Method for preparing cobalt chloride solution at low cost through sectional extraction

Abstract

The invention discloses a method for preparing a cobalt chloride solution with low cost through sectional extraction, which comprises the following steps: carrying out calcium extraction on cobalt hydroxide leaching liquid by using a soaped first organic phase to obtain calcium extraction residual liquid; performing impurity extraction on the calcium extraction raffinate by using the soaped second organic phase to obtain impurity extraction raffinate; carrying out cobalt extraction on the impurity extraction residual liquid by adopting the soaped third organic phase to obtain cobalt extraction residual liquid and a cobalt-loaded third organic phase, and sequentially carrying out cobalt extraction section acid washing, cobalt extraction section sulfur washing and cobalt extraction section reverse extraction on the cobalt-loaded third organic phase to obtain third reverse extraction liquid; and extracting the third strip liquor by adopting a fourth organic phase after soap conversion to obtain a cobalt chloride product. According to the method for preparing the cobalt chloride solution with low cost through sectional extraction, the indexes of copper, manganese and calcium in the impurity extraction residual liquid obtained through second-stage impurity extraction can be widened to be smaller than or equal to 8 mg / L, meanwhile, the cobalt chloride solution is deeply purified through fourth-stage extraction after the third-stage cobalt extraction step, and the manufacturing cost of cobalt per ton can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrometallurgy, in particular to a method for preparing cobalt chloride solution by segmented extraction at low cost. BACKGROUND

[0002] The cobalt chloride solution is an important raw material in the fields of batteries, catalysts, pigments, etc. The relatively mature process at present is to obtain high-purity cobalt chloride solution by taking cobalt hydroxide as raw material, through acid leaching-p204 extraction impurity removal-p507 extraction. However, in order to obtain high-purity cobalt chloride solution, the Cu, Mn and Ca indexes in the P204 impurity removal section need to be controlled within 1 ppm. In actual production, in order to achieve this effect, the P204 impurity removal process often needs to maintain high saponification amount and backwashing ratio. The saponification amount is usually 2-4 times the theoretical saponification amount, and the washing rate usually needs to be more than 70%. In this way, a large amount of acid and alkali is consumed, cobalt loss is increased, a large amount of wastewater is produced, extraction equipment is required in multiple stages, the production line is unstable, etc.

[0003] In view of this, the present application is proposed. SUMMARY

[0004] The purpose of the present application is to provide a method for preparing cobalt chloride solution by segmented extraction at low cost, which can reduce reagent consumption and production cost while ensuring that the cobalt chloride solution meets the requirements.

[0005] The present application is implemented in the following manner:

[0006] In a first aspect, the present application provides a method for preparing cobalt chloride solution by segmented extraction at low cost, comprising:

[0007] In the first stage of calcium extraction, the first organic phase after saponification is used to extract calcium from the cobalt hydroxide leaching solution, to obtain calcium extraction raffinate and impurity-containing first organic phase; the volume fraction of p204 in the first organic phase is 10%-15%;

[0008] In the second stage of impurity removal, the second organic phase after saponification is used to extract impurities from the calcium extraction raffinate, to obtain impurity removal raffinate and impurity-containing second organic phase; the volume fraction of p204 in the second organic phase is 20%-25%;

[0009] In the third stage of cobalt extraction, the third organic phase after saponification is used to extract cobalt from the impurity removal raffinate, to obtain cobalt extraction raffinate and cobalt-loaded third organic phase. The cobalt-loaded third organic phase is sequentially subjected to cobalt extraction stage acid washing, cobalt extraction stage sulfur washing and cobalt extraction stage back extraction, to obtain third back extraction liquid and impurity-containing third organic phase; the volume fraction of p507 in the third organic phase is 23%-27%;

[0010] The fourth organic phase after the conversion is used to extract the third stripping liquid to obtain a raffinate and a fourth organic phase containing impurities, and the fourth organic phase after the conversion is obtained by converting the fourth organic phase after the saponification and the raffinate; the volume fraction of p204 in the fourth organic phase is 20%-25%, and the raffinate is a cobalt chloride product.

[0011] In an optional embodiment, the first organic phase containing impurities is sequentially subjected to a calcium extraction stage acid washing, a calcium extraction stage stripping, a calcium extraction stage iron stripping, and a calcium extraction stage water washing to obtain a blank first organic phase, and the blank first organic phase is used for calcium extraction after saponification.

[0012] And / or, the saponification rate of the saponified first organic phase is 20%-25%;

[0013] And / or, the saponified first organic phase is obtained by reacting the first organic phase with a first saponifying agent.

[0014] In an optional embodiment, the one-stage calcium extraction satisfies at least one of the following characteristics:

[0015] a. The first organic phase further comprises a first diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0016] b. The first saponifying agent is selected from ammonia water with a concentration of 18%-20wt%;

[0017] c. In the calcium extraction step, the O / A ratio of the extraction phase is 0.7-0.85:1, and the stage number is 5-7;

[0018] d. In the calcium extraction stage acid washing step, the O / A ratio of the acid washing phase is 12-15:1, the stage number is 2-3, and the acid washing agent used is H + sulfuric acid with a concentration of 0.2mol / L-0.4mol / L;

[0019] e. The first acid washing liquid obtained after the calcium extraction stage acid washing is mixed with the cobalt hydroxide leaching liquid to perform the one-stage calcium extraction;

[0020] f. In the calcium extraction stage stripping step, the O / A ratio of the stripping phase is 30-62:1, the stage number is 4-6, and the stripping acid used is H + hydrochloric acid with a concentration of 2.5mol / L-4.5mol / L;

[0021] g. In the calcium extraction stage iron stripping step, the O / A ratio of the iron stripping phase is 88-100:1, the stage number is 1-3, and the iron stripping acid used is H + hydrochloric acid with a concentration of 5.0mol / L-6.0mol / L;

[0022] h. The first anti-ferro liquid obtained after the anti-ferro step of the calcium extraction section is used to configure the anti-ferro acid for the anti-ferro step of the calcium extraction section;

[0023] i. In the water washing step of the calcium extraction section, the O / A ratio of the washing phase is 40-60:1, the number of stages is 1, and the washing agent used is ultrapure water;

[0024] j. The first water washing liquid obtained after the water washing step of the calcium extraction section is used to configure the anti-ferro acid for the anti-ferro step of the calcium extraction section.

[0025] In an optional embodiment, the second organic phase containing impurities is sequentially subjected to the acid washing step of the impurity extraction section, the anti-extraction step of the impurity extraction section, the anti-ferro step of the impurity extraction section, and the water washing step of the impurity extraction section to obtain a blank second organic phase, which is used for impurity extraction after saponification;

[0026] And / or, the saponification rate of the saponified second organic phase is 45%-55%;

[0027] And / or, the saponified first organic phase is obtained by reacting the first organic phase with a second saponifying agent.

[0028] In an optional embodiment, the two-stage impurity extraction satisfies at least one of the following characteristics:

[0029] a. The second organic phase further comprises a second diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0030] b. The second saponifying agent is selected from ammonia water with a concentration of 18%-20wt%;

[0031] c. In the extraction step, the O / A ratio of the extraction phase is 0.3-0.36:1, and the number of stages is 7-9;

[0032] d. In the acid washing step of the impurity extraction section, the O / A ratio of the acid washing phase is 17-22:1, the number of stages is 6-8, and the acid washing agent used is H + sulfuric acid with a concentration of 1.8mol / L-2.1mol / L;

[0033] e. The second acid washing liquid obtained after the acid washing step of the impurity extraction section is mixed with the calcium extraction residual liquid to perform two-stage impurity extraction;

[0034] f. In the anti-extraction step of the impurity extraction section, the O / A ratio of the anti-extraction phase is 17-25:1, the number of stages is 5-6, and the anti-extraction acid used is H + hydrochloric acid with a concentration of 4.0mol / L-4.5mol / L;

[0035] g. In the anti-ferro step of the impurity extraction section, the O / A ratio of the anti-ferro phase is 88-100:1, the number of stages is 1-2, and the anti-ferro acid used is H + hydrochloric acid with a concentration of 5.0mol / L-6.0mol / L;

[0036] h. The second anti-ferrous liquid is used to prepare the anti-ferrous acid for the anti-ferrous step of the impurity removal section;

[0037] i. In the water washing step of the impurity removal section, the water washing phase ratio O / A is 40-60:1, the stage number is 1, and the washing agent used is ultrapure water;

[0038] j. The second water washing liquid obtained after the water washing step of the impurity removal section is used to prepare the anti-ferrous acid for the anti-ferrous step of the impurity removal section.

[0039] k. The concentrations of Cu, Mn, and Ca in the impurity removal residual liquid are all less than 8 mg / L, and the main component of the solute is cobalt sulfate.

[0040] In an optional embodiment, the cobalt-loaded third organic phase is sequentially subjected to the acid washing step of the cobalt extraction section, the sulfur washing step of the cobalt extraction section, the anti-extraction step of the cobalt extraction section, the anti-ferrous step of the cobalt extraction section, and the water washing step of the cobalt extraction section to obtain a blank third organic phase, which is used for cobalt extraction after saponification.

