Method for recovering lithium from waste saggar

Abstract

Provided is a method for recovering lithium from a waste sagger, comprising the steps of: pulverizing a waste sagger; and mixing the pulverized waste sagger with a sulfuric acid solution and leaching lithium so as to obtain a sulfuric acid leachate, wherein the step of obtaining the sulfuric acid leachate allows lithium to be leached at pH 4.0 to 12.0.

Description

Method for recovering lithium from waste refractory casings

[0001] The present invention relates to a method for recovering lithium from waste refractory plates.

[0002] To manufacture a composite oxide of lithium and a transition metal as an anode active material, raw materials containing compounds including lithium or transition metals can be loaded into a sagger, which is a firing vessel, and fired at a high temperature. Discarded saggers after use contain lithium-containing compounds that have detached from the raw materials during the manufacture of the anode active material.

[0003] The objective of the present invention is to provide a method for efficiently recovering lithium from waste refractory casings.

[0004] The objective of the present invention is to provide a method for efficiently recovering high-purity lithium from waste refractory casings.

[0005] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0006] In one embodiment of the present invention, a method for recovering lithium from waste refractory ware comprises the steps of: crushing waste refractory ware; and mixing a sulfuric acid solution with the crushed waste refractory ware to leach lithium and obtain a sulfuric acid leachate; wherein the step of obtaining the sulfuric acid leachate leachates lithium at a pH of 4.0 to 12.0.

[0007] In the above method for recovering lithium from waste refractory plates, the concentration of the sulfuric acid solution can be adjusted so that the pH is 4.0 to 12.0.

[0008] The concentration of the above sulfuric acid solution may be 0.6 wt% to 1.2 wt%.

[0009] The sulfuric acid solution can be mixed with the crushed waste refractory casing in an amount such that the weight ratio of the waste refractory casing to the sulfuric acid solution is 1:2 to 12.

[0010] In one embodiment, the content of lithium leached in the sulfuric acid leaching solution may be 1.0 g / L to 3.0 g / L.

[0011] In one embodiment, the content of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn in the sulfuric acid leachate may be 0.3 g / L to 1.0 g / L.

[0012] In one embodiment, the mass ratio of the Li content to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn in the sulfuric acid leachate may be 2.000 to 2.550.

[0013] In one embodiment, the Si content in the sulfuric acid leaching solution may be 3.75 g / L or less.

[0014] In one embodiment, the content of Al in the sulfuric acid leachate may be 0.09 g / L or less.

[0015] In one embodiment, the content of Mg in the sulfuric acid leachate may be 0.3 g / L or less.

[0016] In one embodiment, the content of Ca in the sulfuric acid leachate may be 0.022 g / L or less.

[0017] In one embodiment, the content of Ni in the sulfuric acid leachate may be 0.015 g / L or less.

[0018] In one embodiment of the present invention, a sulfuric acid leaching solution of waste refractory armor is provided, wherein the mass ratio of the content of Li to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn is 2.000 to 2.550.

[0019] The lithium content in the sulfuric acid leachate of the above waste refractory armor may be 0.3 g / L to 1.0 g / L.

[0020] The sulfuric acid leachate of the above waste refractory armor can be obtained by leaching with sulfuric acid at a pH of 4.0 to 12.0.

[0021] The sulfuric acid leachate obtained from the above method for recovering lithium from waste refractory plates has a reduced concentration of impurities and a high lithium recovery rate.

[0022] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below.

[0023] Figure 1 is a graph showing the Li concentration in the sulfuric acid leachate of waste refractory metals according to pH changes.

[0024] Figure 2 is a graph showing the concentrations of Si and Al in the sulfuric acid leachate of waste refractory metals according to changes in pH.

[0025] Figure 3 is a graph showing the concentrations of Mg and Fe in the sulfuric acid leachate of waste refractory metals according to changes in pH.

[0026] Figure 4 is a graph showing the concentrations of Ca, Ni, and Mn in the sulfuric acid leachate of waste refractory metals according to changes in pH.

[0027] Figure 5 is a graph showing the calculated values ​​of lithium concentration and impurity Si+Al+Mg+Fe+Ca+Fe+Ni+Mn concentration in the sulfuric acid leachate of waste refractory metal as a function of pH change.

