Assistant composition and method for preparing high-purity copper through electrolysis

Abstract

The invention relates to an additive composition and method for preparing high-purity copper through electrolysis, in particular to the field of high-purity copper preparation, and the additive composition comprises 0.1-10 mg / L of bromine salt, 5-50 mg / L of polyethylene glycol and 2-50 mg / L of polyvinyl alcohol on the basis of copper electrolyte. According to the additive composition provided by the invention, the deposition effect of copper in electrolytic preparation of copper is promoted by utilizing the synergistic effect of the three components, the purity of the copper product can be effectively improved, and the purity of the copper product obtained by electrolysis is greater than or equal to 99.9999%.

Description

Technical Field

[0001] This invention relates to the field of high-purity copper preparation, and more specifically to an additive composition and method for the electrolytic preparation of high-purity copper. Background Technology

[0002] High-purity copper refers to metallic copper with a purity of 5N (Cu≥99.999%) or higher. As an emerging material, high-purity copper is not only used in high-tech fields such as the preparation of high-purity analytical standard samples, various connecting wires in the electronics industry, bonding wires for electronic packaging, high-quality audio lines, integrated circuits, liquid crystal displays, sputtering targets, and ion plating, but it is also an indispensable and valuable material in the atomic energy, rocket, missile, aviation, spaceflight, and metallurgical industries.

[0003] Currently, the preparation of high-purity copper requires electrolysis. For example, CN119685885A discloses a high-purity copper electrolytic refining device. The anode and cathode are respectively set on both sides of the electrolytic cell, and an electrode gap is provided between the anode and cathode. The electrolytic cell is filled with electrolyte. The anode and cathode are respectively connected to two stages of the power supply. A mesh jacket is installed in the electrolytic cell, and the mesh jacket is set between the anode and cathode. Tantalum powder is placed in the mesh jacket.

[0004] CN110387560A discloses a method for preparing 5N high-purity copper through a single electrolysis process. The method involves preparing an electrolytic mother liquor with a copper ion concentration of 30-60 g / L and a sulfuric acid concentration of 100-300 g / L using analytical grade copper sulfate, high-purity water, and sulfuric acid. 4N grade copper is used as the anode and a stainless steel plate as the cathode, with the cathode area larger than the anode area. The number of cathode plates equals the number of anode plates plus one, arranged alternately, with a cathode-cathode distance of 20-80 mm. At room temperature, the electrolyte is directly electrolyzed and refined in a PVC electrolytic cell using a top-in, bottom-out circulation system to obtain 5N grade high-purity copper. After cleaning, drying, and vacuum packaging, high-purity copper with a copper purity greater than 5N is obtained.

[0005] However, the current electrolytic preparation of high-purity copper still suffers from poor electrolysis, resulting in low purity of the obtained high-purity copper products. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide an additive composition and method for electrolytic preparation of high-purity copper, so as to solve the defect of low product purity in the current electrolytic preparation of high-purity copper.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an additive composition for the electrolytic preparation of high-purity copper, the additive composition comprising, based on a copper electrolyte:

[0009] Bromine salt 0.1-10 mg / L, polyethylene glycol 5-50 mg / L, polyvinyl alcohol 2-50 mg / L.

[0010] The additive composition provided by this invention utilizes the synergistic effect of the three components to promote the deposition of copper in the electrolytic preparation of copper, which can effectively improve the purity of the copper product, and the purity of the electrolytic copper product is ≥99.9999%.

[0011] As a preferred embodiment of the present invention, the bromide salt includes one or a combination of at least two of sodium bromide, potassium bromide, calcium bromide, or magnesium bromide.

[0012] In a second aspect, the present invention provides a method for preparing high-purity copper by electrolysis, the method comprising: electrolyzing a copper electrolyte containing an additive composition as described in the first aspect to obtain high-purity copper.

[0013] As a preferred embodiment of the present invention, the concentration of copper in the copper electrolyte is 50-70 g / L.

[0014] As a preferred embodiment of the present invention, the pH value of the copper electrolyte is 1.5-2.

[0015] As a preferred technical solution of the present invention, the auxiliary composition is added every 40-50 hours during the electrolysis, and the amount added, based on the copper electrolyte, includes: 0.1-1 mg / L of bromide, 0.1-10 mg / L of polyethylene glycol, and 0.1-10 mg / L of polyvinyl alcohol.

