CN114808031B - Method for extracting copper from copper electrolysis waste liquid - Google Patents

Abstract

The invention provides a method for extracting copper from copper electrolysis waste liquid. The method adopts a novel electrolytic copper removal technology to adjust the solution flow rate, current density and end point copper ion concentration to achieve matching production of the three, thereby achieving the purpose of removing copper from the electrolyte, and controlling the system solution circulation mode to eliminate adverse factors such as concentration polarization in the electrolysis process, so that copper is precipitated at the cathode, the copper ion concentration in the electrolyte is reduced, and the copper recovery rate is further improved.

Description

A method for extracting copper from copper electrolysis waste liquid

Technical Field

The invention belongs to the technical field of metal extraction and relates to a method for extracting copper from copper electrolysis waste liquid.

Background Art

In order to ensure the stability of the solution composition of the electrolysis system, a certain amount of solution needs to be extracted for purification and impurity removal. Cyclone electrolysis technology is one of the methods for purification and impurity removal. This method is a technology for effectively separating and purifying metals. It is based on the difference in theoretical precipitation potentials of various metal ions, that is, the metal to be extracted has a large potential difference with other metal ions in the solution system. Metals with more positive potential are easy to precipitate preferentially at the cathode, and the influence of concentration polarization on electrolysis is eliminated by high-speed solution flow to produce metal products. However, this process has the defects of low cell operation rate and high labor intensity in the production process, and is not suitable for large-scale production. At the same time, the cell voltage is high, the electrical efficiency is low, and the energy consumption is high, resulting in high processing costs.

Summary of the invention

The purpose of the present invention is to provide a method for extracting copper from copper electrolysis waste liquid in view of the problems existing in the prior art, solve the problem of mismatch between solution flow rate, current density and end point copper ion concentration, eliminate the unfavorable factors such as concentration polarization in the electrolysis process by controlling the system circulation mode, and achieve the purpose of effectively removing copper from the electrolyte and improving the cathode copper recovery rate. To this end, the present invention adopts the following technical solutions:

A method for extracting copper from copper electrolysis waste liquid comprises the following steps:

a. After the copper electrolytic waste liquid is concentrated by the vacuum evaporator group, it is pumped into the pre-electrolysis liquid tank to form the pre-electrolysis liquid, wherein the copper ion concentration in the pre-electrolysis liquid is 50 to 65 g/L, the acid concentration is 200 to 250 g/L, and the temperature is 40 to 60 ° C;

b. decoppering the pre-electrolysis solution, wherein the decoppering treatment includes a first electrolysis stage and a second electrolysis stage performed in sequence, wherein the first electrolysis stage includes setting a first electrolysis circulation tank and a first electrolysis tank, adding a lead anode plate and a starting electrode sheet into the first electrolysis tank, introducing a certain amount of pre-electrolysis solution into the first electrolysis circulation tank to form a first electrolysis solution, and then pumping the first electrolysis solution into the first electrolysis tank to obtain electrolytic copper, wherein the current density in the first electrolysis stage is 90-180A/ ^m2 , the copper ion concentration is 30-55g/L, and the solution flow rate is ^1.5-6m3 /h;

The second electrowinning stage includes setting up an electrowinning second-stage circulation tank and a second electrowinning tank, a connecting pipe is provided between the electrowinning first-stage circulation tank and the electrowinning second-stage circulation tank, the upper layer solution in the electrowinning first-stage circulation tank enters the electrowinning second-stage circulation tank to form a second electrowinning solution, and then the second electrowinning solution is pumped into the second electrowinning tank for electrification to obtain electrowinning copper, that is, as the electrowinning process proceeds, metallic copper is precipitated on the starting electrode to form electrowinning copper, in the second electrowinning stage, the current density is 90-180A/ ^m2 , the copper ion concentration is 10-25g/L, the solution flow rate is ^1.5-6m3 /h, and the control index electrowinning tank temperature is 40-50℃.

c. After the electrolysis process is completed, the second electrolysis stage produces electrolysis second-stage liquid, and a connecting pipeline is provided between the electrolysis second-stage circulation tank and the electrolysis liquid tank. The electrolysis second-stage liquid enters the electrolysis liquid tank to form electrolysis liquid, and the chemical composition of the electrolysis liquid includes: Cu ²⁺ 10~25g/L, H ₂ SO ₄ 280~330 g/L.

