Manufacturing method and using method of SnS2

Abstract

Provided is a method for efficiently producing high-purity SnS2. A method for producing SnS2, said method comprising a filtration step in which a SnS2 dispersion containing SnS2, a solvent, and impurities is passed through a filter material provided in a filter unit, and SnS2 aggregates are formed on the filter material; and a cleaning step for cleaning the SnS2 aggregate by passing a cleaning liquid through the SnS2 aggregate formed on the filter material.

Description

Technical Field

[0001] The present invention relates to SnS 2 Manufacturing method and use method. Background Art

[0002] In recent years, SnS has been used as a sintering aid for CZTS compound semiconductors (compound semiconductors using Cu, Zn, Sn, and S instead of silicon) and as a catalyst material for electrodes that can be used in solar cells. 2 (tin disulfide (IV)) has attracted attention. In addition, the use of SnS 2 Lithium is suitable for use as a solid electrolyte. 4 S N 4 For SnS 2 The manufacturing method was studied.

[0003] Non-patent document 1 discloses the following method: 2 S aqueous solution and SnCl 4 The aqueous solution was mixed to obtain SnS containing NaCl 2 After the dispersion, the dispersion was washed about 5 times using a centrifugal sedimentation machine to remove NaCl, thereby producing SnS 2 .

[0004] Prior art literature Non-patent literature Non-patent literature 1: Solid State Ionics, 2020, vol. 345, 115190 Summary of the invention Technical problem to be solved by the invention In the method described in Non-Patent Document 1, in order to improve the cleaning performance, it is necessary to 2 The agglomerates of SnS are broken and dispersed in water. However, the inventors have found that the SnS 2 Since a strong agglomerate is formed, it cannot be dispersed by immersing in water alone, and a strong force needs to be physically applied to break the agglomerate by using a strong crusher, etc. Therefore, it can be seen that when the method described in non-patent document 1 is used for mass production, a process of breaking the agglomerate is required, and this method has the problem of low manufacturing efficiency.

[0005] Therefore, the object of the present invention is to provide a method for efficiently producing high-purity SnS 2 In addition, the present invention aims to provide a SnS obtained by the above method. 2 How to use it.

[0006] Technical solutions for solving technical problems The present invention is a SnS 2 A manufacturing method comprising: The filtering step includes: 2 , solvents and impurities SnS 2 The dispersion passes through the filter material provided in the filter unit, and SnS is formed on the filter material. 2 Agglomerates; and A cleaning step, wherein a cleaning liquid is passed through the SnS 2 Agglomerates are cleaned by 2 Agglomerate.

[0007] In addition, the present invention is a SnS 2 A method of using the SnS manufactured by the above method 2 A step of contacting with a sulfide containing an alkali metal to obtain a compound containing an alkali metal, tin and sulfur.

[0008] Effects of the Invention According to the present invention, high-purity SnS can be efficiently produced. 2 In addition, according to the present invention, the SnS obtained by the above method can be used 2 To make compounds containing alkali metals, tin and sulfur. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a diagram showing a reaction process according to one embodiment of the present invention.

[0010] Figure 2 It is a schematic diagram explaining the filtration process of one embodiment of the present invention.

[0011] Figure 3 It is a schematic diagram explaining the filtration process of one embodiment of the present invention.

[0012] Figure 4 It is a schematic diagram explaining the cleaning process of one embodiment of the present invention.

[0013] Figure 5 This is a schematic diagram showing the structure of the filter medium portion of the filter press.

[0014] Figure 6 Na is a method for explaining one embodiment of the present invention. 4 S N 4 and Na 2 S N 3 Schematic diagram of the manufacturing process. DETAILED DESCRIPTION

[0015] <SnS 2Manufacturing method> According to the present invention, SnS 2 The manufacturing method comprises the following steps: Filtration step, wherein the SnS 2 , solvents and impurities SnS 2 The dispersion passes through the filter material provided in the filter unit, and SnS is formed on the filter material. 2 A cleaning step is to pass a cleaning liquid through the SnS formed on the filter material. 2 Agglomerates, cleaning the SnS 2 In addition, the SnS 2 The manufacturing method may include a drying step, wherein the SnS 2 The aggregate is dried. Each step is described in detail below.

[0016] [Filtration process] In the filtration process, the SnS 2 , solvents and impurities SnS 2 The dispersion passes through the filter material provided in the filter unit. Thus, SnS is formed on the filter material. 2 Agglomerate.

[0017] (SnS 2 Dispersion S N 2 The dispersion contains at least SnS 2 , solvents and impurities. SnS 2 The dispersion can be prepared by a known method. As an example, Na 2 S and SnCl 4 Prepared in a solvent based on the following reaction (refer to Figure 1 ). Alternatively, Li 2 S and other alkali metal sulfides to replace Na 2 S, but Na is preferred from the viewpoint of versatility. 2 S.

