Electrodeposition process for recovering copper from complex solutions

Abstract

The application discloses a copper electrowinning process in a complex solution. The process adjusts the concentration of cupric acid in the complex copper-containing solution, and then adds the solution into an electrowinning system. A constant current pump is used to pump the electrowinning solution in the circulating tank into a high tank to form a circulating flow of the electrowinning solution. The cathode and the anode are installed, and after being heated to a predetermined temperature, the current is adjusted to a set value. The mixed additive is added, and the electrowinning process is started. In the electrowinning process, the complex additive and the complex copper-containing solution are continuously added into the high tank, and part of the electrowinning solution is discharged from the circulating tank, so that the copper acid balance and the volume balance of the system are maintained, and the electrowinning copper is produced in the electrowinning period. The electrowinning process can produce the A-grade copper reaching the GB / T 467-2010 standard and the purity of 99.998% in the complex solution. The process is simple, the economic benefits are remarkable, the process is clean and environmentally friendly, the requirement for the equipment is low, and the continuous production can be easily realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of non-ferrous hydrometallurgy, and particularly relates to a copper electrowinning process for recovering copper from a complex solution. BACKGROUND

[0002] In the process of copper electrowinning and copper electrolysis, in order to obtain high-quality cathode copper, the Cu 2+ concentration in the solution is generally controlled between 35-50 g / L, and the concentration of impurity ions in the solution is strictly controlled. Because the Cu 2+ concentration is too low or the impurity concentration is too high, impurities are easily deposited on the cathode, thereby reducing the purity of the product; the Cu 2+ concentration is too high, CuSO4 is easily crystallized and deposited, and at the same time, the density of the electrowinning solution is high, which cannot be settled in time, adheres to the cathode as a crystallization core, and the cathode grows many particles, and the resistance of the solution increases, resulting in an increase in the cell voltage, so the Cu 2+ concentration and the impurity concentration in the electrowinning solution need to be controlled within a suitable range.

[0003] For a complex copper-containing solution, some enterprises directly electrowin to obtain low-quality cathode copper or black copper plate, and through batching, produce crude copper anodes by fire refining, which has a high recovery cost; some enterprises use a copper extraction agent composed of P204 and N902 to extract copper into an extraction solution, use dilute sulfuric acid for back extraction, and then use an electrowinning method to deposit copper. This method is essentially a purification and concentration operation, and it cannot be applied to solutions with a high acid concentration, has a small application range, and has a complex process, which not only has a high cost, but also causes secondary pollution of the mother liquor after treatment. SUMMARY

[0004] The present application discloses a copper electrowinning process for recovering copper from a complex solution, to solve any of the above and other potential problems in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution of the present application is: a copper electrowinning process for recovering copper from a complex solution, which comprises the following steps performed in sequence:

[0006] S1) A proper amount of complex copper-containing solution is added to the electrowinning system after adjusting the copper acid concentration, and the circulation is started, and the electrowinning solution in the circulation tank is pumped into the high tank by a constant flow pump to form a circulating flow of the electrowinning solution;

[0007] S2) The anode and cathode are installed in the electrowinning tank and the wires are connected, and after the temperature is stabilized, the direct current source is turned on and the current is adjusted to the set value;

[0008] S3) During the electrowinning process, the complex additive and the complex copper-containing solution are continuously supplemented into the high tank, and part of the electrowinning solution is discharged from the circulation tank, so as to maintain the copper acid balance and the volume balance of the system, and to produce electrowinning copper within the electrowinning period.

[0009] Furthermore, in the complex copper-containing solution in S1), the concentration of copper ions is 40-80 g / L, the concentration of sulfuric acid is 5-80 g / L, the concentration of iron ions is <3 g / L, the concentration of As ions is <15 g / L, the concentration of Zn ions is <20 g / L, and the concentration of Na ions is <50 g / L.

[0010] Furthermore, in S1), the concentration of copper ions in the electrolyte is controlled at 20-60 g / L, the concentration of sulfuric acid is controlled at 70-220 g / L, the concentration of chloride ions is 30-80 mg / L, the circulation rate is controlled at 50-100 ml / min, and the circulation mode is one of bottom inlet and top outlet, top inlet and bottom outlet, or parallel flow.

