Method for producing copper oxide

Abstract

To provide a method for producing copper oxide, capable of reducing the amount of an alkali metal carbonate used and reducing the total amount of alkali used in terms of the amount of alkali metal ions.SOLUTION: The method for producing copper oxide includes: a step A of subjecting a copper salt aqueous solution to alkali treatment to obtain a basic copper carbonate slurry; and a step B of obtaining a copper oxide slurry from the obtained basic copper carbonate slurry. The ratio of the number of moles of an alkali metal hydroxide used in the step A to the number of moles of an alkali metal carbonate used in the step A is greater than 1.20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing copper oxide. [Background technology]

[0002] Copper plating technology is used in many electronics-related products, including printed circuit board wiring, printing rolls, electrolytic foils, wire rods, etc. Accordingly, there is a demand for technology related to the production of copper oxide used in copper plating solutions.

[0003] For example, Patent Document 1 discloses an easily soluble cupric oxide powder having an average particle size of 15 μm to 45 μm, an angle of repose of 50° or less, and a CuO content of 97.0% by weight or more. Patent Document 1 also discloses a method for producing the above cupric oxide powder, which uses basic copper carbonate as a raw material and obtains the cupric oxide by treating the basic copper carbonate with an alkali. Patent Document 1 also describes that its object is to provide cupric oxide that is suitable for use in copper plating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-143737 A Summary of the Invention [Problem to be solved by the invention]

[0005] When copper oxide is produced using copper chloride as a raw material, for example, copper chloride is first treated with an alkali to obtain a basic copper carbonate slurry, and the obtained basic copper carbonate slurry can be further treated in the slurry state to obtain copper oxide. When copper oxide is produced in this manner using copper chloride as a raw material, it is desirable to reduce the amount of alkaline component used while allowing the reaction of copper chloride to produce basic copper carbonate to proceed appropriately.

[0006] The present invention provides a method for producing copper oxide, which can reduce the amount of alkali metal carbonate used and further reduce the total amount of alkali used in terms of the amount of alkali metal ions. [Means for solving the problem]

[0007] According to the present invention, there is provided a method for producing copper oxide as follows.

[0008] 1. A step A of treating an aqueous copper salt solution with an alkali to obtain a basic copper carbonate slurry; A step B of obtaining a copper oxide slurry from the obtained basic copper carbonate slurry; A method for producing copper oxide comprising the steps of: A method for producing copper oxide, wherein the ratio of the number of moles of the alkali metal hydroxide used in the step A to the number of moles of the alkali metal carbonate used in the step A exceeds 1.20. 2. In the method for producing copper oxide according to 1., The method for producing copper oxide, wherein the aqueous copper salt solution contains copper chloride. 3. In the method for producing copper oxide according to 1. or 2., The method for producing copper oxide, wherein the alkali metal carbonate comprises sodium carbonate. 4. In the method for producing copper oxide according to any one of 1. to 3., The method for producing copper oxide, wherein the alkali metal hydroxide comprises sodium hydroxide. 5. A method for producing copper oxide according to any one of 1. to 4., comprising the steps of: The method for producing copper oxide, wherein the pH in the reaction tank in step A is 6.0 or more and 10.0 or less. 6. A method for producing copper oxide according to any one of 1. to 5., The method for producing copper oxide, wherein the temperature in the reaction tank in step A is 25°C or higher and 95°C or lower. 7. A method for producing copper oxide according to any one of 1. to 6., In the step A, the copper salt aqueous solution and the alkaline aqueous solution are simultaneously supplied into a reaction vessel. 8. The method for producing copper oxide according to 7., A method for producing copper oxide, wherein in the step A, the pH in the reaction tank is adjusted to 6.0 or more and 10.0 or less by adjusting the amount of the aqueous alkaline solution supplied per hour. 9. A method for producing copper oxide according to any one of 1. to 8., The method for producing copper oxide, wherein the pH in the reaction tank in step B is 9.0 or higher. 10. A method for producing copper oxide according to any one of 1. to 9., The method for producing copper oxide, wherein the temperature in the reaction tank in step B is 45°C or higher and 95°C or lower. Effect of the Invention

[0009] According to the present invention, it is possible to provide a method for producing copper oxide that can reduce the amount of alkali metal carbonate used and further reduce the total amount of alkali used in terms of the amount of alkali metal ions. [Brief description of the drawings]

[0010] [Figure 1] 1 is a flowchart showing an example of a method for producing copper oxide according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a schematic diagram showing an example of a method for producing copper oxide according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the method for producing copper oxide according to the present invention will be described.