[0016] Preferably, the current density of the electrolysis is 150-200 A / m. 2 .

[0017] As a preferred embodiment of the present invention, the preparation process of the copper electrolyte is as follows:

[0018] Nitric acid and crude copper are reacted to produce copper nitrate solution, and then an oxidizing agent is added for oxidation to obtain the oxidized solution;

[0019] The resulting oxidized solution was subjected to pH adjustment and settling in sequence, followed by solid-liquid separation to obtain the mother liquor;

[0020] The obtained mother liquor was concentrated, cooled, and separated into solid and liquid components to obtain copper nitrate crystals. The obtained copper nitrate crystals were used as raw materials to prepare copper electrolyte.

[0021] As a preferred embodiment of the present invention, the mass concentration of the nitric acid is 30-40%.

[0022] Preferably, the mass ratio of nitric acid to crude copper is (18-25):1.

[0023] Preferably, the reaction temperature is 50-60°C.

[0024] Preferably, the oxidant includes hydrogen peroxide.

[0025] Preferably, the amount of oxidant added is 1-1.2 times the theoretical amount of nitrite in the oxidation solution.

[0026] As a preferred embodiment of the present invention, the endpoint of the pH adjustment is a pH value of 4-5 for the solution.

[0027] Preferably, the medium for pH adjustment includes copper carbonate and / or basic copper carbonate.

[0028] Preferably, the temperature for the settling period is 50-60°C.

[0029] Preferably, the settling time is 60-65 minutes.

[0030] As a preferred embodiment of the present invention, the concentration includes a first concentration and a second concentration performed sequentially.

[0031] Preferably, the temperature of the first concentration is 80-85°C.

[0032] Preferably, the endpoint of the first concentration is when the specific gravity of the material is 1.2-1.3 g / mL.

[0033] Preferably, the temperature of the second concentration is 45-50°C.

[0034] Preferably, the endpoint of the second concentration is that the specific gravity of the material is 1.6-1.65 g / mL.

[0035] Preferably, the final temperature of the cooling process is 10-25°C.

[0036] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0037] The additive composition provided by this invention achieves the electrolytic preparation of high-purity copper by leveraging the synergistic effect of bromide salts, polyethylene glycol, and polyvinyl alcohol. At the same time, the preparation of the copper electrolyte is coordinated with a specific copper nitrate preparation process, thereby achieving the preparation of high-purity copper. The purity of the obtained copper product is ≥99.9999%.

[0038] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0039] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0040] I. This embodiment provides an additive composition for the electrolytic preparation of high-purity copper, the additive composition comprising, based on copper electrolyte:

[0041] Bromine salt 0.1-10 mg / L, polyethylene glycol 5-50 mg / L, polyvinyl alcohol 2-50 mg / L.

[0042] In this invention, by way of example, the additive composition is based on copper electrolyte, such as 1L of copper electrolyte, and includes: 0.1-10mg of bromide, 5-50mg of polyethylene glycol, and 2-50mg of polyvinyl alcohol.

[0043] In this invention, the concentration of the bromide salt in the auxiliary composition is 0.1-10 mg / L based on the copper electrolyte. For example, it can be 0.1 mg / L, 1.09 mg / L, 2.08 mg / L, 3.07 mg / L, 4.06 mg / L, 5.05 mg / L, 6.04 mg / L, 7.03 mg / L, 8.02 mg / L, 9.01 mg / L, or 10 mg / L, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0044] In this invention, the concentration of polyethylene glycol in the additive composition is 5-50 mg / L based on copper electrolyte. For example, it can be 5 mg / L, 9.5 mg / L, 14 mg / L, 18.5 mg / L, 23 mg / L, 27.5 mg / L, 32 mg / L, 36.5 mg / L, 41 mg / L, 45.5 mg / L, or 50 mg / L, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0045] In this invention, the concentration of polyvinyl alcohol in the additive composition is 2-50 mg / L based on copper electrolyte. For example, it can be 2 mg / L, 6.8 mg / L, 11.6 mg / L, 16.4 mg / L, 21.2 mg / L, 26 mg / L, 30.8 mg / L, 35.6 mg / L, 40.4 mg / L, 45.2 mg / L, or 50 mg / L, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0046] The bromide salt includes one or a combination of at least two of sodium bromide, potassium bromide, calcium bromide, or magnesium bromide.

