CN114959262B - Method for extracting metallic copper and zinc from copper-zinc mixed ore in combined way - Google Patents

Abstract

The invention provides a method for jointly extracting metallic copper and zinc from copper-zinc mixed ore. The method comprises the steps of carrying out sulfuric acid leaching on copper-zinc mixed ore to obtain high copper extraction stock solution and leaching underflow, carrying out extraction electrodeposition on the high copper extraction stock solution to obtain cathode copper, carrying out CCD countercurrent washing on the leaching underflow to obtain low copper extraction stock solution and washing underflow, carrying out extraction electrodeposition on the low copper extraction stock solution to obtain cathode copper, carrying out iron and aluminum removal and zinc powder replacement on the raffinate to obtain zinc extraction stock solution, and carrying out extraction electrodeposition on the zinc extraction stock solution to obtain cathode zinc. According to the method, copper-zinc combined extraction is carried out on the copper-zinc mixed ore, and the high copper extraction line and the low copper extraction line are respectively arranged through leaching, high copper extraction, low copper extraction and zinc extraction treatment, so that copper-rich liquid and zinc-rich liquid are obtained, and then metal copper and metal zinc are obtained in an electro-deposition mode respectively, so that the recovery rate is high, the quality is good, the production cost is low, and the economic benefit is good.

Description

Method for jointly extracting metallic copper and zinc from copper-zinc mixed ore

Technical Field

The invention relates to the technical field of nonferrous metals, and in particular to a method for jointly extracting metallic copper and zinc from a copper-zinc mixed ore.

Background Art

Copper and zinc are two common nonferrous metals, which are widely used in industrial and civilian fields. The process of extracting copper and zinc from single copper and zinc minerals is relatively mature, but with the continuous development and utilization, high-grade single copper or zinc mines are becoming less and less. How to economically develop copper-zinc mixed ores and extract metallic copper and zinc at the same time has become a hot topic of concern.

Patent CN 102851693 A discloses a process for recovering electrolytic copper and electrolytic zinc from smelting ash. The process steps of the invention include leaching - copper extraction electrowinning - neutralization and iron removal - cadmium removal - zinc extraction - zinc electrowinning. The invention uses two loops to complete the exchange reaction of zinc oxide, copper oxide and acid in the raw materials, making full use of the strong alkalinity of high-zinc smoke, avoiding the problem of large acid and alkali consumption and large zinc loss caused by calcium oxide neutralization.

However, for raw materials with weak alkalinity such as copper-zinc mixed ore, which cannot neutralize the copper extraction raffinate to more than 5, it is inevitable to add an oxidant to the copper extraction raffinate to neutralize and remove impurities. At this time, the acid in the copper extraction raffinate cannot be effectively utilized. In order to recycle the zinc in the leachate, a large amount of neutralizing agents are also needed to neutralize the residual acid in the copper extraction raffinate, and the acid-base consumption is large. Meanwhile, due to the limited copper extraction efficiency, about 5% of the copper in the leachate is lost in the neutralization and iron removal and cadmium removal procedures, and the copper recovery rate is low. This method is not suitable for the extraction of copper and zinc in the copper-zinc mixed ore, and the extraction cost is higher, and the recovery rate of copper and zinc is also lower.

Summary of the invention

The main purpose of the present invention is to provide a method for jointly extracting metallic copper and zinc from a copper-zinc mixed ore, so as to solve the problems of high cost and low recovery rate when extracting copper and zinc from a copper-zinc mixed ore in the prior art.

In order to achieve the above-mentioned object, according to one aspect of the present invention, a method for jointly extracting metallic copper and zinc from a copper-zinc mixed ore is provided, comprising the following steps: step S1, subjecting the copper-zinc mixed ore to sulfuric acid leaching to obtain a high-copper extraction stock solution and a leaching underflow; step S2, subjecting the high-copper extraction stock solution to a first copper extraction, a first washing and a first stripping in sequence to obtain a high-copper raffinate and a first copper-rich solution, returning the high-copper raffinate to the leaching process, and subjecting the first copper-rich solution to copper electrowinning to obtain cathode copper; step S3, subjecting the leaching underflow to CC extraction; D is countercurrent washing to obtain a low-copper extraction stock solution and a washing underflow, and the low-copper extraction stock solution is subjected to a second copper extraction, a second washing and a second stripping in sequence to obtain a low-copper raffinate and a second copper-rich solution, and the second copper-rich solution is subjected to copper electrowinning to obtain cathode copper; step S4, iron and aluminum removal is performed on the low-copper raffinate to obtain a solution after iron and aluminum removal, and the solution after iron and aluminum removal is subjected to zinc powder replacement to obtain a zinc extraction stock solution; zinc extraction, a third washing and a third stripping are performed on the zinc extraction stock solution in sequence to obtain a zinc raffinate and a zinc-rich solution, and the zinc-rich solution is subjected to zinc electrowinning to obtain cathode zinc.

