A process for the extraction of impurities from a mixed ore leach solution

Abstract

This invention relates to a method for extracting and removing impurities from a mixed ore leaching solution. First, a mixed ore of nickel sulfide and laterite nickel is leached with perchloric acid to obtain a leaching solution. Perchloric acid itself has strong oxidizing properties, therefore no pressure or oxidant needs to be added during leaching. By using a synergistic extractant, the selectivity of impurity ions is good and the extraction rate is high. The synergistic extractant can also be recycled. Without introducing new impurity ions, the organic phase is saponified from sodium soap to nickel soap, and the mixed ore leaching solution is then extracted to finally obtain a high-purity nickel sulfate solution. The method is simple to operate, has good impurity removal effect, and is suitable for industrial-scale production.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, specifically to a method for extracting and removing impurities from mixed ore leachate. Background Technology

[0002] Currently, the explosive growth of the new energy industry has led to a surge in demand for high-purity battery-grade nickel sulfate solution, necessitating the rational development and utilization of nickel resources. In recent years, domestic high-quality nickel sulfide ore resources have gradually depleted, forcing development efforts to shift towards low-quality laterite nickel ore or mixed ore of nickel sulfide and laterite, which have large reserves but are difficult to utilize.

[0003] Acid leaching is a relatively mature process in the industry for treating limonite-type laterite nickel ore and sulfide ores. However, while valuable metals such as nickel and cobalt are leached out, impurity metal ions such as iron, aluminum, manganese, copper, zinc, calcium, and magnesium will also dissolve into the leaching solution. Therefore, removing impurities from the leaching solution to obtain a high-purity nickel sulfate solution has a broad market and promising prospects.

[0004] CN 116043032A discloses a method for processing nickel-cobalt sulfide. The method includes: using nickel-cobalt sulfide, an intermediate product of laterite nickel ore hydrometallurgy, as raw material; adding an oxidant, a catalyst, and a neutralizing agent; controlling the reaction conditions; performing selective oxidative leaching and preliminary impurity removal to separate nickel from impurities, obtaining a nickel-containing solution; subjecting the nickel-containing solution to deep extraction to obtain a nickel sulfate solution; and evaporating and crystallizing the resulting nickel sulfate crystals; loading an organic phase for back-extraction; returning the organic phase to the extraction and impurity removal step; and returning the impurity sulfate solution to the selective oxidative leaching step. This invention can achieve deep extraction and impurity removal, but requires the addition of an oxidant during acid leaching, thus increasing raw material costs.

[0005] CN 115180653A discloses a method for the efficient utilization of a combination of limonite and magnesian laterite nickel ore, comprising: S1, leaching the residue obtained by acid leaching of limonite low-nickel laterite nickel ore, followed by acid leaching under normal pressure and filtration to obtain a first leaching solution; S2, smelting the laterite nickel ore by pyrometallurgy to obtain a nickel-iron alloy; S3, leaching the nickel-iron alloy by mixing the first leaching solution with acid and water to obtain a second leaching solution; S4, adding a purification agent to the second leaching solution for purification and filtration to obtain a high-purity ferrous solution and nickel-cobalt sulfide products;

[0006] S5. The high-purity ferrous solution is added to an oxidant and a phosphorus source to synthesize ferric phosphate dihydrate. However, this method still carries the risk of residual impurity metal ions in the resulting nickel sulfate solution.

[0007] Therefore, in view of the shortcomings of the existing technology, there is a need to provide a method for extracting impurities from leachate that is simple to operate, requires no addition of oxidants, has a good impurity removal effect, and does not introduce new impurities. Summary of the Invention

[0008] The purpose of this invention is to provide a method for extracting impurities from a mixed ore leaching solution. This method uses perchloric acid to leach metal ions from a mixed ore of nickel sulfide and laterite nickel, and extracts and removes impurity ions from the leaching solution without introducing new impurities. It has the advantages of good impurity removal effect and simple operation.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] This invention provides a method for extracting and removing impurities from a mixed mineral leachate, the method comprising the following steps:

[0011] (1) The mixed ore of nickel sulfide and laterite nickel was leached with perchloric acid, and the resulting leachate was concentrated to obtain the mixed ore leachate.

