A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste.

Abstract

This application belongs to the field of renewable resource recycling technology, and particularly relates to a method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste. This application provides a method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste by leaching the waste with sulfuric acid and hydrogen peroxide to obtain lanthanum- and strontium-rich leaching residue and manganese- and cobalt-containing leaching solution. The leaching residue is then leached a second time with hydrochloric acid to obtain lanthanum-containing leaching solution and strontium sulfate leaching residue. Alkali solution is added to the lanthanum-containing leaching solution to generate lanthanum hydroxide. Subsequently, sodium salts such as sodium sulfate are added to the manganese- and cobalt-containing leaching solution for a double salt reaction to obtain sodium sulfate lanthanum double salt and a mixed filtrate of manganese and cobalt. The mixed filtrate of manganese and cobalt is then subjected to extraction, washing, back-extraction, and calcination steps to obtain manganese oxide and cobalt oxide. This method realizes the recovery of valuable metals such as lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste, solving the technical problem of the lack of existing methods for recovering lanthanum, strontium, manganese, and cobalt.

Description

Technical Field

[0001] This application belongs to the field of renewable resource recycling technology, and in particular relates to a method for separately recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste. Background Technology

[0002] Currently, lanthanum strontium manganese cobalt composite oxide (LSM / MCO) is used as a protective coating material for Fe-Cr alloy connectors in solid-state fuel cells (SOFCs). The LSM / MCO coating can improve Cr poisoning and high-temperature conductivity of Fe-Cr alloys under high-temperature operating conditions in solid-state fuel cells, which is beneficial to the stable operation of solid-state fuel cells.

[0003] When preparing a lanthanum-strontium-manganese-cobalt composite oxide protective coating on the surface of Fe-Cr alloy connectors using a spraying process, lanthanum-strontium-manganese-cobalt waste is generated. At the same time, some Fe-Cr alloy connectors fail quality inspection and are defective products, which also generate lanthanum-strontium-manganese-cobalt waste. If the waste is discarded directly, it may cause environmental pollution and waste valuable metal resources. Therefore, it is necessary to recycle valuable metal resources such as lanthanum, strontium, manganese, and cobalt from the lanthanum-strontium-manganese-cobalt waste.

[0004] Nickel-cobalt-manganese materials are widely used as ternary cathode materials for lithium batteries in energy storage devices, power batteries, and new energy vehicles. With the development of new energy technologies, there is a lot of research on the recovery of cobalt and manganese from waste, but there is a lack of research on the recovery of lanthanum and strontium. Cobalt, manganese, lanthanum, and strontium have different properties, and the recovery technologies for cobalt and manganese cannot be directly used for the recovery of lanthanum and strontium. Therefore, it is necessary to develop a suitable method to utilize cobalt, manganese, lanthanum, and strontium in waste as resources. Summary of the Invention

[0005] In view of this, this application provides a method for separately recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste, in order to solve the technical problem of the lack of recovery methods for lanthanum, strontium, manganese and cobalt in the prior art.

[0006] The first aspect of this application provides a method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste, the method comprising the steps of:

[0007] Step S1: The lanthanum, strontium, manganese and cobalt waste is leached once in a mixed solution of sulfuric acid and hydrogen peroxide to obtain leachate and leaching residue;

[0008] Step S2: The leaching residue is placed in hydrochloric acid solution for a second leaching to obtain lanthanum-containing leaching solution and strontium sulfate leaching residue;

[0009] Step S3: Add an alkaline reagent to the lanthanum-containing leachate to carry out the first precipitation reaction, then filter to obtain lanthanum hydroxide precipitate;

[0010] Step S4: Add sodium sulfate to the leachate to carry out a double salt reaction, then filter to obtain sodium sulfate lanthanum double salt precipitate and manganese-cobalt mixed filtrate;

[0011] Step S5: Add the first acidic phosphorus-containing organic extractant to the manganese-cobalt mixed filtrate for the first extraction to obtain a manganese-rich organic phase and a cobalt-rich aqueous phase.

[0012] Step S6: After adding an acid solution to the manganese-rich organic phase for the first washing and the first back-extraction, the manganese-rich aqueous phase is calcined to obtain manganese oxide.

[0013] Step S7: Add a second acidic phosphorus-containing organic extractant to the cobalt-rich aqueous phase for a second extraction to obtain a cobalt-rich organic phase;

[0014] Step S8: After adding acid solution to the cobalt-rich organic phase for a second washing and a second back-extraction, a cobalt-rich aqueous phase is obtained.

[0015] Step S9: After the sodium bicarbonate solution in the cobalt-rich aqueous phase undergoes a second precipitation reaction, it is filtered, and the precipitate is obtained by calcination and filtration.

[0016] Preferably, after step S2, the method further includes the step of: placing the strontium sulfate leaching residue in a sodium carbonate solution for carbonation to obtain strontium carbonate solid.

[0017] Preferably, after step S3, the method further includes the step of calcining the lanthanum hydroxide precipitate to obtain lanthanum oxide.

[0018] Preferably, in step S1, the concentration of sulfuric acid used in the single leaching process is 50 g / L to 300 g / L, and the concentration of hydrogen peroxide is 40 to 60%.

[0019] Preferably, in step S1, during the single leaching process, the stirring speed is 200~400 rpm, the temperature is 60~100℃, and the time is 2~6 hours.

