KR102488009B1 - Method for selective recovering Lithium by pyro- and hydrometallurgical process from Li-Al-Si(LAS) containing material - Google Patents

Abstract

The present invention includes a raw material acquisition step of obtaining powder by crushing and pulverizing a raw material containing LAS (Li-Al-Si); Heat treatment step of phase change to increase the volume of the powder; A first leach step of preparing a first leach solution by adding a first leach solution to the heat-treated raw material; a solid-liquid separation step of preparing a residue and a second leaching solution by solid-liquid separation of the first leaching solution; adjusting the pH of the second leaching solution to prepare a third leaching solution from which at least a portion of zinc (Zn) and aluminum (Al) is removed; And a solvent extraction step of solvent-extracting lithium in the third leaching solution; it relates to a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry-wet fusion smelting process.

Description

Method for selective recovery of lithium by pyro- and hydrometallurgical process from Li-Al-Si(LAS) containing material}

The present invention relates to a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry-wet fusion smelting process.

Lithium is a rare metal that is attracting attention thanks to the development of advanced IT technology in the future. About 65% of lithium is used in lithium ion batteries, 18% in Li-Al-Si(LAS) glass & ceramic, 5% in lubricants and grease, 1% in air treatment, 3% in polymers and aluminum casting powder 3% is consumed.

Among the refined lithium compounds, Li ₂ CO ₃ and LiOH are mostly used for manufacturing cathode active materials for lithium ion batteries. In particular, demand for lithium for batteries, which was only 30% due to the increase in demand for electric vehicles that use lithium-ion batteries as an energy source, is expected to reach 83% by 2025.

Demand for lithium, which is a major raw material that contains more than 7% of the cathode material in lithium-ion batteries, is expected to increase steadily as demand for electric vehicle batteries increases.

However, in the world, more than 50% of lithium is deposited in salt lakes in three South American countries, Chile, Argentina and Bolivia, more than 33% in Australia as ore, and more than 10% in salt lake and ore in China, so there is a problem with regional ubiquity. Occurs.

To solve this ubiquity of stores, a recycling process for recovering lithium from lithium ion batteries has been developed, but the recycling rate of lithium in the world is only 1%.

Therefore, in order to solve the ubiquity of lithium resources and the lack of supply of lithium due to the increase in demand for electric vehicles, it is essential to secure a new lithium raw material and a selective recovery method for this.

Korean Registered Patent No. 10-1011260 (registered on January 20, 2011) Korean Patent Registration No. 10-1623930 (registered on May 18, 2016)

An object of the present invention has been made to solve the above problems, and an object of the present invention is to provide a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry-wet fusion smelting process.

The present invention includes a raw material acquisition step of obtaining powder by crushing and pulverizing a raw material containing LAS (Li-Al-Si); Heat treatment step of phase change to increase the volume of the powder;

A first leach step of preparing a first leach solution by adding a first leach solution to the heat-treated raw material; a solid-liquid separation step of preparing a residue and a second leaching solution by solid-liquid separation of the first leaching solution; adjusting the pH of the second leaching solution to prepare a third leaching solution from which at least a portion of zinc (Zn) and aluminum (Al) is removed; And a solvent extraction step of solvent-extracting lithium in the third leaching solution; it relates to a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry-wet fusion smelting process.

The LAS (Li-Al-Si)-containing raw material may include at least one of induction, fireproof glass, a vision pot, and a hot plate.

The powder contains 1.2 to 1.7 wt% of lithium (Li), 0.2 to 0.5 wt% of magnesium (Mg), 1 to 1.5 wt% of zinc (Zn), 0.1 to 0.5 wt% of iron (Fe), and 8 to 15 wt% of aluminum (Al). It may include 1 to 1.5 wt% of titanium (Ti), 1 to 1.5 wt% of zirconium (Zr), and 25 to 35 wt% of silicon (Si).

The heat treatment in the heat treatment step may increase the volume of the powder by 2 to 6 times.

The heat treatment step may be performed at a temperature of 950 °C to 1050 °C for 2 h to 5 h.

The heat treatment may change the crystal structure of the powder from a hexagonal structure to a tetragonal structure.

The first leachate may include sodium hydroxide (NaOH).

The powder having a size of 50 mesh to 350 mesh is supplied to the first leaching step, and the first leaching step may be performed at a temperature of 20 ° C to 110 ° C and at 150 rpm to 300 rpm.

The solid-liquid separation step is performed using a filter, and the second leaching solution may include lithium (Li), zinc (Zn), aluminum (Al), sodium (Na), and silicon (Si).

The residue may include at least one of zeolite P1, zeolite LTA, and sodalite.

In the pH adjusting step, the pH of the second leaching solution may be adjusted to 3 to 9.

In the solvent extraction step, an extraction solvent may be added to the third leaching solution to obtain a lithium (Li) extraction solution from which at least a portion of sodium (Na) and silicon (Si) is removed.

The extraction solvent is (2-ethylhexyl)phosphonic acid Mono-2-ethylhexyl Ester (PC88A), di-(2-ethylhexyl)phosphoric acid (D2EHPA), bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), neodecanoic acid (Versatic 10 acid), tributyl phosphate (TBP), and trialkylphosphine oxide (Cyanex923).

After the solvent extraction step, a stripping step of recovering lithium as a lithium solution by stripping the lithium (Li) extraction solution may be further included.

In the stripping, at least one of hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), boric acid (H ₃ BO ₃ ), carbonic acid (H ₂ CO ₃ ) and nitric acid (HNO ₃ ) can be used.

According to the present invention, there is provided a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry/wet fusion smelting process.

1 is a process chart for a method for selectively recovering lithium by a dry/wet fusion smelting process from a raw material containing LAS (Li-Al-Si) according to an embodiment of the present invention;
Figure 2 shows the XRD analysis results and SEM of the LAS (Li-Al-Si) containing raw material according to the experimental example,
Figure 3 shows the XRD peak results after heat treatment according to the temperature according to the experimental example,
Figure 4 shows the XRD peak results after heat treatment over time at 1000 ° C conditions according to the experimental example,
Figure 5 shows the XRD analysis results of the residue obtained after leaching by temperature according to the experimental example,
Figure 6 shows the SEM results of the residue obtained after leaching by temperature according to the experimental example,
Figure 7 shows the XRD analysis results obtained after leaching according to the concentration of the first leachate treatment according to Experimental Example,
Figure 8 shows the SEM results of the residue obtained after leaching according to the concentration of the first leachate treatment according to Experimental Example,
9 shows the extraction behavior of lithium according to countercurrent multi-stage extraction experiment 1 according to the degree of saponification and the number of extraction stages;
10 shows the extraction behavior of lithium according to countercurrent multi-stage extraction experiment 2 according to the degree of saponification and the number of extraction stages;
11 shows the extraction behavior of lithium according to countercurrent multi-stage extraction experiment 3 according to the degree of saponification and the number of extraction stages;
12 shows the extraction behavior of lithium according to countercurrent multi-stage extraction experiment 4 according to the degree of saponification and the number of extraction stages;
13 shows the extraction behavior of lithium according to countercurrent multi-stage extraction experiment 5 according to the degree of saponification and the number of extraction stages;
14 shows the extraction behavior of lithium according to countercurrent multi-stage extraction experiment 6 according to the degree of saponification and the number of extraction stages;
15 shows the extraction behavior of lithium according to the countercurrent multi-stage extraction experiment 7 according to the degree of saponification and the number of extraction stages.

The present invention will be described in more detail with reference to the following drawings.

Since the accompanying drawings are only examples shown to explain the technical spirit of the present invention in more detail, the spirit of the present invention is not limited to the accompanying drawings. In addition, in the accompanying drawings, sizes and intervals may be exaggerated unlike actual ones in order to explain the relationship between each component.