[0012] The method for producing copper oxide according to this embodiment includes step A of obtaining a basic copper carbonate slurry by alkali-treating an aqueous copper salt solution, and step B of obtaining a copper oxide slurry from the obtained basic copper carbonate slurry, in which the ratio of the number of moles of the alkali metal hydroxide used in step A to the number of moles of the alkali metal carbonate used in step A exceeds 1.20.

[0013] Basic copper carbonate is a divalent copper ion, Cu2+ and carbonate ion CO3 2- and hydroxide ion OH - The composition of the basic copper carbonate according to this embodiment is not particularly limited, but may include, for example, one or two selected from the group consisting of dicopper(II) carbonate dihydroxide, Cu2(OH)2(CO3), and tricopper(II) bis(carbonate) dihydroxide, Cu3(OH)2(CO3)2, and preferably dicopper(II) carbonate dihydroxide, Cu2(OH)2CO3.

[0014] Basic copper carbonate is, for example, a copper ion, Cu 2+ In a solution containing carbonate ions CO3 2- The resulting solution is obtained by adding an aqueous alkaline solution containing

[0015] For example, when copper chloride is used as the copper ion source and sodium carbonate is used as the alkali, the reaction to produce basic copper carbonate proceeds as shown in the following reaction formula (1). 2Na2CO3+2CuCl2+H2O→CuCO3·Cu(OH)2+4NaCl+CO2↑···(1)

[0016] In addition, when copper chloride is used as the copper ion source and sodium carbonate and sodium hydroxide are used together as the alkali, the reaction to produce basic copper carbonate proceeds as shown in the following reaction formula (2). When the reaction to produce basic copper carbonate proceeds as shown in reaction formula (2), the carbon dioxide produced by the reaction of copper chloride and sodium carbonate reacts with sodium hydroxide to produce sodium carbonate again. Therefore, the amount of sodium carbonate used can be reduced. Na2CO3+2NaOH+2CuCl2→CuCO3·Cu(OH)2+4NaCl···(2)

[0017] The present inventors have found that, by setting the ratio of the number of moles of alkali metal hydroxide to the number of moles of alkali metal carbonate to be equal to or greater than a certain level, it is possible to reduce the amount of alkali metal carbonate used and further reduce the total amount of alkali used while still allowing the reaction to obtain basic copper carbonate to proceed appropriately. The total amount of alkali used in the present invention means the sum of the number of moles of alkali metal ions in the alkali metal carbonate and the number of moles of alkali metal ions in the alkali metal hydroxide used in the copper oxide production method according to this embodiment, i.e., the total amount of alkali used in the present invention means the total amount of alkali used in terms of the amount of alkali metal ions. When the ratio of the number of moles of alkali metal hydroxide to the number of moles of alkali metal carbonate is equal to or greater than a certain level, the reaction proceeds as shown in reaction formula (2), and it is believed that the reaction to obtain basic copper carbonate can proceed appropriately while reducing the amount of alkali metal carbonate used, and thus the total amount of alkali used in terms of the amount of alkali metal ions.

[0018] The ratio of the number of moles of the alkali metal hydroxide used in step A to the number of moles of the alkali metal carbonate used in step A is preferably greater than 1.25, more preferably greater than 1.30, even more preferably greater than 1.35, even more preferably greater than 1.40, even more preferably greater than 1.45, even more preferably greater than 1.50, even more preferably greater than 1.55, even more preferably greater than 1.60, even more preferably greater than 1.70, even more preferably greater than 1.80, and even more preferably greater than 1.90. This allows the amount of alkali metal carbonate used to be further reduced. If the amount of alkali metal carbonate used can be reduced, the total amount of alkali used, calculated as the amount of alkali metal ions, can be further reduced. Furthermore, if the amount of alkali metal carbonate used can be further reduced, the amount of carbon dioxide gas and / or carbonate ions generated by the reaction of the alkali metal carbonate can be reduced, which is preferable from the viewpoint of protecting the global environment. In addition, since an alkali metal carbonate is generally dissolved in water or the like before use in a reaction, if the amount of alkali metal carbonate used can be further reduced, the frequency of dissolution work can be reduced, which is preferable from the viewpoint of improving production efficiency.

[0019] The ratio of the number of moles of the alkali metal hydroxide used in step A to the number of moles of the alkali metal carbonate used in step A is preferably less than 3.00, more preferably less than 2.50, even more preferably less than 2.20, even more preferably less than 2.00, even more preferably less than 1.90, even more preferably less than 1.80, even more preferably less than 1.70, even more preferably less than 1.60, even more preferably less than 1.55, even more preferably less than 1.50, even more preferably less than 1.45, and even more preferably less than 1.40. This reduces the amount of impurities such as chlorine contained in the copper oxide. This also makes it possible to suppress the particle size of the copper oxide from becoming finer. From the viewpoint of improving handleability, it is preferable not to make the particle size of the copper oxide finer than necessary.

