Device for producing lithium sulfide 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] The present invention relates to an apparatus for producing lithium sulfide and a method for producing lithium sulfide. [Background technology]

[0002] A known method for producing lithium sulfide is to react hydrogen sulfide gas with lithium hydroxide. Examples of techniques related to such lithium sulfide production methods include the one described in Patent Document 1 (JP 2016-150860 A). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-150860 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it has been difficult to achieve sufficiently high production efficiency with the lithium sulfide production techniques disclosed in Patent Document 1 and the like, and there is also room for improvement in the stability of production efficiency.

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

[0006] The present inventors have conducted various studies to find out why the lithium sulfide production efficiency of conventional lithium sulfide production apparatuses was insufficient. As a result, they have found 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 finding.

[0007] According to the present invention, An apparatus for producing lithium sulfide by reacting hydrogen sulfide with lithium hydroxide, a reactor having a lithium hydroxide-filled portion therein; a heating means for heating the lithium hydroxide; a hydrogen sulfide supply member connected to the reactor; Equipped with a heat insulating member is provided inside the reactor above the lithium hydroxide-filled section, In the apparatus for manufacturing lithium sulfide, an upper space and a lower space of the heat insulating member are in communication with each other at a part of the heat insulating member or around the heat insulating member.

[0008] Furthermore, according to the present invention, there is provided a method for producing lithium sulfide, which comprises reacting hydrogen sulfide gas with lithium hydroxide using the above-described apparatus for producing lithium sulfide. [Effects of the Invention]

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

[0010] [Figure 1] FIG. 1 is a longitudinal sectional view of an example of an apparatus for manufacturing lithium sulfide according to an embodiment of the present invention. [Figure 2] FIG. 2 is a top view of a heat insulating member of the apparatus for manufacturing lithium sulfide according to the present embodiment. [Figure 3] FIG. 2 is a top view of a lithium hydroxide support member of the apparatus for manufacturing lithium sulfide according to the present embodiment. [Figure 4] FIG. 2 is a vertical cross-sectional view of another example of the apparatus for manufacturing lithium sulfide according to the present embodiment. [Figure 5] FIG. 1 is a vertical cross-sectional view of an apparatus for manufacturing lithium sulfide according to a first embodiment. [Figure 6] FIG. 1 is a vertical cross-sectional view of an apparatus for manufacturing lithium sulfide according to a second embodiment. [Figure 7] FIG. 2 is a longitudinal sectional view of an apparatus for producing lithium sulfide according to Comparative Example 1. [Figure 8] FIG. 1 is a longitudinal sectional view of an apparatus for manufacturing lithium sulfide according to Comparative Example 2. [Figure 9] 1 is a graph showing the temperatures of reactors of the lithium sulfide manufacturing apparatuses of Examples 1 and 2 and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

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

[0012] [First embodiment] An example of an apparatus for producing lithium sulfide according to this embodiment will be described with reference to FIGS. 1 to 3.

[0013] Fig. 1 is a vertical cross-sectional view of an apparatus for manufacturing lithium sulfide 1. Fig. 2 is a top view of a heat insulating member 6 provided in the apparatus for manufacturing lithium sulfide 1. Fig. 3 is a top view of a lithium hydroxide support member 7 provided in the apparatus for manufacturing lithium sulfide 1.

[0014] The lithium sulfide manufacturing apparatus 1 includes a reactor 3 having a lithium hydroxide-filled section 2 therein, a jacket heater 4 serving as a heating means for heating the lithium hydroxide, and a hydrogen sulfide supply pipe 5 serving as 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 filled section 2, and the upper space and lower space of the heat insulating member 6 are in communication with each other at a part of the heat insulating member 6 or around the heat insulating member 6.

[0015] In the apparatus for manufacturing lithium sulfide 1 of the present embodiment, a heat insulating member 6 is provided above the reactor 3, thereby preventing heat from being released to the outside of the reactor 3 and maintaining a high and uniform temperature throughout the lithium hydroxide-filled section 2. As a result, the reaction field between hydrogen sulfide gas and lithium hydroxide is controlled at a high temperature with high precision, enabling stable production of lithium sulfide with high production efficiency.