[0028] Figure 6 is a graph showing the Li leaching rate (wt%) of the sulfuric acid leachate of waste refractory metal as a function of pH change.

[0029] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0030] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0031] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0032] In this specification, lithium, sulfur, magnesium, calcium, sodium, potassium, etc., may be in a form that exists in raw materials, extracts, or precipitates, and are collectively referred to as types of elements without being limited to a specific form, such as metal atoms, atoms, ions, or salts, and when distinction is necessary, they may be understood as being in a state that exists according to the laws of nature.

[0033] In one embodiment of the present invention:

[0034] Step of crushing waste refractory plates; and

[0035] The method comprises the step of mixing a sulfuric acid solution with the crushed waste refractory casing to leach lithium and obtain a sulfuric acid leachate;

[0036] The step of obtaining the above sulfuric acid leachate involves leaching lithium at a pH of 4.0 to 12.0.

[0037] A method for recovering lithium from waste refractory plates is provided.

[0038] High-purity lithium can be efficiently recovered from waste refractory casings by the above method of recovering lithium from waste refractory casings.

[0039] In the method for recovering lithium from the above-mentioned waste refractory, lithium is leached with sulfuric acid. Since impurities are leached along with lithium when the crushed waste refractory is leached with sulfuric acid, the impurities leached along with it are subject to removal in subsequent processes; therefore, if less impurity is leached during leaching, it becomes advantageous for extracting high-purity lithium compounds.

[0040] When leaching the above-mentioned waste refractory casing with sulfuric acid, the degree of leaching varies depending on the pH conditions, and furthermore, the degree of leaching according to pH conditions differs between the case of lithium and other impurities. The method for recovering lithium from the above-mentioned waste refractory casing utilizes different pH conditions between lithium and impurities and includes a configuration for leaching at a predetermined pH of 4.0 to 12.0, which is advantageous for lithium recovery while relatively reducing the leaching of impurities.

[0041] The aforementioned waste refractory casing is alkaline even when leached with water alone. Therefore, when sulfuric acid is mixed with the crushed waste refractory casing, the pH decreases. Although the leaching amount of lithium and impurities may increase as the pH decreases, the increase in the leaching amount of lithium is not significant even if the pH drops below 4.0. On the other hand, if the pH drops below 4.0, the increase in the leaching amount of impurities becomes steep. From these results, it is understood that the sulfuric acid added to lower the pH to below 4.0 contributes almost entirely to the extraction of impurities rather than lithium. Meanwhile, if the pH exceeds 12.0, the leaching amount of impurities decreases, but the leaching amount of lithium also decreases; therefore, the pH must be 12.0 or lower to ensure a certain amount of lithium extraction.

[0042] Therefore, the method for recovering lithium from the above-mentioned waste refractory casing can be carried out under conditions that prevent a significant increase in the leaching of impurities by setting the pH condition to 4.0 or higher, thereby abandoning an increase in the low recovery rate of lithium, and also by setting the pH condition to 12.0 or lower, thereby securing a predetermined amount of lithium extraction.

[0043] In one embodiment, the step of obtaining the sulfuric acid leachate may leach lithium at a pH of 4.0 to 11.0, specifically, a pH of 5.5 to 10.0, more specifically, a pH of 6.0 to 9.0.

[0044] In the method for recovering lithium from the above-mentioned waste refractory plate, the concentration of the sulfuric acid solution can be adjusted to create a leaching environment of pH 4.0 to 12.0, specifically pH 4.0 to 11.0, more specifically pH 5.5 to 10.0, and more specifically pH 6.0 to 9.0.

[0045] In one embodiment, the concentration of the sulfuric acid solution may be 0.6 wt% to 1.2 wt%. The sulfuric acid leachate of waste refractory armor leached with a sulfuric acid solution of the above concentration reduces the concentration of impurities and has a high lithium recovery rate.

