JP6201195B2 - 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 electrolyzer capable of producing indium hydroxide powder or tin hydroxide powder having a narrow particle size distribution, and indium hydroxide or tin hydroxide using the electrolyzer 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 size, 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, since Patent Document 5 requires a high electrolyte supply speed in order to circulate the electrolyte, the environment around the electrolytic device is deteriorated due to volatilization of the electrolyte, scattering of mist, and the like in terms of safety. There is a problem.

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

  However, in the electrolytic precipitation step of Patent Document 6, it is difficult to say that a technique for obtaining an electrolytic precipitation 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 provided with a plurality of electrodes, an adjustment tank for adjusting the electrolytic solution, and a plurality of nozzles connected to the electrolytic tank and the adjustment tank and supplying the electrolytic solution into the electrolytic tank are opposite to the adjustment tank of the electrolytic cell Circulating means for circulating the electrolytic solution provided near the tank wall on the side, and a drain outlet for overflowing the electrolytic solution from the electrolytic cell to the regulating tank at the upper end of the tank wall provided between the electrolytic cell and the regulating tank And the circulating means jets the electrolyte parallel to the electrode from the nozzle toward the adjustment tank.

  In the electrolysis apparatus of indium hydroxide powder or tin hydroxide powder, it is desirable that the nozzle is provided to face between the electrodes.

  In the indium hydroxide powder or tin hydroxide powder electrolyzer, the nozzles are preferably provided in multiple stages.

  In the electrolysis apparatus of indium hydroxide powder or tin hydroxide powder, the volume ratio of the adjusting tank to the electrolytic tank is preferably 0.1 or more.

  The method for producing indium hydroxide powder or tin hydroxide powder is a method for producing indium hydroxide powder or tin hydroxide powder by producing indium hydroxide powder or tin hydroxide powder by electrolysis using indium or tin as an anode. The electrolysis apparatus of indium hydroxide powder or tin hydroxide powder is used.

  In the method for producing indium hydroxide powder or tin hydroxide powder, the electrolyte flow rate per electrolytic cell is preferably 0.007 L / min / A to 0.03 L / min / A.

In the method for producing indium hydroxide powder, when the anode is indium, 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 4.0. the liquid temperature 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 the method for producing tin hydroxide powder, when the anode is tin, 0.1 mol / L to 2.0 mol / L of an aqueous ammonium nitrate solution is used as the electrolyte, and the pH of the electrolyte is 2.5 to 8.0. the liquid temperature 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} .

  A method for producing a sputtering target is characterized in that 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 the present invention, it is possible to obtain an indium hydroxide powder or a tin hydroxide powder having excellent particle size uniformity and a narrow particle size distribution. 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 top view 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 unit 30 that supplies the electrolytic solution 11 from the adjustment tank 20 to the electrolysis tank 10. The circulation means 30 includes a supply flow path 31 connected to the electrolytic bath 10 and the adjustment bath 20, a circulation pump 32, and a nozzle 33 that discharges the electrolytic solution 11.

  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 31 by the pressure of the circulation pump 32 and discharging it from the nozzle 33. Can do. When the electrolytic solution 11 is continuously supplied into the electrolytic bath 10, the electrolytic solution 11 in the electrolytic bath 10 overflows and is discharged to the adjustment bath 20. In the electrolytic device 1, the electrolytic solution 11 is discharged from the electrolytic bath 10. It becomes possible to make it circulate between the adjustment tanks 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 device. For example, the electrolytic cell and the adjustment vessel can be separated, and the electrolytic cell can be made to be adjacent to the adjustment vessel so that the electrolytic solution can overflow from the electrolytic cell to the adjustment vessel.

<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. The tank bottom 14 of the electrolytic cell 10 is provided with an insertion port 16 through which the supply flow path 31 is inserted, and is disposed between the electrolytic cell 10 and the adjustment tank 20 as shown in FIG. The tank wall 17a is provided with a drain port 18 serving as a flow path when the electrolyte solution 11 overflows.

  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.