[0012] (2) The first organic phase is mixed with the mixed ore leaching solution obtained in step (1) for the first extraction, and after phase separation, a nickel-magnesium raffinate is obtained.

[0013] (3) The second organic phase is mixed with the nickel-magnesium raffinate obtained in step (2) for a second extraction, and a nickel sulfate solution is obtained after phase separation;

[0014] Step (2) The first organic phase is the organic phase obtained by converting the organic phase composed of the first synergistic extractant and the diluent into nickel soap using sodium soap; Step (3) The second organic phase is the organic phase obtained by converting the organic phase composed of the second synergistic extractant and the diluent into nickel soap using sodium soap.

[0015] The method for extracting and removing impurities from mixed ore leaching solution provided by this invention firstly uses perchloric acid to leach a mixed ore of nickel sulfide and laterite nickel to obtain a leaching solution. Perchloric acid itself has strong oxidizing properties, so there is no need to pressurize or add oxidants during leaching. By adopting a synergistic extractant, compared with a single extractant, the selectivity of impurity ions is better and the extraction rate is higher. Without introducing new impurity ions, the organic phase is saponified from sodium soap to nickel soap, and the mixed ore leaching solution is subjected to two-stage extraction to finally obtain a high-purity nickel sulfate solution.

[0016] In this invention, the saponification of the organic phase is changed from sodium soap to nickel soap. Specifically, sodium soap is first used to introduce sodium ions into the organic phase. The organic phase then comes into contact with the aqueous phase and undergoes ion exchange. Impurity ions in the aqueous phase enter the organic phase, and sodium ions in the organic phase enter the aqueous phase. The final aqueous phase is a solution containing nickel and sodium. After sodium soaping, nickel ions are first used to exchange with sodium ions to convert the cations in the organic phase into nickel ions. Then, it comes into contact with the aqueous phase and undergoes ion exchange again. Nickel ions enter the aqueous phase, and impurity ions enter the organic phase. At this point, the solution contains only nickel ions, thus obtaining a high-purity nickel sulfate solution.

[0017] Preferably, the concentration of perchloric acid in step (1) is 1-8 mol / L, for example, it can be 1 mol / L, 3 mol / L, 5 mol / L, 6 mol / L or 8 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] Preferably, the concentration process in step (1) is carried out using an ion exchange resin.

[0019] In this invention, ion exchange resin is used for concentration treatment. Ion exchange resin itself has anions and cations. Cation exchange resin is composed of sulfonic acid groups, carboxyl groups and phenol groups. The hydrogen ions in it will exchange with metal ions in the solution, exchanging useful metal ions onto the resin and exchanging hydrogen ions into the solution, leaving impurity ions in the solution. The useful metal ions on the resin are then desorbed and concentrated using sulfuric acid as a desorbing agent, thereby achieving the effect of preliminary impurity removal and concentration.

[0020] In addition, it should be noted that the sulfate ions in the nickel sulfate solution obtained by the present invention come from sulfate obtained by oxidation of sulfur in nickel sulfide ore on the one hand, and from sulfuric acid, the desiccant in the concentration treatment on the other hand. The leachate in step (1) is concentrated, and the chloride ions therein have been converted into sulfate ions during resin desiccation.

[0021] Preferably, the concentration process in step (1) is carried out at room temperature.

[0022] Preferably, in the concentration process described in step (1), the flow rate of the ion exchange resin bed is controlled to be 1-8 BV / h, for example, it can be 1 BV / h, 3 BV / h, 5 BV / h, 6 BV / h or 8 BV / h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] Preferably, based on a total mass percentage of 100 wt%, the first synergistic extractant comprises 10-60 wt% of the organic phase composed of the first synergistic extractant and the diluent, with the remainder being the diluent.

[0024] The mass percentage of the first synergistic extractant is 10-60 wt%, for example, it can be 10 wt%, 20 wt%, 30 wt%, 40 wt% or 60 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the first synergistic extractant comprises P204 and P507.

