Method for recovering lithium from waste saggar

Abstract

A method for recovering lithium from waste saggar, according to the present invention, comprises the steps of: causing waste saggar to come contact with a salt solution; recovering the waste saggar that has come in contact with the salt solution, and thermally treating the recovered waste saggar at a temperature of 950℃ or higher; separating a waste saggar damaged layer from the thermally treated waste saggar; and recovering lithium from the separated waste saggar damaged layer.

Description

Method for recovering lithium from waste metals

[0001] The present invention relates to a method for recovering lithium from waste lithium, and more particularly, to a method for effectively separating and recovering lithium from waste lithium that is discarded after being used in the production of a cathode active material.

[0002] The cathode active material of a lithium secondary battery is manufactured by firing salts of lithium, cobalt, nickel, manganese, etc. at high temperatures in a refractory material mainly composed of silicon, aluminum, and magnesium oxide.

[0003] At this time, the raw material of the positive electrode active material can react with the surface of the refractory, and as the refractory is used repeatedly, the surface of the refractory is eroded and deteriorated due to the raw material of the positive electrode active material, so it must be discarded after a certain number of uses.

[0004] Therefore, lithium-containing parts exist in waste metallurgy bottles discarded after repeated use, and a method for efficiently separating these parts is required.

[0005] Traditionally, lithium recovery from spent smelting has involved crushing the entire smelting, followed by roasting, acid treatment, and other processes to extract the lithium. However, this process involves high processing costs, as even the portions with low lithium content are added to the process.

[0006] Therefore, there is a need to develop a method for selectively recovering only the lithium-containing portion of the endocardium.

[0007] The present invention aims to provide a method for recovering lithium from waste slag, which can efficiently separate and recover a lithium-containing portion from the waste slag.

[0008] The present invention provides a method for recovering lithium from waste sphagnum, comprising the steps of: contacting waste sphagnum with a salt solution; recovering the waste sphagnum contacted with the salt solution and heat-treating the recovered waste sphagnum at a temperature of 950°C or higher; separating a waste sphagnum deteriorated layer from the heat-treated waste sphagnum; and recovering lithium from the separated waste sphagnum deteriorated layer.

[0009] The method for recovering lithium from waste cellulose according to the present invention has the advantage of reducing processing costs because it separates a deteriorated layer containing lithium from waste cellulose discarded after manufacturing a cathode active material and then recovers lithium therefrom.

[0010] In addition, lithium can be recovered and recycled from waste metallurgy, which is desirable from an environmental perspective and has the advantage of reducing waste metallurgy.

[0011] Figure 1 is an image showing a cross-section of the pulmonary artery.

[0012] FIG. 2 is an image showing a specimen of a pulmonary artery according to some embodiments of the present invention.

[0013] Figures 3 to 5 are images schematically illustrating the detached portion and the non-detachable area in the top view, side view, and top view photographs of the portion that did not pass through the vibrator in the pulmonary fibrosis specimen according to the experimental example.

[0014] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention. The present invention is defined solely by the scope of the claims set forth below.

[0015] In the present invention, when it is said that a member is located “on” another member, this includes not only cases where a member is in direct contact with another member, but also cases where another member is interposed between the two members.

[0016] When a part of the present invention is said to "include" a certain component, this does not mean that other components are excluded, but rather that other components may be included, unless otherwise specifically stated.

[0017]

[0018] One aspect of the present invention relates to a method for recovering lithium from waste sphagnum, comprising the steps of: contacting waste sphagnum with a salt solution; recovering the waste sphagnum contacted with the salt solution, and heat-treating the recovered waste sphagnum at a temperature of 950°C or higher; separating a waste sphagnum deteriorated layer from the heat-treated waste sphagnum; and recovering lithium from the separated waste sphagnum deteriorated layer.

[0019] The method for recovering lithium from a waste metallurgy according to the present invention has the advantage of efficiently recovering lithium because it separates the deteriorated layer by weakening the adhesion at the interface between the deteriorated layer and the non-deteriorated layer, and recovers lithium by roasting and acid-treating it.

[0020]

[0021] Referring to Figure 1, it can be seen that the refractory layer has different properties. Specifically, the area where the positive electrode active material is manufactured can be divided into a degraded layer containing a large amount of lithium, which has been degraded as lithium raw materials are deposited, and a non-degraded layer corresponding to the original refractory layer.

