Method for preparing cobalt chloride from cobalt raw material lixivium

Abstract

The invention relates to a method for preparing cobalt chloride from a cobalt raw material leaching solution, which comprises the following steps: (1) carrying out reduction leaching on crude cobalt hydroxide slurry by using a hydrochloric acid solution and hydrogen peroxide to obtain a leaching solution; (2) carrying out primary impurity removal on the leachate obtained in the step (1), and carrying out extraction impurity removal by using a P04 organic extraction agent, so as to obtain raffinate; and (3) pre-treating the raffinate obtained in the step (2), then extracting by adopting an N263 organic extraction agent, and sequentially washing and reversely extracting the obtained loaded organic phase to obtain a cobalt chloride finished product liquid. The hydrochloric acid solution and hydrogen peroxide are adopted for reduction leaching, the purity of cobalt chloride can be guaranteed, and introduction of sulfur is avoided; the N263 organic extraction agent is adopted to extract cobalt, the selectivity on cobalt is high, the extraction capacity on impurities such as Ni / Mg is basically avoided, saponification is not needed due to organic matter, direct extraction can be achieved, and finally the cobalt chloride finished product liquid with the low impurity content is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of extraction, and relates to a method for preparing cobalt chloride from cobalt raw material leaching solution. BACKGROUND

[0002] Cobalt is an important strategic metal, which is widely used in lithium battery cathode material, magnetic material and catalyst field. High-purity cobalt chloride or cobalt sulfate is a key precursor for preparing the above high-end materials. Generally, after acid dissolution and reduction leaching of cobalt raw materials such as cobalt hydroxide, a solution mainly containing cobalt sulfate or cobalt chloride can be obtained. However, the leaching solution contains impurity elements such as nickel, manganese, magnesium and copper, and the presence of these impurities will seriously affect the performance of the final cobalt product, so an effective process is needed for deep purification.

[0003] In the existing industrialized purification process, solvent extraction technology is widely used due to its continuous operation, strong selectivity, high recovery rate and other advantages. The typical process flow of impurity removal and preparation of cobalt sulfate or cobalt chloride solution usually consists of two steps: first, P204 extractant is used to preliminarily remove calcium, copper, zinc, manganese and other impurities in the leaching solution; then, P507 extractant is used for selective extraction and enrichment of cobalt to achieve deep separation of cobalt and remaining impurities. For example, CN111056576A discloses a method for preparing battery-grade cobalt sulfate from low-grade cobalt sulfide tailings, which comprises the following steps: mixing the calcine formed by roasting low-grade cobalt with raffinate and then flowing into the leaching system; after leaching, the slurry is subjected to liquid-solid separation by a filter, and the filtrate and washing water are mixed to form a pre-extraction liquid; the pre-extraction liquid is introduced into a copper extraction system; part of the raffinate is introduced into a impurity removal device for impurity removal, and then introduced into a impurity removal filter for washing; the obtained impurity removal filtrate is cooled and then introduced into a P204 extraction system; the P204 raffinate obtained by extraction is introduced into a P507 extraction system; and the obtained cobalt sulfate solution is subjected to oil removal, concentration, crystallization and drying to obtain a product with low impurity content. CN112760498A discloses a method for preparing high-purity cobalt sulfate and recovering germanium by segmental iron removal, which comprises the following steps: adding white alloy powder into sulfuric acid for one-stage leaching; after slurring the one-stage leaching residue, adding sulfuric acid and then bubbling oxygen for leaching; bubbling air or adding hydrogen peroxide into the one-stage leaching solution after heating to remove iron; adding hydrogen peroxide and sodium carbonate into the once-iron-removed solution for secondary iron removal; and performing impurity extraction and cobalt extraction on the pressure filtration liquid to obtain a cobalt sulfate solution.

[0004] However, the cobalt raw material solution obtained by the upstream leaching process usually has a high cobalt concentration, and a large amount of P507 organic phase needs to be saponified, which consumes a large amount of alkali. Therefore, in order to reduce the high alkali consumption generated in the P507 saponification section, it is urgent to develop a cobalt raw material purification method which is simple in process, easy to operate and can significantly reduce alkali consumption.

