Impurity removal method of crude nickel cobalt hydroxide

Abstract

The invention provides an impurity removal method of crude cobalt nickel hydroxide. The impurity removal method comprises the following steps: dissolving the crude cobalt nickel hydroxide by adopting a first acid solution to obtain a mixed acid solution; adsorbing the mixed acid solution by using amino phosphorus-containing resin to remove iron, scandium and part of aluminum; adding first alkali liquor into the solution subjected to adsorption and impurity removal for precipitation, and carrying out solid-liquid separation to obtain aluminum hydroxide precipitate and a solution subjected to trivalent ion impurity removal; carrying out acid desorption treatment on the adsorbed resin by adopting a second acid solution to obtain an acid desorption solution containing iron and aluminum and acid desorption resin, and carrying out alkali desorption treatment on the acid desorption resin by adopting a second alkali solution to obtain an alkali desorption solution containing scandium and alkali desorption resin; and S5, precipitating the scandium-containing alkaline desorption solution by adopting third alkali liquor to obtain scandium hydroxide, so that the problems that in the prior art, trivalent ions in crude nickel cobalt hydroxide are easy to accumulate in an oil phase, so that an extracting agent is poisoned, and the trivalent ions are difficult to independently recover are solved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for removing impurities from crude nickel-cobalt hydroxide. Background Art

[0002] Crude nickel cobalt hydroxide is the main raw material for producing nickel cobalt manganese (NCM) ternary precursor. In the prior art, crude nickel cobalt hydroxide is mainly produced by leaching-purification-extraction and other production processes to produce nickel sulfate solution, cobalt sulfate solution, and manganese sulfate solution, and then mixed in a certain proportion, and the NCM precursor is produced by the production process of synthesis-aging-drying-screening-magnetic removal-packaging. Crude cobalt hydroxide often contains some iron, aluminum and a small amount of scandium. After acid dissolution, if directly extracted, these trivalent ions are very easy to accumulate in the oil phase, causing extractant poisoning. The content of the three elements in crude nickel cobalt hydroxide is usually the highest in aluminum, and iron and scandium are less. Therefore, aluminum has a certain recovery value, and scandium is a rare earth metal and also has a certain recovery value. At present, most projects use precipitation to remove, but the pH of iron, aluminum, and scandium precipitation is very close, and the three precipitations are mixed in the slag, and it is difficult to recover any one of the metals. Therefore, it is of great significance to develop a decontamination process that can solve the problem of trivalent ions before extraction of crude nickel cobalt hydroxide and obtain aluminum and scandium byproducts at the same time. Summary of the invention

[0003] The main purpose of the present invention is to provide a method for removing impurities from crude nickel cobalt hydroxide to solve the problem in the prior art that trivalent ions in crude nickel cobalt hydroxide are easily accumulated in the oil phase, causing extractant poisoning and difficulty in recovering trivalent ions alone.

[0004] In order to achieve the above object, according to one aspect of the present invention, a method for removing impurities from crude nickel cobalt hydroxide is provided, comprising the following steps:

[0005] Step S1, using a first acid solution to dissolve crude nickel cobalt hydroxide to obtain a mixed acid solution, wherein the pH of the mixed acid solution is 0.5 to 2.5;

[0006] Step S2, using an amino phosphorus-containing resin to adsorb the mixed acidic solution to remove iron, scandium and part of aluminum, to obtain an adsorbed resin and an adsorbed and impurity-removed solution;

[0007] Step S3, adding a first alkali solution to the solution after adsorption and impurity removal for precipitation, controlling the precipitation endpoint pH to be greater than 3 and less than 3.7, obtaining a mixed system containing aluminum hydroxide precipitate, and performing solid-liquid separation on the mixed system containing aluminum hydroxide precipitate to obtain aluminum hydroxide precipitate and a solution after trivalent ion impurity removal;

[0008] Step S4, using a second acid solution to perform acid desorption treatment on the adsorbed resin to obtain an acid desorption solution and an acid desorption resin containing iron and aluminum, and using a second alkali solution to perform alkali desorption treatment on the acid desorption resin to obtain an alkaline desorption solution and an alkaline desorption resin containing scandium; the concentration of hydrogen ions in the second acid solution is greater than or equal to 1 mol / L; the second alkali solution is a sodium carbonate solution with a pH of 9 to 11.6;

[0009] Step S5, using a third alkaline solution to precipitate the scandium-containing alkaline desorption solution to obtain scandium hydroxide.