Furthermore, the chemical composition of the copper electrolysis wastewater in step a is: Cu ²⁺ 35-45 g/L, H ₂ SO ₄ 165-180 g/L.

Furthermore, in the step b, guide plates are provided inside the first-stage electrolytic circulation tank and the second-stage electrolytic circulation tank, the top of the guide plates is connected to the top of the first-stage electrolytic circulation tank, and the bottom is at a certain distance from the bottom of the tank body. The purpose of the setting is to make the solution circulate in a bottom-in and top-out manner.

Furthermore, the electrolysis front liquid tank in step a is connected to the electrolysis first-stage circulation tank via a pipeline, and a flow control device is provided on the pipeline.

Furthermore, the specific flow direction of the pre-electrolysis liquid is as follows: the pre-electrolysis liquid enters from the left side of the guide plate of the first-stage electrolysis circulation tank, forms a first electrolysis liquid at the bottom of the first-stage electrolysis circulation tank, the first electrolysis liquid is pumped into the first electrolysis tank for electrolysis, the post-electrolysis liquid refluxes into the upper layer of the first-stage electrolysis circulation tank, and enters the second-stage electrolysis circulation tank through the connecting pipe, and flows into the bottom of the tank from the left side of the guide plate to form a second electrolysis liquid, the second electrolysis liquid is pumped into the second electrolysis tank for electrolysis, the post-electrolysis liquid refluxes into the upper layer of the second-stage electrolysis circulation tank, and enters the post-electrolysis liquid tank through the connecting pipe to form the post-electrolysis liquid.

The beneficial effects of the present invention are:

The present invention adopts the electrolytic copper removal technology, which can eliminate the adverse factors such as concentration polarization in the electrolysis process, so that copper is precipitated at the cathode, and the copper ion concentration in the electrolyte is reduced, so as to achieve the purpose of removing copper in the waste electrolyte, and the physical appearance quality of the output cathode copper product is stable, and crude copper with low main grade is output. The copper removal rate reaches more than 75%, and the process flow is short, the production operation is simple and stable, and the labor intensity is low.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the steps of the present invention;

FIG. 2 is a schematic diagram of the solution flow of the present invention.

DETAILED DESCRIPTION

The technical solution of the present invention is described below in conjunction with the accompanying drawings and implementation methods.

Embodiment 1:

As shown in FIG1 , a method for extracting copper from copper electrolysis waste liquid comprises the following steps:

a. The copper electrolysis waste liquid contains 35g/L Cu ²⁺ and 170g/L H ₂ SO ₄ . It is concentrated by a vacuum evaporator group to form a vacuum evaporated liquid, which is pumped into the pre-electrolysis liquid tank to form a pre-electrolysis liquid. The copper ion concentration of the pre-electrolysis liquid is 45g/L, the acid content is 230g/L, and the temperature is 43°C.

b. Decoppering the pre-electrolysis solution, wherein the decoppering treatment includes a first electrolysis stage and a second electrolysis stage performed in sequence, as shown in FIG2 , wherein the first electrolysis stage includes setting a first electrolysis circulation tank and a first electrolysis tank, adding a lead anode plate and a starting electrode sheet into the first electrolysis tank, continuously pumping a certain volume of the pre-electrolysis solution into the first electrolysis circulation tank to form a first electrolysis solution, and then pumping the first electrolysis solution into the first electrolysis tank to energize to obtain electrolytic copper, wherein in the first electrolysis stage: the current density is 117A/m ² , the solution flow rate is 4m ³ /h, and the copper ion concentration is 40g/L;

