Copper sulfate-free copper-zinc sulfide ore flotation separation method

Abstract

The invention relates to a copper sulfate-free copper-zinc sulfide ore flotation separation method, and relates to the technical field of mineral flotation separation. The method comprises the following steps: obtaining copper-zinc sulfide ore pulp; by taking ethionine ester as a collecting agent and lime as an inhibitor, carrying out copper-zinc bulk flotation on the copper-zinc sulfide ore pulp to obtain copper-zinc bulk concentrate and discardable tailings; zinc sulfate serves as an inhibitor, the copper-zinc bulk concentrate is subjected to regrinding treatment, and copper-zinc bulk concentrate pulp is obtained; copper flotation is conducted on the copper-zinc bulk concentrate pulp, and copper concentrate and copper tailing pulp are obtained; with ethionine ester as a collecting agent, the copper tailing ore pulp is subjected to sphalerite activation under the condition of aeration stirring, and activated sphalerite ore pulp is obtained; and carrying out flotation on the activated sphalerite by using lime as an inhibitor to obtain zinc concentrate. The scheme provided by the invention has the advantages that heavy metal pollution is avoided, the mineral separation cost is reduced, and the process adaptability is high.

Description

Technical Field

[0001] The present application relates to the technical field of mineral flotation separation, and in particular to a flotation separation method for copper-zinc sulfide ore without copper sulfate. Background Art

[0002] Copper-zinc sulfide ore is an important strategic resource, and its separation process has become a core problem in the field of mineral processing due to the dense symbiosis between minerals, fine embedded particle size and similar floatability. At present, the mainstream flotation separation processes at home and abroad are divided into two categories: preferential flotation of copper-copper tailings activation flotation of zinc and copper-zinc mixed flotation-mixed concentrate separation of copper-copper tailings activation flotation of zinc. The former uses high-alkali media and zinc sulfate to inhibit zinc minerals, and after preferentially recovering copper minerals, copper sulfate is added to the copper tailings to activate sphalerite + conventional butyl xanthate to achieve zinc flotation; the latter requires copper sulfate activation of sphalerite in the copper tailings after the copper is separated from the mixed flotation concentrate, and then conventional butyl xanthate is used as a collector to flotate and recover the sphalerite. The activation mechanism of sphalerite by copper sulfate has been widely studied: Cu 2+ A copper sulfide (CuS) film is formed on the surface of sphalerite (ZnS) through ion exchange reaction, making its floatability close to that of chalcopyrite. Conventional xanthate collectors are then used to adsorb and float the sphalerite to achieve sphalerite recovery. However, in order to effectively activate sphalerite, the traditional process requires the addition of 200-600g / t of copper sulfate during the zinc flotation operation, resulting in the following significant drawbacks: Environmental risks: CuS produced by the hydrolysis of copper sulfate 2+ Discharged with wastewater, it becomes the sole source of heavy metal copper contamination in mineral processing wastewater, increasing subsequent water treatment costs and environmental pollution risks. Economic costs: Copper sulfate is expensive per unit, and companies processing millions of tons of ore annually have annual reagent costs exceeding 10 million yuan. Process limitations: High-alkaline environments require excessive copper sulfate to compensate for Cu(OH)2 precipitation losses, exacerbating reagent waste. Although recent patented technologies have made progress in optimizing copper-zinc separation accuracy and reducing collector dosage, none have overcome the reliance on copper sulfate. For example, patent CN104289317A discloses a method for the depressant-free flotation separation of difficult-to-separate, high-sulfur copper-zinc sulfide ores. By adjusting the slurry potential to alter the floatability of copper and zinc minerals, depressant-free copper-zinc flotation separation is achieved. This method has a simple process flow, is easy to control, and can save reagent costs, but the flotation zinc operation still requires the addition of copper sulfate to activate the zinc; Patent CN112844818A discloses a method for the separation of copper-zinc sulfide ores, which uses a treatment method that gets rid of the first inhibition and then activation in the zinc flotation section, but still adds a high amount of copper sulfate to expand the flotation difference between sphalerite and other minerals. These patents show that the existing technology is still limited by the traditional paradigm of "copper sulfate activation" and it is difficult to solve its inherent environmental and economic bottlenecks. In summary, the development of a flotation separation method for copper-zinc sulfide ores that does not require the addition of copper sulfate can not only avoid the risk of heavy metal pollution, but also significantly reduce the cost of mineral processing, and has urgent industrial application value. Summary of the Invention

[0003] In order to overcome the problems existing in the related art, the present application provides a flotation separation method for copper-zinc sulfide ore without copper sulfate, which has the advantages of avoiding heavy metal pollution, reducing mineral processing costs and having strong process adaptability.