[0010] Furthermore, the amino phosphorus-containing resin is selected from one of TP260 and S950.

[0011] Preferably, step S4 further comprises washing the alkaline desorption resin with water until the pH of the effluent is ≤9, and the washed alkaline desorption resin is repeatedly used in step S2.

[0012] Preferably, the acidic desorption solution containing iron and aluminum obtained in step S4 is returned to step S1 and added to the first acid solution for repeated use.

[0013] Furthermore, the pH of the mixed acidic solution is 1-2.

[0014] Furthermore, the concentration of hydrogen ions in the second acid solution is 2 mol / L to 8 mol / L.

[0015] Furthermore, the pH of the second alkali solution is 11-12.

[0016] Furthermore, the first acid solution includes a first acidic substance and water, and the first acidic substance is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid.

[0017] Furthermore, the second acid solution includes a second acidic substance and water, and the second acidic substance is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid.

[0018] Furthermore, the first alkaline solution includes a first alkaline substance and water, and the first alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, and ammonia water.

[0019] Furthermore, the concentration of hydroxide ions in the first alkali solution is greater than or equal to 1 mol / L.

[0020] Furthermore, the third alkaline solution includes a third alkaline substance and water, and the third alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide solution, and ammonia water.

[0021] Furthermore, the concentration of hydroxide ions in the third alkali solution is greater than or equal to 1 mol / L.

[0022] Furthermore, in the mixed acidic solution, the concentration of nickel ions is 50 g / L to 100 g / L, the concentration of cobalt ions is 1 g / L to 15 g / L, the concentration of iron ions is 10 mg / L to 70 mg / L, the concentration of aluminum ions is 100 mg / L to 300 mg / L, and the concentration of scandium ions is 10 mg / L to 70 mg / L.

[0023] Furthermore, the mixed acidic solution also includes magnesium ions, manganese ions, zinc ions and copper ions. In the mixed acidic solution, the concentration of magnesium ions is 1g / L to 10g / L, the concentration of manganese ions is 5g / L to 15g / L, the concentration of zinc ions is 1g / L to 3g / L, and the concentration of copper ions is 100mg / L to 300mg / L.

[0024] Furthermore, in the solution after the trivalent ion impurities are removed, the concentrations of aluminum ions, iron ions, and scandium ions are all lower than 0.5 mg / L.

[0025] By using the technical scheme of the present invention, the crude nickel cobalt hydroxide raw material is firstly acid-dissolved, and then the iron, scandium and part of the aluminum are separated by adsorption through amino phosphorus-containing resin, and then the iron, aluminum and scandium are separated by graded desorption (firstly the resin after adsorption is subjected to acid desorption treatment with a second acid solution to obtain an acidic desorption solution containing iron and aluminum, and then the acid desorption resin is subjected to alkaline desorption treatment with a second alkaline solution to obtain an alkaline desorption solution containing scandium); the alkaline desorption solution containing scandium obtained by separation is precipitated with a third alkaline solution to obtain a by-product of scandium hydroxide. The invention discloses a product, wherein the acid desorption resin is firstly subjected to alkaline desorption treatment with a second alkaline solution to obtain an alkaline desorption solution containing scandium, and then the alkaline desorption solution containing scandium is subjected to precipitation treatment with a third alkaline solution, which can effectively avoid the pores of the resin being blocked by the precipitated crystals, so as to fully separate scandium and the resin and to recycle the resin; the adsorption impurity-removed solution from which iron, scandium and part of aluminum are adsorbed and removed can be used to recover aluminum through a precipitation method, and at the same time, the obtained trivalent ion impurity-removed solution meets the requirements of the nickel-cobalt extraction stock solution and can enter the subsequent extraction process.

[0026] The method for removing impurities from crude nickel cobalt hydroxide of the present invention can solve the problem that trivalent ions are very likely to accumulate in the oil phase before extraction of crude nickel cobalt hydroxide, causing poisoning of the extractant, and scandium and aluminum are recovered respectively, thereby improving the economic value of the crude nickel cobalt hydroxide. The impurity removal process is short and the reagent components used are simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 A schematic flow chart of a method for removing impurities from crude nickel cobalt hydroxide according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] As described in the background art, in the prior art, trivalent ions of iron, aluminum and scandium in crude nickel cobalt hydroxide are easily accumulated in the oil phase, causing the problem of extractant poisoning and difficulty in recovering trivalent ions alone. In order to solve the above problems, according to one aspect of the present invention, Figure 1 As shown, a method for removing impurities from crude nickel cobalt hydroxide is provided, comprising the following steps:

