A method for treating a laterite nickel ore liquid with high calcium and magnesium content and its application

Abstract

The invention discloses a treatment method and application of a laterite nickel ore liquid with high calcium and magnesium contents, comprising the following steps: S1. configuring 2-hexylundecanoic acid and an HBL110 / HBL116 extractant to form an extracted organic phase; S2. co-extracting the extracted organic phase with the laterite nickel ore liquid with high calcium and magnesium contents into nickel and cobalt to obtain a first loaded organic phase and a raffinate; and S3. washing the first loaded organic phase with a washing liquid to obtain a second loaded organic phase and washing water, and refluxing the washing water into the laterite nickel ore liquid with high calcium and magnesium contents; S4. adding a stripping liquid into the second loaded organic phase for stripping to obtain a nickel-cobalt salt solution and an organic phase after stripping; and S5. saponifying the organic phase after stripping to obtain a regenerated extracted organic phase. This solution is applicable to a high calcium and magnesium environment, can prevent calcium and magnesium from forming a third phase, and has a good effect of separating and purifying nickel and cobalt.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrometallurgy, and in particular to a method for treating a laterite nickel ore liquid with high calcium and magnesium contents and an application thereof. Background Art

[0002] Under the dual pressures of energy and environmental protection, the new energy vehicle industry is developing rapidly, and its industrialization is accelerating. However, with the continuous depletion of nickel sulfide ore, the current and future supply of battery-grade raw materials will fall far short of meeting the strong market demand for new energy vehicles. How to directly process laterite nickel ore through hydrometallurgical technology to deeply separate and recover impurities, thereby obtaining battery-grade nickel and cobalt raw materials while reducing the production costs of automotive batteries, has become a challenge facing new energy companies in their long-term development.

[0003] During the high-pressure acid leaching process of laterite nickel ore, a large amount of magnesium and calcium are also leached into the laterite nickel ore leachate, forming a laterite nickel ore liquid with high calcium and magnesium content, which is not conducive to the recovery of nickel and cobalt. In the related art, the wet process for extracting battery-grade nickel and cobalt from laterite nickel ore liquid with high calcium and magnesium content mainly includes precipitation and extraction. Because the pH of calcium and magnesium hydrolysis is higher than that of nickel and cobalt, when purifying nickel and cobalt by precipitation, fluorides such as sodium fluoride or ammonium fluoride are generally added to form insoluble precipitates with magnesium and calcium to remove calcium and magnesium; however, this process not only consumes a large amount of expensive fluorides and has high economic costs, but also easily introduces fluoride ions and nickel and cobalt fluorides, resulting in a large loss of nickel and cobalt. In addition, the obtained nickel and cobalt product is also accompanied by the entrainment of calcium, magnesium and fluoride ions. In the industrial extraction process, calcium is first removed from laterite nickel ore with high calcium and magnesium content using P204. This is followed by cobalt extraction with P507, magnesium removal with P507, and deep impurity removal with C272. Finally, nickel and cobalt are concentrated to the target concentration of battery-grade nickel-cobalt raw material using a dedicated nickel-cobalt enrichment line. This process is cumbersome and costly, and the dispersion loss rate of nickel and cobalt is high. Furthermore, calcium and a small amount of magnesium can hydrolyze to form a third phase, which is continuously enriched in the organic phase of the extraction, preventing the extraction tank from operating normally and severely affecting the nickel-cobalt extraction rate and the purity of the final product. However, separating calcium and magnesium from a solution with low calcium and magnesium content does not encounter these issues.

