KR20240165512A - Apparatus for mass production of lithium sulfide - Google Patents

Abstract

The lithium sulfide mass production device according to the present invention relates to a device for economically mass-producing lithium sulfide, and comprises: a reaction chamber having a reaction space for producing lithium sulfide and provided with a lithium raw material; a hydrogen sulfide supply unit provided to supply hydrogen sulfide to the reaction chamber; a heating unit provided to heat the reaction space; a lithium sulfide recovery unit provided to remove impurities from lithium sulfide generated by a reaction between hydrogen sulfide and a lithium raw material in the reaction chamber and to recover only pure lithium sulfide; a condensation unit for recovering and condensing gas discharged from the reaction chamber; a solvent re-supply unit for receiving a mixture from the condensation unit, selecting a reaction solvent, and supplying the solvent into the reaction chamber; and a moisture removal unit provided to remove water vapor from the recovered gas delivered from the solvent re-supply unit and then supply only hydrogen sulfide gas to the bottom of the reaction chamber, a hydrogen sulfide supply unit, or a hydrogen sulfide supply line.

Description

{APPARATUS FOR MASS PRODUCTION OF LITHIUM SULFIDE}

The present invention relates to an apparatus for economically mass producing lithium sulfide.

Lithium secondary batteries have the characteristics of high energy density and long lifespan, so they are widely used in electronic devices such as home appliances, laptop computers, and smartphones, and recently, their utilization is greatly increasing as they are installed in electric vehicles (EVs) and hybrid electric vehicles (HEVs).

Lithium-ion secondary batteries, which are mainly used today, have been widely used as the main power source for mobile phones, laptops, and PCs since mass production began in 1991 due to their high energy density and output voltage. However, the organic electrolyte provided for the smooth movement of lithium ions carries the risk of explosion in cases of overheating and overcharge, and can easily catch fire if there is a source of ignition, and when side reactions occur inside the battery, there may be problems with the deterioration of battery performance and stability due to gas generation.

Accordingly, to overcome the shortcomings of lithium ion secondary batteries, active research and development is being conducted on lithium all-solid secondary batteries. Lithium all-solid secondary batteries not only reduce the risk of explosion by using a solid electrolyte instead of a volatile electrolyte, but also have the advantage of dramatically improving the energy density of the battery because lithium metal or lithium alloy can be used as the negative electrode material.

Today, among the solid electrolyte candidates that can be mounted on all-solid-state batteries, sulfide-based solid electrolytes known to have high ductility and high ionic conductivity are evaluated as suitable for manufacturing high-capacity, large-scale secondary batteries, and lithium sulfide (Li ₂ S) is evaluated as a key material in the manufacturing process of such sulfide-based solid electrolytes. Various methods are known to synthesize lithium sulfide, but the most common method is known to be the reaction of lithium metal, such as lithium hydroxide (LiOH) or lithium carbonate (Li ₂ CO ₃ ), with hydrogen sulfide (H ₂ S).

Meanwhile, hydrogen sulfide gas is a highly corrosive gas, and when reacted with metallic lithium in a conventional metal reactor, it corrodes the reactor and various piping and other equipment, requiring frequent repairs and replacements, which reduces the economic feasibility of mass production of lithium sulfide.

In addition, when lithium metal such as lithium hydroxide is reacted with hydrogen sulfide, water vapor is inevitably generated. The water vapor generated at this time not only interferes with the contact between the lithium metal and hydrogen sulfide, reducing the yield of lithium sulfide, but also reacts again with lithium sulfide to accelerate the reverse reaction into lithium hydroxide, thereby lowering the purity of the manufactured lithium sulfide. In addition, moisture can cause agglomeration between the manufactured lithium sulfide particles, which can result in a decrease in quality.

Accordingly, the inventors of the present invention have studied a method for improving economic efficiency by utilizing a reaction of reacting metallic lithium and hydrogen sulfide to produce lithium sulfide, while producing lithium sulfide in large quantities under relatively mild conditions, and removing moisture from unreacted hydrogen sulfide and reusing it for producing lithium sulfide, and as a result, have completed the present invention.

