Method for removing impurities from nickel-cobalt-manganese mixed solution

Abstract

The invention discloses a method for removing impurities from a nickel-cobalt-manganese mixed solution, which comprises the following steps: adding a first alkali solution into the nickel-cobalt-manganese mixed solution to obtain a first treatment solution with the pH value of a (2lt; a < lt >; 3.2); second alkali liquor is added into the first treating fluid to obtain second treating fluid with the pH value of b, and the pH value of the second treating fluid is 2.5 lt; blt; 4; performing filtration treatment and solid-liquid separation treatment on the second treatment liquid to obtain impurity-removed slag and filtrate containing nickel, cobalt and manganese; wherein the first alkali liquid comprises sodium ions and / or potassium ions, the pH value of the first treatment liquid is controlled, so that Fe < 3 + > in the nickel-cobalt-manganese mixed solution is converted into sodium jarosite precipitate, and the sodium jarosite precipitate can adsorb Al < 3 + >; and / or Al < 3 + > is converted into jarosite precipitate, and the jarosite precipitate can adsorb Fe < 3 + >, so that the removal rate of Fe < 3 + > and Al < 3 + > is increased; and then the pH value of the second treatment liquid is controlled, so that fine ferric hydroxide colloid and aluminum hydroxide colloid in the reaction system are converted into precipitates, large-particle precipitates are effectively intercepted, and the filtering rate and the impurity removal efficiency of the reaction system are improved.

Description

Technical Field

[0001] This application relates to the field of waste battery recycling, and specifically, to a method for removing impurities from a nickel-cobalt-manganese mixed solution. Background Art

[0002] During the waste battery recycling process, a nickel-cobalt-manganese mixed solution can be refined. However, in addition to the target elements nickel, cobalt, and manganese, the mixed solution inevitably contains impurity elements. These impurity elements will interfere with the separation and purification process of the target elements, reduce the refining efficiency, and result in a decrease in the purity and performance of the final nickel-cobalt-manganese products. Therefore, there is an urgent need for a method to effectively remove impurity elements from the nickel-cobalt-manganese mixed solution.

[0003] It should be noted that the above statements are only used to provide background technical information related to this application, and do not necessarily constitute prior art. Summary of the Invention

[0004] In a first aspect of this application, this application provides a method for removing impurities from a nickel-cobalt-manganese mixed solution, including: adding a first alkali solution to the nickel-cobalt-manganese mixed solution to obtain a first treatment solution with a pH of a, where 2 < a < 3.2; adding a second alkali solution to the first treatment solution to obtain a second treatment solution with a pH of b, where 2.5 < b < 4; performing a solid-liquid separation treatment on the second treatment solution to obtain an impurity removal residue and a filtrate containing nickel, cobalt, and manganese; where the first alkali solution includes sodium ions and / or potassium ions.

[0005] Thus, in this application, by controlling the pH of the first treatment solution, and when the first alkali solution contains sodium ions, Fe in the nickel-cobalt-manganese mixed solution 3+ is converted into jarosite precipitate, and the jarosite precipitate can adsorb Al 3+ , thereby while removing Fe 3+ , improving the removal rate of Al 3+ ; when the first alkali solution contains potassium ions, Al in the nickel-cobalt-manganese mixed solution 3+ is converted into kalinite precipitate, and the kalinite precipitate can adsorb Fe 3+ , thereby while removing Al 3+ , improving the removal rate of Fe 3+ ; when the first alkali solution contains both sodium ions and potassium ions, Fe in the nickel-cobalt-manganese mixed solution 3+ is converted into jarosite precipitate, and the jarosite precipitate can adsorb Al 3+ , while at the same time Al 3+ will also be converted into kalinite, and the kalinite precipitate can adsorb Fe 3+ , thereby further improving Fe 3+ and Al 3+The removal rate is then achieved by controlling the pH of the second treatment liquid, and the iron hydroxide colloid and aluminum hydroxide colloid generated in the reaction system are transformed into iron hydroxide precipitates and aluminum hydroxide precipitates through the co-adsorption and co-precipitation characteristics of iron hydroxide precipitates and aluminum hydroxide precipitates; in the subsequent filtration process, large particle precipitates are effectively intercepted, while the penetration of fine colloidal particles is reduced, thereby improving the filtration rate and impurity removal efficiency.

[0006] In some embodiments, the a is 2.3-2.8. Thus, Fe 3+ and / or Al 3+ removal rate.

[0007] In some embodiments, b is 3.0-3.5. Thus, Fe 3+ and / or Al 3+ removal rate.

