Method for recovering aluminum in battery black powder

Abstract

The invention relates to the technical field of solid waste treatment, and provides a method for recycling aluminum in battery black powder. The recovery method comprises the following steps: carrying out roasting treatment on battery black powder and a first alkaline substance in an oxygen-containing atmosphere under the condition that the temperature is greater than or equal to 500 DEG C to obtain a roasted material; and the roasted material is placed in an alkaline solution to be subjected to leaching treatment, and aluminum-containing leaching liquid and dealuminized black powder are obtained. According to the method for recycling aluminum in the battery black powder, the aluminum element in the battery black powder can fully react with oxygen and the first alkaline substance through roasting treatment, the roasted material containing meta-aluminate is generated, and conversion of the aluminum element in the battery black powder from an aluminum elementary substance to an aluminum compound is achieved. And subsequently, when the roasted material is subjected to leaching treatment, as no aluminum elementary substance exists in the system, the risk that hydrogen is formed due to the reaction of the aluminum elementary substance and other substances is avoided, and the safety of the battery black powder during aluminum element recovery is effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resource comprehensive utilization, and particularly relates to a method for recovering aluminum in battery black powder. BACKGROUND

[0002] In the ternary battery recycling process, the conventional recycling process covers the steps of pretreatment, crushing, powdering, and screening, aiming to separate and extract the metal components such as nickel, cobalt, and lithium in the battery which have economic value, and finally output black or gray-black powder. However, due to the inherent defects of the current powdering and screening process, a certain amount of high-aluminum battery black powder will inevitably be produced, and the aluminum content of which is usually in the range of 4%-16%.

[0003] In the subsequent leaching process of the recycling process, the aluminum element in the high-aluminum battery black powder will react chemically and release a large amount of hydrogen gas. As a typical flammable and explosive gas, hydrogen gas greatly threatens the safety of production operations, and a slight mistake may cause serious safety accidents. Moreover, a large amount of aluminum elements leaching into the solution system greatly increases the pressure of the downstream impurity removal process, and puts forward higher requirements for impurity removal technology and equipment.

[0004] To solve this problem, some processes in the industry try to use liquid alkali for pre-leaching treatment. However, practice has proved that this method still cannot completely prevent the generation of hydrogen gas in the aluminum removal process, and cannot fundamentally guarantee the safety of production. This results in a large amount of high-aluminum battery black powder that cannot be properly treated and can only be stored, which not only occupies a large amount of valuable land, but also hides environmental pollution hazards. Therefore, developing a safe, efficient and large-scale industrialized process to realize the resource recycling of high-aluminum battery black powder has become a key problem to be solved in the ternary battery recycling industry. SUMMARY

[0005] The purpose of the present application is to provide a method for recovering aluminum in battery black powder, aiming to solve the safety problem caused by the generation of hydrogen gas in the battery black powder treatment process.

[0006] To achieve the above application purpose, the technical solution adopted by the present application is as follows:

[0007] The present application provides a method for recovering aluminum in battery black powder, comprising the following steps:

[0008] The battery black powder and the first alkaline substance are calcined under the condition of containing oxygen atmosphere and the temperature being greater than or equal to 500℃, to obtain calcined material;

[0009] The calcined material is placed in an alkaline solution for leaching treatment, to obtain aluminum-containing leaching solution and aluminum-removed black powder.

[0010] In some embodiments, the temperature of the calcination treatment is 500°C-1200°C; and / or, the time of the calcination treatment is 1h-3h.

[0011] In some embodiments, the temperature of the calcination treatment is 500°C-700°C, and the time is 1h-1.5h.

[0012] In some embodiments, the amount of the first alkaline substance added is 0.6-1.5 times the stoichiometric amount required for the formation of aluminate from aluminum in the battery black powder; and / or, the first alkaline substance comprises at least one of a carbonate, a bicarbonate.

[0013] In some embodiments, the first alkaline substance comprises at least one of a carbonate of an alkali metal, a bicarbonate of an alkali metal, a carbonate of an alkaline earth metal, a bicarbonate of an alkaline earth metal.

[0014] In some embodiments, the first alkaline substance comprises at least one of sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, calcium bicarbonate.

[0015] In some embodiments, the alkaline solution is a solution containing the second alkaline substance, and the mass ratio of the calcination material to the second alkaline substance contained in the alkaline solution is 1:(0.1-3).

[0016] In some embodiments, the alkaline solution at least satisfies one of the following conditions:

[0017] (1) the liquid-solid ratio of the alkaline solution to the calcination material is (10-30):1;

[0018] (2) the mass solubility of the second alkaline substance in the alkaline solution is 1wt%-10wt%;

[0019] (3) the second alkaline substance comprises at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide.

