JP6222072B2 - Electrolytic apparatus for indium hydroxide powder or tin hydroxide powder, method for producing indium hydroxide powder or tin hydroxide powder, and method for producing sputtering target - Google Patents

Description

  The present invention relates to an electrolysis apparatus for indium hydroxide powder or tin hydroxide powder, a method for producing indium hydroxide powder or tin hydroxide powder, and a method for producing a sputtering target. In particular, an indium hydroxide powder or tin hydroxide powder electrolysis apparatus capable of producing indium hydroxide powder or tin hydroxide powder having a narrow particle size distribution, indium hydroxide powder or hydroxide using the electrolysis apparatus The present invention relates to a method for producing tin powder and a method for producing a high-density sputtering target using indium hydroxide powder and / or tin hydroxide powder.

  In recent years, the use of transparent conductive films has been increasing for applications such as solar cells and touch panels, and accordingly, the demand for materials for forming transparent conductive films in sputtering targets and the like has increased. As a material for forming the transparent conductive film, an indium oxide-based sintered material is mainly used, and indium oxide powder is used as a main raw material. The indium oxide powder used for the sputtering target is desirably as narrow as possible in order to obtain a high-density target.

  In the method for producing indium oxide powder, the precipitate of indium hydroxide formed by neutralizing an acidic aqueous solution such as an indium nitrate aqueous solution or an indium chloride aqueous solution with an alkaline aqueous solution such as ammonia water is mainly dried and calcined. Indium oxide powder is obtained by a so-called neutralization method.

  In patent document 1, in order to suppress aggregation of the indium oxide powder obtained by the neutralization method, an alkaline aqueous solution is added to a high-temperature indium nitrate aqueous solution of 70 ° C. to 95 ° C., so that acicular indium hydroxide powder is obtained. The method of obtaining is proposed. In this method, indium oxide powder with little aggregation can be obtained by calcining acicular indium hydroxide.

  However, the indium oxide powder produced by the neutralization method tends to have non-uniform particle size and particle size distribution, and when the sputtering target is produced, the density does not increase and the density varies. There is a problem that abnormal discharge is likely to occur. Moreover, in the neutralization method, after producing indium oxide powder, wastewater containing a large amount of nitrogen is generated, and thus there is a problem that wastewater treatment costs increase.

  As a method for solving such a problem, Patent Document 2 discloses a method of producing indium oxide powder by precipitating indium hydroxide by electrolytically treating metal indium, and so-called electrolytic method. Has been proposed. Patent Document 3 proposes a method of producing tin oxide powder by causing tin hydroxide to precipitate by electrolytic treatment of tin, as in Patent Document 2, and calcining this. Compared with the neutralization method, the electrolytic method can reduce the amount of nitrogen drainage after producing indium oxide powder and tin oxide powder, and also makes the particle size of indium oxide powder and tin oxide powder uniform. be able to.

  However, the indium hydroxide powder obtained using the electrolytic method has a problem that it is very fine and easily aggregates because the pH of the electrolytic solution is close to neutral. Although the indium oxide powder obtained by calcining this has a relatively uniform primary particle diameter, it becomes easy to obtain an agglomerated powder in which these particles are strongly aggregated. Therefore, the indium oxide powder has a problem that the density of the sputtering target is hindered because the particle size distribution is widened by aggregation.

  On the other hand, Patent Document 4 discloses a method of performing electrolysis by stirring in a state in which a precipitate of indium hydroxide is suspended in the electrolytic solution in order to make the pH of the electrolytic solution in the tank uniform in the electrolytic method. Proposed.

  However, Patent Document 4 has a problem in that it is not always easy to control the production conditions such as the liquid temperature and pH as the production time elapses, and the characteristics of the indium hydroxide powder vary. .

  Further, in Patent Document 5, a nozzle is arranged in an electrolytic cell, and an electrolytic solution flowing out from the opening of the nozzle is circulated between each cathode plate and anode plate in the electrolytic cell, and indium hydroxide or indium hydroxide is used. There has been proposed a method of precipitating a compound containing s in an electrolytic solution.

  However, in Patent Document 5, since a high electrolyte supply speed is required to circulate the electrolyte, the environment around the electrolytic apparatus is deteriorated due to volatilization of the electrolyte, scattering of mist, and the like. There is a problem.

  Furthermore, Patent Document 6 proposes that in the electrolytic method, indium hydroxide powder and tin hydroxide powder for obtaining a high-density ITO sputtering target material have a particle size of a predetermined range.

  However, in the electrolytic precipitation step of Patent Document 6, it is difficult to say that a technique for obtaining an electrolytically precipitated powder having a sufficiently uniform particle size is provided.

JP-A-4-325415 JP-A-6-171937 JP-A-6-199523 JP-A-10-204669 JP 2013-36074 A JP-A-5-193939

  Therefore, the present invention has been proposed in view of such circumstances, and it is possible to produce indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution. An object of the present invention is to provide an electrolysis apparatus for indium hydroxide powder or tin hydroxide powder.

  The present invention also provides an indium hydroxide powder or an indium hydroxide powder that can produce indium hydroxide powder or tin hydroxide powder that has excellent particle size uniformity and a narrow particle size distribution by using the above-described electrolysis device. It aims at providing the manufacturing method of tin hydroxide powder.

  Furthermore, this invention provides the manufacturing method of the sputtering target which can manufacture a high-density sputtering target by using the indium hydroxide powder and / or tin hydroxide powder obtained by the above-mentioned manufacturing method. For the purpose.

An electrolysis apparatus for indium hydroxide powder or tin hydroxide powder according to the present invention for achieving the above-described object is an electrolysis apparatus for electrolyzing indium or tin to produce indium hydroxide powder or tin hydroxide powder. An electrolytic tank in which the electrolytic solution is stored and a plurality of electrodes are provided in parallel at a predetermined interval; an adjustment tank that adjusts the electrolytic solution; and a tank wall that is provided near one tank wall. A supply nozzle that jets the electrolyte parallel to the width direction, and a suction nozzle that is provided near the tank wall of the electrolytic cell at a position facing the supply nozzle, and supplies the electrolytic solution from the adjustment tank via the supply nozzle. The electrolyte is jetted in parallel to the electrode width direction toward the adjustment tank, and the electrolyte is sucked through the suction nozzle to form a laminar flow of the electrolyte in a straight line, and the electrolyte is transferred to the adjustment tank. Between the electrolytic cell and the adjustment tank Wherein the circulating electrolyte solution.

In this way, a laminar flow of the electrolytic solution is formed between the electrodes and the electrolytic solution is circulated, so that the composition, concentration, pH, liquid temperature, etc. of the electrolytic solution can be made uniform. Indium hydroxide powder or tin hydroxide powder having excellent particle size distribution and narrow width can be produced. In addition, since the electrolyte is circulated by forming a laminar flow of the electrolyte evenly between the electrodes, indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and narrow particle size distribution is generated. be able to. Furthermore, a laminar flow of the electrolytic solution is formed between the electrodes, and the electrolytic solution is circulated to efficiently and uniformly make the composition, concentration, pH, liquid temperature, etc. of the electrolytic solution near the surface of the electrolytic cell and the bottom of the cell. Therefore, it is possible to produce indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

  In one embodiment of the present invention, the circulation amount of the electrolytic solution for transferring the electrolytic solution from the suction nozzle provided in the electrolytic cell to the adjustment tank is 0.03 L / min / A per electrolytic current 1 A to 0.10 L / electrolytic current 1 A. It is preferable to control to min / A.

  In this way, an increase in pH of the electrolytic solution can be suppressed, and a laminar flow of the electrolytic solution is formed linearly between the electrodes, and the electrolytic solution is circulated, so that the composition, concentration, pH, The liquid temperature can be made uniform. As a result, it is possible to generate indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

  In one aspect of the present invention, in order to overflow the electrolytic solution from the electrolytic bath to the adjusting bath, a drain port is provided at the upper edge of the tank wall on the adjusting bath side of the electrolytic bath, and the electrolytic solution overflows and is adjusted from the drain port. It is preferable that the total supply amount of the electrolytic solution obtained by adding the amount of the electrolytic solution transferred to the tank and the circulating amount of the electrolytic solution is controlled to 110% to 160% with respect to the circulating amount of the electrolytic solution.

  In this way, the electrolytic solution overflowed from the electrolytic cell through the drain port is transferred to the adjusting tank, so that the liquid level of the electrolytic cell is maintained constant so that the electrode is immersed, and the pH and composition of the electrolytic solution are maintained. In addition, the liquid temperature, concentration, and the like can be efficiently suppressed from becoming non-uniform. As a result, indium hydroxide powder or tin hydroxide powder having a uniform particle size and a narrow particle size distribution can be produced.

  In one embodiment of the present invention, the volume ratio of the adjustment tank to the electrolytic tank is preferably 0.1 or more.

  In this way, it is easy to uniformly control the composition, concentration and pH of the electrolytic solution, and it is possible to produce indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution range. .

  The method for producing indium hydroxide powder or tin hydroxide powder according to the present invention comprises producing indium hydroxide powder or tin hydroxide powder by electrolysis using indium or tin as an anode. It is a method, The electrolysis apparatus of the said indium hydroxide powder or tin hydroxide powder is used, It is characterized by the above-mentioned.

  In this way, it is possible to produce indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

In one embodiment of the present invention, when the anode is indium, an aqueous 0.1 mol / L to 2.0 mol / L ammonium nitrate solution is used as the electrolyte, and the pH of the electrolyte is 2.5 to 4.0. the 20 ° C. to 60 ° C., it is preferable and for controlling the electrode current density in the range of ^{4A / dm 2 ~20A / dm 2} .

  In this way, it is possible to control the solubility of the indium hydroxide powder to a suitable level, so that it is possible to produce indium hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

In one embodiment of the present invention, when the anode is tin, 0.1 mol / L to 2.0 mol / L of an ammonium nitrate aqueous solution is used as the electrolyte, and the pH of the electrolyte is 2.5 to 8.0. the 20 ° C. to 60 ° C., it is preferable and for controlling the electrode current density in the range of ^{4A / dm 2 ~20A / dm 2} .

  In this way, it is possible to control the tin hydroxide powder to have a suitable solubility, so that it is possible to produce a tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

  The manufacturing method of the sputtering target which concerns on this invention manufactures a sputtering target using the indium hydroxide powder and / or tin hydroxide powder which were obtained by the manufacturing method of the said indium hydroxide powder or tin hydroxide powder. Features.

  If it does in this way, a high-density sputtering target can be manufactured by using the indium hydroxide powder and / or tin hydroxide powder obtained by the above-mentioned manufacturing method.

  According to the present invention, a laminar flow of the electrolytic solution is formed between the electrodes, the electrolytic solution is circulated, and the composition, concentration, pH, liquid temperature, etc. of the electrolytic solution can be made uniform. Indium hydroxide powder or tin hydroxide powder having a narrow particle size distribution can be obtained. In addition, according to the present invention, a sintered body having a high relative density can be obtained by using indium hydroxide powder and / or tin hydroxide powder having excellent particle size uniformity and narrow particle size distribution. . And according to this invention, it becomes finally possible to manufacture a high-density sputtering target with a sintered compact with a high relative density.

