Method for respectively recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt wastes

Abstract

The invention belongs to the technical field of recycling of renewable resources, and particularly relates to a method for recycling lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials. The invention provides a method for respectively recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt wastes, which comprises the following steps: leaching the lanthanum, strontium, manganese and cobalt wastes by using sulfuric acid and hydrogen peroxide to obtain leaching residues rich in lanthanum and strontium and a leaching solution containing manganese and cobalt, and then leaching the leaching residues for the second time by using hydrochloric acid to obtain a leaching solution containing lanthanum and strontium sulfate leaching residues, alkali liquor is added into the lanthanum-containing leachate to generate lanthanum hydroxide, then sodium salt such as sodium sulfate is added into the manganese-cobalt-containing leachate for double salt reaction to obtain sodium-lanthanum sulfate double salt and manganese-cobalt mixed filtrate, and then the manganese-cobalt mixed filtrate is subjected to the steps of extraction, washing, back extraction, calcination and the like to obtain manganese oxide and cobalt oxide. The valuable metals such as lanthanum, strontium, manganese and cobalt are recycled from the lanthanum-strontium-manganese-cobalt waste, and the technical problem that in the prior art, a method for recycling lanthanum, strontium, manganese and cobalt is lacked is solved.

Description

Technical Field

[0001] The present application belongs to the field of renewable resource recovery technology, and in particular relates to a method for respectively recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials. Background Art

[0002] At present, the Fe-Cr alloy connectors of solid-state fuel cells (SOFCs) use lanthanum strontium manganese cobalt composite oxide (LSM / MCO) as a protective coating material. The lanthanum strontium manganese cobalt composite oxide coating can improve the Cr poisoning and high-temperature conductivity of the Fe-Cr alloy in the high-temperature working environment of the solid-state fuel cell, which is beneficial to the stable operation of the solid-state fuel cell.

[0003] When a lanthanum, strontium, manganese and cobalt composite oxide protective coating is prepared on the surface of a Fe-Cr alloy connector by a spraying process, lanthanum, strontium, manganese and cobalt waste is generated. At the same time, some Fe-Cr alloy connectors cannot pass the quality inspection and are defective products. Defective Fe-Cr alloy connectors will also generate lanthanum, strontium, manganese and cobalt waste. If the waste is directly discarded, it may cause environmental pollution and waste of valuable metal resources. Therefore, it is necessary to recycle the valuable metal resources such as lanthanum, strontium, manganese and cobalt in the lanthanum, strontium, manganese and cobalt waste.

[0004] Nickel-cobalt-manganese materials, as ternary positive electrode materials for lithium batteries, are widely used in energy storage devices, power batteries, new energy vehicles and other fields. With the development of new energy technologies, there are many studies on the recovery of cobalt and manganese in waste, but there is a lack of research on the recovery of lanthanum and strontium. There are differences in the properties of cobalt, manganese, lanthanum and strontium. The recovery technology of cobalt and manganese cannot be directly used for the recovery of lanthanum and strontium. Therefore, it is necessary to develop a suitable method to recycle the cobalt, manganese, lanthanum and strontium in waste. Summary of the invention

[0005] In view of this, the present application provides a method for recovering lanthanum, strontium, manganese and cobalt respectively from lanthanum, strontium, manganese and cobalt waste materials, which is used 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 the present application provides a method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials, the method comprising the steps of:

[0007] Step S1, placing the lanthanum, strontium, manganese and cobalt waste in a mixed solution of sulfuric acid and hydrogen peroxide for one time leaching to obtain a leachate and a leaching residue;

[0008] Step S2, placing the leached residue in a hydrochloric acid solution for secondary leaching to obtain a lanthanum-containing leaching solution and strontium sulfate leaching residue;

[0009] Step S3, adding an alkaline reagent to the lanthanum-containing leachate to perform a first precipitation reaction and then filtering to obtain a lanthanum hydroxide precipitate;

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

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

[0012] Step S6, adding an acid solution to the manganese-rich organic phase for a first washing and a first stripping, and then calcining the manganese-rich aqueous phase to obtain manganese oxide;

[0013] Step S7, adding 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, adding an acid solution to the cobalt-rich organic phase for a second washing and a second stripping to obtain a cobalt-rich aqueous phase;

[0015] Step S9, subjecting the sodium bicarbonate solution in the cobalt-rich aqueous phase to a second precipitation reaction, filtering the solution, and calcining and filtering the precipitate to obtain cobalt oxide.