[0016] The configuration of each part of the apparatus for manufacturing lithium sulfide according to this embodiment will be described below.

[0017] (Reactor 3) Inside the reactor 3, lithium hydroxide (solid) reacts with hydrogen sulfide gas to produce lithium sulfide (solid).

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

[0019] The reactor 3 is also provided with a lithium hydroxide support member 7, and the space surrounded by the lithium hydroxide support member 7, the heat insulating member 6, and the inner wall of the reactor 3 is called a 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 positioned below the lithium hydroxide support member 7. This is because hydrogen sulfide gas is supplied to the lithium hydroxide support member 7 from below, and thereby passes upward in the reactor 3, where it comes into contact with the lithium hydroxide filled in the lithium hydroxide filled section 2, thereby efficiently discharging water (water vapor), a by-product with a smaller specific gravity than hydrogen sulfide gas. Furthermore, by continuously passing hydrogen sulfide gas upward in the reactor 3, fresh hydrogen sulfide gas is constantly supplied.

[0022] 3, the lithium hydroxide support member 7 is preferably provided with a plurality of communication holes 171. This is because the hydrogen sulfide gas supplied from the hydrogen sulfide supply pipe 5 is efficiently supplied to the lithium hydroxide filled 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 filled section 2.

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

[0025] In the lithium hydroxide-filled section 2 inside the reactor 3, the lithium hydroxide is preferably filled in layers so that the lithium hydroxide filled in layers 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] From the viewpoint of promoting the above reaction and preventing the lithium hydroxide from melting, the temperature of the lithium hydroxide-filled section 2 is usually adjusted to 100 to 445° C., and preferably 130 to 410° C. The temperature of the lithium hydroxide-filled section 2 is usually measured at the center of the lithium hydroxide-filled section 2 in the horizontal direction.

[0027] 2, the heat insulating member 6 is preferably provided with a plurality of communication holes 161. This is because by providing a plurality of communication holes 161 in the heat insulating member, exhaust gas containing unreacted hydrogen sulfide gas and 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] Examples of materials for the reactor 3 include metals and ceramics, but a sulfur-resistant material is preferred. 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] The inner surface of the reactor 3 is preferably subjected to sulfur-resistant treatment.

[0030] Examples of the anti-sulfuration treatment include plating with a metal or alloy having high anti-sulfuration properties, such as tin plating, chromium plating, gold plating, hot-dip aluminum plating, or alloy plating containing these metals.

[0031] Alternatively, a metal diffusion infiltration treatment may be used as a means of sulfur resistance treatment. It is known that when a metal diffusion infiltration treatment is performed on an object to be treated, a metal diffusion infiltration layer is formed on the surface of the object to be treated, thereby improving the sulfur resistance performance. For example, calorizing treatment, which is a diffusion and infiltration treatment of aluminum, can be used. In the calorizing treatment, the workpiece is embedded in a steel case together with a mixture consisting of Fe-Al alloy powder and NH4Cl powder, the case is sealed, and the case is heated in a furnace to form an aluminum diffusion and infiltration layer on the surface of the workpiece, thereby improving the sulfuration resistance of the workpiece.

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

[0033] That is, 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 accelerating the lithium sulfide production reaction.

[0034] The temperature of the jacket heater 4 is configured so as to be able to adjust the temperature of the lithium hydroxide-filled section 2 within the above-mentioned temperature range. Because the required heating temperature varies depending on the diameter of the lithium hydroxide-filled section 2 and the amount of catalyst filled, 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, in this embodiment, the jacket heater 4 is used as the heating means, but the heating means 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, or the like may also be used.

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

[0037] The hydrogen sulfide supply pipe 5 is preferably positioned below the lithium hydroxide support member 7. This is because hydrogen sulfide gas is supplied to the lithium hydroxide support member 7 from below, and thereby passes upward in the reactor 3, where it comes into contact with the lithium hydroxide filled in the lithium hydroxide filled section 2, thereby efficiently discharging water (water vapor), a by-product with a smaller specific gravity than hydrogen sulfide gas. Furthermore, by continuously passing hydrogen sulfide gas upward in the reactor 3, fresh hydrogen sulfide gas is constantly supplied.