  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 or platinum can be used, and titanium can be coated with platinum, and the same material as the anode 12 is used. May be. 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 17 b on the opposite side of 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. For example, the insertion port 16 is formed from the tank wall 17b to the electrolytic cell 10. 17d may be provided. The shape of the insertion port 16 can be appropriately changed according to the shape of the supply flow path 31 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 a disposed between the electrolytic cell 10 and the adjustment tank 20. That is, the upper end edge of the tank wall 17 a becomes the drain port 18, so that the electrolyte solution 11 can get over the upper end edge of the tank wall 17 a and overflow the electrolyte solution 11 from the electrolytic tank 10 to the adjustment tank 20.

  The drain port 18 may be provided by cutting out a part of the tank wall 17 a at the center of the upper edge of the tank wall 17 a disposed between the electrolytic cell 10 and the adjusting tank 20. 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 in the cutout can stabilize the amount of the electrolytic solution 11 to flow as compared with the case of overflowing from the entire upper end edge of the tank wall 17a. 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 31.

  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, for example, rounded corners so that the electrolyte solution 11 can flow and local liquid temperature and pH are not unevenly distributed.

  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 width of the particle size distribution of indium hydroxide powder or tin hydroxide powder Is not preferable because it becomes wide.

  In the adjustment tank 20, the charged electrolytic solution 11 is stirred by the stirring rod 21, and the pH and liquid temperature can be made uniform. At this time, the pH 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. . 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 liquid temperature 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 31 to be connected, and can be, for example, circular or elliptical.

<1-3. Circulation means>
As shown in FIG. 1 and FIG. 2, the circulation means 30 electrolyzes the supply channel 31 connected to the electrolytic cell 10 and the adjustment cell 20, the circulation pump 32 provided in the supply channel 31, and the electrolytic solution 11. A plurality of nozzles 33 for discharging into the tank 10 and a plurality of liquid supply pipes 34 connected to the supply flow path 31 and provided with the plurality of nozzles 33 are provided.

  The supply channel 31 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 channel 31 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 31 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 is not exposed from the liquid surface of the electrolytic solution 11. A plurality of liquid supply pipes 34 are connected to the supply flow path 31 in the electrolytic cell 10. Note that the installation position of the supply flow path 31 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 circulation pump 32 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 31 by adjusting the pressure of the circulation pump 32, and supplies the liquid. It is sent out from the nozzle 33 into the electrolytic cell 10 through the pipe 34.

  The plurality of nozzles 33 are respectively provided in the liquid supply pipe 34 so as to be positioned between the electrodes and the tank wall 17b of the electrolytic cell 10 and inserted between the electrodes A. Further, the plurality of nozzles 33 are located between the electrode and the tank wall 17b of the electrolytic cell 10 and are inserted into the gaps B and C between the electrode and the two tank walls 17c and 17d in the longitudinal direction of the electrolytic cell 10. Each of the liquid supply pipes 34 may be provided.

  With this configuration, the circulation means 30 can reliably supply the electrolytic solution 11 discharged from the nozzle 33 to the interelectrode A and the gaps B and C in the electrolytic cell 10. Furthermore, in the circulation means 30, by arranging the nozzle 33 as described above, it is unidirectional from the tank wall 17b side of the electrolytic cell 10 toward the adjusting tank 20 side, that is, linear (in the electrolytic cell 10 shown in FIG. 1). The electrolyte solution 11 can be fed in the direction of the arrow). That is, in the circulation means 30, the electrolytic solution 11 is jetted from the nozzle 33 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 b 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 nozzles 33 are provided in the liquid supply pipe 34, respectively, so that the jet of the electrolytic solution 11 can flow through all the electrodes A and the gaps B and C. . With this configuration, in the circulation means 30, compared with the case where the nozzle 33 is used alone, the electrolytic solution 11 in the entire electrolytic cell 10 is transferred to the tank wall 17 b side of the electrolytic cell 10 without applying a load to the circulation pump 32. Can be fed in one direction toward the adjustment tank 20 side.

  In the circulation means 30, the shape of the nozzle 33 is not particularly limited, but in order to ensure the straightness and speed of the jet of the electrolyte solution 11, the shape of the discharge port of the nozzle 33, the diameter dimension, etc. Is preferably controlled. 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 circulation pump 32 and appropriately changing the nozzle inner diameter D.