[0016] Preferably, after step S2, the method further comprises 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 comprises the step of calcining the lanthanum hydroxide precipitate to obtain lanthanum oxide.

[0018] Preferably, in step S1, during the primary 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%.

[0019] Preferably, in step S1, during the primary leaching process, the stirring speed is 200-400 rpm, the temperature is 60-100° C., and the time is 2-6 hours.

[0020] Preferably, in step S2, during the secondary leaching process, the concentration of the hydrochloric acid solution used is 2-6 mol / L, and the liquid-to-solid ratio of the hydrochloric acid solution to the leached 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° C., and the time is 1-3 h.

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

[0023] Preferably, in step S3, the process of the first precipitation reaction is: stirring for 0.5 to 2 hours and aging for 0.2 to 1 hour at a temperature of 60 to 70° C. and a pH of 10 to 14.

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

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

[0026] Preferably, in step S5, during the first extraction, the first acidic phosphorus-containing organic extractant used is a mixture of a 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 and the manganese-cobalt mixed filtrate is 3-5:1, the extraction mixing time is 3-10 min, and the standing time is 20-60 min.

[0028] Preferably, in step S7, during the second extraction, the second acidic phosphorus-containing organic extractant used is a mixture of a 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 the saponifier to the acidic phosphorus-containing extractant and kerosene mixture is 20-40:60-80;

[0032] In the mixture of the acidic phosphorus-containing extractant and kerosene, 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 water.

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

[0035] During the first stripping process, the acid solution used was 200 g / L nitric acid.

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

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

[0038] During the second stripping process, the acid solution used was 150 g / L sulfuric acid.

[0039] Preferably, during the second washing or second stripping process, the volume ratio of the acid solution to the organic phase is 6-10:1, the mixing time of the 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, during the second precipitation reaction, the ammonium bicarbonate solution used 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° C., and the time is 1-3 hours.

[0044] Preferably, in step S6, the temperature of calcining the manganese-rich aqueous phase is 200-600° C. and the time is 1-3 hours.

[0045] Preferably, in step S9, the temperature of calcining the cobalt-rich aqueous phase is 600-800° C. and the time is 3-5 hours.

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

[0047] 1. The present 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 perform secondary leaching on the leached residue, and uses an acidic phosphorus-containing organic extractant and acid solvents of different concentrations to extract, wash and strip the leachate, thereby successfully separating lanthanum, strontium, manganese, cobalt and other elements from the lanthanum, strontium, manganese and cobalt waste, thereby realizing the resource utilization of lanthanum, strontium, manganese and cobalt.

[0048] 2. The present application uses sodium sulfate and lanthanum in the leaching solution to generate a double salt reaction to generate sodium sulfate lanthanum double salt precipitate, thereby improving the recovery rate of lanthanum.

[0049] 3. The present application optimizes the concentrations of sulfuric acid and hydrogen peroxide, the concentration of hydrochloric acid, the pH of lanthanum hydroxide precipitation, the ratio of sodium sulfate to leachate during precipitation of sodium lanthanum sulfate double salt, the extraction time during extraction, the type of acid solution during washing and stripping, and the amount of ammonium bicarbonate during cobalt carbonate precipitation, thereby improving the recovery rate of elements such as lanthanum, strontium, manganese, and cobalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A schematic flow chart of a method for separately recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials provided in Example 1 of the present application. DETAILED DESCRIPTION

[0052] The present application provides a method for respectively recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials, which is used to solve the technical problem of the lack of recovery methods for lanthanum, strontium, manganese and cobalt in the prior art.