1 is a schematic view of an electrolysis apparatus showing an embodiment of an electrolysis apparatus according to the present invention. It is XX 'sectional drawing which shows the outline of the state which has arrange | positioned the electrode and the circulation means in the electrolytic cell of the electrolysis apparatus shown in FIG. It is the schematic which showed typically the nozzle contained in the circulation means in the electrolytic vessel of the electrolytic device shown in FIG.

  A specific embodiment to which the present invention is applied (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings in the following order. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

1. 1. Indium hydroxide powder or tin hydroxide powder electrolyzer 1-1. Electrolytic cell 1-2. Adjustment tank 1-3. Circulation means 2. Method for producing indium hydroxide powder or tin hydroxide powder 2-1. Electrolysis process 2-2. Electrolyte separation process 2-3. Repulp washing process 2-4. Cleaning liquid dehydration step 2-5. 2. Drying process 3. Production method of indium oxide powder or tin oxide powder Manufacturing method of sputtering target

[1. Indium hydroxide powder or tin hydroxide powder electrolyzer]
First, an electrolysis apparatus for indium hydroxide powder or tin hydroxide powder according to the present embodiment will be described. As shown in FIG. 1, the electrolysis apparatus 1 includes an electrolysis tank 10, an adjustment tank 20, and a circulation means 30 that circulates the electrolyte solution 11 between the electrolysis tank 10 and the adjustment tank 20. The circulation means 30 includes a supply channel 33 for supplying the electrolyte solution 11 from the adjustment tank 20 via the supply pump 31 and the supply nozzle 32, and the adjustment tank 20 from the electrolyte tank 10 via the suction pump 35 via the suction nozzle 34. A suction channel 36 for transferring the electrolyte solution 11 is provided.

  The electrolytic device 1 supplies the electrolytic solution 11 into the electrolytic cell 10 by feeding the electrolytic solution 11 in the adjustment tank 20 to the supply flow path 33 by the pressure of the supply pump 31 and discharging it from the supply nozzle 32. be able to. When the electrolytic solution 11 is continuously supplied into the electrolytic cell 10, the electrolytic solution 11 in the electrolytic cell 10 is discharged from the suction nozzle 34 to the adjustment tank 20 by the pressure of the suction pump 35. It becomes possible to circulate the electrolytic solution 11 between the electrolytic cell 10 and the adjusting cell 20.

  In the electrolysis apparatus 1 shown in FIG. 1, the electrolysis tank 10 and the adjustment tank 20 are integrated to form one tank, which is the indium hydroxide powder or water according to the present embodiment. It is only one embodiment of the tin oxide powder electrolysis apparatus 1. For example, the electrolytic bath 10 and the regulating bath 20 are separate, and the electrolytic solution 11 can be sucked from the electrolytic bath 10 through the suction nozzle 34 and transferred to the regulating bath 20 by the suction pump 35. It can also be set as the electrolysis apparatus 1 which made the electrolytic vessel 10 and the adjustment tank 20 adjoin.

<1-1. Electrolyzer>
Next, the electrolytic cell 10 will be described. As shown in FIG. 2, the electrolytic cell 10 has a plurality of anodes (anodes) 12 and cathodes (cathodes) 13 disposed therein. The anode 12 and the cathode 13 are arranged vertically on the tank bottom 14 of the electrolytic cell 10, and a conductive wire 15a (for example, a 2-core VV cable, “JIS C 3342”, allowable current 200A, nominal cross-sectional area 100 mm ² ). By using and connecting, it can connect with the rectifier which is not illustrated. Further, the cathodes 13 are electrically connected to each other by a conducting wire 15b. An insertion port 16 is provided in the tank bottom 14 of the electrolytic cell 10 so as to allow the supply flow path 33 to be inserted. As illustrated in FIG. 1, the tank wall 17 b on the adjustment tank 20 side of the electrolytic cell 10 includes A drain port 18 serving as a flow path when the electrolyte solution 11 overflows is provided.

  The shape of the electrolytic cell 10 is not particularly limited, and a general rectangular parallelepiped, a cube such as a cube can be applied, and is appropriately determined in consideration of the number and size of electrodes and the like arranged in the cell. . The shape of the four corners of the electrolytic cell 10 is preferably rounded, for example, so that indium hydroxide powder or tin hydroxide powder can flow and local deposition does not occur.

  The material of the electrolytic cell 10 may be any material that does not dissolve in the electrolytic solution 11 and has heat resistance equal to or higher than the liquid temperature of the electrolytic solution 11 during electrolysis, such as PVC (polyvinyl chloride), PP (polypropylene), stainless steel, titanium, etc. Can be used.

  For the anode 12, for example, metal indium, metal tin, or the like is used. Metal indium, metal tin, etc. to be used are not particularly limited, but it suppresses mixing of impurities into indium hydroxide powder or tin hydroxide powder, or indium oxide powder or tin oxide powder obtained by firing each hydroxide powder. Therefore, high purity is desirable. As metal indium or metal tin, a purity of 99.9999% (commonly called 6N product) can be mentioned as a suitable product.

  The thickness of the anode 12 is preferably set to such an extent that the distance between the electrodes does not change remarkably during the electrolysis time. The size of the anode 12 may be appropriately determined according to the production scale or in accordance with the target production amount.

  As the cathode 13, a conductive metal, a carbon electrode, or the like is used. For example, insoluble titanium, stainless steel, or platinum can be used, and titanium can be coated with platinum, and the same material as the anode 12 can be used. May be used. The thickness of the cathode 13 can be appropriately changed according to the size of the electrolysis apparatus 1 and the like, and the size of the cathode 13 can be appropriately determined according to the production scale or according to the target production amount. Good.

  The distance between the electrodes of the anode 12 and the cathode 13 is not particularly specified, but is preferably 10 mm to 50 mm. If the distance between the electrodes is larger than 50 mm, a voltage drop due to the resistance of the electrolytic solution 11 occurs, which causes an increase in the liquid temperature, which is not preferable. On the other hand, if the distance between the electrodes is smaller than 10 mm, it is not preferable because contact or short-circuit between the electrodes tends to occur. Therefore, the distance between the electrodes of the anode 12 and the cathode 13 is preferably 10 mm to 50 mm.

  The arrangement of the anode 12 and the cathode 13 is not particularly limited, and a general arrangement of electrodes can be adopted. For example, in the electrolysis apparatus 1, it is preferable to arrange | position alternately so that both poles may become mutually parallel.

  The insertion port 16 is provided in the tank bottom 14 of the electrolytic cell 10 in the vicinity of the tank wall 17a on the side opposite to the adjustment tank 20. However, the position at which the insertion port 16 is disposed in the tank bottom 14 can be appropriately changed according to the installation status of the circulation means 30 described later. The shape of the insertion port 16 can be appropriately changed according to the shape of the supply flow path 33 to be inserted, and can be, for example, circular or elliptical.

  The drain port 18 is the entire upper end edge of the tank wall 17 b on the adjustment tank 20 side of the electrolytic tank 10. That is, when the upper end edge of the tank wall 17 b becomes the drain port 18, the electrolyte solution 11 can get over the upper end edge of the tank wall 17 b and overflow the electrolyte solution 11 from the electrolytic tank 10 to the adjustment tank 20. In the electrolysis apparatus 1, by providing the drain port 18, a flow rate balance between a supply pump 31 and a suction pump 35 described later can be maintained, and the problem that the liquid level of the electrolytic solution 11 in the electrolytic cell 10 rises and falls does not occur. .

  The drain port 18 may be provided by cutting out a part of the tank wall 17b at the center of the upper edge of the tank wall 17b on the adjustment tank 20 side of the electrolytic cell 10. With this configuration, the electrolytic solution 11 can flow from the electrolytic cell 10 to the adjusting tank 20 and overflow from the cutout portion. The drain port 18 provided by cutting out can stabilize the amount of the electrolytic solution 11 flowing compared to the case of overflowing from the entire upper edge of the tank wall 17b. Note that the shape of the cutout portion is not particularly limited as long as the electrolyte solution 11 can overflow, and can be, for example, a square shape such as a U shape, a semicircle, a semielliptical shape, and a rectangular shape.

<1-2. Adjustment tank>
Next, the adjustment tank 20 will be described. As shown in FIG. 1, the adjustment tank 20 stores the electrolyte solution 11 in the tank, and further, a stirring rod 21 for stirring the electrolyte solution 11, a pH electrode 22 for measuring the pH of the electrolyte solution 11, A heater 23 and a cooler 24 that control and maintain the liquid temperature of the electrolytic solution 11, a chemical solution tank 25 that controls and maintains the pH of the electrolytic solution 11, and a metering pump 26 for adding a chemical solution are provided. Further, the tank bottom 27 of the adjustment tank 20 is provided with a liquid supply port 28 for supplying the electrolyte solution 11 from the adjustment tank 20 to the supply flow path 33.

  The shape of the adjustment tank 20 is not particularly limited, and a general rectangular parallelepiped, a cube such as a cube can be applied, and is determined as appropriate in consideration of the number and size of various devices arranged in the tank. The Moreover, it is preferable that the corners of the adjustment tank 20 have rounded corners, for example, so that the electrolyte solution 11 can flow and local uneven distribution such as pH and solution temperature of the electrolyte solution 11 does not occur.

  As for the adjustment tank 20, it is preferable that the volume ratio of the adjustment tank 20 with respect to the electrolytic cell 10 is 0.1 or more, and it is more preferable that the volume ratio is 1 or more. When the volume ratio of the adjusting tank 20 to the electrolytic tank 10 is less than 0.1, it is difficult to uniformly control the pH and temperature of the electrolytic solution 11, and the particle size distribution of the indium hydroxide powder or tin hydroxide powder is difficult. Since the width is wide, it is not preferable.

  In the adjustment tank 20, the charged electrolytic solution 11 is stirred by the stirring rod 21, and the pH, liquid temperature, and the like of the electrolytic solution 11 can be made uniform. At this time, the pH value of the electrolytic solution 11 in the adjustment tank 20 is measured by the pH electrode 22, and the measured pH value is fed back and adjusted to a predetermined value by the chemical solution tank 25 and the metering pump 26. The In the adjustment tank 20, the addition amount of the pH adjusting agent in the chemical solution tank 25 is adjusted by the pressure of the metering pump 26 so that the electrolyte solution 11 has a predetermined pH value. As a result, in the adjustment tank 20, the electrolyte solution 11 can be controlled and maintained at a predetermined pH value. Here, for example, 1N nitric acid or the like can be used as the pH adjuster.

  Moreover, the liquid temperature of the electrolyte solution 11 in the adjustment tank 20 is measured by a thermometer (not shown), and the measured liquid temperature is fed back and adjusted to a predetermined temperature by the heater 23 and the cooler 24. . In the adjustment tank 20, the temperature of the electrolytic solution 11 can be controlled and maintained by heating or cooling the electrolytic solution 11 with the heater 23 and the cooler 24.

