A method for ozone-enhanced oxidative leaching of copper from copper-containing zinc calcine

Abstract

The application discloses a method for ozone-enhanced oxidation leaching of copper from copper-zinc-containing calcine, and belongs to the technical field of hydrometallurgy.Copper-zinc-containing calcine is added into an acidic leaching solution under stirring at 80-90 DEG C, and the adding is stopped when the sulfuric acid concentration of the system reaches 20-25 g / L, and leaching is carried out for 45-55 min; secondly, copper-zinc-containing calcine is added until the pH value of the system reaches 1.0-2.5, and the leaching is continued for 30-45 min by opening ozone aeration; thirdly, copper-zinc-containing calcine is added until the pH value of the system reaches 3.5-4.0, and the leaching is continued for 30-45 min by keeping ozone aeration; fourthly, copper-zinc-containing calcine is added after stopping the aeration until the pH value of the system reaches 4.5-4.8, and the leaching is continued for 30-45 min, and a Cu 2+ containing solution is obtained by solid-liquid separation. The method replaces the traditional oxidation medium with a small amount of low-cost strong oxidizing ozone, significantly reduces the raw material and operation cost of copper recovery without increasing the load of the existing leaching system, has excellent overall economy, and has good leaching effect, and can increase the leaching rate of copper in the copper-zinc-containing calcine by more than 8%.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology, specifically relating to a method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand. Background Technology

[0002] Copper recovery in zinc smelting involves recovering copper from copper-containing zinc roasted sand, rather than purchasing scrap copper. This method utilizes self-supplied raw materials, resulting in low marginal costs and high profit elasticity. Currently, the core zinc smelting business is generally operating at a low profit or even at a loss. With rising copper prices, copper recovery has become the primary profit growth point for zinc smelting companies. However, in the hydrometallurgical zinc process, the copper leaching rate in the neutral leaching process is only 55-65%. Unleached copper residue enters the fuming furnace in the acid leaching residue. Some copper volatilizes and returns to the zinc system in the flue gas, while most is lost in the water-quenched slag, failing to achieve comprehensive recovery and reducing the copper recovery rate. Therefore, improving the copper leaching rate in the roasted sand neutral leaching process, thereby enhancing the efficiency of copper recovery from the source, is a crucial prerequisite and the only way to achieve efficient and economical copper recovery in hydrometallurgical zinc smelting.

[0003] In conventional zinc hydrometallurgical processes, copper-zinc roasted sand undergoes neutral leaching, allowing most of the zinc to enter the solution while impurities such as iron, arsenic, and antimony are hydrolyzed and precipitated. However, under these conditions, the neutral leaching rate of copper is only 55%–65%, meaning a significant proportion of copper fails to enter the solution. The unleached copper remains in the acid leaching residue, which is then concentrated and processed in a fuming furnace. During the high-temperature reduction and volatilization process in the fuming furnace, some copper volatilizes into the flue gas and subsequently returns to the zinc system, forming a cycle of accumulation; the majority of the copper enters the water-quenched slag and is discharged with it, resulting in a permanent loss of copper resources. This situation leads to a comprehensive copper recovery rate far below the theoretical level, failing to achieve effective utilization of associated copper resources.

[0004] There are two main reasons for the low copper leaching rate during the neutral leaching stage. First, when the pH of the leaching system is below 2.5, the iron in the acidic leachate mainly exists as Fe. 2+ Cu exists in solution in the form of Cu 2+ Extremely easy to react with Fe 2+ A redox reaction occurs, producing Cu₂O as a precipitate, leading to a decrease in the concentration of copper ions in the solution. Copper ions act as a catalyst during the oxidation-hydrolysis precipitation of iron in zinc hydrometallurgy, and its mechanism is also based on this reaction. Secondly, as roasted sand is continuously added to the leaching system, the zinc sulfide content in the slurry gradually increases, and the redox potential (ORP) of the slurry decreases significantly. Under this reducing atmosphere, the Cu in the solution... 2+ Reacts with sulfides, Cu 2+ Reduced to Cu + It also precipitates from the solution as Cu2O, further exacerbating the loss of copper.