[0053] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0054] In view of the defect that current research mainly focuses on the recovery of cobalt and manganese, and lacks research on the recovery of lanthanum and strontium, the present application provides a method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials, and the recovery method comprises: firstly placing the lanthanum, strontium, manganese and cobalt waste materials in a mixed solution of sulfuric acid and hydrogen peroxide for a primary leaching to obtain a leaching solution and a leaching residue; then placing the leaching residue in a water and hydrochloric acid solution for a secondary leaching to obtain a lanthanum-containing leaching solution and strontium sulfate leaching residue; then adding an alkaline reagent to the lanthanum-containing leaching solution for a first precipitation reaction and filtering to obtain a lanthanum hydroxide precipitate; then adding sodium sulfate to the leaching solution for a double salt reaction and filtering, Sodium lanthanum sulfate double salt precipitate and manganese-cobalt mixed filtrate are obtained; then a first acidic phosphorus-containing organic extractant is added to the manganese-cobalt mixed filtrate for a first extraction to obtain a manganese-rich organic phase and a cobalt-rich aqueous phase; an acid solution is added to the manganese-rich organic phase for a first back extraction, and the manganese-rich aqueous phase is calcined to obtain manganese oxide; a second acidic phosphorus-containing organic extractant is added to the cobalt-rich aqueous phase for a second extraction to obtain a cobalt-rich organic phase; an acid solution is added to the cobalt-rich organic phase for a second back extraction to obtain a cobalt-rich aqueous phase; then a sodium bicarbonate solution in the cobalt-rich aqueous phase is subjected to a second precipitation reaction and then filtered, and the filtered precipitate is calcined to obtain cobalt oxide.

[0055] In the method for recovering lanthanum, strontium, manganese and cobalt from lanthanum strontium manganese and cobalt waste provided in the present application, sulfuric acid is used to leach the lanthanum strontium manganese and cobalt waste, and sulfuric acid and hydrogen peroxide have a good leaching effect on manganese and cobalt after being compounded, and lanthanum strontium is difficult to be leached, so that the obtained leaching solution mainly contains manganese and cobalt, and the leaching residue mainly contains lanthanum and strontium; then the leaching residue is placed in a hydrochloric acid solution for leaching, the lanthanum-containing leaching solution and the strontium sulfate leaching residue are separated, and the strontium element solid is separated from the lanthanum strontium manganese and cobalt waste, and then an alkali solution is added to the lanthanum-containing leaching solution to generate a lanthanum hydroxide precipitate, and the lanthanum element solid is separated from the lanthanum strontium manganese and cobalt waste; Subsequently, the leachate containing manganese and cobalt is extracted with an acidic phosphorus-containing organic extractant and back-extracted with an acid solution to obtain a manganese-rich solution and a cobalt-rich solution. The manganese-rich solution can obtain manganese oxide after calcining in air, and the cobalt-rich solution can obtain cobalt oxide after being converted with sodium bicarbonate and calcined in air. Strontium and cobalt element solids are separated from lanthanum strontium manganese cobalt waste. Therefore, the method provided in the present application successfully recovers lanthanum, strontium, manganese and cobalt from lanthanum strontium manganese cobalt waste, realizes the resource utilization of lanthanum, strontium, manganese and cobalt, and overcomes the defect 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, the present application processes a small portion of lanthanum in the leachate, uses sodium sulfate in the leachate, and sodium sulfate and lanthanum in the leachate react to form a sodium sulfate lanthanum complex salt precipitate.

[0057] As a preferred technical solution, in order to enrich the types of recovered products of lanthanum and strontium, the present 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 during the primary leaching process, the concentration range of sulfuric acid used in this application is 50g / L~300g / L, and the concentration range of hydrogen peroxide is 40~60%.

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

[0060] As a preferred technical solution, in order to promote the formation of lanthanum hydroxide precipitation, the present application uses an alkaline reagent such as sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium bicarbonate or ammonia water 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 precipitation during the double salt reaction and reduce the lanthanum residue in the leachate, the volume mass ratio of the leachate and 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 a manganese-rich organic phase and a cobalt-rich organic phase, during the first extraction and the second extraction, the mixing time of the extraction is 3 to 10 minutes and the standing time is 20 to 60 minutes.

[0063] As a preferred technical solution, in order to promote the stripping effect and obtain a manganese-rich aqueous phase and a cobalt-rich aqueous phase with higher purity, acid solutions such as sulfuric acid, hydrochloric acid, and nitric acid are used for washing and stripping in this application.