[0026] Preferably, based on a total mass percentage of 100 wt%, the first synergistic extractant contains 10-90 wt% P2O4 and the balance is P5O7.

[0027] The mass percentage of P204 in the first synergistic extractant is 10-90 wt%, for example, it can be 10 wt%, 30 wt%, 50 wt%, 70 wt% or 90 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, based on a total mass percentage of 100 wt%, the second synergistic extractant comprises 10-60 wt% of the organic phase composed of the second synergistic extractant and the remainder is the diluent.

[0029] The mass percentage of the second synergistic extractant is 10-60 wt%, for example, it can be 10 wt%, 20 wt%, 30 wt%, 40 wt% or 60 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0030] Preferably, the second synergistic extractant comprises P507 and C272.

[0031] Preferably, based on a total mass percentage of 100 wt%, the second synergistic extractant contains 10-90 wt% P507 and the balance is C272.

[0032] In the second synergistic extractant, the mass percentage of P507 is 10-90 wt%, for example, it can be 10 wt%, 30 wt%, 50 wt%, 70 wt% or 90 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] Preferably, the diluent comprises sulfonated kerosene.

[0034] Preferably, the degree of saponification of the sodium soap is 10%-70%, for example, it can be 10%, 20%, 50%, 60% or 70%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] Preferably, the degree of saponification of the nickel soap is 10%-80%, for example, it can be 10%, 30%, 60%, 70% or 80%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] Preferably, the sodium sulfate solution obtained after the nickel soap is recycled.

[0037] Preferably, in the mixed ore leaching solution of step (1), the concentration of nickel ions is 80-120 g / L, the concentration of cobalt ions is 5-15 g / L, and the total concentration of impurity metal ions is 20-30 g / L.

[0038] The nickel ion concentration in the mixed ore leachate is 80-120 g / L, for example, it can be 80 g / L, 90 g / L, 100 g / L, 110 g / L or 120 g / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] The cobalt ion concentration in the mixed mineral leachate is 5-15 g / L, for example, it can be 5 g / L, 8 g / L, 10 g / L, 12 g / L or 15 g / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] The total concentration of impurity metal ions in the mixed mineral leachate is 20-30 g / L, for example, it can be 20 g / L, 22 g / L, 25 g / L, 28 g / L or 30 g / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] Preferably, the impurity metal ions include manganese ions, magnesium ions, copper ions, and zinc ions.

[0042] Preferably, the impurity metal ions also include calcium ions.

[0043] Preferably, in step (2), the extraction ratio of the first extraction to O / A is (0.2-5):1, for example, it can be 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1 or 5:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0044] Preferably, the temperature of the first extraction in step (2) is 20-70°C, for example, it can be 20°C, 30°C, 50°C, 60°C or 70°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] Preferably, the mixing speed of the first extraction in step (2) is 150-450 rpm, for example, it can be 150 rpm, 200 rpm, 250 rpm, 350 rpm or 450 rpm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0046] Preferably, the extraction time in step (2) is 0.05-0.5h, for example, it can be 0.05h, 0.1h, 0.2h, 0.3h or 0.5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0047] Preferably, the first extraction in step (2) is a 2-8 stage countercurrent extraction, for example, it can be 2 stages, 4 stages, 6 stages or 8 stages, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0048] Preferably, after phase separation in step (2), an organic phase containing impurities is obtained. The organic phase containing impurities is subjected to a first back-extraction and regeneration to obtain a first synergistic extractant, which is then recycled.

[0049] The extractant used in the extraction system of this invention can be recycled, and the back-extraction operation is simple.

[0050] Preferably, the concentration of the acid used in the first back-extraction is 0.1-6 mol / L, for example, it can be 0.1 mol / L, 1 mol / L, 3 mol / L, 5 mol / L or 6 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0051] Preferably, the first synergistic extractant is washed with pure water.

[0052] Preferably, the extraction ratio O / A, temperature, mixing speed and time of the second extraction in step (3) are the same as those of the first extraction in step (2).