Referring to FIG. 1, a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry/wet fusion smelting process according to the present invention will be described.

1 is a process chart for a method for selectively recovering lithium from a raw material containing LAS (Li-Al-Si) by a dry/wet fusion smelting process according to an embodiment of the present invention.

First, LAS (Li-Al-Si)-containing raw materials are crushed and pulverized to obtain powder. (Raw material acquisition step) (S1)

Here, the LAS (Li-Al-Si)-containing raw material may include at least one of induction, fireproof glass, vision pot, and hot plate, and may be mixed and used.

The powder, but is not limited thereto, may be obtained in the form of 6mesh size to 325mesh size powder through crushing and grinding of LAS (Li-Al-Si)-containing raw materials through a ball mill or planetary mill.

% in the present invention represents weight % unless otherwise specified.

Lithium (Li) in LAS (Li-Al-Si) may include 0.5-5%, 0.7-2.5%, or 1.1-1.9%.

Magnesium (Mg) may include 0.05-2.5%, 0.1-2.1%, or 0.15-0.9%.

Zinc (Zn) may include 0.5-5%, 0.7-2.5% or 1.1-1.8%.

Iron (Fe) may include 0.05-3.5%, 0.1-2.5% or 0.15-1.5%.

Aluminum (Al) may include 3-25%, 5-20% or 7-18%.

Titanium (Ti) may include 0.3-5%, 0.5-3% or 0.7-2.5%.

Zirconium (Zr) may include 0.5-5%, 0.7-2.5% or 0.8-2%.

Silicon (Si) sms may include 10-40%, 15-35% or 20-30%.

Specifically, LAS (Li-Al-Si) valuable metal composition is lithium (Li) 1.2-1.7%, magnesium (Mg) 0.2-0.5%, zinc (Zn) 1-1.5%, iron (Fe) 0.1-0.5%, It may be composed of 8-15% aluminum (Al), 1-1.5% titanium (Ti), 1-1.5% zirconium (Zr), and 25-35% silicon (Si).

Next, the obtained powder is subjected to heat treatment to undergo phase change to increase the volume of the powder. (Heat treatment step) (S2)

Heat treatment can increase the volume of the powder by a factor of 2 to 6.

The heat treatment step may be performed at a temperature of 950 °C to 1050 °C for 2 h to 5 h.

Heat treatment changes the crystal structure of the powder from hexagonal to tetragonal.

Next, a first leaching solution is prepared by adding a first leaching solution to the heat-treated raw material. (First leaching step) (S3)

In this step, the first leaching solution contains sodium hydroxide (NaOH), and sodium hydroxide (NaOH) leaches lithium from the heat-treated raw material through alkali leaching.

In the first leaching step, powder having a size of 50 mesh to 350 mesh may be supplied, and this step is performed at a temperature of 20° C. to 110° C. and at 150 rpm to 300 rpm.

Next, the first leaching solution is separated into solid and liquid to prepare a residue and a second leaching solution. (solid-liquid separation step) (S4)

The solid-liquid separation step is performed using a filter, and the second leaching solution may include lithium (Li), zinc (Zn), aluminum (Al), sodium (Na), and silicon (Si).

The residue may include at least one of zeolite P1, zeolite LTA, and sodalite, but is not limited thereto, and sodalite may be used as a heavy metal or valuable metal adsorbent through modification. .

Next, a third leaching solution in which at least a portion of zinc (Zn) and aluminum (Al) is removed is prepared by adjusting the pH of the second leaching solution. (pH adjustment step) (S5)

In this step, the pH of the second leaching solution may be adjusted to 1 to 10, 2 to 9, 3 to 8, or 4 to 7, but is not limited thereto, and the pH adjustment was performed using sulfuric acid (H ₂ SO ₄ ) .

Next, lithium in the third leaching solution is subjected to solvent extraction. (Solvent extraction step) (S6)

In the solvent extraction step, an extraction solvent is added to the third leaching solution to obtain a lithium (Li) extraction solution from which at least some of sodium (Na) and silicon (Si) are removed.

The extraction solvent is (2-ethylhexyl)phosphonic acid Mono-2-ethylhexyl Ester (PC88A), di-(2-ethylhexyl)phosphoric acid (D2EHPA), bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272 ), Neodecanoic acid (Versatic 10 acid), tributyl phosphate (TBP), and trialkylphosphine oxide (Cyanex923).

In this step, the O/A ratio is adjusted to 3 and 4 for countercurrent multistage extraction according to the degree of saponification and the number of extraction stages, and the degree of saponification is adjusted not to exceed a maximum of 15%. performed.

Next, after the solvent extraction step, the lithium aqueous solution obtained through solvent extraction is removed to recover lithium as a lithium solution. (Removal step) (S7)

The stripping solution for stripping the lithium aqueous solution is hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), boric acid (H ₃ BO ₃ ), carbonic acid (H ₂ CO ₃ ) and nitric acid (HNO ₃ ) may include at least one of them.

In this step, stripping was performed under conditions of O/A ratio of 1 to 20, 2 to 15, or 4 to 8 to show the removal rate of lithium according to the O/A ratio.

Hereinafter, the present invention will be described in more detail through experimental examples. However, the following experimental examples are intended to illustrate the present invention, and the scope of the present invention should not be construed as being limited to these experimental examples.

[Experiment 1: LAS( Li -Al- Si ) preparation of containing raw materials]

A study was conducted on powder obtained after crushing and grinding from raw materials such as induction, fireproof glass, vision pot, and hot plate, which are secondary resources containing (LAS) (Li-Al-Si). The LAS samples were crushed and pulverized through a ball mill or planetary mill, and the particle size was crushed and pulverized in various sizes ranging from 6 mesh to 325 mesh.

[Table 1]. LAS Valuable Metal Composition, wt.% Li Mg Zn Fe Al Ti Zr Si LAS 1.56 0.26 1.2 0.24 9.37 1.36 1.33 28.9

As shown in [Table 1], LAS is composed of 1.56% Li, 0.26% Mg, 1.2% Zn, 0.24% Fe, 9.37% Al, 1.36% Ti, 1.33% Zr, and 28.9% Si. The results of XRD analysis of this LAS are shown in FIG. 2 .

Looking at Figure 2, it can be seen that the LAS used in the experiment coincides with the peaks of Lithium Magnesium Zinc Aluminum Silicate and Zirconium Titanate.

After pulverization using a ball mill and planetary mill, particle size separation was performed for each mesh using a classifier.

Particle size separation was performed based on 6, 12, 18, 40, 60, 100, 270, and 325 mesh, and component analysis was conducted to find out the distribution of valuable metals for each particle size, and the composition of valuable metal elements for each particle size is shown in the table. 2.

[Table 2]. Composition of valuable metals by particle size after LAS grinding (oxide), wt.% mesh Li ₂ O ZnO MgO Fe ₂ O ₃ Al ₂ O ₃ TiO ₂ ZrO ₂ SiO ₂ 6 over 3.34 1.56 0.45 0.28 18.70 2.25 1.74 60.33 6-12 3.23 1.52 0.55 0.33 17.29 2.02 1.60 55.63 12-18 3.55 1.46 0.42 0.35 18.04 2.26 1.80 57.66 18-40 3.34 1.54 0.44 0.36 17.48 2.24 1.82 58.41 40-60 3.23 1.52 0.46 0.34 16.63 2.26 1.79 64.83 60-100 3.38 1.51 0.41 0.43 18.10 2.52 1.90 66.75 100-270 3.47 1.38 0.43 0.21 17.40 2.44 1.82 63.12 270-325 3.38 1.51 0.36 0.36 17.68 2.25 1.95 63.33 325 under 3.25 1.49 0.40 0.37 18.06 2.24 1.80 67.18

As shown in [Table 2], it can be seen that Li, Zn, Mg, Fe, Al, Ti, Zr, and Si in LAS are very similarly distributed in all particle sizes.