[0005] The new extraction system without saponification can efficiently extract cobalt, which is an effective way to solve the above problems. The quaternary ammonium salt extraction agent such as N263 is an anion extraction agent, and its extraction mechanism is different from the cation exchange of P507. - In a suitable chloride system, N263 can directly bind with CoCl4 2- complex anion to form a complex, so that cobalt is extracted, and the whole process does not need to be saponified in advance. If N263 can be successfully used to replace P507 for the purification of high-cobalt raw material liquid, the saponification process can be directly omitted, the alkali consumption problem can be fundamentally eliminated, the process can be simplified, and the production cost can be significantly reduced, so that the method has important industrial application prospects. SUMMARY

[0006] In view of the problems in the prior art, the purpose of the present application is to provide a method for preparing cobalt chloride from cobalt raw material leaching solution, which solves the problem of high alkali consumption in the extraction process of preparing cobalt chloride from cobalt raw material leaching solution, and significantly reduces the production cost.

[0007] To achieve the purpose of the present application, the following technical solutions are adopted:

[0008] The present application provides a method for preparing cobalt chloride from cobalt raw material leaching solution, which comprises the following steps:

[0009] (1) The crude cobalt hydroxide slurry is reduced and leached by using hydrochloric acid solution and hydrogen peroxide to obtain a leaching solution;

[0010] (2) The leaching solution obtained in step (1) is subjected to preliminary impurity removal and P04 organic extraction agent extraction to obtain a raffinate;

[0011] (3) The raffinate obtained in step (2) is subjected to pretreatment, and then extracted by using N263 organic extraction agent, and the obtained loaded organic phase is sequentially subjected to washing and stripping to obtain cobalt chloride product liquid.

[0012] The method for preparing cobalt chloride from cobalt raw material leaching solution provided by the present application first uses hydrochloric acid solution and hydrogen peroxide for reduction leaching, which can ensure the purity of cobalt chloride and avoid the introduction of sulfur, and can also reduce the addition amount of sodium chlorate, a reagent for subsequent pretreatment, which is a step of adding sodium chlorate for oxidation treatment before iron and aluminum removal in the traditional process; after extraction and impurity removal by using P04 organic extraction agent, N263 organic extraction agent is used for cobalt extraction, the extraction agent has high selectivity for cobalt and basically has no extraction ability for Ni / Mg and other impurities, and organic does not need to be saponified, so that direct extraction can be realized; finally, through washing and stripping, cobalt chloride product liquid with low impurity content is obtained, and no acid and alkali is consumed in the extraction process.

[0013] Preferably, the step of reduction leaching in step (1) specifically comprises: first adjusting the pH value of the crude cobalt hydroxide slurry to 1-1.5 with a hydrochloric acid solution, and then adding hydrogen peroxide for reduction leaching.

[0014] The pH value of the crude cobalt hydroxide slurry adjusted to 1-1.5 with a hydrochloric acid solution may be, for example, 1, 1.1, 1.2, 1.3 or 1.5, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0015] Preferably, the temperature at which the hydrogen peroxide is added is 60-90℃, for example, it may be 60℃, 65℃, 70℃, 80℃ or 90℃, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0016] Preferably, the amount of hydrogen peroxide added is such that the color of the leaching solution becomes red and the color of the filter residue becomes off-white.

[0017] Preferably, the time for the reduction leaching in step (1) is 2-4h, for example, it may be 2h, 2.5h, 3h, 3.5h or 4h, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0018] Preferably, the crude cobalt hydroxide slurry in step (1) is obtained by mixing crude cobalt hydroxide and water at a solid-liquid ratio of 1:(2-5), for example, it may be 1:2, 1:2.5, 1:3, 1:4 or 1:5, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0019] Preferably, the concentration of the hydrochloric acid solution in step (1) is 8-12mol / L, for example, it may be 8mol / L, 9mol / L, 10mol / L, 11mol / L or 12mol / L, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0020] Preferably, the step of preliminary impurity removal in step (2) specifically comprises: adding an alkali source to the leaching solution obtained in step (1) for mixing, and pressure filtering to obtain a preliminary impurity removal solution.

[0021] Preferably, the alkali source comprises a sodium hydroxide solution and / or a calcium hydroxide solution.

[0022] The step of preliminary impurity removal can remove iron and aluminum impurities in the leaching solution.