[0046] A method for recovering lithium from waste refractory casings according to one embodiment is a method for efficiently recovering high-purity lithium from waste refractory casings. When using a sulfuric acid solution of the above concentration, the sulfuric acid solution can be mixed with the crushed waste refractory casings in an amount such that the weight ratio of the waste refractory casings to the sulfuric acid solution is 1:2 to 12. By mixing the sulfuric acid solution with the crushed waste refractory casings in a weight ratio within the above numerical range, leaching can be performed at a predetermined pH, and the sulfuric acid leachate obtained therefrom has a reduced concentration of impurities and a high lithium recovery rate.

[0047] In one embodiment, based on 10 g of waste refractory plate, the content of lithium leached in the sulfuric acid leaching solution may be 1.0 g / L to 3.0 g / L, specifically 1.1 g / L to 1.5 g / L.

[0048] In one embodiment, the content of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn in the sulfuric acid leachate may be 0.3 g / L to 1.0 g / L.

[0049]

[0050] As described above, by leaching the sulfuric acid leaching solution within a predetermined pH range, the concentration of impurities is reduced and the lithium recovery rate is high, so the ratio of Li content to impurities such as Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn can be high.

[0051] In one embodiment, the mass ratio of the Li content to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn in the sulfuric acid leachate may be 2.000 to 2.550.

[0052] Specifically, the Si content in the above sulfuric acid leaching solution may be 3.75 g / L or less.

[0053] Specifically, the Al content in the above sulfuric acid leachate may be 0.09 g / L or less.

[0054] Specifically, the Mg content in the sulfuric acid leachate may be 0.3 g / L or less.

[0055] Specifically, the Ca content in the sulfuric acid leachate may be 0.022 g / L or less.

[0056] Specifically, the Ni content in the sulfuric acid leachate may be 0.015 g / L or less.

[0057]

[0058] In one embodiment of the present invention, a sulfuric acid leaching solution of waste refractory armor is provided, wherein the ratio of the content of Li to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn is 2.000 to 2.550.

[0059] The sulfuric acid leachate of the above-mentioned waste refractory can be obtained by the method of recovering lithium from the aforementioned waste refractory. Accordingly, the detailed description regarding the sulfuric acid leachate of the above-mentioned waste refractory is as described above.

[0060] Lithium can be obtained by leaching lithium from the waste refractory plate with sulfuric acid at a sulfuric acid leachate of the waste refractory plate at a pH of 4.0 to 12.0, specifically, a pH of 4.0 to 11.0, more specifically, a pH of 5.5 to 10.0, and more specifically, a pH of 6.0 to 9.0.

[0061] In one embodiment, the lithium content in the sulfuric acid leachate of the waste refractory plate may be 1.0 g / L to 3.0 g / L, specifically 1.1 g / L to 1.5 g / L.

[0062]

[0063] Examples and comparative examples of the present invention are described below. The following examples are merely embodiments of the present invention, and the present invention is not limited to the following examples.

[0064]

[0065] (Example)

[0066] The composition of the powder obtained by crushing waste refractory plates was analyzed. The results of the composition analysis of the waste refractory plates are listed in Table 1 below.

[0067] Units (wt%) LiAlCaFeKMgMnSiNaSTiPZrSrBa 1.4930.70.130.600.0436.100.01917.20.120.0790.350.0200.0220.0030.003

[0068] 10g of the above-mentioned crushed waste refractory was leached with a sulfuric acid solution. The pH conditions during leaching were varied while adding sulfuric acid solutions with concentrations ranging from 0.4wt% to 3.6wt%, and the content of Li and various impurity elements in the sulfuric acid leachate was analyzed by component under each pH condition. Waste refractory powder : sulfuric acid solution was mixed in a ratio of 1 : 10 (w:v) and leached at room temperature for 2 hours.

[0069] The results of the analysis of the content of Li and various impurity elements by component in the sulfuric acid leaching solution are listed in Tables 2 and 3 below. From the analysis results, the Li leaching rate (wt%) and the mass ratio of the Li content to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn were calculated and listed in Table 4.

