complicated, there is an internal circulation problem of impurities, and the impurity removal residue is hazardous waste with high treatment costs. Summary of the Invention
[0005] One of the purposes of this application is to provide a method for treating nickel sulfate solution, which aims to solve the problem that existing processes for neutralizing and removing impurities from nickel sulfate solution introduce calcium impurities and generate hazardous waste during nickel recovery.
[0006] To achieve the above objectives, this application provides a method for processing nickel sulfate solution, comprising:
[0007] In the neutralization process, a nickel-based neutralizing agent is added to the nickel sulfate solution to remove impurities, resulting in a first solution and a first solid.
[0008] In the extraction and degreasing process, the first solution is extracted and degreased using nickel soap to obtain a degreased solution.
[0009] In the electrowinning process, the degreasing solution is electrowinning to obtain anolyte and electrowinning nickel plate;
[0010] In the nickel plating process, sodium hydroxide and / or sodium carbonate are added to the anolyte, and after precipitation, nickel plating material is obtained; the nickel plating material is used as a nickel-based neutralizing agent.
[0011] In some embodiments, it also includes:
[0012] The pickling process involves pickling the first solid and separating the solid and liquid to obtain a second solution and a second solid.
[0013] In the smelting process, the second solid is smelted with a sulfiding agent and a reducing agent in an oxygen-containing atmosphere to obtain high-grade nickel matte.
[0014] In some embodiments, at least one of the following conditions is met:
[0015] A. The nickel content in the second solid is 10%-20%;
[0016] B. The mass ratio of the second solid to sulfur in the vulcanizing agent and reducing agent is 1:(0.03-0.04):(0.08-0.12);
[0017] C. The vulcanizing agent is sulfur or a sulfide;
[0018] D. The reducing agent is coke powder, bituminous coal, or anthracite;
[0019] E. At least 80 wt% of the reducing agent must pass through an 80-mesh sieve;
[0020] F. Melting temperature is 1200℃-1600℃;
[0021] G. The composition of high-grade nickel matte includes: Ni 60%-73%, Co 1%-2%, Cu 3%-8%, Fe 4-10%, S 18%-23%;
[0022] H. The composition of nickel sulfate solution includes Ni 60-120 g / L, Co 3-21 g / L, Mn 3-21 g / L, Cu 0.1-3 g / L, Cr 100-300 mg / L, Fe 500-2000 mg / L, Al 300-1000 mg / L, Si 100-1000 mg / L, Ca 100-600 mg / L, and Mg 1-6.5 g / L.
[0023] In some embodiments, the extraction and degreasing process includes:
[0024] In the first saponification step, the first extractant is saponified with the nickel immersion material to obtain a first nickel soap organic phase;
[0025] In the first extraction step, the first solution is contacted with the first nickel soap organic phase for extraction to obtain a third solution;
[0026] In the first degreasing step, the third solution is brought into contact with the nickel plating material to remove oil, resulting in a fourth solution and a third solid.
[0027] In some embodiments, the oil removal process further includes:
[0028] The second saponification step involves saponifying the second extractant with the nickel precipitate to obtain a second nickel soap organic phase.
[0029] In the second extraction step, the fourth solution is contacted with the second nickel soap organic phase for extraction to obtain the fifth solution;
[0030] In the second degreasing step, the fifth solution is brought into contact with the nickel plating material to remove oil, resulting in a sixth solution and a fourth solid, wherein the sixth solution is the degreasing solution.
[0031] In some embodiments, the nickel immersion material saponified with the first extractant includes the third solid; the nickel immersion material saponified with the second extractant includes the fourth solid.
[0032] In some embodiments, at least one of the following conditions is met:
[0033] A. The saponification temperature is 45-65℃;
[0034] B. The first extractant was selected from P204;
[0035] C. The second extractant is selected from P507;
[0036] D. The nickel content in the organic phase of the second nickel soap and the organic phase of the first nickel soap are independently 6-12 g / L.
[0037] In some embodiments, at least one of the following conditions is met:
[0038] A. The oil content of the fourth and sixth solutions is ≤5 mg / L;
[0039] B. The fifth solution contains the following components: Ni 70-120 g / L, Co 5-24 mg / L, Mn 0.01-2 mg / L, Cu 0.01-2 mg / L, Cr ≤1 mg / L, Fe 0.01-1 mg / L, Al 0.1-1 mg / L, Si 20-50 mg / L, Ca 0.1-3 mg / L, Mg 1-300 mg / L, and oil 10-50 mg / L.