[0004] The present application provides a flotation separation method for copper-zinc sulfide ore without copper sulfate, comprising the following steps:

[0005] S1. Obtaining copper-zinc sulfide ore slurry;

[0006] S2. Using ethiocarbamate as a collector and lime as a depressant, the copper-zinc sulfide ore pulp is subjected to copper-zinc mixed flotation, wherein the amount of ethiocarbamate used is 30 g / t to 60 g / t, and the amount of lime used is 500 g / t to 800 g / t, to obtain a copper-zinc mixed concentrate and discardable tailings;

[0007] S3, regrinding the copper-zinc mixed concentrate using zinc sulfate as an inhibitor to obtain a copper-zinc mixed concentrate slurry;

[0008] S4, performing copper flotation on the copper-zinc mixed concentrate slurry to obtain copper concentrate and copper tailings slurry;

[0009] S5. Using ethylthiocarbamate as a collector, the copper tailings slurry is subjected to sphalerite activation under aeration and stirring conditions, wherein the amount of ethylthiocarbamate used is 200 g / t to 350 g / t to obtain an activated sphalerite slurry;

[0010] S6. Using lime as a depressant, the activated sphalerite is floated, wherein the amount of lime used is 200 g / t to 500 g / t, to obtain zinc concentrate.

[0011] In some embodiments, in step S1, obtaining the copper-zinc sulfide ore pulp is specifically as follows:

[0012] The ore material containing copper sulfide and zinc sulfate is ground until 65% to 72% of the ore material has a particle size of less than 74 μm.

[0013] In some embodiments, the ore containing copper sulfide and zinc sulfate is a mixture of copper sulfide minerals and zinc sulfide minerals, the copper sulfide minerals include at least one of chalcopyrite, covellite, bornite and tetrahedrite, the zinc sulfide minerals include sphalerite and / or marmatite, and the iron content of the marmatite is 4% to 12%.

[0014] In some embodiments, in step S2, the copper-zinc mixed flotation is specifically as follows:

[0015] Performing one roughing selection, at least one fine selection and at least one sweeping selection in sequence;

[0016] The copper-zinc mixed concentrate contains 8% to 12% copper and 8% to 15% zinc;

[0017] The copper content of the discardable tailings is less than 0.2%, and the zinc content is less than 0.5%.

[0018] In some embodiments, in step S2, ethionamide and lime are both added before the first roughing.

[0019] In some embodiments, in step S3, the amount of zinc sulfate used is 200 g / t to 300 g / t, and the regrinding treatment of the copper-zinc mixed concentrate is specifically as follows:

[0020] The copper-zinc mixed concentrate is ground using a vertical stirred mill or an overflow ball mill until 85% to 90% of the material particles have a size of less than 26 μm.

[0021] In some embodiments, in step S4, copper flotation is specifically performed as follows:

[0022] Carry out one roughing process and at least one fine cleaning process in sequence;

[0023] The copper concentrate has a copper content greater than 18% and a zinc content less than 5%;

[0024] The copper tailings have a copper content of less than 1.5% and a zinc content of more than 10%.

[0025] In some embodiments, in step S5, the aeration volume of the aeration stirring is 0.05 to 0.20 m 3 / h, stirring speed is 650r / min~1000r / min, and stirring time is 4min~6min.

[0026] In some embodiments, in step S6, the activated sphalerite is subjected to flotation as follows:

[0027] The activated sphalerite is subjected to a roughing separation, a scavenging separation and at least one concentrating separation in sequence;

[0028] The zinc content of the zinc concentrate is greater than 45%.

[0029] In some embodiments, in step S6, lime is added during the first concentration.