[0008] In some embodiments, the first alkali solution includes a first solute and a second solute, wherein the first solute includes at least one of sodium carbonate, sodium hydroxide, potassium hydroxide, and potassium carbonate; and the second solute includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide. Thus, by compounding the first solute and the second solute, the risk of local over-alkalinity in the reaction solution can be reduced, and the occurrence of precipitation reactions of cobalt ions and nickel ions caused by local over-alkalinity can be reduced, thereby effectively reducing the content of cobalt and nickel elements in the impurity removal slag, and achieving full recovery of valuable metals.

[0009] In some embodiments, the sum of the mass fractions of the first solute and the second solute in the first alkali solution is 15%-25%. 3+ Converted to yellow sodium ferroaluminate precipitate, and / or Al 3+ It is converted into yellow potassium aluminum alum precipitation; at the same time, it can reduce the probability of reaction between cobalt ions, nickel ions and hydroxide ions.

[0010] In some embodiments, the second alkali solution includes a third solute, and the third solute includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide. Thus, the first treatment solution and the second alkali solution continue to react, and the iron hydroxide colloid and aluminum hydroxide colloid with smaller particle size generated in the reaction system use the iron hydroxide precipitate and the aluminum hydroxide precipitate as crystal nuclei, and utilize the adsorption effect of the crystal nuclei to gradually agglomerate the iron hydroxide colloid and the aluminum hydroxide colloid, thereby forming the iron hydroxide precipitate and the aluminum hydroxide precipitate.

[0011] In some embodiments, the mass fraction of the third solute in the second alkali solution is 15%-25%, thereby converting the iron hydroxide colloid and aluminum hydroxide colloid in the first treatment solution into iron hydroxide precipitate and aluminum hydroxide precipitate, and reducing the probability of cobalt ions, nickel ions and hydroxide ions reacting.

[0012] In some embodiments, the sum of the concentrations of cobalt ions and nickel ions in the nickel-cobalt-manganese mixed solution is greater than or equal to 40 g / L. Thus, after effectively removing impurities from the nickel-cobalt-manganese mixed solution, high concentrations of nickel ions, cobalt ions, and manganese ions can be retained, thereby improving the recovery rate of valuable metals and obtaining nickel-cobalt-manganese products with better purity and quality.

[0013] In some embodiments, the impurity ions in the nickel-cobalt-manganese mixed solution include at least one of trivalent iron ions and trivalent aluminum ions.

[0014] In some embodiments, the reaction conditions for adding the first alkali solution to the nickel-cobalt-manganese mixed solution meet the following conditions: the reaction temperature is 80°C-90°C, and the reaction time is 1h-3h. Thus, selecting an appropriate reaction temperature and reaction time can accelerate the rate of the precipitation reaction, facilitate the rapid precipitation of iron and aluminum elements, reduce the loss of valuable metals, and thus improve the impurity removal efficiency.

[0015] In some embodiments, the reaction conditions for adding the second alkali solution to the first treatment solution meet the following conditions: the reaction temperature is 60°C-75°C, and the reaction time is 0.5h-1h. Therefore, by selecting an appropriate reaction temperature and reaction time, the rate of transformation of the iron hydroxide colloid and the aluminum hydroxide colloid into the iron hydroxide precipitate and the aluminum hydroxide precipitate can be accelerated, which is conducive to the rapid precipitation of the iron element and the aluminum element, thereby improving the impurity removal efficiency; at the same time, the energy consumption of the impurity removal process can be reduced.

[0016] In some embodiments, the step of performing solid-liquid separation on the second treatment liquid further includes: performing heat preservation treatment on the second treatment liquid, wherein the heat preservation temperature of the heat preservation treatment is 30°C-60°C, and the heat preservation time of the heat preservation treatment is 1h-3h. Thus, selecting appropriate heat preservation treatment conditions is conducive to further maturation and aggregation of iron hydroxide precipitates and aluminum hydroxide precipitates, increasing the particle size of the precipitates, thereby improving the filtration efficiency of the precipitates.

[0017] In some embodiments, the impurity-removing slag is subjected to a washing treatment, and the washing treatment includes a stirring washing treatment or a leaching washing treatment, thereby recovering nickel ions, cobalt ions, and manganese ions attached to the surface of the impurity-removing slag, thereby reducing the loss of valuable metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 It is a schematic diagram of the process flow of a method for removing impurities from a nickel-cobalt-manganese mixed solution in one embodiment of the present application. DETAILED DESCRIPTION

[0020] Hereinafter, the embodiment of the method for removing impurities from the nickel-cobalt-manganese mixed solution of the present application is specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0021] " Scope " disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be to include end values ​​or not include end values, and can be combined arbitrarily, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0022] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0023] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0024] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; unless otherwise specified, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0025] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. "First feature" and "second feature" may include one or more of the features.

[0026] In the description of the present application, "A and / or B" may include the case of A alone, the case of B alone, or any of the cases of A and B, where A and B are only used for examples and may be any technical feature connected by "and / or" in the present application.