[0022] Table 1 below shows the main components (unit: weight%) of the altered layer and the non-altered layer (existing refractory), and it can be confirmed that the altered layer contains a large amount of lithium.

[0023] The main mineral phases of the above-mentioned altered layer were LiAlO2 and Li4SiO4 containing lithium.

[0024]

[0025] Item LiAlSiMg modified layer (lithium-containing) 3.002 2.98.15 3.94 Non-modified layer (conventional refractory) 0.083 4.61 0.67.31

[0026] In the present invention, a deteriorated layer containing a large amount of lithium is separated from the non-deteriorated layer, and lithium is recovered.

[0027]

[0028] A method for recovering lithium from a waste metallurgical device according to the present invention comprises the step of contacting the waste metallurgical device with a salt solution.

[0029] The refractory material is composed of a porous material. When the refractory material is brought into contact with the salt solution, the salt solution is absorbed into the porous refractory material. When heat-treated at a temperature of 950°C or higher, as described below, the adhesion between the denatured layer and the non-denatured layer can be weakened.

[0030] The step of contacting the above-mentioned endocardium with the above-mentioned salt solution; may further include, but is not limited to, the step of cutting the above-mentioned endocardium beforehand.

[0031] If the step of cutting the above-mentioned endocardium is further included, contact between the above-mentioned endocardium and the salt solution becomes smoother, which is preferable from a process perspective.

[0032]

[0033] In one embodiment of the present invention, the salt solution may include one or more compounds selected from the group consisting of alkali compounds and alkaline earth compounds.

[0034] For example, the salt solution may include at least one selected from the group consisting of sodium chloride, potassium chloride, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, calcium chloride, calcium nitrate, calcium sulfate, magnesium chloride, magnesium nitrate, magnesium sulfate, disodium phosphate, barium chloride, trisodium phosphate, sodium silicate, potassium sulfide, sodium sulfite, zinc sulfate, aluminum chloride, and sodium sulfate.

[0035] Specifically, the salt solution may be a solution in which one or more compounds selected from the group consisting of the alkaline compounds and alkaline earth compounds that are easily soluble in water are dissolved in water.

[0036] In another embodiment of the present invention, the salt solution may include sodium silicate.

[0037] Specifically, the salt solution may include a water glass solution.

[0038]

[0039] In another embodiment of the present invention, at least one compound selected from the group consisting of the alkaline compound and the alkaline earth compound may be included in an amount of 3 wt% or more, preferably 7 wt% or more, and more preferably 10 to 20 wt%, based on 100 wt% of the total salt solution.

[0040] When at least one compound selected from the group consisting of the alkaline compound and the alkaline earth compound is included within the above range, the salt solution effectively penetrates the pulmonary cyst, so that in the step of separating the pulmonary cyst deterioration layer from the pulmonary cyst, which will be described later, the separation of the pulmonary cyst deterioration layer can be easily achieved, which is preferable.

[0041]

[0042] In another embodiment of the present invention, the step of contacting the pulmonary artery with a salt solution may be immersing the pulmonary artery in the salt solution.

[0043] The above immersion can be performed by completely submerging the lung cancer cell in the salt solution, and can be performed for 10 to 90 minutes, preferably 20 to 60 minutes, and more preferably 20 to 40 minutes, but is not limited thereto.

[0044] If the above immersion time is within the above range, sufficient penetration of the salt solution is possible, which is preferable.

[0045]

[0046] In another embodiment of the present invention, the salt solution may be applied to the surface of the pulmonary artery.

[0047] The above application may be performed by one or more methods selected from the group consisting of, but not limited to, brush application, spray coating, knife casting, and doctor blade.

[0048] The amount of the salt solution applied is not limited. However, the salt solution applied may be applied in an amount sufficient to penetrate the pulmonary artery.

[0049] The above application may be performed multiple times, but is not limited thereto.

[0050]

[0051] The method for recovering lithium from waste metallurgy according to the present invention includes the steps of recovering the waste metallurgy that has come into contact with the salt solution and heat-treating the recovered waste metallurgy at a temperature of 950°C or higher.

[0052] The main mineral phase of the above-mentioned altered layer is LiAlO2, Li4SiO4, etc. containing lithium, but the altered layer and the non-altered layer are strongly attached to each other, so there is a problem that it is somewhat difficult to separate the altered layer from the non-altered layer by mechanical impact alone.