[0004] Therefore, the design idea of ​​the treatment method of laterite nickel ore liquid with high calcium and magnesium content is different from that of the treatment method of laterite nickel ore liquid with low calcium and magnesium content. It is necessary to design a treatment method of laterite nickel ore liquid with high calcium and magnesium content that has a short process, low cost, and good nickel and cobalt purification effect. Summary of the Invention

[0005] In view of this, the present application provides a method for treating a laterite nickel ore liquid with high calcium and magnesium content and its application, which has a good nickel and cobalt purification effect.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a method for treating a laterite nickel ore solution having a high calcium and magnesium content, comprising the following steps:

[0008] S1. The 2-hexyl undecanoic acid and the first extractant are configured as a synergistic extractant, the synergistic extractant is diluted with a diluent and then saponified with liquid alkali to obtain an extracted organic phase, wherein the first extractant is an extractant HBL110 or an extractant HBL116;

[0009] S2. The extracted organic phase is mixed with a laterite nickel ore liquid having a high calcium and magnesium content, and nickel and cobalt are co-extracted to obtain a first loaded organic phase and a raffinate; in the laterite nickel ore liquid having a high calcium and magnesium content, the calcium ion content is 0.5 to 1 g / L, the magnesium ion content is 4-7 g / L, the nickel ion content is 2.5 to 4 g / L, and the cobalt ion content is 0.2 to 0.5 g / L;

[0010] S3. Washing the first loaded organic phase with a washing liquid to obtain a second loaded organic phase and a wash water, and the wash water is refluxed to the laterite nickel ore liquid having a high calcium and magnesium content;

[0011] S4. A stripping solution is added to the second loaded organic phase for stripping to obtain a nickel-cobalt salt solution and an organic phase after stripping, wherein the nickel-cobalt salt solution is crystallized to obtain a nickel-cobalt salt;

[0012] S5. saponifying the organic phase after stripping to obtain a regenerated extraction organic phase.

[0013] Preferably, the volume ratio of 2-hexylundecanoic acid to the first extractant is 1:3-15.

[0014] Preferably, in step S1, the diluent includes one or more of kerosene, No. 260 solvent oil or Escaid 110 solvent oil, and the saponifying agent includes one or more of sodium hydroxide, nickel hydroxide and ammonia water.

[0015] Preferably, in step S1, the dilution rate of the synergistic extractant is 10-50%, the saponification rate is 20-70%, and the saponification level is 1-2.

[0016] Preferably, in step S2, the volume ratio of the extracted organic phase to the laterite nickel ore liquid with high calcium and magnesium content is 1:0.5-7, and the extraction stages of nickel-cobalt co-extraction are 1-13.

[0017] Preferably, in step S3, the concentration of the washing liquid is 0.05-0.5 mol / L, the volume ratio of the first loaded organic phase to the washing liquid is 1:0.1-0.5, and the washing stage is 1-10; the washing liquid includes one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, phosphoric acid solution, acetic acid solution, and citric acid solution.

[0018] Preferably, in step S4, the concentration of the stripping solution is 0.5-2.5 mol / L, the volume ratio of the second loaded organic phase to the stripping solution is 1:0.05-1, and the stripping stage is 2-8; the stripping solution includes one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, phosphoric acid solution, acetic acid solution, and citric acid solution.

[0019] Preferably, in step S5, the saponification stage is 1-2.

[0020] In a second aspect, the present application provides a nickel-cobalt salt crystal.

[0021] In a third aspect, the present application provides an application of nickel-cobalt salt crystals in batteries.

[0022] The beneficial effects of this application are as follows:

[0023] 1. The method for treating a laterite nickel ore solution with high calcium and magnesium content in the present application has a short process, low cost, and good extraction effect;

[0024] 2. This application can produce battery-grade nickel-cobalt sulfate products from high-calcium-magnesium laterite nickel ore liquid through a one-step co-extraction process;

[0025] 3. This application solves the problems in the prior art of purifying nickel and cobalt from laterite nickel ore liquid with high calcium and magnesium contents, such as the long process flow and the easy hydrolysis of calcium and magnesium during extraction to form a third phase. It reduces the large consumption of various chemical reagents during nickel and cobalt purification, improves the purity of the nickel and cobalt products, and greatly reduces the overall cost of nickel and cobalt recovery.