[0047] In this invention, the combination of bromide salts can be selected as: a combination of sodium bromide and potassium bromide, a combination of potassium bromide and calcium bromide, a combination of calcium bromide and magnesium bromide, etc.

[0048] In this invention, the weight-average molecular weight of the polyethylene glycol used is 400-2000.

[0049] In this invention, the degree of alcoholysis of the polyvinyl alcohol used is ≥98%, and the weight-average molecular weight is 180,000-200,000.

[0050] II. This embodiment provides a method for preparing high-purity copper by electrolysis, the method comprising: electrolyzing a copper electrolyte containing an additive composition to obtain high-purity copper.

[0051] The concentration of copper in the copper electrolyte is 50-70 g / L, for example, it can be 50 g / L, 52 g / L, 54 g / L, 56 g / L, 58 g / L, 60 g / L, 62 g / L, 64 g / L, 66 g / L, 68 g / L or 70 g / L, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0052] The pH value of the copper electrolyte is 1.5-2, for example, it can be 1.5, 1.6, 1.7, 1.8, 1.9 or 2, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0053] The auxiliary composition is added every 40-50 hours during the electrolysis process. The amount added, based on the copper electrolyte, includes: 0.1-1 mg / L of bromide, 0.1-10 mg / L of polyethylene glycol, and 0.1-10 mg / L of polyvinyl alcohol.

[0054] In this invention, the additive composition is added in an amount based on the copper electrolyte, and the concentration of the bromide salt is 0.1-1 mg / L. For example, it can be 0.1 mg / L, 0.19 mg / L, 0.28 mg / L, 0.37 mg / L, 0.46 mg / L, 0.55 mg / L, 0.64 mg / L, 0.73 mg / L, 0.82 mg / L, 0.91 mg / L, or 1 mg / L, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0055] In this invention, the additive composition is added in an amount based on the copper electrolyte, and the concentration of polyethylene glycol is 0.1-10 mg / L. For example, it can be 0.1 mg / L, 1.09 mg / L, 2.08 mg / L, 3.07 mg / L, 4.06 mg / L, 5.05 mg / L, 6.04 mg / L, 7.03 mg / L, 8.02 mg / L, 9.01 mg / L, or 10 mg / L, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0056] In this invention, the additive composition is added in an amount based on the copper electrolyte, and the concentration of polyvinyl alcohol added is 0.1-10 mg / L. For example, it can be 0.1 mg / L, 1.09 mg / L, 2.08 mg / L, 3.07 mg / L, 4.06 mg / L, 5.05 mg / L, 6.04 mg / L, 7.03 mg / L, 8.02 mg / L, 9.01 mg / L, or 10 mg / L, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0057] In this invention, the additive composition is added every 40-50 hours during electrolysis. The amount added, based on the copper electrolyte, includes: 0.1-1 mg / L of bromide, 0.1-10 mg / L of polyethylene glycol, and 0.1-10 mg / L of polyvinyl alcohol. For example, based on 1 L of copper electrolyte, 0.1-1 mg of bromide, 0.1-10 mg of polyethylene glycol, and 0.1-10 mg of polyvinyl alcohol are added.

[0058] The current density of the electrolysis is 150-200 A / m. 2 For example, it could be 150A / m 2 155A / m 2 160A / m 2 165A / m 2 170A / m 2 175A / m 2 180A / m 2 185A / m 2 190A / m 2 195A / m 2 Or 200A / m 2 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within this range also meet the requirements.

[0059] The preparation process of the copper electrolyte is as follows:

[0060] Nitric acid and crude copper are reacted to produce copper nitrate solution, and then an oxidizing agent is added for oxidation to obtain the oxidized solution;

[0061] The resulting oxidized solution was subjected to pH adjustment and settling in sequence, followed by solid-liquid separation to obtain the mother liquor;

[0062] The obtained mother liquor was concentrated, cooled, and separated into solid and liquid components to obtain copper nitrate crystals. The obtained copper nitrate crystals were used as raw materials to prepare copper electrolyte.