[0011] Furthermore, in S2), the copper electrodeposition anode is one or more of lead-silver alloy, lead-calcium, lead-tin-calcium alloy, or titanium-based lead dioxide; the cathode is 316L stainless steel or a starting electrode sheet; the electrode spacing is 6–15 cm; the electrodeposition solution temperature is controlled between 40–70 °C; and the current density is controlled between 160–340 A / m. 2 between.

[0012] Furthermore, the amount of composite additive in S3) is 10-500 g / t-Cu, more preferably 30-300 g / t-Cu; the electrowinning cycle is 2-6 days, more preferably 3-5 days.

[0013] Further, the composite additive in S3) is a combination of at least three of the following: bone glue, gelatin, guar gum, tianqing gum, carrageenan, polyacrylic acid, casein, thiourea, propylene thiourea, polyethylene glycol, chloride ions, cobalt sulfate, avermectin, sodium lignosulfonate, and calcium lignosulfonate, wherein the molecular weight of thiourea and its derivatives (thiourea, propylene thiourea, phenyl thiourea, thiourea dioxide, 2,5-dithiobisurea, aminothiourea) and polyethylene glycol is 100 to 20,000.

[0014] The beneficial effects of this invention are as follows: Due to the adoption of the above technical solution, the electrowinning process of this invention is simple, economically efficient, clean and environmentally friendly, has low equipment requirements, and is easy to achieve continuous production; at the same time, the electrowinning process of this invention, combined with the composite additive system, makes the cathode copper crystallized and effectively inhibits the precipitation of impurities at the cathode, thereby producing Grade A copper that meets the GB / T 467-2010 standard in complex copper-containing solutions, with a purity of 99.998%, and an energy consumption of nearly 1800 Kw·h / t-Cu, with an energy efficiency of over 93%. Attached Figure Description

[0015] Figure 1 This is a flowchart of an electrowinning process for recovering copper from complex solutions according to the present invention.

[0016] Figure 2 A schematic diagram of an apparatus for implementing an electrowinning process for recovering copper from a complex solution according to the present invention.

[0017] In the picture:

[0018] 1-Inlet box, 2-Electrolysis tank, 3-Overflow hole, 4-Pipe, 5-Circulation tank, 6-Constant flow pump, 7-Heat exchanger, 8-Rectifier, 9-High-level tank. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of the present invention is not limited to these embodiments.

[0020] like Figure 1 and Figure 2 As shown, the present invention discloses an electrowinning process for recovering copper from complex solutions, the process comprising the following steps performed sequentially:

[0021] S1) Adjust the concentration of copper acid in the complex copper-containing solution, add it to the electrowinning system, and start the circulation. The electrowinning solution in the circulation tank is pumped into the high-level tank by a constant flow pump to form a circulation flow of the electrowinning solution.

[0022] S2) Connect the anode and cathode in the electrodeposition cell of the electrodeposition system, start heating and wait for the temperature to stabilize, then turn on the DC power supply and adjust the current to the set value.

[0023] S3) The electrowinning process begins. During the electrowinning process, compound additives and complex copper-containing solutions are continuously introduced into the high-level tank, while some of the electrowinning solution is discharged from the circulation tank to maintain the copper-acid balance and volume balance of the system. Electrowinning copper is produced within the electrowinning cycle.

[0024] The complex copper-containing solution in S1) has a copper ion concentration of 40–80 g / L, a sulfuric acid concentration of 5–80 g / L, an iron ion concentration of <3 g / L, an As ion concentration of <15 g / L, a Zn ion concentration of <20 g / L, and a Na ion concentration of <50 g / L.

[0025] The concentration of copper ions in the electrolyte in S1) is controlled at 20-60 g / L, the concentration of sulfuric acid is controlled at 70-220 g / L, the concentration of chloride ions is controlled at 30-80 mg / L, and the circulation rate is controlled at 50-100 ml / min.

[0026] The circulation method is one of the following: bottom in, top out, top in, bottom out, or parallel flow.

[0027] In S2), the electrode distance between the cathode and anode is 6–15 cm, the electrolyte temperature is controlled between 40–70 °C, and the current density is controlled between 160–340 A / m. 2 between.

[0028] The anode is one or more of lead-silver alloy, lead-calcium, lead-tin-calcium alloy, or titanium-based lead dioxide; the cathode is 316L stainless steel or a starting electrode sheet.

[0029] The amount of composite additive in S3) is 10-500 g / t-Cu, and the electrowinning cycle is 2-6 days, more preferably 3-5 days.

