Lithium sulfide production apparatus and method for producing lithium sulfide

Abstract

To provide a device for producing lithium sulfide with high efficiency and stability.SOLUTION: A lithium sulfide production device 1 of the present invention comprises a reactor 3 having a lithium hydroxide filling part 2 inside, a jacket heater 4 that is heating means for heating the lithium hydroxide, and a hydrogen sulfide supply pipe 5 that is a hydrogen sulfide supply member connected to the reactor 3. Inside the reactor 3, a heat insulating member 6 is provided above the lithium hydroxide filling part 2, and at a part of the heat insulating member 6 or around the heat insulating member 6, the upper space and the lower space of the heat insulating member 6 are in communication.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a lithium sulfide production apparatus and a lithium sulfide production method. [Background technology]

[0002] A known method for producing lithium sulfide involves reacting hydrogen sulfide gas with lithium hydroxide. An example of such a lithium sulfide production method is described in Patent Document 1 (Japanese Patent Application Publication No. 2016-150860). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-150860 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the lithium sulfide manufacturing technologies described in Patent Document 1 and others have made it difficult to achieve sufficiently high manufacturing efficiency. Furthermore, there was room for improvement in the stability of manufacturing efficiency.

[0005] This invention has been made in view of the above circumstances, and provides a lithium sulfide production apparatus that can produce lithium sulfide stably with high efficiency. [Means for solving the problem]

[0006] The inventors of the present invention conducted various studies to determine why the lithium sulfide production efficiency of conventional lithium sulfide production equipment was insufficient. As a result, they discovered that lithium sulfide can be produced stably and with high efficiency by precisely controlling the temperature distribution in the lithium hydroxide-filled section, which is the site of the lithium sulfide production reaction. The present invention is based on this discovery.

[0007] According to the present invention, A lithium sulfide production apparatus for producing lithium sulfide by reacting hydrogen sulfide with lithium hydroxide, A reactor having a lithium hydroxide-filled section inside, A heating means for heating lithium hydroxide, A hydrogen sulfide supply member connected to the above reactor, Equipped with, Inside the reactor, a heat insulating member is provided above the lithium hydroxide-filled section. A lithium sulfide production apparatus is provided, wherein the upper space and lower space of the thermal insulation member are in communication with a part of the thermal insulation member or around the thermal insulation member.

[0008] Furthermore, the present invention provides a method for producing lithium sulfide, characterized by reacting hydrogen sulfide gas with lithium hydroxide using the lithium sulfide production apparatus described above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a lithium sulfide production apparatus with excellent manufacturing efficiency. [Brief explanation of the drawing]

[0010] [Figure 1] This is a longitudinal cross-sectional view of an example of a lithium sulfide production apparatus according to this embodiment. [Figure 2] This is a top view of the heat insulating member of the lithium sulfide production apparatus according to this embodiment. [Figure 3] This is a top view of the lithium hydroxide support member of the lithium sulfide production apparatus according to this embodiment. [Figure 4] This is a longitudinal cross-sectional view of another example of the lithium sulfide production apparatus of this embodiment. [Figure 5] This is a longitudinal cross-sectional view of the lithium sulfide production apparatus of Example 1. [Figure 6] This is a longitudinal cross-sectional view of the lithium sulfide production apparatus of Example 2. [Figure 7] This is a longitudinal cross-sectional view of the lithium sulfide production apparatus of Comparative Example 1. [Figure 8] It is a longitudinal sectional view of a lithium sulfide production apparatus of Comparative Example 2. [Figure 9] It is a graph showing the temperature of the reactor of the lithium sulfide production apparatuses of Examples 1 to 2 and Comparative Examples 1 to 2.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by common reference numerals, and the description thereof will be omitted as appropriate.

[0012] [First Embodiment] An example of the lithium sulfide production apparatus of the present embodiment will be described with reference to FIGS. 1 to 3.

[0013] FIG. 1 is a longitudinal sectional view of the lithium sulfide production apparatus 1. FIG. 2 is a top view of the heat insulating member 6 provided in the lithium sulfide production apparatus 1. FIG. 3 is a top view of the lithium hydroxide support member 7 provided in the lithium sulfide production apparatus 1.