[0027] In the process of recycling waste batteries, sulfuric acid is usually used as a leaching solution, which can transfer the metal elements in the positive electrode active material of the battery to the acid solution to obtain a metal recovery solution. The metal recovery solution of the present application is a nickel-cobalt-manganese mixed solution. The impurity elements in the nickel-cobalt-manganese mixed solution mainly include iron and aluminum. The iron and aluminum elements are in the form of free Fe 3+ and Al 3+ exists in the form of a nickel-cobalt-manganese mixed solution.

[0028] In the related art, free Fe 3+ and Al 3+ The precipitate is then filtered to obtain a pure nickel-cobalt-manganese mixed solution. For example, the neutralization hydrolysis method, the sodium iron alum method, the goethite method, and the hematite method. Although these four impurity removal methods can convert Fe 3+ and Al 3+ The colloids are converted into precipitates and then removed. However, these impurity removal methods all have their own limitations. Specifically, the iron hydroxide colloids and aluminum hydroxide colloids generated by the neutralization and hydrolysis method have high viscosity and small particle size, which easily lead to filtering difficulties and serious filtration problems during the filtration process. At the same time, the content of nickel and cobalt elements in the impurity removal residue is high, resulting in the loss of valuable metals. The working pH of the sodium iron alum method is in the range of 1.6-2.0, and the pH is too low, which makes it difficult to remove Al. 3+ , Al 3+ The removal efficiency is low; the goethite method requires Fe 3+ The concentration of Fe2O3 should not exceed 1g / L, and the generated iron hydroxide colloid has high viscosity, which is not conducive to filtration, resulting in Fe 3+The removal efficiency is low; the hematite method requires reaction under high temperature conditions (160℃-200℃), which places strict requirements on impurity removal equipment.

[0029] In the first aspect of the present application, the present application provides a method for removing impurities from a nickel-cobalt-manganese mixed solution, referring to Figure 1 , the method comprising:

[0030] S100: adding a first alkali solution to the nickel-cobalt-manganese mixed solution to obtain a first treatment solution.

[0031] The nickel-cobalt-manganese mixed solution used in the present application includes nickel, cobalt and manganese, and the nickel, cobalt and manganese elements are present in the nickel-cobalt-manganese mixed solution as free nickel ions, cobalt ions and manganese ions, respectively. In some embodiments, the sum of the concentrations of cobalt ions and nickel ions in the nickel-cobalt-manganese mixed solution is greater than or equal to 40 g / L. Thus, after effectively removing impurities in the nickel-cobalt-manganese mixed solution, high concentrations of nickel ions, cobalt ions and manganese ions can be retained, thereby improving the recovery rate of valuable metals and obtaining nickel-cobalt-manganese products of better purity and quality.

[0032] As an example, the sum of the concentrations of cobalt ions and nickel ions in the nickel-cobalt-manganese mixed solution includes but is not limited to 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L or 100 g / L.

[0033] The impurity elements of the nickel-cobalt-manganese mixed solution used in the present application mainly include at least one of iron and aluminum. In some embodiments, the iron element is in the form of free Fe 3+ The presence and / or free Al 3+ exist.

[0034] In some embodiments, Fe 3+ and Al 3+ The sum of the concentrations is 1g / L-15g / L. Thus, the impurity content from low to high can be covered, so that the impurity removal method of the present application can be applied to nickel-cobalt-manganese mixed solutions with different impurity contents, thereby improving the applicability and flexibility of the process.

[0035] As an example, Fe in a mixed solution of nickel, cobalt and manganese 3+ and Al 3+ The sum of the concentrations can be 1 g / L, 3 g / L, 5 g / L, 7 g / L, 9 g / L, 11 g / L, 13 g / L or 15 g / L.

[0036] In some embodiments, the first alkali solution includes sodium ions and / or potassium ions. Thus, when the first alkali solution contains sodium ions, Fe 3+ Transformed into yellow sodium ferroaluminate precipitate, yellow sodium ferroaluminate precipitate can adsorb Al3+ , so as to remove Fe 3+ while increasing the removal rate of Al 3+ . When the first lye contains potassium ions, Al in the nickel-cobalt-manganese mixed solution 3+ is converted into jarosite precipitate, and the jarosite precipitate can adsorb Fe 3+ , so as to remove Al 3+ while increasing the removal rate of Fe 3+ . When the first lye contains both sodium ions and potassium ions, Fe in the nickel-cobalt-manganese mixed solution 3+ is converted into schwertmannite precipitate, and the schwertmannite precipitate can adsorb Al 3+ , and at the same time, Al 3+ will also be converted into jarosite, and the jarosite precipitate can adsorb Fe 3+ , thereby further increasing the removal rates of Fe 3+ and Al 3+ .