The present invention has been proposed to solve the above problems, and provides a device for mass-producing lithium sulfide with high purity and high yield by designing a reactor with specific material and temperature conditions suitable for mass-producing lithium sulfide through a reaction between metallic lithium and hydrogen sulfide, and further selectively removing water vapor from a gas generated during the reaction and then re-supplying hydrogen sulfide into the reactor.

In one example, a lithium sulfide mass production device includes: a reaction chamber having a reaction space for producing lithium sulfide, and provided with a lithium raw material; a hydrogen sulfide supply unit provided to supply hydrogen sulfide to the reaction chamber; a heating unit provided to heat the reaction space; a lithium sulfide recovery unit provided to remove impurities from lithium sulfide generated by a reaction between hydrogen sulfide and the lithium raw material in the reaction chamber and to recover only pure lithium sulfide; a condensation unit that recovers and condenses gas discharged from the reaction chamber; a solvent re-supply unit that receives a mixture from the condensation unit, selects a reaction solvent, and supplies the solvent into the reaction chamber; and a moisture removal unit provided to remove water vapor from the recovery gas delivered from the solvent re-supply unit and then supply only hydrogen sulfide gas to the bottom of the reaction chamber, a hydrogen sulfide supply unit, or a hydrogen sulfide supply line.

In another example, a stirring member may be further provided within the reaction chamber to promote a reaction between the supplied hydrogen sulfide and the lithium raw material.

In another example, the reaction chamber can be made of one or more materials selected from the group consisting of Hastelloy X, stainless steel 304 (SUS 304), stainless steel 310 (SUS 310), stainless steel 316 (SUS 316), alumina, quartz, and combinations thereof.

In another example, the heating unit may be mounted on the outer surface of the reaction chamber to heat the temperature of the reaction space to 120° C. or higher and less than 300° C.

In another example, the lithium raw material supplied to the reaction chamber may have a particle size of 1 mm or less.

In another example, the solvent resupply unit may be a Dean-Stark trap.

In another example, the moisture removal unit may be a sublimation cooling unit that cools the gas recovered from the solvent resupply unit and selectively removes only moisture from the gas.

In another example, the sublimation cooling unit may include a plurality of cooling chambers and a control unit that controls the sublimation cooling unit, and the control unit may control cooling to be performed in the cooling chamber to which the recovery gas is transferred when the recovery gas is transferred to at least one cooling chamber set among the plurality of cooling chambers.

In another example, the control unit may control the cooling chamber into which the recovery gas is transferred to be transferred to another cooling chamber after the cooling operation has been performed for a predetermined period of time, and may cause heating to be performed on the cooling chamber that has been subjected to the cooling operation for the predetermined period of time, thereby liquefying and removing ice sublimated by the cooling.

In another example, the sublimation cooling unit may have a plurality of branch lines for respectively transporting the recovery gas to the plurality of cooling chambers, and a valve installed in the branch lines to open and close each of the branch lines, and the control unit may be configured to determine the cooling chamber to which the recovery gas is transported by controlling the valves.

In another example, the sublimation cooling unit has a body that is arranged to be rotatable around an axis parallel to a direction in which the recovery gas is transported, and the plurality of cooling chambers are formed penetrating the body along a direction parallel to the axis, at least one of which is arranged to communicate with a recovery line through which the recovery gas is transported and a resupply line through which the recovery gas is re-supplied to the reaction chamber, and the control unit can control the cooling chamber performing the cooling to be communicated with the recovery line and the resupply line by rotating the body around the axis.

In another example, the control unit controls the recovery line to be connected to another cooling chamber scheduled to be subjected to cooling operation by rotating the main body around an axis after the cooling chamber into which the recovery gas is transferred has been subjected to cooling operation for a predetermined period of time, and causes heating to proceed with the cooling chamber that has been subjected to cooling operation for the predetermined period of time, thereby liquefying and removing ice sublimated by cooling.

According to the present invention, when producing lithium sulfide through a reaction between metallic lithium and hydrogen sulfide, the reaction is performed under relatively mild conditions compared to conventional techniques, so frequent repairs or replacements due to corrosion and fixation of the reactor and various piping are not required, thereby improving the economic efficiency of the process.