[0030] The composite additive in S3) is a combination of at least three of the following: bone glue, gelatin, guar gum, tianqing gum, carrageenan, polyacrylic acid, casein, thiourea, propylene thiourea, polyethylene glycol, chloride ions, cobalt sulfate, avermectin, sodium lignosulfonate, and calcium lignosulfonate.

[0031] The electrowinning process consumes approximately 1800 kWh / t-Cu and achieves an efficiency of over 93%.

[0032] A type of Grade A copper, which is prepared using the above-mentioned electrowinning process.

[0033] Example 1

[0034] The device used is as follows Figure 2 As shown, 20L of adjusted complex copper-containing solution is first added to electrodeposition tank 2, with a copper ion concentration of 50g / L, a sulfuric acid concentration of 160g / L, and a chloride ion concentration of 50mg / L. Constant flow pump 6 is turned on, using a bottom-in, top-out circulation system, with the circulation speed controlled at 80ml / min. The complex copper-containing solution passes through pipe 4 and circulation tank 5 to the high-level tank 9, and then through inlet box 1. A Pb-Sn-Ca alloy is used as the anode, and 316L stainless steel as the cathode, with a cathode distance of 10cm. Heat exchanger 7 is turned on to control the electrolyte temperature at 45℃, and rectifier 8 is simultaneously turned on, setting the current density to 240A / m. 2 The composite additive, consisting of a mixture of guar gum, polyethylene glycol, propylene thiourea, and cobalt sulfate, was added to the circulation tank 5. The electrowinning cycle was 4 days. During the electrowinning process, the concentrations of copper acid were maintained at 50 g / L and 160 g / L, respectively, while the concentrations of iron ions were <2 g / L, As ions <15 g / L, Zn ions <20 g / L, and Na ions <40 g / L.

[0035] The power consumption is 1850 kWh / t-Cu, the power efficiency is 95%, the cathode copper is smooth and flat, and the purity is 99.998%, which meets the requirements of Grade A copper.

[0036] Example 2

[0037] A 20L adjusted complex copper-containing solution was added to the electrowinning system, with a copper ion concentration of 35g / L, a sulfuric acid concentration of 180g / L, and a chloride ion concentration of 60mg / L. A bottom-in, top-out circulation system was started, with a circulation rate controlled at 65ml / min. A titanium-based lead dioxide alloy was used as the anode, and 316L stainless steel as the cathode, with a cathode distance of 10cm. The electrolyte temperature was controlled at 45℃, and the current density was 240A / m. 2 The composite additives are guar gum, polyethylene glycol and thiourea. The electrowinning cycle is 4 days. During the electrowinning process, the concentrations of copper acid are maintained at 35 g / L and 180 g / L, respectively, the concentrations of iron ions are <3 g / L, the concentrations of As ions are <10 g / L, the concentrations of Zn ions are <15 g / L, and the concentrations of Na ions are <40 g / L.

[0038] The power consumption is 1910 kWh / t-Cu, the power efficiency is 93.6%, the cathode copper is smooth and flat, and the purity is 99.996%, which meets the requirements of Grade A copper.

[0039] Example 3

[0040] A 20L adjusted complex copper-containing solution was added to the electrowinning system, with a copper ion concentration of 25g / L, a sulfuric acid concentration of 120g / L, and a chloride ion concentration of 50mg / L. A bottom-in, top-out circulation system was started, with a circulation rate controlled at 60ml / min. A Pb-Sn-Ca alloy was used as the anode, and 316L stainless steel as the cathode, with a cathode distance of 10cm. The electrolyte temperature was controlled at 45℃, and the current density was 220A / m. 2 The composite additives are guar gum, thiourea, and cobalt sulfate. The electrowinning cycle is 4 days. During the electrowinning process, the concentrations of copper acid are maintained at 25 g / L and 120 g / L, respectively, while the concentrations of iron ions are <2 g / L, As ions are <5 g / L, Zn ions are <18 g / L, and Na ions are <45 g / L.

[0041] The power consumption is 1820 kWh / t-Cu, the power efficiency is 94.2%, the cathode copper is smooth and flat, and the purity is 99.992%, which meets the requirements of No. 1 copper.