[0018] 2Na 2 S+SnCl 4 →SnS 2 +4NaCl Examples of the solvent include water; alcohols such as methanol and ethanol; water-soluble organic solvents such as acetone; and mixed solvents thereof. The solvent preferably contains water. Examples of water include pure water or ultrapure water. In addition, from the viewpoint of suppressing the deterioration of the target object and the decrease in purity, the conductivity of the solvent (preferably water) is preferably less than 10 μS / cm, and the dissolved oxygen concentration in the solvent (preferably water) is preferably less than 10 mg-O / L. SnS2 Each raw material used in the preparation of the dispersion can be an anhydrous substance or a hydrate. Each raw material can be mixed in a solid form and then a solvent is added to react it, or a solvent can be added to at least one of them to form a solution or a dispersion for reaction, preferably in the form of a solution obtained by dissolving each raw material in the above-mentioned solvent for reaction. In this case, the concentration of each raw material in the solution is not particularly limited, for example, it can be set to 1% by mass to 40% by mass.

[0019] SnS prepared as described above 2 The impurities contained in the dispersion are mainly NaCl, and in addition, unreacted raw materials (such as Na 2 S, SnCl 4 ) etc. It should be noted that when other raw materials are used to replace Na 2 S and SnCl 4 In the case of using other raw materials, salts derived from the other raw materials may be obtained as impurities.

[0020] For example, when Na 2 S aqueous solution and SnCl 4 When aqueous solutions are mixed, the generated SnS 2 The SnS is dispersed in the dispersion as a precipitate, and the NaCl as an impurity is dissolved in the aqueous solution. 2 The dispersion liquid passes through the filter material provided in the filtration unit. 2 Accumulates on the filter material to form SnS 2 On the other hand, most of the impurities including NaCl dissolved in the dispersion are discharged as filtrate. SnS 2 SnS in dispersion 2 The concentration of is not particularly limited and can be appropriately set, and can be, for example, 1% by mass to 15% by mass.

[0021] (Filter unit) The filtering unit is not particularly limited, and known means such as centrifugal filters using a heavy pressure filtration method, drum filters using a vacuum filtration method, and filter presses using a pressure filtration method can be used. Among them, in the present invention, from the viewpoint of cleaning efficiency, a filter press is preferably used. When a filter press is used, the rupture of the agglomerate is not easy to occur during filtration, and the cleaning property can be improved. When a filter press is used as a filtering unit, filter cloths and the like can be cited as filtering materials. When a drum filter is used as a filtering unit, filter cloths and the like can be cited as filtering materials. In addition, when a centrifugal filter is used as a filtering unit, filter cloths, metal filters and the like can be cited as filtering materials. It should be noted that in this specification, a centrifugal filter is a device in which a rotating body (basket) has holes for filtering materials and liquids to pass through. In a centrifugal filter, the treated liquid (dispersion liquid, etc.) is passed through a filter material arranged on the inner side of a basket having holes on the wall surface, thereby separating the solids and liquids in the treated liquid, and then, water with a mesh smaller than the mesh of the filter material is discharged outward from the holes of the basket, thereby enabling solid-liquid separation. On the other hand, the centrifugal sedimentation machine used in Non-Patent Document 1 is a device in which a rotating body (basket) does not have a filter material (filter) and holes for liquid to pass, a heavy liquid (liquid or crystals (filter cake)) is formed on the wall surface of the rotating body and is precipitated, and a light liquid is formed thereon, thereby performing solid-liquid separation or liquid-liquid separation without using a filter material.

[0022] If the SnS formed on the filter material during the filtering process 2 If the thickness of the aggregate is too large, the efficiency of the cleaning liquid in the cleaning step described later will be reduced. 2 The thickness of the aggregate is as described below, preferably the thickness of the washed SnS 2 The thickness of the aggregate was adjusted to 1 to 100 mm in the vertical direction of the filter surface of the filter material. 2 SnS agglomerates and before cleaning 2 Agglomerates (SnS formed during the filtration process 2 There is a difference in the degree of impurity removal compared to the SnS aggregate after cleaning. 2 The thickness of the aggregate can be regarded as the thickness of SnS before cleaning. 2 The thickness of the aggregates is roughly the same. 2 When the thickness of the aggregate exceeds the above range, SnS 2 The dispersion was filtered separately.