The second electrowinning stage includes setting an electrowinning second-stage circulation tank and a second electrowinning tank, wherein a connecting pipe is set on the upper part of the electrowinning first-stage circulation tank and the second-stage circulation tank, and part of the solution in the electrowinning first-stage circulation tank enters the second-stage circulation tank to form a second electrowinning solution, and then the second electrowinning solution is pumped into the second electrowinning tank and energized to obtain electrowinning copper, that is, as the electrowinning process proceeds, metallic copper is precipitated on the starting electrode to form electrowinning copper, wherein in the second electrowinning stage: the current density is 117A/ ^m2 , the solution flow rate is ^4m3 /h, the copper ion concentration is 21g/L, the control index electrowinning tank temperature is 45℃, and the electrowinning copper removal current efficiency is>75%;

c. After the electrolysis process is completed, the second electrolysis stage produces the second-stage electrolysis liquid. A connecting pipeline is set between the second-stage electrolysis circulation tank and the post-electrolysis liquid tank. The second-stage electrolysis liquid enters the post-electrolysis liquid tank to form the post-electrolysis liquid. The specific chemical composition of the post-electrolysis liquid is shown in Table 1, which contains Cu ²⁺ 21g/L and H ₂ SO ₄ 285g/L.

It can be seen from the experiment that under the conditions of stable control of solution flow, current density and copper ion concentration, a certain volume of waste electrolyte is treated with electrolytic decoppering, and the copper ion concentration drops from 45g/L to 21g/L, thereby reducing the copper content of the copper-containing solution, effectively removing the copper in the electrolyte, and producing an electrolytic copper product, achieving the purpose of extracting copper from the electrolyte, improving the copper recovery rate, and helping to increase profits.

Table 1 Electrolytic copper composition

Embodiment 2:

A method for extracting copper from copper electrolysis waste liquid comprises the following steps:

a. The copper electrolysis waste liquid is composed of Cu ²⁺ 40g/L and H ₂ SO ₄ 175g/L. It is concentrated by a vacuum evaporator group to form a vacuum evaporated liquid, which is pumped into the pre-electrolysis liquid tank to form a pre-electrolysis liquid. The copper ion concentration in the pre-electrolysis liquid is 52g/L, the acid content is 243g/L, and the temperature is 50°C;

b. The electrolytic pre-liquid is subjected to a copper removal treatment, wherein the copper removal treatment includes a first electrolytic stage and a second electrolytic stage performed in sequence, wherein the first electrolytic stage includes setting a first electrolytic circulation tank and a first electrolytic tank, a lead anode plate and a starting electrode plate are added to the first electrolytic tank, a certain volume of the electrolytic pre-liquid is continuously pumped into the electrolytic system for copper removal treatment, firstly, the electrolytic pre-liquid is introduced into the first electrolytic circulation tank to form a first electrolytic solution, and then the first electrolytic solution is pumped into the first electrolytic tank to be energized to obtain electrolytic copper, the current density in the first electrolytic stage is 128A/ ^m2 , the solution flow rate is ^3.5m3 /h, and the copper ion concentration is 53g/L, the second electrolytic stage includes setting a second electrolytic circulation tank and a second electrolytic tank, a connecting pipe is set on the upper part of the first electrolytic circulation tank and the second electrolytic circulation tank, part of the solution in the first electrolytic circulation tank enters the second circulation tank to form a second electrolytic solution, and then the second electrolytic solution is pumped into the second electrolytic tank to be energized to obtain electrolytic copper, the current density in the second electrolytic stage is 128A/ ^m2 , solution flow rate 3.5m ³ /h, copper ion concentration 22g / L, control indicators electrolytic cell temperature 52 ℃, electrolytic copper removal current efficiency>75%; as the electrolytic process proceeds, metallic copper is precipitated on the starting electrode to form electrolytic copper.

c. After the electrolysis process is completed, the second electrolysis stage produces the second-stage electrolysis liquid. A connecting pipeline is set between the second-stage electrolysis circulation tank and the post-electrolysis liquid tank. The second-stage electrolysis liquid enters the post-electrolysis liquid tank to form the post-electrolysis liquid. The specific chemical composition of the post-electrolysis liquid is shown in Table 2, which contains Cu ²⁺ 22g/L and H ₂ SO ₄ 280g/L.

It can be seen from the experiment that under the conditions of stable control of solution flow, current density and copper ion concentration, a certain volume of waste electrolyte is treated with electrolytic decoppering, and the copper ion concentration drops from 52g/L to 22g/L, thereby reducing the copper content of the copper-containing solution, effectively removing the copper in the electrolyte, and producing an electrolytic copper product, achieving the purpose of extracting copper from the electrolyte, improving the copper recovery rate, and helping to increase profits.

