Comprehensive recycling method of lithium-rich aluminum acid leaching solution, lithium adsorption material and application

Abstract

The invention provides a recovery method of a lithium-rich aluminum acid leaching solution. The recovery method comprises the following steps: S1, providing the lithium-rich aluminum acid leaching solution with the pH value of 3-3.5; s2, extracting lithium from the lithium-rich aluminum acid leaching liquid obtained in the step S1 by using an adsorbent, then carrying out solid-liquid separation to obtain adsorption tail liquid and a lithium-rich adsorbent, and carrying out first concentration treatment on the adsorption tail liquid to obtain an aluminum source solution; s3, carrying out desorption lithium removal on the lithium-rich adsorbent in the step S2 to obtain a qualified desorption solution, and sequentially carrying out second concentration treatment and impurity removal treatment on the qualified desorption solution to obtain a first lithium-rich solution; and S4, mixing the first lithium-rich solution in the step S3, the aluminum source solution in the step S2 and the alkali solution, and carrying out a co-precipitation reaction to obtain the lithium adsorption material. According to the method, high-value comprehensive recycling of the lithium-rich aluminum leaching solution is achieved, and a new thought and method are provided for recycling lithium, aluminum, nickel, cobalt and manganese in waste saggars in the battery material industry.

Description

Technical Field

[0001] The present invention belongs to the fields of hydrometallurgy, lithium extraction technology, and metal element recovery, and particularly relates to a comprehensive recovery and utilization method for a lithium-rich aluminum acid leaching solution, a lithium adsorption material, and an application thereof. Background Art

[0002] Currently, the commercially available lithium-ion batteries mainly use lithium cobaltate, lithium manganate, lithium iron phosphate, and ternary cathode materials, and are mainly applied in the fields of 3C, power batteries, and energy storage. In the production process of lithium-ion batteries, the sintering process is the most core and important process. During the sintering process, the sagger, as the carrier of the mixed material of the cathode material precursor and the lithium source, plays a very important auxiliary role in the production process. The main materials of the sagger include cordierite, mullite, and alumina. However, during the sintering process, the lithium source (such as lithium carbonate) will react with the sagger. Under the action of adverse side reactions such as the erosion of lithium-containing compounds, the sagger will be scrapped after being used a certain number of times. However, the scrapped sagger contains valuable metals such as lithium and aluminum with high grades. Direct scrapping will cause waste of resources, and at the same time, the scrapping does not meet the environmental protection requirements. Therefore, it is necessary to recover and process the residual materials of the sagger. The waste sagger can be divided into three layers in total: the upper layer is attached with a relatively thin layer of black powder, which is the material that has not been cleaned up after roasting, and the main component is lithium nickel cobalt manganese oxide, accounting for 0.5%-1.5%; the middle sandwich layer is the main area where lithium exists, which is formed by the reaction of the roasted material and the sagger, and the main component is lithium meta-aluminate, accounting for 8.5%-10.5%; the lower layer is the sagger itself, and the main components are aluminum oxide, magnesium aluminum silicate, etc., accounting for 88%-91%.

[0003] At the present stage, the relatively common process flow is to first use strong acid leaching, obtain a lithium-containing and aluminum-containing leaching solution, then add alkali to precipitate aluminum, and finally deeply precipitate lithium. However, the defect of this process is that the loss of lithium entrained in the aluminum precipitation stage and the lithium precipitation stage is relatively large, and the lithium loss in the whole process reaches 50%, resulting in waste of lithium resources and no economic benefits. At present, there is also lithium extraction for the lithium-containing acid leaching solution, but the organic extractant used in the extraction process is harmful to the human body, and the post-treatment is relatively troublesome, increasing the environmental protection pressure. Therefore, a method with high lithium recovery rate, environmental protection and economy is needed to comprehensively recover and utilize the waste sagger leaching solution with high value. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. For this purpose, the present invention provides a comprehensive recovery and utilization method for a lithium-rich aluminum acid leaching solution, a lithium adsorption material, and an application thereof, which can prepare lithium carbonate products and doped aluminum-based lithium adsorption materials, realizing the high-value comprehensive recovery and utilization of the lithium-rich aluminum acid leaching solution, and providing new ideas and methods for the battery material industry to recover lithium, aluminum, and nickel cobalt manganese from waste saggers.