[0023] Preferably, the concentration of the sodium hydroxide solution is 8-12 mol / L, for example, it can be 8 mol / L, 9 mol / L, 10 mol / L, 11 mol / L or 12 mol / L, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0024] Preferably, the mass concentration of the calcium hydroxide solution is 20-25 wt%, for example, it can be 20 wt%, 21 wt%, 22 wt%, 23 wt% or 25 wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0025] Preferably, the temperature when the alkali source is added is 60-90℃, for example, it can be 60℃, 65℃, 70℃, 80℃ or 90℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0026] Preferably, the mixing time is 0.5-2h, for example, it can be 0.5h, 0.8h, 1h, 1.5h or 2h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0027] Preferably, the P204 organic extractant in step (2) comprises: P204 25-30%, and the balance is kerosene, based on a total volume fraction of 100%.

[0028] The volume fraction of P204 in the P04 organic extractant is 25-30%, for example, it can be 25%, 26%, 28%, 29% or 30%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0029] Preferably, the temperature for the impurity removal by extraction in step (2) is 20-40℃, for example, it can be 20℃, 25℃, 30℃, 35℃ or 40℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0030] Preferably, the organic to feed liquid ratio for the impurity removal by extraction in step (2) is (1.2-1.5):1, for example, it can be 1.2:1, 1.25:1, 1.3:1, 1.4:1 or 1.5:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0031] Preferably, the extraction series for the impurity removal by extraction in step (2) is 5-10 series, for example, it can be 5 series, 6 series, 7 series, 8 series, 9 series or 10 series.

[0032] The step of impurity removal by extraction can remove calcium impurities in the feed liquid.

[0033] Preferably, the pre-treatment step of step (3) specifically comprises: adding sodium chloride to the raffinate obtained in step (2) until the solution is saturated, and then adding a hydrochloric acid solution to acidify the solution to a pH value <0.

[0034] The pH value of the solution is <0, for example, it can be -0.281, -0.42, or -0.475, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0035] Preferably, the concentration of the hydrochloric acid solution is 0.23-0.3 mol / L, for example, it can be 0.23 mol / L, 0.25 mol / L, 0.27 mol / L, 0.28 mol / L, or 0.3 mol / L, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0036] Preferably, the concentration of N263 in the N263 organic extractant of step (3) is 150-400 g / L, for example, it can be 150 g / L, 180 g / L, 200 g / L, 250 g / L, 300 g / L, 350 g / L, or 400 g / L, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0037] Preferably, the organic reagent in the N263 organic extractant of step (3) comprises: 15-30% isooctanol, and the balance is sulfonated kerosene, based on a total volume fraction of 100%.

[0038] The volume fraction of isooctanol in the N263 organic extractant is 15-30%, for example, it can be 15%, 18%, 20%, 25%, or 30%, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0039] Preferably, the temperature of the extraction of step (3) is 20-40°C, for example, it can be 20°C, 25°C, 30°C, 35°C, or 40°C, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0040] Preferably, the organic to feed liquid ratio of the extraction of step (3) is (8-13):1, for example, it can be 8:1, 10.6:1, 11:1, 12:1, or 13:1, but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0041] Preferably, the extraction stage of the extraction of step (3) is 7-10 stages, for example, it can be 7 stages, 8 stages, 9 stages, or 10 stages.

[0042] Preferably, the washing liquid used in step (3) comprises a hydrochloric acid solution with a mass concentration of ≤1wt%, for example, it can be 1wt%, 0.8wt%, 0.5wt%, 0.3wt% or 0.1wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0043] Preferably, the temperature of the washing in step (3) is 20-40℃, for example, it can be 20℃, 25℃, 30℃, 35℃ or 40℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0044] Preferably, the washing in step (3) is 3-6 stages of countercurrent washing, for example, it can be 3 stages, 4 stages, 5 stages or 6 stages.

[0045] Preferably, the loading of organic to washing liquid in the washing in step (3) is (32-40):1, for example, it can be 32:1, 35:1, 36:1, 38:1 or 40:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0046] Preferably, the temperature of the stripping in step (3) is 20-40℃, for example, it can be 20℃, 25℃, 30℃, 35℃ or 40℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0047] Preferably, the number of stages of the stripping in step (3) is 10-20 stages, for example, it can be 10 stages, 12 stages, 15 stages, 17 stages or 20 stages, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0048] Preferably, the stripping liquid used in step (3) comprises pure water.