In addition, water vapor (moisture), a by-product of the reaction, is effectively removed, preventing reverse reaction into lithium hydroxide and promoting the forward reaction, while preventing agglomeration between lithium sulfide particles, thereby enabling mass production of high-quality lithium sulfide with high purity and high yield.

Furthermore, by re-supplying the reaction solvent and unreacted hydrogen sulfide into the reaction chamber, the hydrogen sulfide reaction rate can be improved, thereby ensuring the economic feasibility of the process.

FIG. 1 is a schematic diagram showing a mass production device for lithium sulfide according to one embodiment of the present invention.
FIG. 2 is a perspective view showing a sublimation cooling unit according to one embodiment of the present invention.
FIG. 3 is a perspective view showing a sublimation cooling unit according to another embodiment of the present invention.
FIG. 4 is a front view showing a sublimation cooling unit according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same numerals as much as possible even if they are shown in different drawings. In addition, when describing embodiments of the present invention, if it is determined that a specific description of a related known configuration or function hinders understanding of the embodiments of the present invention, the detailed description thereof will be omitted.

FIG. 1 is a schematic diagram showing a mass production device for lithium sulfide according to one embodiment of the present invention. Hereinafter, a mass production device for lithium sulfide according to one embodiment of the present invention will be described with reference to FIG. 1.

A lithium sulfide mass production device according to one embodiment of the present invention includes a reaction chamber (100), a heating unit (150), a hydrogen sulfide supply unit (200), a condensation unit (300), a solvent resupply unit (400), a moisture removal unit (500), and a lithium sulfide recovery unit (600). Meanwhile, although not shown, a separately provided supply means such as a circulation pump may be used as a means for promoting material movement between each component within the production device.

The reaction chamber (100) is a chamber having a reaction space for producing lithium sulfide. Lithium raw material and hydrogen sulfide react in the reaction space to synthesize lithium sulfide. A reaction solvent for inducing a wet reaction may be provided inside the reaction chamber (100), and specifically, the reaction solvent may be selected from hexane, octane, decane, dodecane, toluene, xylene (o, m, p-xylene), and combinations thereof, or may be a non-polar solvent. Meanwhile, the method for supplying the lithium raw material is not particularly limited, and for example, it may be supplied in the form of being charged into the reactor all at once, or it may be supplied by installing a conveyor belt or the like outside the reaction chamber (100) to implement an automated/semi-automated process, and also, the lithium raw material supply line (10) supplied to the reaction chamber (100) may be formed to be inclined so that the lithium raw material moves into the reaction chamber by gravity. In addition, it can be moved using a blower or other ventilation means. Meanwhile, a stirring member (not shown) for promoting the reaction may be further provided inside the reaction chamber, and for example, a rotating disk, a rotary, a propeller, etc. may be employed, but is not particularly limited.

The hydrogen sulfide supply unit (200) is provided to supply hydrogen sulfide to the reaction chamber (100). Specifically, the hydrogen sulfide supply unit (200) is provided adjacent to the lower side of one side of the reaction chamber so as to supply hydrogen sulfide into the reaction chamber. Meanwhile, an in-line disperser (not shown) for generating bubbles in hydrogen sulfide may be provided in the hydrogen sulfide supply line (20) between the hydrogen sulfide supply unit and the reactor. The in-line disperser may be a device that mixes fluids supplied by the high-speed rotation of the rotor at high pressure, and the in-line disperser may be controlled to have an optimal pressure and temperature range for supplying hydrogen sulfide in a bubbling state.

Meanwhile, the lithium raw material provided in the reaction chamber may be lithium hydroxide (LiOH) or lithium carbonate (Li ₂ CO ₃ ), specifically lithium hydroxide. Specifically, lithium hydroxide supplied to the reaction chamber (100) may react with hydrogen sulfide to produce lithium sulfide as shown in Equation 1 below. That is, it can be seen that when lithium hydroxide and hydrogen sulfide react, water is produced as a byproduct.

2LiOH + H ₂ S → Li ₂ S + 2H ₂ O <Formula 1>

According to one embodiment of the present invention, the lithium raw material supplied may have a particle size of 1 mm or less. Accordingly, it is possible to produce high-purity lithium sulfide by increasing the reaction area with hydrogen sulfide.