[0014] The lithium sulfide production apparatus 1 includes a reactor 3 having a lithium hydroxide filling portion 2 inside, a jacket heater 4 which is a heating means for heating lithium hydroxide, and a hydrogen sulfide supply pipe 5 which is a hydrogen sulfide supply member connected to the reactor 3. Inside the reactor 3, a heat insulating member 6 is provided above the lithium hydroxide filling portion 2, and in a part of the heat insulating member 6 or around the heat insulating member 6, the upper space and the lower space of the heat insulating member 6 communicate with each other.

[0015] In the lithium sulfide production apparatus 1 of the present embodiment, since the heat insulating member 6 is provided above the reactor 3, heat dissipation to the outside of the reactor 3 is prevented, and the temperature of the entire lithium hydroxide filling portion 2 is maintained high and uniform. For this reason, the reaction field between hydrogen sulfide gas and lithium hydroxide is controlled with high precision at a high temperature, and lithium sulfide can be stably produced with high production efficiency.

[0016] The configuration of each part of the lithium sulfide production apparatus of this embodiment will be described below.

[0017] (Reactor 3) Inside reactor 3, lithium sulfide (solid) is produced by the reaction of lithium hydroxide (solid) with hydrogen sulfide gas.

[0018] A hydrogen sulfide supply pipe 5 is connected to reactor 3, and hydrogen sulfide is supplied from the hydrogen sulfide supply pipe 5.

[0019] Furthermore, the reactor 3 is equipped with a lithium hydroxide support member 7, and the space enclosed by the lithium hydroxide support member 7, the heat insulating member 6, and the inner wall of the reactor 3 is called the lithium hydroxide filled section 2.

[0020] Lithium hydroxide (not shown) is placed on the lithium hydroxide support member 7.

[0021] The hydrogen sulfide supply pipe 5 is preferably located below the lithium hydroxide support member 7. By supplying hydrogen sulfide gas to the lithium hydroxide support member 7 from below, it is vented upwards towards the reactor 3 and comes into contact with the lithium hydroxide packed in the lithium hydroxide packing section 2, allowing water (water vapor), a by-product with a lower specific gravity than hydrogen sulfide gas, to be efficiently discharged. Furthermore, by continuously venting hydrogen sulfide gas upwards towards the reactor 3, a constant supply of fresh hydrogen sulfide gas is ensured.

[0022] It is preferable that the lithium hydroxide support member 7 is provided with a plurality of communication holes 171, as shown in Figure 3. This is because the hydrogen sulfide gas supplied from the hydrogen sulfide supply pipe 5 is efficiently supplied to the lithium hydroxide filling section 2 through the communication holes 171.

[0023] The hydrogen sulfide gas supplied from the hydrogen sulfide supply pipe 5 comes into contact with the surface of the lithium hydroxide (solid) filled in the lithium hydroxide filling section 2.

[0024] It is thought that the reaction shown in equation (1) below is occurring on the surface of lithium hydroxide (solid). 2LiOH + H2S → Li2S + 2H2O (1)

[0025] In the lithium hydroxide-filled section 2 inside the reactor 3, it is preferable that the lithium hydroxide is packed in layers, and that the layered lithium hydroxide is in contact with the inner wall surface of the reactor 3. This is because heating can be achieved by heat transfer from the inner wall surface of the lithium hydroxide-filled section 2, thereby increasing the heating efficiency.

[0026] The temperature of the lithium hydroxide-filled section 2 is typically adjusted to 100-445°C, preferably 130-410°C, from the viewpoint of promoting the above reaction and preventing the melting of lithium hydroxide. The temperature of the lithium hydroxide-filled section 2 is usually measured at the horizontal center of the lithium hydroxide-filled section 2.

[0027] It is preferable that the heat insulating member 6 is provided with a plurality of communication holes 161, as shown in Figure 2. This is because the heat insulating member is provided with a plurality of communication holes 161 so that unreacted hydrogen sulfide gas and exhaust gas containing water produced by the reaction of hydrogen sulfide gas with lithium hydroxide can be discharged to the outside of the reactor 3 through the communication holes 171.