[0049] Preferably, the loading of organic to stripping liquid in the stripping in step (3) is (14-20):1, for example, it can be 14:1, 15:1, 16:1, 18:1 or 20:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0050] The numerical ranges described in the present application not only include the point values listed above, but also include any point values between the above numerical ranges that are not listed, and the present application does not exhaustively list the specific point values included in the range for the sake of brevity and simplicity.

[0051] Compared with the prior art, the present application has the following beneficial effects:

[0052] The application provides a method for preparing cobalt chloride from cobalt raw material leaching solution, which comprises the following steps: firstly, using hydrochloric acid solution and hydrogen peroxide to perform reduction leaching, so as to ensure the purity of cobalt chloride, avoid the introduction of sulfur, and reduce the amount of sodium chloride, a reagent for subsequent pretreatment; after using P04 organic extractant to perform extraction and impurity removal, using N263 organic extractant to extract cobalt, the selectivity of the extractant to cobalt is high, and the extractant has no extraction capacity to impurities such as Ni / Mg, so that the organic does not need to be saponified and direct extraction can be realized; finally, through washing and stripping, cobalt chloride product liquid with low impurity content is obtained, and no acid and alkali is consumed in the extraction process. DETAILED DESCRIPTION

[0053] The technical solutions of the application are further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the application, and should not be regarded as specific limitations on the application.

[0054] Embodiment 1

[0055] The embodiment provides a method for preparing cobalt chloride from cobalt raw material leaching solution, which comprises the following steps:

[0056] (1) using a hydrochloric acid solution with a concentration of 10 mol / L to adjust the pH value of crude cobalt hydroxide slurry to 1.2, then adding hydrogen peroxide at 70°C to perform reduction leaching for 3h, and stopping the reaction when the color of the leaching solution becomes red and the color of the filter residue becomes grayish white, to obtain a leaching solution; the crude cobalt hydroxide slurry is obtained by mixing crude cobalt hydroxide and water according to a solid-liquid ratio of 1:3;

[0057] (2) at 70°C, adding a sodium hydroxide solution with a concentration of 10 mol / L to the leaching solution obtained in step (1), mixing for 1h, and then performing pressure filtration to obtain a preliminary impurity removal liquid; then using P04 organic extractant to perform extraction and impurity removal on the preliminary impurity removal liquid, the temperature is 30°C, the organic phase to the liquid phase ratio is 1.3:1, and the extraction level is 9, to obtain a raffinate; the P04 organic extractant comprises: P204 26%, and the balance is kerosene, with the total volume fraction being 100%;

[0058] (3) after adding sodium chloride to the raffinate obtained in step (2) until the solution is saturated, adding a hydrochloric acid solution with a concentration of 0.27 mol / L to perform acidification, the amount of the hydrochloric acid solution is such that the pH value of the raffinate is adjusted to-0.42; then using N263 organic extractant to perform extraction, the temperature is 30°C, the organic phase to the liquid phase ratio is 10.6:1, and the extraction level is 9, to obtain a loaded organic phase; the concentration of N263 in the N263 organic extractant is 200g / L; the organic reagent in the N263 organic extractant comprises: isooctanol 20%, and the balance is sulfonated kerosene, with the total volume fraction being 100%;

[0059] The obtained loaded organic phase is washed by 5-stage countercurrent washing with 1wt% hydrochloric acid solution at 30°C, the ratio of loaded organic phase to hydrochloric acid solution being 35:1; then the washed loaded organic phase is back-extracted with pure water at 30°C, the stage number being 17, the ratio of loaded organic phase to pure water being 15:1, to obtain the cobalt chloride product liquid.