Meanwhile, the heating unit (150) is configured to heat the reaction space. The method by which the heating unit (150) heats the reaction space is not particularly limited. For example, the heating unit (150) may be a heater, a heating wire, or an infrared heater mounted on the outer surface of the reaction chamber (100).

In addition, the heating unit (150) can heat the temperature of the reaction space to 120°C or more and less than 300°C, specifically 140°C or more and less than 300°C, and more specifically 160°C or more and less than 300°C. In order for the lithium raw material and hydrogen sulfide to react smoothly, the lithium raw material (lithium hydroxide) needs to be sufficiently heated. In addition, as described above, water (H ₂ O) is generated as a by-product by the reaction of lithium hydroxide and hydrogen sulfide, and if water exists in a liquid state, there is a concern that the water may flow between lithium hydroxide particles, reducing the area of lithium hydroxide reacting with hydrogen sulfide. Therefore, by heating the temperature of the reaction space to 120°C, specifically 140°C, and more specifically 160°C or more to evaporate the water, high-purity lithium sulfide can be obtained.

Meanwhile, the higher the temperature of the reaction space, the more the reaction between lithium hydroxide and hydrogen sulfide can be promoted. However, since the melting point of lithium hydroxide is 445℃, it is preferable that the temperature of the reaction space does not exceed 445℃.

In addition, as the temperature of the reaction space increases, there is a greater risk of corrosion of the inner surface of the reaction chamber (100) by hydrogen sulfide. Therefore, the reaction chamber (100) may be manufactured from a material having strong heat resistance and corrosion resistance. For example, the reaction chamber (100) may be made of at least one material selected from the group consisting of Hastelloy X, stainless steel 304 (SUS 304), stainless steel 310 (SUS 310), stainless steel 316 (SUS 316), alumina, quartz, and combinations thereof. In addition, the heating unit (150) can heat the temperature of the reaction space to less than 300° C. Accordingly, frequent repair or replacement of equipment such as piping including the reaction chamber (100) can be prevented, and the reaction between hydrogen sulfide and the lithium raw material can be sufficiently promoted to obtain high-purity lithium sulfide.

A condenser (300) may be provided to recover gas discharged from the reaction chamber (100) along the exhaust line (40) and condense it, and a separate cooling means (not shown) may be provided for this purpose. The condenser may be configured as a condenser utilizing a heat exchange method, for example.

The solvent resupply unit (400) may be configured to receive the mixture from the condensation unit, selectively separate only the reaction solvent through distillation or the like, and resupply the separated reaction solvent into the reaction chamber (100). Meanwhile, the mixture delivered from the condensation unit may be in a form in which a gas and a liquid phase are mixed, and specifically, may be a mixture in which hydrogen sulfide (H ₂ S), the reaction solvent, and water vapor (H ₂ O) are mixed. As a specific example, the solvent resupply unit (400) may be a Dean-Stark trap, and when the Dean-Stark trap is applied, the reaction solvent and water are separated from the mixture by the difference in specific gravity, and the separated reaction solvent is supplied back to the reaction chamber along the solvent resupply line (60), and the water may be primarily removed along the discharge line (515).

The lithium sulfide recovery unit (600) may further include a filter member (F) as a configuration for recovering lithium sulfide and removing impurities to further increase the purity of the lithium sulfide. For example, lithium sulfide generated by the reaction between hydrogen sulfide and lithium raw material in the reaction chamber (100) may be recovered through the lithium sulfide recovery line (30) and then filtered by the filter member (F) to remove impurities. Meanwhile, the lithium sulfide recovery line (30) may be provided to be in communication with the bottom of the reaction chamber (100). Here, the bottom of the reaction chamber (100) may mean the area below the reaction space heated by the heating unit (150). The structure of the lithium sulfide recovery unit (600) is not particularly limited. For example, the recovery unit may have a chamber configuration in a shape such as a square or rectangle, a cylinder, or an inverted cone to effectively recover lithium sulfide. Meanwhile, the filter member (F) may be made of one or more materials selected from among Hastelloy, stainless steel 304 (SUS 304), stainless steel 310 (SUS 310), stainless steel 316 (SUS 316), and combinations thereof, and may be in the form of a mesh.

