WO2020111598A1 - Method and apparatus for manufacturing lithium sulfate solution from lithium bearing ore - Google Patents

Abstract

The present invention relates to a method and an apparatus for manufacturing a lithium sulfate solution. Specifically, the present invention provides a method for manufacturing a lithium sulfate solution and an apparatus for manufacturing a lithium sulfate solution, the method comprising: a crushing step of crushing lithium bearing ore to an average particle size of 0.5 mm or less so as to obtain and collect fine powder; a ultrafine powder collecting step of collecting ultrafine powder, in the fine powder, scattered without being collected in the crushing step; a sintering step of changing the phase of fine powder ore comprising the collected fine powder and ultrafine powder by sintering while pneumatically conveying, by means of a gas, the fine powder ore; a calcination step of calcining the phase-changed fine powder ore with a sulfuric acid so as to obtain lithium sulfate; and a leaching step of leaching the solid lithium sulfate with water so as to obtain the lithium sulfate solution, wherein the gas flows in the direction opposite to the direction of the flow of the fine powder ore.

Description

Method and apparatus for preparing lithium sulfate solution from lithium-containing ore

The present invention relates to a method and apparatus for preparing a lithium sulfate solution from lithium-containing ores.

Lithium is widely used in various industries such as secondary batteries, glass, ceramics, alloys, lubricants, and pharmaceuticals. In particular, lithium secondary batteries have recently attracted attention as a major power source for hybrid and electric vehicles, and are also used as small batteries for existing portable electronic equipment such as mobile phones and laptops, so that the market size is more than 100 times larger than today. It is predicted to grow and is receiving attention.

Such lithium is generally capable of recovering lithium from a lithium-containing ore. Lithium in the lithium-containing ore mainly exists as a mineral phase of spodumene (LiAl(Si ₂ O ₆ )), which is a dense α phase. Exists.

In order to effectively extract lithium from the lithium-containing ore, a leaching process using sulfuric acid is used. In this dense form of α-spodumene, the recovery of lithium is not effective and the lithium recovery rate is remarkably low. However, when the α-spodumene is heated to 900 to 1100° C. and converted to the β phase through the γ phase, a volume expansion of about 30% occurs. Due to this, the particle density decreases from 3.15 g/cm ³ to 2.40 g/cm ³ , cracks inside the ore particles and particle differentiation occur, and the specific surface area of the ore increases, so that it can be effectively leached into sulfuric acid. Can increase.

In the process of recovering lithium from the lithium-containing ore as described above, a rotary kiln type kiln is used for convenience of facilities and processes. In order to completely change the α-spodumene inside the kiln to β-spodumene, the kiln directly forms a flame inside the kiln to raise the temperature to 1100°C. However, due to the low thermal efficiency of the rotary kiln itself or the influence of local heating and ultrafine dust of the rotary kiln due to the size and location of the flame, a molten phase is generated on the particle surface to cause agglomeration of particles, resulting in clinker phase. Causes the same form. As a result, not only the thermal efficiency of the rotary kiln is further reduced, but also the phase transition rate of the particles is lowered, thereby reducing the efficiency of the overall process.

Furthermore, in order to crush the clinker phase as described above, a crushing machine was installed at the rear end of the kiln, but the process of collecting and reloading the fine powder discharged from the kiln of the rotary kiln method as described above is also not effective, so it is compared with the actual charging of lithium-containing ore. As the loss increases, the total lithium recovery rate decreases.

As described above, a method of extracting lithium from a lithium-containing material, such as U.S. Patent No. 4588566, has been studied, but it is insufficient for a study to increase the total lithium recovery rate.

The present invention is to solve the conventional problems, it is possible to increase the phase transition rate of the ore through the effective temperature rise of the lithium-containing ore during the process of preparing a lithium sulfate solution from the lithium-containing ore, can effectively treat the generated ultrafine powder It is to provide a method and apparatus.