Furthermore, the pH of the leaching process is 1.5-2.5, the leaching time is 2-4 hours, and the leaching liquid-solid ratio is 3-6.

Further, in step S2, the extractant for the first copper extraction is one or more of Lix984N, OPT5510 and M5640; preferably, the number of stages of the first copper extraction is 1 to 3, the number of stages of the first washing is 1 to 3, and the number of stages of the first stripping is 1 to 3.

Furthermore, in step S3, the wash water ratio of the CCD countercurrent washing is 1.5-4.

Furthermore, in step S3, after obtaining the washing underflow, the step further includes adding alkali to neutralize the washing underflow until the pH of the washing underflow is 8 to 10; preferably, the alkali is limestone and/or lime milk.

Further, in step S3, the extractant for the second copper extraction is one or more of Lix984N, OPT5510 and M5640; preferably, the number of stages of the second copper extraction is 1 to 3, the number of stages of the second washing is 1 to 3, and the number of stages of the second stripping is 1 to 3.

Furthermore, in step S4, the iron-aluminum removal reagent in the iron-aluminum removal process is limestone and/or lime milk; preferably, the end point of the iron-aluminum removal process is that the pH of the liquid after iron-aluminum removal is 5-6.

Furthermore, in step S4, the extractant for zinc extraction is one or more of P204, P507 and C272; preferably, the extraction level of the zinc extraction process is 3 to 5 levels, the level of the third washing is 3 to 5 levels, and the level of the third stripping is 1 to 3 levels.

Furthermore, step S4 also includes the step of deoiling and neutralizing the zinc raffinate in sequence to obtain a neutralized liquid, and returning the neutralized liquid to the CCD for countercurrent washing; preferably, limestone is used for the neutralization process, and the end point is that the pH of the neutralized liquid is 1.5 to 2.5.

Furthermore, in the copper-zinc mixed ore, the weight ratio of copper to zinc is (0.5-20):1; preferably, in the copper-zinc mixed ore, the weight ratio of copper to zinc is (2-20):1.

The technical scheme of the present invention is applied to carry out copper-zinc joint extraction on the copper-zinc mixed ore, and through leaching-high copper extraction-low copper extraction-zinc extraction treatment, a high copper extraction line and a low copper extraction line are respectively set to obtain a copper-rich solution and a zinc-rich solution, and then metallic copper and metallic zinc are obtained respectively by electrowinning. Among them, the high copper extraction line only extracts copper and does not extract zinc, and most of the copper is recovered here. The high copper raffinate is returned to the leaching process, and the residual acid therein can be fully utilized. The low copper extraction line extracts both copper and zinc. The low copper extraction process can maximize the recovery of copper, reduce the loss of copper in the subsequent iron and aluminum removal and zinc powder replacement process, not only increase the recovery rate of copper and zinc, but also reduce the consumption of neutralizer and zinc powder. The present invention obtains metallic copper and metallic zinc respectively by extraction and electrowinning, with high recovery rate, good quality, low production cost and good economic benefit.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

FIG1 shows a flow chart of an extraction process according to Example 1 of the present invention.

DETAILED DESCRIPTION

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

Terminology explanation:

Liquid-to-solid ratio: the mass ratio of the leaching solution to the copper-zinc mixed ore during the leaching process.

CCD countercurrent washing: Continuous countercurrent washing is a multi-stage washing system composed of multiple thickeners, in which the washing water (thickener overflow) and the thickener underflow (slurry) move in countercurrent.

Wash water ratio: The mass ratio of wash water to solids in underflow in CCD countercurrent washing.