[0041] And / or, the saponification rate of the saponified third organic phase is 48%-60%;

[0042] And / or, the saponified third organic phase is obtained by reacting the third organic phase with a third saponifying agent.

[0043] In an optional embodiment, the three-stage cobalt extraction satisfies at least one of the following characteristics:

[0044] a. The third organic phase further comprises a third diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0045] b. The third saponifying agent is selected from ammonia water with a concentration of 18%-20wt%;

[0046] c. In the cobalt extraction step, the extraction phase ratio O / A is 6.9-7.5:1, and the stage number is 7-8;

[0047] d. In the acid washing step of the cobalt extraction section, the acid washing phase ratio O / A is 13.8-19.2:1, the stage number is 7-10, and the acid washing agent used is H + sulfuric acid with a concentration of 1.5 mol / L-2.1 mol / L;

[0048] e. The third acid washing liquid obtained after the acid washing step of the cobalt extraction section is mixed with the impurity removal residual liquid to perform the three-stage cobalt extraction;

[0049] f. The third sulfur washing liquid obtained after the sulfur washing step of the cobalt extraction section is mixed with sulfuric acid to be used as the acid washing agent for the acid washing step of the cobalt extraction section;

[0050] g. In the back-extraction step of the cobalt extraction section, the back-extraction phase ratio O / A is 17-19:1, the stage number is 6-7, and the back-extraction acid used is H + hydrochloric acid with a concentration of 4.5 mol / L-4.8 mol / L;

[0051] h. The total concentration of Cu, Mn and Ca in the third back-extraction solution is less than 20 mg / L, and the main component of the solute is cobalt chloride;

[0052] i. In the back-ironing step of the cobalt extraction section, the back-ironing phase ratio O / A is 300-350:1, the stage number is 1-2, and the back-ironing acid used is H + hydrochloric acid with a concentration of 5.0 mol / L-6.0 mol / L;

[0053] j. The third back-ironing solution obtained after the back-ironing of the cobalt extraction section is used to prepare the back-extraction acid for back-extraction in the cobalt extraction section;

[0054] k. In the water washing step of the cobalt extraction section, the water washing phase ratio O / A is 5-15:1, the stage number is 1, and the washing agent used is ultrapure water;

[0055] l. The third water washing solution obtained after the water washing of the cobalt extraction section is used to prepare the back-ironing acid for back-ironing in the cobalt extraction section;

[0056] m. In the sulfur washing step of the cobalt extraction section, the sulfur washing phase ratio O / A is 18-18.5:1, the sulfur washing stage number is 2-3, and the washing acid is H + sulfuric acid with a concentration of 1.8 mol / L-2 mol / L.

[0057] In an optional embodiment, the fourth organic phase containing impurities is subjected to water washing of chloride ions to obtain a fourth organic phase loaded with copper, manganese, calcium and cobalt, which is returned to the second impurity extraction step;

[0058] and / or, the saponification rate of the saponified fourth organic phase is 45%-55%;

[0059] and / or, the saponified fourth organic phase is obtained by reacting the fourth organic phase with a fourth saponifying agent;

[0060] and / or, during the saponification of the fourth organic phase, the amount of saponifying agent used is 2.5-3.5 times the theoretical saponification amount.

[0061] In an optional embodiment, the fourth extraction section satisfies at least one of the following characteristics:

[0062] a. The fourth organic phase further comprises a fourth diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0063] b. The fourth saponifying agent is selected from ammonia water with a concentration of 18%-20wt%.

[0064] c. In the soap transfer step, the soap transfer phase ratio O / A is 10-12:1, and the number of stages is 7-8 stages;

[0065] d. After the soap transfer, water washing in the extraction section is also carried out, in the water washing in the extraction section, the water washing phase ratio O / A is 20-30:1, and the number of stages is 1-2 stages;

[0066] e. In the extraction step, the extraction phase ratio O / A is 0.01-0.02:1, and the number of stages is 7-9 stages;

[0067] f. In the water washing of chloride step, the water washing of chloride phase ratio O / A is 5-15:1, and the number of stages is 1 stage.

[0068] In an optional embodiment, the concentration of cobalt ions in the cobalt hydroxide leaching solution is 55-65 g / L;

[0069] And / or, the pH of the cobalt hydroxide leaching solution is 2.0-2.2;

[0070] And / or, the concentration of manganese ions in the cobalt hydroxide leaching solution is 2.5-3.5 g / L, the concentration of nickel ions is 2-2.5 g / L, the concentration of magnesium ions is 6-7.5 g / L, the concentration of iron ions is less than 0.01 g / L, the concentration of aluminum ions is less than 0.01 g / L, and the concentration of copper ions is less than 0.02 g / L.

[0071] The present application has the following beneficial effects:

[0072] In the method for preparing cobalt chloride solution at low cost by the present application, the copper, manganese and calcium indicators in the raffinate of the second extraction can be relaxed to ≤8 mg / L, and the fourth extraction step is set after the third cobalt extraction step to deeply purify the cobalt chloride solution, thereby reducing the manufacturing cost per ton of cobalt.

[0073] Further, the quality of the cobalt chloride solution prepared by the method of the present application is less affected by the concentration of copper and manganese metal ions in the cobalt hydroxide leaching solution, which is conducive to reducing the backwashing ratio during the regeneration of the second organic phase, thereby reducing the consumption of acid and alkali and wastewater output, and reducing the cost of the calcium extraction section equipment and extractant. BRIEF DESCRIPTION OF DRAWINGS

[0074] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0075] Figure 1The flow chart of Example 1 of the present application. DETAILED DESCRIPTION

[0076] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions suggested by the manufacturers are adopted. If the manufacturers of the reagents or instruments are not specified, the conventional products that can be purchased in the market are adopted.

[0077] The embodiment of the present application provides a method for preparing a cobalt chloride solution at low cost by fractional extraction, comprising the following steps:

[0078] In the first calcium extraction, the first organic phase after saponification is used to extract calcium from the cobalt hydroxide leaching solution, to obtain a calcium extraction raffinate and a first organic phase containing impurities; the volume fraction of p204 in the first organic phase is 10% to 15%, for example, 10%, 11.25%, 12.5%, 13.75%, or 15%;

[0079] In the second impurity extraction, the second organic phase after saponification is used to extract impurities from the calcium extraction raffinate, to obtain an impurity extraction raffinate and a second organic phase containing impurities; the volume fraction of p204 in the second organic phase is 20% to 25%, for example, 20%, 21.25%, 22.5%, 23.75%, or 25%;

[0080] In the third cobalt extraction, the third organic phase after saponification is used to extract cobalt from the impurity extraction raffinate, to obtain a cobalt extraction raffinate and a cobalt-loaded third organic phase; the cobalt-loaded third organic phase is sequentially subjected to cobalt extraction stage acid washing, cobalt extraction stage sulfur washing, and cobalt extraction stage back extraction, to obtain a third back-extraction solution and a third organic phase containing impurities; the volume fraction of p507 in the third organic phase is 23% to 27%, for example, 23%, 24%, 25%, 26%, or 27%;

[0081] In the fourth extraction, the fourth organic phase after saponification is used to extract impurities from the third back-extraction solution, to obtain a raffinate and a fourth organic phase containing impurities; the fourth organic phase after saponification is obtained by saponification of the fourth organic phase after saponification and the raffinate; the volume fraction of p204 in the fourth organic phase is 20% to 25%, for example, 20%, 21%, 22%, 23%, 24%, or 25%; and the raffinate is a cobalt chloride product.

[0082] In the method for preparing a cobalt chloride solution at low cost by fractional extraction, the copper, manganese, and calcium indexes in the impurity extraction raffinate of the second impurity extraction can be relaxed to ≤8 mg / L, and the fourth extraction after the third cobalt extraction step is used to deeply purify the cobalt chloride solution, so that the manufacturing cost per ton of cobalt can be reduced.

[0083] Further, the quality of the cobalt chloride solution prepared by the method of the present application is less affected by the concentration of copper and manganese metal ions in the cobalt hydroxide leaching solution, which is conducive to reducing the backwash ratio during the regeneration of the second organic phase, thereby reducing the consumption of acid and alkali and wastewater output, and reducing the cost of disposable equipment and extractant.

[0084] In optional embodiments, the first organic phase containing impurities is subjected to acid washing in the calcium extraction stage, reverse extraction in the calcium extraction stage, reverse iron extraction in the calcium extraction stage, and water washing in the calcium extraction stage in sequence to obtain a blank first organic phase, and the blank first organic phase is used for calcium extraction after saponification.

[0085] And / or, the saponification rate of the saponified first organic phase is 20% to 25%, for example, 20%, 21.25%, 22.5%, 23.75%, or 25%.

[0086] And / or, the saponified first organic phase is obtained by reacting the first organic phase with a first saponifying agent.