According to one aspect of the present invention, the present invention is a crushing step of obtaining and collecting fine powder by crushing lithium-containing ore to an average particle size of 0.5 mm or less; An extremely fine powder collecting step of collecting scattered fine fine powder that is not collected in the crushing step among the fine powder; A sintering step of transferring the pulverized powder including the collected fine and ultrafine powders into a gas and phase-transfering them by firing; A roasting step of roasting the phase shifted spectroscopy with sulfuric acid to obtain solid lithium sulfate; And a leaching step of leaching the solid lithium sulfate with water to obtain a lithium sulfate solution, wherein the gas provides a method for preparing a lithium sulfate solution flowing in a reverse direction to the flow of the unspectralized light.

According to another aspect of the present invention, the present invention is a crushing furnace for obtaining a fine powder by crushing a lithium-containing ore; Bag filter for collecting the fine powder scattered in the crushing furnace (Bag filter); A gas-fired kiln for phase-shifting the pulverized gas as the gas flows in the opposite direction to the direction in which the pulverized powder including the fine powder and the ultra-fine powder is introduced; A gas supply source for supplying gas to the kisong kiln in the reverse direction; A roasting furnace for roasting the phase shifted spectroscopy with sulfuric acid to obtain solid lithium sulfate; And a leaching tank for leaching the solid lithium sulfate with water to obtain a lithium sulfate solution.

The present invention can achieve a uniform temperature increase and thus a phase transition rate of a lithium-containing ore uniformly compared to a conventional rotary kiln method, and the process of manufacturing a lithium sulfate solution by effectively treating extremely fine powders generated during the process Stability as well as total lithium recovery can be improved.

1 is a view schematically showing a process for preparing a lithium sulfate solution from a lithium-containing ore using a conventional rotary kiln.

2 is a view schematically showing a process for preparing a lithium sulfate solution from a lithium-containing ore according to the present invention.

3 is a view schematically showing the flow of the drying and crushing furnace and the air-fired kiln in FIG. 2.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to what is illustrated. In addition, when any part of the specification includes any component, this means that other components may be further included instead of excluding other components, unless otherwise stated.

Furthermore, in the present invention, "cyclone" refers to a "cyclone type classifier", and "cyclone" and "cyclone type classifier" can be understood to have the same meaning.

The present invention relates to a method for preparing a lithium sulfate solution from a lithium-containing ore, the method of the present invention crushing the lithium-containing ore to prepare a fine powder, calcining the fine powder, and then phase-transferring the fine-transferred fine powder into sulfuric acid. Provided is a method and apparatus for preparing a lithium sulfate solution that can be prepared by discharging and leaching with water.

Specifically, the present invention crushing step of obtaining and collecting the fine powder by crushing the lithium-containing ore to an average particle size of 0.5mm or less; An extremely fine powder collecting step of collecting scattered fine fine powder that is not collected in the crushing step among the fine powder; A sintering step of transferring the pulverized powder including the collected fine and ultrafine powders into a gas and phase-transfering them by firing; A roasting step of roasting the phase shifted spectroscopy with sulfuric acid to obtain solid lithium sulfate; And a leaching step of leaching the solid lithium sulfate with water to obtain a lithium sulfate solution, wherein the gas provides a method for preparing a lithium sulfate solution flowing in a reverse direction to the flow of the unspectralized light.

On the other hand, the present invention is a crushing furnace including a crushing device for obtaining a fine powder by crushing a lithium-containing ore; Bag filter for collecting the fine powder scattered in the crushing furnace (Bag filter); A gas-fired kiln for phase-shifting the pulverized gas as the gas flows in the opposite direction to the direction in which the pulverized powder including the fine powder and the ultra-fine powder is introduced; A gas supply source for supplying gas to the kisong kiln in the reverse direction; A roasting furnace for roasting the phase shifted spectroscopy with sulfuric acid to obtain solid lithium sulfate; And a leaching tank for leaching the solid lithium sulfate with water to obtain a lithium sulfate solution.

At this time, in the method for preparing the lithium sulfate solution, the fine powder having a particle size of more than 0.5 mm among the fine powder in the crushing step may include a step of being recycled back to the crushing step. It may include a re-crushing device for re-crushing the fine spectroscopy exceeding 0.5 mm particle size.

On the other hand, the lithium-containing ore may be at least one form selected from the group consisting of spodumene, petalite and lepidolite, preferably in the form of spodumene, more preferably Is α-spodumene.