Meanwhile, Fig. 2 is a schematic diagram showing a moisture removal unit according to one embodiment of the present invention. Hereinafter, a moisture removal unit (500) according to one embodiment of the present invention will be described with reference to Figs. 1 and 2 to 4.

The moisture removal unit (500) is provided to remove water vapor from the recovery gas delivered from the solvent resupply unit (400), and then supply only the hydrogen sulfide gas from which the water vapor has been removed back to the bottom of the reaction chamber (100), the hydrogen sulfide supply unit (200) or the hydrogen sulfide supply line (20). As described above, in the reaction chamber (100), unreacted hydrogen sulfide that has not yet reacted with the lithium raw material, water vapor generated by the reaction of hydrogen sulfide and lithium hydroxide, and the gasified reaction solvent can be discharged, and the reaction solvent and water are removed while passing through the condenser (300) and the solvent resupply unit (400). Thereafter, most of the recovery gas delivered from the solvent resupply unit (400) to the moisture removal unit (500) contains only hydrogen sulfide gas, but a very small amount of water vapor that has not yet been removed may also be included. Therefore, there is a need to completely remove water vapor from the recovery gas and supply it back to the reaction chamber (100).

To this end, the recovered gas delivered from the solvent resupply unit (400) through the recovery line (45) may be delivered to the moisture removal unit (500). Meanwhile, a separate supply means such as a circulation pump (not shown) may be additionally provided to resupply the hydrogen sulfide gas from which water vapor has been removed in the moisture removal unit.

Specifically, referring to FIG. 2, the moisture removal unit (500) may be a sublimation cooling unit (520) that cools the gas recovered from the solvent resupply unit and selectively removes only moisture from the recovered gas.

Meanwhile, the sublimation cooling unit (520) may be configured to cool the gas recovered from the solvent resupply unit (400) to secondarily remove moisture. For example, the water vapor may be sublimated and removed by cooling the water vapor to about -30°C. The sublimation cooling unit (520) may recover the gas that has passed through the solvent resupply unit (400) through the recovery line (45) to additionally remove the water vapor (water) that has not been removed in the solvent resupply unit (400). Meanwhile, the terms "primary" and "secondary" used throughout the present specification and claims should be understood as having been arbitrarily assigned a sequence for the sake of distinction. Meanwhile, primary cooling and secondary cooling do not imply the order of cooling.

To explain in more detail, the sublimation cooling unit (520) may include a cooling chamber (521), a cooling means (525) provided in the cooling chamber (521), and a control unit (not shown) that controls the sublimation cooling unit (520). The control unit may be a control unit that controls a lithium sulfide mass production device.

The water vapor supplied to the cooling chamber (521) is sublimated by the cooling means (525) and freezes on the inner surface of the cooling chamber (521), and since hydrogen sulfide has a boiling point of -59.6°C, it can pass through the cooling chamber (521) as is. Accordingly, the cooling chamber (521) can remove only the water vapor from the recovery gas and supply the hydrogen sulfide back to the reaction chamber (100).

However, since the sublimation cooling unit (520) causes a phase change by sublimating water vapor into an ice state and freezes it on the inner surface of the cooling chamber, in order to remove the water frozen on the inner surface of the cooling chamber (521), it is necessary to heat the cooling chamber (521) again to liquefy it. In other words, if only one cooling chamber (521) is provided, the operation of the lithium sulfide mass production device must be stopped in order to heat the cooling chamber (521), which makes it difficult to continuously proceed with the process.

Therefore, the sublimation cooling unit (520) according to one embodiment of the present invention may be provided with a plurality of cooling chambers (521a, 521b), a plurality of branch lines (46) for transferring the recovery gas to each of the plurality of cooling chambers (521a, 521b), and a plurality of second branch lines (48) for supplying the gas in the plurality of cooling chambers (521) to the resupply line (50). The resupply line (50) refers to a line that resupplied the recovery gas to the bottom of the reaction chamber (100), the hydrogen sulfide supply unit (200), or the hydrogen sulfide supply line (20). In addition, the control unit may control cooling to be performed in the cooling chamber to which the recovery gas is transferred when the recovery gas is transferred to a preset cooling chamber among the plurality of cooling chambers (521).