  The liquid feeding port 28 is provided at the center of the tank bottom 27 of the adjustment tank 20. However, the position at which the liquid feeding port 28 is disposed on the tank bottom 27 can be changed as appropriate according to the installation status of the electrolysis apparatus 1. For example, the position at which the liquid feeding port 28 is disposed at the insertion port 16. It can be changed as appropriate according to the situation. The shape of the liquid feeding port 28 can be appropriately changed according to the shape of one tip of the supply flow path 33 to be connected, and can be, for example, circular or elliptical.

<1-3. Circulation means>
As shown in FIGS. 1 and 2, the circulation means 30 includes a supply channel 33 connected from the adjustment tank 20 to the electrolytic cell 10, a supply pump 31 provided in the supply channel 33, and a supply channel 33. A liquid supply pipe 37 connected to be provided with a plurality of supply nozzles 32, a suction flow path 36 connected from the electrolytic cell 10 to the adjustment tank 20, a suction pump 35 provided in the suction flow path 36, and a suction flow path 36 A suction pipe that is connected and provided with a plurality of suction nozzles 34 and a transfer port 38 that transfers the electrolyte solution 11 sucked from the suction nozzles 34 into the adjustment tank 20 are provided.

  The supply flow path 33 is a pipe for supplying the electrolytic solution 11 stored in the adjustment tank 20 to the electrolytic tank 10, and is made of a material that is not corroded by the electrolytic solution 11. The supply flow path 33 is provided on the lower side of the electrolysis apparatus 1, and one end thereof is connected to a liquid supply port 28 installed on the tank bottom 27 of the adjustment tank 20.

  The supply flow path 33 is inserted into the insertion port 16 provided in the tank bottom 14 of the electrolytic cell 10, and the length is adjusted so that the other end portion is not exposed from the liquid surface of the electrolytic solution 11. A plurality of liquid supply pipes 37 are connected to the supply flow path 33 in the electrolytic cell 10. Note that the installation position of the supply flow path 33 depends on the installation status of the electrolysis apparatus 1, for example, when the insertion port 16 is provided in any of the tank walls 17 b to 17 d of the electrolysis tank 10. Other than the lower side of 1 can be changed as appropriate.

  The supply pump 31 feeds the electrolytic solution 11 whose pH, liquid temperature, and the like are adjusted in the adjustment tank 20 from the liquid feed port 28 to the supply flow path 33 by adjusting the pressure of the supply pump 31. The liquid is supplied into the electrolytic cell 10 from the supply nozzle 32 through the pipe 37.

  In the present embodiment, a plurality of supply nozzles 32 are provided in the electrolytic cell 10 at a predetermined interval between at least the electrodes. Specifically, the plurality of supply nozzles 32 are respectively provided in the liquid supply pipe 37 so as to be positioned between the electrodes and the tank wall 17 b of the electrolytic cell 10 and inserted between the electrodes A. Further, the plurality of supply nozzles 32 are located between the electrode and the tank wall 17 b of the electrolytic cell 10 and are inserted into gaps B and C between the electrode and the two tank walls 17 c and 17 d in the longitudinal direction of the electrolytic cell 10. In addition, the liquid supply pipe 37 may be provided.

  With this configuration, the circulation means 30 can reliably supply the electrolytic solution 11 discharged from the supply nozzle 32 to the interelectrode A and the gaps B and C in the electrolytic cell 10. Furthermore, in the circulation means 30, by disposing the supply nozzle 32 as described above, it is unidirectional, that is, linear (from the tank wall 17a side of the electrolytic cell 10 to the adjustment tank 20 side (the electrolytic cell 10 shown in FIG. 1). The laminar flow of the electrolytic solution 11 can be formed in the direction of the arrow in the figure, and the electrolytic solution 11 can be fed. That is, in the circulation means 30, the electrolytic solution 11 is jetted from the supply nozzle 32 toward the adjustment tank 20 into the interelectrode A and the gaps B and C.

  Therefore, in the circulation means 30, the electrolytic solution 11 flows from the tank wall 17 a side of the electrolytic cell 10 toward the adjustment tank 20 side, for example, toward the liquid surface of the electrolytic solution 11, with the configuration as described above. Therefore, the straightness of the electrolytic solution 11 can be ensured. Furthermore, in the electrolysis apparatus 1, since the jet of the electrolyte solution 11 does not flow in the direction of the liquid surface of the electrolyte solution 11, volatilization of the electrolyte solution 11, scattering of mist, and the like can be suppressed. It is possible to prevent the deterioration of the surrounding environment and ensure safety.

  Further, in the circulation means 30, as described above, the plurality of supply nozzles 32 are provided in the liquid supply pipe 37, respectively, so that the jet of the electrolyte solution 11 can flow through all the electrodes A and the gaps B and C. it can. With this configuration, in the circulation means 30, compared with the case where the supply nozzle 32 is used alone, the electrolytic solution 11 in the entire electrolytic cell 10 is transferred to the tank wall 17 a of the electrolytic cell 10 without applying a load to the supply pump 31. The liquid can be fed in one direction from the side toward the adjustment tank 20 side.

  In the circulation means 30, the shape of the supply nozzle 32 is not particularly limited, but the shape and diameter of the outlet of the supply nozzle 32 are necessary as necessary in order to ensure straightness and speed of the jet of the electrolyte solution 11. It is preferable to adjust dimensions and the like. The jet velocity of the electrolytic solution 11 can be controlled by the supply amount of the electrolytic solution 11 and the water flow. In other words, the circulation means 30 can control the jet velocity of the electrolyte solution 11 by adjusting the supply amount of the electrolyte solution 11 by the supply pump 31 and appropriately changing the supply nozzle inner diameter D (see FIG. 3). .

  The supply amount of the electrolyte solution 11 discharged from the supply nozzle 32 should be larger than the circulation amount for sucking the electrolyte solution 11 from the suction nozzle 34 of the electrolytic cell 10 to such an extent that the liquid level of the electrolytic cell 10 can be maintained constant. It is not limited. The circulation amount is the amount of electrolyte solution for transferring the electrolyte solution 11 from the suction nozzle 34 provided in the vicinity of the tank wall 17b on the adjustment tank 20 side of the electrolytic tank 10 to the adjustment tank 20 (hereinafter also referred to as “circulation amount”). .)

  For example, as shown in FIG. 3, the supply nozzle 32 preferably has a protruding tube configured with a predetermined supply nozzle inner diameter D and a supply nozzle length L. In the protruding tube of the supply nozzle 32, the supply nozzle inner diameter D is preferably 3 mm or more, particularly preferably 5 mm to 10 mm, and the supply nozzle length L is preferably 3 mm to 20 mm.

  The supply nozzles 32 are preferably provided in multiple stages at predetermined intervals in the vertical direction of the electrodes. With this configuration, the jet of the electrolyte solution 11 formed as described above is discharged from the supply nozzles 32 arranged at predetermined intervals in the vertical direction of the electrodes, and they are all provided on the adjustment tank 20 side. By flowing toward the nozzle 34, a laminar flow of the electrolytic solution 11 is uniformly formed between the electrodes, and the electrolytic solution 11 is circulated. For this reason, the composition, concentration, pH, liquid temperature, etc. of the liquid surface in the electrolytic cell 10 and the vicinity of the cell bottom 14 can be made uniform, so that the particle size distribution is excellent and the particle size distribution is wide. Can produce narrow indium hydroxide powder or tin hydroxide powder.

  That is, in the circulation means 30, the laminar flow of the formed electrolyte solution 11 flows between the electrodes A and the gaps B and C. Therefore, the stagnation of the electrolyte solution 11 between the electrodes A and the gaps B and C is eliminated, and the electrolytic cell The electrolyte solution 11 in 10 can be made uniform, and the width of the particle size distribution of the generated indium hydroxide powder or tin hydroxide powder can be suppressed. Here, the homogenization of the electrolytic solution 11 means that the composition, concentration, pH, liquid temperature, and the like of the electrolytic solution 11 are substantially the same in the interelectrode A and the gaps B and C.

  In addition, in the electrolysis apparatus 1, if at least the electrolyte solution 11 in the interelectrode A is made uniform, the electrolyte solution 11 in the electrolytic cell 10 can be made uniform, and the generated indium hydroxide powder or tin hydroxide is produced. Since the spread of the width of the particle size distribution of the powder can be suppressed, the supply nozzle 32 is located between the electrode and the tank walls 17c and 17d of the electrolytic cell 10 and is positioned so as to be inserted between the electrodes A. What is necessary is just to be provided in the liquid pipe 37, respectively.

  The number of supply nozzles 32 is appropriately changed according to the number of anodes 12 and cathodes 13 to be installed, the size of the electrolytic cell 10, and the like, and is not particularly limited.

  The liquid supply pipe 37 is a pipe for supplying the electrolytic solution 11 fed from the adjustment tank 20 through the supply flow path 33 into the electrolytic tank 10 and is made of a material that is not corroded by the electrolytic solution 11. is there. In the electrolytic cell 10, a plurality of liquid supply pipes 37 are arranged in multiple stages at predetermined intervals in the width direction of the electrodes, and one end of the liquid supply pipe 37 is connected to the supply flow path 33. ing. With this configuration, the electrolytic device 1 can supply the electrolytic solution 11 fed from the adjustment tank 20 through the supply flow path 33 into the electrolytic tank 10 through the supply nozzle 32.

  The suction channel 36 is a pipe for transferring the electrolytic solution 11 sucked from the electrolytic bath 10 by the suction nozzle 34 to the adjustment bath 20 and is made of a material that is not corroded by the electrolytic solution 11. The suction channel 36 is provided on the upper side of the electrolysis apparatus 1, and a transfer port 38 is provided at one end of the suction channel 36 in the upper center of the adjustment tank 20.

  The suction pump 35 sends the electrolyte 11 in the tank from the suction nozzle 34 to the suction flow path 36 by adjusting the pressure of the suction pump 35 by supplying the electrolyte 11 supplied from the supply nozzle 32 to the electrolytic tank 10. , It is returned from the transfer port 38 into the adjusting tank 20.

  The suction nozzle 34 is provided in the vicinity of the tank wall 17b on the adjustment tank 20 side of the electrolytic cell 10 facing the vicinity of the tank wall 17a of the electrolytic cell 10 in which the supply nozzle 32 is provided. As a result, the suction nozzle 34 is provided in the vicinity of the tank wall 17b of the electrolytic cell 10 at a position facing the supply nozzle 32, so that the electrolytic solution 11 is supplied from the supply nozzle 32 and the supplied electrolytic solution 11 is sucked. Since suction is performed from the nozzle 34, a laminar flow stable in one direction can be formed.

  In the circulation means 30, the shape of the suction nozzle 34 is not particularly limited. However, in order to ensure the straightness and speed of the jet of the electrolyte solution 11 supplied from the supply nozzle 32, the suction nozzle 34 is used as necessary. It is preferable to adjust the shape and diameter of the suction port. The suction speed of the electrolytic solution 11 can be controlled by the circulation amount of the electrolytic solution. That is, in the circulation means 30, the suction speed of the electrolyte solution 11 can be controlled by adjusting the circulation amount of the electrolyte solution by the suction pump 35 and appropriately changing the suction nozzle inner diameter.