[0040] In some embodiments, at least one of the following conditions is met:
[0041] A. The pH value during the impurity removal process is 4.0-6.0;
[0042] B. The temperature for the impurity removal process is 65-80℃;
[0043] C. The dry weight (t) of the nickel-based neutralizing agent: the volume (m3) of the nickel sulfate solution = 1:60-300;
[0044] D. The components of the first solution include: Ni 65~110g / L, Co 3~20g / L, Mn 3~20g / L, Cu 0.1~2g / L, Cr 1~50mg / L, Fe 0.1~50mg / L, Al 1~50mg / L, Si 20~80mg / L, Ca 100~550mg / L, Mg 1~6g / L;
[0045] E. The first solids include: nickel hydroxide, iron-silicon-aluminum precipitate, and manganese dioxide.
[0046] In some embodiments, the preparation method of nickel sulfate solution includes: leaching nickel hydroxide with acid and anolyte.
[0047] Compared with the prior art, the beneficial effects of this application include:
[0048] The nickel sulfate solution treatment method provided in this application includes a neutralization process, an extraction and degreasing process, an electrowinning process, and a nickel precipitation process. In the neutralization process, the nickel precipitate produced from the anolyte precipitation in the nickel precipitation process is used as a neutralizing agent to adjust the pH value. The neutralized and impurity-removed solution is then subjected to extraction, degreasing, and electrowinning to obtain the anolyte. The anolyte continues to precipitate to obtain the nickel precipitate. The first solid produced by the nickel sulfate solution treatment method of this application can be used for pyrometallurgical production of high-grade nickel matte. Some impurities in the electrowinning process and raw materials can be discharged from the system through the first solid, resulting in no hazardous waste residue. This reduces the number of filter presses required, the number of solid residue filtrations, and the workload of slag unloading. Since the neutralization process does not use calcium powder for neutralization, the problem of saturated calcium precipitation clogging the pipeline is reduced. Attached Figure Description
[0049] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.
[0050] Figure 1 is a schematic flowchart of an embodiment of the nickel sulfate solution treatment method of this application;
[0051] Figure 2 is a schematic flowchart of another embodiment of the nickel sulfate solution treatment method of this application. Detailed Implementation
[0052] As used in this article:
[0053] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.
[0054] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.
[0055] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.
[0056] In these embodiments, wt% refers to weight percentage, and unless otherwise specified, all percentages are by mass.
[0057] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.
[0058] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).
[0059] In this application, nickel cobalt hydroxide (MHP) refers to a nickel intermediate that can be prepared by acid leaching, impurity removal, precipitation and other nickel-containing waste materials from laterite nickel ore, sulfide ore and other nickel-containing waste materials. Depending on the source, nickel cobalt hydroxide contains nickel (Ni) and may contain metallic elements such as cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), aluminum (Al), calcium (Ca), magnesium (Mg) and copper (Cu).
[0060] In this related technology, the neutralization and impurity removal of nickel sulfate solution generally involves adjusting the pH value with calcium powder. This step introduces calcium impurities, which can easily cause calcium saturation precipitation during processes such as liquid transfer, leading to pipe blockage.
[0061] In addition, the nickel-iron intermediates produced by neutralization and impurity removal are generally recovered by acid washing, value adjustment and impurity removal, and solid-liquid separation. This method is complex and has the problem of internal circulation of impurities. Moreover, the impurity removal residue is hazardous waste and has high treatment costs.
[0062] In view of the aforementioned problems, this application provides a method for processing nickel sulfate solution, as shown in Figure 1, including:
[0063] S100: Neutralization process, adding a nickel-based neutralizing agent to a nickel sulfate solution to remove impurities, resulting in a first solution and a first solid;
[0064] S200: Extraction and degreasing process, in which the first solution is extracted and degreased with nickel soap to obtain a degreased solution;
[0065] S300: Electrowinning process, in which the degreasing solution is electrowinning to obtain anolyte and electrowinning nickel plate;
[0066] S400: Nickel immersion process, sodium hydroxide and / or sodium carbonate are added to the anolyte, and nickel immersion material is obtained after precipitation; nickel immersion material is used as a nickel-based neutralizer.
[0067] The nickel sulfate solution treatment method provided in this application includes a neutralization process, an extraction and degreasing process, an electrowinning process, and a nickel precipitation process. In the neutralization process, the nickel precipitate produced from the anolyte precipitation in the nickel precipitation process is used as a neutralizing agent to adjust the pH value. The neutralized and impurity-removed solution is then subjected to extraction, degreasing, and electrowinning to obtain the anolyte. The anolyte continues to precipitate to obtain the nickel precipitate. The first solid produced by the nickel sulfate solution treatment method of this application can be used for pyrometallurgical production of high-grade nickel matte. Some impurities in the electrowinning process and raw materials can be discharged from the system through the first solid, resulting in no hazardous waste residue. This reduces the number of filter presses required, the number of solid residue filtrations, and the workload of unloading. Since the neutralization process does not use calcium powder for neutralization, the problem of saturated calcium precipitation clogging the pipeline is reduced.