[0060] Example 2

[0061] The present example provides a method for preparing cobalt chloride from cobalt raw material leaching solution, which comprises the following steps:

[0062] (1) The pH value of crude cobalt hydroxide slurry is adjusted to 1.5 by using 8mol / L hydrochloric acid solution, then hydrogen peroxide is added at 60°C for reduction leaching for 4h, the reaction is ended when the color of leaching solution becomes red and the color of filter residue becomes grayish white, to obtain the leaching solution; the crude cobalt hydroxide slurry is obtained by mixing crude cobalt hydroxide with water at a solid-liquid ratio of 1:2;

[0063] (2) 8mol / L sodium hydroxide solution is added to the leaching solution obtained in step (1) at 60°C, mixed for 2h, and pressure filtration is performed to obtain the primary impurity removal liquid; then P04 organic extractant is used to extract and remove impurities from the primary impurity removal liquid, the temperature is 20°C, the ratio of organic phase to feed liquid is 1.2:1, the extraction stage number is 5, to obtain the raffinate; the P04 organic extractant comprises: P204 25%, the balance being kerosene, based on a total volume fraction of 100%;

[0064] (3) After sodium chloride is added to the raffinate obtained in step (2) until the solution is saturated, 0.23mol / L hydrochloric acid solution is added for acidification, the amount of hydrochloric acid solution added is to adjust the pH value of the raffinate to -0.281; then N263 organic extractant is used for extraction, the temperature is 20°C, the ratio of organic phase to feed liquid is 8:1, the extraction stage number is 7, to obtain the loaded organic phase; the concentration of N263 in the N263 organic extractant is 150g / L; the organic reagent in the N263 organic extractant comprises: isooctanol 15%, the balance being sulfonated kerosene, based on a total volume fraction of 100%;

[0065] The obtained loaded organic phase is washed by 5-stage countercurrent washing with 1wt% hydrochloric acid solution at 30°C, the ratio of loaded organic phase to hydrochloric acid solution being 35:1; then the washed loaded organic phase is back-extracted with pure water at 30°C, the stage number being 17, the ratio of loaded organic phase to pure water being 15:1, to obtain the cobalt chloride product liquid.

[0066] Example 3

[0067] The embodiment provides a method for preparing cobalt chloride from cobalt raw material leaching solution, and the method comprises the following steps:

[0068] (1) the pH value of the crude cobalt hydroxide slurry is adjusted to 1 by using a hydrochloric acid solution with a concentration of 12 mol / L, then hydrogen peroxide is added at 90 DEG C for reduction leaching for 2 h, the reaction is ended when the color of the leaching solution is red and the color of the filter residue is gray white, and the leaching solution is obtained; the crude cobalt hydroxide slurry is obtained by mixing crude cobalt hydroxide and water according to a solid-liquid ratio of 1:5;

[0069] (2) at 90 DEG C, calcium hydroxide solution with a mass concentration of 25wt% is added into the leaching solution obtained in step (1), and is mixed for 0.5 h, and then pressure filtration is carried out to obtain a preliminary impurity removal liquid; then P04 organic extractant is used for extracting and removing impurities from the preliminary impurity removal liquid, the temperature is 40 DEG C, the organic phase to the liquid phase ratio is 1.5:1, the extraction stage is 10 stages, and the raffinate is obtained; according to 100% of the total volume fraction, the P04 organic extractant comprises: P204 30%, and the balance is kerosene;

[0070] (3) after sodium chloride is added into the raffinate obtained in step (2) until the solution is saturated, hydrochloric acid solution with a concentration of 0.3 mol / L is added for acidification, the amount of the hydrochloric acid solution is such that the pH value of the raffinate is adjusted to-0.475; then N263 organic extractant is used for extraction, the temperature is 40 DEG C, the organic phase to the liquid phase ratio is 13:1, the extraction stage is 10 stages, and the loaded organic phase is obtained; the concentration of N263 in the N263 organic extractant is 400 g / L; according to 100% of the total volume fraction, the organic reagent in the N263 organic extractant comprises: isooctanol 30%, and the balance is sulfonated kerosene;

[0071] The loaded organic phase is washed by using hydrochloric acid solution with a mass concentration of ≤1wt% for 6 stages of countercurrent washing, the temperature is 40 DEG C, and the loaded organic phase to the hydrochloric acid solution ratio is 40:1; then the loaded organic phase after washing is stripped by using pure water, the temperature is 40 DEG C, the stage is 20 stages, the loaded organic phase to the pure water ratio is 20:1, and the cobalt chloride finished product liquid is obtained.

[0072] Embodiment 4

[0073] The embodiment provides a method for preparing cobalt chloride from cobalt raw material leaching solution, and the method comprises the following steps:

[0074] Embodiment 5

[0075] The embodiment provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, except that the second extraction organic phase is adjusted to be 15:1 compared with the leaching solution in the step (3), the rest is the same as the embodiment 1.