[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 generate unstable cobalt bicarbonate, the ammonium bicarbonate solution used in the present application needs to be excessive, 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, and more preferably 2.2 times or more.

[0065] The following will specifically describe a method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste provided by the present application in combination with examples and recovery data of lanthanum, strontium, manganese and cobalt.

[0066] Example 1

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

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

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

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

[0071] The step of recovering lanthanum hydroxide precipitate comprises: taking 200 mL of lanthanum-containing leaching solution obtained by secondary leaching, heating to 60-70° C., adding sodium hydroxide to pH=12, stirring for reaction for 1 hour, aging for 0.5 hour, filtering to obtain lanthanum hydroxide residue; and washing the lanthanum hydroxide residue with water to pH=7-8.

[0072] The step of recovering lanthanum oxide comprises: drying lanthanum hydroxide and calcining it at a calcination temperature of 750° C. for 2 hours to obtain lanthanum oxide solid.

[0073] The step of recovering sodium lanthanum sulfate double salt precipitate comprises: taking 200 mL of leaching solution, heating to 80° C., adding sodium carbonate until the pH value of the leaching solution is 4.0, then adding 30 g of sodium sulfate to react for 1 hour, 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] According to 25% P204 extractant, add 75% kerosene, that is, 200mL P204 extractant and 600mL kerosene are mixed evenly to prepare P204 organic phase, and then add 33mL 32% liquid alkali for saponification, with a saponification rate of 50% to 60%, mix evenly, and prepare 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 according to O / A=4 / 1, that is, 800mL P204 saponified organic phase / 200mL manganese-cobalt mixed filtrate, mix for 5 minutes, stand for 40 minutes to separate the phases, the upper layer is the P204 manganese-rich 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 90g / L), according to O / A=8 / 1, that is, 800mL P204 manganese-rich organic phase / 100mL hydrochloric acid, mix for 5 minutes, stand for 40 minutes to separate the phases, the upper layer is the organic phase after P204 washing. The lower layer is the water phase;

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

[0079] Take P204 stripping solution (manganese nitrate solution), heat it to 400℃, and calcine it for 2h to obtain manganese dioxide.

[0080] The steps for recovering cobalt oxide include:

[0081] According to 30% P507 extractant, add 70% kerosene, that is, 240mL P507 extractant and 560mL kerosene are mixed evenly to prepare P507 organic phase, and then 32% liquid caustic soda 33mL is added for saponification, the saponification rate is 50%~60%, and mixed evenly to obtain 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, according to O / A=4 / 1, that is, 800mL P507 saponified organic phase / 200mL P204 raffinate, mix for 5 minutes, stand for 45 minutes to separate the phases, the upper layer is P507 cobalt-rich organic phase, and the main component of the lower aqueous phase is sodium sulfate solution;

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

[0084] Take the organic phase after P507 washing and sulfuric acid (concentration 150g / L), according to O / A=8 / 1, that is, 800mL of P507 cobalt-rich organic phase after washing / 100mL of sulfuric acid, mix for 5min, stand for 40min for phase separation, the upper layer is the organic phase after P507 stripping, and the lower layer is the P507 stripping solution, that is, the cobalt sulfate solution;

[0085] Take an excess of 150g / 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 stripping solution (cobalt sulfate solution) at the same time, add for 0.5~2h, adjust pH=8~9, temperature 60℃, age for 2h, filter, wash the filter cake with water to remove sulfate, then dry, and calcine at 700℃ for 4h to obtain cobalt oxide.

[0086] Example 2

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

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

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

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

[0091] The step of recovering lanthanum hydroxide precipitate comprises: taking 200 mL of lanthanum-containing leaching solution obtained by secondary leaching, heating to 60-70° C., adding sodium hydroxide to pH=12, stirring for reaction for 1 hour, aging for 0.5 hour, filtering to obtain lanthanum hydroxide residue; and washing the lanthanum hydroxide residue with water to pH=7-8.

[0092] The step of recovering lanthanum oxide comprises: drying lanthanum hydroxide and calcining it at a calcination temperature of 750° C. for 2 hours to obtain lanthanum oxide solid.