[0020] The ratio of the number of moles of the alkali metal hydroxide used in step A to the number of moles of the alkali metal carbonate used in step A is preferably more than 1.20 and less than 1.45, or more than 1.50 and less than 3.00, more preferably more than 1.25 and less than 1.45, or more than 1.60 and less than 2.50, even more preferably more than 1.30 and less than 1.45, or more than 1.70 and less than 2.20, and even more preferably more than 1.30 and less than 1.40, or more than 1.80 and less than 2.00. This makes it possible to further reduce the total amount of alkali used in terms of the amount of alkali metal ions, reduce the amount of impurities such as chlorine contained in the copper oxide, and further suppress the grain size of the copper oxide from being refined.

[0021] 1 is a flowchart showing an example of a method for producing copper oxide according to the present embodiment. Hereinafter, the method for producing copper oxide according to the present embodiment will be described with reference to the flowchart in FIG. First, an aqueous copper salt solution and an aqueous alkali solution are fed into a reaction vessel, and the aqueous copper salt solution is subjected to an alkali treatment in the reaction vessel to obtain a basic copper carbonate slurry. The resulting basic copper carbonate slurry is then washed. Next, the washed basic copper carbonate slurry and an alkaline aqueous solution are fed into a reaction vessel, and then aged for a certain period of time to obtain a copper oxide slurry. The resulting copper oxide slurry is then washed, dehydrated and dried to obtain copper oxide powder.

[0022] FIG. 2 is a schematic diagram showing an example of a method for producing copper oxide according to this embodiment.

[0023] According to the manufacturing method shown in the schematic diagram of FIG. 2, first, ion-exchanged water serving as a diluent (not shown) is placed in a reaction vessel 101 . Next, the copper salt aqueous solution from the copper salt aqueous solution storage tank 102 and the alkaline aqueous solution from the alkaline aqueous solution storage tank 103 are supplied to the reaction tank 101, and the copper salt aqueous solution is subjected to an alkaline treatment in the reaction tank 101 to obtain a basic copper carbonate slurry. The supply amount of the copper salt aqueous solution can be controlled by a supply amount control device 112. The supply amount of the alkaline aqueous solution can be controlled by a supply amount control device 113. The resulting basic copper carbonate slurry is then fed to the washing tank 104 for washing. Next, the washed basic copper carbonate slurry from the washing tank 104 and the alkaline aqueous solution from the alkaline aqueous solution storage tank 105 are fed into the reaction tank 106, and then aged for a certain period of time to obtain copper oxide slurry. The amount of the alkaline aqueous solution fed can be controlled by a feed amount control device 115. The resulting copper oxide slurry is then fed to a washing tank 107 for washing, fed to a centrifuge 108 for dehydration, and fed to a dryer 109 for drying, to obtain copper oxide powder.

[0024] Hereinafter, each step of the method for producing copper oxide according to this embodiment will be described.

[0025] <Process A> The method for producing copper oxide according to this embodiment includes a step A of treating an aqueous copper salt solution with an alkali to obtain a basic copper carbonate slurry.

[0026] The method of the alkaline treatment in step A is not particularly limited, and the treatment may be performed using a solid alkaline component or an aqueous solution containing an alkaline component (alkaline aqueous solution). From the viewpoint of improving the handleability of the alkaline treatment, however, it is preferable to perform the treatment with an alkaline aqueous solution.

[0027] In step A, it is preferable to supply an aqueous copper salt solution and an aqueous alkaline solution to a reaction vessel 101 containing a diluent (not shown), and to stir the contents of the reaction vessel 101 with a stirring blade 111 .

[0028] The diluent serves as a buffer to suppress abrupt changes in pH and temperature due to the reaction by diluting the reaction solution in the reaction tank 101. As the diluent, for example, water such as ion-exchanged water can be used.

[0029] The diluent may contain a water-soluble solvent, for example, one or two selected from the group consisting of alcohols such as methanol, ethanol, and isopropanol, acetone, alkylamines such as ethylamine and trimethylamine, glycerin, and polyethylene glycol.

[0030] The copper salt aqueous solution according to this embodiment contains a copper salt and water.

[0031] The copper salt according to the present embodiment is not particularly limited, and may be any salt containing copper ions.The copper salt according to the present embodiment includes, for example, one or more selected from the group consisting of copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, copper cyanide and copper hydroxide, preferably one or two selected from the group consisting of copper chloride and copper sulfate, more preferably copper chloride.