[0020] In some embodiments, the second alkaline substance comprises at least one of a hydroxide of an alkali metal, a hydroxide of an alkaline earth metal.

[0021] In some embodiments, the second alkaline substance comprises at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide.

[0022] In some embodiments, the conditions of the leaching treatment comprise a temperature of 40°C-95°C and a time of 0.5h-3h.

[0023] In some embodiments, in the oxygen-containing atmosphere, the volume percentage of oxygen is 21%-100%.

[0024] In some embodiments, the mass content of aluminum in the battery black powder is 4-16%; and / or, the battery black powder comprises at least one of lithium, nickel, cobalt, manganese, and iron.

[0025] In some embodiments, the roasting material is placed in an alkaline solution for leaching treatment to obtain an aluminum-containing leaching solution and a de-aluminum black powder, and the specific process is as follows:

[0026] The roasting material is placed in an alkaline solution for leaching treatment, and then solid-liquid separation is performed to obtain an aluminum-containing leaching solution and a de-aluminum black powder.

[0027] The first aspect of the present application provides a method for recovering aluminum from battery black powder, which roasts battery black powder and a first alkaline substance under specific conditions, which enables the aluminum in the battery black powder to fully react with oxygen and the first alkaline substance to generate roasting material containing meta-aluminate, thereby achieving efficient conversion of aluminum from elemental aluminum to aluminum compounds in the battery black powder. Subsequently, during leaching treatment of the roasting material, the content of elemental aluminum in the system is extremely low, or even zero, which significantly reduces the risk of hydrogen gas formation due to the reaction of elemental aluminum with other substances, effectively improving the safety of battery black powder during aluminum recovery. In addition, by optimizing the roasting temperature, the present application not only achieves efficient conversion of aluminum in the battery black powder, but also significantly reduces the cost of aluminum recovery, i.e., reduces the cost problem caused by excessively high temperature. Therefore, the present application not only improves the safety of the battery black powder treatment process, but also effectively solves the environmental pollution problem caused by long-term accumulation of battery black powder, thereby having significant environmental benefits and economic value. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 is a process flow diagram of the method for recovering aluminum from battery black powder provided by the embodiments of the present application. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects of the present application more clear, the following will further describe the present application with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0031] In the present application, the term "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0032] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or the like means any combination of the items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0033] It should be understood that in various embodiments of the present application, the size of the sequence number of the above processes does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0034] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0035] The weight of the related components mentioned in the specification of the embodiments of the present application can not only refer to the specific content of each component, but also represent the weight ratio relationship between each component. Therefore, as long as the content of the related components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass mentioned in the specification of the embodiments of the present application can be μg, mg, g, kg and other mass units commonly known in the chemical field.

[0036] The terms "first", "second" are only used for description purposes, to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features.

[0037] Noun explanation:

[0038] Battery black powder: after the waste lithium ion battery (including ternary lithium ion battery, lithium iron phosphate battery) is pretreated by crushing, sorting and the like, a black powder mixture containing valuable metals (such as lithium, nickel, cobalt and manganese) is obtained.

[0039] High-aluminum battery black powder: after the waste lithium ion battery (including ternary lithium ion battery, lithium iron phosphate battery) is pretreated by crushing, sorting and the like, a black powder mixture is obtained, in which the content of aluminum is much higher than that of the conventional lithium battery positive electrode waste, which is usually caused by the mixing of the positive electrode current collector (aluminum foil) or the aluminum shell assembly in the crushing and sorting process.

[0040] Solid content: refers to the percentage of the mass of solid substances contained in a liquid (such as a solution, slurry, suspension and the like) in the total system mass.

[0041] During the treatment of aluminum elements in battery black powder, alkali leaching or acid leaching is the mainstream process for recovering aluminum elements. However, the aluminum elements in the battery black powder are mostly in the form of elemental aluminum, which makes the elemental aluminum react with acid and alkali during the leaching process, continuously releasing hydrogen gas, directly leading to a substantial increase in safety risk in aluminum recovery treatment. Especially for high-aluminum battery black powder, the content of aluminum elements is higher, and the safety problem caused by hydrogen production during the recovery process is more serious. At present, some processes use neutralization and hydrolysis method to remove aluminum, but the depth of impurity removal is limited, and the high concentration of impurities greatly increases the pressure of impurity removal in the production line, resulting in high cost of impurity removal.

[0042] Based on this, the present application provides a method for recovering aluminum from battery black powder, which promotes the conversion of aluminum elements from elemental aluminum to compounds by using roasting, and optimizes the conditions of roasting treatment, such as temperature, to greatly reduce the cost problem caused by excessive temperature, and obtains a high-safety, low-cost aluminum recovery treatment method suitable for large-scale industrialization and popularization. The specific scheme is as follows.