[0087] The first organic phase containing impurities obtained by the calcium extraction stage contains calcium, iron, aluminum, zinc, and a small amount of cobalt and manganese. The first organic phase containing calcium, iron, aluminum, zinc, and a small amount of cobalt and manganese is subjected to acid washing in the calcium extraction stage, reverse extraction in the calcium extraction stage, reverse iron extraction in the calcium extraction stage, and water washing in the calcium extraction stage in sequence. The acid washing in the calcium extraction stage mainly removes water-soluble impurities in the first organic phase. The reverse extraction in the calcium extraction stage mainly separates Ca 2+ , Zn 2+ , Mn 2+ into the aqueous phase. The reverse iron extraction in the calcium extraction stage specifically separates Fe 3+ (reduced to Fe 2+ ) and part of Al 3+ , Co 2+ . The water washing in the calcium extraction stage purifies the first organic phase, removes residual trace metals and acid mist, and regenerates the first organic phase.

[0088] In optional embodiments, the calcium extraction stage satisfies at least one of the following characteristics:

[0089] a. The first organic phase further includes a first diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0090] b. The first saponifying agent is selected from ammonia water with a concentration of 18% to 20% by weight, for example, 18%, 18.5%, 19%, 19.5%, or 20%;

[0091] c. In the calcium extraction step, the O / A ratio of the extraction phase is 0.7 to 0.85:1, for example, 0.7:1, 0.75:1, 0.8:1, or 0.85:1, and the stage number is 5 to 7, for example, 5, 6, or 7;

[0092] d. In the pickling step of the calcium extraction section, the pickling phase ratio O / A is 12-15:1, such as 12:1, 13:1, 14:1, 15:1, the stage number is 2-3, and the pickling agent used is H + sulfuric acid with a concentration of 0.2-0.4 mol / L, such as 0.2 mol / L, 0.3 mol / L, 0.4 mol / L;

[0093] e. The first pickling solution obtained after the pickling step of the calcium extraction section is mixed with the cobalt hydroxide leaching solution to perform the first calcium extraction;

[0094] f. In the stripping step of the calcium extraction section, the stripping phase ratio O / A is 30-62:1, such as 30:1, 40:1, 50:1, 62:1, the stage number is 4-6, such as 4, 5, 6, and the stripping acid used is H + hydrochloric acid with a concentration of 2.5-4.5 mol / L, such as 2.5 mol / L, 3.5 mol / L, 4.5 mol / L;

[0095] g. In the iron removal step of the calcium extraction section, the iron removal phase ratio O / A is 88-100:1, such as 88:1, 94:1, 100:1, the stage number is 1-3, such as 1, 2, 3, and the iron removal acid used is H + hydrochloric acid with a concentration of 5.0-6.0 mol / L, such as 5.0 mol / L, 5.5 mol / L, 6.0 mol / L;

[0096] h. The first iron removal solution obtained after the iron removal step of the calcium extraction section is used to prepare the stripping acid for the stripping step of the calcium extraction section;

[0097] i. In the water washing step of the calcium extraction section, the water washing phase ratio O / A is 40-60:1, such as 40:1, 50:1, 60:1, and the washing agent used is ultrapure water;

[0098] j. The first water washing solution obtained after the water washing step of the calcium extraction section is used to prepare the iron removal acid for the iron removal step of the calcium extraction section.

[0099] Reasonable selection of the parameters of the first calcium extraction process is conducive to reducing the use amount of acid and alkali and the production amount of wastewater while maintaining the quality of cobalt chloride products, and is conducive to reducing costs.

[0100] In an optional embodiment, the impurity-containing second organic phase is sequentially subjected to the pickling, stripping, iron removal, and water washing steps of the impurity extraction section to obtain a blank second organic phase, which is subjected to saponification and then used for impurity extraction;

[0101] And / or, the saponification rate of the saponified second organic phase is 45%-55%, such as 45%, 48%, 50%, 52%, 55%;

[0102] And / or, the first organic phase after soaping is obtained by reacting the first organic phase with the second saponifying agent.

[0103] Through a two-stage extraction process, a second organic phase containing impurities was obtained, loaded with calcium, copper, manganese, and trace amounts of iron, aluminum, zinc, and cobalt. This second organic phase was then subjected to a series of processes: acid washing in the extraction stage, back-extraction in the extraction stage, iron removal in the extraction stage, and water washing in the extraction stage. The acid washing in the extraction stage primarily removed the calcium from the second organic phase. 2+ Extraction of impurities mainly separates Cu 2+ Mn 2+ Zn 2+ Co 2+ In the aqueous phase, the iron-containing fraction is used for targeted separation of Fe. 3+ (reduced to Fe) 2+ ) and some Al 3+ The second organic phase is purified by water washing in the extraction stage to remove residual trace metals and acid mist, thereby regenerating the second organic phase.

[0104] In an optional implementation, the two-stage extraction and purification process satisfies at least one of the following characteristics:

[0105] a. The second organic phase further includes a second diluent, the second diluent being selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0106] b. The second saponifying agent is selected from ammonia water with a concentration of 18% to 20 wt%, for example, 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, or 20 wt%;

[0107] c. In the extraction step, the extraction ratio O / A is 0.3 to 0.36:1, for example 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt%, and the number of stages is 7 to 9, for example 7 stages, 8 stages, 9 stages;

[0108] d. In the pickling step of the extraction section, the pickling ratio O / A is 17–22:1, for example 17:1, 19:1, 21:1, 22:1; the number of pickling stages is 6–8, for example 6, 7, 8; the pickling agent used is H + Sulfuric acid with a concentration of 1.8 mol / L to 2.1 mol / L, such as 1.8 mol / L, 2.0 mol / L, and 2.1 mol / L;

[0109] e. After acid washing in the extraction stage, a second acid washing solution is obtained. The second acid washing solution is mixed with the calcium extraction residue for a two-stage extraction process.

[0110] f. In the stripping step of the second extraction and impurity removal section, the O / A ratio of the stripping phase is 17-25:1, such as 17:1, 20:1, 23:1, 25:1; the number of stages is 5-6, and the stripping acid used is H + hydrochloric acid with a concentration of 4.0-4.5 mol / L, such as 4.0 mol / L, 4.3 mol / L, 4.5 mol / L;

[0111] g. In the iron removal step of the second extraction and impurity removal section, the O / A ratio of the iron removal phase is 88-100:1, such as 88:1, 94:1, 100:1; the number of stages is 1-2, and the iron removal acid used is H + hydrochloric acid with a concentration of 5.0-6.0 mol / L, such as 5.0 mol / L, 5.5 mol / L, 6.0 mol / L;

[0112] h. The second iron removal solution obtained after the iron removal step of the second extraction and impurity removal section is used to prepare the stripping acid for the stripping step of the second extraction and impurity removal section.

[0113] i. In the water washing step of the second extraction and impurity removal section, the O / A ratio of the water washing phase is 40-60:1, such as 40:1, 50:1, 60:1; the number of stages is 1, and the washing agent used is ultrapure water.

[0114] j. The second water washing solution obtained after the water washing step of the second extraction and impurity removal section is used to prepare the iron removal acid for the iron removal step of the second extraction and impurity removal section.

[0115] k. The concentrations of Cu, Mn, and Ca in the second extraction and impurity removal section are all less than 8 mg / L, and the main component of the solute is cobalt sulfate.

[0116] The present application sets up four extraction sections, so that in the second extraction and impurity removal section, the concentrations of Cu, Mn, and Ca in the second extraction and impurity removal section are relatively loose, and without the need to maintain a high saponification amount and backwashing ratio, the concentrations of Cu, Mn, and Ca in the second extraction and impurity removal section can be all less than 8 mg / L, which is conducive to reducing the consumption of acid and alkali, cobalt loss, and wastewater output.

[0117] Reasonable selection of the parameters of the second extraction and impurity removal section is conducive to maintaining the quality of cobalt chloride products while reducing the amount of acid and alkali used and the amount of wastewater produced, and is conducive to reducing costs.

[0118] In optional embodiments, the cobalt-loaded third organic phase is sequentially subjected to an acid washing step, a sulfur washing step, a stripping step, an iron removal step, and a water washing step, and the blank third organic phase obtained after the water washing step is used for saponification and cobalt extraction.

[0119] And / or, the saponification rate of the saponified third organic phase is 48%-60%.

[0120] And / or, the saponified third organic phase is obtained by reacting the third organic phase with a third saponifying agent.

[0121] The cobalt is extracted by three-stage cobalt extraction, and the cobalt-loaded third organic phase mainly loaded with cobalt and a small amount of nickel and magnesium is obtained. The cobalt-loaded third organic phase is sequentially subjected to cobalt extraction stage acid washing, cobalt extraction stage sulfur washing, cobalt extraction stage back extraction, cobalt extraction stage back iron, and cobalt extraction stage water washing to obtain a blank third organic phase. In the cobalt extraction stage acid washing, Ca 2+ and part of Mg 2+ are mainly washed out in the third organic phase. 2- , NH4 + , and extremely small amount of metal ions are mainly washed out in the third organic phase. 2+ , Ni 2+ and a small amount of Mg 2+ are mainly separated into the aqueous phase in the cobalt extraction stage back extraction. 2+ The cobalt extraction stage back iron is used to specifically separate the small amount of Mg + remaining in the cobalt extraction stage back extraction.