Each of the branch lines (46a, 46b) and the second branch line (48a, 48b) may be provided with first to fourth branch valves (47a, 47b, 49a, 49b). The control unit may be configured to determine the cooling chambers (521a, 521b) to which the recovery gas is transferred by controlling the branch valves (47a, 47b, 49a, 49b) provided in the branch lines (46a, 46b) and the second branch line (48a, 48b). For example, in order to transfer the recovery gas to the cooling chamber (521a) located on the upper side of FIG. 2, the first branch valve (47a) and the third branch valve (49a) may be opened, and the second branch valve (47b) and the fourth branch valve (49b) may be closed.

After the upper cooling chamber (521a) to which the recovery gas is transferred has been cooled for a predetermined period of time, it is necessary to heat and remove the ice frozen on the inner wall of the cooling chamber (521a) by sublimation. In this case, the control unit can operate the cooling means (not shown) provided in the lower cooling chamber (521b) so that the lower cooling chamber (521b) performs cooling, and then control the recovery gas to be transferred to the lower cooling chamber (521b). That is, the first branch valve (47a) and the third branch valve (49a) can be closed, and the second branch valve (47b) and the fourth branch valve (49b) can be opened, thereby controlling the recovery gas to be transferred to the lower cooling chamber (521b). Accordingly, not only can lithium sulfide be continuously manufactured without stopping the lithium sulfide manufacturing device, but also the manufacturing efficiency of lithium sulfide can be improved by additionally removing moisture from the recovery gas, and high-purity lithium sulfide can be obtained.

Meanwhile, the control unit can liquefy and remove ice sublimated by cooling by switching the upper cooling chamber (521a) that has been subjected to cooling operation for a predetermined time to heating. A separate heating means may be provided in the cooling chamber (521), and moisture can be removed simply by stopping the operation of the cooling means (525) and positioning the cooling chamber (521) at room temperature. The removed moisture can be transferred to the discharge unit (515') and removed.

In addition, instead of providing branch valves (47a, 47b, 49a, 49b) in each branch line (46a, 46b, 48a, 48b), three-way valves (not shown) may be provided at the branch points of the recovery line (45) and the branch line (46) and at the branch points of the branch line (48) and the resupply line (50). The control unit may also control the three-way valves to determine the chamber to which the recovery gas is transferred.

In addition, the number of cooling chambers (521) is not particularly limited. When three or more cooling chambers (521) are provided, cooling can be performed simultaneously in multiple cooling chambers (521). The number of cooling chambers (521) can be appropriately provided depending on the amount of water vapor generated based on the size of the reaction chamber (100), the temperature at which the heating unit (150) heats the reaction space, etc.

FIG. 3 is a perspective view showing a sublimation cooling unit according to another embodiment of the present invention. The sublimation cooling unit (520') according to another embodiment of the present invention is different from the sublimation cooling unit (520) according to the above-described embodiment in that it has a main body (523) that is arranged to be rotatable around an axis (C) parallel to the direction in which the recovery gas is transported. In addition, a plurality of cooling chambers (521) may be formed penetrating the main body (523) along the axis (C) parallel to the direction in which the recovery gas is transported. In addition, the sublimation cooling unit (520') according to the present embodiment does not have a branch line (46), but at least one of the plurality of cooling chambers (521) may be arranged to be connected to the recovery line (45) and the resupply line (50).

That is, the control unit controls some of the plurality of cooling chambers (521) to perform cooling, and by rotating the main body (523) around the axis (C), the cooling chamber (521) performing cooling can be controlled to communicate with the recovery line (45) and the resupply line (50).