[0043] In a first aspect, the embodiments of the present application provide a method for recovering aluminum from battery black powder, and the process flow is as shown in Figure 1 The method comprises the following steps:

[0044] Step S10, roasting the battery black powder and the first alkaline substance under an oxygen-containing atmosphere and at a temperature greater than or equal to 500°C to obtain a roasted material;

[0045] Step S20, placing the roasted material in an alkaline solution for leaching treatment to obtain an aluminum-containing leaching solution and a de-aluminum black powder.

[0046] The method for recovering aluminum from battery black powder provided in the first aspect of the embodiments of the present application first roasts high-aluminum black powder and a first alkaline substance under specific conditions to generate a roasted material containing meta-aluminate and aluminum oxide, and then uses an alkaline solution for leaching treatment to further convert the aluminum oxide in the roasted material into meta-aluminate, so as to finally obtain an aluminum-containing leaching solution mainly containing meta-aluminate and a dealuminized black powder containing trace aluminum compounds or completely removing aluminum elements. The method is suitable for recovering aluminum from battery black powder and high-aluminum battery black powder.

[0047] The reaction principle involved in the present application is shown below, which is described by taking sodium carbonate as the first alkaline substance and a sodium hydroxide solution as the alkaline solution as an example.

[0048] During the roasting process, on the one hand, elemental aluminum reacts with sodium carbonate and oxygen at high temperature to form sodium meta-aluminate, and on the other hand, elemental aluminum reacts with oxygen to form aluminum oxide, and the specific reaction process is shown in chemical equations (1) and (2).

[0049] 4Al + 2Na2CO3 + 3O2 → 4NaAlO2 + 2CO2 (1)

[0050] 4Al + 3O2 → 2Al2O3 (2)

[0051] During the leaching process, the aluminum oxide in the roasted material reacts with sodium hydroxide to generate sodium meta-aluminate, and after separation treatment, an aluminum-containing leaching solution mainly containing sodium meta-aluminate is obtained, and the specific reaction process is shown in chemical equation (3).

[0052] Al2O3 + 2NaOH → 2NaAlO2 + H2O (3)

[0053] Under the above roasting conditions, specifically including a specific temperature, the aluminum elements in the battery black powder can fully react with oxygen and the first alkaline substance to generate a roasted material containing meta-aluminate and aluminum oxide, thereby realizing effective conversion of the aluminum elements in the battery black powder from elemental aluminum to aluminum compounds. Based on this, during the subsequent leaching treatment of the roasted material, the risk of hydrogen gas generated by the reaction of elemental aluminum with other substances such as alkaline substances is less likely to occur, thereby effectively improving the safety of the battery black powder during the aluminum recovery process.

[0054] In addition, by optimizing the roasting treatment temperature, the present application can also greatly reduce the cost in the aluminum recovery process, i.e., reduce the cost problem caused by excessively high temperature. Therefore, the technical scheme of the present application not only effectively improves the safety during the battery black powder treatment process, but also takes into account the lower economic cost, and effectively solves the environmental pollution problem caused by long-term accumulation of battery black powder, so that it has significant environmental benefits and economic value.

[0055] In some embodiments, in step S10, the temperature of the roasting treatment is 500-1200°C.

[0056] Specifically, the temperature of the roasting treatment can be any one of 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C, 1200°C, or within a range formed by any two of them.

[0057] Within the above range, it is more advantageous for the aluminum element in the battery black powder to fully react with oxygen and the first alkaline substance to obtain a roasting material containing metaborate.

[0058] In some embodiments, in step S10, the time of the roasting treatment is 1-3h.

[0059] Specifically, the time of the roasting treatment can be any one of 1h, 1.5h, 2h, 2.5h, 3h, or within a range formed by any two of them.

[0060] Controlling the time of the roasting treatment within the above range can significantly promote the full reaction of the aluminum element in the battery black powder with oxygen and the first alkaline substance, thereby efficiently promoting the conversion of the aluminum element from an element to a compound, and obtaining a roasting material containing metaborate.

[0061] In some embodiments, in step S10, the mass content of the aluminum element in the battery black powder is 4-16%; and / or, the battery black powder includes at least one of lithium element, nickel element, cobalt element, manganese element, and iron element.

[0062] Specifically, the mass content of the aluminum element in the battery black powder can be any one of 4%, 5%, 6%, 7%, 8%, 10%, 12%, 13%, 14%, 15%, 16%, or within a range formed by any two of them.