[0028] The material of reactor 3 can be metal or ceramic, but it is preferable that it be a sulfur-resistant material. Examples of sulfur-resistant materials include metal-based sulfur-resistant materials such as stainless steel and aluminum, and ceramic-based sulfur-resistant materials such as quartz, boron nitride, aluminum nitride, and silicon nitride.

[0029] It is preferable that the inner surface of reactor 3 is treated to resist sulfurization.

[0030] As a means of sulfur-resistant treatment, plating treatments using metals or alloys with high sulfurization resistance can be mentioned, such as tin plating, chromium plating, gold plating, hot-dip aluminum plating, or alloy plating containing these metals.

[0031] Furthermore, metal diffusion permeation treatment may be used as a means of sulfur-resistant treatment. It is known that when a metal diffusion permeation layer is formed on the surface of the workpiece by applying metal diffusion permeation treatment, the sulfurization resistance performance is improved. For example, a calorizing treatment that diffuses and permeates aluminum can be used. In the calorizing treatment, the workpiece is embedded in a steel case with a mixture of Fe-Al alloy powder and NH4Cl powder, the case is sealed, and it is heated in a furnace. This forms an aluminum diffusion permeate layer on the surface of the workpiece, thereby improving the sulfurization resistance of the workpiece.

[0032] (Jacket heater 4) In this embodiment, a jacket heater 4 is used as a heating means for heating lithium hydroxide.

[0033] In other words, the jacket heater 4 heats the lithium hydroxide support member 7 and the space above the lithium hydroxide support member 7. This heats the lithium hydroxide filled in the lithium hydroxide filling section 2, thereby promoting the lithium sulfide production reaction.

[0034] The temperature of the jacket heater 4 is configured to adjust the temperature of the lithium hydroxide-filled section 2 to the above-mentioned temperature range. The required heating temperature varies depending on the diameter of the lithium hydroxide-filled section 2 and the amount of catalyst filled, so the temperature range of the jacket heater 4 is not particularly limited, but is preferably 100 to 445°C, and more preferably 130 to 410°C.

[0035] Furthermore, although a jacket heater 4 was used as the heating means in this embodiment, the invention is not limited to this, and any heating means capable of heating lithium hydroxide may be used. For example, a method of introducing heated hydrogen sulfide gas, a high-frequency induction heating device, etc., can also be used.

[0036] (Hydrogen sulfide supply pipe 5) The hydrogen sulfide supply pipe 5 is a component for supplying hydrogen sulfide gas to the reactor 3.

[0037] The hydrogen sulfide supply pipe 5 is preferably located below the lithium hydroxide support member 7. By supplying hydrogen sulfide gas to the lithium hydroxide support member 7 from below, it is vented upwards towards the reactor 3 and comes into contact with the lithium hydroxide packed in the lithium hydroxide packing section 2, allowing water (water vapor), a by-product with a lower specific gravity than hydrogen sulfide gas, to be efficiently discharged. Furthermore, by continuously venting hydrogen sulfide gas upwards towards the reactor 3, a constant supply of fresh hydrogen sulfide gas is ensured.

[0038] The hydrogen sulfide supply pipe 5 may have a hydrogen sulfide supply control valve 8 for adjusting the amount of hydrogen sulfide gas supplied, as shown in Figure 1. By adjusting the opening and closing of the hydrogen sulfide supply control valve 8, it is possible to control the amount of hydrogen sulfide supplied, which is preferable from the viewpoint of controlling the lithium sulfide production reaction carried out in the reactor 3.

[0039] The material used for the hydrogen sulfide supply pipe 5 can be the same material used for the reactor 3 as described above.

[0040] It is preferable that the inner surface of the hydrogen sulfide supply pipe 5 is treated to resist sulfurization. As a means of sulfurization treatment, the method described above can be used as a method for treating the inner surface of the reactor 3 to resist sulfurization.

[0041] Furthermore, although a hydrogen sulfide supply pipe 5 was used as the hydrogen sulfide supply member in this embodiment, the invention is not limited to this, and any hydrogen sulfide supply member that is capable of supplying hydrogen sulfide gas to the reactor 3 may be used.