As described in the background of the present invention, the prior art has the problems of high cost and low recovery rate when extracting copper and zinc from copper-zinc mixed ore. In order to solve the above problems, in a typical embodiment of the present invention, a method for jointly extracting metallic copper and zinc from copper-zinc mixed ore is provided, comprising the following steps: step S1, leaching the copper-zinc mixed ore with sulfuric acid to obtain a high-copper extract stock solution and a leaching underflow; step S2, sequentially performing a first copper extraction, a first washing and a first stripping on the high-copper extract stock solution to obtain a high-copper raffinate and a first copper-rich solution, returning the high-copper raffinate to the leaching process, and subjecting the first copper-rich solution to a leaching process. copper electrowinning is performed to obtain cathode copper; step S3, performing CCD countercurrent washing on the leaching underflow to obtain a low-copper extraction stock solution and a washing underflow, sequentially performing a second copper extraction, a second washing and a second stripping on the low-copper extraction stock solution to obtain a low-copper raffinate and a second copper-rich solution, and performing copper electrowinning on the second copper-rich solution to obtain cathode copper; step S4, removing iron and aluminum from the low-copper raffinate to obtain a solution after iron and aluminum removal, performing zinc powder replacement on the solution after iron and aluminum removal to obtain a zinc extraction stock solution, sequentially performing zinc extraction, a third washing and a third stripping on the zinc extraction stock solution to obtain a zinc raffinate and a zinc-rich solution, and performing zinc electrowinning on the zinc-rich solution to obtain cathode zinc.

The copper-zinc ore mainly contains 1.5-8wt.% copper, 0.1-4wt.% zinc, 20-45wt.% oxygen, and 20-45wt.% impurities such as iron, aluminum, calcium, magnesium, silicon, and lead. The inventor unexpectedly found in actual production that for raw materials such as these copper-zinc mixed ores with relatively weak alkalinity and unable to neutralize the copper raffinate to neutrality, the copper-zinc extraction process will inevitably add limestone and the like to the copper raffinate for neutralization and impurity removal. At this time, the acid in the copper raffinate cannot be effectively utilized, and in order to recover the zinc in the leachate, a large amount of neutralizing agent is needed to neutralize the residual acid in the copper raffinate, resulting in large acid and alkali consumption and high production cost. At the same time, due to the limited efficiency of the copper extraction step, about 5% of the copper in the leachate will be lost in the neutralization, iron and aluminum removal and impurity removal process, and the copper recovery rate is low. In view of the above problems, the inventors have specially provided the following technical scheme, which is to first subject the copper-zinc mixed ore to sulfuric acid leaching to obtain a high-copper extract solution and a leaching underflow, and then respectively perform the following operations on the high-copper extract solution: sequentially perform a first copper extraction, a first washing and a first stripping on the high-copper extract solution to obtain a high-copper raffinate and a first copper-rich solution, and return the high-copper raffinate to the leaching process to make full use of the residual acid in the raffinate, thereby reducing the acid and alkali consumption in the process, and subject the first copper-rich solution to copper electrowinning to obtain cathode copper and copper electrowinning waste liquid, and most of the copper is recovered in this high-copper extraction line.

As for the leaching underflow, CCD countercurrent washing is performed to obtain low-copper extraction stock solution and washing underflow, and the low-copper extraction stock solution is subjected to the second copper extraction, the second washing and the second stripping in sequence to obtain low-copper raffinate and the second copper-rich solution, and the second copper-rich solution is subjected to copper electrowinning to obtain cathode copper and copper electrowinning waste liquid, in which the copper of the low-copper extraction line will be recovered to the maximum extent, which can reduce the loss of copper in the subsequent neutralization, iron removal, aluminum removal and zinc powder replacement process, and improve the copper recovery rate. Finally, the low-copper raffinate is subjected to iron and aluminum removal to obtain the iron and aluminum removal liquid, and the iron and aluminum impurities are removed in this process, and the iron and aluminum removal liquid is subjected to zinc powder replacement to obtain the zinc extraction stock solution, and the zinc extraction stock solution is subjected to zinc extraction, the third washing and the third stripping in sequence to obtain the zinc raffinate and the zinc-rich solution, at which time most of the metal ions in the zinc-rich solution that affect zinc electrowinning are removed in the previous process, and the zinc-rich solution is subjected to zinc electrowinning to obtain high-quality cathode zinc and zinc electrowinning waste liquid.

To improve the leaching efficiency of the acid leaching process, in a preferred embodiment, the pH of the leaching process is 1.5-2.5, the leaching time is 2-4 hours, and the leaching liquid-solid ratio is 3-6. Under this condition, the leaching rate of copper and zinc is higher.