[0026] 4. The synergistic extractant system used in this application has low water solubility and a large separation coefficient for nickel, cobalt, and calcium and magnesium. It can completely extract nickel and cobalt from laterite nickel ore liquid with high calcium and magnesium content, reducing the pressure during wastewater treatment. At the same time, the purity of the obtained nickel and cobalt products is extremely high, providing high-quality, cost-effective raw material guarantee for the positive electrode material of ternary batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the process flow chart of this scheme. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0030] Figure 1 As shown, the present application provides a method for treating a laterite nickel ore liquid with high calcium and magnesium content, comprising the following steps:

[0031] S1. 2-Hexylundecanoic acid (C 16 H 32 O2) and the first extractant are configured into a synergistic extractant, a diluent is added to the synergistic extractant and then saponified with liquid alkali to obtain an extracted organic phase, wherein the first extractant is HBL110 extractant or HBL116 extractant;

[0032] S2. The extracted organic phase was mixed with a laterite nickel ore solution having a high calcium and magnesium content, and nickel and cobalt were co-extracted to obtain a first loaded organic phase and a raffinate; in the laterite nickel ore solution having a high calcium and magnesium content, the calcium ion content was 0.7 g / L and the magnesium ion content was 6 g / L; the nickel ion content was 2.5 to 4 g / L and the cobalt ion content was 0.2 to 0.5 g / L;

[0033] S3. Washing the first loaded organic phase with a washing solution to obtain a second loaded organic phase and a wash water, and returning the wash water to the laterite nickel ore solution having a high calcium and magnesium content; the washing solution comprises one or more of a sulfuric acid solution, a hydrochloric acid solution, a nitric acid solution, a phosphoric acid solution, an acetic acid solution, and a citric acid solution;

[0034] S4. A stripping solution is added to the second loaded organic phase for stripping to obtain a nickel-cobalt salt solution and an organic phase after stripping, wherein the nickel-cobalt salt solution is crystallized to obtain a nickel-cobalt salt;

[0035] S5. saponifying the organic phase after stripping to obtain a regenerated extraction organic phase.

[0036] The synergistic extractant in this application is an extraction system consisting of 2-hexyl undecanoic acid and HBL110 extractant, or an extraction system consisting of 2-hexyl undecanoic acid and HBL116 extractant. In this application, the properties, usage mechanism and effect of HBL110 extractant are the same as those of HBL116 extractant. 16 H 32 O2), HBL110 extractant, and HBL116 extractant are all commercially available chemical reagents.

[0037] The method of the present application is applicable to various nickel-cobalt-containing materials such as laterite nickel ore, nickel sulfide ore, and wastewater, as well as various acidic or neutral liquids such as sulfuric acid, hydrochloric acid, nitric acid, and oxalic acid with high calcium, high magnesium, or high calcium-magnesium content. Ultimately, various products such as sulfates, chlorides, carbonates, acetates, and oxalates of nickel or cobalt and mixed nickel and cobalt can be obtained.

[0038] The process flow and principle of this scheme are as follows:

[0039] In this solution, step S1 is configured with an extraction organic phase, and 2-hexyl undecanoic acid and a first extractant are combined to form a synergistic extraction system. The extraction system has low water solubility and a large separation coefficient for nickel, cobalt, and calcium and magnesium. The nickel and cobalt in the laterite nickel ore liquid with high calcium and magnesium content can be completely extracted. In addition, under this extraction system, calcium and magnesium will not hydrolyze to form a third phase. It is worth noting that in addition to its low water solubility, the extraction system also includes the following synergistic mechanism: 2-hexyl undecanoic acid (C 16 H 32O2) has a large separation coefficient for nickel, cobalt and calcium and magnesium. However, as a typical carboxylic acid extractant, the pH of the raffinate after co-extraction of nickel and cobalt increases significantly relative to the pH of the feed solution, which causes a large amount of calcium and part of the magnesium to hydrolyze and produce precipitation that is continuously enriched in the organic phase, making it impossible for the extraction tank to operate normally. The extraction rate of cobalt by HBL110 is relatively low relative to nickel. The cobalt in the washing section is easily eluted into the washing liquid, and the concentration of cobalt in the laterite nickel ore feed solution itself is very low, so the recovery rate of cobalt is low. However, after HBL110 extraction, the pH of the raffinate does not increase relative to the feed solution. In this case, there is no hydrolysis of high-content calcium and magnesium. Therefore, for the synergistic extractant composed of these two extractants, on the basis of adjusting and optimizing the content of the two, the purpose of simultaneously recovering nickel and cobalt from a feed solution with high calcium and high magnesium content can be achieved, while solving the problem of calcium and magnesium hydrolysis. Step S2 is nickel-cobalt co-extraction, using the extracted organic phase obtained in step S1 to carry out nickel-cobalt co-extraction with the laterite nickel ore liquid with high calcium and magnesium content, and the obtained first loaded organic phase carries all the nickel and cobalt and a small amount of calcium and magnesium in the laterite nickel ore liquid with high calcium and magnesium content, and most of the impurities such as calcium and magnesium enter the raffinate for removal; in order to further improve the purity of nickel and cobalt, in step S3, the first loaded organic phase loaded with all the nickel and cobalt and a small amount of calcium and magnesium is washed, and after washing with the washing liquid, the calcium and magnesium in the first loaded organic phase are transferred, and the first loaded organic phase is converted into a second loaded organic phase containing only nickel and cobalt, and the washing water contains There are a small amount of nickel and cobalt and calcium and magnesium in the first loaded organic phase. In order to further improve the recovery rate of nickel and cobalt, step S3 also merges the wash water into the laterite nickel ore liquid with high calcium and magnesium content in step S2 for reflux, and performs nickel and cobalt co-extraction again as the extraction object; step S4 is a reverse co-extraction process, the purpose of which is to transfer the nickel and cobalt in the second loaded organic phase to the aqueous phase to obtain a nickel cobalt salt solution, and the organic phase after reverse co-extraction obtained after reverse co-extraction still contains the synergistic extractant component of this scheme. In order to save raw materials and improve the co-extraction effect, step S5 regenerates the synergistic extractant in the organic phase after reverse extraction, and obtains a regenerated extracted organic phase after regeneration.

[0040] The volume ratio of 2-hexylundecanoic acid to the first extractant is 1:5-15. At this ratio, the synergistic extractant is most effective in separating nickel and cobalt from laterite nickel ore with high calcium and magnesium content. Conversely, if the ratio of 2-hexylundecanoic acid is too high, calcium and magnesium will hydrolyze; and if the first extractant content is too high, the cobalt recovery rate is too low. Preferably, the volume ratio of 2-hexylundecanoic acid to the first extractant is 1:8.

[0041] In step S1, the diluent includes one or more of sulfonated kerosene, No. 260 solvent oil or Escaid 110 solvent oil; preferably, the diluent is sulfonated kerosene, and the saponifying agent includes one or more of sodium hydroxide, nickel hydroxide and ammonia water.

[0042] In step S1, the saponifying agent is liquid alkali, including but not limited to one or more of sodium hydroxide, potassium hydroxide, and ammonia water. In some embodiments, the concentration of the liquid alkali is 10-30%.

[0043] In step S1, the dilution rate of the co-extractant is 10-50%, the saponification rate is 20-70%, and the saponification stage is 1-2. Suitable, but not limiting, dilution rates of the co-extractant are 10%, 20%, 30%, 40%, or 50%, and suitable, but not limiting, saponification rates are 20%, 30%, 40%, 50%, 60%, or 70%.

[0044] In step S2, the volume ratio of the extracted organic phase to the laterite nickel ore solution with high calcium and magnesium content is 1:0.2-3, and the extraction stage of nickel-cobalt co-extraction is 1-13; suitably but not limitatively, the volume ratio of the extracted organic phase to the laterite nickel ore solution with high calcium and magnesium content is 1:0.2, 1:0.5, 1:1, 1:2, 1:3; suitably but not limitatively, the extraction stage of nickel-cobalt co-extraction is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13.