[0070]

[0071] Unit (g / L) pH Sulfuric Acid Concentration (wt%) Li S Ca M g K Na Comparative Example 1 1 2.5 0.4 1.2 2 6 1.4 7 5 Not Detected Not Detected Not Detected 0.01 3 Example 1 1 1.7 0.6 1.1 9 5 2.1 8 0 0.00 3 0.01 8 0.00 3 0.01 3 Example 2 1 0.1 0.7 1.1 3 4 2.3 4 5 0.00 4 0.01 9 0.00 3 0.01 2 Example 3 8.1 0.8 1.1 7 4 2.5 5 0 0.00 8 0.09 0 0.00 4 0.01 2 Example 4 6.2 1.01 3 4 0 3.2 5 5 0.01 8 0.2 2 3 0.00 5 0.01 3 Example 54.11.21.4313.7330.0200.2970.0050.014 Comparative Example 23.61.81.5065.6740.0240.3230.0070.016 Comparative Example 31.92.41.5547.5650.0270.4470.0080.018 Comparative Example 41.13.01.5739.4120.0280.4600.0080.018 Comparative Example 50.73.61.62811.8370.0300.4770.0090.020

[0072] Unit (g / L) pH Sulfuric Acid Concentration (wt%) SiAlFeNiMnTi Comparative Example 1 12.5 0.4 0.7 3 7 0.07 8 0.007 Not Detected Not Detected Not Detected Example 1 11.7 0.6 0.4 7 6 0.06 4 0.011 Not Detected Not Detected Not Detected Example 2 1 0.10 7 0.3 2 7 0.08 9 0.012 Not Detected Not Detected Not Detected Example 38.10 8 0.3 0 4 0.05 9 0.003 Not Detected Not Detected Not Detected Example 46.21 0.00 24 9 0.00 4 0.06 10.005 Not Detected Not Detected Example 5 4.11 20.24 3 0.04 3 0.08 10.011 Not Detected Not Detected Comparative Example 23.6 1.8 0.70 11.16 90.10 70.016 Not detected 0.00 3 Comparative Example 31.9 2.4 1.13 5 1.72 70.13 00.03 30.00 30.01 4 Comparative Example 41.13.01 68 1.80 40.13 00.03 70.00 30.02 3 Comparative Example 50.73 61.17 31.88 10.13 40.03 90.00 30.025

[0073] pH Li Leaching Rate (wt%) Li / (Si+Al+Mg+Fe+Ca+Fe+Ni+Mn) Converted to Mass Ratio Concentration Comparative Example 1 12.5 73.8 1.491 Example 1 11.7 71.9 2.089 Example 2 10.16 8.22.514 Example 38.17 0.7 2.530 Example 46.28 0.6 2.393 Example 54.18 6.12.059 Comparative Example 23.69 0.6 0.644 Comparative Example 31.99 3.5 0.444 Comparative Example 41.19 4.7 0.433 Comparative Example 50.79 8.00.436

[0074] FIGS. 1 to 4 are graphs showing the component analysis results of Examples 1-5 and Comparative Examples 1-5 so as to compare them according to pH changes, and FIGS. 2 to 4 are classified and shown according to the concentration distribution of impurities.

[0075] Figure 1 is a graph showing the Li concentration among the component analysis results of Examples 1-5 and Comparative Examples 1-5, to be compared according to pH change.

[0076] Figure 2 is a graph showing the concentrations of Si and Al among the component analysis results of Examples 1-5 and Comparative Examples 1-5, to be compared according to pH change.

[0077] Figure 3 is a graph showing the concentrations of Mg and Fe among the component analysis results of Examples 1-5 and Comparative Examples 1-5, to be compared according to pH change.

[0078] Figure 4 is a graph showing the concentrations of Ca, Ni, and Mn among the component analysis results of Examples 1-5 and Comparative Examples 1-5, to be compared according to pH change.

[0079] Figure 5 is a graph showing the sum of the concentrations of impurity components Si+Al+Mg+Fe+Ca+Fe+Ni+Mn and the Li / (Si+Al+Mg+Fe+Ca+Fe+Ni+Mn) mass ratio calculated in Table 4 as a function of pH change. Since the concentrations of impurity components were significantly reduced in the pH environment of Examples 1-5, the Li / (Si+Al+Mg+Fe+Ca+Fe+Ni+Mn) mass ratio, conversely, was significantly increased in Examples 1-5.

[0080] Figure 6 is a graph showing the Li leaching rate (wt%) calculated in Table 4 as a function of pH change.