  For example, the suction nozzle 34 preferably has a protruding tube having a predetermined suction nozzle inner diameter and a suction nozzle length. In the protruding tube of the suction nozzle 34, the suction nozzle inner diameter is preferably 3 mm or more, particularly preferably 5 mm to 10 mm, and the suction nozzle length is preferably 3 mm to 20 mm.

  Here, the suction nozzles 34 are preferably provided in multiple stages at predetermined intervals in the vertical direction of the electrodes. With this configuration, the electrolytic solution 11 in the electrolytic cell 10 can be adjusted to the adjusting tank 20 by sucking the electrolytic solution 11 in the vicinity of the liquid surface and bottom of the electrolytic cell 10 with the suction nozzle 34. The composition, concentration, pH, liquid temperature, and the like of the electrolytic solution 11 near the surface and bottom can be made uniform. As a result, it is possible to generate indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution. The suction nozzle 34 may be provided in each suction pipe (not shown) so as to be positioned between the electrode and the tank walls 17c and 17d of the electrolytic cell 10 and inserted between the electrodes A.

  The number of suction nozzles 34 is appropriately changed according to the number of anodes 12 and cathodes 13 to be installed, the size of the electrolytic cell 10, and the like, and is not particularly limited.

  The suction pipe is a pipe for transferring the electrolytic solution 11 sucked from the electrolytic bath 10 through the suction flow path 36 into the adjusting bath 20 and is made of a material that is not corroded by the electrolytic solution 11. In the electrolytic cell 10, a plurality of suction pipes are arranged in multiple stages at predetermined intervals in the height direction of the electrodes, and one tip of the suction pipe is connected to the suction flow path 36. With this configuration, in the electrolysis apparatus 1, the electrolytic solution 11 sucked from the electrolytic cell 10 through the suction flow path 36 can be transferred into the adjustment tank 20 through the transfer port 38, and the suction nozzle 34. Are arranged in multiple stages at predetermined intervals in the width direction of the electrodes.

  A suction flow path 36 is disposed on the upper side of the electrolysis apparatus 1, and a transfer port 38 provided at one end of the suction flow path 36 is provided at the upper center of the adjustment tank 20. However, the position at which the transfer port 38 is disposed can be appropriately changed according to the installation state of the electrolysis apparatus 1. For example, the transfer port 38 is appropriately changed according to the position at which the suction flow path 36 is disposed. can do. The shape of the transfer port 38 can be appropriately changed according to the shape or the like of one tip of the suction channel 36 to be connected, and can be, for example, circular or elliptical.

  In the electrolytic cell 10, the electrolytic solution 11 is supplied from the supply nozzle 32, and the suction nozzle 34 is provided in the vicinity of the tank wall 17 b on the adjustment tank 20 side of the electrolytic cell 10, so that a laminar flow is ensured because a linear flow can be promoted. can do. By forming a laminar flow between the electrodes, the stagnation of the electrolytic solution 11 is eliminated, and the pH, concentration, composition, and the like of the electrolytic solution 11 in the electrolytic cell 10 are made uniform. In the case where the electrolytic solution 11 is not circulated, for example, the liquid temperature and pH are non-uniform in the vicinity of the liquid surface of the electrolytic cell 10 and the vicinity of the cell bottom 14 with the energization time. Not only that, even if the generated hydroxide precipitate particles quickly diffuse through the electrolytic cell 10 and move to the adjusting cell 20 to adjust the liquid temperature and pH of the electrolytic solution 11, extremely heterogeneous hydroxylation. Indium powder or tin hydroxide powder is generated.

  The circulation amount of the electrolytic solution for transferring the electrolytic solution 11 from the suction nozzle 34 provided in the vicinity of the tank wall 17b on the adjustment tank 20 side of the electrolytic tank 10 to the adjustment tank 20 is 0.03 L / min / A to electrolysis per 1 A of electrolytic current. It is preferable that the current is controlled to 0.10 L / min / A per 1 A of current. Thereby, an increase in pH of the electrolytic solution 11 can be suppressed, and a laminar flow of the electrolytic solution 11 is formed linearly between the electrodes, and the electrolytic solution 11 is circulated. Therefore, the composition, concentration, and pH of the electrolytic solution 11 The liquid temperature can be made uniform. For this reason, it is possible to generate indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

  When the circulating amount of the electrolytic solution is less than 0.03 L / min / A per 1 A of electrolytic current, the pH around the electrode rises, and the circulating amount is too small. Indium powder or tin hydroxide powder aggregates. As a result, indium hydroxide powder or tin hydroxide powder with a uniform particle size and a narrow particle size distribution cannot be produced. On the other hand, when the circulation amount of the electrolytic solution 11 exceeds 0.10 L / min / A per electrolytic current, the amount of the electrolytic solution 11 supplied from the adjustment tank 20 to the electrolytic tank 10 is insufficient, and the electrolysis is stopped. I have to do it. Therefore, the circulation amount of the electrolytic solution is preferably controlled to 0.03 L / min / A per electrolytic current 1 A to 0.10 L / min / A per electrolytic current 1 A.

  The total amount of the electrolytic solution in which the electrolytic solution 11 overflows from the drain port 18 provided at the upper end edge of the tank wall 17b on the adjustment tank 20 side of the electrolytic tank 10 and is transferred to the adjustment tank 20 and the circulation amount of the electrolytic solution The liquid supply amount (hereinafter also referred to as “total liquid supply amount”) is preferably controlled to 110% to 160% with respect to the circulation amount of the electrolytic solution. As a result, the overflowed electrolytic solution 11 can be transferred to the adjustment tank 20, and the electrolytic solution 11 overflowed from the electrolytic tank 10 is not wasted at all, and the liquid level of the electrolytic solution 11 in the electrolytic tank 10 is constant. Can be maintained. Specifically, the constant height of the liquid surface of the electrolytic solution 11 is a height that is several cm higher than the upper end of the electrode installed in the electrolytic cell 10 and is immersed in the electrode.

  In this way, the electrolytic solution 11 overflowed from the electrolytic cell 10 through the drain port 18 is transferred to the adjustment tank 20, so that the liquid level of the electrolytic solution 11 in the electrolytic cell 10 is kept constant so that the electrode is immersed. In addition, it is possible to efficiently suppress non-uniformity in pH, composition, liquid temperature, concentration, and the like of the electrolytic solution. As a result, indium hydroxide powder or tin hydroxide powder having a uniform particle size and a narrow particle size distribution can be produced.

  When the total amount of electrolyte supplied is less than 110% with respect to the amount of electrolyte circulated, the level of the electrolyte 11 in the electrolytic cell 10 decreases, and electrolysis must be stopped. . On the other hand, when the total amount of electrolyte supplied exceeds 160% of the amount of electrolyte circulated, the electrolyte 11 overflows from the electrolytic cell 10 to other than the adjusting tank 20, and electrolysis must be stopped. I don't get it. Therefore, it is preferable that the total supply amount of the electrolytic solution is controlled to 110% to 160% with respect to the circulating amount of the electrolytic solution.

  As described above, the electrolysis apparatus 1 of indium hydroxide powder or tin hydroxide powder supplies the electrolytic solution 11 from the adjustment tank 20 via the supply nozzle 32 and the width direction of the electrode toward the adjustment tank 20 side. The electrolyte solution 11 is circulated between the electrolyte tank 10 and the adjustment tank 20 by jetting the electrolyte solution 11 in parallel and sucking the electrolyte solution 11 through the suction nozzle 34 and transferring it to the adjustment tank 20. Since a laminar flow of the electrolytic solution 11 is formed in parallel with the width direction between the electrodes and the electrolytic solution 11 is circulated, the composition, concentration, pH, liquid temperature, etc. of the electrolytic solution 11 of the entire electrolytic device 1 are made uniform. be able to. As a result, by making the electrolyte solution 11 uniform, it is possible to produce indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution.

  Moreover, in the electrolysis apparatus 1, since the electrolyte solution 11 can be jetted in parallel with the electrode from the supply nozzle 32 toward the adjustment tank 20, the volatilization of the electrolyte solution 11 and the scattering of mist can be suppressed. It is possible to prevent the surrounding environment in the electrolysis apparatus 1 from deteriorating and ensure safety.

  Further, in the electrolysis apparatus 1, the above-described jet of the electrolyte solution 11 is formed as a laminar flow in the interelectrode A and the gaps B and C between the electrode and the electrolytic cell wall by the supply nozzles 32 provided in a plurality of stages in the circulation means 30. Since it can be supplied, stagnation of the electrolytic solution in the interelectrode A and in the gaps B and C between the electrode and the electrolytic cell wall is eliminated, the electrolytic solution 11 in the electrolytic cell 10 is made uniform, and the generated hydroxide The spread of the particle size distribution of indium powder or tin hydroxide powder can be suppressed.

[2. Method for producing indium hydroxide powder or tin hydroxide powder]
In the method for producing indium hydroxide powder or tin hydroxide powder according to the present embodiment (hereinafter also simply referred to as “hydroxide production method”), the indium hydroxide powder or tin hydroxide powder as described above is used. By using an electrolysis apparatus, an indium hydroxide powder or a tin hydroxide powder is obtained using an electrolysis method. Here, the case where the electrolysis apparatus 1 shown in FIG. 1 is used will be described as an example.

  The method for producing hydroxide includes an electrolysis step for obtaining an electrolytic solution 11 containing indium hydroxide powder or tin hydroxide powder (hereinafter also referred to as “electrolytic slurry”), and solid-liquid separation of the electrolytic solution 11 from the electrolytic slurry. An electrolytic solution separating step, an electrolytic slurry 11 is added to the electrolytic slurry to perform repulp washing, and a washing slurry is obtained, and the washing solution is dehydrated from the obtained washing slurry to obtain indium hydroxide powder or tin hydroxide powder. A cleaning liquid dehydration step to be obtained, and a drying step of drying the obtained indium hydroxide powder or tin hydroxide powder. Hereinafter, details of each step will be described.

<2-1. Electrolysis process>
In the electrolysis process, metal indium or metal tin is used as the anode (anode) 12, a conductive metal or carbon electrode is used as the counter electrode (cathode) 13, and the anode 12 and the cathode 13 are immersed in the electrolyte solution 11. Then, a potential difference is generated between the two electrodes to generate an electric current, whereby the anode 12 is dissolved, and indium hydroxide powder or tin hydroxide powder is crystallized to generate an electrolytic slurry.

(Electrolyte)
As the electrolytic solution 11, an aqueous solution of a general electrolyte salt such as a water-soluble nitrate, sulfate, or chloride salt can be used. Among them, ammonium nitrate is preferable in the electrolysis process. Ammonium nitrate is produced after precipitation of indium hydroxide powder or tin hydroxide powder, and after calcination, nitrate ions and ammonium ions are removed as nitrogen compounds and do not remain as impurities, and indium hydroxide powder or tin hydroxide is produced. The purity of the powder can be increased and the cost can be reduced.