In the step of crushing the lithium-containing ore of the present invention, the ore may be scattered while drying the ore using the gas discharged from the firing step. To this end, the lithium sulfate solution manufacturing apparatus may include a gas pipe capable of injecting gas discharged from the gas-fired kiln into the crushing furnace.

In addition, the gas may dry the ore or fine powder when crushing a lithium-containing ore. Since the ore is crushed while drying, it is possible to further improve the crushing efficiency of the ore, and can effectively scatter and separate the fine powder.

In detail, the method and apparatus for manufacturing the lithium sulfate solution are as shown in FIG. 2, and lithium-containing ore (fine powder) crushed to a certain size or less through a crushing furnace 70 for processing a lithium-containing ore to a certain particle size, and the It is possible to charge the blast furnace 80 with pulverized spectroscopy including extremely fine powder collected in the bag filter 75 by being scattered with gas among the fine powder.

The fine spectroscopy injected into the air-fired firing furnace 80 is gradually heated while being heated with the gas supplied by the gas supply source 85, so that the α phase of the pulverization can be effectively phase-transferred to the β phase.

Furthermore, the gas supplied by the gas supply source 85 may have a temperature of 1000 to 1300°C, preferably a temperature of 1000 to 1200°C, and most preferably a temperature of 1100°C. At this time, when the gas is less than 1000°C, the temperature is low, so the phase transition speed of undifferentiated is delayed, so that effective phase transition may not occur between the air-transporting furnaces 80, and if the temperature exceeds 1300°C, the particles are due to high temperature. Due to the formation of the melt inside, agglomerates are formed between ore particles, so that the particles become large and the transport is not smooth, or the particles become large due to lumping, so there is a problem that effective phase transition cannot occur due to the inability to increase the temperature inside the larger particles.

More specifically, as shown in FIG. 3, the crushing furnace 70 crushes lithium-containing ore having various particle size distributions supplied from the charging bin 1 with a crusher (for example, a hammer mill 71 is installed). Differentiation can be obtained. At this time, the lithium-containing ore may be crushed while being dried with a gas discharged from the gas-fired firing furnace 80 and injected into the crushing furnace 70.

The fine powder is discharged from the gas-fired firing furnace 80 and scattered along with the gas injected into the crushing furnace 70 and supplied to the cyclone classifier 72. At this time, the fine particles exceeding the particle size of 0.5 mm in the supplied gas can be collected in the classifier 72 and recycled to the crusher 71 through the recirculation pipe 77, while the particle size not collected in the classifier is 0.5 mm. The following fine powder may be discharged to the outside of the classifier 72 to be supplied to and collected in a dusting classifier (Dedusting Cyclone 73).

Since the fine particles having a particle size of more than 0.5 mm recirculated to the crusher 71 are again crushed in the crusher 71 and scattered with the gas to the classifier 72, the fine particles having a particle size of 0.5 mm or less are discharged from the classifier 72. It can be supplied to the dust extraction classifier 73 and collected.

On the other hand, since the fine powder having a particle size of 0.1 mm or less among the fine particles having a particle size of 0.5 mm or less supplied to the dedusting classifier 73 is not collected by the dedusting classifier 73, it is discharged together with the gas from the dedusting classifier 73. It is supplied as a filter (bag filter, 75), it can be collected in all. At this time, the gas of the crushing furnace 70 from which the ultrafine powder is removed from the bag filter 75 may be discharged to the outside.

The pulverized powder including the fine powder collected by the dust-sorting classifier 73 and the ultra-fine powder collected by the bag filter 75 may be supplied to the air-fired firing furnace 80. As a result, the crushing furnace 70 can supply the dried pulverization of 0.5 mm or less to the air-fired firing furnace 80.

Furthermore, as shown in FIG. 3, the undivided spectral introduced into the air-fired firing furnace 80 is stored in a dry light bin 90 and discharged at a constant speed through a screw feeder 100 to the air-fired firing furnace 80. It can be charged with an inner cyclone. The discharged fine spectroscopy is charged into the cyclone in the gas-fired firing furnace 80 through the gas-transmitting gas supply pipe 89, and is uniformly heated while undergoing a multi-stage cyclone connected in series with the gas supply source 85 to undergo phase change.