[0053] Preferably, the second extraction in step (3) is a 2-8 stage countercurrent extraction, for example, it can be 2 stages, 4 stages, 6 stages or 8 stages, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0054] Preferably, after phase separation in step (3), an organic phase containing impurities is obtained. The organic phase containing impurities is subjected to a second back-extraction and regeneration to obtain a second synergistic extractant, which is then recycled.

[0055] Preferably, the concentration of the acid used in the second back-extraction is the same as the concentration of the acid used in the first back-extraction.

[0056] Preferably, the second synergistic extractant is washed with pure water.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The method for extracting and removing impurities from mixed ore leaching solutions provided by this invention firstly uses perchloric acid to leach a mixed ore of nickel sulfide and laterite nickel to obtain a leaching solution. Perchloric acid itself has strong oxidizing properties, so no pressure or oxidant needs to be added during leaching. By using a synergistic extractant, compared with a single extractant, the selectivity of impurity ions is better and the extraction rate is higher. The synergistic extractant can also be recycled. Without introducing new impurity ions, the organic phase is saponified from sodium soap to nickel soap, and the mixed ore leaching solution is extracted to finally obtain a high-purity nickel sulfate solution. The method is simple to operate, has a good impurity removal effect, and is suitable for industrial-scale production. Detailed Implementation

[0059] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0060] Example 1

[0061] This embodiment provides a method for extracting and removing impurities from a mixed mineral leachate, the method comprising the following steps:

[0062] (1) A mixture of nickel sulfide and laterite nickel ore was leached with perchloric acid at a concentration of 5 mol / L. The resulting leachate was concentrated at room temperature using an ion exchange resin. The flow rate of the ion exchange resin bed was controlled at 5 BV / h to obtain a mixed ore leachate. The mixed ore leachate contained nickel ion concentrations of 110.25 g / L, cobalt ion concentrations of 10.58 g / L, manganese ion concentrations of 15.64 g / L, magnesium ion concentrations of 6.39 g / L, copper ion concentrations of 0.32 g / L, and zinc ion concentrations of 2.74 g / L.

[0063] (2) The organic phase composed of P204, P507 and sulfonated kerosene was subjected to 60% sodium soap with 10mol / L sodium hydroxide, and the organic phase after sodium soap was subjected to 70% nickel soap with nickel sulfate to obtain the first organic phase. The first organic phase was mixed with the mixed mineral leachate obtained in step (1) and subjected to three-stage countercurrent extraction. The extraction ratio O / A was 2:1, the temperature was 40℃, the mixing speed was 250rpm, and the time was 0.2h. After phase separation, the raffinate containing nickel and magnesium and the organic phase containing impurities were obtained. The extraction rate of manganese was 98%, the extraction rate of zinc was 95%, the extraction rate of copper was 90%, and the extraction rate of cobalt was 80%.

[0064] The organic phase containing impurities was subjected to a first back-extraction and regeneration using sulfuric acid with a concentration of 3 mol / L. The resulting P204 and P507 were then recycled after being washed with pure water.

[0065] Based on a total mass percentage of 100 wt%, the organic phase contains 30 wt% of P204 and P507, with the remainder being sulfonated kerosene; based on a total mass percentage of 100 wt%, P204 contains 50 wt% of P204, with the remainder being P507.

[0066] (3) The organic phase composed of P507, C272 and sulfonated kerosene was subjected to 40% sodium soap with 10 mol / L sodium hydroxide, and the organic phase after sodium soap was subjected to 50% nickel soap with nickel sulfate to obtain a second organic phase. The second organic phase was mixed with the nickel-magnesium raffinate obtained in step (2) and subjected to three-stage countercurrent extraction. The extraction conditions were the same as in step (2). After phase separation, a nickel sulfate solution and an organic phase containing impurities were obtained. The organic phase containing impurities was subjected to a second back-extraction and regeneration with sulfuric acid of 3 mol / L. The obtained P507 and C272 were washed with pure water and then recycled.

[0067] Based on a total mass percentage of 100 wt%, the organic phase contains 30 wt% of P507 and C272, with the remainder being sulfonated kerosene; based on a total mass percentage of 100 wt%, P507 contains 50 wt% of P507, with the remainder being C272.