[0076] Embodiment 6

[0077] The embodiment provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, except that the stripping loaded organic phase is adjusted to be 12:1 compared with pure water in the step (3), the rest is the same as the embodiment 1.

[0078] Embodiment 7

[0079] The embodiment provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, except that the stripping loaded organic phase is adjusted to be 22:1 compared with pure water in the step (3), the rest is the same as the embodiment 1.

[0080] Comparative example 1

[0081] The comparative example provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, the concentration of the hydrochloric acid solution in the step (1) is replaced by a sulfuric acid solution, hydrogen peroxide is replaced by sodium sulfite, the amount of sodium sulfite is used to change the color of the leaching solution to red and the color of the filter residue to off-white, and the rest is the same as the embodiment 1.

[0082] The sulfuric acid solution used in the comparative example is not suitable for the reduction leaching system in the application, and cannot achieve effective extraction.

[0083] Comparative example 2

[0084] The comparative example provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, the P04 organic extractant is directly used in the step (2) to extract and remove impurities from the leaching solution obtained in the step (1), and the rest is the same as the embodiment 1.

[0085] Comparative example 3

[0086] The comparative example provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, the step of adding sodium chloride to the solution to saturation and adding a hydrochloric acid solution to acidify in the step (3) is omitted, and the rest is the same as the embodiment 1.

[0087] Comparative example 4

[0088] The comparative example provides a method for preparing cobalt chloride from a cobalt raw material leaching solution, which is different from the embodiment 1 in that, the N263 organic extractant in the step (3) is replaced by an equal volume of P507 extractant, and the rest is the same as the embodiment 1.

[0089] The cobalt chloride finished liquid provided by examples 1-7 and comparative examples 1-4 is subjected to component content detection by ICP, and the results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As can be seen from Table 1, the method for preparing cobalt chloride from cobalt raw material leaching liquid provided by the application can obtain cobalt chloride finished liquid with low impurity content, and solves the problem of high alkali consumption in the extraction process.

[0093] As can be seen from the comparison of example 1 with examples 4, 5, if the organic phase of the second extraction is too low compared with the liquid phase, the extraction will not be complete, and the concentration of the finished liquid will be low; if it is too high, the concentration of the finished liquid will be enriched, but the number of back-extraction stages will be small, and the back-extraction will not be complete; as can be seen from the comparison of example 1 with examples 6, 7, if the loaded organic phase of the back-extraction is too low compared with the pure water phase, the concentration of the finished liquid will be reduced; if it is too high, the concentration of the finished liquid will be enriched, but the number of back-extraction stages will be small, and the back-extraction will not be complete.

[0094] As can be seen from the comparison of example 1 with comparative example 1, the sulfuric acid solution used is not suitable for the reduction leaching system in the application, and cannot achieve extraction; as can be seen from the comparison of example 1 with comparative example 2, directly using P04 organic extractant to extract and remove impurities from the leaching liquid obtained in step (1) cannot remove iron and aluminum impurities in the leaching liquid, and the content of iron and aluminum impurities in the obtained cobalt chloride finished liquid is high; as can be seen from the comparison of example 1 with comparative example 3, not setting the step of adding sodium chloride to the solution to saturation and adding hydrochloric acid solution for acidification will cause the organic extraction rate to decrease, the concentration of the finished liquid to be low, and the extraction stage to produce a third phase; as can be seen from the comparison of example 1 with comparative example 4, using P507 extractant for extraction will significantly increase the alkali consumption and production cost, and P507 has low cobalt extraction rate without saponification.

[0095] In summary, the method for preparing cobalt chloride from cobalt raw material leaching liquid provided by the application first uses hydrochloric acid solution and hydrogen peroxide for reduction leaching, which can ensure the purity of cobalt chloride, avoid the introduction of sulfur, and reduce the amount of subsequent addition of sodium chloride as a pretreatment reagent; after using P04 organic extractant for extraction and impurity removal, N263 organic extractant is used for cobalt extraction, which has high selectivity for cobalt and basically no extraction ability for impurities such as Ni / Mg, and the organic phase does not need to be saponified, and direct extraction can be achieved; finally, through washing and back-extraction, cobalt chloride finished liquid with low impurity content is obtained, and no acid or alkali is consumed in the extraction process.