[0038] 1, the hydrogen sulfide supply pipe 5 may have a hydrogen sulfide supply control valve 8 that adjusts the amount of hydrogen sulfide gas supplied. The amount of hydrogen sulfide supplied can be controlled by adjusting the opening and closing of the hydrogen sulfide supply control valve 8, which is advantageous from the viewpoint of controlling the lithium sulfide production reaction carried out in the reactor 3.

[0039] As the material of the hydrogen sulfide supply pipe 5, the materials mentioned above as the material of the reactor 3 can be used.

[0040] The hydrogen sulfide supply pipe 5 preferably has an inner surface that is anti-sulfurized. As a means for anti-sulfurization, the method described above as a method for anti-sulfurization of the inner surface of the reactor 3 can be used.

[0041] In addition, in this embodiment, the hydrogen sulfide supply pipe 5 is used as the hydrogen sulfide supply member, but this is not limited to this, and any hydrogen sulfide supply member may be used as long as it is capable of supplying hydrogen sulfide gas to the reactor 3.

[0042] (Insulating material 6) The heat 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] 1, the heat insulating member 6 is preferably configured to be located above the lithium hydroxide filled section 2 and to cover the entire lithium hydroxide filled section 2. In this way, heat release to the outside of the reactor 3 is further prevented.

[0044] 1, the side surface of the heat insulating member 6 is preferably provided so as to contact the inner wall of the reactor 3. In this way, the heat insulating member 6 is also heated, and the heat insulating member 6 itself has a certain heat capacity, so that the heat retention effect of the heat insulating member 6 is further enhanced.

[0045] 2, the heat insulating member 6 is preferably provided with a plurality of communication holes 161. By providing a plurality of communication holes 161 in the heat insulating member, 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] 2, the heat insulating member 6 may be provided with a temperature sensor through hole 162. In this case, the temperature sensor 9 inserted from above the reactor 3 passes through the temperature sensor through hole 162 and connects to the reactor 3.

[0047] As the material of the heat insulating member 6, the materials mentioned above as the material of the reactor 3 can be used.

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

[0049] If necessary, the heat insulating member 6 may be made of two or more layers of the porous material described above.

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

[0051] From the viewpoint of a balance between improving the insulation efficiency and recovering the exhaust gas and the like, the diameter of the communication holes 161 provided in the heat insulating member 6 is usually 26 μm or more and 10,000 μm or less, and preferably 45 μm or more and 5,000 μm or less.

[0052] From the viewpoint of improving the insulating efficiency, the thickness of the heat insulating member 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 heat insulating member 6, but it is usually 20 mm or less.

[0053] The heat insulating member may have an inverted funnel shape as shown in FIG. 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 section 2. In this case, by forming a gap between the temperature sensor 9 and the inner wall of the leg portion of the inverted funnel-shaped insulating member 46, the upper space and lower space of the inverted funnel-shaped insulating member 46 can communicate with each other through the gap.

[0054] (Lithium hydroxide support member 7) The lithium hydroxide support member 7 is a member on which lithium hydroxide is placed.

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

[0056] 3, the lithium hydroxide support member 7 is preferably provided with a plurality of communication holes 171. By providing the lithium hydroxide support member 7 with a plurality of communication holes 171, the hydrogen sulfide supplied from the hydrogen sulfide supply pipe 5 can be efficiently supplied to the lithium hydroxide filled section 2 through the plurality of communication holes 171.

[0057] As the material of the lithium hydroxide support member 7, the materials mentioned above as the material of the reactor 3 can be used.

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

[0059] If necessary, two or more sheets of the porous material described above may be stacked together to form the lithium hydroxide support member 7.

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

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

[0062] The gas exhaust pipe 10 is preferably positioned above the lithium hydroxide support member 7. This is because by-product water (water vapor) and unreacted hydrogen sulfide gas are vented toward the top of the reactor, and therefore, providing the gas exhaust pipe 10 at an upper position improves gas exhaust efficiency. Improved gas exhaust efficiency allows for a constant supply of fresh hydrogen sulfide gas.

[0063] It is preferable that the gas exhaust pipe 10 be provided with a cooling section that captures 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 produced 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 condensed water.