[0005] According to a first aspect of the present invention, a method for recovering a lithium-rich aluminic acid leaching solution is provided, comprising the following steps:

[0006] S1: Provide a lithium-rich aluminic acid leaching solution with a pH of 3 to 3.5;

[0007] S2: Use an adsorbent to extract lithium from the lithium-rich aluminic acid leaching solution in step S1, then perform solid-liquid separation to obtain an adsorption tail solution and a lithium-rich adsorbent, and perform a first concentration treatment on the adsorption tail solution to obtain an aluminum source solution;

[0008] S3: Perform desorption and lithium removal on the lithium-rich adsorbent in step S2 to obtain a qualified desorption solution, and perform a second concentration treatment and impurity removal treatment on the qualified desorption solution in sequence to obtain a first lithium-rich solution;

[0009] S4: Mix the first lithium-rich solution in step S3, the aluminum source solution in step S2, and an alkali solution to perform a coprecipitation reaction to obtain a lithium adsorption material.

[0010] In some embodiments, the lithium-rich aluminic acid leaching solution is prepared by acid leaching, filtering, and adjusting the pH of a lithium-containing waste crucible.

[0011] The lithium-rich aluminic acid leaching solution in the present invention can be obtained by acid leaching, filtering, and adjusting the value of a lithium-containing waste crucible. It is preferably acid-leached with hydrochloric acid having a concentration of 1 to 10 mol / L to obtain an acid leaching solution with a pH of 0.5 to 2.6. The filtering method for the acid leaching solution is one of bag filtration, sand filtration, microfiltration, and ultrafiltration, preferably bag filtration. The filtering precision is 50 to 100 μm, and this range can achieve the best filtering efficiency and filtering effect to remove solid suspended matters in the acid leaching solution. The pH value of the filtered acid leaching solution is adjusted with an alkali solution to obtain the lithium-rich aluminic acid leaching solution of the present invention. The alkali solution is preferably ammonia water (NH3·H2O) with a concentration of 0.5 to 10 mol / L.

[0012] In some embodiments, in step S1, the lithium-rich aluminic acid leaching solution contains elements Li, Ni, Co, Mn, and Al, wherein the content of Li is 2 to 4 wt%, the content of Ni is 0.05 to 0.3 wt%, the content of Co is 0.01 to 0.1 wt%, the content of Mn is 0.01 to 0.1 wt%, and the content of Al is 5 to 12 wt%.

[0013] In some embodiments, in step S2, the adsorbent is an aluminum-based lithium adsorbent; and / or, during the lithium extraction process, the flow rate of the lithium-rich aluminic acid leaching solution is 1 to 2 BV / h, where BV is the packed volume of the adsorbent.

[0014] In some preferred embodiments, the adsorbent is an aluminum-based lithium adsorbent doped with nickel, cobalt, and manganese.

[0015] It is a more appropriate solution to use an adsorbent to selectively extract lithium from the leaching solution of waste lithium-containing crucibles. However, since the pH of the leaching solution of waste lithium-containing crucibles is extremely low (≤2.6), it is impossible to directly use conventional lithium adsorbents to extract lithium under such strong acidic conditions. Conventional lithium adsorbents include aluminum-based lithium adsorbents, manganese-based lithium ion sieves, and titanium-based lithium ion sieves. Under strong acidic conditions, there may be dissolution loss of aluminum in the aluminum-based adsorbent, while manganese-based and titanium-based lithium ion sieves need to be under alkaline conditions to selectively extract lithium. Therefore, in the present invention, the selection of the type of lithium adsorbent is particularly crucial. Since the manganese-based adsorbent has poor chemical stability and cannot adsorb lithium ions under strong acidic environments, and acid solution desorption is likely to cause the collapse of its structure, resulting in the dissolution of manganese ions and polluting the qualified desorption solution, reducing the service life, and the large amount of acid used for desorption will also increase the environmental protection pressure. The titanium-based adsorbent has poor adsorption kinetics under acidic conditions, affecting the lithium extraction efficiency, and at the same time, the use of a large amount of acid during the delithiation process will also cause structural damage and cannot be restored.

[0016] The present invention preferably uses an aluminum-based lithium adsorbent [LiCl·mAl(OH)3·nH2O] for lithium extraction. The aluminum-based adsorbent can selectively adsorb lithium in an environment with a pH of 3 to 10 and has good stability. The pH of the lithium-rich aluminum acid leaching solution provided by the present invention is 3 to 3.5. Under this pH condition, it can not only meet the stable operation requirements of the aluminum-based lithium adsorbent, maintain the stable structure of the adsorbent, but also will not cause aluminum precipitation and lithium loss due to pH adjustment. At the same time, nickel, cobalt, manganese elements and aluminum elements in the adsorption tail liquid can enter the subsequent preparation process section of lithium adsorption materials together to prepare a new type of aluminum-based lithium adsorbent doped with nickel, cobalt, and manganese, and this adsorbent has a higher adsorption capacity. The principle is that aluminum chloride doped with nickel, cobalt, and manganese reacts with lithium chloride as the lithium source under alkaline conditions to undergo a coprecipitation reaction to form an aluminum-based lithium adsorbent [X·LiCl·mAl(OH)3·nH2O] doped with nickel, cobalt, and manganese, where X is a mixture of Ni, Co, and Mn; the doping of nickel, cobalt, and manganese optimizes the pore structure, increases the effective lithium adsorption sites, and thus improves the adsorption / desorption capacity. The above-mentioned doped aluminum-based lithium adsorbent can be recycled to the lithium extraction process section, improving the overall lithium recovery rate, increasing the lithium production capacity, and realizing the recycling of nickel, cobalt, and manganese. At the same time, the aluminum-based lithium adsorbent can be regenerated by a simple method and still maintain a high lithium adsorption efficiency after being regenerated repeatedly for many times.