[0045] In step S3, the concentration of the washing liquid is 0.05-0.5 mol / L, the volume ratio of the first loaded organic phase to the washing liquid is 1:0.1-0.5, and the washing stage is 1-10; suitably but not limitatively, the concentration of the washing liquid is 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L; suitably but not limitatively, the volume ratio of the first loaded organic phase to the washing liquid is 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5; suitably but not limitatively, the washing stage is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12; the washing liquid comprises one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, phosphoric acid solution, acetic acid solution, and citric acid solution.

[0046] In step S4, the concentration of the stripping solution is 0.5-1.5 mol / L, the volume ratio of the second loaded organic phase to the stripping solution is 1:0.05-1, and the stripping stage is 2-8; suitably but not limitatively, the concentration of the stripping solution is 0.5 mol / L, 0.8 mol / L, 1.0 mol / L, 1.5 mol / L, 2 mol / L and 2.5 mol / L; suitably but not limitatively, the volume ratio of the second loaded organic phase to the stripping solution is 1:0.1, 1:0.2, 1:0.5, 1:0.8, 1:1; suitably but not limitatively, the stripping stage is 2, 3, 4, 5, 6, 7, and 8; the stripping solution comprises one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, phosphoric acid solution, acetic acid solution, and citric acid solution.

[0047] In step S5, the saponification stage is 1-2.

[0048] The present application provides a nickel-cobalt salt. The nickel-cobalt salt of the present application is derived from a laterite nickel ore solution with a high calcium and magnesium content. In some embodiments, the nickel ion and cobalt ion contents in the laterite nickel ore solution with a high calcium and magnesium content are 3.6 g / L and 0.35 g / L, respectively.

[0049] The present application provides an application of a nickel-cobalt salt in a battery. The nickel-cobalt salt of the present application has low impurity content and high purity, and has good cyclability and safety when used as a positive electrode material for a ternary battery.

[0050] The present invention is further described below through specific examples.

[0051] Example 1

[0052] A method for treating a laterite nickel ore solution with high calcium and magnesium contents comprises the following steps:

[0053] S1. Configuration of the extracted organic phase: 2-hexyl undecanoic acid and HBL110 extractant were configured as a synergistic extractant, sulfonated kerosene was added to the synergistic extractant and then saponified with sodium hydroxide, the dilution rate of the synergistic extractant was controlled to be 50%, the saponification rate was 70%, and the saponification level was 1, to obtain an extracted organic phase; wherein the volume ratio of 2-hexyl undecanoic acid and HBL110 extractant was 1:8;

[0054] S2. Nickel-cobalt co-extraction: The extracted organic phase is mixed with a laterite nickel ore solution having a high calcium and magnesium content, and nickel-cobalt co-extraction is performed. The volume ratio of the extracted organic phase to the laterite nickel ore solution having a high calcium and magnesium content is controlled to be 1:3, and the number of extraction stages for nickel-cobalt co-extraction is 5, to obtain a first loaded organic phase and a raffinate. The laterite nickel ore solution having a high calcium and magnesium content has a calcium ion content of 0.7 g / L and a magnesium ion content of 6 g / L.

[0055] S3 washing calcium and magnesium: washing the first loaded organic phase with a washing solution, controlling the concentration of the washing solution to 0.15mol / L, the volume ratio of the first loaded organic phase to the washing solution was 1: 0.25, the washing stage was 4, to obtain a second loaded organic phase and wash water, the wash water was refluxed to a high calcium and magnesium content of laterite nickel ore feed solution;

[0056] S4. Back-coextraction: adding a stripping solution to the second loaded organic phase for stripping, controlling the stripping solution concentration to 2.5 mol / L, the volume ratio of the second loaded organic phase to the stripping solution was 1: 0.1, the stripping stage was 6, and a nickel-cobalt salt solution and an organic phase after stripping were obtained, the nickel-cobalt salt solution was crystallized to obtain a nickel-cobalt salt;

[0057] S5. Regeneration of the extracted organic phase: The organic phase after stripping is subjected to saponification treatment with a saponification level of 1 to obtain a regenerated extracted organic phase.