[0068] The purity of the nickel sulfate solution obtained in this embodiment can reach 99.95%, indicating that the method described above achieves efficient extraction and impurity removal from mixed mineral leachate.

[0069] Example 2

[0070] This embodiment provides a method for extracting and removing impurities from a mixed mineral leachate, the method comprising the following steps:

[0071] (1) A mixture of nickel sulfide and laterite nickel ore was leached with 1 mol / L perchloric acid. The resulting leachate was concentrated at room temperature using an ion exchange resin. The flow rate of the ion exchange resin bed was controlled at 1 BV / h to obtain a mixed ore leachate. The mixed ore leachate contained nickel ion concentrations of 83.04 g / L, cobalt ion concentrations of 10.14 g / L, manganese ion concentrations of 13.23 g / L, magnesium ion concentrations of 5.69 g / L, copper ion concentrations of 0.28 g / L, zinc ion concentrations of 1.92 g / L, and calcium ion concentrations of 0.45 g / L.

[0072] (2) The organic phase composed of P204, P507 and sulfonated kerosene was subjected to 10% sodium soap with 10 mol / L sodium hydroxide. The organic phase after sodium soap was subjected to 10% nickel soap with nickel sulfate to obtain the first organic phase. The first organic phase was mixed with the mixed mineral leaching solution obtained in step (1) and subjected to 8-stage countercurrent extraction. The extraction ratio O / A was 0.2:1, the temperature was 20℃, the mixing speed was 450 rpm, and the time was 0.5 h. After phase separation, the raffinate containing nickel and magnesium and the organic phase containing impurities were obtained. The extraction rate of manganese was 98%, the extraction rate of zinc was 95%, the extraction rate of copper was 95%, the extraction rate of calcium was 95%, and the extraction rate of cobalt was 80%.

[0073] The organic phase containing impurities was subjected to a first back-extraction and regeneration using sulfuric acid with a concentration of 0.1 mol / L. The resulting P204 and P507 were washed with pure water and then recycled.

[0074] Based on a total mass percentage of 100 wt%, the organic phase contains 20 wt% of P204 and P507, with the remainder being sulfonated kerosene; based on a total mass percentage of 100 wt%, P204 contains 10 wt% of P204, with the remainder being P507.

[0075] (3) The organic phase composed of P507, C272 and sulfonated kerosene was subjected to 10% sodium soap with 10 mol / L sodium hydroxide. The organic phase after sodium soap was subjected to 10% nickel soap with nickel sulfate to obtain a second organic phase. The second organic phase was mixed with the raffinate containing nickel and magnesium obtained in step (2) and subjected to 8-stage countercurrent extraction. The extraction conditions were the same as in step (2). After phase separation, a nickel sulfate solution and an organic phase containing impurities were obtained. The organic phase containing impurities was subjected to a second back-extraction and regeneration with sulfuric acid with a concentration of 0.1 mol / L. The obtained P507 and C272 were recycled after being washed with pure water.

[0076] Based on a total mass percentage of 100 wt%, the organic phase contains 20 wt% of P507 and C272, with the remainder being sulfonated kerosene; based on a total mass percentage of 100 wt%, P507 contains 10 wt% of P507, with the remainder being C272.

[0077] The purity of the nickel sulfate solution obtained in this embodiment can reach 99.9%, indicating that the method described above achieves efficient extraction and impurity removal from mixed mineral leachate.

[0078] Example 3

[0079] This embodiment provides a method for extracting and removing impurities from a mixed mineral leachate, the method comprising the following steps:

[0080] (1) A mixture of nickel sulfide and laterite nickel ore was leached with perchloric acid at a concentration of 8 mol / L. The resulting leachate was concentrated at room temperature using an ion exchange resin. The flow rate of the ion exchange resin bed was controlled at 8 BV / h to obtain a mixed ore leachate. The mixed ore leachate contained nickel ion concentrations of 116.5 g / L, cobalt ion concentrations of 12.09 g / L, manganese ion concentrations of 18.51 g / L, magnesium ion concentrations of 4.18 g / L, copper ion concentrations of 0.66 g / L, zinc ion concentrations of 2.59 g / L, and calcium ion concentrations of 0.37 g / L.