[0005] For the reasons mentioned above, industrial manganese powder is usually added to calcined sand during the neutral leaching process, utilizing the oxidizing properties of MnO2 to oxidize Fe. 2+ Oxidized to Fe 3+ This method also increases the redox potential of the system. However, it has the following drawbacks: the main content of MnO2 in industrial manganese powder is only 65-75%, limiting its oxidizing power. To achieve the desired effect, a large amount needs to be added, resulting in high auxiliary material costs; the oxidation reaction of MnO2 is MnO2 + 4H₂O + + 2e - → Mn 2+ The 2H2O reaction can only be carried out effectively under strongly acidic conditions (pH < 2.5). When the pH of the leaching system is > 2.5, its oxidizing power is greatly weakened or even lost. In addition, industrial manganese powder contains a variety of unconventional impurities such as Fe, SiO2, Cl, Se, Tl, and P. The introduction of these impurities not only increases the burden of subsequent purification and removal but may also interfere with the stable operation of the entire zinc smelting system.

[0006] To overcome the problems existing in the prior art, the present invention provides a method for ozone-enhanced oxidative leaching of copper in copper-zinc roasted sand. Ozone is used as a strong oxidant to replace traditional manganese powder, thereby increasing the copper leaching rate from the leaching source. This allows copper resources to enter the solution in ionic form to the maximum extent during the neutral leaching stage, laying the foundation for the recovery of metallic copper in the subsequent purification-electrowinning process. This, in turn, achieves efficient and economical recovery of copper resources in the hydrometallurgical zinc smelting process. Summary of the Invention

[0007] The purpose of this invention is to provide a method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand.

[0008] The objective of this invention is achieved as follows: the ozone-enhanced oxidative leaching method for copper in copper-zinc calcined sand includes the following steps: At 80~90℃, under stirring conditions, copper-zinc calcined sand is added to an acidic leaching solution. When the sulfuric acid concentration in the reaction system reaches 20~25g / L, the addition is stopped, and the copper-zinc calcined sand is allowed to leach under acidic conditions until the calcined sand added in this batch is completely reacted. When adding copper-zinc calcined sand for the second time, stop adding it when the pH value of the reaction system reaches 1.0~2.5, turn on ozone aeration, and continue leaching until the calcined sand added this time has completely reacted. The third addition of copper-zinc calcined sand was stopped when the pH of the reaction system reached 3.5-4.0. Ozone aeration was continued, and leaching continued until the calcined sand added in this batch was completely reacted. Stop ozone aeration, add copper-zinc calcined sand for the fourth time, and stop adding when the pH of the reaction system reaches 4.5-4.8. Continue leaching until the calcined sand added in this batch has completely reacted, and then separate the solid and liquid to obtain the target Cu-containing product. 2+ Solution.

[0009] Compared with the prior art, the technical solution described in this invention has the following advantages: 1. This technical solution, using ozone as a strong oxidant, has significant technical advantages. The oxidation-reduction potential E of ozone... 0 =+2.07 V, significantly higher than the E of MnO2 under acidic conditions. 0 =+1.23 V, thermodynamically possessing stronger oxidizing capacity; the final products of the ozone oxidation process are only O2 or H2O, without introducing any external impurities such as Mn, Fe, Cl, Se, Ti, P into the leaching system, thus avoiding interference from unconventional impurities to the zinc smelting system from the source; the ozone dosage, inlet concentration, and aeration method can all be precisely adjusted according to the slurry composition and process conditions, maintaining a stable and controllable oxidation atmosphere throughout the leaching process, and is not limited by the system pH value.

[0010] 2. This technical solution divides the entire leaching process into four controlled stages. The enhanced leaching stage relies on the chemical leaching effect of high-concentration sulfuric acid to preferentially dissolve the soluble phase in the copper-zinc calcined sand, while simultaneously causing the initial dissociation of complex mineral lattices such as zinc ferrite. Ozone is not activated during this stage to avoid excessive ozone consumption on the oxidation of non-target minerals, thus ensuring ozone utilization efficiency.

[0011] 3. The second and third stages involve ozone aeration to enhance leaching. The second stage leaching takes place in a strongly acidic environment with a pH of 1.0–2.5 and a high oxidation potential. Ozone can remove sulfur from sulfide minerals. 2- Rapid oxidation to SO4 2- This disrupts the mineral lattice, releasing copper as Cu. 2+ The selection of this pH range simultaneously takes into account both preventing copper hydrolysis and ensuring Fe... 2+ The dual requirement of being fully oxidized by ozone.