[0020] Preferably, in step S2, the concentration of the hydrochloric acid solution used in the secondary leaching process is 2~6 mol / L, and the liquid-solid ratio of the hydrochloric acid solution to the leaching residue is 2~8:1.

[0021] Preferably, in step S2, during the secondary leaching process, the stirring speed is 200~400 rpm, the temperature is 60~100℃, and the time is 1~3h.

[0022] Preferably, in step S3, the alkaline reagent used in the first precipitation reaction is sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium bicarbonate, or ammonia.

[0023] Preferably, in step S3, the first precipitation reaction process is as follows: under the conditions of a temperature of 60~70℃ and a pH of 10~14, the mixture is stirred for 0.5~2h and aged for 0.2~1h.

[0024] Preferably, in step S4, the volume-to-mass ratio of the leachate to sodium sulfate used in the double salt reaction is 100:10~20.

[0025] Preferably, in step S4, the pH is 3-5, the temperature is 60-100℃, and the time is 0.5-2h during the double salt reaction.

[0026] Preferably, in step S5, the first acidic phosphorus-containing organic extractant used in the first extraction process is a mixture of saponified acidic phosphorus-containing extractant and kerosene.

[0027] Preferably, in step S5, during the first extraction process, the volume ratio of the first acidic phosphorus-containing organic extractant to the manganese-cobalt mixed filtrate is 3~5:1, the mixing time for extraction is 3~10 min, and the settling time is 20~60 min.

[0028] Preferably, in step S7, the second acidic phosphorus-containing organic extractant used in the second extraction process is a mixture of saponified acidic phosphorus-containing extractant and kerosene.

[0029] Preferably, in step S7, during the second extraction process, the volume ratio of the first acidic phosphorus-containing organic extractant to the cobalt-rich aqueous phase is 3~5:1, the mixing time of the extraction is 3~10 min, and the standing time is 20~60 min.

[0030] Preferably, in step S5 or S7, the acidic phosphorus-containing extractant is at least one of P204, P507, and C272;

[0031] In the saponified acidic phosphorus-containing extractant and kerosene mixture, the ratio of saponifying agent to the acidic phosphorus-containing extractant and kerosene mixture is 20~40:60~80;

[0032] The ratio of the acidic phosphorus-containing extractant to the kerosene mixture is 5%~40%: 95%~60%.

[0033] Preferably, in step S5 or S7, the saponifying agent is selected from sodium hydroxide or ammonia.

[0034] Preferably, in step S6, the acid solution used in the first washing process is 90 g / L hydrochloric acid;

[0035] In the first back-extraction process, the acid solution used is 200 g / L nitric acid.

[0036] During the first washing or first back-extraction process, the volume ratio of acid solution to organic phase is 6~10:1, the mixing time of extraction is 3~10 min, and the standing time is 20~60 min.

[0037] Preferably, in step S8, the acid solution used in the second washing process is 90 g / L sulfuric acid;

[0038] In the second back-extraction process, the acid solution used is 150 g / L sulfuric acid.

[0039] Preferably, during the second washing or second back-extraction process, the volume ratio of acid solution to organic phase is 6~10:1, the mixing time of extraction is 3~10 min, and the standing time is 20~60 min.

[0040] Preferably, in step S9, during the second precipitation reaction, the molar ratio of cobalt ions in the cobalt-rich aqueous phase to bicarbonate ions in the ammonium bicarbonate solution is not less than 2.

[0041] Preferably, in step S9, the ammonium bicarbonate solution used in the second precipitation reaction is...

[0042] The concentration is 100~200g / L.

[0043] Preferably, in step S9, during the second precipitation reaction, the pH is 8-9, the temperature is 40-80℃, and the time is 1-3h.

[0044] Preferably, in step S6, the temperature for calcining the manganese-rich aqueous phase is 200~600℃, and the time is 1~3h.

[0045] Preferably, in step S9, the temperature for calcining the cobalt-rich aqueous phase is 600~800℃, and the time is 3~5h.

[0046] Compared with the prior art, the beneficial effects of this application include at least the following:

[0047] 1. This application uses a mixed solution of sulfuric acid and hydrogen peroxide to leach lanthanum, strontium, manganese and cobalt waste, and then uses a water / hydrochloric acid solution to leach the leaching residue a second time. After extracting, washing and back-extracting the leachate with an acidic phosphorus-containing organic extractant and acid solvents of different concentrations, lanthanum, strontium, manganese and cobalt elements are successfully separated from the lanthanum, strontium, manganese and cobalt waste, realizing the resource utilization of lanthanum, strontium, manganese and cobalt.

[0048] 2. This application uses sodium sulfate to react with lanthanum in the leachate to form a sodium sulfate lanthanum double salt precipitate, which improves the recovery rate of lanthanum.

[0049] 3. This application optimizes the concentrations of sulfuric acid and hydrogen peroxide, the concentration of hydrochloric acid, the pH during lanthanum hydroxide precipitation, the ratio of sodium sulfate to leachate during sodium sulfate lanthanum double salt precipitation, the extraction time during extraction, the type of acid solution during washing and back-extraction, and the amount of ammonium bicarbonate used during cobalt carbonate precipitation, thereby improving the recovery rates of elements such as lanthanum, strontium, manganese, and cobalt. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a schematic flowchart illustrating a method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste, as provided in Embodiment 1 of this application. Detailed Implementation

[0052] This application provides a method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste, thereby addressing the technical problem of the lack of existing methods for recovering lanthanum, strontium, manganese, and cobalt.