[0037] In some embodiments, the first lye includes a first solute and a second solute. The first solute includes at least one of sodium carbonate, sodium hydroxide, potassium hydroxide, and potassium carbonate; the second solute includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide; the solute of the second alkaline solution includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide. The reaction of calcium carbonate, calcium hydroxide, or calcium oxide with hydrogen ions in the nickel-cobalt-manganese mixed solution can slowly release hydroxide ions, thereby reducing the risk of local over-alkalinity in the reaction solution. Thus, through the compounding of the first solute and the second solute, the occurrence of precipitation reactions of cobalt ions and nickel ions due to local over-alkalinity can be reduced, and further, the contents of cobalt elements and nickel elements in the impurity removal slag can be effectively reduced, realizing the full recovery of valuable metals.

[0038] In some embodiments, the sum of the mass fractions of the first solute and the second solute in the first lye is 15%-25%. Thus, selecting an appropriate concentration of the first lye helps Fe 3+ to be converted into schwertmannite precipitate, and / or Al 3+ to be converted into jarosite precipitate; at the same time, the probability of the reaction of cobalt ions and nickel ions with hydroxide ions can be reduced.

[0039] As an example, the sum of the mass fractions of the first solute and the second solute in the first lye can be 15%, 17%, 19%, 21%, 23%, or 25%.

[0040] In some embodiments, the pH of the first treatment solution is a, where 2 < a < 3.2. Thus, by controlling the pH of the first treatment solution, Fe 3+ is converted into schwertmannite precipitate, and the schwertmannite precipitate can adsorb Al 3+ , so as to remove Fe3+ At the same time, improve Al 3+ Removal rate of Al 3+ Transformed into yellow jarosite aluminum alum precipitate, yellow jarosite aluminum alum precipitate can adsorb Fe 3+ , thus removing Al 3+ At the same time, increasing Fe 3+ At the same time, under low pH conditions, the formation of iron hydroxide colloid and aluminum hydroxide colloid can be inhibited.

[0041] As examples, a includes, but is not limited to, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, or 3.2.

[0042] Preferably, the pH of the first treatment liquid is 2.3-2.8.

[0043] In some embodiments, the reaction conditions for adding the first alkali solution to the nickel-cobalt-manganese mixed solution meet the following conditions: the reaction temperature is 80° C.-90° C., and the reaction time is 1 h-3 h. Thus, selecting an appropriate reaction temperature and reaction time can accelerate the rate of the precipitation reaction, facilitate the rapid precipitation of iron and / or aluminum elements, reduce the loss of valuable metals, and thus improve the impurity removal efficiency.

[0044] As an example, the reaction temperature may be 80°C, 82°C, 84°C, 86°C, 88°C, or 90°C.

[0045] As an example, the reaction time may be 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h or 3 h.

[0046] S200: adding a second alkali solution to the first treatment solution to obtain a second treatment solution.

[0047] In some embodiments, the second alkali solution includes a third solute, and the third solute includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide. Thus, the first treatment solution and the second alkali solution continue to react, and the iron hydroxide colloid and aluminum hydroxide colloid with a smaller particle size produced in the reaction system are precipitated with iron hydroxide and aluminum hydroxide as crystal nuclei, and the adsorption of the crystal nuclei is used to gradually reunite iron hydroxide colloid and aluminum hydroxide colloid, and then form iron hydroxide precipitation and aluminum hydroxide precipitation. At the same time, calcium sulfate can also be used as a crystal nucleus to adsorb iron hydroxide colloid and aluminum hydroxide colloid. In addition, the third solute can also be used by other alkaline substances such as composite sodium carbonate, sodium hydroxide, potassium hydroxide, and potassium carbonate.

[0048] In some embodiments, the mass fraction of the third solute in the second lye is 15%-25%. Thereby, the iron hydroxide colloid and aluminum hydroxide colloid in the first treatment liquid are transformed into iron hydroxide precipitate and aluminum hydroxide precipitate, and at the same time, the probability of the reaction between cobalt ions, nickel ions and hydroxide ions can be reduced.

[0049] As an example, the mass fraction of the third solute in the second lye can be 15%, 17%, 19%, 21%, 23% or 25%.

[0050] In some embodiments, the reaction conditions for adding the second lye to the first treatment liquid satisfy the following conditions: the reaction temperature is 60°C - 75°C, and the reaction time is 0.5h - 1h. Thereby, by selecting appropriate reaction temperature and reaction time, the transformation rate of iron hydroxide colloid and aluminum hydroxide colloid into iron hydroxide precipitate and aluminum hydroxide precipitate can be accelerated, which helps the rapid precipitation of iron and aluminum elements, thus improving the impurity removal efficiency; at the same time, the energy consumption of the impurity removal process can be reduced.