In a preferred embodiment, in step S2, the extractant for the first copper extraction is one or more of Lix984N, OPT5510 and M5640; for a more sufficient and rapid extraction of copper, the washing liquid can use dilute sulfuric acid, and the stripping liquid can use copper electrolytic waste liquid. Preferably, the first copper extraction has 1 to 3 levels, the first washing has 1 to 3 levels, and the first stripping has 1 to 3 levels, and the copper extraction effect is better.

In order to achieve better washing effect and further improve the copper and zinc extraction rate, in a preferred embodiment, in step S3, the washing water ratio of the CCD countercurrent washing is 1.5-4.

In order to further reduce the production cost, in a preferred embodiment, in step S3, after obtaining the washing underflow, the step of adding alkali to neutralize the washing underflow until the pH of the washing underflow is 8 to 10 is also included; preferably, the alkali is limestone and/or lime milk, and the neutralized washing underflow is sent to the tailings pond for storage for further use.

The low copper extraction line has a small amount of copper extraction, a small amount of acid generated, and a small amount of neutralizer consumed in the neutralization and iron and aluminum removal process. In a preferred embodiment, in step S3, the extractant for low copper extraction is one or more of Lix984N, OPT5510 and M5640; the washing liquid can use dilute sulfuric acid, and the stripping liquid can use copper electrolytic waste liquid. Preferably, the second copper extraction level is 1 to 3 levels, the second washing level is 1 to 3 levels, and the second stripping level is 1 to 3 levels. The copper extraction effect is better, and a small amount of copper in the low copper extraction stock solution can be further extracted, further improving the copper extraction rate, and the production cost is lower.

In order to further improve the removal efficiency of iron and aluminum impurity ions in the low-copper raffinate, in a preferred embodiment, in step S4, the iron and aluminum removal reagent in the iron and aluminum removal process is limestone and/or lime milk; preferably, the end point of the iron and aluminum removal process is that the pH value of the liquid after iron and aluminum removal is 5-6.

In a preferred embodiment, in step S4, the extractant for zinc extraction is one or more of P204, P507 and C272; the washing liquid can use dilute sulfuric acid, and the stripping liquid can use zinc electrodeposition waste liquid. Preferably, the extraction level of the zinc extraction process is 3 to 5 levels, the third washing level is 3 to 5 levels, and the third stripping level is 1 to 3 levels. Under this condition, the recovery rate of zinc is higher.

To further reduce production costs, in a preferred embodiment, step S4 further includes the step of degreasing and neutralizing the zinc raffinate in sequence to obtain a neutralized liquid, and returning the neutralized liquid to the CCD for countercurrent washing to achieve the reuse of the zinc raffinate. Preferably, limestone is used for the neutralization process, and the pH of the neutralized liquid at the end point is 1.5 to 2.5.

In a preferred embodiment, the weight ratio of copper to zinc in the copper-zinc mixed ore is (0.5-20):1; preferably, the weight ratio of copper to zinc in the copper-zinc mixed ore is (2-20):1. The above-mentioned high-copper and low-zinc copper-zinc mixed ore is more suitable for the extraction of copper and zinc using the method of the present invention.

The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

Example 1

The copper-zinc mixed ore contains 8wt.% copper, 2wt.% zinc, and the remainder is other impurities such as iron, aluminum, calcium, magnesium, and silicon.

Step S1, leaching the copper-zinc mixed ore with sulfuric acid, the pH of the leaching process is 2, the leaching time is 3 hours, the leaching liquid-solid ratio is 5, and after concentration, a high-copper extract solution and a leaching underflow are obtained.

Step S2, using Lix984N to perform a first copper extraction on the high-copper extraction solution, followed by a first washing and a first stripping, the washing solution is dilute sulfuric acid, the stripping solution is copper electrowinning waste liquid, the extraction level, the washing level and the stripping level are all 2, to obtain a high-copper raffinate and a first copper-rich solution, the high-copper raffinate is returned to the leaching process to recycle the acid therein, and the first copper-rich solution is subjected to copper electrowinning to obtain cathode copper.

Step S3, performing CCD countercurrent washing on the leaching underflow, with a washing water ratio of 3, to obtain a low-copper extract solution and a washing underflow, adding lime milk to the washing underflow to neutralize it to a pH of 9, and then sending it to a tailings pond for storage; using Lix984N to perform a second copper extraction on the low-copper extract solution, followed by a second washing and a second stripping, the washing liquid is dilute sulfuric acid, the stripping liquid is copper electrowinning waste liquid, the extraction level, the washing level and the stripping level are all 2, to obtain a low-copper raffinate and a second copper-rich solution, and the second copper-rich solution is subjected to copper electrowinning to obtain cathode copper.