On average, Li ₂ O 3.35%, ZnO 1.5%, MgO 0.44%, Fe ₂ O ₃ 0.34% Al ₂ O ₃ 17.7%, TiO ₂ 2.27%, ZrO ₂ 1.8%, SiO ₂ 62%. This means that lithium cannot be physically concentrated.

Acid and alkali leaching was performed on the obtained sample to examine the leachability of lithium.

For acid leaching, 2M H ₂ SO ₄ and 2M HCl were used, and for alkali leaching, 5M NaOH was used.

The leaching experiment was performed for 3 hours under the conditions of a solid-liquid ratio of 1/10 (20g/200mL), 270 mesh undersize LAS, reaction temperature of 80°C, and stirring speed of 250rpm. The results are shown in [Table 3] below.

[Table 3]. Composition of acid/alkali leachate and residue of LAS sample before heat treatment, mg/L (solid-liquid ratio 1/10, 270mesh undersize LAS, reaction temperature 80℃, stirring speed 250rpm) Li Zn Fe Al pH mass, g 5M NaOH 330 218 0 1377 13.128 - residue 1118.95 949.9 322.805 5023.2 - 16.1 Total 1448.95 1167.9 322.81 6400.2 - - Leach rate, % 22.78 18.67 0.00 21.51 - - 2 M H ₂ SO ₄ 38 14.9 342 117.2 -0.312 - residue 1445.3 1251.3 9.894 5267.1 19.4 Total 1483.3 1266.2 351.894 5384.3 - Leach rate, % 2.56 1.18 97.19 2.18 - 2M HCl 42 16.3 356 109.5 -0.329 - residue 1351 1177.3 10.422 4255.65 19.3 Total 1393 1193.6 366.422 4365.15 - Leach rate, % 3.02 1.37 97.16 2.51 -

As can be seen in [Table 3], it can be seen that the leaching rates of lithium by sulfuric acid (H ₂ SO ₄ ) and hydrochloric acid (HCl) are quite low at about 2.56% and 3.02%.

On the other hand, the leaching rate of lithium by NaOH was 22.8%, which was 7 times higher than acid leaching. That is, it shows that LAS can be leached by alkali rather than acid leaching.

[Experiment 2: LAS phase change according to heat treatment conditions]

LAS having a β-quartz structure can undergo a phase change to β-spodumene depending on the temperature and time parameters between 900 and 1000 °C. Therefore, the LAS samples were heat treated at 800-1000 °C for 12 hours.

Figure 3 shows the XRD peak results after heat treatment according to the temperature according to the experimental example as described above.

According to FIG. 3, when heat treatment was performed at 800 ° C and 900 ° C for 12 hours, it was not observed that the crystal structure of LAS changed, and when heat treatment was performed at 1000 ° C for 12 hours, Li ₂ O Al ₂ having a tetragonal structure in a hexagonal structure. It was found that the phase was changed to O ₃ ·7.5SiO ₂ .

The phase change before and after heat treatment from the hexagonal structure to the tetragonal structure was judged to increase the leaching rate due to the 4-fold increase in the volume of LAS.

LAS heat treatment experiments according to time were performed by heat treatment at 1000 ° C for 30 minutes, 1 hour, 3 hours, 6 hours and 12 hours. The results are shown in FIG. 4 .

According to FIG. 4, in the sample heat-treated at 1000 ° C for 30 minutes and 1 hour, the LAS peak before heat treatment (Li, Mg, Zn) _1.7 Al ₂ O ₄ Si ₆ O ₁₂ and the LAS peak after heat treatment Li ₂ O ·Al ₂ O ₃ ·7.5SiO ₂ peaks were analyzed together.

When LAS was heat treated at 1000 ° C for 3, 6 and 12 hours, the (Li, Mg, Zn) _1.7 Al ₂ O ₄ Si ₆ O ₁₂ peak, which is the LAS peak before heat treatment, was not observed. Only Li ₂ O·Al ₂ O ₃ ·7.5SiO ₂ was analysed.

[Experiment 3: Leaching according to NaOH concentration using LAS after heat treatment]

An experiment was conducted to determine the effect of the concentration of NaOH aqueous solution on the leaching of lithium contained in LAS after heat treatment.

The concentration of NaOH was carried out in the range of 1, 2, 3, 4 and 5 M, and leaching was performed for 6 hours under the conditions of 270 mesh undersize, solid-liquid ratio 1/10, reaction temperature 100 ° C, stirring speed 250 rpm.

As shown in [Table 4] below, when 1M NaOH was used, the leaching rate of Li and Si increased over time, and the leaching rate of Zn content did not increase anymore and was analyzed similarly.

[Table 4]. Leaching rate by 1M NaOH from heat-treated LAS, % (1M NaOH, 270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 9.9 8.3 0.0 0.0 5.8 0.0 0.0 8.5 12.6 60 10.8 8.3 0.0 0.0 4.9 0.0 0.0 8.8 12.4 90 12.0 8.4 0.0 0.0 4.4 0.0 0.0 9.2 12.8 120 12.8 8.5 0.0 0.0 4.0 0.0 0.0 9.4 12.5 180 14.1 9.3 0.0 0.0 3.0 0.0 0.0 10.0 12.6 240 15.0 10.2 0.0 0.0 2.7 0.0 0.0 11.3 12.3 300 19.0 9.7 0.0 0.0 2.6 0.0 0.0 13.8 12.4 360 24.9 10.6 0.0 0.0 2.5 0.0 0.0 17.8 12.5

In the case of Al, it was observed that the leaching rate decreased over time, and Mg, Fe, Ti, and Zr were not analyzed.

Finally, when 6 hours had elapsed, the leachate contained 380 mg/L Li, 25 mg/L Zn, 218 mg/L Al, and 4.27 g/L Si, and the pH was 12.5.

Finally, when 6 hours elapsed, the Li leaching rate rose to about 25%, Zn 10.6%, Al 2.5%, and Si 17.8% were leached, and Mg, Fe, Ti and Zr leaching did not occur.

As shown in [Table 5], the leaching rate of Li and Si increased with time even in leaching using 2M NaOH, and the leaching rate of Al gradually decreased.

In the case of Zn, the leaching rate increased to 38% by 240 minutes and then decreased. Finally, when 360 minutes had elapsed, the leachate contained 1.23 g/L Li, 89 mg/L Zn, 86.2 mg/L Al, and 12.6 g/L Si, and the pH was 12.7.

[Table 5]. Leaching rate by 2M NaOH from heat-treated LAS, % (270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 14.7 19.0 0.0 0.0 9.1 0.0 0.0 14.2 12.5 60 17.4 23.9 0.0 0.0 8.0 0.0 0.0 16.2 12.4 90 20.8 27.0 0.0 0.0 7.0 0.0 0.0 18.6 12.3 120 26.2 30.5 0.0 0.0 6.0 0.0 0.0 21.2 12.5 180 36.2 36.4 0.0 0.0 4.9 0.0 0.0 28.2 12.6 240 51.0 38.4 0.0 0.0 3.7 0.0 0.0 36.1 12.8 300 67.1 30.1 0.0 0.0 2.2 0.0 0.0 41.9 12.5 360 82.5 30.8 0.0 0.0 1.0 0.0 0.0 49.2 12.7

As shown in [Table 5], the leaching rate of lithium increased with time and reached 82.5% after 360 minutes. Zn 30.8%, Al 1%, Si 49.2% were leached, Mg, Fe, Ti and no leaching of Zr occurred.