[0031] Step S1, using a first acid solution to dissolve crude nickel cobalt hydroxide to obtain a mixed acid solution, wherein the pH of the mixed acid solution is 0.5 to 2.5;

[0032] Step S2, using an amino phosphorus-containing resin to adsorb the mixed acidic solution to remove iron (removed in the form of trivalent iron ions), scandium (removed in the form of trivalent scandium ions) and part of aluminum (removed in the form of aluminum ions), to obtain an adsorbed resin and an adsorbed and impurity-removed solution;

[0033] Step S3, adding a first alkali solution to the solution after adsorption and impurity removal for precipitation, controlling the precipitation endpoint pH to be greater than 3 and less than 3.7, obtaining a mixed system containing aluminum hydroxide precipitate, and performing solid-liquid separation on the mixed system containing aluminum hydroxide precipitate to obtain aluminum hydroxide precipitate and a solution after trivalent ion impurity removal;

[0034] Step S4, using a second acid solution to perform acid desorption treatment on the adsorbed resin to obtain an acid desorption solution and an acid desorption resin containing iron and aluminum, and using a second alkali solution to perform alkali desorption treatment on the acid desorption resin to obtain an alkaline desorption solution and an alkaline desorption resin containing scandium; the concentration of hydrogen ions in the second acid solution is greater than or equal to 1 mol / L; the second alkali solution is a sodium carbonate solution with a pH of 9 to 11.6;

[0035] Step S5, using a third alkaline solution to precipitate the scandium-containing alkaline desorption solution to obtain scandium hydroxide.

[0036] The impurity removal method of the crude nickel cobalt hydroxide according to the present invention comprises the following steps: firstly, the crude nickel cobalt hydroxide raw material is acid-dissolved, and then the iron, scandium and part of aluminum are separated by adsorption through an amino phosphorus-containing resin, and then the iron, aluminum and scandium are separated by graded desorption (firstly, the resin after adsorption is subjected to acid desorption treatment with a second acid solution to obtain an acidic desorption solution containing iron and aluminum, and then the acid desorption resin is subjected to alkaline desorption treatment with a sodium carbonate aqueous solution to obtain an alkaline desorption solution containing scandium); the alkaline desorption solution containing scandium obtained by separation is precipitated by a third alkaline solution to obtain nickel hydroxide; Scandium byproduct, wherein the acid desorption resin is first subjected to alkaline desorption treatment with a sodium carbonate aqueous solution to obtain an alkaline desorption solution containing scandium, and then the alkaline desorption solution containing scandium is subjected to precipitation treatment with a third alkaline solution, which can effectively avoid the precipitated crystals from blocking the pores of the resin, so as to fully separate scandium and the resin and recycle the resin; the adsorption impurity removal solution from which iron, scandium and part of aluminum are adsorbed and removed can be used to recover aluminum by precipitation, and at the same time, the obtained trivalent ion impurity removal solution meets the requirements of the nickel-cobalt extraction stock solution and can enter the subsequent extraction process. The impurity removal method of the crude nickel-cobalt hydroxide of the present invention can solve the problem that trivalent ions are very easy to accumulate in the oil phase before the extraction of the crude nickel-cobalt hydroxide, causing poisoning of the extractant, and scandium and aluminum are recovered separately, thereby improving the economic value of the crude nickel-cobalt hydroxide, and the impurity removal process is short and the reagent components used are simple.

[0037] In some embodiments, the amino phosphorus-containing resin is selected from one of TP260 or S950.

[0038] In the technical solution of the embodiment of the present application, TP260 and S950 resins can efficiently and selectively remove trivalent impurity cations of iron, aluminum, and scandium from the mixed acidic solution due to their high exchange capacity and selectivity, without affecting the recovery rate of nickel and cobalt. This selective removal method can significantly improve the purity of the nickel-cobalt solution, reduce the complexity and cost of subsequent processing steps, and is suitable for large-scale industrial production, especially in the production process of new energy vehicle battery materials, where the purity of raw materials is extremely high. This impurity removal method can effectively meet this demand.

[0039] In some preferred embodiments, step S4 further comprises washing the alkaline desorption resin with water until the pH of the effluent is ≤9, and the washed alkaline desorption resin is repeatedly used in step S2.