  For example, as shown in FIG. 3, the nozzle 33 preferably has a protruding tube constituted by a predetermined nozzle inner diameter D and a nozzle length L. In the protruding tube of the nozzle 33, the nozzle inner diameter D is preferably 3 mm or more, particularly preferably 5 mm to 10 mm, and the nozzle length L is preferably 3 mm to 20 mm.

  The nozzles 33 are preferably arranged in multiple stages at predetermined intervals with respect to the height direction of the electrodes. With this configuration, the jet of the electrolyte solution 11 formed as described above is discharged from the nozzles 33 arranged at predetermined intervals with respect to the height direction of the electrodes, and they are all aligned toward the adjustment tank 20. By flowing, a laminar flow of the electrolytic solution 11 is formed.

  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 substantially uniform, and the generated indium hydroxide powder or hydroxide Since the spread of the width of the particle size distribution of the tin powder can be suppressed, the liquid supply pipe is arranged so that the nozzle 33 is located between the electrode and the tank wall 17b of the electrolytic cell 10 and is inserted into the interelectrode A. 34 may be provided respectively.

  The number of nozzles 33 installed 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 34 is a pipe for supplying the electrolytic solution 11 fed from the adjustment tank 20 through the supply flow path 31 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 34 are arranged in multiple stages at predetermined intervals in the height direction of the electrodes, and one end of the liquid supply pipe 34 is connected to the supply flow path 31. Has been. With this configuration, in the electrolysis apparatus 1, the electrolytic solution 11 fed from the adjustment tank 20 through the supply flow path 31 can be supplied into the electrolytic tank 10 through the nozzle 33. The electrodes can be arranged in multiple stages at predetermined intervals with respect to the height direction of the electrodes.

  As described above, the electrolysis apparatus 1 of indium hydroxide powder or tin hydroxide powder is connected to the electrolytic bath 10 and the regulating bath 20, and a plurality of nozzles 33 for supplying the electrolytic solution 11 into the electrolytic bath 10 are arranged in the regulating bath. 20 is provided in the vicinity of the tank wall 17b of the electrolytic cell 10 on the opposite side of the electrolytic cell 10, and has a circulation means 30 for circulating the electrolytic solution 11. Therefore, since the electrolytic device 1 has such a circulation means 30, the electrolytic solution 11 can be circulated and the electrolytic solution 11 can be jetted in parallel with the electrode from the nozzle 33 toward the adjustment tank 20 side. The composition, concentration, pH, liquid temperature, etc. of the electrolytic solution 11 of the entire electrolytic device 1 can be made uniform. 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 from the nozzle 33 toward the adjustment tank 20 in parallel with the electrode, volatilization of the electrolyte solution 11 and scattering of mist can be suppressed. Deterioration of the surrounding environment in the device 1 can be prevented and safety can be ensured.

  Further, in the electrolysis apparatus 1, the above-described jet of the electrolyte solution 11 is supplied as a laminar flow to the interelectrode A and the gaps B and C between the electrode and the electrolytic cell wall by a plurality of multistage nozzles 33 in the circulation means 30. Therefore, the stagnation of the electrolytic solution 11 between the electrodes A and the gaps B and C between the electrodes and the electrolytic cell wall is eliminated, and 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 sometimes simply referred to as “hydroxide production method”), the indium hydroxide powder or hydroxide as described above. By using a tin powder electrolyzer, 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 FIGS. 1 and 2 is used will be described as an example.

  The method for producing hydroxide includes an electrolysis step for obtaining an electrolytic solution 11 (hereinafter referred to as “electrolytic slurry”) containing indium hydroxide powder or tin hydroxide powder, and solid-liquid separation of the electrolytic solution 11 from the electrolytic slurry. Electrolytic solution separation step, repulp washing step of adding electrolytic solution 11 to electrolytic slurry and repulp washing to obtain washing slurry, and dehydrating the washing solution from the obtained washing slurry to obtain indium hydroxide powder or tin hydroxide powder It has a washing liquid dehydration step 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 diameter affects the degree of aggregation, as a result, the width of the particle size distribution 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.