[0058] Example 2

[0059] A method for treating a laterite nickel ore solution with high calcium and magnesium contents comprises the following steps:

[0060] S1. Configuration of the extracted organic phase: 2-hexyl undecanoic acid and HBL110 extractant were configured as a synergistic extractant, sulfonated kerosene was added to the synergistic extractant and then saponified with liquid alkali, the dilution rate of the synergistic extractant was controlled to be 40%, the saponification rate was 60%, and the saponification level was 1 to obtain an extracted organic phase; wherein the volume ratio of 2-hexyl undecanoic acid and HBL110 extractant was 1:8;

[0061] S2. Nickel-cobalt co-extraction: The extracted organic phase is mixed with a laterite nickel ore solution having a high calcium and magnesium content, and nickel-cobalt co-extraction is performed. The volume ratio of the extracted organic phase to the laterite nickel ore solution having a high calcium and magnesium content is controlled to be 1:2, and the number of extraction stages for nickel-cobalt co-extraction is 5, to obtain a first loaded organic phase and a raffinate. The laterite nickel ore solution having a high calcium and magnesium content has a calcium ion content of 0.7 g / L and a magnesium ion content of 6 g / L.

[0062] S3 washing calcium and magnesium: washing the first loaded organic phase with a washing solution, controlling the concentration of the washing solution to 0.15mol / L, the volume ratio of the first loaded organic phase to the washing solution was 1: 0.2, the washing stage was 4, to obtain a second loaded organic phase and wash water, the wash water was refluxed to a high calcium and magnesium content of laterite nickel ore feed solution;

[0063] S4. Back-coextraction: adding a stripping solution to the second loaded organic phase for stripping, controlling the stripping solution concentration to 2.5 mol / L, the volume ratio of the second loaded organic phase to the stripping solution was 1: 0.1, the stripping stage was 6, and a nickel-cobalt salt solution and an organic phase after stripping were obtained, the nickel-cobalt salt solution was crystallized to obtain a nickel-cobalt salt;

[0064] S5. Regeneration of the extracted organic phase: The organic phase after stripping is subjected to saponification treatment with a saponification level of 1 to obtain a regenerated extracted organic phase.

[0065] Example 3

[0066] A method for treating a laterite nickel ore solution with high calcium and magnesium contents comprises the following steps:

[0067] S1. Configuration of the extracted organic phase: 2-hexyl undecanoic acid and HBL110 extractant were configured as a synergistic extractant, sulfonated kerosene was added to the synergistic extractant and then saponified with liquid alkali, the dilution rate of the synergistic extractant was controlled to be 25%, the saponification rate was 60%, and the saponification level was 1 to obtain an extracted organic phase; wherein the volume ratio of 2-hexyl undecanoic acid and HBL110 extractant was 1:8;

[0068] S2. Nickel-cobalt co-extraction: The extracted organic phase is mixed with a laterite nickel ore solution having a high calcium and magnesium content, and nickel-cobalt co-extraction is performed. The volume ratio of the extracted organic phase to the laterite nickel ore solution having a high calcium and magnesium content is controlled to be 1:1.25, and the number of extraction stages for nickel-cobalt co-extraction is 4, to obtain a first loaded organic phase and a raffinate. The laterite nickel ore solution having a high calcium and magnesium content has a calcium ion content of 0.7 g / L and a magnesium ion content of 6 g / L.

[0069] S3 washing calcium and magnesium: washing the first loaded organic phase with a washing solution, controlling the concentration of the washing solution to 0.1mol / L, the volume ratio of the first loaded organic phase to the washing solution was 1: 0.2, the washing stage was 4, to obtain a second loaded organic phase and wash water, the wash water was refluxed to a high calcium and magnesium content of laterite nickel ore feed solution;

[0070] S4. Back coextraction: adding a stripping solution to the second loaded organic phase for stripping, controlling the stripping solution concentration to 2.5 mol / L, the volume ratio of the second loaded organic phase to the stripping solution was 1: 0.1, the stripping stage was 5, and a nickel-cobalt salt solution and an organic phase after stripping were obtained, the nickel-cobalt salt solution was crystallized to obtain a nickel-cobalt salt;

[0071] S5. Regeneration of the extracted organic phase: The organic phase after stripping is subjected to saponification treatment with a saponification level of 1 to obtain a regenerated extracted organic phase.