[0040] In the technical solution of the embodiment of the present application, the alkaline desorption resin can be reused in step S2 after being cleaned, and is used to adsorb and remove iron, scandium and part of aluminum again, which is economical, environmentally friendly and has a high removal rate.

[0041] In some preferred embodiments, the acidic desorption solution containing iron and aluminum obtained in step S4 is returned to step S1 and added to the first acid solution for repeated use.

[0042] In the technical solution of the embodiment of the present application, the acidic desorption liquid containing iron and aluminum is returned to the first acid liquid for dissolving crude nickel cobalt hydroxide, which can improve the resource utilization rate of the acidic substance, and subsequently through adsorption and graded desorption by amino phosphorus-containing resin, the iron and aluminum in the acidic desorption liquid containing iron and aluminum can be concentrated for subsequent centralized treatment.

[0043] In some embodiments, the pH of the mixed acidic solution is 1-2.

[0044] In the technical solution of the embodiment of the present application, at the above pH, the amino-phosphorus-containing resin has a higher adsorption effect on scandium and iron, and the amino-phosphorus-containing resin co-adsorbs less divalent ions such as nickel and cobalt.

[0045] In some embodiments, the concentration of hydrogen ions in the second acid solution is 2 mol / L to 8 mol / L.

[0046] In the technical solution of the embodiment of the present application, the use of the second acid solution with the above-mentioned hydrogen ion concentration is conducive to the sufficient desorption of trivalent iron ions and trivalent aluminum ions so as to facilitate the subsequent alkaline desorption treatment and precipitation treatment to obtain scandium hydroxide with higher purity, and avoid excessive use of acid to avoid waste of resources.

[0047] In some embodiments, the pH of the second alkaline solution is 10-11.

[0048] In the technical scheme of the embodiment of the present application, by using a sodium carbonate solution in a specific pH range as the second alkaline solution, scandium can be effectively desorbed from the resin. At the same time, since the desorption pH range of scandium is different from that of metals such as iron and aluminum, this specific pH value ensures the high purity and high recovery rate of scandium, while impurities such as iron and aluminum remain in the acidic desorption solution. In some embodiments, the pH of the second alkaline solution is 10 to 11, which is conducive to the efficient desorption and high recovery rate of scandium, and is also conducive to reducing the destruction of the structure of amino-phosphorus-containing resins or excessive alkalization of active groups, thereby ensuring the regeneration performance of amino-phosphorus-containing resins.

[0049] In some embodiments, the first acid solution includes a first acidic substance and water, and the first acidic substance is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid.

[0050] In some embodiments, the second acid solution includes a second acidic substance and water, and the second acidic substance is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid.

[0051] In some embodiments, the first alkaline solution includes a first alkaline substance and water, and the first alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, and ammonia water.

[0052] In some embodiments, the first alkaline solution includes a first alkaline substance and water, and the first alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, and ammonia water.

[0053] In some embodiments, the concentration of hydroxide ions in the first alkaline solution is greater than or equal to 1 mol / L to facilitate efficient precipitation and separation of aluminum hydroxide.

[0054] In some embodiments, the third alkaline solution includes a third alkaline substance and water, and the third alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide solution, and ammonia water.

[0055] In some embodiments, the concentration of hydroxide ions in the third alkaline solution is greater than or equal to 1 mol / L to facilitate efficient precipitation and separation of scandium hydroxide.

[0056] In some embodiments, in the mixed acidic solution, the concentration of nickel ions is 50 g / L to 100 g / L, the concentration of cobalt ions is 1 g / L to 15 g / L, the concentration of iron ions is 10 mg / L to 70 mg / L, the concentration of aluminum ions is 100 mg / L to 300 mg / L, and the concentration of scandium ions is 10 mg / L to 70 mg / L.

[0057] In the technical solution of the embodiment of the present application, each ion in the mixed acidic solution has a high trivalent ion impurity removal rate and a high aluminum hydroxide and scandium hydroxide recovery rate within the above concentration range.

[0058] In some embodiments, the mixed acidic solution also includes magnesium ions, manganese ions, zinc ions and copper ions. In the mixed acidic solution, the concentration of magnesium ions is 1g / L to 10g / L, the concentration of manganese ions is 5g / L to 15g / L, the concentration of zinc ions is 1g / L to 3g / L, and the concentration of copper ions is 100mg / L to 300mg / L.