[0051] As an example, the reaction temperature can be 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C or 75°C.

[0052] As an example, the reaction time can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h.

[0053] In some embodiments, the pH of the second treatment liquid is b, where 2.5 < b < 4. Thereby, the iron hydroxide colloid and aluminum hydroxide colloid generated in the reaction system are transformed into iron hydroxide precipitate and aluminum hydroxide precipitate, reducing the filtration difficulty and serious filtration through situation faced by the nickel-cobalt-manganese mixed solution during impurity removal, thus improving the filtration speed and the production line throughput.

[0054] As an example, b includes but is not limited to 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 or 4.

[0055] Preferably, the pH of the second treatment liquid is 3.0 - 3.5.

[0056] S300: Perform solid-liquid separation treatment on the second treatment liquid to obtain impurity removal slag and a filtrate containing nickel, cobalt and manganese.

[0057] In some embodiments, before the step of performing solid-liquid separation treatment on the second treatment liquid, the step further includes: performing heat preservation treatment on the second treatment liquid, the heat preservation temperature of the heat preservation treatment is 30°C-60°C, and the heat preservation time of the heat preservation treatment is 1h-3h. Therefore, selecting appropriate heat preservation treatment conditions is conducive to further maturation and aggregation of iron hydroxide precipitates and aluminum hydroxide precipitates, so that the particle size of the precipitates is increased, thereby improving the filtration efficiency of the precipitates.

[0058] As an example, the insulation temperature of the insulation treatment may be 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C.

[0059] As an example, the insulation time of the insulation treatment can be 1 h, 1.5 h, 2 h, 2.5 h or 3 h.

[0060] In some embodiments, the solid-liquid separation process includes any one of filtration, centrifugal separation, gravity sedimentation, centrifugal sedimentation, and membrane filtration. As an example, the filtration process separates the impurity-removed slag and the filtrate containing nickel, cobalt, and manganese in the second treatment liquid.

[0061] In some embodiments, the impurity-removing slag is subjected to a washing treatment, which includes a stirring washing treatment or a leaching washing treatment, thereby recovering nickel ions, cobalt ions, and manganese ions attached to the surface of the impurity-removing slag, thereby reducing the loss of valuable metals.

[0062] In some embodiments, the solution of the agitation and washing treatment includes a first solvent, the first solvent includes water, wherein the mass of the impurity removal slag is 20%-30% of the sum of the masses of the impurity removal slag and the first solvent. Thus, by controlling the ratio of the impurity removal slag and the first solvent, the first solvent can be fully contacted with the impurity removal slag to effectively remove the valuable metal ions attached to the surface of the impurity removal slag.

[0063] As an example, the mass of the clean slag may be 20%, 22%, 24%, 26%, 28% or 30% of the sum of the mass of the clean slag and the first solvent.

[0064] In some embodiments, the elution treatment solution includes a second solvent, the second solvent includes water, and the mass ratio of the impurity removal residue to the second solvent is 1:(2-4). By controlling the ratio of the impurity removal residue to the second solvent, the second solvent can be fully contacted with the impurity removal residue to effectively remove the valuable metal ions attached to the surface of the impurity removal residue.

[0065] As an example, the mass ratio of the impurity removal residue to the second solvent may be 1:2, 1:2.5, 1:3, 1:3.5 or 1:4.

[0066] In summary, the present invention prepares a first alkali solution containing sodium ions and / or potassium ions and controls the pH of the first treatment solution so that Fe 3+Transformed into yellow sodium ferroaluminate precipitate, yellow sodium ferroaluminate precipitate can adsorb Al 3+ , thereby removing Fe 3+ At the same time, improve Al 3+ Removal rate of Al 3+ Transformed into yellow jarosite aluminum alum precipitate, yellow jarosite aluminum alum precipitate can adsorb Fe 3+ , thus removing Al 3+ At the same time, increasing Fe 3+ removal rate; then the pH of the second treatment liquid is controlled, and the iron hydroxide colloid and aluminum hydroxide colloid generated in the reaction system are transformed into iron hydroxide precipitate and aluminum hydroxide precipitate through the co-adsorption and co-precipitation characteristics of iron hydroxide precipitate and aluminum hydroxide precipitate; in the subsequent filtration process, large particle precipitates are effectively intercepted, and the penetration phenomenon of fine colloidal particles is reduced, thereby improving the filtration rate and impurity removal efficiency.