[0017] In some embodiments, in step S2, the content of Li in the adsorption tail liquid is 0.01 to 0.05 wt%, the content of Ni is 0.05 to 0.3 wt%, the content of Co is 0.01 to 0.1 wt%, the content of Mn is 0.01 to 0.1 wt%, and the content of Al is 5 to 12 wt%.

[0018] In some embodiments, the pH of the adsorption tail liquid is 2.5 to 3.5.

[0019] In some embodiments, in step S2, the first concentration treatment is one of MVR evaporation concentration, low-temperature evaporation concentration, rotary evaporation concentration, and multi-effect evaporation concentration; and / or, the concentration multiple of the first concentration treatment is 5 to 7.

[0020] In some embodiments, in step S3, the flow rate of the analytical agent for lithium deintercalation is 2 to 4 BV / h.

[0021] In some preferred embodiments, the analytical agent is fresh water. Fresh water is used for lithium deintercalation in the present invention, which can be groundwater or surface water with a conductivity less than 100 μS / cm, distilled water, or RO pure water.

[0022] In some embodiments, in step S3, the content of Li in the qualified analytical solution is 0.4 to 0.8 wt%, and the content of Al is 0.1 to 0.5 wt%; and / or, the second concentration treatment is at least one of reverse osmosis membrane concentration or electrodialysis membrane concentration, and the impurity removal treatment is to remove aluminum using a chelating cation exchange resin.

[0023] In some preferred embodiments, the concentration multiple of the second concentration treatment is 9 to 11.

[0024] In some preferred embodiments, the chelating cation exchange resin is iminodiacetic acid type resin or ethylenediaminetetraacetic acid type resin.

[0025] In some embodiments, in step S3, the content of Li in the first lithium-rich solution is 6 - 8 wt%, and the content of Al is ≤ 0.005 wt%.

[0026] In some embodiments, step S3 further includes: performing a third concentration treatment on the first lithium-rich solution to obtain a second lithium-rich solution, and performing lithium precipitation on the second lithium-rich solution to obtain lithium carbonate. In the present invention, a conventional precipitating agent is used for lithium precipitation on the second lithium-rich solution, and the precipitating agent can preferably be sodium carbonate. After lithium precipitation, centrifugation, washing, and drying, a battery-grade lithium carbonate product with a purity of ≥ 99.5% can be obtained.

[0027] In some preferred embodiments, the third concentration treatment is at least one of electrodialysis concentration or evaporation concentration.

[0028] In some preferred embodiments, the concentration multiple of the third concentration treatment is 3 to 5.

[0029] In some preferred embodiments, the content of Li in the second lithium-rich solution is 20 - 25 wt%, and the content of Al is ≤ 0.005 wt%.

[0030] In some embodiments, in step S4, the lye is at least one of ammonia water, sodium hydroxide, sodium carbonate or potassium hydroxide; and / or, the concentration of the lye is 1-10 mol / L.

[0031] In some embodiments, in step S4, the steps of the coprecipitation reaction include: mixing and heating the first lithium-rich solution and the aluminum source solution with stirring, dropping the lye to adjust the end point pH to 6-7.5, and then keeping warm and standing for 0.5-1 h to obtain a lithium adsorption material.

[0032] In some preferred embodiments, the mixing is carried out according to a molar ratio of Li:Al = 0.6-1.0 of lithium in the first lithium-rich solution to aluminum in the aluminum source solution.

[0033] In some preferred embodiments, the heating temperature is 60-85 °C; and / or, the stirring speed is 100-200 r / min.

[0034] In some preferred embodiments, step S4 further includes: washing the lithium adsorption material and then performing spray drying to obtain a doped aluminum-based lithium adsorbent. The doped aluminum-based lithium adsorbent prepared by the present invention can be recycled to step S2 as an adsorbent to selectively extract lithium from the lithium-rich aluminum acid leaching solution. The adsorption capacity of the doped aluminum-based lithium adsorbent is higher than that of the undoped aluminum-based lithium adsorbent, which can further improve the lithium recovery rate of the process.