[0030] The technical solution provided by this application may have the following beneficial effects:

[0031] The flotation separation method provided in this application uses the synergistic effect of replacing copper sulfate with ethylthiocarbamate, which fundamentally eliminates the pollution of heavy metal copper ions in mineral processing wastewater, is environmentally friendly, significantly reduces environmental risks, and is conducive to the realization of green development of the mining industry. At the same time, by optimizing the flotation process, the quality and recovery rate of copper-zinc concentrate are improved, and the overall economic benefits are further improved. In addition, this flotation separation method breaks through the paradigm that traditional copper-zinc sulfide ore flotation separation relies on copper sulfate activation, and innovatively uses a large dose of ethylthiocarbamate to achieve full activation of sphalerite under aeration and stirring conditions, providing a new technical path for the clean sorting of copper-zinc sulfide ores. Finally, the process flow of this flotation separation method is clear, the operation is simple, and it is easy to realize industrial application, providing strong support for the efficient and environmentally friendly sorting of copper-zinc sulfide ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0033] Figure 1 This is a process flow diagram of a specific implementation method shown in the examples of this application;

[0034] Figure 2 It is a process flow diagram of the prior art. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0036] Prior art flotation separation processes for copper-zinc sulfide ores have long relied on copper sulfate to activate sphalerite, forming an activation mechanism centered around an ion exchange reaction. This activation method requires a highly alkaline environment, leading to the risk of heavy metal copper contamination in the beneficiation wastewater. Furthermore, the high cost of copper sulfate and the resulting reagent waste significantly restrict the economic viability of the process. Especially when processing densely interbedded ores with similar mineral floatability, the existing process requires excessive copper sulfate dosage to compensate for the activation effect, further exacerbating the environmental and economic burden.

[0037] In addition, the application research of ethiocarbamate mostly focuses on the synergy between ethiocarbamate and other agents, and there is no application of a single collector to the activation of sphalerite.

[0038] Finally, although existing technologies for copper sulfate-free sphalerite activation have emerged, they require an extremely high amount of lime as a depressant. The resulting high-alkaline environment can easily lead to problems such as reagent waste, surface passivation, environmental risks, and decreased sorting efficiency during the flotation process.

[0039] In order to solve the above problems, in response to the dual environmental and economic pressures caused by traditional activation mechanisms, it is necessary to establish a new activation system that does not rely on copper sulfate. Studies have found that the interaction between collector molecules and mineral surfaces directly affects the activation effect. By screening non-xanthate collectors with selective adsorption capabilities and combining physical activation methods to enhance the adsorption kinetics of the agents, it is possible to break through the traditional activation mode. After systematic testing of thiocarbamate agents, it was found that ethiocarbamate can not only achieve preferential adsorption of copper minerals under a specific dosage gradient and a small amount of lime as an inhibitor, but also directly activate the active sites on the sphalerite surface under aerated stirring conditions, thereby constructing an activation path without the intervention of copper ions.

[0040] In response to the above problems, the embodiments of the present application provide a copper sulfate-free flotation separation method for copper-zinc sulfide ores, which overcomes the path of relying on copper sulfate to fully activate the zinc sulfide minerals in the traditional copper-zinc sulfide flotation process. By using low-concentration ethylthiocarbamate as the single collector for copper-zinc mixed flotation, low-dose lime as an inhibitor, mixed concentrate regrinding, copper tailings aeration and strong stirring, and adding high-concentration ethylthiocarbamate and low-dose lime to replace the traditional copper sulfate, the output of qualified copper concentrate and zinc concentrate products is achieved, the efficiency of copper-zinc ore dressing and separation is improved, and the defects of heavy metal pollution, high reagent cost, and process limitations are solved.

[0041] Please refer to Figure 1 , Figure 1 This is a process flow chart of a specific implementation method provided in this application.

[0042] The flotation separation method of copper-zinc sulfide ore without copper sulfate proposed in this application comprises the following steps:

[0043] Step 1: Obtain copper-zinc sulfide ore slurry.

[0044] Step 2: Using ethiocarbamate as a collector and lime as a depressant, the copper-zinc sulfide ore pulp is subjected to copper-zinc mixed flotation, wherein the amount of ethiocarbamate is 30g / t to 60g / t, and the amount of lime is 500g / t to 800g / t, to obtain a copper-zinc mixed concentrate and discardable tailings.