[0063] Since the content of the aluminum element in the battery black powder is high, the specific value is as shown above, and the aluminum element is mostly in the form of an element, therefore, after the roasting treatment provided in the present application, efficient conversion of the aluminum element from an element to a compound can be achieved, and the safety problem caused by the reaction of aluminum element with other substances to produce hydrogen gas is reduced. Since the battery black powder also contains various valuable components, such as nickel element, cobalt element, manganese element, etc., the de-aluminum black powder needs to further remove the contained aluminum element to obtain high-purity valuable components, therefore, after the leaching treatment in the present application, the residual aluminum content in the de-aluminum black powder can be effectively reduced, the pressure of the further impurity removal process is greatly reduced, the economy and safety are taken into account, and it is more advantageous for industrialization promotion and application.

[0064] In some embodiments, in step S10, the temperature of the roasting treatment is 500-700°C, and the time is 1-1.5h.

[0065] Specifically, the temperature of the roasting treatment can be any one of 500℃, 550℃, 600℃, 650℃, 700℃ or within a range formed by any two of them.

[0066] Specifically, the time of the roasting treatment can be any one of 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, etc. or within a range formed by any two of them.

[0067] Under the above roasting treatment conditions, the aluminum element in the battery black powder can fully react with oxygen and the first alkaline substance to generate a roasting material containing metaborate and aluminum oxide, further reducing the economic cost of aluminum recovery treatment on the basis of efficient conversion of aluminum elements in the battery black powder from aluminum single element to aluminum compounds, and improving the universality and economic value of battery black powder aluminum recovery treatment.

[0068] In some embodiments, in step S10, the amount of the first alkaline substance added is 0.6-1.5 times the theoretical amount of the substance required for the aluminum in the battery black powder to generate metaborate.

[0069] Specifically, the amount of the first alkaline substance added is any one of 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1.0 times, 1.1 times, 1.2 times, etc. or within a range formed by any two of them of the theoretical amount of the substance required for the aluminum in the battery black powder to generate metaborate.

[0070] It can be understood that the theoretical amount of the substance required for the aluminum in the battery black powder to generate metaborate refers to the mass of the first alkaline substance required to achieve complete conversion of aluminum elements from single element to metaborate based on the stoichiometric ratio.

[0071] Within the above range, the aluminum element in the battery black powder can fully react with the first alkaline substance to achieve efficient conversion of aluminum elements from single element to compound.

[0072] In some embodiments, in step S10, the first alkaline substance includes at least one of a carbonate and a bicarbonate.

[0073] In some embodiments, in step S10, the first alkaline substance includes at least one of a carbonate of an alkali metal, a bicarbonate of an alkali metal, a carbonate of an alkaline earth metal, and a bicarbonate of an alkaline earth metal.

[0074] In some embodiments, the first alkaline substance includes at least one of sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, and calcium bicarbonate.

[0075] The first basic compounds can have a high-efficiency and directional reaction with aluminum elements in the battery black powder, promoting the full conversion of aluminum elements into metahydroxides. More importantly, during the entire aluminum recovery process, the compounds can maximize the risk of introducing impurities, effectively reducing the difficulty and production cost of further separation and purification of dealuminized materials.

[0076] In some embodiments, in step S10, the volume percentage of oxygen in the oxygen-containing atmosphere is 21%-100%.

[0077] Specifically, the volume percentage of oxygen can be any one of 21%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or within a range formed by any two thereof. As an example, the oxygen-containing atmosphere can be at least one of pure oxygen and air.

[0078] During the roasting process, oxygen has a dual role: first, oxygen can fully react with aluminum elements and the first basic substance to generate metahydroxides; second, oxygen can react with aluminum elements to convert them into aluminum oxide. Based on this, regulating the volume percentage of oxygen in the oxygen-containing atmosphere within the above range means that there is sufficient oxygen supply during the roasting process, which not only significantly improves the conversion efficiency of aluminum elements from elemental state to combined state, but also improves the completeness and thoroughness of the entire conversion process. In this way, when the subsequent leaching with an alkaline solution is performed, the risk of hydrogen generation due to the presence of elemental aluminum is effectively reduced.

[0079] In some embodiments, in step S20, the alkaline solution is a solution containing a second basic substance, and the mass ratio of the roasted material to the second basic substance contained in the alkaline solution is 1:(0.1-3).

[0080] Specifically, the mass ratio of the roasted material to the second basic substance contained in the alkaline solution is any one of 1:0.1, 1:0.5, 1:1, 1:2, 1:3, or within a range formed by any two thereof.

[0081] Within the above range, the aluminum oxide in the roasted material can fully react with the second basic substance, and the aluminum oxide in the roasted material is converted into metahydroxide as much as possible, thereby significantly reducing the aluminum content in the dealuminized material to reduce the difficulty of the subsequent impurity removal process.