[0068] The nickel sulfate solution in S100 can be obtained by dissolving nickel cobalt hydroxide (MHP) in sulfuric acid. It is understood that the nickel sulfate solution in S100 can also be obtained by dissolving nickel raw materials such as nickel cobalt sulfide, nickel powder, and nickel-containing waste in sulfuric acid, or by dissolving high-grade nickel matte in sulfuric acid to preliminarily remove iron. The nickel sulfate solution also contains unreacted sulfuric acid.
[0069] Optionally, the preparation method of the nickel sulfate solution of this application includes: leaching nickel hydroxide with acid and anolyte. Exemplarily, the composition of the nickel sulfate solution includes Ni 60-120 g / L, Co 3-21 g / L, Mn 3-21 g / L, Cu 0.1-3 g / L, Cr 100-300 mg / L, Fe 500-2000 mg / L, Al 300-1000 mg / L, Si 100-1000 mg / L, Ca 100-600 mg / L, and Mg 1-6.5 g / L.
[0070] In some embodiments, the pH value of the impurity removal process in step S100 is 4.0-6.0, for example, it can be any value between 4.0, 4.2, 4.5, 4.7, 4.9, 5.0, 5.3, 5.5, 5.8, 6.0, or 4.0-6.0. The temperature of the impurity removal process is 65-80°C, for example, it can be any value between 65°C, 70°C, 75°C, 80°C, or 65-80°C.
[0071] In some embodiments, the impurity removal process in step S100 includes: adding a nickel-based neutralizing agent to neutralize the nickel sulfate solution at a ratio of nickel-based neutralizing agent dry basis mass (t): nickel sulfate solution volume (m3) = 1:60~300 to obtain a first solution and a first solid.
[0072] In some embodiments, the first solution obtained in step S100 comprises: Ni 65-110 g / L, Co 3-20 g / L, Mn 3-20 g / L, Cu 0.1-2 g / L, Cr 1-50 mg / L, Fe 0.1-50 mg / L, Al 1-50 mg / L, Si 20-80 mg / L, Ca 100-550 mg / L, and Mg 1-6 g / L. The first solid comprises: nickel hydroxide, iron-silicon-aluminum precipitate, and manganese dioxide.
[0073] In some embodiments, the S200 extraction and degreasing process includes:
[0074] S210: First saponification step, the first nickel soap organic phase obtained by saponifying the first extractant with the nickel immersion material;
[0075] S220: First extraction step, the first solution is contacted with the first nickel soap organic phase for extraction to obtain the third solution;
[0076] S230: The first degreasing step involves contacting the third solution with the nickel plating material to remove oil, resulting in a fourth solution and a third solid.
[0077] In the above embodiments, the third solid includes nickel plating material and extractant adsorbed by the nickel plating material.
[0078] In some embodiments, step S230 is followed by:
[0079] S240: Second saponification step, the second extractant is saponified with the nickel immersion material to obtain the second nickel soap organic phase;
[0080] S250: The second extraction step involves contacting the fourth solution with the second nickel soap organic phase for extraction to obtain the fifth solution;
[0081] S260: The second degreasing step involves contacting the fifth solution with the nickel plating material to remove oil, resulting in a sixth solution and a fourth solid. The sixth solution is the degreasing solution.
[0082] In the above embodiments, the fourth solid includes nickel plating material and extractant adsorbed by the nickel plating material.
[0083] The extraction residue contains a certain amount of oil (including extractant), which needs to be removed before the electrowinning process. The most common oil removal method in related technologies is activated carbon degreasing. Although activated carbon can remove oil, it requires a large amount of activated carbon, resulting in high regeneration costs. Moreover, the activated carbon (containing extractant) after oil removal is classified as hazardous solid waste, and its disposal costs are high. In this application embodiment, nickel precipitate is used for oil removal, eliminating the production of activated carbon solid waste. The nickel precipitate after oil adsorption is returned to saponification, achieving extractant recovery and avoiding extractant loss.
[0084] In the above embodiments, there are various ways to remove oil by contacting the third solution with the nickel immersion material. For example, the third solution can be mixed with the nickel immersion material for oil removal, or the third solution can be passed through a filter cake containing the nickel immersion material for oil removal. Similarly, there are also various ways to remove oil by contacting the fifth solution with the nickel immersion material. For example, the fifth solution can be mixed with the nickel immersion material for oil removal, or the fifth solution can be passed through a filter cake containing the nickel immersion material for oil removal.