The firing step of the present invention may be performed through the multi-stage cyclone, and the firing step includes a first classification step to a third classification step, and in each classification step, the flow of pulverized gas and the flow of gas are reversed. A first classifying step performed by sending the unspectralized gas to the gas discharged in the second classifying step; A second classification step performed by sending the undiluted light recovered in the first classification step to the gas discharged in the third classification step; It may be carried out by including a third classification step is carried out by sending the pulverized recovered from the second classification step to the gas discharged from the gas source.

Specifically, the air-fired kiln 80 may include three cyclones, and the three cyclones may be connected in series.

At this time, the undivided spectral inputted to the air-fired kiln 80 flows in the order of the first cyclone 81, the second cyclone 82, and the third cyclone 83, and is sequentially heated, while being generated from the gas source 85 The gas is flowed from the gas source 85 in the order of the third cyclone 83, the second cyclone 82, and the first cyclone 81, as opposed to the pulverization, and the temperature is sequentially lowered. Furthermore, the undiluted dust recovered from the third cyclone 83 may be injected into the roasting furnace 30.

Therefore, the gas of the gas-fired kiln 80 is discharged to the crushing furnace 70 while passing through the third, second, and first cyclones, while the undivided spectral input to the gas-fired kiln 80 is the opposite of the gas. The temperature is raised while passing through the 1st, 2nd, and 3rd cyclones, and finally recovered from the 3rd cyclone 83.

For example, as shown in FIG. 3, the undivided spectral discharged at a constant rate through the screw feeder 100 from the dry light bin 90 mixes some branched gas and air from the heat source 85 to a constant temperature. It can be charged as a multi-stage cyclone through the gas transport gas supply pipe 89 with the gas adjusted to a constant temperature by adjusting the air mixing ratio in a gas or a small gas burner controlled by.

The pulverized charge charged through the transport gas supply pipe 89 is injected into the first cyclone 81 while transporting the gas discharged from the second cyclone 82.

The fine spectroscopy injected into the first cyclone 81 together with the gas is recovered separately from the gas, and the recovered spectroscopy is injected into the second cyclone 82 together with the gas discharged from the third cyclone 83.

The fine spectroscopy injected into the second cyclone 82 together with the gas is recovered separately from the gas, and the recovered fine spectroscopy is injected into the third cyclone 83 together with the gas discharged from the gas source 85.

The fine spectroscopy injected with the gas into the third cyclone 83 is separated from the gas and recovered, and the recovered spectroscopy is stored in the calcined light bin 84.

When passing through the kisong firing furnace 80 of the present invention as described above, the undifferentiated charge charged in the firing light bin 84 may be gradually elevated while gradually increasing temperature. That is, unlike the conventional rotary kiln type kiln 10, the air-fired kiln 80 of the present invention uses only gas generated from the gas supply source 85 to transport undifferentiated particles having a certain particle size (0.5 mm) or less as gas. As it is gradually heated, the molten phase in the particles due to local overheating is formed by the flame of the burner installed for heating inside the rotary kiln, thereby inhibiting agglomeration between particles or generation of clinker phase.

Therefore, since the temperature rise and uniform phase transition of the uniform particles are completed, the phase transition efficiency is increased, and the firing process is not only stable, but also the sulfuric acid roasting, leaching and impurity removal reaction (precipitation) is effectively performed after firing without separate crushing process. Recovery rates may increase.

In the roasting step and roasting, the phase shifted pulverization is injected into the rotary kiln 30 and sulfuric acid is injected into the rotary kiln 30 through a sulfuric acid injection tube 35 to roast the phase-shifted microscopic spectroscopy to form solid sulfuric acid. It is to obtain lithium (Li ₂ SO ₄ ).

Furthermore, in the leaching step and the leaching tank, the solid lithium sulfate (Li ₂ SO ₄ ) is introduced into water by injecting the solid lithium sulfate into the leaching tank 40 and injecting water 45 into the leaching tank 40. It is to prepare a lithium sulfate solution by leaching. The reaction for obtaining the solid phase lithium sulfate from the phase shifted spectroscopy is as follows.