[0082] The mass ratio of the roasted material to the second basic substance contained in the alkaline solution can be adjusted by adjusting any one or both of the liquid-solid ratio of the alkaline solution to the roasted material and the concentration of the second basic substance contained in the alkaline solution, so that the mass ratio of the roasted material to the second basic substance contained in the alkaline solution is within the above range. In this way, the aluminum oxide in the roasted material can fully react and be converted into metahydroxide.

[0083] In some embodiments, in step S20, the alkaline solution at least satisfies one of the following conditions: (1) the liquid-solid ratio of the alkaline solution to the calcined material is (10-30): 1; (2) the mass concentration of the second alkaline substance in the alkaline solution is 1wt%-10wt%; (3) the second alkaline substance comprises a hydroxide.

[0084] Specifically, the liquid-solid ratio of the alkaline solution to the calcined material can be any one of 10:1, 15:1, 20:1, 25:1, 30:1, or within the range formed by any two of them. It can be understood that the unit of the liquid-solid ratio in the present application is mL: g, or L: kg, for example, the liquid-solid ratio of 10:1 means that the liquid-solid ratio is 10 mL: 1 g, or 10 L: 1 kg.

[0085] Specifically, the mass concentration of the second alkaline substance in the alkaline substance can be any one of 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, or within the range formed by any two of them.

[0086] Specifically, the second alkaline substance comprises at least one of the corresponding hydroxide of an alkali metal and the corresponding hydroxide of an alkaline earth metal.

[0087] Specifically, the hydroxide comprises at least one of sodium hydroxide, potassium hydroxide, and calcium hydroxide.

[0088] In some embodiments, in step S20, the conditions of the leaching treatment include: the temperature is 40℃-95℃, and the time is 0.5h-3h.

[0089] Specifically, the temperature of the leaching treatment can be any one of 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 95℃, or within the range formed by any two of them; the time of the leaching treatment can be any one of 0.5h, 1h, 2h, 3h, or within the range formed by any two of them.

[0090] By controlling the temperature and time during the leaching treatment process, the alumina in the calcined material can be fully contacted and reacted with the second alkaline substance at a faster speed, promoting the conversion of alumina to metahalate, and reducing the aluminum content in the dealuminized material as much as possible, thereby reducing the pressure in the subsequent impurity removal process.

[0091] In some embodiments, in step S20, the dealuminized black powder contains aluminum elements, and the aluminum elements exist in the form of aluminum compounds.

[0092] The aluminum element in the battery black powder is converted into aluminum compounds such as aluminum oxide and metaaluminate through roasting treatment, and then leached with an alkaline solution to convert the aluminum oxide into metaaluminate as much as possible, thereby obtaining dealuminated black powder containing a trace amount of aluminum oxide.

[0093] In some embodiments, the roasted material is placed in an alkaline solution for leaching to obtain an aluminum-containing leachate and dealuminated black powder as follows:

[0094] The roasted material is placed in an alkaline solution for leaching treatment, and then the solid-liquid separation is carried out to obtain an aluminum-containing leaching solution and dealuminated black powder.

[0095] In some embodiments, the solid-liquid separation step is as follows:

[0096] The reaction liquid after leaching treatment is subjected to filter press separation to obtain aluminum-containing leaching liquid and dealuminated black powder.

[0097] After filter press separation, a filter residue and a filtrate are obtained, wherein the filtrate is an aluminum-containing leachate. The filter residue is washed and dried to form a dealuminated black powder. Specifically, the washing can be performed by at least one of agitation washing and rinsing. In some embodiments, the washing includes agitation washing and rinsing performed sequentially.

[0098] After solid-liquid separation, the aluminum-containing leachate obtained can be further recovered and processed using methods well known in the art to convert the metaaluminate in the aluminum-containing leachate into aluminum oxide. As an example, the aluminum oxide can be recovered using a Bayer process.

[0099] After solid-liquid separation, the resulting dealuminated black powder can be further processed to recover valuable elements, such as nickel, cobalt, and lithium, by methods well known in the art. For example, solvent extraction, chemical extraction, electrolysis, and the like can be used to recover the valuable elements in the dealuminated black powder.

[0100] The following describes the details in conjunction with specific embodiments.

[0101] Example 1

[0102] This embodiment provides a method for recovering aluminum from battery black powder, comprising the following steps:

[0103] Step 1: Provide 10g of battery black powder, including lithium oxide, nickel oxide, cobalt oxide, manganese oxide, iron oxide, and aluminum oxide, wherein the weight percentages of the metal elements are as follows:

[0104] Li: 2.74%, Ni: 10.53%, Co: 9.97%, Mn: 4.53%, Fe: 1.97%, Al: 7.96%, and the balance is carbon.