[0081] (2) The organic phase composed of P204, P507 and sulfonated kerosene was subjected to 70% sodium soap with 10mol / L sodium hydroxide, and the organic phase after sodium soap was subjected to 80% nickel soap with nickel sulfate to obtain the first organic phase. The first organic phase was mixed with the mixed mineral leachate obtained in step (1) and subjected to two-stage countercurrent extraction. The extraction ratio O / A was 5:1, the temperature was 70℃, the mixing speed was 150rpm, and the time was 0.05h. After phase separation, the raffinate containing nickel and magnesium and the organic phase containing impurities were obtained. The extraction rate of manganese was 98%, the extraction rate of zinc was 98%, the extraction rate of copper was 98%, the extraction rate of calcium was 95%, and the extraction rate of cobalt was 95%.

[0082] The organic phase containing impurities was subjected to a first back-extraction and regeneration using sulfuric acid with a concentration of 6 mol / L. The resulting P204 and P507 were recycled after being washed with pure water.

[0083] Based on a total mass percentage of 100 wt%, the organic phase contains 60 wt% of P204 and P507, with the remainder being sulfonated kerosene; based on a total mass percentage of 100 wt%, P204 contains 90 wt% of P204, with the remainder being P507.

[0084] (3) The organic phase composed of P507, C272 and sulfonated kerosene was subjected to 70% sodium soap with 10mol / L sodium hydroxide, and the organic phase after sodium soap was subjected to 80% nickel soap with nickel sulfate to obtain a second organic phase. The second organic phase was mixed with the raffinate containing nickel and magnesium obtained in step (2) and subjected to two-stage countercurrent extraction. The extraction conditions were the same as in step (2). After phase separation, a nickel sulfate solution and an organic phase containing impurities were obtained. The organic phase containing impurities was subjected to a second back-extraction and regeneration with sulfuric acid with a concentration of 6mol / L. The obtained P507 and C272 were recycled after being washed with pure water.

[0085] Based on a total mass percentage of 100 wt%, the organic phase contains 60 wt% of P507 and C272, with the remainder being sulfonated kerosene; based on a total mass percentage of 100 wt%, P507 contains 90 wt% of P507, with the remainder being C272.

[0086] The purity of the nickel sulfate solution obtained in this embodiment can reach 99.94%, indicating that the method described above achieves efficient extraction and impurity removal from mixed mineral leachate.

[0087] Example 4

[0088] This embodiment provides a method for extracting and removing impurities from a mixed mineral leaching solution. The difference from Embodiment 1 is that the total mass percentage of P204 and P507 in the organic phase of step (2) is adjusted to 5 wt%, and the mass percentage of P204 in P204 and P507 is adjusted to 5 wt%. The total mass percentage of P507 and C272 in the organic phase of step (3) is adjusted to 5 wt%, and the mass percentage of P507 in P507 and C272 is adjusted to 5 wt%. All other aspects are the same as in Embodiment 1.

[0089] In this embodiment, the content of the synergistic extractant in the organic phase is too low, and the proportion of the two extractants in the synergistic extractant exceeds the limit range, which will affect the extraction effect. After the first extraction, the extraction rate of manganese is 60%, the extraction rate of zinc is 90%, the extraction rate of copper is 90%, and the extraction rate of cobalt is 70%; the purity of the obtained nickel sulfate solution is 90%.

[0090] Example 5

[0091] This embodiment provides a method for extracting and removing impurities from a mixed mineral leaching solution. The difference from Embodiment 1 is that the total mass percentage of P204 and P507 in the organic phase of step (2) is adjusted to 65 wt%, and the mass percentage of P204 in P204 and P507 is adjusted to 95 wt%. The total mass percentage of P507 and C272 in the organic phase of step (3) is adjusted to 65 wt%, and the mass percentage of P507 in P507 and C272 is adjusted to 95 wt%. All other aspects are the same as in Embodiment 1.