[0059] In the technical scheme of the embodiment of the present application, in the process of using amino phosphorus-containing resin to adsorb the mixed acidic solution to remove iron, scandium and part of the aluminum, divalent impurity ions of magnesium ions, manganese ions, zinc ions and copper ions enter the adsorption and impurity removal solution along with nickel ions and cobalt ions, and in the process of preparing aluminum hydroxide precipitate, enter the trivalent ion impurity removal solution along with nickel and cobalt ions; at the above-mentioned divalent impurity ion concentration, the obtained trivalent ion impurity removal solution can meet the requirements of the nickel-cobalt extraction stock solution and can enter the subsequent extraction process, and the obtained scandium hydroxide product and aluminum hydroxide product have a low content of divalent impurity ions and high purity.

[0060] In some embodiments, in the solution after trivalent ion impurity removal, the concentrations of aluminum ions, iron ions, and scandium ions are all lower than 0.5 mg / L. Within the above concentration range, the content of trivalent ions in the solution after trivalent ion impurity removal is significantly reduced, and the solution can be used as a nickel-cobalt extraction stock solution to enter the subsequent extraction process.

[0061] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0062] Example 1

[0063] A method for removing impurities from crude nickel cobalt hydroxide comprises the following steps:

[0064] Step 1, using a sulfuric acid aqueous solution to dissolve crude nickel cobalt hydroxide to obtain a mixed acid solution, the pH of the mixed acid solution is 2.0; wherein the concentration of major ions in the mixed acid solution is shown in Table 1;

[0065] Step 2, using amino phosphorus-containing resin to adsorb the mixed acidic solution to remove iron, scandium and part of aluminum, to obtain adsorbed resin and adsorbed impurity-removed solution; the amino phosphorus-containing resin is commercially available TP260;

[0066] Step three, adding 5 mol / L sodium hydroxide aqueous solution to the solution after adsorption and impurity removal for precipitation, controlling the precipitation end point pH to 3.5, obtaining a mixed system containing aluminum hydroxide precipitate, and performing solid-liquid separation on the mixed system containing aluminum hydroxide precipitate to obtain aluminum hydroxide precipitate and a solution after trivalent ion impurity removal; the concentrations of major ions in the solution after trivalent ion impurity removal are shown in Table 2.

[0067] Step 4, using 3 mol / L sulfuric acid aqueous solution to acid desorb the resin after adsorption, iron and co-adsorbed aluminum enter the acid desorption solution, and obtain an acid desorption solution containing iron and aluminum and an acid desorption resin, and using a sodium carbonate aqueous solution with a pH of 11 to alkaline desorb the acid desorption resin, and scandium enters the alkaline desorption solution to obtain an alkaline desorption solution and an alkaline desorption resin containing scandium; wherein, the concentration of major ions in the acid desorption solution containing iron and aluminum is shown in Table 3; the acid desorption solution containing iron and aluminum is returned to the sulfuric acid aqueous solution in step 1 for the next round of crude nickel cobalt hydroxide dissolution, and the composition of major ions in the alkaline desorption solution containing scandium is shown in Table 4; water is passed into the alkaline desorption resin for cleaning until the pH of the outlet water is 8, so that it can be reused in the next round, and the mixed acidic solution is adsorbed to remove iron, scandium and part of the aluminum;

[0068] Step S5, using a 5 mol / L sodium hydroxide aqueous solution to precipitate the scandium-containing alkaline desorption solution to obtain scandium hydroxide.

[0069] Example 2

[0070] The only difference from Example 1 is that in step 4, 1 mol / L sulfuric acid aqueous solution is used to carry out acid desorption treatment on the adsorbed resin.

[0071] Example 3

[0072] The only difference between it and Example 1 is that a sodium carbonate aqueous solution with a pH of 9 is used in step 4.

[0073] Example 4

[0074] The only difference from Example 1 is that a sodium carbonate aqueous solution with a pH of 11.6 is used in step 4.