[0105] Step 2, mix 10 g of battery black powder and 1.872 g of sodium carbonate, and roast under the condition of 700℃ and oxygen for 1 h to obtain roasted material, wherein the theoretical amount of sodium carbonate required for the generation of sodium metaaluminate from aluminum in the battery black powder is 1.56 g, and the added amount of sodium carbonate is 1.2 times the theoretical amount of the substance required for the generation of sodium metaaluminate from aluminum in the battery black powder.

[0106] Step 3, provide a sodium hydroxide solution with a mass concentration of 2%, and add the roasted material into the sodium hydroxide solution according to a liquid-solid ratio of 20:1 (20 mL:1 g), and leach under the condition of 60℃ for 3 h to obtain reaction material.

[0107] Step 4, perform solid-liquid separation on the reaction material to obtain aluminum-containing leaching solution and dealuminized black powder, wherein the solid-liquid separation step is as follows:

[0108] Transport the reaction material into a filter press within 40 min, and filter under the condition of normal temperature and 0.6 Pa for 15 min to obtain filtrate and first filter residue, wherein the filtrate is the aluminum-containing leaching solution;

[0109] Use water to wash the first filter residue, mix and stir the water and the filter residue to form a mixed solution with a solid content of 25%, and wash for 1 h, and then filter (0.6 Pa, 15 min) to obtain second filter residue;

[0110] Use water to leach the second filter residue according to a liquid-solid ratio of 3:1 (mL:g), and obtain third filter residue, and dry the third filter residue under the condition of 100℃ to obtain dealuminized black powder.

[0111] Example 2

[0112] The difference between this embodiment and Example 1 is that the oxygen in Step 2 of Example 1 is replaced by air (oxygen volume percentage is 21%).

[0113] Example 3

[0114] The difference between this embodiment and Example 1 is that the added amount of sodium carbonate in Step 2 is different. The Step 2 is specifically as follows:

[0115] Step 2, mix 10 g of battery black powder and 1.56 g of sodium carbonate, and roast under the condition of 700℃ and oxygen for 1 h to obtain roasted material, wherein the added amount of sodium carbonate is 1.0 times the theoretical amount of the substance required for the generation of sodium metaaluminate from aluminum in the battery black powder.

[0116] Example 4

[0117] The embodiment provides a method for recovering aluminum in battery black powder, and the difference from the embodiment 1 is that the adding amount of sodium carbonate in step 2 is different. The step 2 is specifically as follows:

[0118] In step 2, 10g of battery black powder and 0.936g of sodium carbonate are mixed, oxygen is introduced, and roasting is carried out at 700 DEG C for 1h to obtain a roasting material, wherein the adding amount of sodium carbonate is 0.6 times of the theoretical amount of substance required for generating sodium metaaluminate from aluminum in the battery black powder.

[0119] Embodiment 5

[0120] The embodiment provides a method for recovering aluminum in battery black powder, and the difference from the embodiment 1 is that the temperature of roasting treatment in step 2 is different. The step 2 is specifically as follows:

[0121] In step 2, 10g of battery black powder and 1.872g of sodium carbonate are mixed, oxygen is introduced, and roasting is carried out at 1200 DEG C for 1h to obtain a roasting material, wherein the adding amount of sodium carbonate is 1.2 times of the theoretical amount of substance required for generating sodium metaaluminate from aluminum in the battery black powder.

[0122] Embodiment 6

[0123] The embodiment provides a method for recovering aluminum in battery black powder, and the difference from the embodiment 1 is that the temperature of roasting treatment in step 2 is different. The step 2 is specifically as follows:

[0124] In step 2, 10g of battery black powder and 1.872g of sodium carbonate are mixed, oxygen is introduced, and roasting is carried out at 500 DEG C for 1h to obtain a roasting material, wherein the adding amount of sodium carbonate is 1.2 times of the theoretical amount of substance required for generating sodium metaaluminate from aluminum in the battery black powder.

[0125] Embodiment 7

[0126] The embodiment provides a method for recovering aluminum in battery black powder, and the difference from the embodiment 1 is that the first alkaline substance in step 2 is different. The step 2 is specifically as follows:

[0127] In step 2, 10g of battery black powder and 1.77g of calcium carbonate are mixed, oxygen is introduced, and roasting is carried out at 700 DEG C for 1h to obtain a roasting material, wherein the theoretical amount of substance required for generating calcium metaaluminate from aluminum in the battery black powder is 1.475g, and the adding amount of calcium carbonate is 1.2 times of the theoretical amount of substance required for generating calcium metaaluminate from aluminum in the battery black powder.