[0122] In optional embodiments, the three-stage cobalt extraction satisfies at least one of the following characteristics:

[0123] a. The third organic phase further comprises a third diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane.

[0124] b. The third saponifier is selected from ammonia water with a concentration of 18% to 20% by weight, such as 18%, 18.5%, 19%, 19.5%, or 20%.

[0125] c. In the cobalt extraction step, the O / A ratio of the extraction phase is 6.9 to 7.5:1, such as 6.9:1, 7.1:1, 7.3:1, or 7.5:1; and the number of stages is 7 to 8.

[0126] d. In the cobalt extraction stage acid washing step, the O / A ratio of the acid washing phase is 13.8 to 19.2:1, such as 13.8:1, 15:1, 17:1, or 19.2:1; the number of stages is 7 to 10, such as 7, 8, 9, or 10; and the acid used is H + 2SO4 with a concentration of 1.5 mol / L to 2.1 mol / L, such as 1.5 mol / L, 1.8 mol / L, or 2.1 mol / L.

[0127] e. The third acid washing liquid obtained after the cobalt extraction stage acid washing is mixed with the cobalt extraction raffinate to perform the three-stage cobalt extraction.

[0128] f. The third sulfur washing liquid obtained after the cobalt extraction stage sulfur washing is mixed with sulfuric acid to be used for acid washing in the cobalt extraction stage acid washing.

[0129] g. In the back-extraction step of the cobalt extraction section, the back-extraction phase ratio O / A is 17-19:1, such as 17:1, 18:1, 19:1; the stage number is 6-7 stages, and the back-extraction acid used is H + hydrochloric acid with a concentration of 4.5 mol / L-4.8 mol / L, such as 4.5 mol / L, 4.7 mol / L, 4.8 mol / L;

[0130] h. The total concentration of Cu, Mn, and Ca in the third back-extraction solution is less than 20 mg / L, and the main component of the solute is cobalt chloride;

[0131] i. In the back-ironing step of the cobalt extraction section, the back-ironing phase ratio O / A is 300-350:1, such as 300:1, 325:1, 350:1; the stage number is 1-2 stages, and the back-ironing acid used is H + hydrochloric acid with a concentration of 5.0 mol / L-6.0 mol / L, such as 5.0 mol / L, 5.5 mol / L, 6.0 mol / L;

[0132] j. The third back-ironing solution obtained after the back-ironing of the cobalt extraction section is used to prepare the back-extraction acid for the back-extraction of the cobalt extraction section;

[0133] k. In the water washing step of the cobalt extraction section, the water washing phase ratio O / A is 5-15:1, such as 5:1, 10:1, 15:1; the stage number is 1 stage, and the washing agent used is ultrapure water;

[0134] l. The third water washing solution obtained after the water washing of the cobalt extraction section is used to prepare the back-ironing acid for the back-ironing of the cobalt extraction section;

[0135] m. In the sulfur washing step of the cobalt extraction section, the sulfur washing phase ratio O / A is 18-18.5:1, such as 18:1, 18.3:1, 18.5:1, the sulfur washing stage number is 2-3 stages, and the washing acid is H + sulfuric acid with a concentration of 1.8 mol / L-2 mol / L, such as 1.8 mol / L, 1.9 mol / L, 2.0 mol / L.

[0136] Reasonable selection of the parameters of the three-stage cobalt extraction process is conducive to reducing the amount of acid and base used and the amount of wastewater produced while maintaining the quality of cobalt chloride products, and is conducive to reducing costs.

[0137] In an optional embodiment, the fourth organic phase containing impurities is washed with chloride ions to obtain a fourth organic phase loaded with copper, manganese, calcium, and cobalt, and the fourth organic phase loaded with copper, manganese, calcium, and cobalt is returned to the second impurity extraction step;

[0138] And / or, the saponification rate of the saponified fourth organic phase is 45%-55%, such as 45%, 47%, 49%, 51%, 53%, 55%;

[0139] And / or, the fourth organic phase after saponification is obtained by reacting the fourth organic phase with a fourth saponification agent;

[0140] And / or, in the saponification process of the fourth organic phase, the saponification amount of the reagent is 2.5-3.5 times the theoretical saponification amount, for example, 2.5 times, 2.7 times, 2.9 times, 3.1 times, 3.3 times, 3.5 times.

[0141] Through four-stage extraction, the fourth organic phase containing impurities mainly loaded with calcium, copper, manganese, and chlorine is obtained. The fourth organic phase containing impurities is washed with water to obtain a fourth organic phase loaded with copper, manganese, calcium, and cobalt. It should be noted that the fourth organic phase after saponification needs to be washed with water before extraction to remove ammonium in it.

[0142] In optional embodiments, the four-stage extraction satisfies at least one of the following characteristics:

[0143] a. The fourth organic phase further comprises a fourth diluent selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane;

[0144] b. The fourth saponification agent is selected from ammonia water with a concentration of 18-20 wt%, for example, 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, 20 wt%;

[0145] c. In the saponification step, the saponification phase ratio O / A is 10-12:1, for example, 10:1, 10.5:1, 11:1, 11.5:1, 12:1; the stage number is 7-8;

[0146] d. The fourth organic phase after saponification is further washed in the extraction stage. In the extraction stage washing step, the water washing phase ratio O / A is 20-30:1, for example, 20:1, 22:1, 24:1, 26:1, 28:1, 30:1; the water washing stage number is 1-2;

[0147] e. In the extraction step, the extraction phase ratio O / A is 0.01-0.02:1, for example, 0.01:1, 0.012:1, 0.014:1, 0.016:1, 0.018:1, 0.02:1; the stage number is 7-9;

[0148] f. In the water washing step, the water washing phase ratio O / A is 5-15:1, for example, 5:1, 7:1, 9:1, 11:1, 13:1, 15:1; the stage number is 1.

[0149] Reasonable selection of parameters in the four-stage extraction process is conducive to maintaining the quality of cobalt chloride products while reducing the amount of acid and base used and the amount of wastewater produced, which is conducive to reducing costs.

[0150] In an alternative embodiment, the cobalt ion concentration in the cobalt hydroxide leaching solution is 55 g / L to 65 g / L, for example 55 g / L, 58 g / L, 60 g / L, 63 g / L, 65 g / L;

[0151] And / or, the pH of the cobalt hydroxide leaching solution is 2.0 to 2.2, for example 2.0, 2.1, 2.2;

[0152] And / or, the manganese ion concentration in the cobalt hydroxide leaching solution is 2.5 g / L to 3.5 g / L, the nickel ion concentration is 2 g / L to 2.5 g / L, the magnesium ion concentration is 6 g / L to 7.5 g / L, the iron ion concentration is less than 0.01 g / L, the aluminum ion concentration is less than 0.01 g / L, and the copper ion concentration is less than 0.02 g / L.

[0153] The features and performance of the present application are further described in detail below in conjunction with the examples.

[0154] Example 1

[0155] This example provides a method for preparing a cobalt chloride solution at low cost by fractional extraction, and the specific process is shown in Figure 1 The composition of the cobalt hydroxide leaching solution is shown in Table 1:

[0156] Table 1 Composition and content of cobalt hydroxide leaching solution g / L

[0157] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]]> Cu 2+ ]]> Zn 2+ ]] Ca 2+ ]]> Mg 2+ ]]> pH 60.42 2.98 2.39 0.005 0.005 0.01 0.20 0.67 6.76 2.1

[0158] Specifically includes the following steps:

[0159] (1) The first organic phase with a saponification rate of 25% (i.e. the volume fraction of P204 extractant is 15%, and the diluent is sulfonated kerosene) is used to extract calcium from the cobalt hydroxide leaching solution shown in Table 1 to obtain a calcium extraction raffinate and a first organic phase containing impurities of calcium, manganese, zinc, iron, aluminum and cobalt, the phase ratio of extraction is O / A = 0.81:1, and the extraction stage is 6 stages;

[0160] The first organic phase containing impurities is sequentially subjected to calcium extraction section acid washing, calcium extraction section stripping, calcium extraction section iron stripping, and calcium extraction section water washing to obtain a blank first organic phase, which is used for calcium extraction after saponification; wherein the phase ratio of calcium extraction section acid washing is O / A = 13.2:1, the washing stage is 3 stages, and the washing acid is H + 0.3 mol / L sulfuric acid; the phase ratio of calcium extraction section stripping is O / A = 61:1, the stage is 6 stages, and the stripping acid used is H +6 mol / L hydrochloric acid, the O / A ratio of the water washing stage was 45:1, and the stage number was 1, to obtain a blank first organic phase and a zinc-aluminum-iron chloride solution.