[0023] Figure 2 Schematic diagram showing a filtration process according to an embodiment of the present invention. In this embodiment, the filtration process is carried out, for example, as follows. Step 1: Filtering SnS from a stored 2The dispersion liquid tank 1 is used to pump the SnS 2 The dispersion is passed through the filter material 2 in a cyclic manner or in a one-way manner, thereby forming SnS on the filter material. 2 In addition, when storing SnS 2 The stock liquid tank 1 of the dispersion liquid is equipped with a stirrer (not shown). 2 The circulation or one-way flow of the dispersion can be controlled by using a valve (not shown). 2 In the case of filtration of the dispersion, SnS 2 After the dispersion is passed through the filter material, SnS 2 The dispersion (formed SnS 2 SnS before condensation 2 A portion of the dispersion may flow through the filter material (filter cloth) to the filtrate side. This is because the filter cloth equipped with the filter press has a smaller mesh than SnS 2 The particle size of the dispersion is slightly larger. During the filtration process, SnS 2 The particles of the dispersion gradually clog the mesh of the filter cloth, eventually forming SnS on the filter material. 2 Therefore, by 2 The dispersion is circulated to recover the SnS that flows into the filtrate at the beginning of the filtration process. 2 .SnS 2 The dispersion can be passed in one direction or in a circulation manner. However, according to the circulation method, almost all SnS can be recovered. 2 Agglomerate. Process 2: SnS 2 After the recovery of the aggregates is completed, the filtrate (mainly containing NaCl) is recovered in the waste liquid tank 3 and discharged as waste liquid. Alternatively, the filtrate may be discharged without passing through the filtration unit using a pipe (not shown).

[0024] Figure 3 Schematic diagram showing the filtration process of another embodiment of the present invention. In this embodiment, the filtration process is carried out as follows. Step 1: 2 The dispersion liquid tank 1 is used to pump the SnS 2 The dispersion liquid is passed through the filter material 2 in one direction, thereby forming SnS on the filter material. 2 Agglomerates. At this time, the filtrate is stored in the filtrate tank 4 of the rear stage. 2 The original liquid tank 1 for the dispersion and the filtrate tank 4 for storing the filtrate are equipped with a stirrer (not shown). 2The dispersion is in a state where a little bit of it remains in the stock liquid tank 1 and the filtrate tank 4. Step 2: Next, the filtrate is transferred from the filtrate tank 4 to the stock liquid tank 1 using the pump P2 to remove the remaining SnS 2 The dispersion is recovered in the stock solution tank 1. Step 3: The recovered SnS-containing 2 Dispersion of SnS 2 The recovery liquid is circulated or passed one-way from the original liquid tank 1 to the filter material 2, thereby removing SnS 2 Dispersion as SnS 2 According to this method, although the equipment is increased by adding steps 1 and 2, almost all SnS can be recovered. 2 Agglomerates, and Figure 2 Compared with the method shown in the figure, the filtration efficiency can be improved. 2 The circulation or one-way flow of the recovery liquid can be controlled by using a valve not shown.

[0025] [Cleaning process] Impurities such as NaCl are discharged as filtrate during the filtration process, but SnS 2 There are still impurities such as NaCl remaining in the condensate. Figure 4 As shown, in the cleaning process, by passing the cleaning liquid through the SnS 2 Agglomerates to clean SnS 2 Thus, the cleaned SnS with reduced impurities is obtained. 2 In addition, the cleaning liquid can be added with SnS in the filtering process. 2 The dispersion liquid may be supplied from the stock liquid tank or from other pipes. Furthermore, the waste liquid may be stored in the filtrate tank or waste liquid tank in the filtration step or discharged from other pipes.

[0026] Here, in the method described in Non-Patent Document 1, the following steps are carried out using a centrifugal sedimentation machine to remove SnS 2 The NaCl contained in the dispersion liquid is used to obtain the target SnS 2 .

[0027] 1. Add SnS 2 The dispersion is placed in a centrifuge tube provided in a centrifugal sedimentation machine; 2. Place the centrifuge tube in a centrifugal sedimentation machine and rotate at 3000-10000 rpm for 5 minutes; 3. Discard the supernatant containing NaCl (SnS 2 The aggregates remain at the bottom of the centrifuge tube); 4. Add water to the centrifuge tube to soak SnS 2 Agglomerates; 5. The SnS impregnated 2 The water in the aggregate is used as SnS in step 1 2 Using the dispersion, repeat steps 1 to 4 (about 5 times in total).

[0028] As described above, in the method described in Non-Patent Document 1, in the above-mentioned steps 2 and 3, since a centrifugal sedimentation machine is used to clean the SnS 2 Agglomerates, so the SnS 2 The aggregates form solid blocks, and repeated washing alone cannot fully disperse such solid SnS 2 Agglomerates, difficult to fully clean into SnS 2 Therefore, in order to remove impurities mixed into SnS 2 Impurities in the aggregate need to be removed by using, for example, an ultrasonic homogenizer. 2 After the agglomerates are broken, they are dispersed again in the dispersion liquid. On the other hand, in the present invention, it is preferred to use a filter press to filter the SnS 2 The dispersion is filtered to remove the SnS 2 The agglomerates are washed on the filter material. In the present invention, even without crushing the SnS 2 The process of agglomeration can also reduce and remove SnS 2 Impurities in the aggregate can efficiently produce high-purity SnS 2 That is, the cleaning step of the present invention preferably does not contain pulverized SnS 2 Agglomeration process.