[0072] Comparative Example 1

[0073] A method for treating a laterite nickel ore solution with high calcium and magnesium contents is the same as that of Example 1 except that the HBL110 extractant in the synergistic extractant is removed.

[0074] Comparative Example 2

[0075] A method for treating a laterite nickel ore solution with high calcium and magnesium contents is the same as that in Example 1, except that 2-hexylundecanoic acid is removed from the synergistic extractant.

[0076] Comparative Example 3

[0077] A method for treating a laterite nickel ore solution with high calcium and magnesium contents is the same as Example 1 except that the volume ratio of 2-hexylundecanoic acid and HBL110 extractant in the synergistic extractant is 1:1.

[0078] Comparative Example 4

[0079] A method for treating a laterite nickel ore solution with high calcium and magnesium contents is the same as Example 1 except that the volume ratio of 2-hexylundecanoic acid to HBL110 extractant in the synergistic extractant is 1:20.

[0080] Comparative Example 5

[0081] A method for treating a laterite nickel ore solution with high calcium and magnesium content is the same as that in Example 1 except that step S3 does not include refluxing the wash water.

[0082] Evaluation Test

[0083] The raffinate and nickel-cobalt salt solution obtained in Examples 1-3 and Comparative Examples 1-5 were collected, and the main components and their contents in the raw laterite nickel ore solution with high calcium and magnesium content (hereinafter referred to as raw material) were tested. The test results are shown in Table 1.

[0084] Table 1 Test results of components in each group

[0085]

[0086]

[0087] Table 1 shows the nickel-cobalt salt solution synergistic extractants. The nickel-cobalt salt solutions in Examples 1-3 of this solution have high nickel and cobalt purity, low calcium and magnesium impurity content, and no nickel or cobalt in the raffinate. This demonstrates that the synergistic extractants of this solution are highly effective in co-extracting nickel and cobalt in a high-calcium and magnesium-content feed-liquid system, with nickel and cobalt recovery rates approaching 100%. Comparative Examples 1 and 2 utilize single extraction methods. In Comparative Example 1, calcium and magnesium hydrolyze to form a precipitate that continuously accumulates in the organic phase, affecting the phase separation in the extraction tank clarifier. This significantly reduces nickel and cobalt extraction efficiency and increases impurity content in the product. Furthermore, the pipeline occasionally clogs, requiring regular cleaning of the precipitate. The cobalt extraction rate in Comparative Example 2 is very low. In Comparative Examples 1 and 2, the volume of the high calcium and magnesium content laterite nickel ore feed liquid is the same as in Example 1, and the volumes of the obtained raffinate and nickel-cobalt salt solution are also the same. As can be seen from Table 1, the nickel-cobalt extraction rates of Comparative Examples 1 and 2 are significantly lower than those of Example 1, and the nickel-cobalt salt solution in Comparative Example 1 contains more calcium and magnesium impurities, and the effect of single extraction is far inferior to that of Example 1 of this scheme. Compared with Example 1, in Comparative Example 3, due to the excessive proportion of 2-hexyl undecanoic acid, calcium and magnesium will still be hydrolyzed to form a precipitate and enriched in the organic phase. In Comparative Example 4, the cobalt in the laterite nickel ore cannot be completely recovered. In Comparative Example 5, the recovery rate of nickel and cobalt is significantly reduced. Synergistic Extraction Agent Description In the synergistic extraction agent of this scheme, 2-hexyl undecanoic acid cannot be replaced by any acid, and the first extractant cannot be replaced and refluxed by any other nickel-cobalt extractant. Replacing 2-hexylundecanoic acid in the synergistic extractant of this solution with Versatic 10, which has extraction selectivity closest to 2-hexylundecanoic acid, revealed that the high water solubility of Versatic 10 resulted in a decreasing proportion of Versatic 10 in the organic phase, leading to a continuous decline in nickel and cobalt extraction rates during the extraction stage. The extractants HBL110 and HBL116 in this patent, as components of the synergistic extraction system, lower the pH of the feed solution after nickel and cobalt extraction, resolving the issue of calcium and magnesium hydrolysis during extraction and ensuring proper operation of the extraction tank.