[0042] (Insulation material 6) The insulating member 6 is a member for insulating the inside of the reactor 3 and is provided above the lithium hydroxide filled section 2.

[0043] As shown in Figure 1, it is preferable that the heat insulating member 6 is located above the lithium hydroxide-filled section 2 and covers the entire lithium hydroxide-filled section 2. This further prevents heat from being released to the outside of the reactor 3.

[0044] Furthermore, it is preferable that the side surface of the heat insulating member 6 is in contact with the inner wall of the reactor 3, as shown in Figure 1. By doing so, the heat insulating member 6 is also heated, and since the heat insulating member 6 itself has a certain heat capacity, the heat retention effect of the heat insulating member 6 is further enhanced.

[0045] It is preferable that the heat insulating member 6 is provided with a plurality of communication holes 161, as shown in Figure 2. This is because the heat insulating member is provided with a plurality of communication holes 161 so that unreacted hydrogen sulfide gas and exhaust gas containing water produced by the reaction of hydrogen sulfide gas with lithium hydroxide can be discharged to the outside of the reactor 3 through the communication holes 161.

[0046] Furthermore, the heat insulating member 6 may be provided with a through-hole 162 for a temperature sensor, as shown in Figure 2. In this case, the temperature sensor 9 inserted from above the reactor 3 passes through the through-hole 162 for the temperature sensor and is connected to the reactor 3.

[0047] The material used for the insulating material 6 is the same as the material used for the reactor 3, as described above.

[0048] The shape of the heat insulating member 6 is not particularly limited, but as described above, it is preferable that it is provided with a plurality of communication holes 161. For example, one or more types of porous materials selected from metal mesh such as stainless steel mesh or aluminum mesh; perforated metal such as stainless steel punching or aluminum punching; expanded metal such as stainless steel expanded or aluminum expanded can be used.

[0049] If necessary, two or more of the porous material described above may be used as the thermal insulation material 6.

[0050] The area ratio of the communication holes 161 provided in the heat insulating member 6 is usually 0.2% to 50%, and preferably 0.5% to 40%, from the viewpoint of balancing improved heat insulating efficiency and improved recovery of exhaust gases, etc.

[0051] The diameter of the communication holes 161 provided in the heat insulating member 6 is usually 26 μm to 10,000 μm, and preferably 45 μm to 5,000 μm, from the viewpoint of balancing improved heat insulating efficiency and improved recovery of exhaust gases, etc.

[0052] From the viewpoint of improving thermal insulation efficiency, the thickness of the thermal insulation material 6 is preferably 0.5 mm or more, and more preferably 1.5 mm or more. There is no particular upper limit to the thickness of the thermal insulation material 6, but it is usually 20 mm or less.

[0053] As for the shape of the heat insulating member, an inverted funnel-shaped heat insulating member 46 as shown in Figure 6 may be used. When an inverted funnel-shaped insulating member 46 is used as the insulating member, the temperature sensor 9 can be inserted into the leg portion of the inverted funnel-shaped insulating member 46 and connected to the lithium hydroxide-filled portion 2. In this case, a gap is formed between the temperature sensor 9 and the inner wall of the leg portion of the inverted funnel-shaped insulating member 46, allowing the upper and lower spaces of the inverted funnel-shaped insulating member 46 to communicate through this gap.

[0054] (Lithium hydroxide support member 7) The lithium hydroxide support member 7 is a member for supporting lithium hydroxide.

[0055] As described above, in order to enable heating by heat transfer from the inner wall surface of the reactor 3, it is preferable that the lithium hydroxide is packed in layers so as to be in contact with the inner wall of the lithium hydroxide packed section 2. Therefore, it is preferable that the lithium hydroxide support member 7 be positioned so as to be in contact with the inner wall of the lithium hydroxide packed section 2 so that the lithium hydroxide can be placed on it in this manner.

[0056] It is preferable that the lithium hydroxide support member 7 is provided with a plurality of communication holes 171, as shown in Figure 3. This is because the provision of a plurality of communication holes 171 in the lithium hydroxide support member 7 allows hydrogen sulfide supplied from the hydrogen sulfide supply pipe 5 to be efficiently supplied to the lithium hydroxide filling section 2 through the plurality of communication holes 171.