[0063] The mass concentration of the nitric acid is 30-40%, for example, it can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0064] The mass ratio of nitric acid to crude copper is (18-25):1, for example, it can be 18:1, 18.7:1, 19.4:1, 20.1:1, 20.8:1, 21.5:1, 22.2:1, 22.9:1, 23.6:1, 24.3:1 or 25:1, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0065] The reaction temperature is 50-60℃, for example, it can be 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃ or 60℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0066] The oxidant includes hydrogen peroxide.

[0067] In this invention, the mass concentration of hydrogen peroxide used is 30-32%, for example, it can be 30%, 30.2%, 30.4%, 30.6%, 30.8%, 31%, 31.2%, 31.4%, 31.6%, 31.8%, or 32%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0068] The amount of oxidant added is 1-1.2 times the theoretical amount of nitrite in the oxidizing solution, for example, it can be 1, 1.02, 1.04, 1.06, 1.08, 1.1, 1.12, 1.14, 1.16, 1.18 or 1.2 times, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0069] The endpoint of the pH adjustment is a solution pH of 4-5, such as 4, 4.2, 4.4, 4.6, 4.8 or 5, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0070] The medium for pH adjustment includes copper carbonate and / or basic copper carbonate.

[0071] The settling temperature is 50-60℃, for example, it can be 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃ or 60℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0072] The settling time is 60-65 minutes, for example, it can be 60 minutes, 60.5 minutes, 61 minutes, 61.5 minutes, 62 minutes, 62.5 minutes, 63 minutes, 63.5 minutes, 64 minutes, 64.5 minutes or 65 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0073] The concentration includes a first concentration and a second concentration performed sequentially.

[0074] The temperature of the first concentration is 80-85℃, for example, it can be 80℃, 80.5℃, 81℃, 81.5℃, 82℃, 82.5℃, 83℃, 83.5℃, 84℃, 84.5℃ or 85℃, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0075] The endpoint of the first concentration is a specific gravity of 1.2-1.3 g / mL, such as 1.2 g / mL, 1.21 g / mL, 1.22 g / mL, 1.23 g / mL, 1.24 g / mL, 1.25 g / mL, 1.26 g / mL, 1.27 g / mL, 1.28 g / mL, 1.29 g / mL, or 1.3 g / mL, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0076] The second concentration temperature is 45-50℃, for example, it can be 45℃, 45.5℃, 46℃, 46.5℃, 47℃, 47.5℃, 48℃, 48.5℃, 49℃, 49.5℃ or 50℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0077] The endpoint of the second concentration is a specific gravity of 1.6-1.65 g / mL, such as 1.6 g / mL, 1.605 g / mL, 1.61 g / mL, 1.615 g / mL, 1.62 g / mL, 1.625 g / mL, 1.63 g / mL, 1.635 g / mL, 1.64 g / mL, 1.645 g / mL, or 1.65 g / mL, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0078] The endpoint temperature for cooling is 10-25℃, for example, it can be 10℃, 11.5℃, 13℃, 14.5℃, 16℃, 17.5℃, 19℃, 20.5℃, 22℃, 23.5℃ or 25℃, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0079] In this invention, during the preparation of the copper electrolyte, the obtained copper nitrate crystals can be replaced by commercially available products with the same parameters.

[0080] III. To illustrate the effects of the additive composition for the electrolytic preparation of high-purity copper provided by this invention during the electrolysis process, the following practical examples are used for explanation:

[0081] Example 1

[0082] This embodiment provides an additive composition for the electrolytic preparation of high-purity copper, the additive composition comprising, based on a copper electrolyte:

[0083] Bromine salt (sodium bromide) 5 mg / L, polyethylene glycol (weight average molecular weight of 1000) 25 mg / L, polyvinyl alcohol (weight average molecular weight of 190000, degree of alcoholysis of 98%) 25 mg / L.

[0084] The usage process is as follows:

[0085] Electrolysis of a copper electrolyte containing the aforementioned additive composition yields high-purity copper;

[0086] The copper concentration in the copper electrolyte is 60 g / L, and the pH value is 1.8.