2LiAl(Si ₂ O ₆ )(s) + H ₂ SO ₄ (l) → 2HAlSi ₂ O ₆ (s)+ Li ₂ SO ₄ (s)

At this time, the roasting process is preferably performed at a temperature of 200 to 250 ℃.

Furthermore, the prepared lithium sulfate solution may remove impurities contained in the solution through an impurity removal reaction. The impurity removal reaction injects the lithium sulfate solution into the precipitation furnace 50 and injects a precipitant 55 into the injected lithium sulfate solution to remove impurities such as Al, Si, Ca and Mg present in the lithium sulfate solution. It is to be removed by the precipitate (56).

As a result, the present invention enables uniform temperature increase of lithium-containing ore compared to the conventional rotary kiln method, thereby achieving a high phase transition rate, and effectively treating scattering of extremely fine particles generated during the process. Compared to the manufacturing process of lithium sulfate, scattering loss of extremely fine powder can be suppressed, so that the total lithium recovery rate can be improved.

Hereinafter, the present invention will be described in more detail through specific examples. The following examples are only examples for helping the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

Table 1 summarizes the composition and particle size distribution of the lithium-containing ore used in the Examples of the present invention.

ingredient		Composition (wt%)
Li		3.13
Ca		0.61
Mg		0.40
Mn		0.15
Al		13.04
Si		29.37
P		0.01
Fe		1.31
Na		0.38
K		0.84
Particle size (mm)	-1.18	0.8
	+1.18	29.4
	+4.75	36.1
	+9.5	33.8

As shown in Table 1, the lithium-containing ore used contains 3.13 wt% of Li and contains a large amount of gangue components such as Al and Si, and the main mineral phases are α-spodumene (LiAlSi ₂ O ₆ ), quartz (quartz, SiO ₂ ), etc. were detected, and there were few fine powders with a particle size of 1.18 mm or less, and most of them had a particle size of 4.75 mm or more, indicating that they were relatively large spectroscopy. The result of using the lithium-containing ore having the composition shown in Table 1, using the existing rotary kiln (Rotary Kiln) calcination furnace and a crushing machine using a lithium sulfate solution manufacturing apparatus (the apparatus of FIG. 1) to produce a lithium sulfate solution Was used as Comparative Example 1.

In addition, the result of preparing a lithium sulfate solution through the apparatus for producing a lithium sulfate solution of the present invention (the devices of FIGS. 2 and 3) was set to Example 1.

At this time, the temperature of the gas was maintained at 1070°C, and the temperature of the roasting furnace was maintained at 250°C. Table 2 summarizes the results of analyzing the components of the lithium sulfate solution prepared using the existing lithium sulfate solution preparation device and the present invention lithium sulfate solution preparation device.

division		Comparative Example 1	Example 1
Phase transition rate (%)		77.1	100
Chemical analysis (g/L)	Li	11.59	12.81
	Ca	0.024	0.021
	Mg	0.003	0.003
	Mn	<0.003	<0.003
	Al	<0.003	<0.003
	Si	0.003	0.003
	P	0.003	0.003
	Fe	<0.003	<0.003
	Na	4.35	4.12
	K	0.642	0.572
	S	28.72	31.72
Total lithium recovery rate (%)		81.8	90.4

As shown in Table 2, compared to Comparative Example 1, the recovery amount of lithium in Example 1 was significantly increased from 11.59 g/L to 12.81 g/L, and accordingly, the total lithium recovery rate was also increased from 81.8% to 90.4%. Although the embodiments of the present invention have been described in detail above, the scope of rights of the present invention is not limited thereto, and various modifications and variations are within the scope of the technical spirit of the present invention as set forth in the claims. This will be apparent to those skilled in the art.