[0029] (Cleaning fluid) As long as the cleaning fluid can be removed from SnS 2 There is no particular limitation on the impurities to be removed from the agglomerate, and examples thereof include water; alcohols such as methanol and ethanol; water-soluble organic solvents such as acetone; and mixed solvents thereof. 2 The solvent contained in the dispersion may be the same or different. However, from the perspective of simplifying the production method, the cleaning liquid is preferably the same as the SnS 2 The solvent contained in the dispersion is the same, preferably water. As water, pure water or ultrapure water can be mentioned. In addition, from the viewpoint of suppressing the deterioration of the target object and the reduction of purity, the conductivity of the cleaning liquid (preferably water) is preferably less than 10 μS / cm, and the dissolved oxygen concentration in the cleaning liquid (preferably water) is preferably less than 10 mg-O / L.

[0030] Pass the cleaning solution through the SnS on the filter material 2The method of forming the aggregate is not limited. For example, a method can be used in which the cleaning liquid is stored in a tank and the cleaning liquid is pumped from the tank to the SnS 2 Agglomerate method, pressurizing the tank with inert gas or the like to deliver the cleaning liquid to the SnS 2 Agglomeration method, etc. The flow rate of the cleaning liquid is as long as it can be 2 The amount of the cleaning liquid is not particularly limited as long as it can remove impurities from the agglomerates and can be determined by taking into account the pressure loss and the cleaning time. 2 The impurities in the aggregate can be removed without any particular limitation. SnS 2 , cleaning time. In addition, during the flow of the cleaning liquid, it is preferred to always measure the impurity concentration in the outflowing cleaning liquid. The method of always measuring the impurity concentration in the outflowing cleaning liquid is not particularly limited. For example, a method of always measuring the impurity concentration in the outflowing cleaning liquid by connecting a conductivity meter to the piping for measurement can be cited.

[0031] In the present invention, the cleaning process may be performed only once or repeatedly. However, according to the present invention, by performing the cleaning process once, SnS 2 The impurities are fully removed from the agglomerate.

[0032] After the cleaning process, the cleaned SnS 2 The thickness of the aggregate is preferably 1 to 100 mm in the vertical direction of the filter surface of the filter material from the viewpoint of washability. It should be noted that the filter material sometimes has more than one filter surface. When the filter material has more than one filter surface, the maximum thickness of the vertical direction of the plurality of filter surfaces is preferably within the above range. Figure 5 This is a schematic diagram showing the structure of the filter material (filter cloth) part of the filter press. Figure 5 In the filter, there is a slit-shaped groove (not shown) between the filter plate and the filter cloth, and the filtrate (washing liquid) flows in this part. Figure 5 In the filter materials shown, the filter cake (SnS 2 The left and right sides of the paper surface of the aggregate are the filtering surface, and the thickness in the direction perpendicular to the filtering surface is equivalent to the lateral width of the filter cake ( Figure 5 d) in.

[0033] [Drying process] According to the present invention, SnS 2 The manufacturing method may include a drying step, wherein the drying step is performed on the cleaned SnS 2 The agglomerate is dried. By performing the drying process, SnS 2 The solvent in the aggregate is removed, and SnS can be separated2 The specific operation of the drying process is not particularly limited, and one or more of the conventionally known methods may be used in combination. Specifically, the drying method includes reduced pressure drying (including freeze drying) and spray drying. Among them, reduced pressure drying is preferred. 2 From the viewpoint of preventing deterioration of SnS, the drying process is preferably carried out at a pressure of less than 5 kPa. Alternatively, the drying process may be carried out under reduced pressure while heating. In this case, the heating temperature may be set to 40°C to 80°C, for example. In either case, it is preferred that the SnS 2 Appropriate conditions are set according to the type of solvent contained in the aggregate.

[0034] SnS obtained by the method of the present invention 2 For example, it can be identified by elemental analysis such as fluorescent X-ray analysis, X-ray diffraction measurement, infrared absorption spectrum, Raman spectrum measurement, and the like.

[0035] <SnS 2 How to use> According to the present invention, SnS 2 The method for using the SnS manufactured by the above method comprises the following steps: 2 The SnS of the present invention is contacted with a sulfide containing an alkali metal to obtain a compound containing an alkali metal, tin and sulfur. 2 The usage of SnS can also be said to be 2 A method for producing a compound containing an alkali metal, tin and sulfur by using a sulfide containing an alkali metal. As the sulfide containing an alkali metal, an alkali metal sulfide is preferred, and as the alkali metal, Na, Li and K are preferred. Examples of the alkali metal sulfide include Li 2 S, Na 2 S and K 2 S.