[0085] In some embodiments, the nickel immersion material saponified with the first extractant in step S210 includes a third solid; the nickel immersion material saponified with the second extractant in step S240 includes a fourth solid. It is understood that the inclusion of a third solid in the nickel immersion material saponified with the first extractant in step S210 means that the third solid serves as a raw material for providing the nickel immersion material and participates in the first saponification step. Similarly, the inclusion of a fourth solid in the nickel immersion material saponified with the second extractant in step S240 means that the fourth solid serves as a raw material for providing the nickel immersion material and participates in the second saponification step.
[0086] The saponification process utilizes the nickel plating material in S400, the third solid, or the fourth solid to react directly with the extractant. The process is simple, leaves almost no residual solids after saponification, requires no filtration, and requires minimal equipment investment. When using the third or fourth solid to prepare the organic phase of nickel soap with the extractant, the extractant contained in the third and fourth solids can be recovered, resulting in almost no extractant loss in this step.
[0087] In some embodiments, the saponification temperature is 45-65°C, for example, it can be any value between 45°C, 50°C, 55°C, 60°C, 65°C, or 45-65°C. It is understood that the saponification temperature refers to the temperature of the first saponification step and the second saponification step.
[0088] In some embodiments, the first extractant is selected from P204; the second extractant is selected from P507.
[0089] In some embodiments, the nickel content in the second nickel soap organic phase and the first nickel soap organic phase are independently 6-12 g / L, for example, it can be any value between 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L or 6-12 g / L.
[0090] In some embodiments, the oil content of the fourth solution obtained in step S230 and the sixth solution obtained in step S260 is ≤5 mg / L, for example, it can be any value of 1 mg / L, 2 mg / L, 3 mg / L, 4 mg / L, 5 mg / L or ≤5 mg / L.
[0091] In some embodiments, the fifth solution in step S250 comprises: Ni 70-120 g / L, Co 5-24 mg / L, Mn 0.01-2 mg / L, Cu 0.01-2 mg / L, Cr ≤1 mg / L, Fe 0.01-1 mg / L, Al 0.1-1 mg / L, Si 20-50 mg / L, Ca 0.1-3 mg / L, Mg 1-300 mg / L, and oil content 10-50 mg / L.
[0092] In some embodiments, referring to Figure 2, step S100 is followed by:
[0093] S500: Pickling process, in which the first solid is pickled and separated into solid and liquid to obtain the second solution and the second solid;
[0094] S600: The smelting process involves smelting the second solid with a sulfiding agent and a reducing agent in an oxygen-containing atmosphere to obtain high-grade nickel matte.
[0095] In the above embodiments, the second solid obtained after the first solid is pickled is smelted with a sulfiding agent and a reducing agent in a pyrometallurgical process. The first solid produced in the neutralization process carries away the impurities in the system. At the same time, since the first solid is used as the raw material for the pyrometallurgical process, a portion of the nickel can remain in the first solid without repeated washing, which reduces the number of filter presses required and reduces the workload of unloading slag.
[0096] In some embodiments, acid washing of the first solid includes stirring and washing the first solid with a dilute acid solution with a pH of 1.5 to 2.0, wherein the dilute acid solution may be a dilute sulfuric acid solution.
[0097] In some embodiments, the nickel content in the second solid of step S500 is 10%-20%, for example, it can be any value between 10%, 12%, 13%, 15%, 17%, 19%, 20%, or 10%-20%.
[0098] In some embodiments, the mass ratio of the second solid, the sulfur element in the vulcanizing agent, and the reducing agent in step S600 is 1:(0.03-0.04):(0.08-0.12).
[0099] In some embodiments, the sulfiding agent is sulfur or a sulfide; the reducing agent is coke powder, bituminous coal or anthracite.
[0100] In some embodiments, at least 80 wt% of the reducing agent can pass through an 80-mesh sieve.
[0101] In some embodiments, the melting temperature is 1200℃-1600℃, for example, it can be any value between 1200℃, 1250℃, 1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃, 1600℃ or 1200℃-1600℃.
[0102] In some embodiments, the composition of high-grade nickel matte includes: Ni 60%-73%, Co 1%-2%, Cu 3%-8%, Fe 4-10%, and S 18%-23%.
[0103] In some embodiments, sodium hydroxide (meeting GB / T209-2018) is added to the anolyte during the nickel plating process, and the resulting nickel plating material includes nickel hydroxide.
[0104] In some embodiments, sodium carbonate (meeting GB / T210-2022) is added to the anolyte during the nickel plating process, and the resulting nickel plating material includes nickel carbonate.