[0012] 4. In the third stage, ozone aeration is maintained to remove the Fe generated during the second stage. 3+ Removed by hydrolysis and precipitation, while also removing residual Fe. 2+ Further oxidation. The optimized pH range at this stage can balance Fe... 3+ Hydrolysis precipitation and Cu 2 + Retention in solution, avoiding large amounts of Fe 3+ It forms a colloid in the solution, adsorbing the leached Cu. 2+ Co-precipitation into the slag phase reduces copper recovery rate.

[0013] 5. This technical solution involves adding copper-zinc calcined sand for the fourth time after ozone aeration has ceased, and raising the final pH value of the reaction system to 4.5-4.8 to minimize the residual trace amounts of Fe. 3+Al 3+ By allowing impurity ions to fully hydrolyze and precipitate while ensuring that copper does not hydrolyze, the leaching and purification processes are integrated.

[0014] In summary, this technical solution uses a small amount of low-cost, highly oxidizing ozone to replace traditional manganese powder as the oxidation medium. Without increasing the load on the existing leaching system, it significantly reduces the raw material and operating costs of copper recovery, resulting in excellent overall economic efficiency and good leaching effect. It can increase the copper leaching rate in copper-zinc calcined sand by more than 8%, making it highly valuable for promotion and application. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of the technical solution described in this invention; Figure 2 This is a diagram of the micro / nano bubble generator device used in the technical solution described in this invention. Detailed Implementation

[0016] The present invention will be further described below, but this is not intended to limit the invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the scope of protection of the present invention.

[0017] The ozone-enhanced oxidative leaching method for copper-zinc-containing calcined sand according to the present invention includes the following steps: At 80~90℃, under stirring conditions, copper-zinc calcined sand is added to an acidic leaching solution. When the sulfuric acid concentration in the reaction system reaches 20~25g / L, the addition is stopped, and the copper-zinc calcined sand is allowed to leach under acidic conditions until the calcined sand added at this time is completely reacted. That is, the sulfuric acid concentration at the end of this leaching stage is controlled to be 20~25g / L.

[0018] When adding copper-zinc calcined sand for the second time, stop adding when the pH of the reaction system reaches 1.0~2.5, turn on ozone aeration, and continue leaching until the calcined sand added this time has completely reacted. That is, control the pH of the leaching endpoint at 1.0~2.5.

[0019] The third addition of copper-zinc calcined sand is stopped when the pH of the reaction system reaches 3.5-4.0. Ozone aeration is continued, and leaching continues until the calcined sand added in this stage has completely reacted. That is, the pH of the final leaching stage is controlled to be 3.5-4.0.

[0020] Then, ozone aeration was stopped, and copper-zinc calcined sand was added for the fourth time. Addition was stopped when the pH of the reaction system reached 4.5-4.8. Leaching continued until the added calcined sand had completely reacted, i.e., the pH of this leaching endpoint was controlled at 4.5-4.8. After the reaction was completed, solid-liquid separation yielded the target Cu-containing product. 2+ Solution.

[0021] The acidic leachate is any one or a mixture of zinc electrolysis waste electrolyte, dilute sulfuric acid, zinc oxide flue gas leaching liquid, acidic leachate supernatant, and zinc sulfate cobalt precipitation filtrate, containing 80~90g / l of H2SO4.

[0022] To better match experimental data with actual production, the preparation of acidic leachate was consistent with production. Under the premise of ensuring volume balance in the wet process, the acidic leachate was prepared by combining zinc oxide flue dust leachate and acidic leachate supernatant at a volume ratio of 2:7. The H2SO4 concentration of the acidic leachate was controlled by adjusting the amount of zinc electrolysis waste electrolyte added.

[0023] The preferred H2SO4 concentration in the acidic leachate is 80-90 g / L, which provides sufficient hydrogen ion activity, enhances mineral lattice dissociation, and improves the leaching rate and extraction yield of valuable metals. This sulfuric acid concentration range can inhibit excessive dissolution of impurities such as iron, aluminum, and silicon, improve the filtration and settling performance of the slurry, and reduce the solution purification load and reagent consumption. It also balances acid consumption, energy consumption, and equipment corrosion, offering high process flexibility and adaptability to fluctuations in raw material grade.

[0024] The copper-zinc calcined sand has a particle size of <75μm and accounts for ≥85%, with a Cu content >0.5%. Under these particle size conditions, efficient dissociation and acid dissolution of copper in the material are ensured, while avoiding the deterioration of liquid-solid-liquid separation after leaching due to excessively fine particles.

[0025] The copper-zinc calcined abrasive is added in batches, with the abrasive added at the rate required to maintain the pH of the reaction system, based on real-time monitoring of the pH value.