[0035] In some preferred embodiments, the washing is water washing.

[0036] According to the second aspect of the present invention, a lithium adsorption material is proposed, which is prepared by the method described in the first aspect of the present invention. The lithium adsorption material is doped with Ni, Co, and Mn, wherein the content of Ni is 0.05-0.3 wt%, the content of Co is 0.01-0.1 wt%, and the content of Mn is 0.01-0.1 wt%.

[0037] In some embodiments, the adsorption capacity of the lithium adsorption material is 4.2-4.6 g / L.

[0038] According to the third aspect of the present invention, an application of the method described in the first aspect of the present invention or the lithium adsorption material described in the second aspect in the treatment of lithium-containing waste crucibles is proposed. The lithium adsorption material prepared by the present invention can be recycled to the lithium extraction section to further increase the overall lithium recovery rate to more than 88%.

[0039] According to an embodiment of the present invention, it has at least the following beneficial effects:

[0040] 1. The present invention provides a new method for recycling rich lithium-aluminum acid leaching solution. Through the pre-treatment of adjusting the value, the pH is adjusted to the stable operation range of the aluminum-based lithium adsorbent, so that the preferred lithium adsorbent can be used to selectively extract lithium from the rich lithium-aluminum acid leaching solution; then through desorption and lithium removal, a qualified lithium-containing desorption solution is obtained, and after concentration and impurity removal, the first rich lithium solution is obtained. The first rich lithium solution and the concentrated solution of the adsorption tail liquid containing nickel, cobalt and manganese (aluminum source solution) are prepared into an aluminum-based lithium adsorbent through value adjustment, coprecipitation and spray drying.

[0041] 2. Further concentrating the above-mentioned first rich lithium solution, battery-grade lithium carbonate products can be directly obtained after lithium precipitation, centrifugation, washing and drying, realizing the comprehensive recycling of rich lithium-aluminum acid leaching solution.

[0042] 3. The optimized process of the present invention gets rid of the large amount of lithium loss caused by the conventional alkali-adding aluminum precipitation process, the environmental protection pressure brought by the conventional extraction lithium extraction, and the limitation that the conventional lithium adsorbent cannot directly adsorb and extract lithium, realizing a lithium recovery rate of more than 85%, an aluminum recovery rate of more than 90% and a nickel, cobalt and manganese recovery rate of more than 95%. Finally, battery-grade lithium carbonate products and aluminum-based lithium adsorbents are obtained, which is a high-value and economically feasible comprehensive recycling method. The process of this method is simple, green and environmentally friendly, only introducing alkali solution, precipitant and pure water, greatly reducing the operation cost and having good economic benefits; among them, the adsorption lithium extraction process has incomparable environmental protection advantages. This method also innovatively combines the lithium-rich solution for lithium extraction with the aluminum-rich adsorption tail liquid containing nickel, cobalt and manganese to synthesize a new type of aluminum-based adsorbent doped with nickel, cobalt and manganese, with the adsorption performance improved by more than 10%, which can be used in the front-end adsorption section to further increase the overall lithium recovery rate to more than 88%. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The following further describes the present invention with reference to the drawings and embodiments, where:

[0044] Figure 1 is the process flow chart of Embodiment 1 of the present invention;

[0045] Figure 2 is the SEM image of the aluminum-based lithium adsorbent doped with nickel, cobalt and manganese prepared in Embodiment 1 of the present invention magnified 5000 times;

[0046] Figure 3 is the SEM image of the aluminum-based lithium adsorbent doped with nickel, cobalt and manganese prepared in Embodiment 1 of the present invention magnified 2500 times;

[0047] Figure 4 is the comparison diagram of the XRD pattern of the aluminum-based lithium adsorbent doped with nickel, cobalt and manganese prepared in Embodiment 1 of the present invention and the standard card of LiCl·2Al(OH)3·xH2O; DETAILED DESCRIPTION OF THE INVENTION

[0048] The concept of the present invention and the technical effects produced will be clearly and completely described below in conjunction with the embodiments to fully understand the purpose, features, and effects of the present invention.

[0049] Unless otherwise specified, the raw materials, reagents, or devices used in the following embodiments can be obtained from conventional commercial channels or can be obtained by existing known methods. Among them, the commercial aluminum-based lithium adsorbent has the chemical formula LiCl·2Al(OH)3·xH2O; the iminodiacetic acid-type resin is a conventional commercially available product with the chemical formula R-[-CH2-N-(CH2COOH)2]; the lithium-containing waste sagger leaching solution is obtained by the following method: 200 g of waste sagger is leached with 10 mol / L hydrochloric acid for 2 hours to obtain 500 mL of acid leaching solution, which is obtained after bag filtration. Among them, the filtration accuracy of Examples 1 and 2 is 50 μm, and the filtration accuracy of Example 3 is 100 μm.