[0032] The copper salt aqueous solution according to the present embodiment may be an aqueous solution prepared by dissolving the above-mentioned copper salt in water, or may be a copper chloride waste liquid, a copper sulfate waste liquid, a copper nitrate waste liquid, or the like, which is an etching waste liquid from electronic circuit boards such as printed circuit boards.

[0033] The aqueous copper salt solution according to this embodiment may contain a water-soluble solvent, for example, those listed as water-soluble solvents that may be contained in the diluent.

[0034] The copper salt aqueous solution according to this embodiment may contain an acid, for example, hydrochloric acid, in order to suppress precipitation of the copper salt.

[0035] From the viewpoint of improving the reaction efficiency, the content of copper ions in the aqueous copper salt solution according to this embodiment is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, even more preferably 7% by mass or more, even more preferably 9% by mass or more, and is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less.

[0036] The alkaline aqueous solution used in step A contains an alkaline component and water. As the alkaline component, an alkali metal carbonate and / or an alkali metal hydroxide can be used.

[0037] The alkali metal carbonate according to the present embodiment is not particularly limited, but includes, for example, one or two selected from the group consisting of sodium carbonate, lithium carbonate, potassium carbonate, magnesium carbonate, and calcium carbonate, and preferably includes sodium carbonate.

[0038] The alkali metal hydroxide according to the present embodiment is not particularly limited, but includes, for example, one or more selected from the group consisting of sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide, and preferably includes sodium hydroxide.

[0039] The aqueous alkaline solution used in step A may contain a water-soluble solvent, and as the water-soluble solvent, those listed as the water-soluble solvent that may be contained in the aqueous copper salt solution can be used.

[0040] In the step A, a plurality of kinds of aqueous alkaline solutions may be supplied in a plurality of stages. For example, an aqueous alkaline solution A1 may be supplied, and then an aqueous alkaline solution A2 having a higher pH than the aqueous alkaline solution A1 may be supplied.

[0041] From the viewpoint of adjusting the pH in reaction tank 101 to the desired range, the pH of the alkaline aqueous solution used in step A is preferably 7.0 or more, more preferably 7.5 or more, even more preferably 8.0 or more, even more preferably 8.5 or more, even more preferably 9.0 or more, even more preferably 9.5 or more, even more preferably 10.0 or more, even more preferably 10.5 or more, even more preferably 11.0 or more, even more preferably 11.5 or more, even more preferably 12.0 or more, even more preferably 12.5 or more, even more preferably 13.0 or more, even more preferably 13.3 or more, and is, for example, 14.0 or less, preferably 13.8 or less.

[0042] The content of alkali metal carbonate in the alkaline aqueous solution used in step A is, from the viewpoint of adjusting the pH in reaction tank 101 to the desired range, preferably 1 mass% or more, more preferably 3 mass% or more, even more preferably 5 mass% or more, even more preferably 7 mass% or more, even more preferably 8 mass% or more, and preferably 20 mass% or less, more preferably 18 mass% or less, even more preferably 16 mass% or less, even more preferably 14 mass% or less, and even more preferably 12 mass% or less.

[0043] The content of alkali metal carbonate in the alkaline aqueous solution used in step A is, from the viewpoint of adjusting the pH in reaction tank 101 to the desired range, preferably 0.1 mol / L or more, more preferably 0.3 mol / L or more, even more preferably 0.5 mol / L or more, even more preferably 0.7 mol / L or more, even more preferably 0.9 mol / L or more, and is, for example, 10 mol / L or less, preferably 8 mol / L or less, more preferably 6 mol / L or less, even more preferably 4 mol / L or less, even more preferably 2 mol / L or less, and even more preferably 1.5 mol / L or less.

[0044] The content of alkali metal hydroxide in the alkaline aqueous solution used in step A is, from the viewpoint of adjusting the pH in reaction tank 101 to the desired range, preferably 1 mass% or more, more preferably 3 mass% or more, even more preferably 5 mass% or more, and even more preferably 6 mass% or more, and is preferably 20 mass% or less, more preferably 15 mass% or less, even more preferably 13 mass% or less, even more preferably 11 mass% or less, even more preferably 9 mass% or less, and even more preferably 7 mass% or less.