[0053] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0054] Given the current research focus primarily on the recovery of cobalt and manganese, and the lack of research on the recovery of lanthanum and strontium, this application provides a method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum-strontium-manganese-cobalt waste. The method includes: firstly, leaching the lanthanum-strontium-manganese-cobalt waste in a mixed solution of sulfuric acid and hydrogen peroxide to obtain a leachate and a leachate residue; secondly, leaching the leachate residue in a solution of water and hydrochloric acid to obtain a lanthanum-containing leachate and a strontium sulfate leachate residue; subsequently, adding an alkaline reagent to the lanthanum-containing leachate for a first precipitation reaction and filtering to obtain lanthanum hydroxide precipitate; and finally, adding sodium sulfate to the leachate for a double salt reaction and filtering. A sodium sulfate lanthanum double salt precipitate and a manganese-cobalt mixed filtrate were obtained. Next, a first acidic phosphorus-containing organic extractant was added to the manganese-cobalt mixed filtrate for a first extraction, yielding a manganese-rich organic phase and a cobalt-rich aqueous phase. An acid solution was added to the manganese-rich organic phase for a first back-extraction, followed by calcination of the manganese-rich aqueous phase to obtain manganese oxide. A second acidic phosphorus-containing organic extractant was added to the cobalt-rich aqueous phase for a second extraction, yielding a cobalt-rich organic phase. An acid solution was then added to the cobalt-rich organic phase for a second back-extraction, yielding a cobalt-rich aqueous phase. Finally, a second precipitation reaction was carried out with sodium bicarbonate solution in the cobalt-rich aqueous phase, followed by filtration. The precipitate was then calcined and filtered to obtain cobalt oxide.

[0055] The method for recovering lanthanum, strontium, manganese, and cobalt from lanthanum-strontium-manganese-cobalt waste provided in this application uses sulfuric acid to leach the waste. The combination of sulfuric acid and hydrogen peroxide has a good leaching effect on manganese and cobalt, but it is difficult to leach lanthanum and strontium. As a result, the leachate mainly contains manganese and cobalt, while the leaching residue mainly contains lanthanum and strontium. The leaching residue is then leached with hydrochloric acid solution to separate the lanthanum-containing leachate and the strontium sulfate leaching residue, thus separating the strontium element solid from the lanthanum-strontium-manganese-cobalt waste. Subsequently, an alkaline solution is added to the lanthanum-containing leachate to generate lanthanum hydroxide precipitate, thus separating the lanthanum element solid from the lanthanum-strontium-manganese-cobalt waste. Subsequently, the leachate containing manganese and cobalt was extracted using an acidic phosphorus-containing organic extractant, and then back-extracted with an acidic solution to obtain manganese-rich and cobalt-rich solutions. The manganese-rich solution was calcined in air to obtain manganese oxide, while the cobalt-rich solution was converted with sodium bicarbonate and then calcined in air to obtain cobalt oxide. Strontium and cobalt solids were separated from the lanthanum-strontium-manganese-cobalt waste. Thus, the method provided in this application successfully recovered lanthanum, strontium, manganese, and cobalt from the lanthanum-strontium-manganese-cobalt waste, realizing the resource utilization of lanthanum, strontium, manganese, and cobalt, and overcoming the deficiency of lack of research on the recovery of lanthanum and strontium.

[0056] As a preferred technical solution, in order to improve the recovery effect of lanthanum, this application treats a small portion of the lanthanum in the leachate by using sodium sulfate in the leachate. The sodium sulfate reacts with the lanthanum in the leachate to form a sodium sulfate lanthanum double salt precipitate.

[0057] As a preferred technical solution, in order to enrich the types of lanthanum and strontium recovery products, this application also uses sodium carbonate to convert strontium sulfate leaching residue into strontium carbonate, and calcines lanthanum hydroxide into lanthanum oxide.

[0058] As a preferred technical solution, in order to improve the leaching effect in a single leaching process, the sulfuric acid used in this application has a concentration range of 50 g / L to 300 g / L, and the hydrogen peroxide has a concentration range of 40 to 60%.

[0059] As a preferred technical solution, in order to improve the leaching effect in the secondary leaching process, the concentration of the hydrochloric acid solution used in this application is 2~6 mol / L, and the liquid-solid ratio of the hydrochloric acid solution to the leaching residue is 2~8:1.

[0060] As a preferred technical solution, in order to promote the formation of lanthanum hydroxide precipitate, this application uses alkaline reagents such as sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium bicarbonate or ammonia to adjust the pH of the reaction to 10-14.

[0061] As a preferred technical solution, in order to promote the formation of sodium sulfate lanthanum double salt precipitate during the double salt reaction and reduce lanthanum residue in the leachate, the volume-to-mass ratio of leachate to sodium sulfate used in this application is 100:10~20, that is, 10~20g of sodium sulfate is added to every 100ml of leachate.

[0062] As a preferred technical solution, in order to promote the extraction effect and obtain manganese-rich organic phase and cobalt-rich organic phase, the mixing time of the extraction in the first extraction and the second extraction process is 3~10 min and the standing time is 20~60 min.