As shown in [Table 6] below, the leaching rates of Li and Si in the leaching solution using 3M NaOH increased with time, and it was found that the leaching rates decreased after 300 minutes for Zn and 30 minutes for Al. can

Finally, when 360 minutes had elapsed, the leachate contained 1.29 g/L Li, 134 mg/L Zn, 327 mg/L Al, and 14.1 g/L Si, and the pH was 13.5.

[Table 6]. Leaching rate by 3M NaOH from heat-treated LAS, % (270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 17.7 16.2 0.0 0.0 31.0 0.0 0.0 17.7 13.1 60 25.8 20.4 0.0 0.0 28.8 0.0 0.0 20.4 13.5 90 33.6 22.8 0.0 0.0 20.2 0.0 0.0 29.4 12.8 120 44.2 26.9 0.0 0.0 17.7 0.0 0.0 36.9 12.4 180 53.7 30.7 0.0 0.0 16.6 0.0 0.0 42.2 13.5 240 73.4 34.2 0.0 0.0 11.0 0.0 0.0 44.2 13.2 300 84.3 34.4 0.0 0.0 9.3 0.0 0.0 52.8 13.6 360 87.7 26.5 0.0 0.0 5.5 0.0 0.0 55.1 13.5

As can be seen in [Table 6], it can be seen that the leaching rates of Li and Si increased with time, and there was a section where the leaching rates of Zn and Al decreased.

After 6 hours, the leaching rates of valuable metals were 87.7%, 26.5%, 5.5%, and 55.1%, respectively, of Li, Zn, Al, and Si, and leaching of Mg, Fe, Ti, and Zr did not occur.

As shown in [Table 7], when the heat-treated LAS was leached using 4M NaOH, the contents of Li and Si increased over time, and in the case of Zn, the content was increased after 300 minutes and in the case of Al, after 30 minutes. You can see this decrease.

Finally, when leaching lasted for 360 minutes, 1.57 g/L Li, 167 mg/L Zn, 420 mg/L Al, and 20.2 g/L Si were contained, and the pH was 13.6.

[Table 7]. Leaching rate by 4M NaOH from heat-treated LAS, % (270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 21.2 22.6 0.0 0.0 40.3 0.0 0.0 20.7 13.1 60 29.1 28.0 0.0 0.0 37.9 0.0 0.0 24.2 13.8 90 46.0 31.3 0.0 0.0 31.7 0.0 0.0 34.0 13.5 120 49.6 35.2 0.0 0.0 28.7 0.0 0.0 40.3 12.9 180 63.6 38.7 0.0 0.0 24.7 0.0 0.0 48.6 13.1 240 81.7 40.9 0.0 0.0 11.4 0.0 0.0 59.6 13.2 300 87.2 40.5 0.0 0.0 10.4 0.0 0.0 63.3 13.5 360 95.0 34.3 0.0 0.0 6.9 0.0 0.0 67.3 13.6

As shown in [Table 7], even in leaching using 4M NaOH, the leaching rates of Li and Si increased with time, and it was found that there was a section in which the leaching rates of Zn and Al decreased.

After 6 hours, the leaching rates of Li, Zn, Al, and Si were 95%, 34.3%, 6.9%, and 67.3%, respectively, and Mg, Fe, Ti, and Zr were not leached.

As shown in [Table 8], the contents of Li and Si in the leachate using 5M NaOH increased over time, and it was found that the contents decreased after 300 minutes in the case of Zn and 30 minutes in the case of Al.

[Table 8]. Heat-treated LAS leaching rate, % (5M NaOH, 270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 29.5 11.4 0.0 0.0 26.1 0.0 0.0 33.1 13.8 60 44.3 16.7 0.0 0.0 25.9 0.0 0.0 37.0 13.5 90 61.8 17.6 0.0 0.0 12.2 0.0 0.0 39.1 13.6 120 80.0 24.5 0.0 0.0 2.4 0.0 0.0 44.3 13.5 180 96.2 31.7 0.0 0.0 1.1 0.0 0.0 51.6 13.6 240 98.8 27.9 0.0 0.0 0.8 0.0 0.0 58.9 13.4 300 99.5 39.3 0.0 0.0 0.2 0.0 0.0 60.4 13.8 360 97.5 30.5 0.0 0.0 0.4 0.0 0.0 68.3 13.6

Finally, when 360 minutes had elapsed, the leachate contained 1.5 g/L Li, 128 mg/L Zn, 19.6 mg/L Al, and g/L Si, and the pH was 13.6. It can be seen that the leaching rates of Li and Si increased over time, and there was a section where the leaching rates of Zn and Al decreased.

After 5 hours, the leaching rate of valuable metals was 99.5% Li, 39.3% Zn, 0.2% Al, and 60.4% Si, and finally, after 6 hours, the leaching rates of valuable metals were 97.5% each of Li, Zn, Al, and Si; 30.5%, 0.4%, and 68.3% of Mg, Fe, Ti and Zr were not leached. That is, when 5M NaOH was used, more than 99.5% of lithium was leached after 5 hours.

[Experiment 4: Leaching of lithium (Li) according to the particle size of LAS after heat treatment]

An experiment was conducted to investigate the effect of the particle size of the sample on the leaching of lithium in LAS after heat treatment.

The particle size was performed in the range of 100mesh oversize, 100-270mesh, 270-325mesh, and 325mesh undersize, and leached for 6 hours under the conditions of 5M NaOH, solid-liquid ratio 1/10, reaction temperature 100 ℃, stirring speed 250rpm.

[Table 9] shows the leaching rate of valuable metals over time when LAS of 100 mesh oversize was leached using 5M NaOH.

[Table 9]. Leaching rate of LAS 100mesh oversize heat treated at 1000℃ for 3 hours, % (5M NaOH, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 6.7 7.3 0.0 0.0 17.6 0.0 0.0 9.4 13.6 60 11.1 8.8 0.0 0.0 19.9 0.0 0.0 11.8 13.8 90 17.1 13.2 0.0 0.0 22.8 0.0 0.0 13.6 13.4 120 23.0 16.6 0.0 0.0 30.8 0.0 0.0 18.3 12.8 180 29.4 24.6 0.0 0.0 20.9 0.0 0.0 20.6 13.1 240 32.2 29.7 0.0 0.0 19.7 0.0 0.0 27.9 13.6 300 44.8 34.8 0.0 0.0 12.9 0.0 0.0 31.4 13.4 360 49.4 45.4 0.0 0.0 8.5 0.0 0.0 33.7 13.3

Looking at [Table 9], it can be seen that the leaching rates of Li, Zn, and Si increased with time, and in the case of Al, the leaching rates decreased after 120 minutes.

After 6 hours of leaching, 750 mg/L Li, 150 mg/L Zn, 411.2 mg/L Al, and 10.2 g/L Si were contained in the leaching solution.

The residue generated after leaching was 15.2 g. When the leaching was 6 hours, the leaching rates of Li, Zn, Al and Si were 49.4%, 45.4%, 8.5% and 33.7%, respectively.

[Table 10] below shows the leaching rate of valuable metals over time when 100-270 mesh heat-treated LAS was leached using 5M NaOH.

The leaching rates of Li, Zn, and Si increased with time, and in the case of Al, the leaching rates decreased after 60 minutes.