[0128] Embodiment 8

[0129] The embodiment provides a method for recovering aluminum in battery black powder, and the difference from the embodiment 1 is that the temperature of roasting treatment in step 2 is different. The step 2 is specifically as follows:

[0130] Step 3, a sodium hydroxide solution with a mass concentration of 2% is provided, and the roasted material is added into the sodium hydroxide solution according to a liquid-solid ratio of 20:1 (20 mL:1 g), and is subjected to leaching treatment at a temperature of 40℃ for 3h to obtain a reaction material.

[0131] Example 9

[0132] This example provides a method for recovering aluminum in battery black powder, which is different from example 1 in that the first alkaline substance in step 2 is different, and the oxygen content is different. The step 2 is specifically:

[0133] Step 2, 10g of battery black powder and 1.77g of calcium carbonate are mixed, and air (oxygen content of 21%) is introduced to be roasted at a temperature of 700℃ for 1h to obtain a roasted material, wherein the addition amount of calcium carbonate is 1.2 times of the theoretical amount of substance required for the generation of calcium metaaluminate from aluminum in the battery black powder.

[0134] Example 10

[0135] This example provides a method for recovering aluminum in battery black powder, which is different from example 1 in that the addition amount of the first alkaline substance in step 2 is different. The step 2 is specifically:

[0136] Step 2, 10g of battery black powder and 0.624g of sodium carbonate are mixed, and oxygen is introduced to be roasted at a temperature of 700℃ for 3h to obtain a roasted material, wherein the addition amount of sodium carbonate is 0.4 times of the theoretical amount of substance required for the generation of sodium metaaluminate from aluminum in the battery black powder.

[0137] Example 11

[0138] This example provides a method for recovering aluminum in battery black powder, which is different from example 1 in that the temperature and time of roasting treatment in step 2 are different. The step 2 is specifically:

[0139] Step 2, 10g of battery black powder and 1.872g of sodium carbonate are mixed, and oxygen is introduced to be roasted at a temperature of 500℃ for 0.5h to obtain a roasted material, wherein the addition amount of sodium carbonate is 1.2 times of the theoretical amount of substance required for the generation of sodium metaaluminate from aluminum in the battery black powder.

[0140] Example 12

[0141] This example provides a method for recovering aluminum in battery black powder, which is different from example 1 in that the concentration of the sodium hydroxide solution in step 3 is different. The step 3 is specifically:

[0142] Step 3, a sodium hydroxide solution with a mass concentration of 0.5% is provided, and the roasted material is added into the sodium hydroxide solution according to a liquid-solid ratio of 20:1 (20 mL:1 g), and leaching treatment is performed at a temperature of 60°C for 3 h to obtain a reaction material.

[0143] Example 13

[0144] The comparative example provides a method for recovering aluminum in battery black powder, which is different from example 1 in that the liquid-solid ratio of the sodium hydroxide solution to the roasted material in step 3 is different. The step 3 is specifically as follows:

[0145] Step 3, a sodium hydroxide solution with a mass concentration of 2% is provided, and the roasted material is added into the sodium hydroxide solution according to a liquid-solid ratio of 10:1 (10 mL:1 g), and leaching treatment is performed at a temperature of 60°C for 3 h to obtain a reaction material.

[0146] Comparative Example 1

[0147] The comparative example provides a method for recovering aluminum in battery black powder, which is different from example 1 in that the temperature of the roasting treatment in step 2 is different. The step 2 is specifically as follows:

[0148] Step 2, 10 g of battery black powder and 1.872 g of sodium carbonate are mixed, and oxygen is introduced for roasting at a temperature of 400°C for 1 h to obtain a roasted material, wherein the addition amount of sodium carbonate is 1.2 times the theoretical amount required for the generation of sodium metaaluminate from aluminum in the battery black powder.

[0149] The performance parameters in the methods for recovering aluminum in battery black powder provided in examples 1-13 and comparative example 1, such as whether hydrogen is generated, the aluminum element removal rate, and the aluminum element content in the dealuminized black powder, are listed in Tables 1 and 2 as follows.

[0150] Table 1

[0151]

[0152]

[0153] As can be seen from Table 1, compared with comparative example 1, by using specific roasting conditions in the examples of the present application, efficient conversion of aluminum elements in battery black powder from aluminum single element to aluminum compounds is facilitated, which reduces the risk of hydrogen generation due to the reaction of aluminum single element with other substances in the subsequent leaching process, or even achieves zero hydrogen generation, effectively improving the safety of battery black powder in aluminum recovery treatment.