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

[0065] [Second embodiment] The apparatus for manufacturing lithium sulfide of the present embodiment may further include a heat transfer member 22 arranged in contact with or in the vicinity of the bottom surface of the lithium hydroxide loading section 2. Fig. 4 is a vertical cross-sectional view of an apparatus 21 for manufacturing lithium sulfide configured in this manner. By providing heat transfer member 22 below lithium hydroxide-filled section 2, heat from jacket heater 4 covering the outside of reactor 3 is more easily transferred in the horizontal direction of the cross section of lithium hydroxide-filled section 2, improving the thermal uniformity of lithium hydroxide-filled section 2 in the horizontal direction.

[0066] The heat transfer member 22 is preferably disposed so as to be in contact with the inner wall of the lithium hydroxide-filled section, in order to more efficiently transfer heat from the jacket heater 4 that covers the outside of the reactor 3.

[0067] It is preferable that a plurality of communication holes be provided in the heat transfer member 22. This is because by providing a plurality of communication holes in the heat transfer member, hydrogen sulfide supplied from the hydrogen sulfide supply pipe 5 can be efficiently supplied to the lithium hydroxide filled section 2 through the plurality of communication holes.

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

[0069] The shape of the heat transfer member 22 is not particularly limited, but is preferably one having a plurality of communicating holes, such as a punched metal. For example, one or more porous materials selected from metal meshes such as stainless steel mesh and aluminum mesh, punched metals such as stainless steel punched and aluminum punched, and expanded metals such as stainless steel expanded and aluminum expanded can be used.

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

[0071] The area ratio of the communicating holes provided in the heat transfer member 22 is typically 0.2% or more and 50% or less, and preferably 0.5% or more and 40% or less, from the viewpoint of balancing between improving heat transfer efficiency and improving 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 or more and 10,000 μm or less, and preferably 45 μm or more and 5,000 μm or less.

[0073] [Variations] The apparatus for manufacturing lithium sulfide according to the present embodiment may include components other than those described above.

[0074] Furthermore, in the apparatus for manufacturing lithium sulfide according to the present embodiment, the respective components may be integrally formed.

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

[0076] First, lithium hydroxide is filled into lithium hydroxide-filled section 2, and the lithium hydroxide-filled 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 lithium hydroxide-filled section 2, and the hydrogen sulfide gas is brought into contact with the lithium hydroxide, causing the lithium hydroxide and the hydrogen sulfide gas to react with each other to produce lithium sulfide.

[0077] A heat insulating member 6 is provided above the reactor 3 of the apparatus for manufacturing lithium sulfide 1, thereby preventing heat from being released to the outside of the reactor 3 and maintaining a high and uniform temperature throughout the lithium hydroxide filled section 2. Therefore, the apparatus for manufacturing lithium sulfide 1 can stably produce lithium sulfide with high efficiency.

[0078] In the lithium sulfide production process using the lithium sulfide production apparatus 1, the temperature inside the lithium hydroxide filling section 2 is generally 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 region. When the temperature inside lithium hydroxide filled section 2 is equal to or higher than the above lower limit value in the entire region, 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-filled section 2 is preferably 445°C or less, more preferably 430°C or less, and even more preferably 410°C or less, in all regions. When the temperature of the catalyst-filled section is equal to or less than the above upper limit in all regions, melting of the lithium hydroxide can be suppressed, and therefore, fusion between the lithium hydroxide particles and formation of clumps can be suppressed. This allows the reaction between the reaction gas and the lithium hydroxide to proceed more effectively.

[0080] In the lithium sulfide production process using the lithium sulfide production apparatus 1, the maximum temperature T max and the minimum temperature T min The difference (T max -T min ) is preferably 50°C or less, more preferably 30°C or less, and even more preferably 20°C or less, and is preferably as small as possible. max -T min When the temperature difference between the various points in the lithium hydroxide filled section 2 is small, that is, when the temperature difference between the various points in the lithium hydroxide filled section 2 is small, the reaction between the hydrogen sulfide gas and the lithium hydroxide can proceed more efficiently and stably.