[0057] The material used for the lithium hydroxide support member 7 can be the same as the material used for the reactor 3, as described above.

[0058] The shape of the lithium hydroxide support member 7 is not particularly limited as long as lithium hydroxide can be placed on it, but as described above, it is preferable that it is provided with a plurality of communication holes 171. For example, one or more porous materials selected from metal mesh such as stainless steel mesh or aluminum mesh; perforated metal such as stainless steel punching or aluminum punching; expanded metal such as stainless steel expanded, etc. can be used.

[0059] If necessary, two or more of the above-mentioned porous material may be used as the lithium hydroxide support member 7 by stacking them together.

[0060] The diameter of the communication hole 171 provided in the lithium hydroxide support member 7 depends on the diameter of the lithium hydroxide placed on it, but is usually 26 μm to 300 μm, and preferably 45 μm to 154 μm.

[0061] (Gas discharge pipe 10) The gas discharge pipe 10 is a component for discharging exhaust gas containing unreacted hydrogen sulfide and water produced by the reaction of hydrogen sulfide gas with lithium hydroxide to the outside of the reactor 3.

[0062] The gas discharge pipe 10 is preferably located above the lithium hydroxide support member 7. This is because the by-product water (water vapor) and unreacted hydrogen sulfide gas are passed upwards through the reactor, and therefore, having the gas discharge pipe 10 located above improves the efficiency of gas discharge. Improved gas discharge efficiency ensures a constant supply of fresh hydrogen sulfide gas.

[0063] It is preferable that the gas discharge pipe 10 be equipped with a cooling section to capture the water produced by the reaction between hydrogen sulfide gas and lithium hydroxide. Once the reaction between hydrogen sulfide gas and lithium hydroxide is complete, the water generated during the production of lithium sulfide will no longer condense in the cooling section. In other words, the progress of the lithium sulfide production reaction can be monitored by the amount of water that condenses.

[0064] (Temperature sensor 9) The temperature sensor 9 is a component used to measure the temperature inside the reactor 3. For example, by measuring the temperature inside the reactor 3 with the temperature sensor 9 and adjusting the heating based on the measurement results, it becomes possible to control the production of lithium sulfide with greater precision.

[0065] [Second Embodiment] The lithium sulfide production apparatus of this embodiment may further include a heat transfer member 22 arranged in contact with or near the bottom surface of the lithium hydroxide filling section 2. Figure 4 is a longitudinal cross-sectional view of the lithium sulfide production apparatus 21 as described above. By providing a heat transfer member 22 at the bottom of the lithium hydroxide filling section 2, heat from the jacket heater 4 covering the outside of the reactor 3 is more easily transferred to the lithium hydroxide filling section 2 in the horizontal direction of its cross-section, thereby improving the uniformity of heat distribution in the horizontal direction of the lithium hydroxide filling section 2.

[0066] It is preferable that the heat transfer member 22 is positioned in contact with the inner wall of the lithium hydroxide-filled section. This is to more efficiently transfer heat from the jacket heater 4 that covers the outside of the reactor 3.

[0067] It is preferable that the heat transfer member 22 is provided with multiple communication holes. This is because the multiple communication holes in the heat transfer member allow hydrogen sulfide supplied from the hydrogen sulfide supply pipe 5 to be efficiently supplied to the lithium hydroxide filling section 2 through the multiple communication holes.

[0068] The material of the heat transfer member 22 is not particularly limited, and the materials described above can be used as the material of the reactor 3. However, it is preferable to use a material with excellent sulfidation resistance and thermal conductivity, such as aluminum, aluminum alloy, aluminum nitride, or silicon nitride.

[0069] Furthermore, the shape of the heat transfer member 22 is not particularly limited, but it is preferable that it has multiple connecting holes, such as perforated metal. For example, one or more porous materials selected from metal mesh such as stainless steel mesh or aluminum mesh; perforated metal such as stainless steel punching or aluminum punching; expanded metal such as stainless steel expanded or aluminum expanded can be used.

[0070] If necessary, two or more of the porous material described above may be used as the heat transfer member 22.