[0092] In this embodiment, due to the excessively high content of the co-extractant in the organic phase, the remaining portion of the extractant after extracting impurity ions will extract a large amount of nickel ions. Furthermore, the excessively high concentration of P507 in the organic phase described in step (3) results in a lack of selective extraction for impurity magnesium ions, causing magnesium ions to remain in the solution and leading to a decrease in the purity of the nickel sulfate solution. After the first extraction, the extraction rates of manganese, zinc, copper, and cobalt are 99.9%, 98%, 95%, and 95%, respectively. The purity of the resulting nickel sulfate solution is 99.2%.

[0093] Example 6

[0094] This embodiment provides a method for extracting impurities from mixed mineral leachate. The difference from Embodiment 1 is that, except for adjusting the O / A ratio of the countercurrent extraction in step (2) to 0.1:1, the rest is the same as in Embodiment 1.

[0095] In this embodiment, the extraction efficiency decreased due to the low O / A ratio of the countercurrent extraction. After the first extraction, the extraction rate of manganese was 40%, the extraction rate of zinc was 93%, the extraction rate of copper was 88%, and the extraction rate of cobalt was 75%. The purity of the obtained nickel sulfate solution was 90.5%.

[0096] Example 7

[0097] This embodiment provides a method for extracting impurities from mixed mineral leachate. The difference from Embodiment 1 is that, except for adjusting the O / A ratio of the countercurrent extraction in step (2) to 5.5:1, the rest is the same as in Embodiment 1.

[0098] In this embodiment, because the extraction ratio of countercurrent extraction is too high (O / A), the excess extractant will extract all ions in the aqueous phase, thus failing to remove impurity ions.

[0099] Comparative Example 1

[0100] This comparative example provides a method for extracting and removing impurities from a mixed mineral leaching solution. The difference from Example 1 is that the perchloric acid in step (1) is replaced with sulfuric acid, while the rest is the same as in Example 1.

[0101] In this comparative example, because sulfuric acid leaching of the mixed ore is used, an additional oxidant needs to be added for leaching, resulting in higher production costs.

[0102] Comparative Example 2

[0103] This comparative example provides a method for extracting and removing impurities from a mixed mineral leaching solution. The difference from Example 1 is that the first synergistic extractant composed of P204 and P507 is replaced by an equal mass of a single P204 extractant, while the rest is the same as in Example 1.

[0104] In this comparative example, the extraction efficiency was significantly reduced due to the use of a single extractant for the first extraction. After the first extraction, the extraction rates of manganese were 90%, zinc 93%, copper 86%, and cobalt 60%; the purity of the resulting nickel sulfate solution was 90%.

[0105] Comparative Example 3

[0106] This comparative example provides a method for extracting and removing impurities from a mixed mineral leaching solution. The difference from Example 1 is that the second synergistic extractant composed of P507 and C272 is replaced by an equal mass of a single P507 extractant. All other aspects are the same as in Example 1.

[0107] In this comparative example, the use of a single P507 extractant for the second extraction significantly reduced the extraction efficiency of magnesium ions, resulting in a decrease in the purity of the nickel sulfate solution. The purity of the obtained nickel sulfate solution was 95%.

[0108] In summary, the method for extracting and removing impurities from mixed ore leaching solutions provided by this invention first uses perchloric acid to leach a mixed ore of nickel sulfide and laterite nickel to obtain a leaching solution. Perchloric acid itself has strong oxidizing properties, so no pressure or oxidant needs to be added during leaching. By using a synergistic extractant, compared with a single extractant, the selectivity of impurity ions is better and the extraction rate is higher. The synergistic extractant can also be recycled. Without introducing new impurity ions, the organic phase is saponified from sodium soap to nickel soap, and the mixed ore leaching solution is extracted to finally obtain a high-purity nickel sulfate solution. The method is simple to operate, has a good impurity removal effect, and is suitable for industrial-scale production.