[0161] Table 2 Composition and content of the calcium extraction raffinate g / L

[0162] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]] Al 3+ ]]> Cu 2+ ]]> Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]]> pH 56.55 2.247 2.252 0.001 0.001 0.0094 0.010 0.116 6.37 2.36

[0163] (2) The second organic phase with a saponification rate of 50% (i.e., the volume fraction of P204 extractant was 20%, and the diluent was sulfonated kerosene) was used to extract the calcium extraction raffinate (Ca≤150 mg / L), the O / A ratio of the extraction was 0.3:1, and the stage number was 9, to obtain a raffinate and a second organic phase containing impurities;

[0164] The second organic phase containing impurities was sequentially subjected to an acid washing stage, a stripping stage, an iron stripping stage, and a water washing stage, to obtain a blank second organic phase, which was used for impurity extraction after saponification; wherein, the O / A ratio of the acid washing stage was 17.77:1, the washing stage number was 7, the washing acid was H + 2 mol / L sulfuric acid, the O / A ratio of the stripping stage was 17.13:1, the stripping stage number was 6, and the stripping acid was H + 4.5 mol / L hydrochloric acid, the O / A ratio of the iron stripping stage was 88.5:1, the iron stripping stage number was 2, and the iron stripping acid was H + 5.2 mol / L hydrochloric acid, the O / A ratio of the water washing stage was 46.5:1, and the stage number was 1, to obtain a raffinate (the concentrations of Cu, Mn, and Ca were all less than 8 mg / L) and a calcium-manganese chloride solution.

[0165] Table 3 Composition and content of the impurity extraction raffinate g / L

[0166] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]]> Cu 2+ ]]> Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]]> pH 55.407 0.008 2.028 0.0008 0.0006 0.004 0.010 0.006 5.737 2.94

[0167] (3) The third organic phase with a saponification rate of 50% (i.e., the volume fraction of P507 extractant was 25%, and the diluent was sulfonated kerosene) was used to extract the impurity extraction raffinate (Cu, Mn, Ca≤8 mg / L), the O / A ratio of the extraction was 7.24:1, and the stage number was 8, to obtain a cobalt extraction raffinate and a cobalt-loaded third organic phase, and the cobalt-loaded third organic phase was sequentially subjected to an acid washing stage, a sulfur washing stage, and a stripping stage, to obtain a third stripping solution and a third organic phase containing impurities;

[0168] The cobalt-loaded third organic phase was sequentially subjected to an acid washing stage, a sulfur washing stage, a stripping stage, an iron stripping stage, and a water washing stage, to obtain a blank third organic phase, which was used for cobalt extraction after saponification; wherein, the O / A ratio of the acid washing stage was 18:1, the washing stage number was 10, the O / A ratio of the sulfur washing stage was 18:1, the sulfur washing stage number was 3, and the washing acid was H + 4 mol / L sulfuric acid and sulfuric acid washing water+ 2 mol / L acid; back-extraction ratio O / A = 17.37:1, 6 back-extraction stages, back-extraction acid is H. + With 4.5 mol / L hydrochloric acid, the antiferric ratio in the cobalt extraction section is O / A = 315:1, the antiferric order is 2, and the antiferric acid in the cobalt extraction section is H. + 6.0 mol / L hydrochloric acid, with a cobalt extraction section water washing ratio of O / A = 14:1, and a water washing stage of 1; yielded a cobalt chloride solution containing impurities, namely the third back-extraction solution (Cu, Mn, Ca ≤ 20 mg / L) and a magnesium ammonium sulfate solution.

[0169] Table 4. Components and content (g / L) of the third back-extraction solution

[0170] Co 2+ ]] Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]]> Cu 2+ ]] Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]]> pH 130.32 0.019 0.0004 0.0006 0.0004 0.012 0.0007 0.015 0.0009 2.23

[0171] (4) The fourth organic phase (i.e., 25% P204 extractant volume fraction, sulfonated kerosene as diluent) with a saponification rate of 50% (three times the theoretical amount) is subjected to saponification with a high-purity cobalt chloride solution, i.e., the raffinate. The saponification ratio is 11.76:1, and the saponification stage is 7. After saponification, the organic phase is washed with water to remove ammonium ions, i.e., the extraction section is washed with water. The washing ratio is O / A = 30:1, and the stage is 2. After washing, the saponified organic phase is then subjected to a cobalt chloride solution containing impurities, i.e., the third back-extraction solution (Cu, Mn, Ca ≤ 20 mg / L). Extraction was performed using a ratio of g / L, with an extraction ratio of O / A = 0.014:1 (this ratio refers to the feed flow rate ratio, and organic reflux is required in this stage). The number of stages was 7. After extraction, the loaded organic impurities were washed with water to remove chloride ions, with a water-wash chloride ion ratio of 10:1. This was done in one stage to obtain a high-purity cobalt chloride solution and the loaded organic impurities. The fourth organic loading of copper, manganese, calcium, and cobalt was returned to the fifth stage of the extraction process in step 2. After returning, the cobalt in the fourth organic loading continued to exchange ions with the impurities in the calcium extraction residue from step 2. The high-purity cobalt chloride solution was then sold.

[0172] Table 5. Components and content (g / L) of high-purity cobalt chloride solution

[0173] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]]> Cu 2+ ]] Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]] pH 130.10 0.001 0.0004 0.0005 0.0003 0.0006 0.0005 0.0007 0.0008 2.31

[0174] Example 2:

[0175] This embodiment provides a method for preparing cobalt chloride solution at low cost through segmented extraction. The specific process is as follows: Figure 1 As shown in Table 1, the composition of the cobalt hydroxide leaching solution includes the following steps:

[0176] (1) The first organic phase with a saponification rate of 23% (i.e., P204 extractant volume fraction of 13%, and sulfonated kerosene as diluent) was used to extract calcium from the cobalt hydroxide leachate to obtain calcium extraction residue and the first organic phase containing impurities loaded with calcium, manganese, zinc, iron, aluminum and cobalt. The extraction ratio O / A = 0.83:1 and the number of extraction stages was 6.

[0177] The first organic phase containing impurities is sequentially subjected to acid washing in the calcium extraction stage, reverse extraction in the calcium extraction stage, reverse iron extraction in the calcium extraction stage, and water washing in the calcium extraction stage to obtain a blank first organic phase, which is used for calcium extraction after saponification; wherein the acid washing in the calcium extraction stage has an O / A ratio of 14.2:1, three washing stages, and H + 0.35 mol / L sulfuric acid; the reverse extraction in the calcium extraction stage has an O / A ratio of 61:1, six extraction stages, and H + 6 mol / L hydrochloric acid, and the water washing in the calcium extraction stage has an O / A ratio of 43.3:1 to obtain a blank first organic phase and a zinc aluminum iron chloride solution.

[0178] Table 6 Composition and content g / L of the calcium extraction residue

[0179] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]]> Cu 2+ ]]> Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]]> pH 56.47 2.348 2.252 0.0008 0.0009 0.0094 0.010 0.143 6.37 2.36

[0180] (2) The second organic phase with a saponification rate of 50% (i.e., the volume fraction of P204 extraction agent is 25%, and the diluent is sulfonated kerosene) is used for impurity extraction on the calcium extraction residue (Ca≤150 mg / L), the extraction phase ratio is O / A=0.36:1, the extraction stage is 9, and the impurity extraction residue and the second organic phase containing impurities are obtained.

[0181] The second organic phase containing impurities is sequentially subjected to acid washing in the calcium extraction stage, reverse extraction in the calcium extraction stage, reverse iron extraction in the calcium extraction stage, and water washing in the calcium extraction stage to obtain a blank first organic phase, which is used for calcium extraction after saponification; wherein the acid washing in the calcium extraction stage has an O / A ratio of 14.2:1, three washing stages, and H + 2 mol / L sulfuric acid; the reverse extraction in the calcium extraction stage has an O / A ratio of 17.13:1, six extraction stages, and H + 4.5 mol / L hydrochloric acid, the reverse iron extraction in the calcium extraction stage has an O / A ratio of 89.9:1, two iron extraction stages, and H + 5.8 mol / L hydrochloric acid, the water washing in the calcium extraction stage has an O / A ratio of 42:1, and one stage, to obtain a impurity extraction residue (Cu, Mn, Ca≤8 mg / L) and a calcium manganese chloride solution.

[0182] Table 7 Composition and content g / L of the impurity extraction residue

[0183] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]] Al 3+ ]] Cu 2+ ]]> Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]]> pH 54.38 0.008 2.028 0.0006 0.0007 0.005 0.010 0.007 5.737 2.89

[0184] (3) the third organic phase with a saponification rate of 55% (i.e. P507 extractant volume fraction 25%, diluent sulfonated kerosene) is used to extract the raffinate (Cu, Mn, Ca≤8 mg / L) to obtain a cobalt extraction raffinate and a cobalt-loaded third organic phase, the cobalt-loaded third organic phase is sequentially subjected to cobalt extraction section acid washing, cobalt extraction section sulfur washing and cobalt extraction section stripping to obtain a third stripping solution and a third organic phase containing impurities;

[0185] The cobalt-loaded third organic phase is sequentially subjected to cobalt extraction section acid washing, cobalt extraction section sulfur washing, cobalt extraction section stripping, cobalt extraction section iron stripping and cobalt extraction section water washing to obtain a blank third organic phase, which is used for cobalt extraction after saponification; wherein the cobalt extraction section acid washing has an O / A ratio of 18.32:1, and the washing has 10 stages; the cobalt extraction section sulfur washing has an O / A ratio of 18.32:1, and the sulfur washing has 2 stages; the washing acid is H + 3.6 mol / L sulfuric acid and sulfuric acid washing water to prepare H + 1.8 mol / L acid; the stripping has an O / A ratio of 17.37:1, and the stripping has 6 stages; the stripping acid is H + 4.5 mol / L hydrochloric acid; the cobalt extraction section iron stripping has an O / A ratio of 302:1, and the iron stripping has 2 stages; the cobalt extraction section iron stripping acid is H + 5.79 mol / L hydrochloric acid; the cobalt extraction section water washing has an O / A ratio of 15:1, and the water washing has 1 stage to obtain a cobalt chloride solution containing impurities, i.e. a third stripping solution (Cu, Mn, Ca≤20 mg / L) and an ammonium sulfate magnesium solution.