[0088] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for treating a laterite nickel ore liquid with high calcium and magnesium content, characterized in that: The following steps are involved: S1. The 2-hexyl undecanoic acid and the first extractant are configured as a synergistic extractant, the synergistic extractant is diluted with a diluent and then saponified with liquid alkali to obtain an extracted organic phase, wherein the first extractant is an extractant HBL110 or an extractant HBL116; S2. The extracted organic phase is mixed with a laterite nickel ore solution having a high calcium and magnesium content, and nickel and cobalt are co-extracted to obtain a first loaded organic phase and a raffinate; the laterite nickel ore solution having a high calcium and magnesium content has a calcium ion content of 0.5 to 1 g / L, a magnesium ion content of 4 to 7 g / L, a nickel ion content of 2.5 to 4 g / L, and a cobalt ion content of 0.2 to 0.5 g / L; S3. Washing the first loaded organic phase with a washing solution to obtain a second loaded organic phase and a wash water, and returning the wash water to the high calcium and magnesium content laterite nickel ore feed solution; S4. adding a stripping solution to the second loaded organic phase for stripping to obtain a nickel-cobalt salt solution product and an organic phase after stripping, wherein the nickel-cobalt salt solution is crystallized to obtain a nickel-cobalt salt; S5. saponifying the organic phase after stripping to obtain a regenerated extraction organic phase.

2. The method for treating a laterite nickel ore liquid with high calcium and magnesium contents according to claim 1, wherein: The volume ratio of the 2-hexylundecanoic acid to the first extractant is 1:3-15.

3. The method for treating a laterite nickel ore solution having high calcium and magnesium contents according to claim 1, wherein: In step S1, the diluent includes one or more of sulfonated kerosene, No. 260 solvent oil or Escaid 110 solvent oil, and the liquid alkali includes one or more of sodium hydroxide, nickel hydroxide and ammonia water.

4. The method for treating a laterite nickel ore liquid with high calcium and magnesium contents according to claim 1, wherein: In step S1, the dilution rate of the synergistic extractant is 10-50%, the saponification rate is 20-70%, and the saponification level is 1-2.

5. The method for treating a laterite nickel ore liquid with high calcium and magnesium contents according to claim 1, wherein: In step S2, the volume ratio of the extracted organic phase to the laterite nickel ore liquid with high calcium and magnesium content is 1:0.5-7, and the extraction stage of nickel-cobalt co-extraction is 1-13.

6. The method for treating a laterite nickel ore solution having high calcium and magnesium contents according to claim 1, wherein: In step S3, the concentration of the washing liquid is 0.05-0.5 mol / L, the volume ratio of the first loaded organic phase to the washing liquid is 1:0.1-0.5, and the washing stage is 1-10; the washing liquid includes one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, phosphoric acid solution, acetic acid solution, and citric acid solution.

7. The method for treating a laterite nickel ore solution having high calcium and magnesium contents according to claim 1, wherein: In step S4, the concentration of the stripping solution is 0.5-2.5 mol / L, the volume ratio of the second loaded organic phase to the stripping solution is 1:0.05-1, and the stripping stage is 2-8; the stripping solution includes one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, phosphoric acid solution, acetic acid solution, and citric acid solution.

8. The method for treating a laterite nickel ore solution having high calcium and magnesium contents according to claim 1, wherein: In step S5, the saponification stage is 1-2.

9. A nickel-cobalt salt crystal obtained by the treatment method according to any one of claims 1 to 8.

10. Use of the nickel-cobalt salt crystal according to claim 9 in a battery.

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