[0093] The step of recovering sodium lanthanum sulfate double salt precipitate comprises: taking 200 mL of leaching solution, heating to 80° C., adding sodium carbonate until the pH value of the leaching solution is 4.0, then adding 30 g of sodium sulfate to react for 1 hour, 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] According to 25% P204 extractant, add 75% kerosene, that is, 200mL P204 extractant and 600mL kerosene are mixed evenly to prepare P204 organic phase, and then add 33mL 32% liquid alkali for saponification, with a saponification rate of 50% to 60%, mix evenly, and prepare 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 according to O / A=4 / 1, that is, 800mL P204 saponified organic phase / 200mL manganese-cobalt mixed filtrate, mix for 5 minutes, stand for 40 minutes to separate the phases, the upper layer is the P204 manganese-rich 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 90g / L), according to O / A=8 / 1, that is, 800mL P204 manganese-rich organic phase / 100mL hydrochloric acid, mix for 5 minutes, stand for 40 minutes to separate the phases, the upper layer is the organic phase after P204 washing. The lower layer is the water phase;

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

[0099] Take P204 stripping solution (manganese nitrate solution), heat it to 400℃, and calcine it for 2h to obtain manganese dioxide.

[0100] The steps for recovering cobalt oxide include:

[0101] According to 30% P507 extractant, add 70% kerosene, that is, 240mL P507 extractant and 560mL kerosene are mixed evenly to prepare P507 organic phase, and then 32% liquid caustic soda 33mL is added for saponification, the saponification rate is 50%~60%, and mixed evenly to obtain 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, according to O / A=4 / 1, that is, 800mL P507 saponified organic phase / 200mL P204 raffinate, mix for 5 minutes, stand for 45 minutes to separate the phases, the upper layer is P507 cobalt-rich organic phase, and the main component of the lower aqueous phase is sodium sulfate solution;

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

[0104] Take the organic phase after P507 washing and sulfuric acid (concentration 150g / L), according to O / A=8 / 1, that is, 800mL of P507 cobalt-rich organic phase after washing / 100mL of sulfuric acid, mix for 5min, stand for 40min for phase separation, the upper layer is the organic phase after P507 stripping, and the lower layer is the P507 stripping solution, that is, the 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 stripping solution (cobalt sulfate solution) at the same time, add for 0.5~2h, adjust pH=8~9, temperature 60℃, age for 2h, filter, wash the filter cake with water to remove sulfate, then dry, and calcine at 700℃ for 4h to obtain cobalt oxide.

[0106] Example 3

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

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

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

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

[0111] The step of recovering lanthanum hydroxide precipitate comprises: taking 200 mL of lanthanum-containing leaching solution obtained by secondary leaching, heating to 60-70° C., adding sodium hydroxide to pH=12, stirring for reaction for 1 hour, aging for 0.5 hour, filtering to obtain lanthanum hydroxide residue; and washing the lanthanum hydroxide residue with water to pH=7-8.

[0112] The step of recovering lanthanum oxide comprises: drying lanthanum hydroxide and calcining it at a calcination temperature of 750° C. for 2 hours to obtain lanthanum oxide solid.

[0113] The step of recovering sodium lanthanum sulfate double salt precipitate comprises: taking 200 mL of leaching solution, heating to 80° C., adding sodium carbonate until the pH value of the leaching solution is 4.0, then adding 30 g of sodium sulfate to react for 1 hour, 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] According to 25% P204 extractant, add 75% kerosene, that is, 200mL P204 extractant and 600mL kerosene are mixed evenly to prepare P204 organic phase, and then add 33mL 32% liquid alkali for saponification, with a saponification rate of 50% to 60%, mix evenly, and prepare 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 according to O / A=4 / 1, that is, 800mL P204 saponified organic phase / 200mL manganese-cobalt mixed filtrate, mix for 5 minutes, stand for 40 minutes to separate the phases, the upper layer is the P204 manganese-rich 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 90g / L), according to O / A=8 / 1, that is, 800mL P204 manganese-rich organic phase / 100mL hydrochloric acid, mix for 5 minutes, stand for 40 minutes to separate the phases, the upper layer is the organic phase after P204 washing. The lower layer is the water phase;

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

[0119] Take P204 stripping solution (manganese nitrate solution), heat it to 400℃, and calcine it for 2h to obtain manganese dioxide.