In the electrolysis step, it is preferable to adjust the electrolytic solution 11 so that the solubility of the generated indium hydroxide powder or tin hydroxide powder becomes 10 ⁻⁶ mol / L to 10 ⁻³ mol / L. In the electrolysis process, the solubility of the generated indium hydroxide powder or tin hydroxide powder is in the range of 10 ⁻⁶ mol / L to 10 ⁻³ mol / L, so that the indium hydroxide powder or the hydroxide is appropriately Growth of primary particles of tin powder is promoted. Thereby, in the electrolysis step, aggregation of primary particles is suppressed, so that the width of the particle size distribution is not wide, the width of the particle size distribution is narrow, and an indium hydroxide powder or tin hydroxide powder having a uniform particle size is obtained. be able to.

When the solubility of the indium hydroxide powder or the tin hydroxide powder is less than 10 ⁻⁶ mol / L, the metal ions dissolved from the anode 12 are likely to be nucleated, so that the primary particle diameter becomes too fine. In that case, it becomes difficult to separate and recover the subsequent indium hydroxide powder or tin hydroxide powder.

On the other hand, when the solubility of indium hydroxide powder or tin hydroxide powder exceeds 10 ⁻³ mol / L, the primary particle diameter increases due to the promotion of particle growth. The difference in particle size between particles that do not become large. Since the difference in particle size affects the degree of aggregation, as a result, the width of the particle size distribution of indium hydroxide powder or tin hydroxide powder becomes wide. When the width of the particle size distribution of the indium hydroxide powder or tin hydroxide powder becomes wider, the width of the particle size distribution of the indium oxide powder or tin oxide powder obtained by calcining these becomes wider and is obtained by sintering this. A sputtering target is not preferred because it is difficult to achieve a high density.

Therefore, the electrolyte solution 11 preferably has a solubility of indium hydroxide powder or tin hydroxide powder in the range of 10 ⁻⁶ mol / L to 10 ⁻³ mol / L, and is hydroxylated depending on the concentration, pH, liquid temperature, etc. of the aqueous ammonium nitrate solution. The solubility of indium powder or tin hydroxide powder can be controlled. Thus, since it can control to the suitable solubility of an indium hydroxide powder or a tin hydroxide powder, the indium hydroxide powder or the tin hydroxide powder with a uniform particle size and a narrow particle size distribution width can be obtained.

  The concentration of the electrolytic solution 11 is preferably adjusted to 0.1 mol / L to 2.0 mol / L. When the concentration of the electrolytic solution 11 is less than 0.1 mol / L, a voltage increase during electrolysis is increased, and problems such as heating of the energizing part and an increase in power cost are not preferable. On the other hand, when the concentration of the electrolytic solution 11 exceeds 2.0 mol / L, indium hydroxide particles or tin hydroxide particles are coarsened by electrolysis and the variation in particle size becomes large, which is not preferable.

  In the electrolysis step, when obtaining indium hydroxide powder, it is preferable to adjust the pH of the electrolytic solution 11 to 2.5 to 4.0. When the pH of the electrolytic solution 11 is less than 2.5, indium hydroxide powder does not precipitate. On the other hand, when the pH of the electrolytic solution 11 exceeds 4.0, the precipitation of the indium hydroxide powder is too fast and a precipitate is formed while the concentration of the electrolytic solution 11 is not uniform. The width of the distribution becomes wide, and the width of the particle size distribution of the indium hydroxide powder cannot be controlled to be small.

  In the electrolysis step, when obtaining tin hydroxide powder, the pH of the electrolytic solution 11 is preferably adjusted to 2.5 to 8.0. When the pH of the electrolytic solution 11 is less than 2.5, precipitation of tin hydroxide powder does not occur. On the other hand, when the pH of the electrolytic solution 11 exceeds 8.0, the precipitation of the tin hydroxide powder is too fast and the precipitate is formed with the concentration of the electrolytic solution 11 being non-uniform. The width of the distribution becomes wide, and the width of the particle size distribution of the tin hydroxide powder cannot be controlled to be small.

  The liquid temperature of the electrolytic solution 11 is preferably adjusted to 20 ° C to 60 ° C. When the liquid temperature of the electrolyte solution 11 is less than 20 ° C., the precipitation of indium hydroxide powder or tin hydroxide powder is too slow. On the other hand, when the liquid temperature of the electrolytic solution 11 exceeds 60 ° C., indium hydroxide powder or tin hydroxide powder is deposited too quickly, so that the precipitate is formed while the concentration of the electrolytic solution 11 is not uniform. The width of the particle size distribution of indium hydroxide powder or tin hydroxide powder is widened.

(Current density)
Current density during electrolysis ^is preferably adjusted to ^{4A / dm 2 ~20A / dm 2} . As a result, a wide range of current densities can be obtained. When the current density during electrolysis is less than 4 A / dm ² , the production efficiency of indium hydroxide powder or tin hydroxide powder is lowered. On the other hand, when the current density during electrolysis exceeds 20 A / dm ² , problems such as rise of the electrolyte solution 11 and passivation on the surface of the anode 12 (for example, metal indium) make it difficult to perform electrolysis. It is not preferable.

(Electrolysis)
In the electrolysis process, the electrolysis apparatus 1 is prepared as shown in FIG. 1, and the electrolytic solution 11 is introduced into the electrolytic cell 10 and the adjustment tank 20 to start electrolysis.

  In the electrolysis step, the electrolytic solution 11 in the electrolytic cell 10 is adjusted in the adjustment tank 20 during electrolysis, and the circulation means 30 passes the supply channel 33 from the supply channel 33 through the supply pipe 37 to the inside of the electrolytic cell 10. To supply. In the electrolysis process, when supplying the electrolytic solution 11 into the electrolytic cell 10 by the circulation means 30, a plurality of supply nozzles 32, a suction nozzle 34 near the tank wall 17 b of the electrolytic cell 10, and a suction pump 35 are used. Then, the electrolytic solution 11 is transferred toward the adjusting tank 20, and a plurality of jets of the electrolytic solution 11 (laminar flow) are formed between the electrodes A and the gaps B and C between the electrodes and the tank walls 17 c and 17 d of the electrolytic tank 10. Form.

  In the electrolysis step, the electrolytic solution 11 is supplied from the adjustment tank 20 into the electrolytic tank 10, whereby the electrolytic solution 11 is sucked from the electrolytic tank 10 and provided at the upper edge of the tank wall 17 b of the electrolytic tank 10. The electrolytic solution 11 is returned to the adjusting tank 20 by overflowing from the drainage outlet 18.

  In the electrolysis process, the electrolytic solution 11 in the electrolytic cell 10 is transferred to the adjustment tank 20 through the suction channel 36 from the suction nozzle 34 provided near the tank wall 17b on the adjustment tank 20 side of the electrolytic cell 10. And the electrolytic solution 11 in the electrolytic cell 10 is overflowed and transferred through a drain port 18 provided at the upper edge of the tank wall 17b of the electrolytic cell 10, and the pH, liquid temperature, etc. are adjusted in the adjustment tank 20, The adjusted electrolytic solution 11 is again supplied from the supply nozzle 32 into the electrolytic cell 10 through the supply flow path 33 by the supply pump 31, and this is continuously performed, whereby the electrolytic solution 11 is electrolyzed by the circulation means 30. Circulate in 1.

  In the electrolysis step, after the electrolysis is completed, an electrolytic slurry containing indium hydroxide powder or tin hydroxide powder is obtained.

  In the electrolysis process, the composition, concentration, pH, liquid temperature, and the like of the electrolytic solution 11 in the electrolytic cell 10 change with the passage of energization time by electrolysis. More specifically, the composition, concentration, pH, liquid temperature, and the like of the electrolytic solution 11 in the vicinity of the liquid surface of the electrolytic cell 10 and in the vicinity of the cell bottom 14 become non-uniform with time, resulting in indium hydroxide powder or tin hydroxide being generated. Differences occur in the particle size of the powder.

  That is, in the adjustment tank 20, when the control and maintenance regarding the pH and the liquid temperature of the electrolytic solution 11 are not appropriately performed, the range of the particle size distribution of the generated indium hydroxide powder or tin hydroxide powder becomes wide. End up.

  Therefore, in the electrolysis process, in order to suppress the spread of the particle size distribution of the indium hydroxide powder or the tin hydroxide powder, the circulation means 30 allows the interelectrode A and the electrodes and the tank walls 17c and 17d of the electrolytic cell 10 to A laminar flow of the electrolytic solution is formed in the gaps B and C, and the electrolytic solution is circulated.

  As a result, in the electrolysis process, the laminar flow of the formed electrolytic solution 11 eliminates the stagnation of the electrolytic solution 11 between the electrodes A and the gaps B and C, and makes the composition, concentration, pH, liquid temperature, etc. uniform. be able to. Furthermore, in the electrolysis process, the circulation means 30 forms the laminar flow of the electrolyte solution 11 and circulates the electrolyte solution 11 into the electrolysis device 1, so that the composition, concentration, Uniformity of pH, liquid temperature, etc. can be achieved, and an electrolytic slurry containing indium hydroxide powder or tin hydroxide powder having a narrow particle size distribution can be generated.

<2-2. Electrolyte separation process>
Next, in the electrolytic solution separation step, the electrolytic solution 11 and the cake containing indium hydroxide powder or tin hydroxide powder are solid-liquid separated from the electrolytic slurry obtained by the above-described electrolysis step.

In the electrolytic solution separation step, since the electrolytic solution 11 is separated from the electrolytic slurry, it is difficult to cause clogging even if it is a fine powder, and a cross-flow rotary with high recovery efficiency of indium hydroxide powder or tin hydroxide powder. Use filters. The filter cloth used in the rotary filter is preferably as low in air permeability as possible in order to increase the recovery rate of indium hydroxide powder or tin hydroxide powder. In particular, in the electrolytic solution separation step, an air permeability of 0.3 cm ³ / sec / cm ² or less is preferable.

<2-3. Repulp washing process>
Next, in the repulp washing process, since the electrolyte solution 11 is contained in the cake containing indium hydroxide powder or tin hydroxide powder obtained in the electrolyte solution separation process, the washing solution is applied to the indium hydroxide powder or tin hydroxide powder. In addition, the indium hydroxide powder or the tin hydroxide powder is repulp washed to obtain a washing slurry.

  Since it is desirable that the cleaning liquid used for the repulp cleaning has less impurities, pure water is used. In the repulp washing process, it is particularly desirable that the washing liquid is A2 grade or higher as defined in “JIS K0557”. When using a cleaning liquid of A2 grade or lower, impurities such as silica are mixed, which causes a problem when producing a sputtering target using the generated indium hydroxide powder or tin hydroxide powder.

  In the repulp washing step, it is desirable to wash using 5 L to 20 L of pure water with respect to 1 kg of indium hydroxide powder or tin hydroxide powder contained in the cake. When the amount of pure water to be used is less than 5 L, a large amount of ammonium nitrate as an electrolyte component remains in the indium hydroxide powder or tin hydroxide powder, and the indium hydroxide powder or tin hydroxide powder When drying or calcining indium hydroxide powder or tin hydroxide powder to obtain indium oxide powder or tin oxide powder, the risk of fire is increased. On the other hand, in the repulp washing process, if 20 L of pure water can be used for washing, if more than 20 L of pure water is used, the amount of waste water treated after washing increases and the cost increases.