[0067] As an example, the first alkali solution contains sodium ions, and the impurity ions include Fe 3+ and Al 3+ For example, the reaction equation involved in the impurity removal method is as follows:

[0068] (1) 3Fe 3+ +2SO 4 2- +6OH - +Na + =NaFe 3 (SO 4 ) 2 (OH) 6 (precipitation)

[0069] (2)Fe 3+ +3OH - =Fe(OH) 3 (precipitation)

[0070] (3)Fe 3+ +3OH - =Fe(OH) 3 (colloid)

[0071] (4) 3Fe 3+ +Al 3+ +2SO 4 2- +9OH - +Na + =NaFe 3 (SO 4 ) 2 (OH) 6 (precipitation)+Al(OH) 3 (precipitation)

[0072] (5)Al 3+ +3OH - =Al(OH) 3 (colloid)

[0073] (6)Al 3+ +3OH - =Al(OH) 3 (precipitation)

[0074] (7)Fe(OH) 3 (precipitation)+Fe(OH) 3 (colloid) = 2Fe(OH) 3 (precipitation)

[0075] (8)Al(OH) 3 (precipitation)+Al(OH) 3 (colloid) = 2Al(OH) 3 (precipitation)

[0076] The impurity removal method of the present application simplifies the production process, does not require new equipment, and is easy to operate on a production line; at the same time, the removal rate of iron ions in the present application can be increased to 99.5%, the removal rate of aluminum ions can be increased to 79.8%, the Co content in the impurity removal slag is less than 0.1%, the Ni content in the impurity removal slag is less than 0.1%, and the filtration rate can be increased to 2973.58 mL / min·m 2 , effectively reducing the pressure of impurity removal in the nickel-cobalt-manganese mixed solution and preventing the problem of iron and aluminum enrichment in the production line caused by filtration. In summary, the present application provides an efficient, economical and environmentally friendly Fe 3+ 、Al 3+ Removal methods have economic and environmental benefits.

[0077] The scheme of the present application is described below by specific examples. It should be noted that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in this area or the product instructions are used. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be obtained commercially.

[0078] Embodiment 1:

[0079] S100: taking a nickel-cobalt-manganese mixed solution, the nickel-cobalt-manganese mixed solution containing 73.89 g / L Ni element, 27.63 g / L Co element, 21.59 g / L Mn element, 3.74 g / L Fe element, and 1.62 g / L Al element;

[0080] A first alkali solution is prepared, the first alkali solution contains a first solute and a second solute, wherein the first solute is a mixture of sodium hydroxide and sodium carbonate, the second solute is calcium carbonate, and the sum of the mass fractions of the first solute and the second solute in the first alkali solution is 20%; and the solvent is water.

[0081] The nickel-cobalt-manganese mixed solution is heated to 90° C. by a water bath method, and then the first alkali solution is pumped into the nickel-cobalt-manganese mixed solution by a peristaltic pump, the reaction temperature is controlled to be 90° C., the reaction time is 1 h, and the reaction endpoint pH is controlled to be 2.5 to obtain a first treatment solution;

[0082] S200: preparing a second alkali solution, wherein the second alkali solution includes a third solute, wherein the third solute is a mixture of calcium carbonate, sodium hydroxide, and sodium carbonate, and the solvent is water; the mass fraction of the third solute in the second alkali solution is 20%;

[0083] Use a peristaltic pump to pump the second alkali solution into the first treatment solution, control the reaction temperature to 75° C., the reaction time to 0.5 h, and control the pH at the reaction endpoint to 3.2 to obtain a second treatment solution;

[0084] S300: The second treatment liquid is kept at 50°C for 2 hours and then filtered. The filtering method is fine filtering. Specifically, the second treatment liquid after the insulation is filtered using a material with a filtering accuracy of 5μm, and the fine filtering speed is recorded at the same time. After the filtering process is completed, the impurity removal residue and the filtrate containing nickel, cobalt and manganese are collected respectively; the impurity removal residue is washed with production water for 1 hour, wherein the mass of the impurity removal residue is 20% of the sum of the mass of the impurity removal residue and the production water.

[0085] The difference between Example 2 and Example 1 is that the first solute of the first alkali solution is sodium carbonate, and the second solute is calcium oxide; and the third solute of the second alkali solution is a mixture of calcium oxide and sodium carbonate.

[0086] The difference between Example 3 and Example 1 is that the first solute of the first alkali solution is sodium hydroxide, and the second solute is calcium carbonate; the third solute of the second alkali solution is a mixture of calcium carbonate and sodium hydroxide.

[0087] The difference between Example 4 and Example 1 is that the first solute of the first alkali solution is sodium carbonate, and the second solute is calcium hydroxide; the third solute of the second alkali solution is a mixture of calcium hydroxide and sodium carbonate.

[0088] The difference between Example 5 and Example 1 is that the third solute of the second alkali solution is calcium carbonate.

[0089] The difference between Example 6 and Example 1 is that the first solute of the first alkali solution is a mixture of potassium hydroxide and potassium carbonate, and the second solute is calcium carbonate; the third solute of the second alkali solution is a mixture of calcium carbonate, potassium hydroxide and potassium carbonate.