[0087] The additive composition is added every 45 hours during the electrolysis process. The addition amount, based on the copper electrolyte, includes: 0.5 mg / L of bromide (sodium bromide), 5 mg / L of polyethylene glycol (weight-average molecular weight 1000), and 5 mg / L of polyvinyl alcohol (weight-average molecular weight 190,000, degree of hydrolysis 98%). The electrolysis current density is 180 A / m. 2 ;

[0088] The preparation process of the copper electrolyte is as follows:

[0089] Nitric acid and crude copper are reacted to produce copper nitrate solution, and then an oxidizing agent is added for oxidation to obtain the oxidized solution;

[0090] The resulting oxidized solution was subjected to pH adjustment and settling in sequence, followed by solid-liquid separation to obtain the mother liquor;

[0091] The obtained mother liquor was concentrated, cooled and separated into solid and liquid components to obtain copper nitrate crystals. The obtained copper nitrate crystals were used as raw materials to prepare copper electrolyte.

[0092] The nitric acid has a mass concentration of 35%; the mass ratio of the nitric acid to crude copper is 20:1; the reaction temperature is 55°C; the oxidant includes hydrogen peroxide (mass concentration of 31%); the amount of oxidant added is 1.1 times the theoretical amount of nitrite in the oxidation solution;

[0093] The endpoint of the pH adjustment is a solution pH of 4.5; the medium for pH adjustment includes copper carbonate; the settling temperature is 55°C; and the settling time is 62 minutes.

[0094] The concentration includes a first concentration and a second concentration performed sequentially; the temperature of the first concentration is 82°C; the endpoint of the first concentration is a specific gravity of 1.25 g / mL for the material; the temperature of the second concentration is 47°C; the endpoint of the second concentration is a specific gravity of 1.625 g / mL for the material; and the endpoint of the cooling is 20°C.

[0095] Example 2

[0096] This embodiment provides an additive composition for the electrolytic preparation of high-purity copper, the additive composition comprising, based on a copper electrolyte:

[0097] Calcium bromide (bromine salt) 10 mg / L, polyethylene glycol (weight average molecular weight 400) 50 mg / L, polyvinyl alcohol (weight average molecular weight 180,000, degree of alcoholysis 99%) 50 mg / L.

[0098] The usage process is as follows:

[0099] Electrolysis of a copper electrolyte containing the aforementioned additive composition yields high-purity copper;

[0100] The copper concentration in the copper electrolyte is 70 g / L, and the pH value is 1.5.

[0101] The additive composition is added every 50 hours during the electrolysis process. The addition amount, based on the copper electrolyte, includes: 1 mg / L of bromide (calcium bromide), 10 mg / L of polyethylene glycol (weight-average molecular weight 400), and 10 mg / L of polyvinyl alcohol (weight-average molecular weight 180,000, degree of hydrolysis 99%). The electrolysis current density is 150 A / m. 2 ;

[0102] The preparation process of the copper electrolyte is as follows:

[0103] Nitric acid and crude copper are reacted to produce copper nitrate solution, and then an oxidizing agent is added for oxidation to obtain the oxidized solution;

[0104] The resulting oxidized solution was subjected to pH adjustment and settling in sequence, followed by solid-liquid separation to obtain the mother liquor;

[0105] The obtained mother liquor was concentrated, cooled and separated into solid and liquid components to obtain copper nitrate crystals. The obtained copper nitrate crystals were used as raw materials to prepare copper electrolyte.

[0106] The nitric acid has a mass concentration of 40%; the mass ratio of the nitric acid to crude copper is 18:1; the reaction temperature is 60°C; the oxidant includes hydrogen peroxide (mass concentration of 30%); the amount of oxidant added is 1.2 times the theoretical amount of nitrite in the oxidation solution;

[0107] The endpoint of the pH adjustment is a solution pH of 5; the medium for pH adjustment is basic copper carbonate; the settling temperature is 60°C; and the settling time is 60 min.

[0108] The concentration includes a first concentration and a second concentration performed sequentially; the temperature of the first concentration is 80°C; the endpoint of the first concentration is a specific gravity of 1.2 g / mL for the material; the temperature of the second concentration is 45°C; the endpoint of the second concentration is a specific gravity of 1.6 g / mL for the material; and the endpoint of the cooling is 10°C.