[0045] Step 3: Using zinc sulfate as an inhibitor, the copper-zinc mixed concentrate is regrinded to obtain copper-zinc mixed concentrate slurry.

[0046] Step 4: performing copper flotation on the copper-zinc mixed concentrate slurry to obtain copper concentrate and copper tailings slurry.

[0047] Step 5: Using ethylthiocarbamate as a collector, the copper tailings slurry is subjected to sphalerite activation under aeration and stirring conditions, wherein the amount of ethylthiocarbamate used is 200 g / t to 350 g / t to obtain activated sphalerite slurry.

[0048] Step 6: Using lime as a depressant, the activated sphalerite is floated, with the amount of lime being 200 g / t to 500 g / t, to obtain zinc concentrate.

[0049] Among them, ethylthiocarbamate as a collector refers to a thiocarbamate compound. The thiol group contained in its molecular structure forms a stable complex with the metal ions on the surface of the mineral. The ethylthiocarbamate molecule contains a thiocarbamic acid group (-NC=S) and an ethyl hydrophobic group. The sulfur atom and the nitrogen atom in the amino group can provide coordination sites to form a stable complex with the metal ions (such as Cu) on the surface of the sulfide mineral. 2+ , Pb 2+ 、Zn 2+ etc.) to form a complex.

[0050] During the copper-zinc mixed flotation, low concentration (30g / t~60g / t) of ethylthiocarbamate is used to achieve selective adsorption of copper-zinc sulfide ore pulp. During sphalerite activation, high concentration (200g / t~350g / t) of ethylthiocarbamate is used to cover the active sites on the sphalerite surface, that is, the thiocarbamic acid group (-N-CS-O-) in the ethylthiocarbamate molecule can react with the zinc ions (Zn) on the surface of sphalerite (ZnS). 2+ ) or copper ions formed after activation (Cu 2+ ) undergoes chemical adsorption, and ethylthiocarbamate undergoes chemical adsorption on the surface of sphalerite to generate stable thiocarbamate metal salts (such as Zn- or Cu-ethylthiocarbamate), which has the effect of inhibiting mineral oxidation and enhancing floatability.

[0051] The traditional process relies on copper sulfate (CuSO4) through Cu2 + Replacement of ZnS on the surface of sphalerite n2+ To generate CuS activation layer, 200-600g / t copper sulfate needs to be added, resulting in CuS content in the mineral processing wastewater. 2+ The innovation of this application is to use high concentration of ethiocarbamate (200-350g / t) and low dose of lime. Under the condition of aeration and stirring, the thiocarbamic acid group (-NC=S) in its molecule directly reacts with the Zn2 + or Fe 2+ (Fe sphalerite) forms a stable Zn / Fe-ethylthiocarbamate complex to build a hydrophobic layer. Low dose of lime maintains an alkaline environment of pH11 to pH12. This process does not require Cu 2+ After intervention, no copper ions were detected in the wastewater, and the source of heavy metal pollution was eradicated.

[0052] Specifically, this application activates sphalerite in a copper tailings slurry under aerated agitation. The aerated agitation generates high shear forces, stripping the sphalerite surface oxide layer and exposing fresh active sites. Ethiocarbamate molecules rapidly cover the mineral surface through turbulent diffusion, achieving saturated adsorption and ensuring sufficient ethiocarbamate adsorption on the fresh active sites. This allows ethiocarbamate to preferentially bind to sphalerite, inhibiting the flotation of gangue minerals such as pyrite, and improving the grade of the zinc concentrate.