  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 the precipitate is formed with the concentration of the electrolytic solution 11 being non-uniform, so the width of the particle size distribution is wide. Therefore, the width of the particle size distribution 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 tin hydroxide powder is too fast and precipitates are formed with the concentration of the electrolytic solution 11 being non-uniform, so the width of the particle size distribution is wide. Therefore, the width of the particle size distribution 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 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 an increase in 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.

(Electrolyte flow rate)
The electrolyte flow rate per electrolytic cell 10 is preferably 0.007 L / min / A (battery current) to 0.03 L / min / A (battery current). In the case of less than 0.007 L / min / A (battery current), the nucleus growth has priority over the nucleus generation, and the particle diameter of the indium hydroxide powder or the tin hydroxide powder becomes large. On the other hand, when the electrolytic solution flow rate per electrolytic cell 10 exceeds 0.03 L / min / A (battery current), the environment around the electrolytic device 1 deteriorates due to volatilization of the electrolytic solution 11, scattering of mist, etc. There are safety issues.

  In addition, when the electrolytic solution flow rate per electrolytic cell 10 is 0.007 L / min / A (battery current) or more, the indium hydroxide powder or the tin hydroxide powder generated in the electrolytic solution 11 is not precipitated on the tank bottom 14. It is preferable to perform electrolysis in a suspended state.

(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.

  Further, in the electrolysis process, 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 31 through the liquid supply pipe 34 and the nozzle 33 into the electrolytic cell 10. Supply. In the electrolysis process, when supplying the electrolytic solution 11 into the electrolytic cell 10 by the circulation means 30, the electrolytic solution 11 is discharged from the plurality of nozzles 33 toward the adjustment tank 20 from the tank wall 17 b of the electrolytic cell 10. A set (laminar flow) of a plurality of jets of the electrolyte solution 11 is 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.

  In the electrolysis process, when the electrolytic solution 11 is supplied from the adjustment tank 20 into the electrolytic tank 10, the liquid level rises and overflows from the drain port 18, and the electrolytic solution 11 is returned to the adjustment tank 20.

  In the electrolysis process, the electrolytic solution 11 overflowed from the drain port 18 of the electrolytic cell 10 is adjusted in pH, liquid temperature, and the like in the adjustment tank 20, and the adjusted electrolytic solution 11 is supplied via the supply channel 31 by the circulation pump 32. Then, the electrolytic solution 10 is supplied again into the electrolytic cell 10, and this is continuously performed, whereby the electrolytic solution 11 is circulated in the electrolytic device 1 by the circulation means 30.

  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 11 is formed in the gaps B and C, and the electrolytic solution 11 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, which is not preferable.

  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 or the like as the electrolyte solution 11 component remains in the indium hydroxide powder or tin hydroxide powder, and the indium hydroxide powder or tin hydroxide powder There is an increased risk of fire when drying or when calcining indium hydroxide powder or tin hydroxide powder to obtain indium oxide powder or tin oxide powder. 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 cleaning liquid dehydration step, the electrolytic solution 11 adjusted by adding pure water is again put into the adjustment tank 20 and supplied to the electrolytic tank 10 through the supply flow path 31 by the circulation pump 32.

  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 11 is not discarded as waste liquid, the cost associated with waste liquid treatment can be reduced, and the loss of the electrolytic solution 11 can be suppressed. The load on the environment 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 the electrolytic solution 11 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 electrolysis apparatus 1 of the street.

  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 cell 10 and the adjustment tank 20 are connected by a supply channel 31, and the supply channel 31 is a liquid supply provided with a circulation pump 32 and a nozzle 33. Tube 34.

  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 arranged alternately so that both poles are parallel to each other and between the cathodes 13 and the anodes 12. The distance 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.