[0096] The above merely describes the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and it should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and all such changes and replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for preparing cobalt chloride from a cobalt raw material leaching solution, characterized in that, The method includes the following steps: (1) The crude cobalt hydroxide slurry was reduced and leached with hydrochloric acid solution and hydrogen peroxide to obtain a leachate; (2) The leachate obtained in step (1) is subjected to preliminary impurity removal and extraction with PO4 organic extractant to obtain raffinate; (3) The raffinate obtained in step (2) is pretreated and then extracted with N263 organic extractant. The resulting loaded organic phase is washed and back-extracted in sequence to obtain the cobalt chloride finished solution.

2. The method according to claim 1, characterized in that, The reduction leaching step in step (1) specifically includes: first, adjusting the pH value of the crude cobalt hydroxide slurry to 1-1.5 using hydrochloric acid solution, and then adding hydrogen peroxide for reduction leaching; Preferably, the temperature at which hydrogen peroxide is added is 60-90°C; Preferably, the amount of hydrogen peroxide added is such that the color of the leachate turns red and the color of the filter residue turns grayish-white; Preferably, the reduction leaching time in step (1) is 2-4 hours.

3. The method according to claim 1 or 2, characterized in that, The crude cobalt hydroxide slurry mentioned in step (1) is obtained by mixing crude cobalt hydroxide with water at a solid-liquid ratio of 1:(2-5); Preferably, the concentration of the hydrochloric acid solution in step (1) is 8-12 mol / L.

4. The method according to any one of claims 1-3, characterized in that, The preliminary impurity removal step (2) specifically includes: adding an alkali source to the leachate obtained in step (1) for mixing, and then filtering by pressure to obtain a preliminary impurity removal solution; Preferably, the alkali source includes sodium hydroxide solution and / or calcium hydroxide solution; Preferably, the concentration of the sodium hydroxide solution is 8-12 mol / L; Preferably, the mass concentration of the calcium hydroxide solution is 20-25 wt%.

5. The method according to claim 4, characterized in that, The temperature at which the alkali source is added is 60-90℃; Preferably, the mixing time is 0.5-2 hours.

6. The method according to any one of claims 1-5, characterized in that, With the total integral count as 100%, the P04 organic extractant in step (2) includes: 25-30% P2O4, with the remainder being kerosene; Preferably, the extraction and impurity removal temperature in step (2) is 20-40℃; Preferably, the ratio of organic matter to liquid material in step (2) for extraction and impurity removal is (1.2-1.5):1; Preferably, the number of extraction stages for impurity removal in step (2) is 5-10 stages.

7. The method according to any one of claims 1-6, characterized in that, The pretreatment steps in step (3) specifically include: adding sodium chloride to the raffinate obtained in step (2) until the solution is saturated, then adding hydrochloric acid solution to acidify the solution so that the pH value is <0; Preferably, the concentration of the hydrochloric acid solution is 0.23-0.3 mol / L.

8. The method according to any one of claims 1-7, characterized in that, The concentration of N263 in the N263 organic extractant in step (3) is 150-400 g / L; Preferably, with the total integral number being 100%, the organic reagents in the N263 organic extractant in step (3) include: 15-30% isooctyl alcohol, with the remainder being sulfonated kerosene; Preferably, the extraction temperature in step (3) is 20-40℃; Preferably, the ratio of organic matter extracted in step (3) to the liquid material is (8-13):1; Preferably, the extraction stage in step (3) is 7-10 stages.

9. The method according to any one of claims 1-8, characterized in that, The washing solution used in step (3) includes a hydrochloric acid solution with a mass concentration ≤1wt%; Preferably, the washing temperature in step (3) is 20-40℃; Preferably, the washing in step (3) is a 3-6 level countercurrent washing; Preferably, the ratio of the organic load to the washing liquid in step (3) is (32-40):

1.

10. The method according to any one of claims 1-9, characterized in that, The temperature for back-extraction in step (3) is 20-40℃; Preferably, the number of stages of back-extraction in step (3) is 10-20; Preferably, the back-extraction solution used in step (3) includes pure water; Preferably, the ratio of the loaded organic to the back-extraction liquid in step (3) is (14-20):1.

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