[0053] Lime as an inhibitor refers to adjusting the pH value of the slurry to an alkaline environment, which promotes the formation of a hydrophilic hydroxyl oxide film on the surface of the zinc mineral. In the present application, 500g / t to 800g / t of lime is used as an inhibitor of pyrite during copper-zinc mixed flotation. On the one hand, it maintains an alkaline environment (pH 11 to 12) and reacts with the surface of zinc minerals (such as sphalerite ZnS) to generate hydrophilic zinc oxyhydroxide (Zn(OH)2) or zinc hydroxysulfate (Zn(OH)SO4), which inhibits the surface activity of sphalerite and other minerals and hinders the binding of zinc minerals to collectors. On the other hand, it is used to oxidize pyrite to form Fe(OH)3 colloid and neutralize acidic components in the slurry (such as dissolved CO2 and sulfide oxidation products). This application adopts a phased lime addition strategy, adding 500-800 g / t in the copper-zinc mixed flotation. Its core purpose is to quickly establish an alkaline environment with an initial pH of 11-12, quickly generate high-concentration hydroxyl ions, and inhibit zinc minerals. 200-500 g / t is added to the flotation-activated sphalerite to compensate for the hydroxyl ions consumed by the reaction, ensure pH stability, and maintain the inhibitory effect. Compared with the prior art, the lime used in this application is approximately 1: (3-9) of the prior art. This can prevent excessive hydroxyl ions from forming flocs with clay minerals in the slurry, prevent the problems of abnormal slurry viscosity, slowed flotation speed, and uncontrolled foam stability, thereby improving the enrichment effect of the concentrate.

[0054] Zinc sulfate as an inhibitor inhibits the floating of residual zinc minerals through competitive adsorption of zinc ions. Regrinding involves fine grinding of the mixed concentrate to increase the degree of dissociation of the mineral monomers. Fine particle size control can be achieved using a vertical stirred mill. Activation treatment under aerated agitation conditions enhances the diffusion rate of the reagent through the synergistic effect of gas diffusion and mechanical shear, promoting the directional adsorption of ethiocarbamate on the sphalerite surface.

[0055] The flotation separation method of the present application achieves dual functions by regulating the concentration of ethionamide and the reaction environment in stages. In the mixed flotation stage, low-concentration ethionamide is preferentially adsorbed on the surface of copper minerals, and is combined with lime to inhibit zinc minerals to achieve preliminary separation. In the regrinding treatment stage, zinc sulfate further inhibits undissociated zinc minerals to ensure copper flotation efficiency. During the treatment of copper tailings, high-concentration ethionamide is rapidly adsorbed on the surface of sphalerite in the turbulent flow field formed by aeration and stirring, forming a hydrophobic membrane structure to replace the traditional copper sulfide activation layer. Finally, the residual copper minerals are secondary suppressed by lime to achieve selective recovery of zinc minerals.

[0056] Compared to existing technologies, which rely on copper sulfate to form a copper sulfide activation layer on the sphalerite surface, this method directly creates a hydrophobic surface using collector molecules, avoiding the need for copper ion intervention. While existing technologies require the addition of copper sulfate and a xanthate collector prior to zinc flotation, this application achieves the dual goals of copper-zinc separation and sphalerite activation through the phased addition of a single reagent. Furthermore, sphalerite activation through aeration and agitation combined with high concentrations of ethiocarbamate enhances reagent adsorption efficiency through physical means, achieving flotation separation of copper-zinc sulfide ores without copper sulfate.

[0057] This application further proposes a specific method for obtaining copper-zinc sulfide ore slurry, including grinding the copper-zinc sulfide ore until 65% to 72% of the material particle size is less than 74 μm. Grinding 65% to 72% of the material particle size in the copper-zinc sulfide ore to within 74 microns can solve the problem of dissociation difficulties caused by the dense distribution of copper-zinc sulfide ore. By optimizing the grinding process parameters, the mineral particles are achieved in an ideal dissociation state. This particle size control not only ensures the selective adsorption efficiency of the ethionamide collector in the subsequent mixed flotation, but also maintains the appropriate rheological properties of the slurry, providing a basic guarantee for a clean flotation process without the involvement of copper sulfate.

[0058] The present application further proposes that the ore of the copper-zinc sulfide ore is a mixture of copper sulfide minerals and zinc sulfide minerals, wherein the copper sulfide minerals include at least one of chalcopyrite, covellite, bornite and tetrahedrite, and the zinc sulfide minerals include sphalerite and ferroalloy, and the ferroalloy has an iron content of 4% to 12%. By selecting ferroalloy with a specific iron content, its inherent surface chemical properties are utilized to achieve direct adsorption of the collector. The existing technology requires an additional amount of copper sulfate to compensate for the interference of iron on the activation effect when treating high-iron sphalerite. However, the present application limits the range of iron content to achieve the best matching state between the mineral surface active sites and the collector molecules, fundamentally eliminating the dependence on copper sulfate.