[0105] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0106] Example 1
[0107] Example 1 provides a method for treating nickel sulfate solution, comprising the following steps:
[0108] The MHP raw material was added to the anolyte and leached with sulfuric acid to obtain a nickel sulfate stock solution with the following composition: Ni 68 g / L, Co 3.2 g / L, Mn 3.2 g / L, Cu 3.0 g / L, Cr 100 mg / L, Fe 500 mg / L, Al 300 mg / L, Si 100 mg / L, Ca 100 mg / L, and Mg 1.0 g / L.
[0109] In the neutralization process, a nickel-based neutralizing agent (nickel precipitate containing nickel hydroxide) is added to the original nickel sulfate solution to adjust the pH to 4.0. The process temperature is controlled at around 65℃. After stabilization for a period of time, solid and liquid are separated to obtain the first solid and the first solution (crude nickel sulfate solution). The composition of the first solution is: Ni 65g / L, Co 3g / L, Mn 3g / L, Cu 1.0g / L, Cr 50mg / L, Fe 50mg / L, Al 50mg / L, Si 80mg / L, Ca 100mg / L, Mg 1.0g / L.
[0110] In the pickling process, the first solid is stirred and washed with a dilute acid solution with a pH of 1.5 to 2.0 for a period of time, followed by solid-liquid separation to obtain a second solid and a second solution. The second solution is returned to the system for use. The composition of the second solid includes: Ni 10%, Co 0.5%, Cu 1%, and Fe 3.5%.
[0111] In the smelting process, the second solid is fed into a blowing furnace with sulfur and coke powder at a ratio of 1:0.04:0.12, and oxygen-enriched air is introduced. The mixture is smelted at 1200℃ to obtain high-grade nickel matte. The composition of high-grade nickel matte includes: Ni 60%, Co 1%, Cu 6%, Fe 10%, and S 23%.
[0112] The extraction and oil removal process includes:
[0113] In the first saponification step, the first extractant P204 is saponified with nickel hydroxide-containing precipitated nickel material at 45°C to obtain the first nickel soap organic phase, in which the nickel content is 6.5 g / L.
[0114] In the first extraction step, the first solution and the first nickel soap organic are extracted at a volume ratio of 1:2. The resulting raffinate is the third solution, which contains elements such as nickel, cobalt, and magnesium. Impurities such as manganese, copper, iron, and calcium are extracted into the organic phase.
[0115] In the first degreasing step, nickel hydroxide-containing precipitated material is added to the third solution, and the mixture is stirred and slurried to remove oil. The nickel hydroxide adsorbs organic matter, and after solid-liquid separation, a third solid (containing adsorbed organic matter) and a fourth solution are obtained. The organic phase content of the fourth solution is 3.6 mg / L.
[0116] In the second saponification step, the second extractant P507 and the nickel precipitate containing nickel hydroxide are saponified at 45°C to obtain the second nickel soap organic phase, which has a nickel content of 6 g / L.
[0117] In the second extraction step, the fourth solution and the second nickel soap organic phase are extracted at a volume ratio of 1:3. Elements such as cobalt and magnesium are extracted into the organic phase. The resulting extract residue is the fifth solution, which has the following composition: Ni 70 g / L, Co 24 mg / L, Mn 2 mg / L, Cu 2 mg / L, Cr 1 mg / L, Fe 1 mg / L, Al 1 mg / L, Si 50 mg / L, Ca 3 mg / L, Mg 300 mg / L, and oil 10 mg / L.
[0118] In the second degreasing step, nickel hydroxide-containing precipitated material is added to the fifth solution, and the mixture is stirred and slurried to remove oil. After solid-liquid separation, a fourth solid and a sixth solution are obtained. The organic phase content of the sixth solution is 3.5 mg / L.
[0119] In the electrowinning process, the sixth solution is pumped into the electrowinning tank, and after electrowinning, anolyte and electrowinning nickel plates are obtained.
[0120] In the nickel immersion process, liquid alkali is added to the anolyte to precipitate nickel and obtain nickel immersion material containing nickel hydroxide.
[0121] Example 2
[0122] Example 2 provides a method for treating nickel sulfate solution, comprising the following steps:
[0123] The MHP raw material was added to the anolyte and leached with sulfuric acid to obtain a nickel sulfate stock solution with the following composition: Ni 100 g / L, Co 10 g / L, Mn 10 g / L, Cu 3 g / L, Cr 200 mg / L, Fe 1000 mg / L, Al 600 mg / L, Si 600 mg / L, Ca 300 mg / L, and Mg 4 g / L.
[0124] In the neutralization process, a nickel-based neutralizing agent (nickel carbonate-containing precipitated nickel material) is added to the original nickel sulfate solution to adjust the pH to 5.0. The process temperature is controlled at around 70℃. After stabilization for a period of time, solid and liquid are separated to obtain the first solid and the first solution (crude nickel sulfate). The composition of the first solution is: Ni 95g / L, Co 9g / L, Mn 9g / L, Cu 2g / L, Cr 10mg / L, Fe 5mg / L, Al 10mg / L, Si 35mg / L, Ca 288mg / L, Mg 3.9g / L.