Step S4, using limestone to remove iron and aluminum from the low-copper raffinate, the end point pH is 5.5, and the iron-removed aluminum liquid and the iron-removed aluminum underflow are concentrated, and the iron-removed aluminum underflow is sent to the CCD washing process; the iron-removed aluminum liquid is replaced with zinc powder to obtain replaced slag and zinc extraction stock solution; P204 is used to extract zinc from the zinc extraction stock solution, and then a third washing and a third stripping are performed, the washing liquid is dilute sulfuric acid, the stripping liquid is zinc electrodeposition waste liquid, the extraction level and the washing level are both 4 levels, and the stripping level is 2 levels, to obtain zinc raffinate and zinc-rich liquid, and the zinc-rich liquid is deoiled to obtain cathode zinc through zinc electrolysis; after deoiling the zinc raffinate, limestone is added for neutralization, and the end point pH is 2.0, and the neutralized slurry is sent to the CCD washing process as washing water.

The extraction process flow chart is shown in Figure 1.

Examples 2 to 3

The difference between Examples 2 to 3 and Example 1 is that the process conditions are different, see Table 1 for details.

Comparative Example 1

The difference between Comparative Example 1 and Example 1 is that the process conditions are different, see Table 1 for details.

Comparative Example 2

The copper-zinc mixed ore contains 8wt.% copper, 2wt.% zinc, and the remainder is other impurities such as iron, aluminum, calcium, magnesium, and silicon.

The copper-zinc mixed ore was leached with sulfuric acid. The pH of the leaching process was 2, the leaching time was 3h, and the leaching liquid-solid ratio was 5. After concentration, copper extraction solution and leaching residue were obtained. The leaching residue was pulped and neutralized and sent to the tailings pond. Lix984N was used to extract copper from the copper extraction solution, followed by washing and stripping. The washing liquid was dilute sulfuric acid, and the stripping liquid was copper electrolytic waste liquid. The extraction level, washing level and stripping level were all 2 levels to obtain copper raffinate and copper-rich solution. The copper-rich solution was subjected to copper electrolytic production to obtain cathode copper.

The copper raffinate is de-ironed and de-aluminized by limestone, with an end point pH of 5.5. The de-ironed and de-aluminized liquid and de-ironed and de-aluminized slag are concentrated and sent to the tailings pond after pulping and neutralization. The de-ironed and de-aluminized liquid is replaced with zinc powder to obtain replaced slag and zinc extraction stock solution. P204 is used to extract zinc from the zinc extraction stock solution, followed by washing and stripping. The washing liquid is dilute sulfuric acid, and the stripping liquid is zinc electrodeposition waste liquid. The extraction and washing stages are both 4, and the stripping stage is 2, to obtain zinc raffinate and zinc-rich liquid. The zinc-rich liquid is deoiled and zinc is electrolytically produced to obtain cathode zinc. The zinc raffinate is deoiled and returned to the leaching process as a leaching agent.

The leaching rates and recovery rates of copper and zinc in Examples 1 to 3 and Comparative Examples 1 to 2 are shown in Table 2.

Table 1

Example 1 Example 2 Example 3 Comparative Example 1 Leaching pH 2 1.5 2.5 3 Leaching time 3 2 4 1 Liquid-to-solid ratio 5 3 6 2.5 First copper extraction stage 2 1 3 2 First washing stage 2 1 3 1 First stripping stage 2 1 3 1 Washing water ratio 3 1.5 4 2 Second copper extraction stage 2 1 3 2 Second washing stage 2 1 3 1 Second stripping stage 2 1 3 1 Zinc extraction level 4 3 5 2 The third washing stage 4 3 5 2 The third stripping stage 2 1 3 1

Table 2

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Copper leaching rate 86.10% 85.20% 84.60% 80.30% 85.86% Zinc leaching rate 91.20% 90.50% 89.70% 81.50% 90.97% Copper recovery rate 84.60% 83.70% 83.40% 78.50% 70.12% Zinc recovery rate 75.60% 72.10% 74.30% 59.80% 74.06%