[0063] As a preferred technical solution, in order to promote the back-extraction effect and obtain high-purity manganese-rich and cobalt-rich aqueous phases, this application uses acid solutions such as sulfuric acid, hydrochloric acid, and nitric acid for washing and back-extraction.

[0064] As a preferred technical solution, in order to improve the cobalt recovery effect, during the second precipitation reaction, since cobalt ions and bicarbonate ions will first form unstable cobalt bicarbonate, the ammonium bicarbonate solution used in this application needs to be in excess, that is, the molar ratio of cobalt ions in the cobalt-rich aqueous phase to bicarbonate ions in the ammonium bicarbonate solution is not less than 2, more preferably more than 2.2 times.

[0065] The following will provide a detailed description of a method for recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste, based on examples and recovery data of lanthanum, strontium, manganese, and cobalt.

[0066] Example 1

[0067] Example 1 of this application provides a method for recovering lanthanum, strontium, manganese, and cobalt separately from lanthanum, strontium, manganese, and cobalt waste, including the steps of leaching the lanthanum, strontium, manganese, and cobalt waste, the step of secondary leaching of the leaching residue, the step of recovering strontium carbonate, the step of recovering lanthanum hydroxide precipitate, the step of recovering lanthanum oxide, the step of recovering sodium sulfate lanthanum double salt precipitate, the step of recovering manganese oxide, and the step of recovering cobalt oxide.

[0068] The leaching steps for lanthanum-strontium-manganese-cobalt waste include: pouring 400g of water and 100g of lanthanum-strontium-manganese-cobalt waste into a container, turning on the magnetic stirrer at 300rpm. After stirring evenly, slowly adding 100ml of 245g / L sulfuric acid until the pH=0, raising the temperature to 60~100℃, slowly adding 45g of 50% hydrogen peroxide, reacting for 4 hours for leaching, filtering to obtain the leachate and leaching residue. 400g of lanthanum-strontium-manganese-cobalt waste includes 36g of cobalt (9%), 114g of manganese (28.5%), 135.2g of lanthanum (33.8%), and 21.6g of strontium (5.4%).

[0069] The steps for secondary leaching of the leaching residue include: washing the leaching residue with water slurry at a liquid-to-solid ratio of 2 / 1, and washing it three times with cross-flow to obtain a water-washed residue; adding 600 mL of hydrochloric acid (concentration 4 mol / L) and 100 g of water-washed residue to a beaker at a liquid-to-solid ratio of 6 / 1, turning on magnetic stirring at a speed of 300 rpm; heating to 80℃ and reacting for 2 hours for secondary leaching; and filtering to obtain a lanthanum-containing leaching solution and strontium sulfate-containing leaching residue.

[0070] The steps for recovering strontium carbonate include: taking 50g of strontium sulfate leaching residue obtained from the second leaching, adding 300mL of sodium carbonate solution (concentration 0.5mol / L) at a liquid-to-solid ratio of 6:1, leaching at a liquid-to-solid ratio of 6:1, heating to 60~70℃, controlling pH=11~12, reacting for 6h, aging for 1h, filtering, washing the filter residue with water until the washing liquid pH=7~8, and drying to obtain solid strontium carbonate.

[0071] The steps for recovering lanthanum hydroxide precipitate include: taking 200 mL of lanthanum-containing leachate obtained from the second leaching, heating it to 60-70℃, adding sodium hydroxide to pH=12, stirring the reaction for 1 h, aging for 0.5 h, filtering to obtain lanthanum hydroxide filter residue; and washing the lanthanum hydroxide filter residue with water to pH=7-8.

[0072] The steps for recovering lanthanum oxide include: drying lanthanum hydroxide and then calcining it at 750°C for 2 hours to obtain solid lanthanum oxide.

[0073] The steps for recovering sodium lanthanum sulfate double salt precipitate include: taking 200 mL of leachate, heating to 80 °C, adding sodium carbonate until the pH of the leachate is 4.0, then adding 30 g of sodium sulfate and reacting for 1 h, and filtering to obtain a manganese-cobalt mixed filtrate and sodium lanthanum sulfate double salt precipitate.

[0074] The steps for recovering manganese oxide include:

[0075] Mix 25% P204 extractant with 75% kerosene (i.e., 200 mL of P204 extractant and 600 mL of kerosene) to prepare the P204 organic phase. Then add 33 mL of 32% liquid alkali for saponification, with a saponification rate of 50% to 60%. Mix thoroughly to obtain the P204 saponified organic phase, which is the first acidic phosphorus-containing organic extractant.

[0076] Take the first acidic phosphorus-containing organic extractant and the manganese-cobalt mixed filtrate at O / A=4 / 1, that is, 800 mL of P204 saponified organic phase / 200 mL of manganese-cobalt mixed filtrate, mix for 5 min, let stand for 40 min to separate phases. The upper layer is the P204-rich manganese organic phase, and the lower aqueous phase is the P204 raffinate, that is, the cobalt-rich aqueous phase.

[0077] Take P204 manganese-rich organic phase and hydrochloric acid (concentration 90 g / L), mix them at O / A = 8 / 1 (i.e., 800 mL P204 manganese-rich organic phase / 100 mL hydrochloric acid) for 5 min, and let them stand for 40 min to separate the phases. The upper layer is the organic phase after washing with P204. The lower layer is the aqueous phase.