[0075] Table 1. Concentrations of major ions in mixed acidic solutions

[0076]

[0077]

[0078] Table 2. Concentration of major ions in the solution after trivalent ion removal

[0079] <![CDATA[Ni 2+ (g / L)]]> <![CDATA[Co 2+ (g / L)]]> <![CDATA[Fe 3+ (mg / L)]]> <![CDATA[Al 3+ (mg / L)]]> <![CDATA[Sc 3+ (mg / L)]]> <![CDATA[Mg 2+ (g / L)]]> <![CDATA[Mn 2+ (g / L)]]> <![CDATA[Zn 2+ (g / L)]]> <![CDATA[Cu 2+ (mg / L)]]> 93.5 7.5 ＜0.1 ＜0.1 ＜0.1 4.0 9.8 1.5 176

[0080] Table 3. Concentrations of major ions in the acidic desorption solutions containing iron and aluminum

[0081] Ni(mg / L) Co(mg / L) Fe(mg / L) Al(mg / L) Sc(mg / L) Mg(mg / L) Mn(mg / L) Zn(mg / L) Cu(mg / L) 544.7 59.9 19.6 122.3 1.5 42.7 1355.2 794.7 116.1

[0082] Table 4. Concentrations of major ions in alkaline desorption solutions containing scandium

[0083] <![CDATA[Ni 2+ (mg / L)]]> <![CDATA[Co 2+ (mg / L)]]> <![CDATA[Fe 3+ (mg / L)]]> <![CDATA[Al 3+ (mg / L)]]> <![CDATA[Sc 3+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> <![CDATA[Mn 2+ (mg / L)]]> <![CDATA[Zn 2+ (mg / L)]]> <![CDATA[Cu 2+ (mg / L)]]> ＜0.1 ＜0.1 ＜0.1 ＜0.1 148.5 ＜0.1 ＜0.1 ＜0.1 ＜0.1

[0084] The recovery rate of aluminum, the recovery rate of scandium, the impurity content in the aluminum hydroxide product and the impurity content in the scandium hydroxide product of Examples and 1-4 are shown in Table 5.

[0085] Table 5. Aluminum recovery, scandium recovery, impurity content in aluminum hydroxide product, and impurity content in scandium hydroxide product

[0086] Aluminum recovery rate (%) Recovery rate of scandium (%) Impurity content in aluminum hydroxide products (%) Impurity content in scandium hydroxide products (%) Example 1 70％ 89％ ≤10％ ≤10％ Example 2 70％ 89％ ≤10％ ≤10％ Example 3 70％ 85％ ≤10％ ≤10％ Example 4 70％ 92％ ≤10％ ≤10％

[0087] Comparative Example 1

[0088] The only difference from Example 1 is that in step 4, a 0.2 mol / L sulfuric acid second acid aqueous solution is used to perform acid desorption treatment on the adsorbed resin. Too low acidity results in that iron and aluminum are basically unable to be desorbed, and the resin cannot be recycled.

[0089] Comparative Example 2

[0090] The only difference from Example 1 is that a sodium carbonate aqueous solution with a pH of 8.5 is used in step 4. Too low alkalinity makes it difficult to desorb scandium, the scandium recovery rate is less than 20%, and the resin cannot be recycled.

[0091] Comparative Example 3

[0092] The only difference from Example 1 is that in step 4, a sodium hydroxide aqueous solution with a pH of 12 is used. After the desorption of scandium, scandium hydroxide precipitates are directly generated, which blocks the pores of the resin, and the scandium recovery rate is less than 5%, and the resin cannot be reused.