[0036] Make SnS 2 The method of contacting with the sulfide containing the alkali metal is not particularly limited. 2 The sulfide containing an alkali metal may be mixed in solid form and a solvent may be added to react, or a solvent may be added to at least one of them to react in the form of a solution. Examples of the solvent include water; alcohols such as methanol and ethanol; water-soluble organic solvents such as acetone; and mixed solvents thereof. The solvent may be mixed with the above-mentioned SnS 2 SnS used in the manufacturing method 2 The solvents contained in the dispersion may be the same or different. 2 Manufacturing method for manufacturing SnS 2 , the obtained SnS 2When directly used in this method, the solvent used in this method is preferably the same as the above SnS 2 The solvent contained in the dispersion is the same, preferably water. As water, pure water or ultrapure water can be mentioned. In addition, from the viewpoint of suppressing the deterioration of the target object and the reduction of purity, the conductivity of the solvent (preferably water) is preferably less than 10 μS / cm, and the dissolved oxygen concentration in the solvent (preferably water) is preferably less than 10 mg-O / L.

[0037] As SnS 2 Compounds containing an alkali metal, tin, and sulfur obtained by contacting with a sulfide containing an alkali metal include, for example, the following compounds. Compounds containing sodium, tin, and sulfur (e.g., Na 4 S N 4 、Na 2 S N 3 ), compounds containing lithium, tin, and sulfur (such as Li 4 S N 4 , Li 2 S N 3 ) etc. The obtained compound containing alkali metal, tin and sulfur can be identified by, for example, elemental analysis based on fluorescent X-ray analysis, measurement of X-ray diffraction, infrared absorption spectrum, Raman spectrum measurement, etc.

[0038] (Na 4 S N 4 Manufacturing) As an implementation example, refer to Figure 6 SnS 2 As a sulfide containing alkali metals, Na 2 S contact to make Na 4 S N 4 First, prepare water to dissolve Na in a tank. 2 S 2 S aqueous solution. 2 Na in S aqueous solution 2 The concentration of S is not particularly limited and can be appropriately set, for example, 1 mass % to 20 mass %. Next, the SnS on the filter material after washing produced by the method of the present invention is 2 Agglomerates, with the SnS 2 and Na 2 NaS was introduced in a molar ratio of 1:2 2 S aqueous solution. Thus, Na is generated according to the following reaction formula 4 S N 4 The obtained Na 4 S N 4 The aqueous solution is light yellow. It should be noted that this reaction can be used, for example, in the production of SnS2 The agglomerate is directly carried out in the filter press device.

[0039] S N 2 +2Na 2 S→Na 4 S N 4 In addition, Na is generated by the above reaction. 4 S N 4 , but in fact, it is speculated that until SnS 2 and Na 2 Until the molar ratio of S reaches 1:1, Na 2 S N 3 . 2 S N 3 Soluble in water, therefore, when SnS on the filter material 2 with Na 2 S reacts to form Na 2 S N 3 When 2 S N 3 Flow to the filtrate. Therefore, for SnS 2 Agglomerates, using the SnS 2 and Na 2 The molar ratio of S is 1:2. 2 When S aqueous solution is passed, Figure 6 As shown, it is preferred to circulate the filtrate (store the filtrate in a container containing Na 2 S aqueous solution in the tank) and used again with SnS 2 Thus, the previously generated Na 2 S N 3 Converted to Na 4 S N 4 , ultimately, the consumed SnS 2 and Na 2 When the molar ratio of S becomes 1:2, Na 4 S N 4 As the main product. It should be noted that Figure 6 In the apparatus shown, the circulation of the filtrate can be controlled by appropriate use of valves (not shown).

[0040] In addition, it is also preferred to produce Na in two stages by the following steps: 4 S N 4 First, as the first stage of the process, the cleaned SnS 2 Agglomerates, with the SnS 2 and Na 2The molar ratio of S is 1:1, and the Na in the circulation tank is 2 S aqueous solution. 2 S aqueous solution tank, obtained with Na 2 S N 3 Next, as the second step, the generated Na 2 S N 3 and Na 2 The molar ratio of S to Na is 1:1 2 S reacts with the circulating fluid in the tank again. 2 S N 3 Obtaining Na 4 S N 4 .

[0041] (Na 2 S N 3 Manufacturing) In the above Na 4 S N 4 In the manufacture of 2 and Na 2 The molar ratio of S to Na is 1:1 2 S, can get Na 2 S N 3 That is, first, prepare water to dissolve Na 2 S 2 S aqueous solution. Then, Figure 6 As shown, for the cleaned SnS on the filter material manufactured according to the method of the present invention, 2 Agglomerates to make the SnS 2 and Na 2 The molar ratio of S is 1:1, and the Na 2 S aqueous solution. 2 The Na 2 S N 3 Aqueous solution. The obtained Na 2 S N 3 The aqueous solution is light yellow.