[0154] Table 2

[0155] Number Purification rate (%) Aluminum content in dealuminated black powder (%) Example 1 83.47％ 2.10％ Example 2 84.65％ 2.00％ Example 3 75.93％ 2.40％ Example 4 70.09％ 2.71％ Example 5 86.17％ 1.87％ Example 6 66.72％ 2.80％ Example 7 67.66％ 2.79％ Example 8 77.28％ 2.49％ Example 9 76.72％ 2.43％ Example 10 87.66％ 1.46％ Example 11 89.27％ 1.40％ Example 12 51.83％ 3.81％ Example 13 43.89％ 4.89％

[0156] In Table 2, the impurity removal rate can be calculated according to formula (I):

[0157]

[0158] In formula (I), W1 represents the mass content of aluminum in the aluminum-containing leaching solution in the battery black powder, and W2 represents the mass content of aluminum in the de-aluminum black powder.

[0159] The aluminum content in the aluminum-containing leaching solution and the aluminum content in the de-aluminum black powder can both be tested by the ICP (inductively coupled plasma) method.

[0160] As can be seen from Table 2, by adjusting the mass ratio of the calcined material to the second alkaline substance contained in the alkaline solution, such as the liquid-solid ratio of the alkaline solution and the calcined material, and the concentration of the alkaline solution, the conversion of aluminum oxide to metahydroxyapatite can be effectively promoted, thereby effectively reducing the residual aluminum content in the de-aluminum black powder and improving the aluminum element impurity removal rate.

[0161] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for recovering aluminum from battery black powder, characterized in that: The following steps are involved: calcining the battery black powder and the first alkaline substance in an oxygen-containing atmosphere at a temperature greater than or equal to 500° C. to obtain a calcined material; The roasted material is placed in an alkaline solution for leaching treatment to obtain an aluminum-containing leaching solution and dealuminated black powder.

2. The method for recovering aluminum from battery black powder according to claim 1, wherein: The temperature of the calcination treatment is 500° C.-1200° C.; and / or the time of the calcination treatment is 1 hour-3 hours.

3. The method for recovering aluminum from battery black powder according to claim 2, wherein: The calcination temperature is 500° C.-700° C., and the calcination time is 1 h-1.5 h.

4. The method for recovering aluminum from battery black powder according to claim 1, wherein: The amount of the first alkaline substance added is 0.6-1.5 times the theoretical amount of the substance required to generate metaaluminate from the aluminum in the battery black powder; and / or, The first alkaline substance includes at least one of carbonate and bicarbonate.

5. The method for recovering aluminum from battery black powder according to claim 4, wherein: The first alkaline substance includes at least one of carbonates corresponding to alkali metals, bicarbonates corresponding to alkali metals, carbonates corresponding to alkaline earth metals, and bicarbonates corresponding to alkaline earth metals.

6. The method for recovering aluminum from battery black powder according to claim 5, wherein: The first alkaline substance includes at least one of sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, and calcium bicarbonate.

7. The method for recovering aluminum from battery black powder according to claim 1, wherein: The alkaline solution is a solution containing a second alkaline substance, and the mass ratio of the calcined material to the second alkaline substance is 1:(0.1-3).

8. The method for recovering aluminum from battery black powder according to claim 7, wherein: The alkaline solution satisfies at least one of the following conditions: (1) The liquid-to-solid ratio of the alkaline solution to the calcined material is (10-30):1; (2) the mass solubility of the second alkaline substance in the alkaline solution is 1 wt% to 10 wt%; (3) The second alkaline substance includes a hydroxide.

9. The method for recovering aluminum from battery black powder according to claim 8, wherein: The second alkaline substance includes at least one of a hydroxide corresponding to an alkali metal and a hydroxide corresponding to an alkaline earth metal.

10. The method for recovering aluminum from battery black powder according to claim 9, wherein: The second alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, and calcium hydroxide.

11. The method for recovering aluminum from battery black powder according to claim 1, wherein: The leaching treatment conditions include: temperature of 40° C.-95° C., and time of 0.5 h-3 h.

12. The method for recovering aluminum from battery black powder according to claim 1, wherein: In the oxygen-containing atmosphere, the volume percentage of oxygen is 21%-100%.

13. The method for recovering aluminum from battery black powder according to any one of claims 1 to 12, characterized in that: The mass content of aluminum in the battery black powder is 4%-16%; and / or, The battery black powder includes at least one of lithium, nickel, cobalt, manganese and iron.

14. The method for recovering aluminum from battery black powder according to any one of claims 1 to 12, characterized in that: The specific process of placing the roasted material in an alkaline solution for leaching to obtain aluminum-containing leachate and dealuminated black powder is as follows: The roasted material is placed in an alkaline solution for leaching treatment, and then solid-liquid separation is performed to obtain aluminum-containing leaching solution and dealuminated black powder.

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