[0042] Example 4

[0043] A 20L adjusted complex copper-containing solution was added to the electrowinning system, with a copper ion concentration of 25g / L, a sulfuric acid concentration of 120g / L, and a chloride ion concentration of 50mg / L. A bottom-in, top-out circulation system was started, with a circulation rate controlled at 60ml / min. A Pb-Sn-Ca alloy was used as the anode, and 316L stainless steel as the cathode, with a cathode distance of 10cm. The electrolyte temperature was controlled at 45℃, and the current density was 220A / m. 2The composite additives are guar gum, propylene thiourea, polyethylene glycol, and cobalt sulfate. The electrowinning cycle is 4 days. During the electrowinning process, the concentrations of copper acid are maintained at 25 g / L and 120 g / L, respectively, and the concentrations of iron ions are <2 g / L, As ions <5 g / L, Zn ions <18 g / L, and Na ions <45 g / L.

[0044] The power consumption is 1805 kWh / t-Cu, the power efficiency is 94.0%, the cathode copper is smooth and flat, and the purity is 99.997%, which meets the requirements of Grade A copper.

[0045] Table 1 shows the content of each component in the complex copper-containing solutions in Examples 1-4: unit g / L

[0046] Cu ions Sulfuric acid As ions Fe ions Zn ions Na ions Example 1 77.3 33.5 10.3 1.6 16.4 33.2 Example 2 65.2 36.1 6.8 2.4 12.3 33.2 Example 3 50 23.2 3.5 1.6 14.9 34.8 Example 4 50 23.2 3.5 1.6 14.9 34.8

[0047] The process of this invention has a wider range of applicability to copper acid, with the copper ion concentration range expanded to 25-60 g / L and the sulfuric acid concentration range expanded to 70-220 g / L. Through a suitable process and additive system, the crystals are made dense and the precipitation of impurities at the cathode is inhibited, thereby producing high-purity cathode copper products in complex solutions, which has significant economic benefits.

[0048] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0049] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An electrowinning process for recovering copper from complex solutions, characterized in that, The process includes the following steps performed in sequence: S1) Adjust the concentration of copper acid in the complex copper-containing solution, add it to the electrowinning system, and start the circulation. The electrowinning solution in the circulation tank is pumped into the high-level tank by a constant flow pump to form a circulation flow of the electrowinning solution. The concentration of copper ions in the complex copper-containing solution is 40-80 g / L, the concentration of sulfuric acid is 5-80 g / L, the concentration of iron ions is <3 g / L, the concentration of As ions is <15 g / L, the concentration of Zn ions is <20 g / L, and the concentration of Na ions is <50 g / L. The concentration of copper ions in the electrolyte is controlled at 20–60 g / L, the concentration of sulfuric acid is controlled at 70–220 g / L, the concentration of chloride ions is controlled at 30–80 mg / L, and the circulation rate is controlled at 50–100 ml / min. The circulation method is one of bottom inlet and top outlet, top inlet and bottom outlet, or parallel flow; S2) Connect both the anode and cathode in the electrodeposition cell of the electrodeposition system, start heating and wait for the temperature to stabilize, then turn on the DC power supply and adjust the current to the set value. The electrode distance between the cathode and anode is 6–15 cm, the electrolyte temperature is controlled between 40–70 °C, and the current density is controlled between 160–340 A / m. 2 between; The anode is one or more of lead-silver alloy, lead-calcium, lead-tin-calcium alloy or titanium-based lead dioxide; the cathode is 316L stainless steel or a starting plate. S3) Add a certain amount of additives and start the electrowinning process. During the electrowinning process, continuously add appropriate amounts of mixed additives and complex copper-containing solutions into the high-level tank, while simultaneously discharging part of the electrowinning solution from the circulation tank to maintain the copper acid balance and volume balance of the system. Electrowinning copper is produced within the electrowinning cycle. The electrowinning copper is Grade A copper. The dosage of the mixed additive is 10-500 g / t-Cu, and the electrowinning cycle is 2-6 days; The mixed additive is a combination of at least three of the following: bone glue, gelatin, guar gum, tianqing gum, carrageenan, polyacrylic acid, casein, thiourea, propylene thiourea, polyethylene glycol, chloride ions, cobalt sulfate, avermectin, sodium lignosulfonate, and calcium lignosulfonate. The power consumption during the electrowinning process of the aforementioned technology is close to 1800 kWh / t-Cu, and the power efficiency reaches over 93%.

2. A type of Grade A copper, characterized in that, The Grade A copper is prepared using the process described in claim 1.

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