[0042] In addition, for SnS 2 , so that the molar ratio exceeds 1:1 2 When S reacts, Na 4 S N 4 Therefore, in the production of Na 2 S N 3 In order to reliably inhibit Na 4 S N 4The generation of Na 2 S relative to SnS 2 The amount used is less than the theoretical amount, i.e., 1 times the molar amount, so that the unreacted SnS 2 Remains on the filter material. Here, it is not limited to Na 2 S N 3 For the manufacture of cleaned SnS on the filter material 2 Aggregates, using Na 2 After the S aqueous solution is passed, sometimes SnS 2 The aggregates collapse and part of them return to particles, which flow into the filtrate through the filter material. 2 S relative to SnS 2 When the amount used is less than 1 times the molar amount, the unreacted SnS discharged into the filtrate can be recovered by filtering using MF (microfiltration), UF (ultrafiltration), etc. 2 .

[0043] As mentioned above, when Na 2 S relative to SnS 2 When the amount of SnS used is adjusted to less than the theoretical amount, unreacted SnS will remain on the filter material. 2 Agglomerates. It is also possible to 2 In the state of agglomeration, the above SnS 2 SnS in the manufacturing method 2 The dispersion liquid is passed through the liquid, and the above-mentioned cleaning step (NaCl removal step) is repeated. 2 The unreacted SnS remaining on the filter material is removed by a dissolving liquid such as an aqueous S solution. 2 The aggregate is cleaned.

[0044] The above Na 4 S N 4 and Na 2 S N 3 The method of manufacturing the above-mentioned compound is also applicable to the manufacture of compounds containing other alkali metals, tin and sulfur. The compound containing alkali metals, tin and sulfur thus obtained can be used as a solid electrolyte such as Li 4 S N 4 , LGPS (lithium-germanium-phosphorus-sulfur) solid electrolyte, raw materials for thio-LISICON, etc.

[0045] Example [Example 1] (Filtration process) Will Na 2 S·9H 2O was dissolved in water (dissolved oxygen concentration: less than 10 mg-O / L, conductivity: less than 10 μS / cm) to prepare 12% by mass Na 2 Next, SnCl 4 ·5H 2 O was dissolved in water (dissolved oxygen concentration: less than 10 mg-O / L, conductivity: less than 10 μS / cm) to prepare 28 mass% SnCl 4 Aqueous solution (B).

[0046] While A is being cooled, stirring is continued until the Na 2 S: SnCl in B 4 =2:1 molar ratio, B was added dropwise little by little and mixed to obtain 8 mass % SnS containing NaCl as an impurity. 2 Dispersion (C).

[0047] C in the filtration area of ​​0.1m 2 The filter press device is passed through the liquid, thereby making SnS 2 Particles accumulate on the filter material, forming SnS before cleaning 2 Agglomerate (D). It should be noted that SnS 2 Dispersion liquid (C) flow Figure 2 The device shown is operated by one-way liquid flow.

[0048] (Cleaning process) After passing water (dissolved oxygen: less than 10 mg-O / L, conductivity: less than 10 μS / cm) to D for 3 hours, it was squeezed to obtain the cleaned SnS 2 Aggregate (E). About the obtained cleaned SnS 2 Agglomerates (E), the thickness of the filter material in the vertical direction of the filter surface ( Figure 5 d) in the figure is 10mm.

[0049] (analyze) E was taken out from the filter press device, added to water (dissolved oxygen: less than 10 mg-O / L, conductivity: less than 10 μS / cm), and crushed using an ultrasonic homogenizer (trade name: LUH300, manufactured by Yamato Scientific Co., Ltd.), thereby obtaining 8 mass % SnS with a reduced amount of NaCl. 2 Dispersion liquid (F) F was filtered using a hydrophilic PVDF membrane filter with a pore size of 0.1 μm to prepare a filtrate (G), and the concentrations of Na and Cl in the filtrate (G) were analyzed by capillary electrophoresis.

[0050] [Example 2] The cleaned SnS was obtained by the same method as in Example 1.2 Agglomerate (E).

[0051] E was dried under reduced pressure at 80°C and less than 2 kPa to produce SnS 2 Dried body (H) (drying step).

[0052] [Example 3] The cleaned SnS was obtained by the same method as in Example 1. 2 Agglomerate (E).

[0053] E was dried under reduced pressure at 80°C and 7 kPa to produce SnS 2 Dried body (H) (drying step).

[0054] [Example 4] The cleaned SnS was obtained by the same method as in Example 1. 2 Agglomerate (E).

[0055] Relative to E, ready to be Na in E:A 2 S = 1:2 molar ratio of the amount of A, such as Figure 6 As shown, by circulating the filtrate through the filter material again, SnS 2 with Na 2 Thus, 15% to 20% by mass of Na 4 S N 4 Aqueous solution (I).