[0125] In the pickling process, the first solid is stirred and washed with a dilute acid solution with a pH of 1.5 to 2.0 for a period of time, followed by solid-liquid separation to obtain a second solid and a second solution. The second solution is returned to the system for use. The composition of the second solid includes: Ni 14%, Co 0.5%, Cu 2.0%, and Fe 5%.
[0126] In the smelting process, the second solid is fed into a blowing furnace with sulfur and bituminous coal at a ratio of 1:0.035:0.1, and oxygen-enriched air is introduced. The mixture is smelted at 1350℃ to obtain high-grade nickel matte. The composition of high-grade nickel matte includes: Ni 65%, Co 1%, Cu 8%, Fe 6%, and S 20%.
[0127] The extraction and oil removal process includes:
[0128] In the first saponification step, the first extractant P204 is saponified with nickel carbonate-containing nickel precipitate material at 55°C to obtain the first nickel soap organic phase, in which the nickel content is 10 g / L.
[0129] In the first extraction step, the first solution and the first nickel soap organic are extracted at a volume ratio of 1:3. The resulting raffinate is the third solution, which contains elements such as nickel, cobalt, and magnesium. Impurities such as manganese, copper, zinc, iron, and calcium are extracted into the organic phase.
[0130] In the first degreasing step, the third solution is passed through a nickel-containing nickel precipitate filter cake for degreasing. The nickel hydroxide adsorbs organic matter, and after solid-liquid separation, a third solid (containing adsorbed organic matter) and a fourth solution are obtained. The organic phase content of the fourth solution is 5.0 mg / L.
[0131] In the second saponification step, the second extractant P507 and the nickel carbonate-containing precipitated material are saponified at 45°C to obtain the second nickel soap organic phase, which has a nickel content of 10 g / L.
[0132] In the second extraction step, the fourth solution and the second nickel soap organic phase are extracted at a volume ratio of 1:4. Elements such as cobalt and magnesium are extracted into the organic phase. The resulting extract residue is the fifth solution, which has the following composition: Ni 100g / L, Co 10mg / L, Mn 1mg / L, Cu 1mg / L, Cr 0.5mg / L, Fe 0.5mg / L, Al 0.5mg / L, Si 30mg / L, Ca 2mg / L, Mg 100mg / L, and oil content 20mg / L.
[0133] In the second degreasing step, nickel carbonate-containing precipitated material is added to the fifth solution, stirred and slurried to remove oil, and after solid-liquid separation, a fourth solid and a sixth solution are obtained. The organic phase content of the sixth solution is 4.5 mg / L.
[0134] In the electrowinning process, the sixth solution is pumped into the electrowinning tank, and after electrowinning, anolyte and electrowinning nickel plates are obtained.
[0135] In the nickel immersion process, soda ash is added to the anolyte to precipitate nickel carbonate-containing immersion nickel material.
[0136] Example 3
[0137] Example 3 provides a method for treating nickel sulfate solution, comprising the following steps:
[0138] The MHP raw material was added to the anolyte and leached with sulfuric acid to obtain a nickel sulfate stock solution with the following composition: Ni 112 g / L, Co 21 g / L, Mn 21 g / L, Cu 0.1 g / L, Cr 300 mg / L, Fe 2000 mg / L, Al 1000 mg / L, Si 1000 mg / L, Ca 555 mg / L, and Mg 6.1 g / L.
[0139] In the neutralization process, a nickel-based neutralizing agent (nickel precipitate containing nickel hydroxide) is added to the original nickel sulfate solution to adjust the pH to 5.5. The process temperature is controlled at around 80℃. After stabilization for a period of time, solid and liquid are separated to obtain the first solid and the first solution (crude nickel sulfate). The composition of the first solution is: Ni 108g / L, Co 20g / L, Mn 21g / L, Cu 0.1g / L, Cr 1mg / L, Fe 0.1mg / L, Al 1mg / L, Si 20mg / L, Ca 550mg / L, Mg 6.0g / L.
[0140] In the pickling process, the first solid is stirred and washed with a dilute acid solution with a pH of 1.5 to 2.0 for a period of time, followed by solid-liquid separation to obtain a second solid and a second solution. The second solution is returned to the system for use. The composition of the second solid includes: Ni 20%, Co 1%, Cu 0.5%, and Fe 6%.
[0141] In the smelting process, the second solid is fed into the blowing furnace with sulfur and anthracite in a ratio of 1:0.03:0.08, and oxygen-enriched air is introduced. The mixture is smelted at 1600℃ to obtain high-grade nickel matte. The composition of high-grade nickel matte includes: Ni 73%, Co 2%, Cu 3%, Fe 4%, and S 18%.