More specifically, when the cooling chamber (521a) located on the upper side of FIG. 3 is cooled by a cooling means (not shown) while being connected to the recovery line (45) and the resupply line (50), when the recovery gas passes through the upper cooling chamber (521a), the water vapor is sublimated and frozen inside the cooling chamber, thereby being removed from the recovery gas. However, when the space inside the cooling chamber becomes narrow after the upper cooling chamber (521a) through which the recovery gas is transported has been cooled for a predetermined period of time, and the frozen ice needs to be removed, the control unit controls the lower cooling chamber (521b) to perform cooling, and then rotates the main body (523) around the axis (C) to change the cooling chamber (521) through which the recovery gas is transported to the lower cooling chamber (521b). In addition, by switching the cooling chamber (521a) through which the cooling operation has been performed for a predetermined period of time so that heating is performed, the ice sublimated by the cooling can be liquefied and removed.

In the sublimation cooling unit (520') according to the present embodiment, since the cooling chamber (521) to which the recovery gas is transferred can be changed simply by rotating the main body (523) around the axis (C), lithium sulfide can be continuously manufactured without stopping the lithium sulfide manufacturing device, which is efficient, and since hydrogen sulfide from which moisture has been more reliably removed can be re-supplied to the reaction chamber, high-purity lithium sulfide can be obtained, and the economic feasibility of the process is improved.

Fig. 4 is a front view showing a sublimation cooling unit according to another embodiment of the present invention. The sublimation cooling unit (520'') according to the present embodiment is different from the sublimation cooling unit (520') described above in that it has three or more cooling chambers (521). The number of cooling chambers (521) is not particularly limited.

For example, when four cooling chambers (521a, 521b, 521c, 521d) are formed penetrating the main body (523) as shown in FIG. 4, at least one cooling chamber may be provided to communicate with the recovery line (45) and the resupply line (50). In addition, the control unit may control the plurality of cooling chambers (521a, 521b, 521c, 521d) to be sequentially cooled and, by rotating the main body (523) around the axis (C), control the recovery gas to be transferred to the cooling chamber where cooling is in progress. Similarly, for the cooling chamber that has been cooled for a predetermined time, heating may be performed so that ice sublimated by cooling may be liquefied and removed.

Alternatively, the sublimation cooling unit (520'') according to the present embodiment may be controlled to perform cooling in a plurality of cooling chambers (521a, 521b), and in this case, a plurality of lines branched from the recovery line (45) may be provided to communicate with a plurality of cooling chambers (521a, 521b) that perform cooling, respectively. The number of cooling chambers (521) may be appropriately provided based on the amount of water vapor generated, such as the size of the reaction chamber (100), the temperature at which the heating unit (150) heats the reaction space, and the like.

In this way, the hydrogen sulfide gas discharged from the reaction chamber (100), recovered through the condensation unit (300) and the solvent resupply unit (400), and from which moisture is completely removed in the moisture removal unit (500), may be supplied back into the reaction chamber through the resupply line (50) to the bottom of the reaction chamber (100), the hydrogen sulfide supply unit (200), or the hydrogen sulfide supply line (20) (see FIG. 1). The resupply line (50) may be connected to one end of the bottom of the reaction chamber (100). In addition, the resupply line (50) may also be connected to one side of the hydrogen sulfide supply unit (200) or the hydrogen sulfide supply line (20). Meanwhile, the lithium raw material supplied into the reaction chamber (100) falls to the lower side of the reaction chamber (100) by gravity and reacts with the hydrogen sulfide supplied in the reaction solvent. At this time, the supplied hydrogen sulfide is supplied in a bubbled state into the reaction chamber by an in-line disperser or the like, so that the reaction area can be increased, and thus the reaction with the lithium raw material can be performed more smoothly.

The above description is merely an illustrative description of the technical idea of the present invention, and those skilled in the art will appreciate that various modifications and variations may be made without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

10: Lithium raw material supply line
20: Hydrogen sulfide supply line 30: Lithium sulfide recovery line
40: Exhaust line 45: Return line
46(46a, 46b): Branch line 47(47a, 47b): Branch valve
48(48a, 48b): Branch line 49(49a, 49b): Branch valve
50: Resupply line 60: Solvent resupply line
100: Reaction Chamber
150: Heating section
200: Hydrogen sulfide supply section 300: Condensation section
400: Solvent resupply section 500: Moisture removal section
515, 515': Exhaust
520, 520', 520'': Sublimation Cooling Unit
521(521a, 521b, 521c, 521d): Cooling chamber
523: Body
525: Cooling means
600: Lithium sulfide recovery unit
F: Absence of filter