[Table 10]. Leaching rate of LAS 100-270mesh heat treated at 1000℃ for 3 hours, % (5M NaOH, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 11.3 10.1 0.0 0.0 18.8 0.0 0.0 13.4 13.5 60 15.5 19.9 0.0 0.0 27.5 0.0 0.0 18.0 13.4 90 18.7 24.8 0.0 0.0 19.7 0.0 0.0 19.9 13.1 120 22.5 29.4 0.0 0.0 17.9 0.0 0.0 22.2 12.9 180 30.9 35.2 0.0 0.0 12.2 0.0 0.0 25.2 13.2 240 42.5 39.5 0.0 0.0 5.9 0.0 0.0 32.0 13.5 300 52.2 47.5 0.0 0.0 4.5 0.0 0.0 41.0 13.6 360 68.3 54.8 0.0 0.0 3.7 0.0 0.0 51.0 13.8

After 6 hours of leaching, 1.06 g/L Li, 147.7 mg/L Zn, 196 mg/L Al, and 15.2 g/L Si were contained in the leaching liquid, and 12.5 g of residue was generated after leaching. When leaching was 6 hours, the leaching rates of Li, Zn, Al and Si were 68.3%, 54.8%, 3.7% and 51%, respectively.

Table 11 below shows the leaching rate of valuable metals over time when 270-325 mesh heat-treated LAS was leached using 5M NaOH.

[Table 11]. Leaching rate of LAS 270-325 mesh heat-treated at 1000℃ for 3 hours, % (5M NaOH, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 36.9 41.1 0.0 0.0 37.3 0.0 0.0 34.9 13.9 60 43.7 55.2 0.0 0.0 34.0 0.0 0.0 40.5 13.4 90 56.6 58.8 0.0 0.0 19.9 0.0 0.0 47.5 13.5 120 70.7 60.3 0.0 0.0 10.8 0.0 0.0 61.1 13.6 180 83.7 54.6 0.0 0.0 7.3 0.0 0.0 65.7 13.4 240 91.0 41.4 0.0 0.0 5.0 0.0 0.0 68.1 13.2 300 99.7 33.0 0.0 0.0 3.5 0.0 0.0 67.7 13.6 360 92.9 31.8 0.0 0.0 0.3 0.0 0.0 68.1 13.8

The leaching rate of Li and Si increased with time, and the leaching rate of Zn began to decrease after 120 minutes, and in the case of Al, the leaching rate decreased after 30 minutes. The leaching rate of lithium was the highest at 99.7% after 5 hours.

[Table 12] below shows the leaching rate of valuable metals over time when heat-treated LAS of 325 mesh undersize was leached using 5M NaOH.

[Table 12]. Leaching rate, % of LAS 325mesh undersize heat-treated at 1000℃ for 3 hours (5M NaOH, solid-liquid ratio 1/10, stirring speed 250rpm, reaction temperature 100℃) min Li Zn Mg Fe Al Ti Zr Si pH 30 37.5 46.0 0.0 0.0 39.5 0.0 0.0 35.2 13.4 60 43.8 61.0 0.0 0.0 33.1 0.0 0.0 39.7 13.5 90 59.1 67.4 0.0 0.0 21.5 0.0 0.0 47.0 13.9 120 77.5 62.7 0.0 0.0 12.9 0.0 0.0 62.4 13.5 180 87.0 46.0 0.0 0.0 7.4 0.0 0.0 64.1 13.4 240 92.8 41.9 0.0 0.0 3.9 0.0 0.0 68.3 13.6 300 99.1 36.8 0.0 0.0 2.3 0.0 0.0 68.7 13.2 360 90.2 33.7 0.0 0.0 0.2 0.0 0.0 69.3 13.5

Looking at [Table 12], similar to the 270-325 mesh LAS leaching results in Table 11, the leaching rates of Li and Si increased with time, and the leaching rates of Zn decreased after 90 minutes.

In the case of Al, the leaching rate decreased after 30 minutes. The leaching rate of lithium was the highest at 99.1% after 5 hours.

[Experiment 5: Lithium leaching rate according to LAS reaction temperature after heat treatment]

Heat-treated LAS leaching experiments according to the reaction temperature were carried out in the range of 40, 60, 80 and 100 ℃ under the conditions of 5M NaOH, 270 mesh undersize, solid-liquid ratio 1/10, stirring speed 250 rpm.

[Table 13] shows the leaching rate over time of valuable metals leached under the condition of 40°C. The leachate after 30 minutes of leaching contained 25 mg/L Li, 5.8 mg/L Zn, 93.1 mg/L Al, and 322.1 mg/L Si, and the content of each valuable metal increased as time passed.

[Table 13]. Heat-treated LAS, leaching rate of valuable metals when leaching at 40℃, % (5M NaOH, 270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm) min Li Zn Mg Fe Al Ti Zr Si pH 30 1.6 1.5 0.0 0.0 1.8 0.0 0.0 1.4 13.50 60 2.1 2.0 0.0 0.0 2.6 0.0 0.0 1.9 13.21 90 2.7 2.5 0.0 0.0 3.5 0.0 0.0 2.6 13.63 120 3.0 2.7 0.0 0.0 3.9 0.0 0.0 3.2 13.51 180 3.7 3.2 0.0 0.0 4.8 0.0 0.0 4.0 13.42 240 4.2 3.4 0.0 0.0 5.6 0.0 0.0 5.3 13.21 300 4.7 3.7 0.0 0.0 6.0 0.0 0.0 6.5 13.15 360 4.9 3.8 0.0 0.0 6.8 0.0 0.0 7.0 13.16

As can be seen in [Table 13], when the final 360 minutes elapsed, the valuable metals were leached with 4.9% Li, 3.8% Zn, 6.8% Al, and 7% Si. And leaching of Mg, Fe, Ti and Zr did not occur.

[Table 14] shows the leaching rate over time of valuable metals leached under the condition of 60°C.

[Table 14]. Heat-treated LAS, leaching rate of valuable metals when leaching at 60℃, % (5M NaOH, 270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm) min Li Zn Mg Fe Al Ti Zr Si pH 30 4.0 3.2 0.0 0.0 3.4 0.0 0.0 5.1 12.78 60 5.7 3.6 0.0 0.0 5.1 0.0 0.0 7.1 13.15 90 7.5 5.6 0.0 0.0 7.8 0.0 0.0 10.6 13.25 120 8.8 7.1 0.0 0.0 9.0 0.0 0.0 11.5 13.64 180 10.3 10.5 0.0 0.0 11.1 0.0 0.0 13.9 13.51 240 12.0 13.1 0.0 0.0 13.8 0.0 0.0 16.9 12.89 300 14.8 15.1 0.0 0.0 15.4 0.0 0.0 19.4 13.15 360 16.1 16.5 0.0 0.0 17.4 0.0 0.0 21.8 13.64

Looking at [Table 14], the leachate after 30 minutes contained 62 mg/L Li, 13.3 mg/L Zn, 269 mg/L Al, and 1.3 g/L Si, and the content gradually increased as time passed. .

After the final 360 minutes, the leaching rates of each valuable metal were 16.1% Li, 16.5% Zn, 17.4% Al, and 21.8% Si, and no leaching of Mg, Fe, Ti, and Zr occurred.

[Table 15] below shows the leaching rate over time of valuable metals leached under the condition of 80 ° C.

[Table 15]. Heat-treated LAS, leaching rate of valuable metals when leaching at 80℃, % (5M NaOH, 270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm) min Li Zn Mg Fe Al Ti Zr Si pH 30 13.4 13.4 0.0 0.0 14.0 0.0 0.0 15.0 13.02 60 16.7 20.0 0.0 0.0 20.3 0.0 0.0 20.7 13.32 90 23.8 25.4 0.0 0.0 26.0 0.0 0.0 26.8 13.51 120 28.9 28.7 0.0 0.0 30.1 0.0 0.0 31.0 12.98 180 34.7 32.3 0.0 0.0 33.4 0.0 0.0 36.2 13.42 240 42.4 34.4 0.0 0.0 25.2 0.0 0.0 39.7 13.24 300 50.1 36.9 0.0 0.0 12.7 0.0 0.0 39.7 13.33 360 69.3 40.5 0.0 0.0 4.1 0.0 0.0 51.4 13.27

The leachate after 30 minutes contained 209 mg/L Li, 49 mg/L Zn, 685 mg/L Al, and 4.4 g/L Si, and as time passed, the contents of Li, Zn, and Si, excluding Al, increased. When 360 minutes had elapsed, 1.08 g/L Li, 148 mg/L Zn, 198 mg/L Al, and 15 g/L Si were contained.