  In addition, as shown in FIG. 2, the electrolytic solution 11 is introduced into the electrolytic cell 10 in parallel with the gap between the anode 12 and the cathode 13 from the side of the cell wall 17 b of the electrolytic cell 10 on the opposite side of the adjustment tank 20. Three liquid supply pipes 34 provided with nozzles 33 that can be sprayed are provided in the depth direction of the electrolytic cell 10. As shown in FIG. 3, a nozzle 33 having a protruding tube constituted by a nozzle inner diameter D of 5 mm and a nozzle length L of 10 mm was used. Further, as shown in FIG. 2, a drain port 18 for overflowing the electrolyte solution 11 is disposed in the central portion of the upper part of the tank wall 17 a provided between the adjustment tank 20 and the electrolytic tank 10.

  Further, as shown in FIG. 2, 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 40 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 the electrolysis, the electrolytic solution 11 in the adjustment tank 20 is fed to the liquid supply pipe 34 through the supply flow path 31 by the circulation pump 32 at a speed of 20 L / min. It sprayed from the nozzle 33 provided in 34, and was sent to the electrolytic cell 10. FIG. In Example 1, when the supply rate of the electrolytic solution 11 was converted into the electrolytic solution flow rate per electrolytic cell 10, it was 0.015 L / min / A (battery current). Moreover, the electrolytic solution 11 in the electrolytic cell 10 is sent to the adjustment tank 20 by the overflow from the drain port 18 provided in the upper central part of the side wall 18b of the electrolytic cell 10, and the electrolytic cell 10 and the adjustment tank 20 are It circulates between.

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, an indium hydroxide cake 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 indium hydroxide cake obtained in the electrolytic solution separation process was washed. In the repulp washing step, pure water was added to the indium hydroxide cake, and the mixture was stirred in a stainless bucket container and redispersed. Next, in the repulp washing step, the solid-liquid separation operation was performed in the same manner as in the electrolytic solution separation step, and the indium hydroxide cake and the 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 via the supply flow path 31 by the circulation pump 32 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 indium hydroxide slurry was sampled, and the particle size distribution was measured by a laser diffraction / scattering method (SALD-2200, manufactured by Shimadzu Corporation).

(5) Drying process In Example 1, the indium hydroxide slurry obtained by the washing liquid dehydration process 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. 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, indium hydroxide powder was prepared in the same manner as in Example 1 except that the electrolytic solution flow rate per electrolytic cell 10 was 0.027 L / min / A (electrolytic solution speed: 36 L / min). Indium oxide powder was produced from the indium hydroxide powder. 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, indium hydroxide powder was prepared in the same manner as in Example 1 except that tin metal having a purity of 99.99% was used for the anode (anode) 12 and the pH of the electrolyte was adjusted to 7.0. And indium oxide powder was produced from the indium hydroxide powder. In Example 4, 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 5]
In Example 5, a tin hydroxide powder was produced in the same manner as in Example 4 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. 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, using 990 g of the indium oxide powder obtained in Example 1 and 10 g of the tin oxide powder obtained in Example 4, a compact was formed by a mixed cold press method. Next, in Example 6, the obtained molded body was sintered at 1400 ° C. for 30 hours in atmospheric pressure, and an indium oxide-tin oxide based sintered body was obtained. In Example 6, the relative density of the obtained sintered body was measured by the Archimedes method, and the results are shown in Table 3.

[Example 7]
In Example 7, using 990 g of the indium oxide powder obtained in Example 2 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 7, the obtained molded body was sintered at 1400 ° C. for 30 hours in the atmospheric pressure to obtain an indium oxide-tin oxide based sintered body. In Example 7, 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, indium hydroxide powder was prepared in the same manner as in Example 1 except that the electrolytic solution flow rate per electrolytic cell 10 was 0.005 L / min / A (electrolytic solution speed: 6 L / min). Indium oxide powder was prepared from the indium hydroxide powder. 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, indium hydroxide powder was prepared in the same manner as in Example 1 except that the electrolytic solution flow rate per electrolytic cell 10 was 0.050 L / min / A (electrolytic solution speed: 62 L / min). Indium oxide powder was prepared from the indium hydroxide powder. 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 3 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 3 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, a tin hydroxide powder was prepared in the same manner as in Example 3 except that the electrolytic solution flow rate per electrolytic cell 10 was 0.005 L / min / A (electrolytic solution speed: 6 L / min). Then, a tin oxide powder was produced from the tin hydroxide powder. 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 prepared in the same manner as in Example 3 except that the electrolytic solution flow rate per electrolytic cell 10 was 0.050 L / min / A (electrolytic solution speed: 62 L / min). Then, a tin oxide powder was produced from the tin hydroxide powder. 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 Example 1 and Example 2, the minimum diameter is 0.3 μm and the maximum diameter is 1.1 μm. In Example 3, the minimum diameter is 0.3 μm and the maximum diameter is 1 μm. It was found that indium hydroxide powder having a very narrow particle size distribution of 0.0 μm was 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, the electrolyte flow rate per electrolytic cell 10 is 0.005 L / min / A (tank Current). As a result, as shown in Table 1, it was found that in Comparative Examples 1 to 3, indium hydroxide powder having a wide particle size distribution was obtained.