  In the repulp washing step, a washing solution is added to the cake containing indium hydroxide powder or tin hydroxide powder and stirred as necessary. In the repulp washing step, the electrolytic solution 11 in the cake containing indium hydroxide powder or tin hydroxide powder can be removed by performing repulp washing once or more, and the cake containing indium hydroxide powder or tin hydroxide powder is washed. Thus, a cleaning slurry can be obtained.

<2-4. Cleaning liquid dehydration process>
In the washing liquid dehydration step, the washing liquid is dehydrated from the washing slurry obtained in the repulp washing step to obtain indium hydroxide powder or tin hydroxide powder.

  For the dehydration, a cross-flow type rotary filter is used that is highly resistant to clogging even if it is a fine powder.

  When the electrolytic solution 11 or the cleaning solution is reused, in the cleaning solution dehydration step, the cleaning solution obtained by dehydrating the cleaning slurry is heated and distilled under reduced pressure for a predetermined time to obtain a concentrated solution. Next, in the washing liquid dehydration process, the obtained concentrated liquid is mixed with the electrolytic solution 11 separated in the electrolytic solution separation process, so that the concentration and pH are the same as the electrolytic solution 11 used in the electrolysis process. Adjust by adding water. Thereafter, in the washing liquid dehydration step, the electrolytic solution 11 adjusted by adding pure water is charged again into the adjustment tank 20 and supplied to the electrolytic tank through the supply flow path 33 by the supply pump 31.

  As a result, in the electrolysis process, new electrolysis can be performed using the electrolytic solution 11 regenerated in the cleaning liquid dehydration process. In addition, by reusing the electrolytic solution 11 and the cleaning solution, the electrolytic solution is not discarded as a waste solution, the cost associated with the waste solution treatment can be reduced, the loss of the electrolyte solution 11 can be suppressed, and the environment can be reduced. The load on can be suppressed.

<2-5. Drying process>
In the drying step, the indium hydroxide powder or tin hydroxide powder obtained in the cleaning liquid dehydration step is dried.

  In the drying process, the method for drying the indium hydroxide powder or tin hydroxide powder is not particularly limited, and for example, drying may be performed using a dryer such as a spray dryer, an air convection drying furnace, an infrared drying furnace or the like. it can. Among these, spray drying with a spray dryer is particularly preferable from the viewpoint of obtaining indium hydroxide powder or tin hydroxide powder having excellent uniformity in particle size and a narrow particle size distribution.

  The drying conditions are not particularly limited as long as moisture contained in the indium hydroxide powder or the tin hydroxide powder can be removed. For example, the drying temperature is preferably in the range of 80 ° C to 150 ° C. When the drying temperature is lower than 80 ° C., the drying is insufficient. When the drying temperature is higher than 150 ° C., the indium hydroxide or tin hydroxide is changed to indium oxide or tin oxide. Moreover, although drying time changes with temperature, it is about 10 hours-about 24 hours.

  As described above, in the method for producing indium hydroxide powder or tin hydroxide powder, by using the electrolytic apparatus according to the present embodiment as described above, the particle size is uniform and the particle size distribution is narrow. Indium powder or tin hydroxide powder can be obtained.

[3. Method for producing indium oxide powder or tin oxide powder]
In the method for producing indium oxide powder or tin oxide powder, the indium hydroxide powder or tin hydroxide powder after drying obtained by the drying process as described above is calcined to produce indium oxide powder or tin oxide powder. .

  In the method for producing indium oxide powder or tin oxide powder, these calcining conditions are appropriately determined according to the obtained indium hydroxide powder or tin hydroxide powder. For example, the calcining temperature is 600C to 800C. The calcining time is preferably 1 hour to 10 hours.

In the method for producing indium oxide powder or tin oxide powder, when the calcining temperature of indium hydroxide powder or tin hydroxide powder is lower than 600 ° C., the BET value of indium oxide powder or tin oxide powder exceeds 15 m ² / g. Therefore, since the primary particles are too small, the powder has cohesiveness. Thereby, with the obtained indium oxide powder or tin oxide powder, a high-density sintered material, for example, an indium tin oxide (ITO) sintered material cannot be obtained.

On the other hand, in the method for producing indium oxide powder or tin oxide powder, when the calcining temperature of indium hydroxide powder or tin hydroxide powder is higher than 800 ° C., the BET value of indium oxide powder or tin oxide powder is less than 10 m ² / g. Thus, the primary particle size is increased and the pores generated between the particles are also increased, so that the sinterability is lowered. Thereby, a high-density sintered material cannot be obtained with the obtained indium oxide powder or tin oxide powder.

  Therefore, in the method for producing indium oxide powder or tin oxide powder, the calcining temperature is preferably in the range of 600 ° C to 800 ° C in order to obtain a high-density sintered material.

In the method of manufacturing an indium oxide powder or tin oxide powder, in the obtained indium oxide powder or tin oxide powder, BET value of specific surface area are controlled in the range of 10m 2 ^/ g~15m 2 ^{/ g,} particle size The cumulative particle size 10% diameter (D10) of the distribution is 0.2 μm or more, and the cumulative particle size 90% diameter (D90) is 2.7 μm or less. Since such an indium oxide powder or tin oxide powder has a controlled specific surface area, it has good dispersibility and little aggregation, so that a high-density sintered material can be produced.

  In the method for producing indium oxide powder or tin oxide powder, the indium oxide powder or tin oxide powder may be crushed or pulverized as necessary in order to obtain a more desired particle size. In addition, in the method for producing indium oxide powder or tin oxide powder, when ammonium nitrate is used as an electrolytic solution during electrolysis of indium hydroxide powder or tin hydroxide powder, decomposition of ammonium nitrate occurs, and indium oxide powder or Mixing into the tin oxide powder can be prevented.

[4. Manufacturing method of sputtering target]
In the method for manufacturing a sputtering target according to the present embodiment, a sputtering target is manufactured using indium oxide powder and / or tin oxide powder obtained by the method for manufacturing indium oxide powder or tin oxide powder as described above.

  First, in the sputtering target manufacturing method, indium oxide powder and tin oxide powder obtained by the manufacturing method of indium oxide powder or tin oxide powder are mixed with other raw materials of the sputtering target at a predetermined ratio, and the granulated powder is mixed. Make it. Next, in the manufacturing method of a sputtering target, a molded object is produced by the code press method using the obtained granulated powder. Next, in the manufacturing method of a sputtering target, the obtained molded object is sintered in the temperature range of 1300 degreeC-1600 degreeC under atmospheric pressure, for example. Next, in the manufacturing method of a sputtering target, the process of grind | polishing the plane and side surface of the obtained sintered compact is performed as needed. And in the manufacturing method of a sputtering target, an indium tin oxide sputtering target (ITO sputtering target) can be obtained by bonding the sintered body after processing to a Cu backing plate.

  In the manufacturing method of the sputtering target, the specific surface area of the indium oxide powder and tin oxide powder as raw materials is controlled and the dispersibility is good, so that a high-density sintered body can be obtained. The density can be increased. As a result, the obtained sputtering target is free from cracks during processing, and it is possible to suppress the occurrence of abnormal discharge during sputtering.

  In the method for producing a sputtering target, the indium oxide powder or the tin oxide powder obtained by the method for producing indium oxide powder or tin oxide powder can be used alone to produce an indium oxide sputtering target or a tin oxide sputtering target. Good.

  Moreover, in the manufacturing method of a sputtering target, when producing an ITO sputtering target, what was obtained by the other manufacturing method may be applied about either indium oxide powder or tin oxide powder, but it was mentioned above. It is preferable to use what was produced using the indium hydroxide powder or the tin hydroxide powder manufactured with the usual electrolytic device.

  As described above, in the method for manufacturing a sputtering target, the particle diameter is uniform and the particle size distribution width obtained by the method for manufacturing indium hydroxide powder or tin hydroxide powder according to the present embodiment as described above. Indium oxide powder and / or tin oxide powder prepared using narrow indium hydroxide powder or tin hydroxide powder is used as a raw material for the sputtering target. As a result, in the sputtering target manufacturing method, a sintered body having a high relative density can be obtained, and finally, a high-density sputtering target can be produced using the sintered body.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example and a comparative example, this invention is not limited to these Examples and a comparative example.

[Example 1]
(1) Electrolysis process In the electrolysis process in Example 1, indium hydroxide powder was produced | generated using the electrolyzer 1 shown in FIG. The electrolysis apparatus 1 includes a 200 L electrolytic tank 10 having a length of 100 cm, a width of 40 cm, and a depth of 50 cm, and a 40 L adjustment tank 20 having a length of 20 cm, a width of 40 cm, and a depth of 50 cm. Are provided adjacent to each other. As shown in FIGS. 1 and 2, in the electrolysis apparatus 1, the electrolytic tank 10 and the adjustment tank 20 are connected by a supply flow path 33 and a suction flow path 36, and the supply flow path 33 includes a supply pump 31 and a supply nozzle 32. And a liquid supply pipe 37 provided with.

  As shown in FIG. 2, a plurality of anodes (anodes) 12 and cathodes (cathodes) 13 are arranged in the electrolytic cell 10 in the electrolytic cell 10. In Example 1, four sheets of indium metal having a purity of 99.9999% molded into a plate shape having a width of 26 cm, a height of 40 cm, and a thickness of 8 mm were prepared for the anode 12, and the cathode 13 had a width of 26 cm and a height of Five titanium metal plates having a thickness of 40 cm and a thickness of 4 mm were prepared.

As shown in FIG. 2, in the electrolytic cell 10, five cathodes 13 and four anodes 12 are vertically arranged so that the electrolytic area of one side of the anode 12 is 10.4 dm ² , and both electrodes are parallel to each other. The distance between the cathode 13 and the anode 12 was adjusted to 2.0 cm. In Example 1, the five cathodes 13 and the four anodes 12 were electrically connected by the conducting wire 15a.

  Further, as shown in FIG. 2, the electrolytic cell 10 is provided with a supply nozzle 32 for dispersing the liquid flow of the electrolytic solution 11 at a height of 2 cm from the cell bottom 14 in parallel with the width direction of the electrode. . That is, in the supply nozzle 32, five cathodes 13 are alternately arranged in parallel to the four anodes 12, and the supply nozzle 32 is located in the middle between the electrodes. Five supply nozzles 32 are arranged at equal intervals from the upper point where the electrode is immersed to the lower point of the electrode. As for the supply nozzle 32, ten supply nozzles 32 are arranged for a total of nine rows of four anodes and five cathodes. Therefore, the electrolyte solution 11 is supplied in a uniform and constant amount by a total of 50 supply nozzles 32 and flows between the electrodes as a laminar flow. Further, a suction nozzle 34 is provided in the vicinity of the tank wall 17b opposite to the tank wall 17a where the supply nozzle 32 is provided, and the electrolyte 11 supplied from the supply nozzle 32 by the suction pump 35 is sucked from the suction nozzle 34 to be adjusted tank. The linear flow and the laminar flow are maintained substantially constant by transferring the electrolytic solution 11 that has been transferred to 20 and overflowed from the electrolytic bath 10 to the adjustment bath 20.