As can be seen from [Table 15], when leaching was 30 minutes, Li 13.4%, Zn 13.4%, Al 14%, and Si 15% were leached, and finally, when 360 minutes had elapsed, Li 69.3%, Zn 40.5% , 4.1% of Al and 51.4% of Si were leached out.

[Table 16] below shows the leaching rate over time of valuable metals leached under the condition of 100°C.

When leached at 100 ° C, 610 mg / L Li, 142 mg / L Zn, 2.24 g / L Al, and 10.5 g / L Si were contained in the leaching solution after 30 minutes. In the case of Li and Si, the content increased over time, and in the case of Al, the content continued to decrease.

[Table 16]. Heat-treated LAS, leaching rate of valuable metals when leached at 100℃, % (5M NaOH, 270mesh undersize, solid-liquid ratio 1/10, stirring speed 250rpm) min Li Zn Mg Fe Al Ti Zr Si pH 30 38.4 53.5 0.0 0.0 44.8 0.0 0.0 35.4 12.85 60 51.7 67.8 0.0 0.0 37.2 0.0 0.0 42.2 13.21 90 69.3 71.9 0.0 0.0 25.0 0.0 0.0 52.7 13.41 120 81.3 73.4 0.0 0.0 11.6 0.0 0.0 54.0 12.89 180 86.9 71.5 0.0 0.0 8.4 0.0 0.0 59.1 13.32 240 92.0 65.5 0.0 0.0 6.1 0.0 0.0 62.8 13.25 300 99.5 57.2 0.0 0.0 4.8 0.0 0.0 65.5 13.61 360 91.3 48.2 0.0 0.0 0.4 0.0 0.0 65.5 13.22

As shown in [Table 16], after 5 hours, 99.5% Li, 57.4% Zn, 4.8% Al, and 65.5% Si were leached, resulting in maximum lithium leaching.

[Experiment 6: Generation of zeolite in the residue generated after leaching from the heat-treated LAS sample]

The residue obtained after leaching at 40-100 ° C was analyzed by XRD and SEM, and the results are shown in FIGS. 5 and 6 .

As can be seen in FIG. 5, it can be seen that the composition of the raw material in the residue does not change at all up to 60 ° C., and Li ₂ O·Al ₂ O ₃ ·7.5SiO ₂ and ZrTiO ₄ are observed.

However, Na ₁₂ Al ₁₂ Si ₁₂ O ₄₈ ·(H ₂ O) ₂₇ (Zeolite LTA), a type of zeolite, was observed after 80 °C. And it was confirmed that the residue obtained after leaching at 100°C was Na ₈ (Al ₆ Si ₆ O ₂₄ )(OH) ₂ ·(H ₂ O) ₂ (Sodalite).

This means that the leaching temperature during alkaline leaching of heat-treated LAS has a significant effect on the structure of zeolite that can be produced from the leaching residue. That is, the type of zeolite produced in the residue differs depending on the leaching temperature. Zeolite LTA was formed at 80 ° C and Sodalite of Na ₈ (Al ₆ Si ₆ O ₂₄ ) (OH) ₂ (H ₂ O) ₂ was formed at 100 ° C. has been formed

7 and 8 show the XRD and SEM results of the residue obtained after LAS leaching according to the NaOH concentration under the condition of 100 ° C.

As shown in FIG. 7, as a result of XRD analysis of the leach residue according to the NaOH concentration, zeolite P1 (Na _{6 Al6} Si ₁₀ O ₁₂ (H ₂ O) ₁₂ ) was formed in the residue first in 2M NaOH, and zeolite in the residue when 4M NaOH was used LTA (Na ₁₂ Al ₁₂ Si ₁₂ O ₄₈ (H ₂ O) ₂₇ ) and sodalite (Na ₈ Al ₆ Si ₆ O ₂₃ (OH) ₂ (H ₂ O) ₂ ) were formed and sodalite ( Only Na ₈ Al ₆ Si ₆ O ₂₃ (OH) ₂ (H ₂ O) ₂ ) was formed.

This means that the formation of zeolite is significantly affected not only by temperature but also by the concentration of NaOH. At the same time, since the concentration of Na ⁺ ions participating in the formation of zeolite is different, the type of zeolite that can be formed is different depending on the NaOH concentration. .

This can be seen in the SEM analysis of FIG. 8 based on the XRD results of FIG. 7. The leaching residue of 1M NaOH is not significantly different from the heat-treated LAS, which is a leaching sample, and it can be seen that zeolite crystals are formed on the surface from 2M NaOH. .

It can be seen that zeolite LTA and sodalite are formed in the 4M NaOH leaching residue, and sodalite is densely formed in the leaching residue of 5M NaOH. The sodalite thus formed can be used as a heavy metal or valuable metal adsorbent through modification.

[Experiment 7: Lithium Recovery by Solvent Extraction]

[Table 17] below shows the composition of the leachate obtained after leaching the heat-treated LAS under the conditions of 5M NaOH, 53㎛ undersize, 20g/200mL, 100℃, 250rpm, and 5h.

[Table 17]. Composition of heat-treated LAS leachate, mg/L (leaching conditions: 5M NaOH, 53㎛ undersize, 20g/200mL, 100℃, 250rpm, 5h) Li Zn Mg Fe Al Ti Zr Si Na pH leachate 1440 154 - - 167 - - 18,300 90550 12.56 pH 11 1330 - - - - - - 3737 81860 11.01 pH 6.5 1307 - - - - - - 63.3 48110 6.56

As can be seen in [Table 17], 1.44 g/L Li, 154 mg/L Zn, 167 mg/L Al, 18.3 g/L Si, and 90.5 g/L Na were contained in the leachate of the heat-treated LAS, and the pH was 12.56. was

After heating the leachate to 60° C., the pH was adjusted to 11 and pH 6.5 by adding 5M H ₂ SO ₄ to precipitate Si in the form of SiO ₂ .

In the aqueous solution whose pH was adjusted to 6.5, 1.3 g/L Li, 63.3 mg/L Si, and 48.1 g/L Na were contained.

Accordingly, based on the composition of the leachate, 99.6% of Si and 46.9% of Na were precipitated and removed, and Zn and Al contained in small amounts could also be removed. And about 100 ppm of lithium was diluted by adding a pH adjuster.

Using this aqueous solution, the extraction behavior of Li, Na, and Si according to the equilibrium pH was examined using 1M D2EHPA, 1M PC88A, 1M Versatic 10 acid, and 1M Cyanex 272.

[Table 18] below shows the extraction rate of valuable metals according to the equilibrium pH under the condition of O/A=1 when 1M D2EHPA was used.

[Table 18]. When extracted using 1M D2EHPA, extraction rate according to equilibrium pH, % (O/A=1) equilibrium pH Li Na Si Feed(mg/L) 1307 48110 63.3 2.08 6.50 0.94 1.99 2.52 11.91 3.85 2.88 3.01 21.25 5.11 3.13 3.52 28.88 5.78 3.76 4 39.07 9.25 6.33 5 39.56 18.19 4.31 5.5 40.44 16.11 5.78

As shown in [Table 18], when 1M D2EHPA was used, the initial equilibrium pH was 2.08, and at this time, 1.22g/L Li, 47.6g/L Na, and 62mg/L Si were contained in the raffinate. . The extraction rate at this time corresponds to 6.5% Li, 0.94% Na, and 1.99% Si.