[0078] Take the organic phase after washing P204 and nitric acid (concentration 200g / L), and mix them at O / A=8 / 1=800mL, that is, the washed P204 manganese-rich organic phase / 100mL nitric acid for 5min. Let it stand for 40min to separate the phases. The upper layer is the organic phase after P204 back-extraction, and the lower layer is the P204 back-extraction solution, that is, manganese nitrate solution.

[0079] Take the P204 back-extraction solution (manganese nitrate solution), heat it to 400℃, and calcine it for 2 hours to obtain manganese dioxide.

[0080] The steps for recovering cobalt oxide include:

[0081] Mix 30% P507 extractant with 70% kerosene, i.e., 240 mL of P507 extractant and 560 mL of kerosene, and prepare the P507 organic phase. Then add 33 mL of 32% liquid alkali for saponification, with a saponification rate of 50%~60%. Mix well to obtain the P507 saponified organic phase, which is the second acidic phosphorus-containing organic extractant.

[0082] Take the second acidic phosphorus-containing organic extractant and P204 raffinate, mix them at O / A=4 / 1 (800 mL of saponified organic phase of P507 / 200 mL of P204 raffinate) for 5 min, and let them stand for 45 min to separate the phases. The upper layer is the cobalt-rich organic phase of P507, and the lower aqueous phase is mainly composed of sodium sulfate solution.

[0083] Take P507 cobalt-rich organic phase and sulfuric acid (concentration 90g / L), mix them according to O / A=8 / 1, that is, 800mL P507 cobalt-rich organic phase / 100mL sulfuric acid, mix for 5min, let stand for 40min to separate the phases, the upper layer is the organic phase after washing P507, and the lower layer is the aqueous phase.

[0084] Take the organic phase after washing P507 and sulfuric acid (concentration 150g / L), mix them at O / A=8 / 1, that is, 800mL of washed P507 cobalt-rich organic phase / 100mL of sulfuric acid, mix for 5min, let stand for 40min to separate the phases, the upper layer is the organic phase after P507 back-extraction, and the lower layer is the P507 back-extraction solution, that is, cobalt sulfate solution.

[0085] Take an excess of 150 g / L ammonium bicarbonate base solution, the amount of base solution is calculated according to the molar ratio of ammonium bicarbonate to cobalt = 2.2 / 1, and slowly add P507 back-extraction solution (cobalt sulfate solution) for 0.5~2 h. Adjust the pH to 8~9, set the temperature to 60℃, age for 2 h, filter, wash the filter cake with water to remove sulfate ions, dry it, and calcine at 700℃ for 4 h to obtain cobalt oxide.

[0086] Example 2

[0087] Example 2 of this application provides a method for recovering lanthanum, strontium, manganese, and cobalt separately from lanthanum, strontium, manganese, and cobalt waste, including the steps of leaching the lanthanum, strontium, manganese, and cobalt waste, the step of secondary leaching of the leaching residue, the step of recovering strontium carbonate, the step of recovering lanthanum hydroxide precipitate, the step of recovering lanthanum oxide, the step of recovering sodium sulfate lanthanum double salt precipitate, the step of recovering manganese oxide, and the step of recovering cobalt oxide.

[0088] The leaching steps for lanthanum-strontium-manganese-cobalt waste include: pouring 600g of water and 100g of lanthanum-strontium-manganese-cobalt waste into a container, turning on the magnetic stirrer at 300rpm. After stirring evenly, slowly adding 100ml of 245g / L sulfuric acid until the pH=0, raising the temperature to 60~100℃, slowly adding 45g of 50% hydrogen peroxide, reacting for 4 hours for leaching, filtering to obtain the leachate and leaching residue. 400g of lanthanum-strontium-manganese-cobalt waste includes 36g of cobalt (9%), 114g of manganese (28.5%), 135.2g of lanthanum (33.8%), and 21.6g of strontium (5.4%).

[0089] The steps for secondary leaching of the leaching residue include: washing the leaching residue with water slurry at a liquid-to-solid ratio of 2 / 1, and washing it three times with cross-flow to obtain a water-washed residue; adding 600 mL of hydrochloric acid (concentration 4 mol / L) and 100 g of water-washed residue to a beaker at a liquid-to-solid ratio of 6 / 1, turning on magnetic stirring at a speed of 300 rpm; heating to 80℃ and reacting for 2 hours for secondary leaching; and filtering to obtain a lanthanum-containing leaching solution and strontium sulfate-containing leaching residue.

[0090] The steps for recovering strontium carbonate include: taking 50g of strontium sulfate leaching residue obtained from the second leaching, adding 300mL of sodium carbonate solution (concentration 0.5mol / L) at a liquid-to-solid ratio of 6:1, leaching at a liquid-to-solid ratio of 6:1, heating to 60~70℃, controlling pH=11~12, reacting for 6h, aging for 1h, filtering, washing the filter residue with water until the washing liquid pH=7~8, and drying to obtain solid strontium carbonate.