[0090] The difference between Example 7 and Example 1 is that the first alkali solution only includes the first solute, which is a mixture of sodium hydroxide and sodium carbonate; and the third solute of the second alkali solution is a mixture of sodium hydroxide and sodium carbonate.

[0091] The difference between Example 8 and Example 1 is that the reaction temperature in step S100 is 75°C.

[0092] The difference between Example 9 and Example 1 is that the reaction temperature in step S100 is 95°C.

[0093] The difference between Example 10 and Example 1 is that the reaction temperature in step S200 is 55°C.

[0094] The difference between Example 11 and Example 1 is that the reaction temperature in step S200 is 80°C.

[0095] The difference between Comparative Example 1 and Example 1 is that the first alkali solution only includes the second solute calcium carbonate, and the third solute of the second alkali solution is calcium carbonate.

[0096] The difference between Comparative Example 2 and Example 1 is that the pH at the end point of the reaction in step S100 is 3.2.

[0097] The difference between Comparative Example 3 and Example 1 is that the pH at the end point of the reaction in step S100 is 2.

[0098] The difference between Comparative Example 4 and Example 1 is that the pH at the end point of the reaction in step S200 is 2.5.

[0099] The difference between Comparative Example 5 and Example 1 is that the pH at the end point of the reaction in step S200 is 4.

[0100] After the impurity removal residue obtained in Example 1-11 and Comparative Example 1-5 was stirred and washed, the contents of Co and Ni in the impurity removal residue were tested; and the contents of Fe in the filtrate containing nickel, cobalt and manganese were tested. 3+ and Al 3+ The content.

[0101] According to the above test results, Fe 3+ Removal rate, Al 3+ Removal rate, Co content and Ni content in the impurity removal slag. Removal rate = (1-mass of metal elements in the solution after impurity removal / mass of metal elements in the solution before impurity removal) × 100%;

[0102] Co content in the impurity-removing slag = (1-Co mass in the impurity-removing slag / Co mass in the nickel-cobalt-manganese mixed solution before impurity removal) × 100%;

[0103] Ni content in impurity removal slag = (1-Ni mass in impurity removal slag / Ni mass in nickel-cobalt-manganese mixed solution before impurity removal) × 100%;

[0104] Co content, Ni content, Fe content in the slag 3+ Removal rate, Al 3+ The removal rate and fine filtration rate are shown in Table 1.

[0105] Table 1

[0106]

[0107]

[0108] As can be seen from Table 1, the first alkali solution used in Example 7 only includes the first solute, that is, only includes a mixture of sodium hydroxide and sodium carbonate. Since Example 7 does not contain calcium carbonate, calcium hydroxide, or calcium oxide, the reaction solution will be locally over-alkaline, resulting in precipitation reaction of cobalt ions and nickel ions, resulting in the Co content and Ni content in the impurity removal slag of Example 7 being higher than those of Examples 1-6.

[0109] In Examples 8-11, too high a reaction temperature will lead to increased energy consumption, and the evaporation of water in the reaction system is not conducive to the reaction; too low a reaction temperature will slow down the reaction and thus reduce the impurity removal efficiency. Example 1 can promote the formation of iron hydroxide precipitation and aluminum hydroxide precipitation by controlling the reaction temperature and reaction time at the same time. Therefore, the Fe 3+ and Al 3+ The removal rate is higher than that of Examples 8-11.

[0110] The first alkali solution used in Comparative Example 1 only includes the second solute, that is, only calcium carbonate. Since the first alkali solution of Comparative Example 1 does not contain Na + Therefore, Fe 3+ It cannot be converted into yellow sodium ferroaluminate precipitate and cannot further adsorb Al 3+ In Comparative Example 1, Fe is removed by adsorbing the generated iron hydroxide precipitate and aluminum hydroxide precipitate on the iron hydroxide colloid and aluminum hydroxide colloid. 3+ and Al 3+ , resulting in the content of unadsorbed iron hydroxide colloid and aluminum hydroxide colloid in the reaction system being too high, making it impossible to convert all the colloid into precipitation, resulting in Fe 3+ and Al 3+ The removal rate is lower than that of Example 1; at the same time, the content of ferric hydroxide colloid and aluminum hydroxide colloid is too high, resulting in serious filtration and the fine filtration rate data cannot be obtained.

[0111] The pH at the end of the reaction in step S100 in comparative example 2 is 3.2. The higher pH results in the generation of more iron hydroxide colloid and aluminum hydroxide colloid in the first treatment liquid, which increases the difficulty of subsequent precipitation and adsorption of colloid, resulting in Fe 3+ and Al 3+ The removal rate is lower than that of Example 1; at the same time, due to the high colloid content, the filtration is serious and the fine filtration rate data cannot be obtained.