As the equilibrium pH increased, the extraction rate of Li, Na, and Si increased, and it can be seen that the extraction rate of lithium appeared similar to about 40% from pH 4 or higher.

[Table 19] shows the extraction rate of valuable metals according to the equilibrium pH under the condition of O/A = 1 using 1M PC88A.

[Table 19]. When extracted using 1M PC88A, extraction rate according to equilibrium pH, % (O/A=1) equilibrium pH Li Na Si Feed(mg/L) 1307 48110 63.3 2.36 2.39 1.14 0.63 3.09 7.28 1.37 2.69 3.5 8.19 2.10 2.21 4.02 21.25 3.35 4.11 4.5 25.49 6.26 3.16 5 38.42 9.54 4.90 5.51 43.93 13.26 4.58 6.01 44.35 13.51 8.69 6.5 45.59 19.83 11.37

As shown in [Table 19], when 1M PC88A was used, the initial equilibrium pH was 2.36, and at this time, 1.28 g/L Li, 47.6 g/L Na, and 62.9 mg/L Si were contained in the raffinate. .

Corresponding extraction rates correspond to 2.39% Li, 1.14% Na, and 0.63% Si. As the equilibrium pH increased, the extraction rate of Li, Na, and Si increased, and from pH 5.5 or higher, the extraction rate of lithium was about 44%, slightly higher than that of D2EHPA at the same concentration.

[Table 20] below shows the extraction rate of valuable metals according to the equilibrium pH at O/A = 1 when 1M Versatic 10 acid was used.

[Table 20]. When extracted using 1M Versatic 10 acid, extraction rate according to equilibrium pH, % (O/A=1) equilibrium pH Li Na Si Feed(mg/L) 1307 48110 63.3 2.57 2.62 4.09 0.79 3.12 3.18 3.91 1.11 3.63 4.12 5.28 3.00 4.41 4.50 6.80 3.48 5.06 5.10 7.88 3.79 5.54 5.74 7.50 4.42 6.21 6.34 4.74 6.48 6.51 6.65 4.76 8.21 7 9.32 4.36 9.64 7.52 10.63 6.36 9.79

Looking at [Table 20], when 1M Versatic 10 acid was used, the initial equilibrium pH was 2.57, and at this time, 1272.8g/L Li, 46.1g/L Na, and 62.8mg/L Si were contained in the raffinate. it had been

Corresponding extraction rates correspond to 2.62% Li, 4.09% Na, and 0.79% Si. In the case of Versatic 10 acid, the extraction rates of Li, Na, and Si did not increase significantly even when the equilibrium pH increased.

[Table 21] shows the extraction rate of valuable metals according to the equilibrium pH under the condition of O/A=1 when 1M Cyanex 272 was used.

[Table 21]. When extracted using 1M Cyanex 272, extraction rate according to equilibrium pH, % (O/A=1) equilibrium pH Li Na Si Feed(mg/L) 1307 48110 63.3 2.6 3.76 3.60 0.95 3.06 3.84 3.08 1.74 3.61 6.24 4.18 3.00 4.14 7.18 4.72 2.84 5.05 9.07 6.92 4.11 5.33 10.03 6.59 6.00 6.01 21.73 9.06 7.42 6.51 35.84 13.82 9.16 7 39.62 18.46 9.32

As shown in [Table 21], when solvent extraction was performed using 1M Cyanex 272, the initial equilibrium pH was 2.6, and Li, Na, and Si were 3.76%, 3.6%, and 0.95%, respectively. As the equilibrium pH increased, the extraction rate increased. can know that

When examining the pH-isotherm of 1M D2EHPA, PC88A, Versatic 10 acid and Cyanex 272, there was no solvent with a lithium extraction rate of more than 50%.

Among them, the highest lithium leaching rate was about 45% at an equilibrium pH of 5.5 when 1M PC88A was used.

Therefore, the extraction rate of lithium according to the concentration of PC88A was investigated by adjusting the equilibrium pH to 5.5 under the conditions of 0.2, 0.4, 0.6, 0.8 and 1M of PC88A.

[Table 22] below shows the extraction rate according to the concentration of PC88A.

[Table 22]. Extraction rate according to PC88A concentration, % (O/A=1, equilibrium pH 5.5) Li Na Si Feed(mg/L) 1270.7 45980 66.93 0.2M 6.4 1.7 7.7 0.4M 19.9 6.4 10.3 0.6M 33.2 20.5 11.5 0.8M 40.5 20.8 15.1 1M 46.3 21.2 17.8

As shown in [Table 22], the extraction rates of Li, Na, and Si in 1M PC88A were the highest at 46.3%, 21.2%, and 17.8%, respectively.

Therefore, countercurrent multi-stage extraction experiments were conducted according to the degree of saponification and the number of extraction stages using PC88A.

9 shows the extraction behavior of lithium in 1M PC88A, O/A = 3, 0% saponification, and 3 stages of extraction. Fig. As can be seen in Fig. 9, only about 9 mg/L of lithium was extracted. At this time, the pH was 2.32.

10 shows the extraction behavior of lithium in 1M PC88A, O/A = 3, 0% saponification, and 4 stages of extraction. As can be seen from FIG. 10, only about 11 mg/L of lithium was extracted. At this time, the pH was 2.35.

9 and 10, since the saponification was 0%, the equilibrium pH after extraction was low, and as a result, extraction of lithium was not performed. Therefore, countercurrent multi-stage extraction experiments were conducted with saponification degrees of 5, 10, and 15%.

11 shows the extraction behavior of lithium in 1M PC88A, O/A = 3, saponification 5%, and 4 stages of extraction. As can be seen from FIG. 11, about 176 mg/L of lithium was extracted into the organic phase. This is a value corresponding to the amount of 528 mg/L Li extracted when converted to an O/A ratio of 1 because the O/A ratio is 3. However, 751 mg/L Li was left unextracted in the raffinate.

12 shows the extraction behavior of lithium in 1M PC88A, O/A = 3, 10% saponification, and 4 stages of extraction. As can be seen in FIG. 12, about 371 mg/L of lithium was extracted into the organic phase. This is a value corresponding to the amount of 1113 mg/L Li extracted when converted to an O/A ratio of 1 because the O/A ratio is 3. However, 162 mg/L Li was left unextracted in the raffinate.

13 shows the extraction behavior of lithium in 1M PC88A, O/A = 4, 10% saponification, and 4 stages of extraction. As can be seen in FIG. 13, about 284.7 mg/L of lithium was extracted into the organic phase. This is a value corresponding to the amount of 1138.8 mg/L Li extracted when converted to an O/A ratio of 1 because the O/A ratio is 4. However, 111.2 mg/L Li was left unextracted in the raffinate.

14 shows the extraction behavior of lithium in 1M PC88A, O/A = 3, 15% saponification, and 4 stages of extraction. As shown in FIG. 14, about 400 mg/L of lithium was extracted into the organic phase. This is a value corresponding to the amount of 1200 mg/L Li extracted when converted to an O/A ratio of 1 because the O/A ratio is 3. However, 21.3 mg/L Li was left unextracted in the raffinate.

15 shows the extraction behavior of lithium in 1M PC88A, O/A = 4, 15% saponification, and 4 stages of extraction. As can be seen in FIG. 15, about 322 mg/L of lithium was extracted into the organic phase. This is a value corresponding to the amount of 1288 mg/L Li extracted when converted to an O/A ratio of 1 because the O/A ratio is 3. And 11.4 mg/L Li was left unextracted in the raffinate.