  Moreover, in the comparative example 4, it electrolyzed by the electrolyte solution flow volume per electrolytic cell 10 0.050L / min / A (battery current). 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 Example 4 and Example 5, tin hydroxide powder having a very narrow particle size distribution with a minimum diameter of 0.3 μm and a maximum diameter of 3.3 μm was obtained. .

  On the other hand, in Comparative Example 5 and Comparative Example 6, the adjustment tank 20 is not used and electrolysis is performed only in the electrolytic tank 10, and in Comparative Example 7, the electrolytic solution flow rate per electrolytic tank 10 is 0.005 L / min / A (tank Current). As a result, as shown in Table 2, in Comparative Examples 5 to 7, it was found that tin hydroxide powder having a wide particle size distribution was obtained.

  Moreover, in Comparative Example 8, electrolysis was performed at an electrolytic solution flow rate per electrolytic cell 10 of 0.050 L / min / A (battery current). 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 6 and Example 7, an extremely 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 low relative density was obtained.

  From the results of Examples 1 to 7 and Comparative Examples 1 to 10, by using the electrolysis apparatus 1 having the circulation means 30, the indium hydroxide powder has excellent particle size uniformity and a narrow particle size distribution. Alternatively, tin hydroxide powder can be obtained. 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, 17c, 17d Tank wall, 18 Drainage port 20 adjustment tank, 21 stirring rod, 22 pH electrode, 23 heater, 24 cooler, 25 chemical tank, 26 metering pump, 27 tank bottom, 28 liquid inlet, 30 circulation means, 31 supply flow path, 32 circulation pump, 33 nozzles, 34 supply pipes, A electrodes, B and C gaps, D nozzle inner diameter, L nozzle length

Claims (9)

An electrolysis device for producing indium hydroxide powder or tin hydroxide powder by electrolyzing indium or tin,
An electrolytic cell provided with a plurality of electrodes;
An adjustment tank for adjusting the electrolyte,
A plurality of nozzles connected to the electrolytic tank and the adjustment tank and supplying the electrolytic solution into the electrolytic tank are provided in the vicinity of the tank wall opposite to the adjustment tank of the electrolytic tank to circulate the electrolytic solution. Circulation means ,
At the upper end of the tank wall provided between the electrolytic cell and the adjustment tank, it has a drain outlet for overflowing the electrolytic solution from the electrolytic cell to the adjustment tank ,
The circulating means jets the electrolytic solution parallel to the electrode from the nozzle toward the adjustment tank, and is an indium hydroxide powder or tin hydroxide powder electrolyzer.   2. The electrolysis apparatus for indium hydroxide powder or tin hydroxide powder according to claim 1, wherein the nozzle is provided to face between the electrodes.   3. The electrolytic apparatus for indium hydroxide powder or tin hydroxide powder according to claim 1 or 2, wherein the nozzle is provided in multiple stages. The indium hydroxide powder or tin hydroxide powder electrolyzer 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. The method for producing indium hydroxide powder or tin hydroxide powder according to claim 5 , wherein the flow rate of the electrolytic solution per electrolytic cell is 0.007 L / min / A to 0.03 L / min / A. 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 or claim 6, 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 or claim 6, 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 8. A method for producing a sputtering target, comprising:

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