[0053] Therefore, the method for recovering lithium from the waste slag according to the present invention recovers the waste slag that has come into contact with the salt solution, and heat-treats the recovered waste slag at a temperature of 95°C or higher, thereby weakening the adhesion of the interface between the altered layer and the non-altered layer.

[0054]

[0055] In another embodiment of the present invention, the heat treatment can be performed at a temperature of 1,000 to 1,500°C.

[0056] In another embodiment of the present invention, the heat treatment can be performed at a temperature of 1,000 to 1,300°C.

[0057] When the above heat treatment is performed within the above range, it is preferable to minimize the heat treatment time while maximizing the phenomenon of weakening the adhesion of the interface between the altered layer and the non-altered layer.

[0058]

[0059] In another embodiment of the present invention, the step of heat-treating the recovered lung cancer cells at a temperature of 950°C or higher may be performed for 30 minutes to 3 hours, preferably 40 minutes to 2 hours and 30 minutes, and more preferably 40 minutes to 1 hour.

[0060] When the above heat treatment is performed within the above time range, it is preferable that the separation of the denatured layer ...

[0061]

[0062] The above heat treatment may be performed in an electric furnace or a sintering furnace, but is not limited thereto.

[0063]

[0064] In another embodiment of the present invention, the method may further include a step of heat-treating the recovered waste urea at a temperature of 950°C or higher; and a step of cooling the heat-treated waste urea.

[0065] The above cooling may be, but is not limited to, cooling to room temperature.

[0066]

[0067] The method for recovering lithium from waste metallurgy according to the present invention includes a step of separating the waste metallurgy deteriorated layer from the heat-treated waste metallurgy.

[0068] In another embodiment of the present invention, the step of separating the deteriorated layer of the heat-treated endocarp from the non-deteriorated layer of the endocarp may include the step of separating the deteriorated layer of the endocarp from the non-deteriorated layer of the endocarp using at least one selected from the group consisting of a crusher, a shearer, and a vibrator.

[0069] Specifically, the method for recovering lithium from waste metal according to the present invention can separate the altered layer of waste metal from the unaltered layer of waste metal by applying a physical force to the heat-treated waste metal.

[0070] Preferably, the step of separating the denatured layer of the heat-treated endocarp from the endocarp can be performed using the vibrator.

[0071] The above vibrator may specifically be a vibrating sieve.

[0072]

[0073] In another embodiment of the present invention, the step of separating the altered layer of the heat-treated endocarp from the altered layer of the heat-treated endocarp may include a step of separating the altered layer of the heat-treated endocarp from the unaltered layer of the heat-treated endocarp by sieving.

[0074] The above sieving can be performed with a sieve having holes of 3 to 15 mm in diameter, preferably 5 to 13 mm, and more preferably 7 to 10 mm.

[0075] By passing through the hole of the above size, only the altered layer of the pulmonary spleen separated from the non-altered layer of the pulmonary spleen can be separated.

[0076]

[0077] The above constitution may be a vibration constitution using a vibration constitution machine, but is not limited thereto.

[0078] The step of separating the altered layer of the pulmonary vascular tissue from the heat-treated pulmonary vascular tissue and the step of separating the altered layer of the pulmonary vascular tissue by sieving the non-altered layer of the pulmonary vascular tissue may be performed simultaneously, but are not limited thereto.

[0079] For example, the heat-treated endocarp specimen may be placed on the sieve and vibrated using the vibrator for 5 to 20 minutes, specifically 8 to 15 minutes, and more specifically 8 to 10 minutes, thereby sieving and separating the endocarp deteriorated layer, but the present invention is not limited thereto.

[0080] In another embodiment of the present invention, the separated endocarp deterioration layer may have a lithium content of 1.0 wt% or more based on the total weight of the separated endocarp deterioration layer.

[0081]

[0082] The method for recovering lithium from a waste metallurgical product according to the present invention comprises a step of recovering lithium from a separated waste metallurgical product deterioration layer.

[0083] The step of recovering lithium from the above-mentioned endolithic layer may further include, but is not limited to, a step of crushing the above-mentioned endolithic layer, if necessary.

[0084] For example, the above-mentioned endocardial effluent layer can be crushed using a crusher and then treated with acid.

[0085] The above crusher may include, but is not limited to, a sample mill, a hammer mill, a pin mill, a wing mill, a tornado mill, a hammer crusher, etc.

[0086]

[0087] Methods for recovering lithium from the above-mentioned endolithic layer may include, but are not limited to, acid leaching, hydrothermal method, sulfuric acid roasting method, etc.