[0050] Example 1

[0051] This example provides a method for comprehensive recovery and utilization of a lithium-containing waste sagger leaching solution, as Figure 1 shown, specifically including the following steps:

[0052] (1): Add ammonia water (NH3·H2O) with a concentration of 3 mol / L to the lithium-containing waste sagger leaching solution to adjust the pH value to 3 to obtain a pretreatment solution.

[0053] (2): Use a commercial aluminum-based lithium adsorbent to selectively extract lithium from the pretreatment solution. The flow rate during the adsorption process is 1 BV / h, and the running time is 3 h to obtain an aluminum-containing lithium-depleted adsorption tail liquid and an adsorption-saturated adsorbent; the tail liquid is evaporated and concentrated with a rotary evaporator with a concentration multiple of 5 to obtain a concentrated liquid, that is, an aluminum source solution.

[0054] (3): Use RO pure water to desorb and delithiate the adsorption-saturated adsorbent. The flow rate during the desorption process is 2 BV / h, and the running time is 4 h to obtain a lithium-containing desorption qualified solution.

[0055] (4): The obtained desorption qualified solution is concentrated by a reverse osmosis membrane (recovery rate 90%) and the aluminum is removed by an iminodiacetic acid-type resin (200 mL) (feed flow rate 2 BV / h) to obtain a first lithium-rich liquid. Take a part of the first lithium-rich liquid and continue to concentrate it 2 times by electrodialysis (maintaining the membrane pair voltage at 0.3 - 0.5 V, current at 2 - 3 A, and temperature at 25 - 35 °C, and adjusting the pH of the dilute chamber to about 8 - 11 by adding NaOH) and then concentrate it 2 times by a rotary evaporator (temperature 95 °C, rotation speed 30 rpm) to obtain a second lithium-rich liquid.

[0056] (5): Add sodium carbonate to the second lithium-rich solution obtained in step (4) for lithium precipitation. The molar ratio of lithium to sodium carbonate in the second lithium-rich solution is 0.77, and the temperature is maintained at 80 °C. After centrifugation, washing, and drying, lithium carbonate products with a purity of 99.5% are obtained.

[0057] (6): Mix the concentrated solution of nickel-cobalt-manganese adsorption tail liquid (aluminum source solution) obtained in step (2) and the first lithium-rich solution obtained in step (4). The mixing ratio is based on the molar ratio of lithium in the first lithium-rich solution to aluminum in the concentrated solution of nickel-cobalt-manganese adsorption tail liquid, Li:Al = 0.6. Stir while heating, and simultaneously dropwise add 3 mol / L sodium hydroxide solution for coprecipitation reaction. Maintain the temperature at 65 °C. When the pH reaches 6, stop stirring to end the reaction, maintain 65 °C, and let it stand for 30 minutes; wash the precipitate at the bottom with RO pure water, and then obtain nickel-cobalt-manganese-doped aluminum-based lithium adsorbent through a spray drying device. Its SEM image is as Figure 2 、 Figure 3 shown, presenting spherical-like particles with a particle size of 5 - 10 μm.

[0058] (7): Conduct single-column performance tests on the newly prepared nickel-cobalt-manganese-doped aluminum-based lithium adsorbent and the conventional aluminum-based lithium adsorbent. The test results are shown in Table 2. The adsorption capacity of the newly doped lithium adsorbent is 4.5 g / L, which is 12.5% higher than that of the conventional lithium adsorbent. Repeating the above process with the newly prepared aluminum-based lithium adsorbent, the overall lithium recovery rate is increased from 80% to 88%, and the aluminum recovery rate is increased from 90% to 92%.

[0059] The lithium adsorption and extraction data of Example 1 are shown in Table 1.

[0060] Table 1 Lithium Adsorption and Extraction Data

[0061]

[0062] Table 2 Comparison of Lithium and Aluminum Recovery Rates and Adsorbent Performance

[0063] Name Adsorption capacity (g / L) Lithium recovery rate (%) Aluminum recovery rate (%) Newly doped aluminum-based adsorbent 4.5 88 92 Commercial aluminum-based adsorbent 4.0 80 90

[0064] Among them, the calculation method of the adsorption capacity is Q = V0(C0 - C) / V. In the formula, V0 is the volume of the adsorption pretreatment solution, L, C0 and C are the ionic concentrations of the pretreatment solution before and after adsorption, g / L; V is the amount of adsorbent added, L. The calculation method of the lithium recovery rate is M = (lithium recovery amount / lithium content in the waste) × 100%; the calculation method of the aluminum recovery rate is N = (aluminum recovery amount / aluminum content in the waste) × 100%.