[0109] Example 3

[0110] This embodiment provides an additive composition for the electrolytic preparation of high-purity copper, the additive composition comprising, based on a copper electrolyte:

[0111] Magnesium bromide (bromine salt) 0.1 mg / L, polyethylene glycol (weight average molecular weight 2000) 5 mg / L, polyvinyl alcohol (weight average molecular weight 200000, degree of alcoholysis 98%) 2 mg / L.

[0112] The usage process is as follows:

[0113] Electrolysis of a copper electrolyte containing the aforementioned additive composition yields high-purity copper;

[0114] The copper concentration in the copper electrolyte is 50 g / L, and the pH value is 2.

[0115] The additive composition is added every 40 hours during the electrolysis process. The addition amount, based on the copper electrolyte, includes: 0.1 mg / L of bromide (magnesium bromide), 0.1 mg / L of polyethylene glycol (weight-average molecular weight 2000), and 0.1 mg / L of polyvinyl alcohol (weight-average molecular weight 200000, degree of hydrolysis 98%). The electrolysis current density is 200 A / m³. 2 ;

[0116] The preparation process of the copper electrolyte is as follows:

[0117] Nitric acid and crude copper are reacted to produce copper nitrate solution, and then an oxidizing agent is added for oxidation to obtain the oxidized solution;

[0118] The resulting oxidized solution was subjected to pH adjustment and settling in sequence, followed by solid-liquid separation to obtain the mother liquor;

[0119] The obtained mother liquor was concentrated, cooled and separated into solid and liquid components to obtain copper nitrate crystals. The obtained copper nitrate crystals were used as raw materials to prepare copper electrolyte.

[0120] The nitric acid has a mass concentration of 30%; the mass ratio of the nitric acid to crude copper is 25:1; the reaction temperature is 50°C; the oxidant includes hydrogen peroxide (mass concentration of 32%); the amount of oxidant added is 1 times the theoretical amount of nitrite in the oxidation solution;

[0121] The endpoint of the pH adjustment is a solution pH of 4; the medium for pH adjustment is copper carbonate; the settling temperature is 50°C; and the settling time is 65 minutes.

[0122] The concentration includes a first concentration and a second concentration performed sequentially; the temperature of the first concentration is 85°C; the endpoint of the first concentration is a specific gravity of 1.3 g / mL for the material; the temperature of the second concentration is 50°C; the endpoint of the second concentration is a specific gravity of 1.65 g / mL for the material; and the endpoint of the cooling is 25°C.

[0123] Comparative Example 1

[0124] The only difference from Example 1 is that the sodium bromide in the adjuvant composition is replaced with an equal amount of sodium chloride.

[0125] Comparative Example 2

[0126] The only difference from Example 1 is that no bromine salt is added to the additive composition.

[0127] Comparative Example 3

[0128] The only difference from Example 1 is that polyethylene glycol is not added to the additive composition.

[0129] Comparative Example 4

[0130] The only difference from Example 1 is that polyvinyl alcohol is not added to the additive composition.

[0131] Comparative Example 5

[0132] The only difference from Example 1 is that the concentration of bromide added in the adjuvant composition is 15 mg / L.

[0133] Comparative Example 6

[0134] The only difference from Example 1 is that the concentration of polyethylene glycol in the additive composition is 60 mg / L.

[0135] Comparative Example 7

[0136] The only difference from Example 1 is that the concentration of polyvinyl alcohol added to the additive composition is 60 mg / L.

[0137] Example 4

[0138] The only difference from Example 1 is that the amount added is based on copper electrolyte, and the concentration of bromide is 10 mg / L.

[0139] Example 5

[0140] The only difference from Example 1 is that the amount added is based on copper electrolyte, and the concentration of polyethylene glycol is 20 mg / L.

[0141] Example 6

[0142] The only difference from Example 1 is that the amount added is based on copper electrolyte, and the concentration of polyvinyl alcohol is 20 mg / L.

[0143] Example 7

[0144] The only difference from Example 1 is that the first concentration is not performed in the preparation of the copper electrolyte.

[0145] Example 8

[0146] The only difference from Example 1 is that the endpoint of the first concentration in the preparation of the copper electrolyte is a specific gravity of 1.1 g / mL.