[0045] From the viewpoint of adjusting the pH in the reaction tank 101 to the desired range, the content of the alkali metal hydroxide in the alkaline aqueous solution used in step A is preferably 0.1 mol / L or more, more preferably 0.2 mol / L or more, even more preferably 0.4 mol / L or more, even more preferably 0.6 mol / L or more, even more preferably 0.8 mol / L or more, even more preferably 1.0 mol / L or more, even more preferably 1.2 mol / L or more, even more preferably 1.4 mol / L or more, even more preferably 1.6 mol / L or more, even more preferably 1.7 mol / L or more, and is, for example, 10 mol / L or less, preferably 8 mol / L or less, more preferably 6 mol / L or less, even more preferably 4 mol / L or less, even more preferably 2 mol / L or less, and even more preferably 1.8 mol / L or less.

[0046] In the step A, it is preferable to simultaneously supply the aqueous copper salt solution and the aqueous alkaline solution into the reaction vessel.

[0047] When the copper salt aqueous solution and the alkaline aqueous solution are supplied simultaneously to the reaction tank, the copper salt aqueous solution and the alkaline aqueous solution may be mixed in advance and supplied to the reaction tank from one supply route, or each may be supplied to the reaction tank from a different supply route. Figure 2 shows an example in which the copper salt aqueous solution and the alkaline aqueous solution are supplied from different supply routes. From the viewpoint of easily controlling the supply amounts of the copper salt aqueous solution and the alkaline aqueous solution individually, it is preferable to supply the copper salt aqueous solution and the alkaline aqueous solution through separate supply routes.

[0048] In step A, it is preferable to adjust the pH in the reaction tank 101 to a certain range by adjusting the amount of the alkaline aqueous solution supplied per hour. Specifically, when the pH in the reaction tank 101 approaches the upper limit of the following range, the supply amount control device 113 may reduce the amount of the alkaline aqueous solution supplied per hour from the alkaline aqueous solution storage tank 103, and when the pH in the reaction tank 101 approaches the lower limit of the following range, the supply amount control device 113 may increase the amount of the alkaline aqueous solution supplied per hour from the alkaline aqueous solution storage tank 103.

[0049] From the viewpoint of improving the reaction efficiency, the pH in the reaction tank 101 in step A is preferably 6.0 or more, more preferably 6.5 or more, even more preferably 7.0 or more, even more preferably 7.2 or more, and is preferably 10.0 or less, more preferably 9.5 or less, even more preferably 9.0 or less, even more preferably 8.5 or less, even more preferably 8.0 or less, even more preferably 7.8 or less.

[0050] In step A, the supply amount of the aqueous alkaline solution per hour is adjusted to adjust the pH in the reaction tank 101 to preferably 6.0 or more, more preferably 6.5 or more, even more preferably 7.0 or more, even more preferably 7.2 or more, and preferably 10.0 or less, more preferably 9.5 or less, even more preferably 9.0 or less, even more preferably 8.5 or less, even more preferably 8.0 or less, even more preferably 7.8 or less.

[0051] The temperature in reaction tank 101 in step A is preferably 25°C or higher, more preferably 35°C or higher, even more preferably 45°C or higher, even more preferably 55°C or higher, and even more preferably 60°C or higher, from the viewpoint of improving the reaction efficiency, and is preferably 95°C or lower, more preferably 85°C or lower, even more preferably 75°C or lower, and even more preferably 70°C or lower, from the viewpoint of suppressing side reactions.

[0052] The basic copper carbonate slurry obtained through step A may be used for the synthesis of copper oxide in an unwashed state, or may be used for the synthesis of copper oxide after being subjected to a washing step.

[0053] In the washing step, for example, a basic copper carbonate slurry is supplied to the washing tank 104, the basic copper carbonate is precipitated, the supernatant liquid is removed, ion-exchanged water is supplied, and washing can be performed by stirring with the stirring blade 111.

[0054] Alternatively, after centrifuging the basic copper carbonate slurry, the solid content may be supplied to the washing tank 104, ion-exchanged water may be supplied, and the solid content may be stirred with the stirring blades 111 to perform washing.

[0055] The temperature in the cleaning tank is preferably 20° C. or higher and 90° C. or lower, more preferably 40° C. or higher and 70° C. or lower, so that impurities can be removed more easily.

[0056] The number of washing steps is not particularly limited, and may be repeated until the basic copper carbonate has a desired purity.

[0057] <Process B> The method for producing copper oxide according to this embodiment includes a step B of obtaining a copper oxide slurry from the obtained basic copper carbonate slurry.

[0058] From the viewpoint of improving the reaction efficiency, the pH in the reaction tank 106 in step B is preferably 9.0 or more, more preferably 9.5 or more, even more preferably 10.0 or more, even more preferably 10.5 or more, even more preferably 11.0 or more, and is, for example, 14.0 or less, preferably 13.5 or less.