  As shown in FIG. 3, the supply nozzle 32 has a projecting pipe having a supply nozzle inner diameter D of 5 mm and a supply nozzle length L of 10 mm. Further, as shown in FIG. 1, a suction flow path 36 for sucking the electrolyte solution 11 from the suction nozzle 34 is disposed between the adjustment tank 20 and the electrolytic tank 10.

  Further, as shown in FIG. 1, the inside of the adjustment tank 20 is a stirring rod 21 for stirring the electrolytic solution 11, a pH electrode 22 for measuring pH, a heater 23 and a cooler 24 for controlling and maintaining the liquid temperature of the electrolytic solution 11. Is provided. In the first embodiment, a chemical tank 25 for controlling and maintaining the pH of the electrolyte solution 11 and a metering pump 26 for adding chemical solution are provided in the vicinity of the adjustment tank 20.

  The adjustment tank 20 of the electrolysis apparatus 1 is charged with 180 L of 1.0 mol / L ammonium nitrate aqueous solution as the electrolyte 11. In Example 1, 1N nitric acid was added to the ammonium nitrate aqueous solution in the adjustment tank 20, and the hydrogen ion concentration index pH was adjusted to 4.0. The pH of the electrolytic solution 11 was measured using a pH electrode 22 attached to the adjustment tank 20. Moreover, in the electrolyte solution 11, the temperature of the electrolyte solution 11 was maintained at 25 degreeC using the heater 23 and the cooler 24 further, maintaining this pH. In the adjustment tank 20, the electrolyte solution 11 was adjusted by stirring the electrolyte solution 11 in the tank with the stirring rod 21.

  In the first embodiment, during electrolysis, the supply pump 31 supplies the electrolyte 11 in the adjustment tank 20 to the supply pipe 37 through the supply flow path 33, and further supplies the supply pipe 37. It sprayed from the nozzle 32 and supplied to the electrolytic cell 10. Then, the electrolyte solution 11 in the electrolytic cell 10 is caused to flow through the suction flow path 36 by the suction pump 35 at a circulation amount of 0.06 L / min / A (circulation amount 74.9 L / min) per 1 A of the electrolytic current. The electrolytic solution 11 that was transferred to the adjustment tank 20 and overflowed from the electrolytic tank 10 was sent to the adjustment tank 20. Here, the total supply amount of the electrolytic solution was 125% with respect to the circulating amount of the electrolytic solution. The electrolytic solution 11 in the electrolytic cell 10 is transferred from the suction nozzle 34 provided in the vicinity of the tank wall 17 b of the electrolytic cell 10 to the adjustment tank 20 through the suction channel 36 by the suction pump 35. And it circulates between the adjustment tanks 20.

In the electrolysis apparatus 1, the electrode current density was adjusted to 15 A / dm ² and electrolysis was continued for 6 hours. By this electrolysis, an electrolytic slurry containing indium hydroxide powder was obtained in the electrolysis process.

(2) Electrolytic Solution Separation Step Next, in the electrolytic solution separation step in Example 1, solid-liquid separation of the electrolytic slurry containing indium hydroxide powder obtained in the electrolysis step was performed. In the electrolytic solution separation step, when performing solid-liquid separation of the electrolytic slurry containing indium hydroxide powder, a rotary filter (manufactured by Kotobuki Industries Co., Ltd., RFU-02B) and a filter cloth (KE-022, air permeability 0.1 cm) ³ / sec / cm ² ) was used. As a result, in the electrolytic solution separation step, a cake containing indium hydroxide and the separated electrolytic solution 11 were obtained by solid-liquid separation.

(3) Repulp washing process Next, in the repulp washing process in Example 1, the cake containing indium hydroxide obtained in the electrolytic solution separation process was washed. In the repulp washing step, pure water was added to the cake containing indium hydroxide and stirred in a stainless bucket container to redisperse. Next, in the repulp washing step, a solid-liquid separation operation was performed in the same manner as in the electrolytic solution separation step, and a cake containing indium hydroxide and a separated washing solution were obtained again.

(4) Cleaning liquid dehydration process Next, in the cleaning liquid dehydration process in Example 1, repulping was performed on a heater / heater for concentration heating (capacity 1 m ³ ) using a vacuum distillation apparatus (manufactured by Nippon Steel & Sumitomo Environment Co., Ltd., Eco Prima). 100 L of the cleaning liquid obtained in the cleaning process was charged and distilled under reduced pressure for 4 hours with an electric heater 100 kW / hr to obtain a concentrated liquid.

  Next, in the washing liquid dehydration process, the obtained concentrated liquid is mixed with the electrolytic solution 11 obtained in the electrolytic solution separation process, so that the concentration, pH, etc. of the electrolytic solution 11 used in the electrolysis process are the same. After adjusting by adding water, it was again put into the adjustment tank 20 and supplied to the electrolytic cell 10 by the supply pump 31 via the supply flow path 33 to perform new electrolysis. In the process up to the cleaning liquid dehydrating process, the electrolytic solution 11 was not discarded as a waste liquid.

  In Example 1, the operation in the washing liquid dehydration step was repeated three times, the obtained electrolytic slurry containing indium hydroxide powder was sampled, and the particle size distribution was measured by a laser diffraction / scattering method (SALD-2200, manufactured by Shimadzu Corporation). It was measured by.

(5) Drying step In Example 1, the electrolytic slurry containing the indium hydroxide powder obtained by the cleaning liquid dehydration step was spray-dried with a spray dryer. In Example 1, the particle size distribution was measured for the dried indium hydroxide powder, and the results are shown in Table 1.

(6) Manufacturing process of indium oxide powder In Example 1, the indium hydroxide powder dried at the drying process was baked at 700 degreeC in air | atmosphere, and the indium oxide powder was obtained. In Example 1, the manufacturing conditions of the obtained indium oxide powder were summarized and shown in Table 1.

[Example 2]
In Example 2, an indium hydroxide powder was produced in the same manner as in Example 1 except that the amount of liquid in the adjustment tank 20 was changed to 200 L, and indium oxide powder was produced from the indium hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 2, the particle size distribution of the produced indium hydroxide powder and the production conditions of the indium oxide powder are summarized in Table 1.

[Example 3]
In Example 3, an indium hydroxide powder was produced in the same manner as in Example 1 except that the circulating amount of the electrolytic solution per electrolytic current 1 A was 0.035 L / min / A (circulating amount 43.8 L / min). And indium oxide powder was produced from the indium hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 3, the particle size distribution of the produced indium hydroxide powder and the production conditions of the indium oxide powder are summarized in Table 1.

[Example 4]
In Example 4, an indium hydroxide powder was produced in the same manner as in Example 1 except that the circulating amount of the electrolytic solution per electrolytic current 1 A was 0.095 L / min / A (circulating amount 118.6 L / min). And indium oxide powder was produced from the indium hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 4, the particle size distribution of the produced indium hydroxide powder and the production conditions of the indium oxide powder are summarized in Table 1.

[Example 5]
In Example 5, tin hydroxide powder was prepared in the same manner as in Example 1 except that metal tin having a purity of 99.99% was used for the anode 12 and the pH of the electrolyte solution 11 was adjusted to 7.0. Tin oxide powder was produced from the tin hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 5, the particle size distribution of the produced tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Example 6]
In Example 6, a tin hydroxide powder was produced in the same manner as in Example 5 except that the amount of liquid in the adjustment tank 20 was 200 L, and a tin oxide powder was produced from the tin hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 6, the particle size distribution of the produced tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Example 7]
In Example 7, tin hydroxide powder was prepared in the same manner as in Example 5 except that the circulating amount of the electrolytic solution per electrolytic current 1 A was 0.035 L / min / A (circulating amount 43.8 L / min). And the tin oxide powder was produced from the tin hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 7, the particle size distribution of the produced tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Example 8]
In Example 8, tin hydroxide powder was produced in the same manner as in Example 5 except that the circulating amount of the electrolytic solution per electrolytic current 1 A was 0.095 L / min / A (circulating amount 118.6 L / min). And the tin oxide powder was produced from the tin hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Example 8, the particle size distribution of the prepared tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Example 9]
In Example 9, using 990 g of the indium oxide powder obtained in Example 1 and 10 g of the tin oxide powder obtained in Example 5, a compact was formed by a mixed cold press method. Next, in Example 9, the obtained molded body was sintered at 1400 ° C. for 30 hours in an atmospheric pressure to obtain an indium oxide-tin oxide based sintered body. In Example 9, the relative density of the obtained sintered body was measured by Archimedes method, and the result is shown in Table 3.

[Example 10]
In Example 10, using 990 g of the indium oxide powder obtained in Example 2 and 10 g of the tin oxide powder obtained in Example 6, a compact was formed by a mixed cold press method. Next, in Example 10, the obtained molded body was sintered at 1400 ° C. for 30 hours in an atmospheric pressure to obtain an indium oxide-tin oxide based sintered body. In Example 10, the relative density of the obtained sintered body was measured by the Archimedes method, and the results are shown in Table 3.

[Comparative Example 1]
In Comparative Example 1, electrolysis was performed only in the electrolytic cell 10 without using the adjustment tank 20, and the stirring rod 21, pH electrode 22, heater 23, and cooler 24 were installed in the electrolytic cell 10. In Comparative Example 1, indium hydroxide powder was produced in the same manner as in Example 1 except that the rotation speed of the stirring rod 21 in the electrolytic cell 10 was set to 60 rpm, and indium oxide powder was produced from the indium hydroxide powder. did. In Comparative Example 1, the particle size distribution of the produced indium hydroxide powder and the production conditions of the indium oxide powder are summarized in Table 1.

[Comparative Example 2]
In Comparative Example 2, electrolysis was performed only in the electrolytic cell 10 without using the adjustment tank 20, and the stirring rod 21, pH electrode 22, heater 23, and cooler 24 were installed in the electrolytic cell 10. In Comparative Example 2, indium hydroxide powder was produced in the same manner as in Example 1 except that the rotation speed of the stirring rod 21 in the electrolytic cell 10 was set to 300 rpm, and indium oxide powder was produced from the indium hydroxide powder. did. In Comparative Example 2, the particle size distribution of the produced indium hydroxide powder and the production conditions of the indium oxide powder are summarized in Table 1.

[Comparative Example 3]
In Comparative Example 3, an indium hydroxide powder was produced in the same manner as in Example 1 except that the circulating amount of the electrolytic solution per electrolytic current 1A was 0.02 L / min / A (circulating amount 25.0 L / min). And indium oxide powder was produced from the indium hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Comparative Example 3, the particle size distribution of the produced indium hydroxide powder and the production conditions of the indium oxide powder are summarized in Table 1.

[Comparative Example 4]
In Comparative Example 4, an indium hydroxide powder was produced in the same manner as in Example 1 except that the circulating amount of the electrolytic solution per electrolytic current 1A was 0.15 L / min / A (circulating amount 187.2 L / min). And indium oxide powder was produced from the indium hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Comparative Example 4, the particle size distribution of the produced indium hydroxide powder and the production conditions for the indium oxide powder are summarized in Table 1.