[0091] The steps for recovering lanthanum hydroxide precipitate include: taking 200 mL of lanthanum-containing leachate obtained from the second leaching, heating it to 60-70℃, adding sodium hydroxide to pH=12, stirring the reaction for 1 h, aging for 0.5 h, filtering to obtain lanthanum hydroxide filter residue; and washing the lanthanum hydroxide filter residue with water to pH=7-8.

[0092] The steps for recovering lanthanum oxide include: drying lanthanum hydroxide and then calcining it at 750°C for 2 hours to obtain solid lanthanum oxide.

[0093] The steps for recovering sodium lanthanum sulfate double salt precipitate include: taking 200 mL of leachate, heating to 80 °C, adding sodium carbonate until the pH of the leachate is 4.0, then adding 30 g of sodium sulfate and reacting for 1 h, and filtering to obtain a manganese-cobalt mixed filtrate and sodium lanthanum sulfate double salt precipitate.

[0094] The steps for recovering manganese oxide include:

[0095] Mix 25% P204 extractant with 75% kerosene (i.e., 200 mL of P204 extractant and 600 mL of kerosene) to prepare the P204 organic phase. Then add 33 mL of 32% liquid alkali for saponification, with a saponification rate of 50% to 60%. Mix thoroughly to obtain the P204 saponified organic phase, which is the first acidic phosphorus-containing organic extractant.

[0096] Take the first acidic phosphorus-containing organic extractant and the manganese-cobalt mixed filtrate at O / A=4 / 1, that is, 800 mL of P204 saponified organic phase / 200 mL of manganese-cobalt mixed filtrate, mix for 5 min, let stand for 40 min to separate phases. The upper layer is the P204-rich manganese organic phase, and the lower aqueous phase is the P204 raffinate, that is, the cobalt-rich aqueous phase.

[0097] Take P204 manganese-rich organic phase and hydrochloric acid (concentration 90 g / L), mix them at O / A = 8 / 1 (i.e., 800 mL P204 manganese-rich organic phase / 100 mL hydrochloric acid) for 5 min, and let them stand for 40 min to separate the phases. The upper layer is the organic phase after washing with P204. The lower layer is the aqueous phase.

[0098] Take the organic phase after washing P204 and nitric acid (concentration 200g / L), and mix them at O / A=8 / 1=800mL, that is, the washed P204 manganese-rich organic phase / 100mL nitric acid for 5min. Let it stand for 40min to separate the phases. The upper layer is the organic phase after P204 back-extraction, and the lower layer is the P204 back-extraction solution, that is, manganese nitrate solution.

[0099] Take the P204 back-extraction solution (manganese nitrate solution), heat it to 400℃, and calcine it for 2 hours to obtain manganese dioxide.

[0100] The steps for recovering cobalt oxide include:

[0101] Mix 30% P507 extractant with 70% kerosene, i.e., 240 mL of P507 extractant and 560 mL of kerosene, and prepare the P507 organic phase. Then add 33 mL of 32% liquid alkali for saponification, with a saponification rate of 50%~60%. Mix well to obtain the P507 saponified organic phase, which is the second acidic phosphorus-containing organic extractant.

[0102] Take the second acidic phosphorus-containing organic extractant and P204 raffinate, mix them at O / A=4 / 1 (800 mL of saponified organic phase of P507 / 200 mL of P204 raffinate) for 5 min, and let them stand for 45 min to separate the phases. The upper layer is the cobalt-rich organic phase of P507, and the lower aqueous phase is mainly composed of sodium sulfate solution.

[0103] Take P507 cobalt-rich organic phase and sulfuric acid (concentration 90g / L), mix them according to O / A=8 / 1, that is, 800mL P507 cobalt-rich organic phase / 100mL sulfuric acid, mix for 5min, let stand for 40min to separate the phases, the upper layer is the organic phase after washing P507, and the lower layer is the aqueous phase.

[0104] Take the organic phase after washing P507 and sulfuric acid (concentration 150g / L), mix them at O / A=8 / 1, that is, 800mL of washed P507 cobalt-rich organic phase / 100mL of sulfuric acid, mix for 5min, let stand for 40min to separate the phases, the upper layer is the organic phase after P507 back-extraction, and the lower layer is the P507 back-extraction solution, that is, cobalt sulfate solution.

[0105] Take an excess of 100 g / L ammonium bicarbonate base solution, the amount of base solution is calculated according to the molar ratio of ammonium bicarbonate / cobalt = 2.2 / 1, and slowly add P507 back-extraction solution (cobalt sulfate solution) for 0.5~2 h. Adjust the pH to 8~9, set the temperature to 60℃, age for 2 h, filter, wash the filter cake with water to remove sulfate ions, dry it, and calcine at 700℃ for 4 h to obtain cobalt oxide.

[0106] Example 3

[0107] Example 3 of this application provides a method for recovering lanthanum, strontium, manganese, and cobalt separately from lanthanum, strontium, manganese, and cobalt waste, including the steps of leaching the lanthanum, strontium, manganese, and cobalt waste, the step of secondary leaching of the leaching residue, the step of recovering strontium carbonate, the step of recovering lanthanum hydroxide precipitate, the step of recovering lanthanum oxide, the step of recovering sodium sulfate lanthanum double salt precipitate, the step of recovering manganese oxide, and the step of recovering cobalt oxide.