[0059] The method for adjusting the pH in the reaction tank 106 in step B is not particularly limited. For example, the pH in the reaction tank 106 can be adjusted by supplying an alkaline component into the reaction tank 106. As for the alkaline component, a solid alkaline component may be used for treatment, or an aqueous solution containing the alkaline component (alkaline aqueous solution) may be used for treatment. From the viewpoint of improving the handling properties of the pH adjustment, however, treatment with an alkaline aqueous solution is preferred. As the alkaline aqueous solution, the same alkaline aqueous solution as that used in step A can be used.

[0060] From the viewpoint of improving the reaction efficiency, the temperature in the reaction tank 106 in step B is preferably 45°C or higher, more preferably 50°C or higher, even more preferably 55°C or higher, even more preferably 60°C or higher, even more preferably 65°C or higher, even more preferably 70°C or higher, even more preferably 75°C or higher, and is, for example, 95°C or lower, preferably 90°C or lower, more preferably 85°C or lower.

[0061] The maturation time in the reaction tank 106 in step B is preferably 30 minutes or more, more preferably 60 minutes or more, and even more preferably 90 minutes or more, from the viewpoint of improving the reaction efficiency.

[0062] The copper oxide slurry obtained through step B may be washed, dehydrated, and further dried to obtain a powder. These unit operations can be carried out using commonly used methods and equipment.

[0063] The copper oxide can be washed using the same process as described for washing basic copper carbonate.

[0064] The dehydration means in the dehydration step is not particularly limited. For example, the washed copper oxide slurry may be dehydrated using a centrifuge 108 or by suction filtration.

[0065] In the drying step, for example, the copper oxide cake obtained in the dehydration step is dried in a dryer 109 such as a box dryer or a continuous dryer. The drying temperature is not particularly limited, but from the viewpoint of removing moisture while suppressing the deterioration of the copper oxide, it is preferably 60° C. or higher, more preferably 70° C. or higher and even more preferably 80° C. or higher, and from the viewpoint of preventing the denaturation of the copper oxide, it is preferably 150° C. or lower, more preferably 120° C. or lower, and more preferably 100° C. or lower.

[0066] The use of the copper oxide according to this embodiment is not particularly limited, but it can be used, for example, as a raw material for agricultural chemicals, plating solutions, and the like.

[0067] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included in the present invention. EXAMPLES

[0068] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, the examples were tested at 23° C. and a relative humidity of 50%.

[0069] [Example 1] <Process A> Different aqueous alkaline solutions were used in the first and second halves of step A in Example 1. Hereinafter, the aqueous alkaline solution used in the first half will be referred to as aqueous alkaline solution A1, and the aqueous alkaline solution used in the second half will be referred to as aqueous alkaline solution A2.

[0070] (1) First half of process A First, 2.1 L of ion-exchanged water was placed in a reaction vessel, stirred, and heated to 65°C.

[0071] Next, while stirring the inside of the reaction tank, the aqueous copper salt solution 1 and the aqueous alkali solution A1 were simultaneously supplied under the conditions shown in Table 1, and the first half of step A was started.

[0072] In the first half of the step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of the aqueous alkaline solution A1 supplied.

[0073] The copper salt aqueous solution 1 was prepared by dissolving copper(II) chloride dihydrate (manufactured by Ikoma Pharmaceutical Co., Ltd.) in ion-exchanged water, and further adding hydrochloric acid so that the content of chloride ions derived from hydrochloric acid was 1.0 mass %. The alkaline aqueous solution A1 was prepared by dissolving sodium carbonate (light ash (industrial use), manufactured by Tokuyama Corporation) in ion-exchanged water.

[0074] [Table 1]

[0075] (2) The second half of Process A After 135 minutes had elapsed from the start of the first half of step A, the supply of the alkaline aqueous solution A1 was stopped, the supply amount per unit time of the copper salt aqueous solution 1 was changed according to the conditions shown in Table 2, and further the supply of the alkaline aqueous solution A2 was started according to the conditions shown in Table 2, and the second half of step A was started.

[0076] In the latter half of step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A2 supplied.

[0077] The alkaline aqueous solution A2 was prepared by dissolving sodium carbonate (light ash (industrial use) manufactured by Tokuyama Corporation) and liquid caustic soda (manufactured by Kaneka Corporation) in ion-exchanged water.

[0078] After 345 minutes had elapsed from the start of the second half of step A, the supply of the aqueous copper salt solution 1 and the aqueous alkaline solution A2 was stopped, and step A was terminated.