[0026] The enhanced leaching time is 45-55 minutes, which helps ensure efficient leaching of the target metallic copper while effectively inhibiting excessive dissolution of impurity elements. The total ozone aeration leaching time is 1.0-1.5 hours, ensuring sufficient oxidation time and reducing Fe content in the process. 2+ Complete oxidation and precipitation, and the two-stage linkage can enhance the mass transfer effect of mineral reaction and improve the leaching efficiency of valuable metals.

[0027] The aeration gas is ozone, which has a high oxidation-reduction potential and a much stronger oxidizing power than chlorine, hydrogen peroxide, and air oxidation. It can quickly oxidize and decompose sulfides and low-valence metal ions (Fe2+, etc.), with a fast reaction rate and high treatment efficiency.

[0028] The ozone content of the ozone aeration is 10-20%, preferably 15-20%, and the gas flow rate is 0.4-1 L / min, preferably 0.6-0.8 L / min. It offers a wide controllable range and strong process adaptability. Within this concentration range, the ozone oxidation potential is moderate, enabling efficient oxidation and decomposition of organic matter, complexes, and low-valence metal ions, while precisely controlling the oxidation depth to avoid over-oxidation leading to side reactions and secondary dissolution of impurities. The large adjustable concentration allows for adaptation to fluctuations in raw material composition, flexibly matching the reaction requirements of each stage of leaching, impurity removal, and purification. The oxidation reaction is highly controllable, and the process stability is high.

[0029] The aeration device is a micro-nano bubble generator, which produces bubbles with small particle size, large specific surface area, and long liquid phase residence time, which can significantly improve gas-liquid mass transfer efficiency and gas dissolution utilization rate, and effectively enhance mineral activation and target component leaching reaction.

[0030] The preferred reaction temperature is 85~88℃. This temperature is within the thermodynamically optimal range, which can significantly accelerate the ion diffusion and mineral interface reaction rate, thereby improving the kinetic efficiency of valuable metal leaching.

[0031] The stirring speed is 400~600 r / min, preferably 500 r / min. Matching the stirring intensity with the production stirring intensity allows the slurry to be fully suspended and turbulent, the solid-liquid interface to be renewed in a timely manner, eliminating local excessive concentration and enhancing mass transfer efficiency.

[0032] The leaching time is controlled based on the complete reaction of the copper-zinc calcined sand added each time. The enhanced leaching time after the first addition of copper-zinc calcined sand is 45-55 min; the leaching time after the second, third and fourth additions of copper-zinc calcined sand is 30-45 min.

[0033] The leaching time range of 30 to 55 minutes given in this technical solution is a preferred method limited by the capacity of the applicant's existing production equipment. In actual industrial production, when the capacity of the equipment changes, the leaching reaction time can be adjusted accordingly based on the actual reaction rate of the calcined sand.

[0034] Example 1

[0035] Preparation before the experiment: Prepare an acidic leaching solution using the acidic leaching supernatant, zinc oxide fume leaching solution, zinc electrolysis waste electrolyte, and zinc sulfate cobalt precipitation filtrate. The composition of the acidic leaching solution is: H2SO4: 85g / L, Cu 2+ 62 mg / L (carried in from the acidic leaching supernatant), Fe 2+ 2423 mg / L, Zn 2+ 79 g / L. The copper-zinc calcined sand was ground and sieved to ensure that the proportion of particles <75 μm was ≥85%. The chemical composition was analyzed and found to contain 0.83% Cu.

[0036] Install and fix the aeration head at the bottom of the reaction beaker, and set the parameters of the ozone micro-nano bubble generator to 15% ozone content and 0.6 L / min gas flow rate.

[0037] Take 5L of acidic leachate into a beaker, heat it in a water bath to 85℃, and start stirring at a speed of 500r / min. Calculate the amount of calcined ...

[0038] The second addition of copper-zinc calcined sand was also done in batches and slowly, while the pH value of the system was monitored. When the pH value of the reaction system reached 2.5, the addition was stopped, ozone aeration was turned on, and leaching continued for 35 minutes.

[0039] The copper-zinc calcined sand was added for the third time, in the same way as before. When the pH of the reaction system reached 3.5, the addition was stopped, and ozone aeration was continued for another 35 minutes.