[0071] The area ratio of the communication holes provided in the heat transfer member 22 is usually 0.2% to 50%, and preferably 0.5% to 40%, from the viewpoint of balancing improved heat transfer efficiency and improved contact efficiency between sulfur vapor and the catalyst.

[0072] The diameter of the communication holes provided in the heat transfer member 22 is usually 26 μm to 10,000 μm, and preferably 45 μm to 5,000 μm.

[0073] [Differentiation] The lithium sulfide production apparatus of this embodiment may include components other than those described above.

[0074] Furthermore, the lithium sulfide production apparatus of this embodiment may have its parts formed integrally.

[0075] [Lithium sulfide manufacturing process] The lithium sulfide production process using the lithium sulfide production apparatus 1 of this embodiment will be described.

[0076] First, lithium hydroxide is filled into the lithium hydroxide filling section 2, and the lithium hydroxide filling section 2 filled with lithium hydroxide is heated by a jacket heater 4, which is a heating means. Next, hydrogen sulfide gas is supplied to the lithium hydroxide filling section 2, and the hydrogen sulfide gas is brought into contact with the lithium hydroxide, generating lithium sulfide through the reaction between lithium hydroxide and hydrogen sulfide gas.

[0077] Since an insulating member 6 is provided above the reactor 3 of the lithium sulfide production apparatus 1, heat is prevented from being released to the outside of the reactor 3, and the temperature of the entire lithium hydroxide filling section 2 is maintained at a high and uniform level. Therefore, lithium sulfide can be produced stably with high efficiency in the lithium sulfide production apparatus 1.

[0078] In the lithium sulfide production process using the lithium sulfide production apparatus 1, the temperature inside the lithium hydroxide filling section 2 is typically 100°C or higher, preferably 130°C or higher, more preferably 150°C or higher, more preferably 170°C or higher, and more preferably 200°C or higher throughout the entire range. If the temperature inside the lithium hydroxide-filled section 2 is above the lower limit value throughout the entire range, the reaction rate between hydrogen sulfide gas and lithium hydroxide can be further improved.

[0079] In the lithium sulfide production process using the lithium sulfide production apparatus 1, the temperature of the lithium hydroxide packing section 2 is preferably 445°C or lower, more preferably 430°C or lower, and even more preferably 410°C or lower throughout the entire range. When the temperature of the catalyst packing section is below the above upper limit throughout the entire range, the melting of lithium hydroxide can be suppressed, thereby preventing the lithium hydroxide from fusing together and forming lumps. This allows the reaction between the reaction gas and lithium hydroxide to proceed more effectively.

[0080] In the lithium sulfide production process using the lithium sulfide production apparatus 1, the highest temperature T measured at each point in the lithium hydroxide filling section 2 is max and the lowest temperature T min The difference (T max -T min The temperature is preferably 50°C or lower, more preferably 30°C or lower, even more preferably 20°C or lower, and preferably as small as possible. max -T min When the temperature variation is small, that is, when the temperature variation at each point in the lithium hydroxide filling section 2 is small, the reaction between hydrogen sulfide gas and lithium hydroxide can proceed more efficiently and stably.

[0081] In the weight-based particle size distribution of lithium hydroxide measured by laser diffraction scattering, d50 is preferably 1.5 mm or less, and more preferably 1.0 mm or less. When d50 is below the above upper limit, the contact area between lithium hydroxide and the reaction gas increases, promoting the reaction, and thus reducing the amount of unreacted raw materials in the resulting lithium sulfide. As a result, higher purity lithium sulfide can be obtained. Furthermore, the d50 in the weight-based particle size distribution of lithium hydroxide measured by laser diffraction scattering particle size distribution measurement is preferably 0.1 mm or more, and more preferably 0.2 mm or more. When d50 is above the above lower limit, water generated in the reaction system can adhere to the lithium sulfide particles, preventing the particles from sticking together. It is also possible to suppress the discharge of lithium hydroxide and the obtained lithium sulfide along with the reaction gas, thus simplifying exhaust gas treatment. In addition, it is possible to suppress the scattering of lithium hydroxide and the obtained lithium sulfide by the reaction gas, thereby improving the yield of lithium sulfide.