[0079] [Table 2]

[0080] The amount of the alkaline component used in step A of Example 1 is as shown in Table 3. [Table 3]

[0081] <Process B> The basic copper carbonate slurry obtained by the above method was fed into a reaction tank, the temperature inside the reaction tank was adjusted to 80°C, an aqueous sodium hydroxide solution was further fed into the reaction tank to adjust the pH inside the reaction tank to 11.0, and the mixture was aged for 2 hours to obtain a copper oxide slurry. Next, the copper oxide slurry produced in the reaction tank was washed with ion-exchanged water, dehydrated by suction filtration, and further dried in a dryer to obtain powdered copper oxide.

[0082] [Example 2] <Process A> The same aqueous alkaline solution was used throughout the first and second halves of step A in Example 2. Hereinafter, the aqueous alkaline solution used in step A in Example 2 will be referred to as aqueous alkaline solution A3.

[0083] (1) First half of process A First, 2.1 L of ion-exchanged water was placed in a reaction vessel, stirred, and heated to 65°C.

[0084] Next, while stirring the inside of the reaction tank, the aqueous copper salt solution 1 and the aqueous alkaline solution A3 were simultaneously supplied under the conditions shown in Table 4, and the first half of step A was started.

[0085] In the first half of the step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A3 supplied.

[0086] The alkaline aqueous solution A3 was prepared by dissolving sodium carbonate (light ash (industrial use) manufactured by Tokuyama Corporation) and liquid caustic soda (manufactured by Kaneka Corporation) in ion-exchanged water.

[0087] [Table 4]

[0088] (2) The second half of Process A After 135 minutes had elapsed from the start of the first half of step A, the supply amounts per unit time of the aqueous copper salt solution 1 and the aqueous alkaline solution A3 were changed to the conditions shown in Table 5, and the second half of step A was started.

[0089] In the latter half of step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A3 supplied.

[0090] After 345 minutes had elapsed from the start of the second half of step A, the supply of the aqueous copper salt solution 1 and the aqueous alkaline solution A3 was stopped, and step A was terminated.

[0091] [Table 5]

[0092] The amount of the alkaline component used in step A of Example 2 is as shown in Table 6.

[0093] [Table 6]

[0094] <Process B> Powdered copper oxide was obtained in the same manner as in Example 1 using the basic copper carbonate slurry obtained above.

[0095] [Comparative Example 1] <Process A> The same aqueous alkaline solution was used throughout the first and second halves of step A in Comparative Example 1. Hereinafter, the aqueous alkaline solution used in step A in Comparative Example 1 will be referred to as aqueous alkaline solution A4.

[0096] (1) First half of process A First, 2.1 L of ion-exchanged water was placed in a reaction vessel, stirred, and heated to 65°C.

[0097] Next, while stirring the inside of the reaction tank, the aqueous copper salt solution 1 and the aqueous alkaline solution A4 were simultaneously supplied under the conditions shown in Table 7, and the first half of step A was started.

[0098] In the first half of step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A4 supplied.

[0099] The alkaline aqueous solution A4 was prepared by dissolving sodium carbonate (light ash (industrial use), manufactured by Tokuyama Corporation) in ion-exchanged water.

[0100] [Table 7]

[0101] (2) The second half of Process A After 135 minutes had elapsed from the start of the first half of step A, the supply amounts per unit time of the aqueous copper salt solution 1 and the aqueous alkaline solution A4 were changed to the conditions shown in Table 8, and the second half of step A was started.

[0102] In the latter half of step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A4 supplied.

[0103] After 345 minutes had elapsed from the start of the second half of step A, the supply of the aqueous copper salt solution 1 and the aqueous alkaline solution A4 was stopped, and step A was terminated.

[0104] [Table 8]

[0105] The amount of the alkali component used in step A of Comparative Example 1 is as shown in Table 9.

[0106] [Table 9]

[0107] <Process B> Powdered copper oxide was obtained in the same manner as in Example 1 using the basic copper carbonate slurry obtained above.

[0108] [Comparative Example 2] <Process A> The same aqueous alkaline solution was used throughout the first and second halves of step A in Comparative Example 2. Hereinafter, the aqueous alkaline solution used in step A in Comparative Example 2 will be referred to as aqueous alkaline solution A5.

[0109] (1) First half of process A First, 2.1 L of ion-exchanged water was placed in a reaction vessel, stirred, and heated to 65°C.

[0110] Next, while stirring the inside of the reaction tank, the aqueous copper salt solution 12 and the aqueous alkaline solution A5 were simultaneously supplied under the conditions shown in Table 10, and the first half of step A was started.

[0111] In the first half of step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A5 supplied.

[0112] The alkaline aqueous solution A5 was prepared by dissolving sodium carbonate (light ash (industrial use) manufactured by Tokuyama Corporation) and liquid caustic soda (manufactured by Kaneka Corporation) in ion-exchanged water.