[0142] The extraction and oil removal process includes:
[0143] In the first saponification step, the first extractant P204 is saponified with nickel hydroxide-containing precipitated nickel material at 65°C to obtain the first nickel soap organic phase, in which the nickel content is 12 g / L.
[0144] In the first extraction step, the first solution and the first nickel soap organic are extracted at a volume ratio of 1:3. The resulting raffinate is the third solution, which contains elements such as nickel, cobalt, and magnesium. Impurities such as manganese, copper, zinc, iron, and calcium are extracted into the organic phase.
[0145] In the first degreasing step, nickel hydroxide-containing precipitated material is added to the third solution, and the mixture is stirred and slurried to remove oil. The nickel hydroxide adsorbs organic matter, and after solid-liquid separation, a third solid (containing adsorbed organic matter) and a fourth solution are obtained. The organic phase content of the fourth solution is 4.6 mg / L.
[0146] In the second saponification step, the second extractant P507 is saponified with nickel hydroxide-containing precipitated nickel material at 65°C to obtain the second nickel soap organic phase, which has a nickel content of 11.8 g / L.
[0147] In the second extraction step, the fourth solution and the second nickel soap organic phase are extracted at a volume ratio of 1:4. Elements such as cobalt and magnesium are extracted into the organic phase. The resulting extract is the fifth solution, which has the following composition: Ni 120 g / L, Co 5 mg / L, Mn 0.01 mg / L, Cu 0.01 mg / L, Cr 0.1 mg / L, Fe 0.01 mg / L, Al 0.1 mg / L, Si 20 mg / L, Ca 0.4 mg / L, Mg 1.0 mg / L, and oil content 50 mg / L.
[0148] In the second degreasing step, nickel hydroxide-containing precipitated material is added to the fifth solution, and the mixture is stirred and slurried to remove oil. After solid-liquid separation, a fourth solid and a sixth solution are obtained. The organic phase content of the sixth solution is 3.0 mg / L.
[0149] In the electrowinning process, the sixth solution is pumped into the electrowinning tank, and after electrowinning, anolyte and electrowinning nickel plates are obtained.
[0150] In the nickel immersion process, liquid alkali is added to the anolyte to precipitate nickel and obtain nickel immersion material containing nickel hydroxide.
[0151] Comparative Example 1
[0152] Comparative Example 1 provides a method for treating a nickel sulfate solution, which differs from Example 1 in that calcium carbonate is used to adjust the pH value in the neutralization process. The first solid obtained in Comparative Example 1 has a high calcium content and cannot be directly used to produce high-grade nickel matte. Furthermore, the Ca content of the first solution is >550 mg / L, indicating saturated calcium. This leads to the precipitation of saturated calcium and blockage of pipelines during subsequent operations such as liquid transfer.
[0153] Comparative Example 2
[0154] The difference between Comparative Example 2 and Example 1 lies in the following: The first solid was treated using a wet process, while in Comparative Example 2, the first solid was subjected to a second leaching with water and sulfuric acid at a higher temperature. After leaching, an alkaline material was added to the slurry to adjust the pH to 4.0-5.0. After stabilization for a period, solid-liquid separation was performed. The resulting filter residue was washed twice and then outsourced for further processing. The filtrate was generally returned to the feeding end for pulping. The difference from Example 1 is that the first solid underwent a second leaching with acid, pH adjustment for impurity removal, and solid-liquid separation to recover metallic nickel and open-circuit impurities. This process is complex and involves the internal circulation of impurities such as Al. Furthermore, the impurity removal residue is hazardous waste, resulting in high treatment costs.
[0155] Comparative Example 3
[0156] The difference between Comparative Example 3 and Example 1 is that the third or fifth solution is flowed through an activated carbon column at a certain flow rate. The activated carbon is replaced as needed based on the oil content of the degreased solution. The replaced activated carbon is then washed with water and regenerated or treated externally. The difference from Example 1 is that while activated carbon degreasing provides a stable oil removal effect, it requires a large amount of activated carbon (4-8 kg per cubic meter of solution), resulting in a high loss of extractant (1-2 L per cubic meter of solution). Furthermore, the used activated carbon is classified as hazardous solid waste, leading to high disposal costs.
[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
[0158] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
Claims
1. A method for treating nickel sulfate solution, comprising: In the neutralization process, a nickel-based neutralizing agent is added to the nickel sulfate solution to remove impurities, resulting in a first solution and a first solid. In the extraction and degreasing process, the first solution is subjected to nickel soap extraction and degreasing to obtain a degreased solution; In the electrowinning process, the degreasing solution is electrowinning to obtain an anolyte and an electrowinning nickel plate; In the nickel plating process, sodium hydroxide and / or sodium carbonate are added to the anolyte, and after precipitation, nickel plating material is obtained; the nickel plating material is used in the nickel-based neutralizing agent.