[0082] It is preferable to dehydrate the lithium hydroxide beforehand by removing the crystal water and drying any adhering water. This suppresses the agglomeration of lithium hydroxide and inhibits the formation of water sulfides, thereby allowing the reaction between hydrogen sulfide gas and lithium hydroxide to proceed more effectively. Methods for dehydrating and drying lithium hydroxide include, for example, heating in the atmosphere, heating while flowing a gas such as hydrogen, nitrogen, or argon gas, or heating under reduced pressure.

[0083] The hydrogen sulfide gas may be a commercially available product filled in a gas cylinder or the like, or it may be produced in a hydrogen sulfide production device connected upstream of the lithium sulfide production device 1. If a hydrogen sulfide production device is connected upstream of the lithium sulfide production device 1, it is possible to generate only the amount of hydrogen sulfide gas necessary for lithium sulfide production, eliminating the need to store hydrogen sulfide gas separately. Furthermore, since hydrogen sulfide gas can be generated as needed, high-purity hydrogen sulfide gas that has not deteriorated over time can be used in the reaction.

[0084] The lithium sulfide obtained by the manufacturing process using the lithium sulfide manufacturing apparatus 1 can be suitably used, for example, as a positive electrode active material, a negative electrode active material, a solid electrolyte material for batteries, or as an intermediate raw material for chemicals.

[0085] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. [Examples]

[0086] (Example 1) A lithium sulfide production apparatus 31 was fabricated using the following components. Figure 5 is a longitudinal cross-sectional view of the production apparatus 31. • Reactor 3: A reaction tube made of SUS316L with the inner wall of the bottom 450mm treated with aluminum calorizing (inner diameter 124mm, height 615mm). • Insulation material 36: One sheet of perforated aluminum metal (diameter 116 mm, thickness 0.5 mm, hole diameter 0.5 mm, area ratio of hole diameter 27.9%) is placed on top of two aluminum plates (diameter 116 mm, thickness 0.5 mm, hole diameter 5 mm, area ratio of hole diameter 1.7%), with an 8 mm gap between them. • Lithium hydroxide support member 37: A #100 aluminum mesh is layered on top of a #300 stainless steel mesh. • Heat transfer element 22: Aluminum plate (diameter 123 mm, thickness 20 mm, hole diameter 5 mm, hole diameter area ratio 9.7%)

[0087] A heat transfer member 22 was placed in reactor 3, and a lithium hydroxide support member 37 was placed on top of the heat transfer member 22. 773g of lithium hydroxide (particle size 0.05~0.75mm) was packed onto the lithium hydroxide support member 37. The height of the packed lithium hydroxide was 100mm. Next, the heat transfer member 22 was placed on top of the lithium hydroxide.

[0088] The temperature sensor 9, inserted through a through-hole for the temperature sensor provided in the heat insulating member 36, reaches the bottom surface of the lithium hydroxide filling section 2, i.e., the lithium hydroxide support member 37, enabling the temperature sensor 9 to measure the temperature at each vertical point in the horizontal center of the lithium hydroxide filling section 2.

[0089] Next, a mixture of hydrogen and hydrogen sulfide gas (hydrogen sulfide concentration 13%) was supplied to reactor 3 via hydrogen sulfide supply pipe 5 at a flow rate of 2.0 L / min. Then, the temperature of jacket heater 4 was raised to 410°C to heat lithium hydroxide filling section 2. This caused the hydrogen sulfide gas to react with lithium hydroxide to obtain lithium sulfide.

[0090] (Example 2) A lithium sulfide production apparatus 41 was manufactured in the same manner as in Example 1, except that an inverted funnel-shaped heat insulating member 46 was used instead of the heat insulating member 36 as a heat insulating member, and the temperature sensor 9 was inserted into the leg of the inverted funnel-shaped heat insulating member 46 and brought to the lithium hydroxide support member 37, and lithium sulfide was produced. Furthermore, a gap is formed between the temperature sensor 9 and the inner wall of the leg portion of the inverted funnel-shaped heat insulating member 46, and this gap allows the upper and lower spaces of the inverted funnel-shaped heat insulating member 46 to communicate with each other. Figure 6 is a longitudinal cross-sectional view of the manufacturing apparatus 41.