[0081] The d50 of the weight-based particle size distribution of lithium hydroxide measured by a laser diffraction / scattering particle size distribution measurement method is preferably 1.5 mm or less, more preferably 1.0 mm or less. When the d50 is equal to or less than the upper limit, the contact area between lithium hydroxide and the reaction gas increases, accelerating the reaction, thereby further reducing the amount of unreacted raw material in the resulting lithium sulfide. As a result, lithium sulfide of higher purity can be obtained. Furthermore, the d50 of the weight-based particle size distribution of lithium hydroxide measured by a laser diffraction / scattering particle size distribution measurement method is preferably 0.1 mm or more, more preferably 0.2 mm or more. When the d50 is equal to or greater than the above-mentioned lower limit, it is possible to prevent water generated in the reaction system from adhering to the lithium sulfide particles and causing the particles to stick together. Furthermore, it is possible to prevent lithium hydroxide and the resulting lithium sulfide from being discharged together with the reaction gas, thereby simplifying exhaust gas treatment. Furthermore, it is possible to prevent lithium hydroxide and the resulting lithium sulfide from being scattered by the reaction gas, thereby improving the yield of lithium sulfide.

[0082] It is preferable to dehydrate the lithium hydroxide and dry the adhering water in advance. This can prevent the lithium hydroxide from agglomerating and inhibit the generation of hydrosulfides, thereby more effectively promoting the reaction between hydrogen sulfide gas and lithium hydroxide. Examples of methods for dehydrating and drying lithium hydroxide include heating in the atmosphere, heating while flowing a gas such as hydrogen, nitrogen, or argon gas, and heating under reduced pressure.

[0083] The hydrogen sulfide gas may be a commercially available product filled in a gas cylinder or the like, or may be produced in a hydrogen sulfide production apparatus connected upstream of the lithium sulfide production apparatus 1. When a hydrogen sulfide production apparatus is connected upstream of the lithium sulfide production apparatus 1, it is possible to generate only the amount of hydrogen sulfide gas required for producing lithium sulfide, eliminating the need to store hydrogen sulfide gas separately. Furthermore, because 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 as, for example, a positive electrode active material for batteries, a negative electrode active material, a solid electrolyte material, or an intermediate raw material for chemicals.

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

[0086] Example 1 The lithium sulfide manufacturing apparatus 31 was fabricated using the following components. FIG. 5 is a vertical cross-sectional view of the manufacturing apparatus 31. Reactor 3: A SUS316L reaction tube with an aluminum calorizing treatment applied to the inner wall for 450 mm from the bottom (inner diameter 124 mm, height 615 mm) Insulation material 36: Two aluminum plates (diameter 116 mm, thickness 0.5 mm, hole diameter 0.5 mm, hole diameter area ratio 27.9%) are placed on top of one aluminum punched metal (diameter 116 mm, thickness 0.5 mm, hole diameter 5 mm, hole diameter area ratio 1.7%), spaced 8 mm apart. Lithium hydroxide support member 37: #100 aluminum mesh layered on top of #300 SUS mesh Heat transfer member 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 the reactor 3, and a lithium hydroxide support member 37 was placed on top of the heat transfer member 22. 773 g of lithium hydroxide (particle size 0.05 to 0.75 mm) was packed on top of the lithium hydroxide support member 37. The height of the packed lithium hydroxide was 100 mm. Next, a heat transfer member 22 was placed on top of the lithium hydroxide packed.

[0088] Temperature sensor 9 was inserted through a temperature sensor through-hole provided in heat insulating member 36 and reached the bottom surface of lithium hydroxide filling section 2, i.e., lithium hydroxide support member 37, so that temperature sensor 9 could measure the temperature at each vertical point in the horizontal center of lithium hydroxide filling section 2.

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

[0090] Example 2 An apparatus for manufacturing lithium sulfide 41 was fabricated in the same manner as in Example 1, except that an inverted funnel-shaped insulating member 46 was used instead of the insulating member 36 as the insulating member, and temperature sensor 9 was inserted into the leg portion of the inverted funnel-shaped insulating member 46 and extended to reach lithium hydroxide support member 37. Lithium sulfide was then manufactured using the apparatus. Furthermore, a gap is formed between the temperature sensor 9 and the inner wall of the leg of the inverted funnel-shaped insulating member 46, and this gap allows the upper and lower spaces of the inverted funnel-shaped insulating member 46 to communicate with each other. FIG. 6 is a vertical cross-sectional view of the manufacturing apparatus 41.