[Comparative Example 5]
In Comparative Example 5, electrolysis was performed only in the electrolytic cell 10 without using the adjustment tank 20, and the stirring rod 21, pH electrode 22, heater 23, and cooler 24 were installed in the electrolytic cell 10. In Comparative Example 5, a tin hydroxide powder was produced in the same manner as in Example 5 except that the rotation speed of the stirring rod 21 in the electrolytic cell 10 was set to 60 rpm, and a tin oxide powder was produced from the tin hydroxide powder. did. In Comparative Example 5, the particle size distribution of the produced tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Comparative Example 6]
In Comparative Example 6, electrolysis was performed only in the electrolytic cell 10 without using the adjustment tank 20, and the stirring rod 21, pH electrode 22, heater 23, and cooler 24 were installed in the electrolytic cell 10. In Comparative Example 6, a tin hydroxide powder was produced in the same manner as in Example 5 except that the rotation speed of the stirring rod 21 in the electrolytic cell 10 was set to 300 rpm, and a tin oxide powder was produced from the tin hydroxide powder. did. In Comparative Example 6, the particle size distribution of the produced tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Comparative Example 7]
In Comparative Example 7, tin hydroxide powder was prepared in the same manner as in Example 5 except that the circulating amount of the electrolytic solution per electrolytic current 1 A was 0.02 L / min / A (circulating amount 25.0 L / min). And the tin oxide powder was produced from the tin hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Comparative Example 7, the particle size distribution of the produced tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Comparative Example 8]
In Comparative Example 8, tin hydroxide powder was produced in the same manner as in Example 5 except that the circulating amount of the electrolytic solution per electrolytic current 1A was 0.15 L / min / A (circulating amount 187.2 L / min). And the tin oxide powder was produced from the tin hydroxide powder. The total amount of electrolyte supplied was 125% with respect to the amount of electrolyte circulated. In Comparative Example 8, the particle size distribution of the prepared tin hydroxide powder and the production conditions of the tin oxide powder are summarized in Table 2.

[Comparative Example 9]
In Comparative Example 9, a molded body was formed by a mixed cold press method using 990 g of indium oxide powder obtained in Comparative Example 1 and 10 g of tin oxide powder obtained in Comparative Example 5. Next, in Comparative Example 9, the obtained molded body was sintered at 1400 ° C. for 30 hours in an atmospheric pressure to obtain an indium oxide-tin oxide based sintered body. In Comparative Example 9, the relative density of the obtained sintered body was measured by the Archimedes method, and the results are shown in Table 3.

[Comparative Example 10]
In Comparative Example 10, a molded body was formed by a mixed cold press method using 990 g of the indium oxide powder obtained in Comparative Example 3 and 10 g of the tin oxide powder obtained in Comparative Example 7. Next, in Comparative Example 10, the obtained molded body was sintered at 1400 ° C. for 30 hours in an atmospheric pressure to obtain an indium oxide-tin oxide based sintered body. In Comparative Example 10, the relative density of the obtained sintered body was measured by Archimedes method, and the result is shown in Table 3.

  From the results shown in Table 1, in Examples 1 to 4, it was found that indium hydroxide powder having a minimum diameter of 0.3 μm and a maximum diameter of 1.1 μm and having a very narrow particle size distribution can be obtained. .

  On the other hand, in Comparative Example 1 and Comparative Example 2, electrolysis is performed only in the electrolytic cell 10 without using the adjustment tank 20, and in Comparative Example 3, 0.02 L / min / A (per electrolytic current of 1 A of the circulating amount of the electrolytic solution ( The circulation rate was 25.0 L / min). As a result, as shown in Table 1, it was found that in Comparative Examples 1 to 3, indium hydroxide powder having a wider particle size distribution than in Examples 1 to 4 was obtained.

  Further, in Comparative Example 4, electrolysis was performed at 0.15 L / min / A (circulation amount 187.2 L / min) per electrolytic current 1 A of the circulation amount of the electrolytic solution. As a result, as shown in Table 1, in Comparative Example 4, the volatilization of the electrolytic solution and the scattering of mist were intense and the electrolysis was stopped, so that indium hydroxide powder could not be obtained. Furthermore, in Comparative Example 4, it was found that there was a problem in terms of environmental deterioration and safety in the vicinity of the electrolytic device 1 due to volatilization of the electrolytic solution, scattering of mist, and the like.

  From the results shown in Table 2, it was found that in Examples 5 to 8, tin hydroxide powder having a minimum diameter of 0.3 μm and a maximum diameter of 3.3 μm and having a very narrow particle size distribution was obtained. .

  On the other hand, in Comparative Example 5 and Comparative Example 6, electrolysis is performed only in the electrolytic cell 10 without using the adjustment tank 20, and in Comparative Example 7, 0.02 L / min / A ( The circulation rate was 25.0 L / min). As a result, as shown in Table 2, it was found that in Comparative Examples 5 to 7, tin hydroxide powder having a wider particle size distribution than in Examples 5 to 8 was obtained.

  Further, in Comparative Example 8, electrolysis was performed at 0.15 L / min / A (circulation amount 187.2 L / min) per electrolytic current 1 A of the circulation amount of the electrolytic solution. As a result, as shown in Table 2, in Comparative Example 8, the volatilization of the electrolytic solution and the scattering of mist were intense, and the electrolysis was stopped, so that tin hydroxide powder could not be obtained. Furthermore, in Comparative Example 8, it was found that there was a problem in environmental deterioration and safety in the vicinity of the electrolytic device 1 due to volatilization of the electrolytic solution, scattering of mist, and the like.

  From the results shown in Table 3, it was found that in Example 9 and Example 10, a very high density sintered body having a relative density of 90% or more was obtained.

  On the other hand, in Comparative Example 9 and Comparative Example 10, the particle size distribution of the indium oxide powder and the tin oxide powder was widened by using the indium hydroxide powder and the tin hydroxide powder having a wide particle size distribution. As a result, as shown in Table 3, in Comparative Example 9 and Comparative Example 10, it was found that a sintered body having a relative density lower than that of Example 9 and Example 10 was obtained.

  From the results of Examples 1 to 10 and Comparative Examples 1 to 10, by using the electrolysis apparatus 1 having the circulation means 30, a laminar flow of the electrolyte solution 11 is formed between the electrodes, and the laminar flow Since the electrolytic solution 11 is circulated in a constant flow, the composition, concentration, pH, liquid temperature, etc. of the electrolytic solution 11 can be made uniform. Therefore, it is possible to obtain indium hydroxide powder or tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution. Further, by using such indium hydroxide powder and / or tin hydroxide powder, an indium oxide-tin oxide based sintered body having a high relative density can be obtained. A high-density sputtering target can be produced.

  DESCRIPTION OF SYMBOLS 1 Electrolyzer, 10 Electrolyzer, 11 Electrolyte, 12 Anode (anode), 13 Cathode (cathode), 14 Tank bottom, 15a, 15b Conductor, 16 Insertion port, 17a, 17b Tank wall, 18 Drainage port, 20 Adjustment tank , 21 Stirring rod, 22 pH electrode, 23 Heater, 24 Cooler, 25 Chemical liquid tank, 26 Metering pump, 27 Tank bottom, 28 Liquid feeding port, 30 Circulating means, 31 Supply pump, 32 Supply nozzle, 33 Supply flow path, 34 Suction nozzle, 35 Suction pump, 36 Suction flow path, 37 Liquid supply pipe, 38 Transfer port, A Between electrodes, B, C gap, D Supply nozzle inner diameter, L Supply nozzle length

Claims (8)

An electrolysis device for producing indium hydroxide powder or tin hydroxide powder by electrolyzing indium or tin,
An electrolytic cell for storing an electrolytic solution, and a plurality of electrodes provided in parallel at a predetermined interval;
An adjustment tank for adjusting the electrolytic solution;
A supply nozzle that is provided in the vicinity of one tank wall of the electrolytic cell in multiple stages in the vertical direction of the electrode, and jets an electrolytic solution between at least the electrodes in parallel with the width direction of the electrode;
A suction nozzle provided in the vicinity of the tank wall of the electrolytic cell in multiple stages in the vertical direction of the electrode at a position facing the supply nozzle;
The electrolyte is supplied from the adjustment tank via the supply nozzle, and the electrolyte is jetted in parallel with the width direction of the electrode toward the adjustment tank, and the electrolyte is sucked through the suction nozzle. By forming a laminar flow of the electrolyte solution in a straight line and transferring the electrolyte solution to the adjustment tank, the electrolyte solution is circulated between the electrolyte tank and the adjustment tank. Electrolytic device for indium oxide powder or tin hydroxide powder. The circulating amount of the electrolytic solution for transferring the electrolytic solution from the suction nozzle provided in the electrolytic bath to the adjusting tank is 0.03 L / min / A per electrolytic current 1A to 0.10 L / min / A per electrolytic current 1A. The indium hydroxide powder or tin hydroxide powder electrolyzer according to claim 1 , wherein In order to overflow the electrolytic solution from the electrolytic tank to the adjustment tank, a drain port is provided at the upper edge of the tank wall on the adjustment tank side of the electrolytic tank,
The total supply amount of the electrolyte solution, which is the sum of the amount of the electrolyte solution overflowing from the drain port and transferring the electrolyte solution to the adjustment tank and the circulation amount of the electrolyte solution, is based on the circulation amount of the electrolyte solution. The electrolysis apparatus for indium hydroxide powder or tin hydroxide powder according to claim 1 or 2 , wherein the electrolysis apparatus is controlled to 110% to 160%. The indium hydroxide powder or tin hydroxide powder electrolysis apparatus according to any one of claims 1 to 3 , wherein a volume ratio of the adjusting tank to the electrolytic tank is 0.1 or more. . Indium or tin as an anode, indium hydroxide powder or tin hydroxide powder is produced by electrolysis to produce indium hydroxide powder or tin hydroxide powder,
A method for producing indium hydroxide powder or tin hydroxide powder, wherein the electrolytic apparatus according to any one of claims 1 to 4 is used. When the anode is indium, a 0.1 mol / L to 2.0 mol / L ammonium nitrate aqueous solution is used as the electrolytic solution, the pH of the electrolytic solution is 2.5 to 4.0, and the liquid temperature is 20 ° C. to 60 ° C., and method of manufacturing the indium hydroxide powder according to claim 5, characterized in that controlling the electrodes current density in the range of ^{4A / dm 2 ~20A / dm 2} . When the anode is tin, a 0.1 mol / L to 2.0 mol / L ammonium nitrate aqueous solution is used as the electrolytic solution, the pH of the electrolytic solution is 2.5 to 8.0, and the liquid temperature is 20 ° C. to 60 ° C., and method for producing a tin hydroxide powder according to claim 5, characterized in that controlling the electrodes current density in the range of ^{4A / dm 2 ~20A / dm 2} . A sputtering target is produced using the indium hydroxide powder and / or tin hydroxide powder obtained by the method for producing indium hydroxide powder or tin hydroxide powder according to any one of claims 5 to 7. A method for producing a sputtering target, comprising:

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