[0108] The leaching steps for lanthanum-strontium-manganese-cobalt waste include: pouring 500g of water and 100g of lanthanum-strontium-manganese-cobalt waste into a container, turning on the magnetic stirrer at 300rpm. After stirring evenly, slowly adding 100ml of 245g / L sulfuric acid until the pH=0, raising the temperature to 60~100℃, slowly adding 45g of 50% hydrogen peroxide, reacting for 4 hours for leaching, filtering to obtain the leachate and leaching residue. 400g of lanthanum-strontium-manganese-cobalt waste includes 36g of cobalt (9%), 114g of manganese (28.5%), 135.2g of lanthanum (33.8%), and 21.6g of strontium (5.4%).

[0109] The steps for secondary leaching of the leaching residue include: washing the leaching residue with water slurry at a liquid-to-solid ratio of 2 / 1, and washing it three times with cross-flow to obtain a water-washed residue; adding 600 mL of hydrochloric acid (concentration 4 mol / L) and 100 g of water-washed residue to a beaker at a liquid-to-solid ratio of 6 / 1, turning on magnetic stirring at a speed of 300 rpm; heating to 80℃ and reacting for 2 hours for secondary leaching; and filtering to obtain a lanthanum-containing leaching solution and strontium sulfate-containing leaching residue.

[0110] The steps for recovering strontium carbonate include: taking 50g of strontium sulfate leaching residue obtained from the second leaching, adding 300mL of sodium carbonate solution (concentration 0.5mol / L) at a liquid-to-solid ratio of 6:1, leaching at a liquid-to-solid ratio of 6:1, heating to 60~70℃, controlling pH=11~12, reacting for 6h, aging for 1h, filtering, washing the filter residue with water until the washing liquid pH=7~8, and drying to obtain solid strontium carbonate.

[0111] The steps for recovering lanthanum hydroxide precipitate include: taking 200 mL of lanthanum-containing leachate obtained from the second leaching, heating it to 60-70℃, adding sodium hydroxide to pH=12, stirring the reaction for 1 h, aging for 0.5 h, filtering to obtain lanthanum hydroxide filter residue; and washing the lanthanum hydroxide filter residue with water to pH=7-8.

[0112] The steps for recovering lanthanum oxide include: drying lanthanum hydroxide and then calcining it at 750°C for 2 hours to obtain solid lanthanum oxide.

[0113] The steps for recovering sodium lanthanum sulfate double salt precipitate include: taking 200 mL of leachate, heating to 80 °C, adding sodium carbonate until the pH of the leachate is 4.0, then adding 30 g of sodium sulfate and reacting for 1 h, and filtering to obtain a manganese-cobalt mixed filtrate and sodium lanthanum sulfate double salt precipitate.

[0114] The steps for recovering manganese oxide include:

[0115] Mix 25% P204 extractant with 75% kerosene (i.e., 200 mL of P204 extractant and 600 mL of kerosene) to prepare the P204 organic phase. Then add 33 mL of 32% liquid alkali for saponification, with a saponification rate of 50% to 60%. Mix thoroughly to obtain the P204 saponified organic phase, which is the first acidic phosphorus-containing organic extractant.

[0116] Take the first acidic phosphorus-containing organic extractant and the manganese-cobalt mixed filtrate at O / A=4 / 1, that is, 800 mL of P204 saponified organic phase / 200 mL of manganese-cobalt mixed filtrate, mix for 5 min, let stand for 40 min to separate phases. The upper layer is the P204-rich manganese organic phase, and the lower aqueous phase is the P204 raffinate, that is, the cobalt-rich aqueous phase.

[0117] Take P204 manganese-rich organic phase and hydrochloric acid (concentration 90 g / L), mix them at O / A = 8 / 1 (i.e., 800 mL P204 manganese-rich organic phase / 100 mL hydrochloric acid) for 5 min, and let them stand for 40 min to separate the phases. The upper layer is the organic phase after washing with P204. The lower layer is the aqueous phase.

[0118] Take the organic phase after washing P204 and nitric acid (concentration 200g / L), and mix them at O / A=8 / 1=800mL, that is, the washed P204 manganese-rich organic phase / 100mL nitric acid for 5min. Let it stand for 40min to separate the phases. The upper layer is the organic phase after P204 back-extraction, and the lower layer is the P204 back-extraction solution, that is, manganese nitrate solution.

[0119] Take the P204 back-extraction solution (manganese nitrate solution), heat it to 400℃, and calcine it for 2 hours to obtain manganese dioxide.

[0120] The steps for recovering cobalt oxide include:

[0121] Mix 30% P507 extractant with 70% kerosene, i.e., 240 mL of P507 extractant and 560 mL of kerosene, and prepare the P507 organic phase. Then add 33 mL of 32% liquid alkali for saponification, with a saponification rate of 50%~60%. Mix well to obtain the P507 saponified organic phase, which is the second acidic phosphorus-containing organic extractant.

[0122] Take the second acidic phosphorus-containing organic extractant and P204 raffinate, mix them at O / A=4 / 1 (800 mL of saponified organic phase of P507 / 200 mL of P204 raffinate) for 5 min, and let them stand for 45 min to separate the phases. The upper layer is the cobalt-rich organic phase of P507, and the lower aqueous phase is mainly composed of sodium sulfate solution.