Claims (12)

A reaction chamber having a reaction space for manufacturing lithium sulfide and provided with lithium raw materials;
A hydrogen sulfide supply unit provided to supply hydrogen sulfide to the above reaction chamber;
A heating unit provided to heat the above reaction space;
A lithium sulfide recovery unit provided to remove impurities from lithium sulfide generated by the reaction between hydrogen sulfide and lithium raw material within the above reaction chamber and to recover only pure lithium sulfide;
A condenser that recovers and condenses gas discharged from the reaction chamber;
A solvent resupply unit that receives a mixture from the condenser, selects a reaction solvent, and supplies it into the reaction chamber; and
A lithium sulfide mass production device, comprising: a moisture removal unit provided to remove water vapor from the recovery gas delivered from the solvent resupply unit and then supply only hydrogen sulfide gas to the bottom of the reaction chamber, a hydrogen sulfide supply unit, or a hydrogen sulfide supply line;
In claim 1,
A lithium sulfide mass production device, wherein a stirring member is further provided within the above reaction chamber to promote a reaction between the supplied hydrogen sulfide and lithium raw material.
In claim 1,
A lithium sulfide mass production device, wherein the above reaction chamber is made of at least one material selected from the group consisting of Hastelloy X, stainless steel 304 (SUS 304), stainless steel 310 (SUS 310), stainless steel 316 (SUS 316), alumina, quartz, and combinations thereof.
In claim 1,
A lithium sulfide mass production device, wherein the heating unit is mounted on the outer surface of the reaction chamber and heats the temperature of the reaction space to 120°C or higher and less than 300°C.
In claim 1,
A lithium sulfide mass production device, wherein the lithium raw material supplied to the above reaction chamber has a particle size of 1 mm or less.
In claim 1,
The above solvent resupply unit is a lithium sulfide mass production device, which is a Dean-Stark trap.
In claim 1,
The above moisture removal unit is a lithium sulfide mass production device, which is a sublimation cooling unit that cools the gas recovered from the solvent resupply unit and selectively removes only moisture from the gas.
In claim 7,
The above sublimation cooling unit includes a plurality of cooling chambers and a control unit for controlling the above sublimation cooling unit,
A lithium sulfide mass production device, wherein the control unit controls cooling so that, when the recovery gas is transferred to one or more preset cooling chambers among the plurality of cooling chambers, cooling is performed in the cooling chamber to which the recovery gas is transferred.
In claim 8,
The above control unit controls the cooling chamber to which the recovery gas is transferred so that after the cooling chamber to which the recovery gas is transferred is cooled for a predetermined period of time, the recovery gas is transferred to another cooling chamber, and causes heating to proceed with the cooling chamber that has been cooled for the predetermined period of time, thereby liquefying and removing ice sublimated by cooling. A lithium sulfide mass production device.
In claim 9,
The above sublimation cooling unit has a plurality of branch lines for transferring the recovery gas to each of the plurality of cooling chambers, and a valve installed in the branch lines to open and close each of the branch lines.
A lithium sulfide mass production device, wherein the control unit is configured to determine the cooling chamber to which the recovery gas is transferred by controlling the valve.
In claim 9,
The above sublimation cooling unit has a main body that is configured to rotate around an axis parallel to the direction in which the recovery gas is transported.
The above plurality of cooling chambers are formed through the main body in a direction parallel to the axis, and at least one of them is provided to communicate with a recovery line through which the recovery gas is transported and a resupply line through which the recovery gas is resupplied to the reaction chamber.
A lithium sulfide mass production device in which the control unit controls the cooling chamber, which is performing cooling, to be connected to the recovery line and the resupply line by rotating the main body around the axis.
In claim 11,
The above control unit controls the recovery line to be connected to another cooling chamber scheduled for cooling operation by rotating the main body around the axis after the cooling chamber into which the recovery gas is transferred has been cooled for a predetermined period of time, and causes heating to proceed with the cooling chamber that has been cooled for the predetermined period of time, thereby liquefying and removing ice sublimated by cooling. A lithium sulfide mass production device.