Table 2 Electrolytic copper composition

Claims (4)

1. A method for extracting copper from copper electrolysis waste liquid, characterized in that it comprises the following steps: a. After the copper electrolytic waste liquid is concentrated by the vacuum evaporator group, it is pumped into the pre-electrolysis liquid tank to form the pre-electrolysis liquid, wherein the copper ion concentration in the pre-electrolysis liquid is 50 to 65 g/L, the acid concentration is 200 to 250 g/L, and the temperature is 40 to 60 ° C; The chemical composition of the copper electrolysis wastewater in step a is: Cu ²⁺ 35-45 g/L, H ₂ SO ₄ 165-180 g/L; b. decoppering the pre-electrolysis solution, wherein the decoppering treatment includes a first electrolysis stage and a second electrolysis stage performed in sequence, wherein the first electrolysis stage includes setting a first electrolysis circulation tank and a first electrolysis tank, adding a lead anode plate and a starting electrode sheet into the first electrolysis tank, introducing a certain amount of pre-electrolysis solution into the first electrolysis circulation tank to form a first electrolysis solution, and then pumping the first electrolysis solution into the first electrolysis tank to obtain electrolytic copper, wherein the current density in the first electrolysis stage is 90-180A/ ^m2 , the copper ion concentration is 30-55g/L, and the solution flow rate is ^1.5-6m3 /h; The second electrowinning stage includes setting up an electrowinning second-stage circulation tank and a second electrowinning tank, wherein a connecting pipe is provided between the electrowinning first-stage circulation tank and the electrowinning second-stage circulation tank, and the upper layer solution in the electrowinning first-stage circulation tank enters the electrowinning second-stage circulation tank to form a second electrowinning solution, and then the second electrowinning solution is pumped into the second electrowinning tank for electrification to obtain electrowinning copper, that is, as the electrowinning process proceeds, metallic copper is precipitated on the starting electrode to form electrowinning copper, and in the second electrowinning stage, the current density is 90-180A/ ^m2 , the copper ion concentration is 10-25g/L, the solution flow rate is ^1.5-6m3 /h, and the control index electrowinning tank temperature is 40-50°C; c. After the electrolysis process is completed, the second electrolysis stage produces electrolysis second-stage liquid, and a connecting pipeline is provided between the electrolysis second-stage circulation tank and the electrolysis liquid tank. The electrolysis second-stage liquid enters the electrolysis liquid tank to form electrolysis liquid, and the chemical composition of the electrolysis liquid includes: Cu ²⁺ 10~25g/L, H ₂ SO ₄ 280~330 g/L. 2. A method for extracting copper from copper electrolysis waste liquid according to claim 1, characterized in that in the step b, guide plates are provided inside the first-stage electrolytic circulation tank and the second-stage electrolytic circulation tank, the top of the guide plate is connected to the top of the first-stage electrolytic circulation tank, and the bottom is at a certain distance from the bottom of the tank body, and the purpose of the setting is to make the solution circulate in a bottom-in and top-out manner. 3. A method for extracting copper from copper electrolysis waste liquid according to claim 1, characterized in that the pre-electrolysis liquid tank in step a is connected to the electrolysis first-stage circulation tank through a pipeline, and a flow control device is provided on the pipeline. 4. A method for extracting copper from copper electrolysis waste liquid according to claim 1, characterized in that the specific flow direction of the pre-electrolysis liquid is: the pre-electrolysis liquid enters from the left side of the guide plate of the first-stage electrolysis circulation tank, and forms a first electrolysis liquid at the bottom of the first-stage electrolysis circulation tank. The first electrolysis liquid is pumped into the first electrolysis tank for electrolysis. The post-electrolysis liquid flows back into the upper layer of the first-stage electrolysis circulation tank, and enters the second-stage electrolysis circulation tank through a connecting pipe, and flows into the bottom of the tank from the left side of the guide plate to form a second electrolysis liquid. The second electrolysis liquid is pumped into the second electrolysis tank for electrolysis. The post-electrolysis liquid flows back into the upper layer of the second-stage electrolysis circulation tank, and enters the post-electrolysis liquid tank through a connecting pipe to form a post-electrolysis liquid.