[0120] The steps for recovering cobalt oxide include:

[0121] According to 30% P507 extractant, add 70% kerosene, that is, 240mL P507 extractant and 560mL kerosene are mixed evenly to prepare P507 organic phase, and then 32% liquid caustic soda 33mL is added for saponification, the saponification rate is 50%~60%, and mixed evenly to obtain 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, according to O / A=4 / 1, that is, 800mL P507 saponified organic phase / 200mL P204 raffinate, mix for 5 minutes, stand for 45 minutes to separate the phases, the upper layer is P507 cobalt-rich organic phase, and the main component of the lower aqueous phase is sodium sulfate solution;

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

[0124] Take the organic phase after P507 washing and sulfuric acid (concentration 150g / L), according to O / A=8 / 1, that is, 800mL of P507 cobalt-rich organic phase after washing / 100mL of sulfuric acid, mix for 5min, stand for 40min for phase separation, the upper layer is the organic phase after P507 stripping, and the lower layer is the P507 stripping solution, that is, the cobalt sulfate solution;

[0125] Take an excess of 200 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 stripping solution (cobalt sulfate solution) at the same time, add for 0.5~2h, adjust pH=8~9, temperature 60℃, age for 2h, filter, wash the filter cake with water to remove sulfate, then dry, and calcine at 700℃ for 4h to obtain cobalt oxide.

[0126] Example 4

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

[0128]

[0129] As can be seen from Table 1, the recovery methods provided in Examples 1-3 of the present application can recover valuable metals such as cobalt, manganese, lanthanum and strontium after the same batch of lanthanum strontium manganese and cobalt waste (including valuable metals 9% cobalt, 28.5% manganese, 33.8% lanthanum, 5.4% strontium and 23.3% cheap metals) is recovered, and the recovery rate is above 92.0%, and the recovery purity is above 95.8%; this shows that the recovery method of lanthanum strontium manganese and cobalt waste provided in Examples 1-3 of the present 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 the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials, characterized in that: Includes steps: Step S1, placing the lanthanum, strontium, manganese and cobalt waste in a mixed solution of sulfuric acid and hydrogen peroxide for one time leaching to obtain a leachate and a leaching residue; Step S2, placing the leached residue in a hydrochloric acid solution for secondary leaching to obtain a lanthanum-containing leaching solution and strontium sulfate leaching residue; Step S3, adding an alkaline reagent to the lanthanum-containing leachate to perform a first precipitation reaction and then filtering to obtain a lanthanum hydroxide precipitate; Step S4, adding sodium sulfate to the leachate to carry out double salt reaction and then filtering to obtain sodium sulfate lanthanum double salt precipitate and manganese-cobalt mixed filtrate; Step S5, adding a first acidic phosphorus-containing organic extractant to the manganese-cobalt mixed filtrate for a first extraction to obtain a manganese-rich organic phase and a cobalt-rich aqueous phase; Step S6, adding an acid solution to the manganese-rich organic phase for a first washing and a first stripping, and then calcining the manganese-rich aqueous phase to obtain manganese oxide; Step S7, adding 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, adding an acid solution to the cobalt-rich organic phase for a second washing and a second stripping to obtain a cobalt-rich aqueous phase; Step S9, subjecting the sodium bicarbonate solution in the cobalt-rich aqueous phase to a second precipitation reaction, filtering the solution, and calcining and filtering the precipitate to obtain cobalt oxide.

2. A method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials according to claim 1, characterized in that: 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.

3. The method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials according to claim 1, characterized in that: After step S3, the method further includes the step of calcining the lanthanum hydroxide precipitate to obtain lanthanum oxide.

4. The method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials according to claim 1, characterized in that: In step S1, during the primary 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. The method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials 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-to-solid ratio of the hydrochloric acid solution to the leached residue is 2-8:

1.

6. A method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials 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 water, and the pH of the reaction is 10-14.

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

8. The method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials according to claim 1, characterized in that: In step S5 or S7, the mixing time of the extraction is 3 to 10 minutes, and the standing time is 20 to 60 minutes.

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

10. The method for recovering lanthanum, strontium, manganese and cobalt from lanthanum, strontium, manganese and cobalt waste materials 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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