[0088] For example, by going through the step of discharging the above-mentioned endolithic layer, lithium can be converted into a form such as lithium oxide, lithium carbonate, or lithium hydroxide.

[0089] The above-described calcining step may be a heat treatment of the oxidized layer of the lung enamel at a temperature of 550 to 650°C for 1 to 4 hours. When the above-described calcining step is performed within the above-described temperature range, it is preferable because the lithium compound contained within the oxidized layer of the lung enamel is sufficiently transformed into a form that is easily soluble in water or an acidic solution during the acid treatment described later.

[0090] The above-mentioned firing step may be performed in a rotary kiln, an electric furnace, etc., and may be performed in an air atmosphere, but is not limited thereto.

[0091]

[0092] In addition, lithium can be recovered by dissolving lithium contained in the endolithic oxidized layer by contacting the endolithic oxidized layer with an acidic solution, but is not limited thereto.

[0093] The above acidic solution can be used by adding an acid such as sulfuric acid to tap water, industrial water, distilled water, purified water, ion-exchanged water, pure water, ultrapure water, etc.

[0094] The concentration of the above acidic solution can be adjusted so that the pH when lithium is dissolved satisfies 7 to 10.

[0095] Lithium can be recovered by dissolving the lithium and then precipitating it, but is not limited thereto.

[0096]

[0097] The method of recovering lithium from waste slag according to the present invention does not crush the entire waste slag and then recover lithium therefrom, but selectively separates only the altered layer containing lithium and then recovers lithium therefrom, so it has an excellent advantage of being able to efficiently separate and recover lithium compared to the case where the entire waste slag is crushed and then lithium is recovered therefrom.

[0098]

[0099] Hereinafter, preferred embodiments and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0100]

[0101] Manufacturing example

[0102] Using sodium silicate solution (water glass) (purity: SiO2 35%, Na2O 17%), 500 g of three different concentrations of sodium silicate solution (water glass) were prepared, named WG1, WG2, and WG3 as shown in Table 2.

[0103]

[0104] Composition WG1 WG2 WG3 Mixing ratio (g) Sodium silicate solution 50 100 150 Distilled water 450 400 350

[0105] Experimental example

[0106] The pulmonary artery was cut to produce a square specimen measuring approximately 3 cm × 3 cm, as shown in Fig. 2.

[0107] Afterwards, each specimen was placed in a beaker, completely submerged in the sodium silicate solution prepared according to the manufacturing example, and immersed for 30 minutes.

[0108] After immersion, the specimens were removed from the beaker and heated in an electric furnace at a heating rate of 10°C per minute at temperatures (800°C, 900°C, 1,000°C) according to Table 3 below for 1 hour each, and then cooled in the furnace. At this time, for comparison, a specimen (WG0) that was not to be immersed in the solution was also heat-treated in the same manner.

[0109] The cooled specimen was placed on a 9.5 mm sieve and vibrated for 10 minutes in a vibrating sieve (vibration sieve). The detached portion and non-detachment area in the top view, side view, and top view photographs of the portion that did not pass through the sieve were diagrammed in Figures 3 to 5.

[0110] Additionally, the weight and fraction of the portion that did not pass through the vibrator and the portion that did pass through the vibrator were measured for each specimen and are shown in Table 3 below.

[0111]

[0112] Temperature (℃) Item Specimen weight and fraction WG0 WG1 WG2 WG3 Weight (g) % Weight (g) % Weight (g) % Weight (g) % 1,000 Sieve passing fraction (altered layer) 4.5 8.25.19.8 14.9 26.5 11.7 24.9 Sieve passing fraction 49.89 1.84 6.3 90.24 1.5 73.5 3 5.1 75.1 Total 54.3 100.0 51.3 100.0 56.4 100.0 46.7 100.0 9 Sieve passing fraction (altered layer) 1.5 2.9 2.8 5.9 2.25.21.3 2.5 Sieve passing fraction 50.5 9 7.14 5.394.141.294.850.197.5Total 52.1100.048.2100.043.5100.051.4100.0800Sieved portion (spoiled layer) 1.12.22.65.92.96.01.83.4Unsieved portion 46.697.842.194.146.394.050.696.6Total 47.6100.044.7100.049.2100.052.3100.0

[0113] Figure 3 illustrates top-down, side-down, and top-down views of the portion that did not pass through the vibrator after heat treatment at 800°C, as well as the detached portion and non-detached region. It can be seen that the lithium-containing altered layer was hardly detached in both the specimen not immersed in the solution (WG0) and the specimens WG1, WG2, and WG3 with different water glass concentrations.