[0112] In comparative example 3, the pH at the end of the reaction in step S100 is 2. The lower pH makes Fe 3+ The difficulty of converting into yellow sodium ferroaluminate precipitation increases, resulting in the adsorption of Al 3+ The amount of free Fe in the Ni-Co-Mn mixed solution is reduced; and the lower pH increases the free Fe 3+ and Al 3 + The difficulty of converting to precipitation or colloid leads to the free Fe in the first treatment solution. 3+ and Al 3+ The content is high, thus causing Fe 3+ and Al 3+ The removal rate is lower than that of Example 1, and even lower than that of Comparative Example 1; at the same time, due to the high colloid content, the filtration is serious and the fine filtration rate data cannot be obtained.

[0113] The pH at the end of the reaction in step S200 in comparative example 4 is 2.5. Too low a pH value increases the difficulty of converting the ferric hydroxide colloid and the aluminum hydroxide colloid into ferric hydroxide precipitate and the aluminum hydroxide precipitate, resulting in a high colloid content in the second treatment liquid, resulting in a lower filtration rate in comparative example 4 than in example 1. In addition, too low a pH value is not conducive to the Al 3+ The precipitation reaction results in the residual Al in the filtrate containing nickel, cobalt and manganese. 3+ Too high, which leads to Al 3+ The removal rate is too low.

[0114] In comparative example 5, the pH at the end of the reaction in step S200 is 4. A higher pH makes Fe 3+ and Al 3+ The precipitation reaction can occur well, and most of the iron and aluminum elements in the first treatment liquid are converted into iron hydroxide precipitate and aluminum hydroxide precipitate, so that the fine filtration speed of comparative example 5 is greater than that of embodiment 1. However, at the same time, the valuable metal elements cobalt and nickel in the second treatment liquid will also undergo precipitation reaction, resulting in the content of cobalt and nickel in the impurity removal slag being higher than that in embodiment 1, causing the loss of valuable metals.

[0115] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for removing impurities from a nickel-cobalt-manganese mixed solution, characterized in that: include: Add a first alkali solution to the nickel-cobalt-manganese mixed solution to obtain a first treatment solution with a pH of a, wherein 2 <a<3.2; Add a second alkali solution to the first treatment solution to obtain a second treatment solution with a pH of b, wherein 2.5 <b<4; The second treated liquid is subjected to a filtering treatment for solid-liquid separation to obtain a filtrate containing impurity-free residue and nickel, cobalt and manganese; Wherein, the first alkali solution includes sodium ions and / or potassium ions.

2. The method according to claim 1, characterized in that The a is 2.3-2.8; and / or the b is 3.0-3.

5.

3. The method according to claim 1 or 2, characterized in that: The first alkali solution includes a first solute and a second solute, wherein the first solute includes at least one of sodium carbonate, sodium hydroxide, potassium hydroxide, and potassium carbonate; and the second solute includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide.

4. The method according to claim 3, characterized in that The sum of the mass fractions of the first solute and the second solute in the first alkali solution is 15%-25%.

5. The method according to claim 1 or 2, characterized in that: The second alkali solution includes a third solute, and the third solute includes at least one of calcium carbonate, calcium hydroxide, and calcium oxide.

6. The method according to claim 5, characterized in that The mass fraction of the third solute in the second alkali solution is 15%-25%.

7. The method according to claim 1 or 2, characterized in that: The sum of the concentrations of cobalt ions and nickel ions in the nickel-cobalt-manganese mixed solution is greater than or equal to 40 g / L; and / or, The impurity ions in the nickel-cobalt-manganese mixed solution include at least one of trivalent iron ions and trivalent aluminum ions.

8. The method according to any one of claims 1 to 6, characterized in that: The reaction conditions of adding the first alkali solution to the nickel-cobalt-manganese mixed solution meet the following conditions: the reaction temperature is 80° C.-90° C., and the reaction time is 1 h-3 h; and / or, The reaction conditions for adding the second alkali solution to the first treatment solution meet the following conditions: the reaction temperature is 60° C.-75° C., and the reaction time is 0.5 h-1 h.

9. The method according to any one of claims 1 to 8, characterized in that: Before the step of performing solid-liquid separation treatment on the second treatment liquid, the step further includes: performing insulation treatment on the second treatment liquid, the insulation temperature of the insulation treatment is 30° C.-60° C., and the insulation time of the insulation treatment is 1 hour-3 hours.

10. The method according to any one of claims 1 to 9, characterized in that: Further including: The impurity-removed residue is subjected to a washing treatment, wherein the washing treatment includes an agitation washing treatment or a rinsing washing treatment.

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