[0056] [Example 5] The cleaned SnS was obtained by the same method as in Example 1. 2 Agglomerate (E).

[0057] Relative to E, ready to be Na in E:A 2 S = 1:1 molar ratio of the amount of A, such as Figure 6 As shown, by circulating the filtrate through the filter material again, SnS 2 with Na 2 Thus, 20 to 30% by mass of Na 2 S N 3 Aqueous solution (J).

[0058] [Comparative Example 1] In the same manner as in Example 1, 8 mass % SnS containing NaCl was prepared. 2 Dispersion (C).

[0059] Place C in a centrifuge tube and spin it at 3000-10000 rpm for 5 minutes to make SnS2 The aggregates settle to the bottom of the centrifuge tube. The supernatant is discarded to obtain the cleaned SnS 2 Agglomerates (E) (cleaning process).

[0060] Water (dissolved oxygen: less than 10 mg-O / L, conductivity: less than 10 μS / cm) was added to E, and the mixture was crushed using the same ultrasonic homogenizer as in Example 1 to obtain 8% by mass SnS with a reduced amount of NaCl. 2 Dispersion (F) (crushing step).

[0061] F was filtered using a hydrophilic PVDF membrane filter having a pore size of 0.1 μm to prepare a filtrate (G). The concentrations of Na and Cl in the filtrate (G) were analyzed in the same manner as in Example 1.

[0062] [Comparative Example 2] The SnS obtained in Comparative Example 1 2 The dispersion (F) was put into a centrifuge tube again, and the washing process using a centrifugal sedimentation machine and the crushing process using an ultrasonic homogenizer were repeated 4 times (the total number of crushing processes was 5 times), and SnS with a reduced amount of NaCl by 8 mass% was obtained. 2 Dispersion (F).

[0063] F was filtered through a hydrophilic PVDF membrane filter with a pore size of 0.1 μm to prepare a filtrate (G), and the concentrations of Na and Cl in the filtrate (G) were analyzed in the same manner as in Example 1. It should be noted that in this Comparative Example 2, the total number of crushing steps was 5 times, but the last crushing was for analyzing the concentrations of Na and Cl, so the crushing was repeated until the cleaned SnS 2 The number of crushing steps to the aggregate (E) was 4.

[0064] [Comparative Example 3] The cleaned SnS was obtained by the same method as in Comparative Example 2 (cleaning step: 5 times). 2 Agglomerate (E).

[0065] For E, mix A in a beaker until it becomes E: Na in A 2 S=1:2 molar ratio, prepare 15~20 mass% Na 4 S N 4 Aqueous solution (I).

[0066] For the cleaned SnS obtained in the examples and comparative examples 2 Agglomerate (E), filtrate (G), SnS 2 Dry body (H), Na 4 S N 4 Aqueous solution (I) and Na 2 S N3 The aqueous solution (J) is shown in Table 1 in terms of the state of matter, hardness, color, thickness from the filtration surface, metallic luster, turbidity, and concentrations of Na and Cl.

[0067] [Table 1] As shown in Table 1, by comparing the concentrations of Na and Cl in the filtrates (G) obtained in Example 1, Comparative Example 1, and Comparative Example 2, it is possible to relatively compare the concentrations of SnS after cleaning. 2 Purity of the aggregate (E). From the comparison between Example 1 and Comparative Example 1, it can be seen that the SnS 2 The manufacturing method of the present invention is a manufacturing method with overwhelmingly excellent cleaning performance compared to the method of the prior art (Comparative Example 1). In addition, as can be seen from the comparison between Example 1 and Comparative Example 2, according to the present invention, in the method described in Non-Patent Document 1, the amount of impurities can be reduced to less than 1 / 5 to 1 / 10 compared to the case where the process of crushing the aggregate is performed every time the cleaning is performed. The present invention is a method that can manufacture SnS with high purity compared to the prior art. 2 Assume that SnS with the same purity as the present invention is to be produced based on the prior art method. 2 In this case, the five cleaning steps performed in Comparative Example 2 need to be repeated at least six times, further reducing the manufacturing efficiency.

[0068] In addition, from the comparison between Example 2 and Example 3, it can be seen that SnS 2 The state of the dried product (H) changes greatly depending on the pressure during drying. That is, the H obtained in Example 2 is a yellow-brown dry solid, and the H obtained in Example 3 is a black-brown dry solid with a metallic luster. During the drying process, SnS 2 The reason is not clear, but it is speculated that in Example 2, by further reducing the pressure during drying, SnS 2 The reaction with oxygen decreases, SnS 2 Altogether, it is known that by using the present invention, it is also possible to produce high-purity SnS 2 of dry body.