[0040] Stop ozone aeration, add copper-zinc calcined sand for the fourth time, in the same manner as before. Stop adding when the pH of the reaction system reaches 4.5, continue leaching for 35 minutes, then stop the reaction. Filter, and separate the solid and liquid to obtain the target Cu-containing product. 2+ Solution.

[0041] Upon testing, the filtrate (i.e., the target Cu content) 2+ (Solution) containing Cu 2+ : 718mg / l, total Fe: 6mg / l, Zn 2+ 142 g / L; slag rate 39%, filter residue Cu content: 0.51%, Cu leaching rate 76.18%.

[0042] Example 2

[0043] Preparation before the experiment: Prepare an acidic leaching solution using the acidic leaching supernatant, zinc oxide fume leaching solution, zinc electrolysis waste electrolyte, and zinc sulfate cobalt precipitation filtrate. The composition of the acidic leaching solution is: H2SO4: 88 g / L, Cu 2+ 76 mg / L (carried in from the acidic leaching supernatant), Fe 2+ 3156 mg / L, Zn 2+ 69 g / L. The copper-zinc calcined sand was ground and sieved to ensure that the proportion of particles <75 μm was ≥85%. The chemical composition was analyzed and found to contain 0.62% Cu.

[0044] Install and fix the aeration head at the bottom of the reaction beaker, and set the parameters of the ozone micro-nano bubble generator to 20% ozone content and 0.8 L / min gas flow rate.

[0045] Take 5L of acidic leachate into a beaker, heat it in a water bath to 85℃, and start stirring at a speed of 500r / min. Calculate the amount of calcined ...

[0046] The second addition of copper-zinc calcined sand was also done in batches and slowly, while the pH value of the system was monitored. When the pH value of the reaction system reached 2.5, the addition was stopped, ozone aeration was turned on, and leaching continued for 35 minutes.

[0047] The copper-zinc calcined sand was added for the third time, in the same way as before. When the pH of the reaction system reached 3.5, the addition was stopped, and ozone aeration was continued for another 35 minutes.

[0048] Stop ozone aeration, add copper-zinc calcined sand for the fourth time, in the same manner as before. Stop adding when the pH of the reaction system reaches 4.5, continue leaching for 35 minutes, then stop the reaction. Filter, and separate the solid and liquid to obtain the target Cu-containing product. 2+ Solution.

[0049] Upon testing, the filtrate (i.e., the target Cu content) 2+ (Solution) containing Cu 2+ 554 mg / L, Total Fe: 8 mg / L, Zn 2+ 137 g / L; slag rate 40%, filter residue Cu content: 0.43%, Cu leaching rate 75.23%.

[0050] As can be seen from Example 2, when Fe in the leachate 2+ As the content increases, the required amount of oxidant for the entire leaching process also increases. However, by correspondingly increasing the ozone content to 20% and the gas flow rate to 0.8 L / min, the total Fe concentration after the reaction is less than 10 mg / L, which meets the requirements of the subsequent purification process. Simultaneously, the copper leaching rate is also relatively high. This invention is well-suited to actual on-site production and has high value for industrialization and promotion.

[0051] Example 3

[0052] —Comparative Example 1 The copper-zinc calcined sand and acidic leachate from Example 1 were used, and the temperature, time, and pH control during the leaching process were the same as in Example 1.

[0053] In the enhanced leaching stage, conventionally used manganese powder is added, according to the Fe content in the reaction system. 2+The calculated amount of manganese powder needed is 1.2 times the theoretical amount, and an appropriate excess of manganese powder is added to ensure Fe content. 2+ Complete oxidation was carried out, and ozone aeration was not introduced in other stages. All other conditions were the same as in Example 1.

[0054] Following the procedure in Example 1, the reaction was completed and then filtered. Upon testing, the filtrate contained Cu. 2+ 325 mg / L, Total Fe: 7 mg / L, Zn 2+ 139 g / L; slag rate 41%, Cu content in filter residue: 0.57%, Cu leaching rate 67.73%.

[0055] Compared with Example 1, the results show that the amount of MnO2 added by conventional oxidant was 1.2 times the theoretical amount, but the copper leaching rate was still lower than that of ozone aeration oxidation in Example 1, by 8.45%.

[0056] Example 4

[0057] —Comparative Example 2 The copper-zinc calcined sand and acidic leachate from Example 2 were used, and the temperature, time, and pH control during the leaching process were the same as in Example 2.