2. The method for treating nickel sulfate solution according to claim 1 further includes: In the pickling process, the first solid is pickled and separated into solid and liquid components to obtain a second solution and a second solid. In the smelting process, the second solid is smelted with a sulfiding agent and a reducing agent in an oxygen-containing atmosphere to obtain high-grade nickel matte.
3. The method for treating nickel sulfate solution according to claim 2, wherein, At least one of the following conditions must be met: A. The nickel content in the second solid is 10%-20%; B. The mass ratio of the second solid to the sulfur element in the vulcanizing agent and the reducing agent is 1:(0.03-0.04):(0.08-0.12); C. The vulcanizing agent is sulfur or a sulfide; D. The reducing agent is coke powder, bituminous coal, or anthracite; E. At least 80 wt% of the reducing agent can pass through an 80-mesh sieve; F. The melting temperature is 1200℃-1600℃; G. The composition of the high-grade nickel matte includes: Ni 60%-73%, Co 1%-2%, Cu 3%-8%, Fe 4-10%, and S 18%-23%; H. The composition of nickel sulfate solution includes Ni 60-120 g / L, Co 3-21 g / L, Mn 3-21 g / L, Cu 0.1-3 g / L, Cr 100-300 mg / L, Fe 500-2000 mg / L, Al 300-1000 mg / L, Si 100-1000 mg / L, Ca 100-600 mg / L, and Mg 1-6.5 g / L.
4. The method for treating nickel sulfate solution according to claim 1, wherein, The extraction and oil removal process includes: In the first saponification step, the first extractant is saponified with the nickel immersion material to obtain the first nickel soap organic phase; In the first extraction step, the first solution is contacted with the first nickel soap organic phase for extraction to obtain a third solution; In the first degreasing step, the third solution is brought into contact with the nickel plating material to remove oil, resulting in a fourth solution and a third solid.
5. The method for treating nickel sulfate solution according to claim 4, wherein, Also includes: The second saponification step involves saponifying the second extractant with the nickel precipitate to obtain a second nickel soap organic phase. In the second extraction step, the fourth solution is contacted with the second nickel soap organic phase for extraction to obtain the fifth solution; In the second degreasing step, the fifth solution is brought into contact with the nickel plating material to remove oil, resulting in a sixth solution and a fourth solid, wherein the sixth solution is the degreasing solution.
6. The method for treating nickel sulfate solution according to claim 5, wherein, The nickel precipitate material saponified with the first extractant includes the third solid; the nickel precipitate material saponified with the second extractant includes the fourth solid.
7. The method for treating nickel sulfate solution according to claim 6, wherein, At least one of the following conditions must be met: The saponification temperature described in A is 45-65℃; B. The first extractant is selected from P204; C. The second extractant is selected from P507; D. The nickel content in the second nickel soap organic phase and the first nickel soap organic phase are independently 6-12 g / L.
8. The method for treating nickel sulfate solution according to claim 5, wherein, At least one of the following conditions must be met: A. The oil content of the fourth and sixth solutions is ≤5 mg / L; B. The fifth solution comprises: Ni 70-120 g / L, Co 5-24 mg / L, Mn 0.01-2 mg / L, Cu 0.01-2 mg / L, Cr ≤1 mg / L, Fe 0.01-1 mg / L, Al 0.1-1 mg / L, Si 20-50 mg / L, Ca 0.1-3 mg / L, Mg 1-300 mg / L, and oil 10-50 mg / L.
9. The method for treating nickel sulfate solution according to claim 1, wherein, At least one of the following conditions must be met: A. The pH value of the impurity removal process is 4.0-6.0; B. The temperature of the impurity removal process is 65-80℃; C. Dry weight (t) of the nickel-based neutralizing agent: Volume (m³) of the nickel sulfate solution 3 ) = 1:60~300; D. The components of the first solution include: Ni 65-110 g / L, Co 3-20 g / L, Mn 3-20 g / L, Cu 0.1-2 g / L, Cr 1-50 mg / L, Fe 0.1-50 mg / L, Al 1-50 mg / L, Si 20-80 mg / L, Ca 100-550 mg / L, and Mg 1-6 g / L; E. The first solid comprises: nickel hydroxide, iron-silicon-aluminum precipitate, and manganese dioxide.
10. The method for treating nickel sulfate solution according to claim 1, wherein, The method for preparing the nickel sulfate solution includes: adding acid and the anolyte to nickel cobalt hydroxide and then leaching the solution.