[0114] Figure 4 illustrates top-view, side-view, and top-view photographs of the portion that did not pass through the vibrator after heat treatment at 900°C, illustrating the detached portion and non-detached region. It can be seen that the lithium-containing altered layer was hardly detached in the non-solution-immersed specimen (WG0) and in WG1, WG2, and WG3, which had different water glass concentrations.

[0115] Figure 5 illustrates the detached portions and non-detached areas in top, side, and top views of the portions that did not pass through the vibrator after heat treatment at 1,000°C. It can be seen that the non-solution-immersed specimens (WG0) and WG1 specimens have slightly more detached portions than the 800°C and 900°C specimens. On the other hand, it can be seen that all portions of the WG2 and WG3 specimens have detached.

[0116] Referring to Table 3, it can be seen that the sieve passing rate of the specimens immersed in WG2 and WG3 solutions and then heat-treated at 1,000°C was approximately 25%, indicating that most of the altered layer containing lithium was removed.

[0117] Therefore, it can be seen that when the lung lining is immersed in a salt solution of a certain concentration and then heat-treated at 1,000°C or higher, the altered layer containing lithium can be easily detached (separated) from the non-altered layer by vibration.

[0118]

[0119] The present invention is not limited to the above-described embodiments, but can be manufactured in a variety of different forms. Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A step of bringing the lung tissue into contact with a salt solution; A step of recovering the lung cancer cells that have come into contact with the salt solution and heat-treating the recovered lung cancer cells at a temperature of 950°C or higher; A step of separating the denatured layer of the lung lining from the heat-treated lung lining; and A step of recovering lithium from the separated endothelium-containing deteriorated layer; A method for recovering lithium from a waste gasket containing lithium.

2. In paragraph 1, The step of separating the denatured layer of the lung lining from the heat-treated lung lining; A method for recovering lithium from waste metallurgy, comprising the step of separating the deteriorated layer of waste metallurgy from the non-deteriorated layer of waste metallurgy using at least one selected from the group consisting of a crusher, a shearer, and a vibrator.

3. In paragraph 1, A method for recovering lithium from a waste metal, wherein the salt solution comprises at least one compound selected from the group consisting of alkaline compounds and alkaline earth compounds.

4. In paragraph 3, A method for recovering lithium from a waste metallurgical product, wherein at least one compound selected from the group consisting of the alkaline compounds and alkaline earth compounds is contained in an amount of 3 wt% or more with respect to 100 wt% of the entire salt solution.

5. In paragraph 1, A method for recovering lithium from a waste metallurgical device, wherein the salt solution contains sodium silicate.

6. In paragraph 1, The step of contacting the above-mentioned pulmonary edema with a salt solution; A method for recovering lithium from a waste metallurgical device, comprising immersing the waste metallurgical device in a salt solution.

7. In paragraph 1, The step of contacting the above-mentioned pulmonary edema with a salt solution; A method for recovering lithium from a closed cell, comprising applying the salt solution to the surface of the closed cell.

8. In paragraph 1, In the step of heat treating the above-mentioned lung cancer cell, A method for recovering lithium from waste metallurgy, wherein the heat treatment is performed at a temperature of 1,000 to 1,500°C.

9. In paragraph 8, In the step of heat treating the above-mentioned lung cancer cell, A method for recovering lithium from waste metallurgy, wherein the heat treatment is performed at a temperature of 1,000 to 1,300°C.

10. In paragraph 1, A method for recovering lithium from waste metal oxide, wherein the step of heat-treating the recovered waste metal oxide at a temperature of 950°C or higher is performed for 30 minutes to 3 hours.

11. In paragraph 1, A step of heat-treating the recovered lung cancer at a temperature of 950°C or higher; thereafter A method for recovering lithium from waste metallurgy, further comprising the step of cooling the heat-treated waste metallurgy.

12. In paragraph 2, The step of separating the denatured layer of the lung lining from the heat-treated lung lining; A method for recovering lithium from waste cellulose, comprising the step of separating the non-alkali layer and the altered layer of waste cellulose by sieving.

13. In paragraph 1, A method for recovering lithium from waste cellulose, wherein the separated waste cellulose layer has a lithium content of 1.0 wt% or more with respect to the total weight.

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