[Description of codes]

1: Jang Jang Bin 10: Soseongro

20: crushing furnace 30: roasting furnace

40: leaching furnace 50: sedimentation furnace

70: crushing furnace 80: Kisong firing furnace

71: shredder 72: classifier

73: exhaustion classifier 75: Bag Filter

77: recirculation pipe 81, 82, 83: 1, 2, 3 cyclone

84: firing light bin 85: heat source (Burner)

86, 87, 88: 1st, 2nd, 3rd cyclone recovery pipe 89: Transport gas supply pipe

90: dry light bin 100: screw feeder

Claims (14)

1. A crushing step of obtaining and collecting fine powder by crushing the lithium-containing ore to an average particle size of 0.5 mm or less;

   An extremely fine powder collecting step of collecting scattered fine fine powder that is not collected in the crushing step among the fine powder;

   A sintering step of transferring the pulverized powder including the collected fine and ultrafine powders into a gas and phase-transfering them by firing;

   A roasting step of roasting the phase shifted spectroscopy with sulfuric acid to obtain solid lithium sulfate; And

   A leaching step of leaching the solid lithium sulfate with water to obtain a lithium sulfate solution,

   The gas is a method for producing a lithium sulfate solution, flowing in the reverse direction of the flow of the spectral.
2. The method of claim 1, wherein the crushing step pulverizes by recycling the fine powder having a particle size of more than 0.5 mm.
3. The method of claim 1, wherein the lithium-containing ore is at least one form selected from the group consisting of spodumene, petalite and lepidolite.
4. The method of claim 1, wherein the gas that has undergone phase change of the pulverization in the firing step flows into the crushing step.
5. The method of claim 1, wherein the gas is a temperature of 1000 to 1300°C.
6. The method of claim 1, wherein the firing step includes a first classification step to a third classification step, and in each classifying step, the flow of pulverized gas and the flow of gas are reversed.

   A first classification step performed by sending the unspectralized light to the gas discharged in the second classification step; A second classification step performed by sending the undiluted light recovered in the first classification step to the gas discharged in the third classification step; A method for producing a lithium sulfate solution, which is carried out, including a third classification step performed by sending the undivided spectral collected in the second classification step to a gas discharged from a gas source.
7. The method of claim 1, wherein the roasting step is performed by sulfuric acid at 200 to 250°C.
8. A crushing furnace including a crushing device for pulverizing lithium-containing ore to obtain fine powder;

   Bag filter for collecting the fine powder scattered in the crushing furnace (Bag filter);

   A gas-fired kiln for phase-shifting the pulverized gas as the gas flows in the opposite direction to the direction in which the pulverized powder including the fine powder and the ultra-fine powder is introduced;

   A gas supply source supplying gas to the kisong kiln;

   A roasting furnace for roasting the phase shifted spectroscopy with sulfuric acid to obtain solid lithium sulfate; And

   And a leaching tank for leaching the solid lithium sulfate with water to obtain a lithium sulfate solution.
9. The apparatus for manufacturing a lithium sulfate solution according to claim 8, wherein the crushing furnace includes a recirculation pipe for supplying fine particles having a particle size of more than 0.5 mm to the crushing device.
10. The apparatus for manufacturing a lithium sulfate solution according to claim 8, wherein the lithium-containing ore is at least one form selected from the group consisting of spodumene, petalite and lepidolite.
11. The apparatus for manufacturing a lithium sulfate solution according to claim 8, comprising a gas pipe for injecting gas discharged from the gas-fired kiln into the crushing furnace.
12. The apparatus of claim 8, wherein the gas is 1000 to 1300°C.
13. 9. The method of claim 8, wherein the air-fired kiln comprises three classifiers;

    The three classifiers are connected in series, and the pulverized dust inputted to the air-fired kiln flows in order of a first cyclone, a second cyclone and a third cyclone, and the gas generated from the gas source is a third cyclone from the gas source, A device for producing a lithium sulfate solution, which flows in the order of the second cyclone and the first cyclone, and the pulverized dust recovered from the third cyclone is injected into the roasting furnace.
14. The method of claim 12, wherein the pulverized spectroscopy is injected into the first cyclone while being transported as a gas discharged from the second cyclone, and the pulverized separated and recovered from the first cyclone is discharged from the third cyclone. An apparatus for producing a lithium sulfate solution, which is injected into the second cyclone while being transported as gas, and is injected into the third cyclone while being transported as gas discharged from a gas source.

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