As can be seen from the above, compared with the comparative example, the embodiment of the present invention is treated by leaching-high copper extraction-low copper extraction-zinc extraction, and a high copper extraction line and a low copper extraction line are respectively set to obtain a copper-rich solution and a zinc-rich solution, and then metallic copper and metallic zinc are obtained respectively by electrolysis. Among them, the high copper extraction line only extracts copper and does not extract zinc. Most of the copper is recovered here, and the high copper raffinate is returned to the leaching process to make full use of the residual acid therein. The low copper extraction line extracts both copper and zinc. The low copper extraction process can maximize the recovery of copper and reduce the loss of copper in the subsequent iron and aluminum removal and zinc powder replacement process, which not only increases the recovery rate of copper and zinc, but also reduces the consumption of neutralizers and zinc powder. The present invention obtains metallic copper and metallic zinc respectively by extraction and electrolysis, and the leaching rate and recovery rate of metallic copper and zinc are high, the quality is good, and the production cost is low.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (12)

1. A method for jointly extracting metallic copper and zinc from a copper-zinc mixed ore, characterized in that it comprises the following steps: Step S1, leaching the copper-zinc mixed ore with sulfuric acid to obtain a high-copper extract solution and a leaching underflow; Step S2, sequentially performing a first copper extraction, a first washing and a first stripping on the high-copper extraction stock solution to obtain a high-copper raffinate and a first copper-rich solution, returning the high-copper raffinate to the leaching process, and performing copper electrowinning on the first copper-rich solution to obtain cathode copper; Step S3, performing CCD countercurrent washing on the leached underflow to obtain a low-copper extraction stock solution and a washing underflow, sequentially performing a second copper extraction, a second washing and a second stripping on the low-copper extraction stock solution to obtain a low-copper raffinate and a second copper-rich solution, and performing the copper electrowinning on the second copper-rich solution to obtain the cathode copper; Step S4, removing iron and aluminum from the low-copper raffinate to obtain a de-ironized and de-aluminized liquid, and replacing the de-ironized and de-aluminized liquid with zinc powder to obtain a zinc extraction stock solution; wherein the de-ironized and de-aluminized reagent in the de-ironized and de-aluminized process is limestone and/or lime milk, and the end point of the de-ironized and de-aluminized process is that the pH of the de-ironized and de-aluminized liquid is 5-6; The zinc extraction stock solution is subjected to zinc extraction, third washing and third stripping in sequence to obtain zinc raffinate and zinc-rich solution, and the zinc-rich solution is subjected to zinc electrolysis to obtain cathode zinc; the zinc raffinate is subjected to deoiling and neutralization in sequence to obtain a neutralized solution, and the solution is returned to the CCD for countercurrent washing; wherein the extractant for zinc extraction is one or more of P204, P507 and C272; the end point of the neutralization process is that the pH of the neutralized solution is 1.5-2.5; Among them, in the copper-zinc mixed ore, copper contains 1.5~8wt.%, zinc contains 0.1~4wt.%, and the weight ratio of copper to zinc is (0.5~20):1. 2. The method according to claim 1, characterized in that the pH of the leaching process is 1.5-2.5, the leaching time is 2-4 hours, and the leaching liquid-to-solid ratio is 3-6. 3. The method according to claim 1 or 2, characterized in that, in the step S2, the extractant for the first copper extraction is one or more of Lix984N, OPT5510 and M5640. 4. The method according to claim 3, characterized in that, in the step S2, the first copper extraction has 1 to 3 stages, the first washing has 1 to 3 stages, and the first stripping has 1 to 3 stages. 5. The method according to claim 1 or 2, characterized in that, in step S3, the wash water ratio of the CCD countercurrent washing is 1.5-4. 6. The method according to claim 1 or 2, characterized in that, in the step S3, after obtaining the washing underflow, it also includes the step of adding alkali to neutralize the washing underflow until the pH of the washing underflow is 8-10. 7. The method according to claim 6, characterized in that the alkali is limestone and/or lime milk. 8. The method according to claim 1 or 2, characterized in that, in the step S3, the extractant for the second copper extraction is one or more of Lix984N, OPT5510 and M5640. 9. The method according to claim 8, characterized in that the second copper extraction has 1 to 3 stages, the second washing has 1 to 3 stages, and the second stripping has 1 to 3 stages. 10. The method according to claim 1 or 2, characterized in that, in the step S4, the extraction level of the zinc extraction process is 3 to 5 levels, the level of the third washing is 3 to 5 levels, and the level of the third stripping is 1 to 3 levels. 11. The method according to claim 1 or 2, characterized in that, in the step S4, limestone is used to carry out the neutralization process. 12. The method according to claim 1 or 2, characterized in that the weight ratio of copper to zinc in the copper-zinc mixed ore is (2-20):1.