[0109] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for extracting and removing impurities from a mixed mineral leachate, characterized in that, The method includes the following steps: (1) The mixed ore of nickel sulfide and laterite nickel was leached with perchloric acid, and the resulting leachate was concentrated to obtain the mixed ore leachate. (2) The first organic phase is mixed with the mixed ore leaching solution obtained in step (1) for the first extraction, and after phase separation, a raffinate containing nickel and magnesium is obtained; (3) The second organic phase is mixed with the nickel-magnesium raffinate obtained in step (2) for a second extraction, and after phase separation, a nickel sulfate solution is obtained; Step (2) The first organic phase is the organic phase obtained after the organic phase composed of the first synergistic extractant and the diluent is converted into nickel soap by sodium soap; based on a total mass percentage of 100wt%, the first synergistic extractant in the organic phase composed of the first synergistic extractant and the diluent is 10-60wt%, and the remainder is the diluent; the first synergistic extractant includes P204 and P507; based on a total mass percentage of 100wt%, P204 in the first synergistic extractant is 10-90wt%, and the remainder is P507; Step (3) The second organic phase is the second organic phase obtained after the organic phase composed of the second synergistic extractant and the diluent is converted into nickel soap by sodium soap; based on a total mass percentage of 100wt%, the second synergistic extractant in the organic phase composed of the second synergistic extractant and the diluent is 10-60wt%, and the remainder is the diluent; the second synergistic extractant includes P507 and C272; based on a total mass percentage of 100wt%, P507 in the second synergistic extractant is 10-90wt%, and the remainder is C272.

2. The method according to claim 1, characterized in that, The concentration of perchloric acid in step (1) is 1-8 mol / L.

3. The method according to claim 1, characterized in that, The concentration process in step (1) is carried out using ion exchange resin.

4. The method according to claim 1, characterized in that, In step (1), the flow rate of the ion exchange resin bed is controlled to be 1-8 BV / h during the concentration process.

5. The method according to claim 1, characterized in that, The diluent includes sulfonated kerosene.

6. The method according to claim 1, characterized in that, The degree of saponification of the sodium soap is 10%-70%.

7. The method according to claim 1, characterized in that, The saponification degree of the nickel soap is 10%-80%.

8. The method according to claim 1, characterized in that, In the mixed ore leaching solution described in step (1), the concentration of nickel ions is 80-120 g / L, the concentration of cobalt ions is 5-15 g / L, and the total concentration of impurity metal ions is 20-30 g / L.

9. The method according to claim 8, characterized in that, The impurity metal ions include manganese ions, magnesium ions, copper ions, and zinc ions.

10. The method according to claim 9, characterized in that, The impurity metal ions also include calcium ions.

11. The method according to claim 1, characterized in that, Step (2) The extraction ratio of the first extraction is (0.2-5):

1.

12. The method according to claim 1, characterized in that, Step (2) The temperature of the first extraction is 20-70℃.

13. The method according to claim 1, characterized in that, Step (2) The mixing speed of the first extraction is 150-450 rpm.

14. The method according to claim 1, characterized in that, Step (2) The first extraction time is 0.05-0.5h.

15. The method according to claim 1, characterized in that, Step (2) The first extraction is a 2-8 stage countercurrent extraction.

16. The method according to claim 1, characterized in that, After phase separation in step (2), an organic phase containing impurities is obtained. The organic phase containing impurities is subjected to a first back-extraction and regeneration to obtain a first synergistic extractant, which is then recycled.

17. The method according to claim 16, characterized in that, The concentration of the acid used in the first back-extraction is 0.1-6 mol / L.

18. The method according to claim 1, characterized in that, In step (3), the extraction ratio of the second extraction, the O / A ratio, temperature, mixing speed, and time are the same as those of the first extraction in step (2).

19. The method according to claim 1, characterized in that, Step (3) The second extraction is a 2-8 stage countercurrent extraction.

20. The method according to claim 17, characterized in that, After phase separation in step (3), an organic phase containing impurities is obtained. The organic phase containing impurities is subjected to a second back-extraction and regeneration to obtain a second synergistic extractant, which is then recycled.

21. The method according to claim 20, characterized in that, The concentration of the acid used in the second back-extraction is the same as the concentration of the acid used in the first back-extraction.