[0123] Take P507 cobalt-rich organic phase and sulfuric acid (concentration 90g / L), mix them according to O / A=8 / 1, that is, 800mL P507 cobalt-rich organic phase / 100mL sulfuric acid, mix for 5min, let stand for 40min to separate the phases, the upper layer is the organic phase after washing P507, and the lower layer is the aqueous phase.

[0124] Take the organic phase after washing P507 and sulfuric acid (concentration 150g / L), mix them at O / A=8 / 1, that is, 800mL of washed P507 cobalt-rich organic phase / 100mL of sulfuric acid, mix for 5min, let stand for 40min to separate the phases, the upper layer is the organic phase after P507 back-extraction, and the lower layer is the P507 back-extraction solution, that is, cobalt sulfate solution.

[0125] Take an excess of 200 g / L ammonium bicarbonate base solution, calculated based on the molar ratio of ammonium bicarbonate to cobalt = 2.2 / 1. Simultaneously, slowly add P507 back-extraction solution (cobalt sulfate solution) over a period of 0.5–2 hours. Adjust the pH to 8–9, maintain the temperature at 60°C, and age for 2 hours. Filter the solution, wash the filter cake with water to remove sulfate ions, dry it, and calcine it at 700°C for 4 hours to obtain cobalt oxide.

[0126] Example 4

[0127] This Example 4 presents the recovery data for the method provided in Examples 1-3 for recovering lanthanum, strontium, manganese, and cobalt from lanthanum-strontium-manganese-cobalt waste, as shown in Table 1.

[0128]

[0129] As can be seen from Table 1, the recycling methods provided in Examples 1-3 of this application can recover valuable metals such as cobalt, manganese, lanthanum, and strontium from the same batch of lanthanum-strontium-manganese-cobalt waste (including 9% cobalt, 28.5% manganese, 33.8% lanthanum, 5.4% strontium, and 23.3% inexpensive metals), with a recovery rate of over 92.0% and a recovery purity of over 95.8%. This indicates that the recycling methods for lanthanum-strontium-manganese-cobalt waste provided in Examples 1-3 of this application successfully recovered valuable metals such as cobalt, manganese, lanthanum, and strontium, and the recovery effect is good.

[0130] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste, characterized in that, Including the following steps: Step S1: The lanthanum, strontium, manganese and cobalt waste is leached once in a mixed solution of sulfuric acid and hydrogen peroxide to obtain leachate and leaching residue; Step S2: The leaching residue is placed in hydrochloric acid solution for a second leaching to obtain lanthanum-containing leaching solution and strontium sulfate leaching residue; Step S3: Add an alkaline reagent to the lanthanum-containing leachate to carry out the first precipitation reaction, then filter to obtain lanthanum hydroxide precipitate; Step S4: Add sodium sulfate to the leachate to carry out a double salt reaction, then filter to obtain sodium sulfate lanthanum double salt precipitate and manganese-cobalt mixed filtrate; Step S5: Add the first acidic phosphorus-containing organic extractant to the manganese-cobalt mixed filtrate for the first extraction to obtain a manganese-rich organic phase and a cobalt-rich aqueous phase. Step S6: After adding an acid solution to the manganese-rich organic phase for the first washing and the first back-extraction, the manganese-rich aqueous phase is calcined to obtain manganese oxide. Step S7: Add a second acidic phosphorus-containing organic extractant to the cobalt-rich aqueous phase for a second extraction to obtain a cobalt-rich organic phase; Step S8: After adding acid solution to the cobalt-rich organic phase for a second washing and a second back-extraction, a cobalt-rich aqueous phase is obtained. Step S9: After the sodium bicarbonate solution in the cobalt-rich aqueous phase undergoes a second precipitation reaction, it is filtered, and the precipitate is obtained by calcination and filtration.

2. The method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, Following step S2, the process further includes the step of carbonating the strontium sulfate leaching residue in a sodium carbonate solution to obtain solid strontium carbonate.

3. The method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, Following step S3, the process also includes calcining the lanthanum hydroxide precipitate to obtain lanthanum oxide.

4. The method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S1, during the single leaching process, the concentration of sulfuric acid used is 50 g / L to 300 g / L, and the concentration of hydrogen peroxide is 40 to 60%.

5. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S2, during the secondary leaching process, the concentration of the hydrochloric acid solution used is 2~6 mol / L, and the liquid-solid ratio of the hydrochloric acid solution to the leaching residue is 2~8:

1.

6. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S3, during the first precipitation reaction, the alkaline reagent used is sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium bicarbonate, or ammonia, and the pH of the reaction is 10-14.

7. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S4, during the double salt reaction, the volume-to-mass ratio of the leachate to sodium sulfate used is 100 mL: 10~20 g.

8. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S5 or S7, the mixing time for extraction is 3-10 min, and the settling time is 20-60 min.

9. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S6 or S8, during the first washing, second washing, or first back-extraction, second back-extraction, the volume ratio of acid solution to organic phase is 6~10:1, the mixing time of extraction is 3~10 min, and the standing time is 20~60 min.

10. A method for separately recovering lanthanum, strontium, manganese, and cobalt from lanthanum, strontium, manganese, and cobalt waste according to claim 1, characterized in that, In step S9, during the second precipitation reaction, the molar ratio of cobalt ions in the cobalt-rich aqueous phase to bicarbonate ions in the ammonium bicarbonate solution is not less than 2.

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