[0065] Example 2

[0066] This example provides a method for comprehensive recovery and utilization of a lithium-containing waste crucible leaching solution, which specifically includes the following steps:

[0067] (1): Add ammonia water (NH₃·H₂O) with a concentration of 3.2 mol / L dropwise to the leaching solution of lithium-containing waste crucibles, adjust the pH value to 3.2, and obtain a pretreatment solution.

[0068] (2): Use an aluminum-based lithium adsorbent to selectively extract lithium from the pretreatment solution. The flow rate during the adsorption process is 1.5 BV / h, and the running time is 2 h to obtain an aluminum-containing lithium-depleted adsorption tail liquid and an adsorbent saturated with adsorption; evaporate and concentrate the tail liquid with a rotary evaporator, and the concentration multiple is 5 to obtain a concentrated solution, that is, an aluminum source solution.

[0069] (3): Use RO pure water to desorb and remove lithium from the adsorbent saturated with adsorption. The flow rate during the desorption process is 2.5 BV / h, and the running time is 3.2 h to obtain a qualified lithium-containing desorption solution.

[0070] (4): Concentrate the obtained qualified desorption solution by reverse osmosis membrane (recovery rate 90%), and remove aluminum with an iminodiacetic acid type resin (200 mL) (feed flow rate 2 BV / h) to obtain a first lithium-rich solution; take a part of the first lithium-rich solution and continue to concentrate it 2 times by electrodialysis (maintaining the membrane pair voltage at 0.3 - 0.5 V, current 2 - 3 A, temperature 25 - 35 °C, and adjusting the pH of the dilute chamber to about 8 - 11 by adding NaOH) and then concentrate it 2 times with a rotary evaporator (temperature 95 °C, rotation speed 30 rpm) to obtain a second lithium-rich solution.

[0071] (5): Add sodium carbonate to the second lithium-rich solution obtained in step (4) for lithium precipitation. The molar ratio of lithium to sodium carbonate in the second lithium-rich solution is 0.80, and the temperature is maintained at 80 °C. After centrifugation, washing, and drying, a lithium carbonate product with a purity of 99.6% is obtained.

[0072] (6): Mix the concentrated solution of the nickel-cobalt-manganese-containing adsorption tail liquid (aluminum source solution) obtained in step (2) and the first lithium-rich solution obtained in step (4). The mixing ratio is based on the molar ratio of lithium in the first lithium-rich solution to aluminum in the concentrated solution of the nickel-cobalt-manganese-containing adsorption tail liquid, Li:Al = 0.65. Stir while heating, and at the same time, dropwise add a 3 mol / L sodium hydroxide solution for coprecipitation reaction. Keep the temperature at 65 °C. When the pH reaches 6, stop stirring and keep the temperature at 65 °C for 30 minutes; wash the precipitate at the bottom with RO pure water, and then obtain a nickel-cobalt-manganese-doped aluminum-based lithium adsorbent through a spray drying device.

[0073] (7): Conduct a single-column performance test on the newly prepared nickel-cobalt-manganese-doped aluminum-based lithium adsorbent and the conventional aluminum-based lithium adsorbent. The test results are shown in Table 4. The adsorption capacity of the newly doped lithium adsorbent is 4.4 g / L, which is 12% higher than that of the conventional lithium adsorbent. Repeat the above process using the newly prepared aluminum-based lithium adsorbent, and the overall lithium recovery rate is increased from 83% to 90%, and the aluminum recovery rate is increased from 91% to 93%.

[0074] The lithium adsorption data of Example 2 are shown in Table 3.

[0075] Table 3 Lithium adsorption data

[0076]

[0077]

[0078] Table 4 Comparison of lithium and aluminum recovery rates and adsorbent performance

[0079] Name Adsorption capacity (g / L) Lithium recovery rate (%) Aluminum recovery rate (%) Newly doped aluminum-based adsorbent 4.40 90 93 Commercial aluminum-based adsorbent 3.93 83 91

[0080] Example 3

[0081] This example provides a method for comprehensive recovery and utilization of leaching solution from lithium-containing waste crucibles, which specifically includes the following steps:

[0082] (1): Add ammonia water (NH3·H2O) with a concentration of 3.3 mol / L to the leaching solution of lithium-containing waste crucibles, adjust the pH value to 3.3, and obtain a pretreatment solution.

[0083] (2): Use an aluminum-based lithium adsorbent to selectively extract lithium from the pretreatment solution. The flow rate during the adsorption process is 2 BV / h, and the running time is 1.5 h, to obtain an aluminum-rich and lithium-poor adsorption tail liquid and an adsorbent saturated with adsorption; evaporate and concentrate the tail liquid with a rotary evaporator, and the concentration multiple is 5, to obtain a concentrated liquid, that is, an aluminum source solution.