[0069] From the comparison between Example 4 and Comparative Example 3, it can be seen that the SnS 2 As with the prior art, it can be used for Na as a compound containing alkali metals, tin and sulfur. 4 S N 4 The Na obtained in Example 4 and Comparative Example 3 4 S N 4The aqueous solution (I) differed only in the production method, and no change in color was observed. Therefore, it was found that although the purity was different, it contained essentially the same compound (Na 4 S N 4 ). That is, it is known that SnS produced by the method of the present invention 2 and SnS manufactured by a prior art method 2 The compounds are the same except for the purity. However, the presence or absence of the crushing step and the number of crushing steps show that according to the present invention, the SnS 2 By breaking up the aggregates, high-purity SnS can be produced efficiently. 2 .

[0070] Furthermore, as shown in Example 5, it can be seen that the SnS produced by the method according to the present invention 2 By using Na in a molar ratio different from that of Example 4 2 The reaction of S can also be used for Na 2 S N 3 The Na obtained by the present invention 2 S N 3 with Na 4 S N 4 It can also be used as a raw material for solid electrolytes.

[0071] Although the present invention has been described above with reference to the embodiment examples, the present invention is not limited to the above-described embodiment. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0072] This application claims priority based on Japanese patent application No. 2022-191495 filed on November 30, 2022, the entire disclosure of which is incorporated herein by reference.

[0073] The present invention includes the following configurations.

[0074] [Composition 1] A SnS 2 A manufacturing method, comprising: The filtering step includes: 2 , solvents and impurities SnS 2 The dispersion passes through the filter material provided in the filter unit, and SnS is formed on the filter material. 2 Agglomerates; and The cleaning step comprises passing a cleaning liquid through the SnS 2 Agglomerates are cleaned by 2 Agglomerate.

[0075] [Composition 2] According to the SnS of configuration 1 2 The production method, wherein the solvent contains water.

[0076] [Composition 3] SnS according to configuration 1 or 2 2 The manufacturing method, wherein the conductivity of the solvent is less than 10 μS / cm.

[0077] [Composition 4] The SnS according to any one of configurations 1 to 3 2 The manufacturing method, wherein the cleaned SnS 2 The thickness of the agglomerate in the vertical direction of the filter surface of the filter material is 1 mm to 100 mm.

[0078] [Composition 5] The SnS according to any one of configurations 1 to 4 2 The manufacturing method, wherein the cleaning liquid contains water.

[0079] [Composition 6] The SnS according to any one of configurations 1 to 5 2 The manufacturing method, wherein the conductivity of the cleaning liquid is less than 10 μS / cm.

[0080] [Composition 7] The SnS according to any one of configurations 1 to 6 2 The manufacturing method comprises a drying step, wherein the drying step is performed on the cleaned SnS obtained in the cleaning step at a pressure less than 5 kPa. 2 The aggregate is dried.

[0081] [Composition 8] A SnS 2 A method of using the SnS prepared by the method described in any one of the above-mentioned steps 1 to 7 2 A step of contacting with a sulfide containing an alkali metal to obtain a compound containing an alkali metal, tin and sulfur.

[0082] Description of Reference Numerals 1: Liquid tank 2: Filter material 3: Waste liquid tank 4: Filtrate tank P, P1, P2: Pump.

Claims

1. A method for manufacturing SnS 2 ​ It is characterized in that including: Filtration step, in which a SnS 2 dispersion containing SnS, a solvent, and impurities 2 is passed through a filter medium of a filtration unit to form a SnS 2 aggregate on the filter medium; and A cleaning process, in which a cleaning liquid is passed through the SnS formed on the formed filter material to clean the SnS 2 aggregates 2 aggregates 2. The manufacturing method of SnS according to claim 1 2 ​ wherein, the solvent contains water.

3. The manufacturing method of SnS according to claim 2 2 ​ wherein, the conductivity of the solvent is less than 10 μS / cm.

4. The manufacturing method of SnS according to claim 1 2 ​ wherein, In the vertical direction with respect to the filtration surface of the filtration material, the thickness of the washed SnS 2 aggregates obtained through the cleaning process is 1 mm to 100 mm.

5. The manufacturing method of SnS according to claim 1 2 ​ wherein, the cleaning solution contains water.

6. The manufacturing method of SnS according to claim 5 2 ​ wherein, the conductivity of the cleaning solution is less than 10 μS / cm.

7. The manufacturing method of SnS according to any one of claims 1 to 6 2 ​ wherein, The manufacturing method includes a drying step in which the washed SnS 2 aggregate obtained through the washing step is dried under a pressure of less than 5 kPa.

8. A method of using SnS 2 ​ it is characterized in that including the following steps: bringing SnS produced by the method according to any one of claims 1 to 6 into contact with a sulfide containing an alkali metal to obtain a compound containing an alkali metal, tin and sulfur. 2 ​

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