[0058] In the enhanced leaching stage, conventionally used manganese powder is added, according to the Fe content in the reaction system. 2+ The calculated amount of manganese powder needed is 1.2 times the theoretical amount, and an appropriate excess of manganese powder is added to ensure Fe content. 2+ Complete oxidation was carried out, and ozone aeration was not introduced in other stages. The remaining conditions were the same as in Example 2.

[0059] Following the procedure in Example 2, the reaction was completed and then filtered. Upon testing, the filtrate contained Cu. 2+ 216 mg / L, Total Fe: 28 mg / L, Zn 2+ 130g / l; slag rate 43%, filter residue Cu content: 0.57%, Cu leaching rate 66.15%.

[0060] Compared with Example 2, the results show that the amount of MnO2 added as the conventional oxidant was already 1.2 times the theoretical amount, but the copper leaching rate was still 9.07% lower than that achieved by ozone aeration oxidation in Example 2. The total Fe in the filtrate was 28 mg / L, which did not meet the production control standard of <10 mg / L. When the Fe in the acidic leachate... 2+ As the content increased, the oxidizing effect of added manganese powder was limited, leading to an increase in the total Fe content in the filtrate. Simultaneously, with the increase in the amount of calcined sand added in the second and third stages, the amount of zinc sulfide in the reaction system increased by the same amount, significantly reducing the oxidizing power of the reaction system and potentially causing Cu in the solution to rise. 2+ Reduced to Cu+ As copper precipitates in the form of Cu2O, the copper leaching rate decreases accordingly.

Claims

1. A method for ozone-enhanced oxidative leaching of copper from copper-zinc-containing calcined sand, characterized in that, The process includes the following steps: At 80~90℃, under stirring conditions, copper-zinc calcined sand is added to an acidic leaching solution. When the sulfuric acid concentration in the reaction system reaches 20~25g / L, the addition is stopped, and the copper-zinc calcined sand is allowed to leach under acidic conditions until the calcined sand added in this batch is completely reacted. When adding copper-zinc calcined sand for the second time, stop adding it when the pH value of the reaction system reaches 1.0~2.5, turn on ozone aeration, and continue leaching until the calcined sand added this time has completely reacted; The third addition of copper-zinc calcined sand was stopped when the pH of the reaction system reached 3.5-4.

0. Ozone aeration was continued, and leaching continued until the calcined sand added in this batch was completely reacted. Stop ozone aeration, add copper-zinc calcined sand for the fourth time, and stop adding when the pH of the reaction system reaches 4.5-4.

8. Continue leaching until the calcined sand added in this batch has completely reacted; solid-liquid separation yields the target Cu-containing product. 2+ Solution.

2. The method for ozone-enhanced oxidative leaching of copper from copper-zinc calcined sand according to claim 1, characterized in that, The acidic leachate is any one or a mixture of zinc electrolysis waste electrolyte, dilute sulfuric acid, zinc oxide flue gas leaching liquid, acidic leachate supernatant, and zinc sulfate cobalt precipitation filtrate, containing 80~90g / l of H2SO4.

3. The method for ozone-enhanced oxidative leaching of copper from copper-zinc calcined sand according to claim 2, characterized in that, The acidic leachate is composed of zinc oxide fume leaching liquid and acidic leachate supernatant in a volume ratio of 2:

7. The H2SO4 concentration of the acidic leachate is controlled by adjusting the amount of zinc electrolysis waste electrolyte added.

4. The method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand according to claim 1, characterized in that, The copper-zinc calcined sand has a particle size of <75μm accounting for ≥85%, and contains >0.5% Cu.

5. The method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand according to claim 1, characterized in that, The copper-zinc calcined abrasive is added in batches, with the abrasive added at the rate required to maintain the pH of the reaction system, based on real-time monitoring of the pH value.

6. The method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand according to claim 1, characterized in that, The ozone content of the ozone aeration is 10-20%, and the gas flow rate is 0.4-1 L / min.

7. The method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand according to claim 6, characterized in that, The ozone content of the ozone aeration is 15-20%, and the gas flow rate is 0.6-0.8 L / min.

8. The method for ozone-enhanced oxidative leaching of copper from copper-zinc calcined sand according to claim 1, characterized in that, The reaction temperature is 85~88℃.

9. The method for ozone-enhanced oxidative leaching of copper from copper-zinc calcined sand according to claim 1, characterized in that, The stirring speed is 500 r / min.

10. The method for ozone-enhanced oxidative leaching of copper in copper-zinc calcined sand according to claim 1, characterized in that, The leaching time is 30-55 minutes.

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