[0084] (3): Use RO pure water to desorb and de-lithiate the adsorbent saturated with adsorption. The flow rate during the desorption process is 3 BV / h, and the running time is 2.67 h, to obtain a qualified lithium-containing desorption solution.

[0085] (4): Concentrate the obtained qualified desorption solution by reverse osmosis membrane (recovery rate 90%), and remove aluminum with iminodiacetic acid type resin (200 mL) (feed flow rate 2 BV / h) to obtain a first lithium-rich liquid; take a part of the first lithium-rich liquid and continue to concentrate it 2 times by electrodialysis (maintaining the conditions of membrane pair voltage of 0.3 - 0.5 V, current of 2 - 3 A, and temperature of 25 - 35 °C, and adjusting the pH of the dilute chamber to about 8 - 11 by adding NaOH) and then concentrate it 2 times with a rotary evaporator (temperature 95 °C, rotation speed 30 rpm) to obtain a second lithium-rich liquid.

[0086] (5): Add sodium carbonate to the second lithium-rich liquid obtained in step (4) for lithium precipitation, where the molar ratio of lithium to sodium carbonate in the second lithium-rich liquid is 0.85, and the temperature is maintained at 80 °C. After centrifugation, washing, and drying, lithium carbonate products with a purity of 99.5% are obtained.

[0087] (6): Mix the nickel-cobalt-manganese-containing adsorption tail liquid concentrate (aluminum source solution) obtained in step (2) with the first lithium-rich liquid obtained in step (4). The mixing ratio is based on the molar ratio of lithium in the first lithium-rich liquid to aluminum in the nickel-cobalt-manganese-containing adsorption tail liquid concentrate, Li:Al = 0.67. Stir while heating, and simultaneously dropwise add 3 mol / L sodium hydroxide solution for coprecipitation reaction. Keep the temperature at 65 °C. When the pH reaches 6, stop stirring to end the reaction, keep at 65 °C, and let it stand for 30 minutes. Wash the precipitate at the bottom with RO pure water, and then obtain the nickel-cobalt-manganese-doped aluminum-based lithium adsorbent through a spray drying device.

[0088] (7): Conduct single-column performance tests on the newly prepared nickel-cobalt-manganese-doped aluminum-based lithium adsorbent and the conventional aluminum-based lithium adsorbent. The test results are shown in Table 6. The adsorption capacity of the newly doped lithium adsorbent is 4.55 g / L, which is 11% higher than that of the conventional lithium adsorbent. Repeat the above process using the newly prepared aluminum-based lithium adsorbent. The overall lithium recovery rate increases from 82% to 92%, and the aluminum recovery rate increases from 90.5% to 95%.

[0089] The lithium adsorption and extraction data of Example 3 are shown in Table 5.

[0090] Table 5 Lithium Adsorption and Extraction Data

[0091]

[0092] Table 6 Comparison of Lithium and Aluminum Recovery Rates and Adsorbent Performance

[0093] Name Adsorption capacity (g / L) Lithium recovery rate (%) Aluminum recovery rate (%) Newly doped aluminum-based adsorbent 4.55 92 95 Commercial aluminum-based adsorbent 4.1 82 90.5

[0094] Comparative Example 1

[0095] This comparative example provides a method for recycling the lithium-containing waste crucible leaching solution, which specifically includes the following steps:

[0096] (1): Take 500 mL of the same lithium-containing waste crucible leaching solution as in Example 3, add sodium hydroxide with a concentration of 3 mol / L to adjust the pH value to 6 for primary aluminum precipitation. After passing through a plate and frame filter press, obtain aluminum slag and a primary filtrate;

[0097] (2): Add 0.15 L of 3 mol / L sodium carbonate to the primary filtrate for secondary aluminum precipitation. After passing through a plate and frame filter press, obtain aluminum slag and a secondary filtrate.

[0098] (3): Add 0.1 L of 3 mol / L sodium carbonate to the secondary filtrate to precipitate lithium carbonate. Keep the temperature at 85 °C, and obtain 99.5% lithium carbonate product through centrifugation, washing, and drying.

[0099] (4): The lithium and aluminum yields of this conventional process were compared with those of the process in Example 3, and the results are shown in Table 7. It can be seen that the optimized lithium adsorption process has high lithium and aluminum yields, especially when using the newly prepared doped aluminum-based adsorbent.