[0091] (Comparative Example 1) A lithium sulfide production apparatus 51 was manufactured in the same manner as in Example 1, except that the heat insulating member 36 and the heat transferring member 22 were omitted, and a #300 stainless steel mesh was placed on top of a SUS perforated metal with a diameter of 123 mm, a thickness of 0.5 mm, and a hole diameter of 0.5 mm, and then a #100 aluminum mesh was placed on top of that as the lithium hydroxide support member 57, and lithium sulfide was produced. Figure 7 is a longitudinal cross-sectional view of the manufacturing apparatus 51.

[0092] (Comparative Example 2) A lithium sulfide production apparatus 61 was manufactured in the same manner as in Example 1, except that the heat insulating member 36 was omitted, and lithium sulfide was produced. Figure 8 is a longitudinal cross-sectional view of the manufacturing apparatus 61.

[0093] Figure 9 shows a graph of the temperature at each point in the lithium hydroxide filling section 2 measured by the temperature sensor 9 150 minutes after the start of heating in the lithium sulfide production apparatus of Examples 1-2 and Comparative Examples 1-2.

[0094] According to FIG. 9, in the lithium sulfide production apparatuses of Examples 1 and 2, a high temperature is maintained even at the upper part of the lithium hydroxide filling section 2, and lithium sulfide can be stably produced with high efficiency, which is considered to be due to the reaction field between hydrogen sulfide gas and lithium hydroxide being precisely controlled at a high temperature.

[0095] The maximum temperature T of the temperature measured at each point of the lithium hydroxide filling section 2 max , the minimum temperature T min , and the difference between the two (T max -T min ) are shown in Table 1.

[0096]

Table 1

[0097] According to Table 1, in the lithium sulfide production apparatuses of Examples 1 and 2, the value of T max -T min was small. That is, in the lithium sulfide production apparatuses of Examples 1 and 2, since the variation in the temperature at each point of the lithium hydroxide filling section 2 is small, lithium sulfide can be stably produced with high efficiency, which is considered to be due to the reaction field between hydrogen sulfide gas and lithium hydroxide being precisely controlled at a high temperature.

Explanation of Reference Numerals

[0098] 1 Lithium sulfide production apparatus 2 Lithium hydroxide filling section 3 Reactor 4 Jacket heater 5 Hydrogen sulfide supply pipe 6 Heat insulating member 7 Lithium hydroxide support member [[ID=​​​​​​​​​​​​ 37 Lithium hydroxide support member 41. Lithium sulfide production equipment 46. ​​Insulation material 51 Lithium sulfide production equipment 57 Lithium hydroxide support member 61 Lithium sulfide production equipment 161 Communication hole 162 Through-hole for temperature sensor

Claims

1. A lithium sulfide production apparatus for producing lithium sulfide by reacting hydrogen sulfide with lithium hydroxide, The reactor is equipped with a lithium hydroxide-filled section inside, A lithium sulfide production apparatus, wherein a heat insulating member is provided inside the reactor above the lithium hydroxide-filled section.

2. A lithium sulfide production apparatus according to Claim 1, A lithium sulfide production apparatus further comprising a heating means for heating lithium hydroxide.

3. A lithium sulfide production apparatus according to claim 1 or 2, A lithium sulfide production apparatus further comprising a hydrogen sulfide supply member connected to the reactor.

4. A lithium sulfide production apparatus according to any one of claims 1 to 3, A lithium sulfide production apparatus in which the upper space and lower space of the insulating member are in communication with a part of the insulating member or around the insulating member.

5. A lithium sulfide production apparatus according to any one of claims 1 to 4, A lithium sulfide production apparatus further comprising a heat transfer member positioned in contact with or near the bottom surface of the lithium hydroxide-filled section.

6. A lithium sulfide production apparatus according to any one of claims 1 to 5, A lithium sulfide production apparatus in which the inner surface of the lithium sulfide production apparatus is treated to prevent sulfurization.

7. A method for producing lithium sulfide, characterized by reacting hydrogen sulfide gas with lithium hydroxide using a lithium sulfide production apparatus described in any one of claims 1 to 6.

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