[0147] Example 9

[0148] The only difference from Example 1 is that the endpoint of the first concentration in the preparation of the copper electrolyte is a specific gravity of 1.4 g / mL.

[0149] Example 10

[0150] The only difference from Example 1 is that a second concentration is not performed in the preparation of the copper electrolyte.

[0151] Example 11

[0152] The only difference from Example 1 is that the endpoint of the second concentration in the preparation of the copper electrolyte is that the specific gravity of the material is 1.5 g / mL.

[0153] Example 12

[0154] The only difference from Example 1 is that the endpoint of the first concentration in the preparation of the copper electrolyte is a specific gravity of 1.7 g / mL.

[0155] The purity indicators of the copper products obtained in the above embodiments and comparative examples are detailed in Table 1 below.

[0156] Table 1

[0157]

[0158]

[0159] As shown in Table 1, the additive composition provided by the present invention utilizes the synergistic effect of the three to promote the deposition of copper in the electrolytic preparation of copper, which can effectively improve the purity of the copper product. The purity of the electrolytically obtained copper product is ≥99.9999%.

[0160] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0161] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0162] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A auxiliary composition for the electrolytic preparation of high-purity copper, characterized in that, The additive composition, based on copper electrolyte, comprises: Bromine salt 0.1-10 mg / L, polyethylene glycol 5-50 mg / L, polyvinyl alcohol 2-50 mg / L.

2. The adjuvant composition according to claim 1, characterized in that, The bromide salt includes one or a combination of at least two of sodium bromide, potassium bromide, calcium bromide, or magnesium bromide.

3. A method for electrolytically preparing high-purity copper, characterized in that, The method includes: electrolyzing a copper electrolyte containing the additive composition as described in claim 1 or 2 to obtain high-purity copper.

4. The method as described in claim 3, characterized in that, The copper concentration in the copper electrolyte is 50-70 g / L.

5. The method as described in claim 3, characterized in that, The pH value of the copper electrolyte is 1.5-2.

6. The method as described in claim 3, characterized in that, The additive composition is added every 40-50 hours during the electrolysis process. The amount added, based on the copper electrolyte, includes: 0.1-1 mg / L of bromide, 0.1-10 mg / L of polyethylene glycol, and 0.1-10 mg / L of polyvinyl alcohol. Preferably, the current density of the electrolysis is 150-200 A / m. 2 .

7. The method as described in claim 3, characterized in that, The preparation process of the copper electrolyte is as follows: Nitric acid and crude copper are reacted to produce copper nitrate solution, and then an oxidizing agent is added for oxidation to obtain the oxidized solution; The resulting oxidized solution was subjected to pH adjustment and settling in sequence, followed by solid-liquid separation to obtain the mother liquor; The obtained mother liquor was concentrated, cooled, and separated into solid and liquid components to obtain copper nitrate crystals. The obtained copper nitrate crystals were used as raw materials to prepare copper electrolyte.

8. The method as described in claim 7, characterized in that, The mass concentration of the nitric acid is 30-40%; Preferably, the mass ratio of nitric acid to crude copper is (18-25):1; Preferably, the reaction temperature is 50-60°C; Preferably, the oxidant includes: hydrogen peroxide; Preferably, the amount of oxidant added is 1-1.2 times the theoretical amount of nitrite in the oxidizing solution.

9. The method as described in claim 7, characterized in that, The endpoint of the pH adjustment is when the pH of the solution is 4-5; Preferably, the medium for pH adjustment includes: copper carbonate and / or basic copper carbonate; Preferably, the temperature for the settling period is 50-60°C; Preferably, the settling time is 60-65 minutes.

10. The method as described in claim 7, characterized in that, The concentration includes a first concentration and a second concentration performed sequentially. Preferably, the temperature of the first concentration is 80-85°C; Preferably, the endpoint of the first concentration is when the specific gravity of the material is 1.2-1.3 g / mL; Preferably, the temperature for the second concentration is 45-50°C; Preferably, the endpoint of the second concentration is that the specific gravity of the material is 1.6-1.65 g / mL; Preferably, the final temperature of the cooling process is 10-25°C.

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