[0091] (Comparative Example 1) An apparatus for manufacturing lithium sulfide 51 was fabricated in the same manner as in Example 1, except that the heat insulating member 36 and the heat transfer member 22 were omitted, and that the lithium hydroxide support member 57 was formed by placing a #300 SUS mesh on a SUS punched metal having a diameter of 123 mm, a thickness of 0.5 mm, and a pore size of 0.5 mm, and further placing a #100 aluminum mesh on the #300 SUS mesh. FIG. 7 is a vertical cross-sectional view of the manufacturing apparatus 51.

[0092] (Comparative Example 2) An apparatus 61 for producing lithium sulfide was fabricated in the same manner as in Example 1, except that the heat insulating member 36 was omitted, and lithium sulfide was produced. FIG. 8 is a vertical cross-sectional view of the manufacturing apparatus 61.

[0093] FIG. 9 shows a graph of the temperatures at various points in the lithium hydroxide loading section 2 measured by the temperature sensor 9 150 minutes after the start of heating in the lithium sulfide manufacturing apparatuses of Examples 1 and 2 and Comparative Examples 1 and 2.

[0094] According to FIG. 9, in the lithium sulfide manufacturing apparatuses of Examples 1 and 2, a high temperature was maintained even in the upper part of the lithium hydroxide filling section 2, and lithium sulfide could be produced stably with high efficiency, which is thought to be because the reaction field between hydrogen sulfide gas and lithium hydroxide was controlled at a high temperature with high precision.

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

[0096] [Table 1]

[0097] According to Table 1, in the lithium sulfide manufacturing apparatuses of Examples 1 and 2, T max -T min That is, in the lithium sulfide manufacturing apparatuses of Examples 1 and 2, the temperature variation at each point in the lithium hydroxide filling section 2 was small, so that lithium sulfide could be produced stably with high efficiency, and the reaction field between hydrogen sulfide gas and lithium hydroxide was controlled at a high temperature with high precision. [Explanation of symbols]

[0098] 1. Lithium sulfide manufacturing equipment 2 Lithium hydroxide filling section 3. Reactor 4 Jacket heater 5 Hydrogen sulfide supply pipe 6. Heat insulating materials 7 Lithium hydroxide support member 8 Hydrogen sulfide supply control valve 9 Temperature Sensor 10 Gas exhaust pipe 21 Lithium sulfide manufacturing equipment 22 Heat transfer material 31 Lithium sulfide manufacturing equipment 36 Heat insulating materials 37 Lithium hydroxide support member 41 Lithium sulfide manufacturing equipment 46 Heat insulating materials 51 Lithium sulfide manufacturing equipment 57 Lithium hydroxide support member 61 Lithium sulfide manufacturing equipment 161 Communication hole 162 Temperature sensor through hole

Claims

1. An apparatus for producing lithium sulfide by reacting hydrogen sulfide with lithium hydroxide, a reactor having a lithium hydroxide-filled portion therein; a heating means for heating the lithium hydroxide; a hydrogen sulfide supply member connected to the reactor; Equipped with a heat insulating member is provided inside the reactor above the lithium hydroxide-filled section, an upper space and a lower space of the heat insulating member are in communication with each other at a part of the heat insulating member or around the heat insulating member.

2. The lithium sulfide manufacturing apparatus according to claim 1, The apparatus for manufacturing lithium sulfide, further comprising a heat transfer member disposed in contact with or in proximity to a bottom surface of the lithium hydroxide filled section.

3. The apparatus for producing lithium sulfide according to claim 1 or 2, An apparatus for manufacturing lithium sulfide, the inner surface of which has been subjected to sulfur-resistant treatment.

4. A method for producing lithium sulfide, comprising reacting hydrogen sulfide gas with lithium hydroxide using the apparatus for producing lithium sulfide according to any one of claims 1 to 3.

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