[0093] As can be seen from Table 5, based on the impurity removal method of crude nickel cobalt hydroxide of Examples 1-4 of the present invention, the crude nickel cobalt hydroxide raw material is first acid-dissolved, and then the iron, scandium and part of the aluminum are separated by adsorption through amino phosphorus-containing resin, and then the iron, aluminum and scandium are separated by graded desorption (first the resin after adsorption is subjected to acid desorption treatment with aqueous sulfuric acid to obtain an acidic desorption solution containing iron and aluminum, and then the acid desorption resin is subjected to alkaline desorption treatment with aqueous sodium carbonate to obtain an alkaline desorption solution containing scandium), and the separated alkaline desorption solution containing scandium is precipitated with aqueous sodium hydroxide to obtain a scandium hydroxide product, and the adsorption impurity removal solution from which iron, scandium and part of the aluminum are adsorbed and removed is obtained by precipitation to obtain an aluminum hydroxide product, and finally a higher aluminum recovery rate and a scandium recovery rate are obtained, and the aluminum hydroxide product and the aluminum hydroxide product have low impurity contents, and the iron, aluminum and scandium concentrations in the solution after trivalent ion impurity removal are all lower than 0.1 mg / L, and the trivalent ion content is significantly reduced, so the solution can be used as a nickel cobalt extraction stock solution to enter the subsequent extraction process.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for removing impurities from crude nickel cobalt hydroxide, characterized in that: The steps include: Step S1, using a first acid solution to dissolve crude nickel cobalt hydroxide to obtain a mixed acid solution, wherein the pH of the mixed acid solution is 0.5 to 2.5; Step S2, using an amino phosphorus-containing resin to adsorb the mixed acidic solution to remove iron, scandium and part of aluminum, thereby obtaining an adsorbed resin and an adsorbed and impurity-removed solution; Step S3, adding a first alkali solution to the adsorption and impurity removal solution to perform precipitation, controlling the precipitation endpoint pH to be greater than 3 and less than 3.7, to obtain a mixed system containing aluminum hydroxide precipitate; performing solid-liquid separation on the mixed system containing aluminum hydroxide precipitate to obtain aluminum hydroxide precipitate and a trivalent ion impurity removal solution; Step S4, using a second acid solution to perform acid desorption treatment on the adsorbed resin to obtain an acid desorption solution and an acid desorption resin containing iron and aluminum, and using a second alkali solution to perform alkaline desorption treatment on the acid desorption resin to obtain an alkaline desorption solution and an alkaline desorption resin containing scandium; the concentration of hydrogen ions in the second acid solution is greater than or equal to 1 mol / L; the second alkali solution is a sodium carbonate solution with a pH of 9 to 11.6; Step S5, using a third alkaline solution to precipitate the scandium-containing alkaline desorption solution to obtain scandium hydroxide.

2. The impurity removal method of crude nickel cobalt hydroxide according to claim 1, characterized in that: The amino phosphorus-containing resin is selected from one of TP260 and S950; preferably, The step S4 further comprises washing the alkaline desorption resin with water until the pH of the effluent is less than or equal to 9, and repeatedly using the washed alkaline desorption resin in the step S2; and / or, The acidic desorption solution containing iron and aluminum obtained in step S4 is returned to step S1 and added into the first acid solution for repeated use.

3. The impurity removal method of crude nickel cobalt hydroxide according to claim 1, characterized in that: The pH of the mixed acidic solution is 1-2.

4. The impurity removal method of crude nickel cobalt hydroxide according to claim 1, characterized in that: The concentration of hydrogen ions in the second acid solution is 2 mol / L to 8 mol / L.

5. The impurity removal method of crude nickel cobalt hydroxide according to claim 1, characterized in that: The pH of the second alkali solution is 11-12.

6. The method for removing impurities from crude nickel and cobalt hydroxide according to any one of claims 1 to 5, characterized in that: The first acid solution comprises a first acidic substance and water, wherein the first acidic substance is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid; and / or, The second acid solution includes a second acidic substance and water, and the second acidic substance is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid.

7. The method for removing impurities from crude nickel and cobalt hydroxide according to any one of claims 1 to 5, characterized in that: The first alkaline solution comprises a first alkaline substance and water, wherein the first alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, and ammonia water; and / or, The concentration of hydroxide ions in the first alkali solution is greater than or equal to 1 mol / L; The third alkali solution comprises a third alkaline substance and water, wherein the third alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide solution, and ammonia water; and / or, The concentration of hydroxide ions in the third alkali solution is greater than or equal to 1 mol / L.

8. The method for removing impurities from crude nickel and cobalt hydroxide according to any one of claims 1 to 5, characterized in that: In the mixed acidic solution, the concentration of nickel ions is 50 g / L to 100 g / L, the concentration of cobalt ions is 1 g / L to 15 g / L, the concentration of iron ions is 10 mg / L to 70 mg / L, the concentration of aluminum ions is 100 mg / L to 300 mg / L, and the concentration of scandium ions is 10 mg / L to 70 mg / L.

9. The method for removing impurities from crude nickel and cobalt hydroxide according to any one of claims 1 to 5, characterized in that: The mixed acidic solution also includes magnesium ions, manganese ions, zinc ions and copper ions. In the mixed acidic solution, the concentration of the magnesium ions is 1g / L to 10g / L, the concentration of the manganese ions is 5g / L to 15g / L, the concentration of the zinc ions is 1g / L to 3g / L, and the concentration of the copper ions is 100mg / L to 300mg / L.

10. The method for removing impurities from crude nickel and cobalt hydroxide according to any one of claims 1 to 5, characterized in that: In the solution after the trivalent ion impurities are removed, the concentrations of aluminum ions, iron ions and scandium ions are all lower than 0.5 mg / L.

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