[0113] [Table 10]

[0114] (2) The second half of Process A After 135 minutes had elapsed from the start of the first half of step A, the supply amounts per unit time of the aqueous copper salt solution 2 and the aqueous alkaline solution A5 were changed to the conditions shown in Table 11, and the second half of step A was started.

[0115] In the latter half of step A, the pH and temperature in the reaction tank were maintained at 7.5 and 65° C., respectively, by adjusting the amount of aqueous alkaline solution A5 supplied.

[0116] After 345 minutes had elapsed from the start of the second half of step A, the supply of the aqueous copper salt solution 1 and the aqueous alkaline solution A5 was stopped, and step A was terminated.

[0117] [Table 11]

[0118] The amount of the alkaline component used in step A of Comparative Example 2 is as shown in Table 12.

[0119] [Table 12]

[0120] <Process B> Powdered copper oxide was obtained in the same manner as in Example 1 using the basic copper carbonate slurry obtained above.

[0121] The total amounts of the alkaline components used in step A in Examples 1 and 2 and Comparative Examples 1 and 2 are summarized in Table 13.

[0122] The copper oxide obtained by the above method was analyzed by spectrophotometry. The chlorine content in the copper oxide obtained by analysis is shown in Table 13.

[0123] The volume-average median diameter D of the copper oxide obtained by the above method is 50 was measured using a particle size distribution analyzer (Microtrack Bell MT3300EXII). The results are shown in Table 13.

[0124] [Table 13]

[0125] The production methods of Examples 1 and 2 were able to reduce the total amount of alkali used, calculated as the amount of alkali metal ions, compared to Comparative Examples 1 and 2. This shows that the copper oxide production method according to this embodiment makes it possible to produce copper oxide while reducing the total amount of alkali used, calculated as the amount of alkali metal ions.

[0126] Furthermore, when Example 1 is compared with Example 2, the chlorine content in the copper oxide is lower and the particle size is suppressed in Example 1. This shows that there is a tendency for the chlorine content to be reduced and the particle size to be suppressed by reducing the ratio of the number of moles of the alkali metal hydroxide to the number of moles of the alkali metal carbonate. [Explanation of symbols]

[0127] 101 Reactor 102 Copper salt aqueous solution storage tank 103 Alkaline aqueous solution storage tank 104 Cleaning tank 105 Alkaline aqueous solution storage tank 106 Reactor 107 Cleaning tank 108 Centrifuge 109 Dryer 111 Stirring blade 112 Supply volume control device 113 Supply volume control device 115 Supply volume control device

Claims

1. A step A of treating the copper salt aqueous solution with an alkali to obtain a basic copper carbonate slurry; A step B of obtaining a copper oxide slurry from the obtained basic copper carbonate slurry; A method for producing copper oxide comprising the steps of: A method for producing copper oxide, wherein a ratio of the number of moles of the alkali metal hydroxide used in the step A to the number of moles of the alkali metal carbonate used in the step A exceeds 1.

20.

2. The method for producing copper oxide according to claim 1, The method for producing copper oxide, wherein the aqueous copper salt solution contains copper chloride.

3. The method for producing copper oxide according to claim 1 or 2, The method for producing copper oxide, wherein the alkali metal carbonate comprises sodium carbonate.

4. The method for producing copper oxide according to claim 1 or 2, The method for producing copper oxide, wherein the alkali metal hydroxide comprises sodium hydroxide.

5. 3. The method for producing copper oxide according to claim 1 or 2, The method for producing copper oxide, wherein the pH in the reaction tank in the step A is 6.0 or more and 10.0 or less.

6. 3. The method for producing copper oxide according to claim 1 or 2, The method for producing copper oxide, wherein the temperature in the reaction tank in the step A is 25° C. or higher and 95° C. or lower.

7. 3. The method for producing copper oxide according to claim 1 or 2, In the step A, the copper salt aqueous solution and the alkaline aqueous solution are simultaneously supplied into a reaction vessel.

8. The method for producing copper oxide according to claim 7, In the step A, the pH in the reaction tank is adjusted to 6.0 or more and 10.0 or less by adjusting the amount of the aqueous alkaline solution supplied per hour.

9. 3. The method for producing copper oxide according to claim 1 or 2, The method for producing copper oxide, wherein the pH in the reaction tank in the step B is 9.0 or higher.

10. 3. The method for producing copper oxide according to claim 1 or 2, The method for producing copper oxide, wherein the temperature in the reaction tank in the step B is 45° C. or higher and 95° C. or lower.

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