[Table 23] shows the countercurrent multi-stage extraction results according to the degree of saponification, the O/A ratio, and the number of extraction stages.

In the present invention, saponification is performed because hydrogen ions are generated when an acidic extractant is used to extract metal ions, but at this time, the pH is decreased and metal ions are not extracted. Below is a reaction formula for the saponification of the present invention.

[reaction formula]

(1) H ₂ A ₂ + M ²⁺ = MA ₂ + 2H ⁺

(2) Na ₂ A ₂ + M ²⁺ = MA ₂ + 2Na ⁺

In Reaction Formulas (1) and (2), H (hydrogen), A (extractant), M (metal), and Na (sodium) are shown.

As can be seen through the reaction formula, when saponification is performed to remove H ⁺ ions from the solvent and attach Na ⁺ ions, the pH does not decrease after extraction, so the extraction of metal ions proceeds in the forward direction.

[Table 23]. 1M PC88A Saponification degree, O/A ratio, counterflow multi-stage extraction result according to the number of extraction stages, % Experiment conditions Li Na Si pH Saponification 0%, O/A=3 2.1 0 0 2.32 Saponification 0%, O/A=4 2.6 0 0 2.35 Saponification 5%, O/A=3 41.2 -0.7 0 3.72 Saponification 10%, O/A=3 87.3 -One 0 4.43 Saponification 10%, O/A=4 91.1 -8.8 0 4.81 Saponification 15%, O/A=3 98.3 -10.8 0 4.99 Saponification 15%, O/A=4 99.1 -10 0 4.98

As can be seen in [Table 23], as the degree of saponification and the O/A ratio increased, the extraction rate of lithium increased while the extraction rate of Na decreased. In particular, the reason why the extraction rate of Na has a negative sign is that as the number of extraction stages increases, Na, which was saponified in the solvent, moves into the aqueous solution and lithium in the aqueous solution moves into the organic phase.

In conclusion, about 99.1% of lithium was extracted under the conditions of 1M PC88A, 15% saponification, and O/A = 4, and Na and Si were not extracted at all.

[Experiment 8: Removal of concentrated lithium]

Table 24 below shows the results of lithium stripping experiments when O/A ratios were 1, 2, 4, 6, 8, 10, 15, and 20 under conditions of 1M H ₂ SO ₄ and 25°C.

As shown in [Table 24], as a result of the lithium removal experiment according to the O/A ratio, the Li removal rate was 96% or more in all experimental conditions.

[Table 24]. Stripping test results according to O/A ratio Li removal rate, % Li content, mg/L pH O/A = 1 100 248.4 -0.05 O/A = 2 98.4 488.2 -0.03 O/A = 4 97.6 967.8 -0.04 O/A = 6 97 1443.2 -0.03 O/A = 8 96.8 1920 -0.01 O/A = 10 96.9 2402 0.00 O/A = 15 99.3 3812 0.62 O/A = 20 99.9 5114 1.37

[Table 24] shows the content of concentrated lithium according to the O/A ratio test results. About 248mg/L at O/A=1, 488mg/L at O/A=2, 967mg/L at O/A=4, 1443mg/L at O/A=6, 1920mg/L at O/A=8 , 2402 mg/L at O/A = 10, 3812 mg/L at O/A = 15, and finally 5114 mg/L at O/A = 20.

The above-described embodiments are examples for explaining the present invention, but the present invention is not limited thereto. Those skilled in the art to which the present invention pertains will be able to practice the present invention with various modifications therefrom, so the technical protection scope of the present invention should be defined by the appended claims.

Claims (15)

A raw material acquisition step of obtaining powder by crushing and pulverizing raw materials including lithium, aluminum, and silicon compounds;
Heat treatment step of phase change to increase the volume of the powder;
A first leach step of preparing a first leach solution by adding a first leach solution to the heat-treated raw material;
a solid-liquid separation step of preparing a residue and a second leaching solution by solid-liquid separation of the first leaching solution;
adjusting the pH of the second leaching solution to prepare a third leaching solution from which at least a portion of zinc (Zn) and aluminum (Al) is removed; and
A solvent extraction step of solvent-extracting lithium in the third leaching solution; includes,
In the solvent extraction step,
An extraction solvent is added to the third leaching solution to obtain a lithium (Li) extraction solution from which at least some of sodium (Na) and silicon (Si) are removed,
After the solvent extraction step, further comprising a stripping step of recovering lithium as a lithium solution by stripping the lithium (Li) extraction solution,
In the stripping, at least one of hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), boric acid (H ₃ BO ₃ ), carbonic acid (H ₂ CO ₃ ) and nitric acid (HNO ₃ ) Method for selectively recovering lithium by dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds using In paragraph 1,
The raw material containing the lithium, aluminum and silicon compounds,
A method for selectively recovering lithium by a dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds, comprising at least one of induction, fireproof glass, vision pot and hot plate. In paragraph 1,
The powder contains 1.2 to 1.7 wt% of lithium (Li), 0.2 to 0.5 wt% of magnesium (Mg), 1 to 1.5 wt% of zinc (Zn), 0.1 to 0.5 wt% of iron (Fe), and 8 to 15 wt% of aluminum (Al). From raw materials containing lithium, aluminum and silicon compounds, characterized in that they include 1 to 1.5% by weight of titanium (Ti), 1 to 1.5% by weight of zirconium (Zr), and 25 to 35% by weight of silicon (Si). A method for selective recovery of lithium by dry/moisture fusion smelting process. In paragraph 1,
A method for selectively recovering lithium by a dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds, characterized in that the volume of the powder is increased by 2 to 6 times by the heat treatment in the heat treatment step. In paragraph 4,
In the heat treatment step,
A method for selectively recovering lithium by a dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds, characterized in that carried out for 2h to 5h at a temperature of 950 ° C to 1050 ° C. In paragraph 5,
The heat treatment,
A method for selectively recovering lithium by a dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds, characterized in that the crystal structure of the powder is changed from a hexagonal structure to a tetragonal structure. In paragraph 1,
The first leachate is a method for selectively recovering lithium by a dry/wet fusion smelting process from a raw material containing lithium, aluminum and silicon compounds, characterized in that it contains sodium hydroxide (NaOH). In paragraph 1,
In the first leaching step, the powder having a size of 50 mesh to 350 mesh is supplied,
The first leaching step,
A method for selectively recovering lithium by dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds, characterized in that carried out at 150 rpm to 300 rpm at a temperature of 20 ° C to 110 ° C. In paragraph 1,
The solid-liquid separation step,
It is performed using a filter,
The second leaching solution is dried from raw materials containing lithium, aluminum and silicon compounds, characterized in that they include lithium (Li), zinc (Zn), aluminum (Al), sodium (Na) and silicon (Si). Method for selective recovery of lithium by hydrometallurgy process. In paragraph 1,
The residue is
Selective recovery method of lithium by dry/wet fusion smelting process from raw materials containing lithium, aluminum and silicon compounds, characterized in that they contain at least one of zeolite P1, zeolite LTA and sodalite . In paragraph 1,
The pH adjustment step,
A method for selectively recovering lithium from raw materials containing lithium, aluminum and silicon compounds by dry/wet fusion smelting process, characterized in that the pH of the second leaching solution is adjusted to 3 to 9. delete In paragraph 1,
The extraction solvent is (2-ethylhexyl)phosphonic acid Mono-2-ethylhexyl Ester (PC88A), di-(2-ethylhexyl)phosphoric acid (D2EHPA), bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), neodecanoic acid (Versatic 10 acid), tributyl phosphate (TBP), and trialkylphosphine oxide (Cyanex923), characterized in that selected from the group consisting of lithium, aluminum and silicon compounds in the dry and wet fusion smelting process Method for selective recovery of lithium by delete delete

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