[0100] Table 7 Comparison of lithium and aluminum recovery rates of different processes

[0101]

[0102] The present invention adopts new process means. After pre-treating the lithium-containing leaching solution of waste crucibles, the preferred lithium adsorbent can be directly used for selective lithium extraction. After obtaining the qualified eluate, impurity removal and concentration are carried out to obtain a lithium-rich solution. A part of the lithium-rich solution is further concentrated and then lithium precipitation is carried out to prepare battery-grade lithium carbonate products; another part of the lithium-rich solution is mixed and adjusted with the adsorption tail solution containing aluminum, nickel, cobalt and manganese to prepare a by-product of doped aluminum-based lithium adsorbent with better adsorption performance. The doped aluminum-based lithium adsorbent by-product is doped with Ni, Co, and Mn, where the content of Ni is 0.05-0.3 wt%, the content of Co is 0.01-0.1 wt%, and the content of Mn is 0.01-0.1 wt%. After returning to the front-end adsorption process, the lithium yield can be further improved. At the same time, this optimized process can recover more than 85% of lithium, more than 90% of aluminum, and more than 95% of nickel, cobalt and manganese. The calculation method of the nickel, cobalt and manganese recovery rate is Q = (the amount of recovered nickel, cobalt and manganese / the amount of nickel, cobalt and manganese in the waste) × 100%. The amount of recovered nickel, cobalt and manganese is the amount of nickel, cobalt and manganese in the waste minus the amount of nickel, cobalt and manganese in the washing and supernatant of the precipitate. While the conventional direct precipitation of aluminum and lithium from the leaching solution only recovers 50% of lithium and 70% of aluminum. After the process optimization, the operating cost is lower, with good economic benefits and being more environmentally friendly.

[0103] The above has made a detailed description of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art to which the present invention pertains, various changes can be made without departing from the purpose of the present invention. In addition, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. A method for recovering lithium-rich aluminum acid leaching solution, characterized in that: The following steps are involved: S1: providing a lithium-rich aluminum acid leaching solution with a pH of 3 to 3.5; S2: extracting lithium from the lithium-rich aluminum acid leaching solution in step S1 with an adsorbent, and then performing solid-liquid separation to obtain an adsorption tail liquid and a lithium-rich adsorbent, and performing a first concentration treatment on the adsorption tail liquid to obtain an aluminum source solution; S3: performing delithiation on the lithium-rich adsorbent described in step S2 to obtain a qualified solution, and performing a second concentration treatment and an impurity removal treatment on the qualified solution to obtain a first lithium-rich solution; S4: The first lithium-rich solution described in step S3, the aluminum source solution described in step S2 and the alkaline solution are mixed to perform a co-precipitation reaction to obtain a lithium adsorption material.

2. The method according to claim 1, characterized in that: In step S1, the lithium-rich aluminum acid leaching solution contains Li, Ni, Co, Mn, and Al elements, wherein the content of Li is 2-4wt%, the content of Ni is 0.05-0.3wt%, the content of Co is 0.01-0.1wt%, the content of Mn is 0.01-0.1wt%, and the content of Al is 5-12wt%.

3. The method according to claim 1, characterized in that: In step S2, the adsorbent is an aluminum-based lithium adsorbent; and / or, the flow rate of the lithium-rich aluminum acid leaching solution during the lithium extraction process is 1 to 2 BV / h, where BV is the filling volume of the adsorbent.

4. The method according to claim 1, characterized in that In step S2, the content of Li in the adsorption tail liquid is 0.01-0.05wt%, the content of Ni is 0.05-0.3wt%, the content of Co is 0.01-0.1wt%, the content of Mn is 0.01-0.1wt%, and the content of Al is 5-12wt%.

5. The method according to claim 1, characterized in that In step S2, the first concentration treatment is one of MVR evaporation concentration, low-temperature evaporation concentration, rotary evaporation concentration, and multi-effect evaporation concentration; and / or the concentration multiple of the first concentration treatment is 5 to 7.

6. The method according to claim 1, characterized in that In step S3, the content of Li in the qualified solution is 0.4-0.8wt%, and the content of Al is 0.1-0.5wt%; and / or, the second concentration treatment is at least one of reverse osmosis membrane or electrodialysis membrane concentration; the impurity removal treatment is aluminum removal using a chelating cation exchange resin.

7. The method according to claim 1, characterized in that Step S3 also includes: performing a third concentration process on the first lithium-rich solution to obtain a second lithium-rich solution, and precipitating lithium on the second lithium-rich solution to obtain lithium carbonate.

8. A lithium adsorption material prepared by the method according to any one of claims 1 to 7, characterized in that: The lithium adsorption material is doped with Ni, Co and Mn, wherein the content of Ni is 0.05-0.3wt%, the content of Co is 0.01-0.1wt%, and the content of Mn is 0.01-0.1wt%.

9. The lithium adsorption material according to claim 8, characterized in that The adsorption capacity of the lithium adsorption material is 4.2-4.6 g / L.

10. Use of the method according to any one of claims 1 to 7 or the lithium adsorption material according to any one of claims 8 to 9 in the treatment of waste saggers containing lithium.

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