[0059] The present application further proposes a specific implementation method for copper-zinc mixed flotation, which includes sequentially performing one roughing selection, at least one cleaning selection, and at least one scavenging selection. The copper content of the copper-zinc mixed concentrate obtained by the scavenging selection is 8% to 12%, and the zinc content is 8% to 15%. The copper content of the discarded tailings is less than 0.2%, and the zinc content is less than 0.5%.

[0060] Specifically, after achieving initial enrichment of copper and zinc minerals through roughing, the concentrating stage further removes entrained gangue minerals, raising the copper and zinc grades of the mixed concentrate to 8%-12% and 8%-15%. This grade range prevents excessive oxidation of the sphalerite surface and reduces the amount of inhibitors required in subsequent separation processes. Scavenging treatment recycles the roughing tailings, controlling their copper and zinc contents to below 0.2% and 0.5%, respectively, ensuring that the tailings can be directly discarded without wasting resources. The synergistic effect of the multi-stage sorting process ensures that the copper-zinc mixed flotation process maintains sorting efficiency while providing an intermediate product with a stable mineral surface state for the subsequent copper sulfate-free zinc activation process.

[0061] Through the above technical solution, the present application achieves efficient separation in the copper-zinc mixed flotation stage, the copper and zinc content of the mixed concentrate is stabilized within the processable range, the metal loss rate of the tailings is significantly reduced, and a qualified intermediate product is provided for the subsequent copper sulfate-free sphalerite activation process, while reducing the waste of resources caused by excessive metal content in the tailings.

[0062] The present application further proposes a technical solution in which both ethionamide and lime are added before the first roughing in the copper-zinc mixed flotation stage.

[0063] Specifically, ethylthiocarbamate is added at the front end of the roughing process to preferentially adsorb the copper mineral surface by virtue of its selective capture characteristics. At this time, the pH of the slurry is rapidly raised to the range of 11 to 12 in combination with the amount of lime added, effectively inhibiting the activation of the surface potential of sphalerite. While ensuring the recovery rate of copper minerals, the total lime consumption is controlled below 800g / t. The molecular structure of ethylthiocarbamate is closely related to the metal sites on the surface of sulfide minerals (such as Cu 2+ 、Zn 2+ ) has a stronger affinity, thereby reducing the amount of inhibitor used.

[0064] Compared with existing technologies, traditional processes typically use a crude, one-time addition of collectors and excess lime during the copper-zinc flotation stage, resulting in reagent waste and a burden on subsequent wastewater treatment. This method reduces total lime usage by 20%-50% while maintaining effective inhibition. Compared to existing technologies that still require the addition of zinc sulfate in the concentration stage, this method completely eliminates the need for zinc inhibitors.

[0065] Through the above technical solution, the present application achieves efficient enrichment of copper minerals and deep suppression of zinc minerals in the copper-zinc mixed flotation stage, stably improving the copper grade of the mixed concentrate to the range of 8%-12%, while reducing the copper loss rate of the tailings to below 0.2%, creating suitable slurry rheological conditions for the subsequent regrinding process.

[0066] The present application further proposes that in step S3, the amount of zinc sulfate used is 200 g / t to 300 g / t, and the copper-zinc mixed concentrate is regrinded by grinding the copper-zinc mixed concentrate using a vertical stirred mill or an overflow ball mill until 85% to 90% of the material particle size is less than 26 microns.

[0067] Specifically, zinc ions generated by the dissociation of zinc sulfate in the slurry preferentially adsorb to the sphalerite surface, blocking copper ion activation sites through competitive adsorption. When the zinc sulfate dosage is less than 200 g / t, a complete coating cannot form, resulting in sphalerite being mistakenly captured in subsequent copper flotation. Above 300 g / t, the excess zinc sulfate reacts with calcium ions to form calcium sulfate colloids, increasing slurry viscosity and worsening the separation environment. Vertical stirred mills preferentially break up the interface between copper minerals and sphalerite through high-frequency shear between the media layers, while overflow ball mills rely on the impact grinding action of steel balls to gradually dissociate dense inclusions. Controlling the particle size to 85% to 90% below 26 microns satisfies the requirements for chalcopyrite dissociation while preventing over-grinding of the sphalerite, which could potentially adsorb collectors on new surfaces.