[0186] Table 8 Components and contents g / L of the cobalt chloride solution containing impurities, i.e. the third stripping solution

[0187] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]]> Cu 2+ ]] Zn 2+ ]]> Ca 2+ ]] Mg 2+ ]]> pH 130.32 0.019 0.0004 0.0003 0.0004 0.015 0.0007 0.018 0.0008 2.18

[0188] (4) the fourth organic phase with a saponification rate of 45% (saponification amount is 3 times the theoretical amount) (i.e. P204 extractant volume fraction 25%, diluent sulfonated kerosene) is used to convert the cobalt chloride solution containing impurities, i.e. the third stripping solution (Cu, Mn, Ca≤20 mg / L) to obtain a high-purity cobalt chloride solution and an organic phase loaded with impurities, the organic phase after conversion is subjected to water washing of ammonium ions, i.e. extraction section water washing, the water washing has an O / A ratio of 30:1, and the water washing has 2 stages, the organic phase after water washing is used to extract the cobalt chloride solution containing impurities, i.e. the third stripping solution (Cu, Mn, Ca≤20 mg / L) to obtain an organic phase loaded with impurities, the organic phase loaded with impurities is subjected to water washing of chloride ions, the water washing has an O / A ratio of 10:1, and the water washing has 1 stage to obtain the high-purity cobalt chloride solution and the organic phase loaded with impurities, the organic phase loaded with cobalt, manganese, calcium and cobalt after water washing is returned to the extraction of 5 stages in step 2, the cobalt in the loaded organic phase continues to exchange with the impurity ions in the calcium extraction raffinate in step 2, and the high-purity cobalt chloride solution is sold.

[0189] Table 9 Composition and content of high-purity cobalt chloride solution g / L

[0190] Co 2+ ]] Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]] Cu 2+ ]] Zn 2+ ]]> Ca 2+ ]]> Mg 2+ ]]> pH 130.10 0.0004 0.0006 0.0005 0.0003 0.0007 0.0004 0.0006 0.0007 2.31

[0191] Example 3:

[0192] This embodiment provides a method for preparing cobalt chloride solution at low cost by staged extraction, and the specific process is shown in Figure 1 The composition of the cobalt hydroxide leaching solution is shown in Table 1, and the method comprises the following steps:

[0193] (1) The first organic phase with a saponification rate of 23% (i.e., the volume fraction of P204 extractant is 13%, and the diluent is sulfonated kerosene) is used to extract calcium from the cobalt hydroxide leaching solution, to obtain a calcium extraction raffinate and a first organic phase loaded with calcium, manganese, zinc, iron, aluminum and cobalt; the extraction phase ratio O / A is 0.83:1, and the extraction stage number is 6;

[0194] The first organic phase loaded with impurities is sequentially subjected to calcium extraction section acid washing, calcium extraction section stripping, calcium extraction section iron stripping, and calcium extraction section water washing to obtain a blank first organic phase, which is used for calcium extraction after saponification; wherein, the acid washing phase ratio O / A of the calcium extraction section acid washing is 14.2:1, the washing stage number is 3, and the washing acid is H + 0.35 mol / L sulfuric acid; the stripping phase ratio O / A of the calcium extraction section stripping is 61:1, the stripping stage number is 6, the stripping acid is H + 6 mol / L hydrochloric acid, and the water washing phase ratio O / A of the calcium extraction section water washing is 43.3:1, to obtain a blank first organic phase and a zinc aluminum iron chloride solution.

[0195] Table 6 Composition and content of calcium extraction raffinate g / L

[0196] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]] Al 3+ ]]> Cu 2+ ]] Zn 2+ ]]> Ca 2+ ]] Mg 2+ ]]> pH 56.47 2.348 2.252 0.0007 0.0009 0.0094 0.010 0.143 6.37 2.36

[0197] (2) The second organic phase with a saponification rate of 50% (i.e., the volume fraction of P204 extractant is 20%, and the diluent is sulfonated kerosene) is used to extract impurities from the calcium extraction raffinate (Ca≤150 mg / L), the extraction phase ratio O / A is 0.36:1, the extraction stage number is 6, and a calcium extraction raffinate and a second organic phase loaded with impurities are obtained;

[0198] The second organic phase loaded with impurities is sequentially subjected to impurity extraction section acid washing, impurity extraction section stripping, impurity extraction section iron stripping, and impurity extraction section water washing to obtain a blank second organic phase, which is used for impurity extraction after saponification; wherein, the acid washing phase ratio O / A of the impurity extraction section acid washing is 18.2:1, the washing stage number is 7, and the washing acid is H + 2 mol / L sulfuric acid; the stripping phase ratio O / A of the impurity extraction section stripping is 17.13:1, the stripping stage number is 6, and the stripping acid is H+ 4.5mol / L of hydrochloric acid, the ratio of the extraction section to the impurity removal section O / A = 89.9:1, the anti-ferrous stage is 2, and the anti-ferrous acid is H + 5.8mol / L of hydrochloric acid, the ratio of the extraction section to the impurity removal section O / A = 42:1, the impurity removal raffinate and the calcium manganese chloride solution are obtained.

[0199] Table 7 Composition and content g / L of the impurity removal raffinate

[0200] Co 2+ ]]> Mn 2+ ]]> Ni 2+ ]]> Fe 2+ ]] Al 3+ ]]> Cu 2+ ]]> Zn 2+ ]]> Ca 2+ ]] Mg 2+ ]]> pH 54.38 0.025 2.028 0.001 0.0006 0.007 0.010 0.019 5.737 2.74

[0201] (3) The third organic phase with a saponification rate of 55% (i.e. the volume fraction of P507 extractant is 25%, and the diluent is sulfonated kerosene) is used to extract the impurity removal raffinate (Cu, Mn, Ca ≤ 8mg / L), the ratio of the extraction section to the impurity removal section O / A = 6.98:1, the extraction stage is 8, the cobalt extraction raffinate and the cobalt-loaded third organic phase are obtained, and the cobalt-loaded third organic phase is sequentially subjected to the cobalt extraction section acid washing, the cobalt extraction section sulfur washing, and the cobalt extraction section stripping to obtain the third stripping solution and the impure third organic phase;

[0202] The cobalt-loaded third organic phase is sequentially subjected to the cobalt extraction section acid washing, the cobalt extraction section sulfur washing, the cobalt extraction section stripping, the cobalt extraction section anti-ferrous, and the cobalt extraction section water washing to obtain the blank third organic phase, which is used for cobalt extraction after saponification; wherein the ratio of the cobalt extraction section acid washing to the impurity removal section O / A = 18.32:1, the washing stage is 10, the ratio of the cobalt extraction section sulfur washing to the impurity removal section O / A = 18.32:1, the sulfur washing stage is 2, and the washing acid is H + 3.6mol / L of sulfuric acid and H + 1.8mol / L; the ratio of the stripping section to the impurity removal section O / A = 17.37:1, the stripping stage is 6, and the stripping acid is H + 4.5mol / L of hydrochloric acid, the ratio of the cobalt extraction section anti-ferrous to the impurity removal section O / A = 302:1, the anti-ferrous stage is 2, and the cobalt extraction section anti-ferrous acid is H + 5.79mol / L of hydrochloric acid, the ratio of the cobalt extraction section water washing to the impurity removal section O / A = 15:1, the water washing stage is 1, and the impure cobalt chloride solution, i.e. the third stripping solution, and the ammonium sulfate magnesium solution are obtained.

[0203] Table 8 Composition and content g / L of the impure cobalt chloride solution, i.e. the third stripping solution

[0204] Co 2+ ]] Mn 2+ ]] Ni 2+ ]]> Fe 2+ ]] Al 3+ ]] Cu 2+ ]] Zn 2+ ]] Ca 2+ ]] Mg 2+ ]] pH 130.32 0.058 0.0008 0.0007 0.0009 0.019 0.0004 0.046 0.0008 2.18

[0205] (4) the fourth organic phase (i.e. P204 extractant volume fraction 25%, diluent sulfonated kerosene) with a saponification rate of 45% (saponification amount 3 times the theoretical amount) is subjected to a saponification conversion with a high-purity cobalt chloride solution, the saponification conversion ratio is 11.76:1, the saponification conversion stages are 7, the saponification conversion organic phase is subjected to an ammonium ion water washing, i.e. extraction section water washing, the water washing phase ratio O / A=30:1, the water washing stages are 2, the saponification conversion organic phase after water washing is subjected to an extraction with a mixed cobalt chloride solution, i.e. the third stripping solution (Cu, Mn, Ca≤20 mg / L), the extraction phase ratio O / A=0.014:1 (the phase ratio is a feed flow ratio, organic reflux needs to be carried out in this stage), the extraction stages are 7, the impurity-loaded organic after extraction is subjected to a chloride ion water washing, the water washing phase ratio is 10:1, the water washing stages are 1, a high-purity cobalt chloride solution and an impurity-loaded organic are obtained, the copper, manganese, calcium and cobalt-loaded organic after water washing returns to the extraction in step 2 for 5 stages, the cobalt in the loaded organic after returning continues to exchange with the impurity ions in the calcium stripping solution in step 2, at this time, the cobalt chloride in the stripping solution contains impurities and is unqualified.