[0081] Looking at the results in Tables 1 to 3 above, in Examples 1-5, 70 to 86 wt% lithium leaching was possible in neutral, weakly alkaline, and weakly acidic pH 4.1-8.1. Regarding impurity concentrations, Mg was lowest at pH 8.1 or higher, while Al and Si were lowest at neutral pH and increased significantly at pH 3.6 or lower. In Example 5 (pH 4.1, Li 86.1 wt%), the lithium leaching rate was about 12 wt% lower than in Comparative Example 5 (pH 0.7, Li 98 wt%), but the mass ratio of Li / (Si+Al+Mg+Fe+Ca+Fe+Ni+Mn) was 2.059 in Example 5 and 0.436 in Comparative Example 5, which was 4.7 times higher. In Comparative Example 2 (pH 3.6), it is 0.644, and in Comparative Examples 2-5, it is understood that sulfuric acid is not consumed to leach Li but is consumed to dissolve impurities.

[0082] From Table 4, Figures 5 and 6, it can be seen that the Li / (Si+Al+Mg+Fe+Ca+Fe+Ni+Mn) mass ratio value of Examples 1-5 is higher than that of Comparative Examples 1-5. From this, it can be confirmed that Examples 1-5 meet the pH conditions that can increase the Li leaching rate while efficiently reducing impurities overall.

[0083]

[0084] Although the present invention has been described above with reference to embodiments, the present invention is not limited by the embodiments disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

1. A step of crushing waste refractory plates; and The method comprises the step of mixing a sulfuric acid solution with the crushed waste refractory casing to leach lithium and obtain a sulfuric acid leachate; The step of obtaining the above sulfuric acid leachate involves leaching lithium at a pH of 4.0 to 12.

0. Method for recovering lithium from waste refractory plates.

2. In Paragraph 1, The concentration of the sulfuric acid solution is adjusted so that the pH is between 4.0 and 12.

0. Method for recovering lithium from waste refractory plates.

3. In Paragraph 2, The concentration of the above sulfuric acid solution is 0.6 wt% to 1.2 wt% Method for recovering lithium from waste refractory plates.

4. In Paragraph 3, Mixing the sulfuric acid solution with the crushed waste refractory in an amount such that the weight ratio of the waste refractory to the sulfuric acid solution is 1:2 to 12. Method for recovering lithium from waste refractory plates.

5. In Paragraph 1, The content of lithium leached in the above sulfuric acid leachate is 1.0 g / L to 3.0 g / L Method for recovering lithium from waste refractory plates.

6. In Paragraph 1, The above sulfuric acid leachate has a content of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn of 0.3 g / L to 1.0 g / L. Method for recovering lithium from waste refractory plates.

7. In Paragraph 1, The mass ratio of Li content to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn in the above sulfuric acid leachate is 2.000 to 2.550 Method for recovering lithium from waste refractory plates.

8. In Paragraph 1, The above sulfuric acid leachate having a Si content of 3.75 g / L or less Method for recovering lithium from waste refractory plates.

9. In Paragraph 1, The above sulfuric acid leachate having an Al content of 0.09 g / L or less Method for recovering lithium from waste refractory plates.

10. In Paragraph 1, The above sulfuric acid leachate has an Mg content of 0.3 g / L or less Method for recovering lithium from waste refractory plates.

11. In Paragraph 1, The above sulfuric acid leachate has a Ca content of 0.022 g / L or less Method for recovering lithium from waste refractory plates.

12. In Paragraph 1, The above sulfuric acid leachate having a Ni content of 0.015 g / L or less Method for recovering lithium from waste refractory plates.

13. Sulfuric acid leachate of waste refractory armor in which the mass ratio of the content of Li to the sum of the contents of Si, Al, Mg, Fe, Ca, Fe, Ni, and Mn is 2.000 to 2.

550.

14. In Paragraph 13, lithium content of 0.3 g / L to 1.0 g / L Sulfuric acid leachate of waste refractory armor.

15. In Paragraph 13, Obtained by leaching with sulfuric acid at pH 4.0 to 12.0 Sulfuric acid leachate of waste refractory armor.

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