[0206] Table 9 high-purity cobalt chloride solution composition and content g / L

[0207] Co 2+ ]] Mn 2+ ]] Ni 2+ ]]> Fe 2+ ]]> Al 3+ ]] Cu 2+ ]] Zn 2+ ]] Ca 2+ ]] Mg 2+ ]]> pH 130.10 0.005 0.0004 0.0007 0.0008 0.002 0.0006 0.006 0.0004 2.31

[0208] Comparative example

[0209] The embodiment provides a segmented extraction low-cost cobalt chloride solution preparation method, the components of a cobalt hydroxide leaching solution are shown in Table 1, and the method specifically comprises the following steps:

[0210] (1) the first organic phase (i.e. P204 extractant volume fraction 15%, diluent sulfonated kerosene) with a saponification rate of 25% is used for calcium extraction on the cobalt hydroxide leaching solution to obtain a calcium extraction residual solution and an impurity-loaded first organic phase loaded with calcium, manganese, zinc, iron, aluminum and cobalt, the extraction phase ratio O / A=0.81:1, and the extraction stages are 7;

[0211] The impurity-loaded first organic phase is subjected to calcium extraction section acid washing, calcium extraction section stripping, calcium extraction section iron stripping and calcium extraction section water washing in sequence to obtain a blank first organic phase, and the blank first organic phase is subjected to saponification and used for calcium extraction; wherein the calcium extraction section acid washing washing phase ratio O / A=13.7:1, the washing stages are 3, the washing acid is 0.3 mol / L sulfuric acid, the calcium extraction section stripping phase ratio O / A=61:1, the stages are 6, the acid is 4.5 mol / L hydrochloric acid, the calcium extraction residual solution (Ca≤70 mg / L) and a calcium zinc chloride solution are obtained, the calcium extraction section iron stripping phase ratio O / A=88:1, the stages are 3, the acid used in the calcium extraction section iron stripping is 6 mol / L hydrochloric acid, and the blank first organic phase and an iron zinc aluminum chloride solution are obtained. + +

[0212] Table 10 calcium extraction residual solution composition and content g / L

[0213] ​​ Co 2+ ]] Mn 2+ ]] Ni 2+ ]]> Fe 2+ ]] Al 3+ ]] Cu 2+ ]] Zn 2+ ]] Ca 2+ ]] Mg 2+ ]] pH 56.55 1.966 2.252 0.0006 0.0007 0.0094 0.010 0.068 6.37 2.47

[0214] (2) The second organic phase with a saponification rate of 50% (i.e. the volume fraction of P204 extractant is 20%, the diluent is sulfonated kerosene, and the saponification amount is 2.5 times the theoretical saponification amount) is used to extract the calcium extraction raffinate (Ca≤150 mg / L), the extraction phase ratio O / A=0.3:1, the extraction stage is 12, and the impurity-containing second organic phase and the impurity-containing second organic phase are obtained.

[0215] The impurity-containing second organic phase is sequentially subjected to impurity extraction section acid washing, impurity extraction section stripping, impurity extraction section reverse iron, and impurity extraction section water washing to obtain a blank second organic phase, which is used for impurity extraction after saponification; wherein the impurity extraction section acid washing acid washing phase ratio O / A=7.62:1, the washing stage is 7, the washing acid is H + 2 mol / L sulfuric acid; the impurity extraction section stripping phase ratio O / A=17.13:1, the stage is 6, the impurity extraction section stripping acid is H + 4.5 mol / L hydrochloric acid, the impurity extraction section reverse iron phase ratio O / A=70:1, the reverse iron stage is 3, and the reverse iron acid is H + 6.0 mol / L hydrochloric acid, the impurity extraction section water washing phase ratio O / A=28:1, the water washing stage is 1, and the acid-containing cobalt solution (Cu, Mn, Ca≤1 mg / L) and the calcium manganese chloride solution are obtained.

[0216] Table 11 Composition and content of impurity extraction raffinate g / L

[0217] Co 2+ ]] Mn 2+ ]] Ni 2+ ]]> Fe 2+ ]] Al 3+ ]]> Cu 2+ ]] Zn 2+ ]] Ca 2+ ]] Mg 2+ ]] pH 50.51 0.001 2.028 0.0007 0.0008 0.001 0.010 0.001 5.737 3.28

[0218] (3) The third organic phase with a saponification rate of 50% (i.e. the volume fraction of P507 extractant is 25%, the diluent is sulfonated kerosene) is used to extract the cobalt sulfate solution (Cu, Mn, Ca≤1 mg / L), the extraction phase ratio O / A=6.75:1, the extraction stage is 8, and the cobalt extraction raffinate and the cobalt-loaded third organic phase are obtained. The cobalt-loaded third organic phase is sequentially subjected to cobalt extraction section acid washing, cobalt extraction section sulfur washing, and cobalt extraction section stripping to obtain the third stripping solution and the impurity-containing third organic phase.

[0219] The cobalt-loaded third organic phase is sequentially subjected to cobalt extraction section acid washing, cobalt extraction section sulfur washing, cobalt extraction section stripping, cobalt extraction section reverse iron, and cobalt extraction section water washing to obtain a blank third organic phase, which is used for cobalt extraction after saponification; wherein the cobalt extraction section acid washing phase ratio O / A=18:1, the stage is 10, and the acid used is H + 2 mol / L sulfuric acid; the cobalt extraction section sulfur washing phase ratio O / A=18:1, the sulfur washing stage is 4, the cobalt extraction section stripping phase ratio O / A=18:1, the stage is 6, and the cobalt extraction section stripping acid is H + 4.5 mol / L hydrochloric acid, the cobalt extraction section reverse iron phase ratio O / A=289:1, the reverse iron stage is 2, and the reverse iron acid is H +6.0 mol / L hydrochloric acid, cobalt extraction section water washing phase O / A = 12:1, water washing stage 1, to obtain high-purity cobalt chloride solution and ammonium sulfate magnesium solution.

[0220] Table 12 High-purity cobalt chloride solution components and content g / L

[0221] Co 2+ ]] Mn 2+ ]] Ni 2+ ]]> Fe 2+ ]] Al 3+ ]] Cu 2+ ]]> Zn 2+ ]] Ca 2+ ]]> Mg 2+ ]]> pH 130.32 0.001 0.0004 0.0005 0.0003 0.0005 0.0006 0.0009 0.0009 2.23

[0222] The raw materials and wastewater production in the above examples and comparative examples were monitored, and the results are shown in Table 13.

[0223] Table 13 Key auxiliary material cost analysis of examples and comparative examples (calculated per ton of cobalt output)

[0224]

[0225] As can be seen from Table 13, examples 1 and 2 can reduce the amount of key auxiliary materials while ensuring that the impurity content of the high-purity cobalt chloride meets the requirements, which is conducive to reducing costs. The key auxiliary material cost of example 3 is similar to that of examples 1 and 2, but the impurity content of the produced cobalt chloride solution is higher.

[0226] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing cobalt chloride solution at low cost through segmented extraction, characterized in that, include: The first step involves calcium extraction using the first organic phase after soaping in the cobalt hydroxide leaching solution, yielding a calcium extraction residue and a first organic phase containing impurities; the volume fraction of p2O4 in the first organic phase is 10%–15%. The second-stage extraction process involves using a second organic phase after soaping to extract impurities from the calcium extraction residue, resulting in an extraction residue and a second organic phase containing impurities. The volume fraction of p2O4 in the second organic phase is 20%–25%. The three-stage cobalt extraction process involves using the third organic phase after soaping to extract cobalt from the remaining extract solution, resulting in a cobalt-loaded third organic phase. The cobalt-loaded third organic phase is then subjected to acid washing in the cobalt extraction stage, sulfur washing in the cobalt extraction stage, and back-extraction in the cobalt extraction stage, yielding a third back-extraction solution and a third organic phase containing impurities. The volume fraction of p507 in the third organic phase is 23%–27%. The four-stage extraction process involves extracting the third back-extraction solution with the fourth organic phase after soap conversion to obtain the raffinate and the impurity-containing fourth organic phase. The fourth organic phase after soap conversion is obtained by converting the fourth organic phase after soap conversion with the raffinate. The volume fraction of p204 in the fourth organic phase is 20% to 25%, and the raffinate is a cobalt chloride product.

2. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 1, characterized in that, The impurity-containing first organic phase is subjected to acid washing in the calcium extraction section, back-extraction in the calcium extraction section, iron removal in the calcium extraction section, and water washing in the calcium extraction section to obtain a blank first organic phase. The blank first organic phase is then saponified and used for calcium extraction. And / or, the saponification rate of the first organic phase after soaping is 20% to 25%; And / or, the first organic phase after soaping is obtained by reacting the first organic phase with the first saponifying agent.

3. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 2, characterized in that, The calcium extraction segment satisfies at least one of the following characteristics: a. The first organic phase further includes a first diluent, wherein the first diluent is selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane; b. The first saponifying agent is selected from ammonia water with a concentration of 18% to 20 wt%; c. In the calcium extraction step, the extraction ratio O / A is 0.7 to 0.85:1, and the number of extraction stages is 5 to 7. d. In the pickling step of the calcium extraction section, the pickling ratio O / A is 12-15:1, the number of pickling stages is 2-3, and the pickling agent used is H. + Sulfuric acid with a concentration of 0.2 mol / L to 0.4 mol / L; e. After acid washing in the calcium extraction stage, a first acid washing solution is obtained. The first acid washing solution is mixed with the cobalt hydroxide leaching solution to perform a first-stage calcium extraction. f. In the calcium extraction stage back-extraction step, the back-extraction ratio O / A is 30–62:1, the number of stages is 4–6, and the back-extraction acid used is H. + Hydrochloric acid with a concentration of 2.5 mol / L to 4.5 mol / L; g. In the antiferric step of calcium extraction, the antiferric ratio O / A is 88-100:1, the stage number is 1-3, and the antiferric acid used is H. + Hydrochloric acid with a concentration of 5.0 mol / L to 6.0 mol / L; h. After the calcium extraction section is de-ironized, the first de-ironized liquid is obtained, which is used to prepare the de-extraction acid for the calcium extraction section. i. In the calcium extraction stage, the water washing ratio O / A is 40-60:1, the washing stage is 1, and the washing agent is ultrapure water; j. After washing the calcium extraction section with water, a first washing solution is obtained. The first washing solution is used to prepare antiferric acid for the calcium extraction section.

4. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 1, characterized in that, The impurity-containing second organic phase was subjected to sequential acid washing in the impurity extraction section, back-extraction in the impurity extraction section, iron removal in the impurity extraction section, and water washing in the impurity extraction section to obtain a blank second organic phase, which was then saponified and used for impurity extraction. And / or, the saponification rate of the second organic phase after soaping is 45% to 55%; And / or, the first organic phase after soaping is obtained by reacting the first organic phase with the second saponifying agent.

5. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 4, characterized in that, The two-stage extraction and mixing satisfies at least one of the following characteristics: a. The second organic phase further includes a second diluent, the second diluent being selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane; b. The second saponifying agent is selected from ammonia water with a concentration of 18% to 20 wt%; c. In the extraction step, the extraction ratio O / A is 0.3 to 0.36:1, and the number of stages is 7 to 9; d. In the pickling step of the extraction section, the pickling ratio O / A is 17-22:1, the number of pickling stages is 6-8, and the pickling agent used is H. + Sulfuric acid with a concentration of 1.8 mol / L to 2.1 mol / L; e. After acid washing in the extraction stage, a second acid washing solution is obtained. The second acid washing solution is mixed with the calcium extraction residue for a two-stage extraction process. f. In the back-extraction step of the extraction stage, the back-extraction ratio O / A is 17–25:1, the number of stages is 5–6, and the back-extraction acid used is H. + Hydrochloric acid with a concentration of 4.0 mol / L to 4.5 mol / L; g. In the antiferric step of the extraction stage, the antiferric ratio O / A is 88–100:1, the stage number is 1–2, and the antiferric acid used is H. + Hydrochloric acid with a concentration of 5.0 mol / L to 6.0 mol / L; h. After the iron removal in the extraction section, a second iron removal solution is obtained, which is used to prepare the stripping acid for the extraction section. i. In the water washing step of the extraction section, the water washing ratio O / A is 40-60:1, the stage is 1, and the detergent used is ultrapure water; j. After washing the extracted section with water, a second washing solution is obtained, which is used to prepare antiferric acid for antiferric extraction of the extracted section; k. The concentrations of Cu, Mn, and Ca in the residual extract are all less than 8 mg / L, and the main component of the solute is cobalt sulfate.

6. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 1, characterized in that, The cobalt-loaded third organic phase was subjected to acid washing in the cobalt extraction section, sulfur washing in the cobalt extraction section, back-extraction in the cobalt extraction section, iron removal in the cobalt extraction section, and water washing in the cobalt extraction section to obtain a blank third organic phase, which was then saponified and used for cobalt extraction. And / or, the saponification rate of the third organic phase after soaping is 48% to 60%; And / or, the third organic phase after soaping is obtained by reacting the third organic phase with a third saponifying agent.

7. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 6, characterized in that, The three-stage cobalt extraction process satisfies at least one of the following characteristics: a. The third organic phase further includes a third diluent, which is selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane; b. The third saponifying agent is selected from ammonia water with a concentration of 18% to 20 wt%; c. In the cobalt extraction step, the extraction ratio O / A is 6.9–7.5:1, and the number of extraction stages is 7–8. d. In the cobalt extraction pickling step, the pickling ratio O / A is 13.8–19.2:1, the number of pickling stages is 7–10, and the pickling agent used is H. + Sulfuric acid with a concentration of 1.5 mol / L to 2.1 mol / L; e. After acid washing in the cobalt extraction stage, a third acid washing solution is obtained, which is then mixed with the residual extraction solution to perform three-stage cobalt extraction; f. After sulfur washing in the cobalt extraction section, a third sulfur washing solution is obtained, which is mixed with sulfuric acid and used as the acid washing solution for the cobalt extraction section. g. In the cobalt extraction stage, the O / A ratio is 17–19:1, the number of stages is 6–7, and the extraction acid used is H. + Hydrochloric acid with a concentration of 4.5 mol / L to 4.8 mol / L; h. The total concentration of Cu, Mn, and Ca in the third back-extraction solution is less than 20 mg / L, and the main component of the solute is cobalt chloride; i. In the cobalt extraction stage, the antiferric ratio (O / A) is 300–350:1, and the stage number is 1–2. The antiferric acid used is H₂O. + Hydrochloric acid with a concentration of 5.0 mol / L to 6.0 mol / L; j. After the cobalt extraction section is de-ironized, a third de-ironized liquid is obtained, which is used to prepare the de-extraction acid for the cobalt extraction section; k. In the cobalt extraction section, the water washing ratio O / A is 5 to 15:1, the washing stage is 1, and the washing agent used is ultrapure water; l. A third washing solution is obtained after washing the cobalt extraction section with water, and the third washing solution is used to prepare antiferric acid for the cobalt extraction section; In the sulfur washing step of the cobalt extraction section, the sulfur washing ratio O / A is 18-18.5:1, the number of sulfur washing stages is 2-3, and the washing acid is H. + Sulfuric acid with a concentration of 1.8 mol / L to 2 mol / L.

8. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 1, characterized in that, The impurity-containing fourth organic phase is washed with water to obtain a copper-manganese-calcium-cobalt fourth organic phase, which is then returned to the second-stage extraction step. And / or, the saponification rate of the fourth organic phase after soaping is 45% to 55%; And / or, the fourth organic phase after soaping is obtained by reacting the fourth organic phase with the fourth saponifying agent; And / or, during the saponification process of the fourth organic phase, the amount of reagent saponified is 2.5 to 3.5 times the theoretical amount of saponification.

9. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 8, characterized in that, The four-stage extraction satisfies at least one of the following characteristics: a. The fourth organic phase further includes a fourth diluent, which is selected from at least one of cyclohexane, sulfonated kerosene, and n-dodecane; b. The fourth saponifying agent is selected from ammonia water with a concentration of 18% to 20 wt%; c. In the soap-making process, the ratio of O to A is 10-12:1, and the soap grade is 7-8. d. After the soap conversion, an extraction washing stage is performed. In the extraction washing stage, the water washing ratio O / A is 20-30:1, and the number of washing stages is 1-2. e. In the extraction step, the extraction ratio O / A is 0.01 to 0.02:1, and the number of extraction stages is 7 to 9. f. In the chloride washing step, the chloride ratio of O / A is 5 to 15:1, and the stage number is 1.

10. The method for preparing cobalt chloride solution at low cost by segmented extraction according to claim 1, characterized in that, The cobalt ion concentration in the cobalt hydroxide leaching solution is 55 g / L to 65 g / L. And / or, the pH of the cobalt hydroxide leaching solution is 2.0 to 2.2; And / or, the concentration of manganese ions in the cobalt hydroxide leachate is 2.5 g / L to 3.5 g / L, the concentration of nickel ions is 2 to 2 g / L to 2.5 g / L, the concentration of magnesium ions is 6 g / L to 7.5 g / L, the concentration of iron ions is less than 0.01 g / L, the concentration of aluminum ions is less than 0.01 g / L, and the concentration of copper ions is less than 0.02 g / L.

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