[0068] Through the above technical solution, this application achieves a synergistic effect by forming a zinc mineral surface inhibition layer and fully dissociating the minerals during the regrinding stage of the copper-zinc mixed concentrate, solving the problem of low copper-zinc separation efficiency caused by sphalerite activation in traditional processes. The controlled dosage of zinc sulfate effectively blocks the active sites on the sphalerite surface, the equipment selection of a vertical stirred mill or overflow ball mill is adapted to the different mineral embedding characteristics, and the material particle size threshold ensures a balance between copper mineral recovery and zinc mineral inhibition, ultimately achieving efficient copper-zinc separation without the addition of copper sulfate.

[0069] The present application further proposes a copper flotation process, which includes performing a roughing process and at least one cleaning process in sequence to obtain a copper concentrate with a copper content greater than 18% and a zinc content less than 5%, and a copper tailings with a copper content less than 1.5% and a zinc content greater than 10%.

[0070] Specifically, the roughing stage involves preliminary separation of the copper-zinc mixed concentrate, prioritizing copper minerals in an alkaline environment created by lime. Ethiocarbamate selectively adsorbs on the surface of the copper minerals, forming a hydrophobic layer. The roughing stage involves multiple purifications of the copper concentrate, gradually removing the contaminated zinc minerals by reducing the collector dosage in a stepwise manner and maintaining a high alkalinity environment. A copper concentrate with a zinc content below 5% is achieved through two or more stages of concentrating, for example, by adding a trace amount of lime during the second stage to enhance zinc mineral suppression and maintain the required alkaline environment. A copper tailings zinc content above 10% is achieved by controlling the roughing recovery rate, for example by limiting the roughing time to 3 to 5 minutes, so that any uncaptured zinc minerals are fully retained in the tailings.

[0071] This application establishes a control standard for copper tailings with a zinc content exceeding 10%, allowing unrecovered sphalerite to maintain natural floatability in the slurry without relying on copper sulfate for surface modification. In existing technologies, the zinc content of copper concentrate generally ranges from 6% to 8%, requiring additional impurity removal steps in the subsequent smelting process. However, this application reduces the zinc content to below 5% through multi-stage concentrating, directly meeting the smelting raw material standard.

[0072] Through the above technical solution, this application effectively improves the selectivity of copper-zinc separation, reducing the zinc impurity content in the copper concentrate to a level suitable for direct smelting, while ensuring that the zinc minerals in the tailings retain sufficient natural floatability. This process eliminates the addition of copper sulfate while still achieving efficient recovery of zinc minerals in subsequent flotation operations, solving the activator dependency issue caused by the traditional process's insufficient separation precision.

[0073] The present application further proposes that when the sphalerite is activated on the copper tailings slurry under the condition of aeration and stirring, the aeration volume is controlled at 0.05-0.20 m 3 / h, the stirring speed is controlled at 650-1000r / min, and the stirring time is controlled at 4-6min.

[0074] Specifically, the inflation volume is set to 0.05~0.20m 3 / h, for example, 0.10m 3A median parameter of 1000 rpm / h maintains the dissolved oxygen concentration in the slurry within a range of 0.5 to 1.2 mg / L, promoting the formation of an oxide layer on the sphalerite surface and exposing active sites. Maintaining a stirring speed between 650 and 1000 rpm, for example, an intermediate value of 800 rpm, generates sufficient shear force to disperse the ore particles while avoiding exceeding the critical speed and causing slurry splashing. Controlling the stirring time between 4 and 6 minutes, for example, 5 minutes, ensures that ethiocarbamate molecules stably coat the sphalerite surface through physical adsorption and chemical bonding. Under aerated stirring conditions, high concentrations of ethiocarbamate replace the traditional copper sulfate ion exchange activation mechanism. By precisely controlling the physicochemical environment of the slurry, ethiocarbamate directly reacts with the sphalerite surface to form a hydrophobic adsorption layer.

[0075] Compared with the existing technology, the traditional method relies on copper sulfate to form a copper sulfide activation film on the surface of sphalerite, which consumes 200 to 600 g / t of copper sulfate and produces copper-containing wastewater. The present application optimizes the aeration and stirring conditions and utilizes the oxidation-adsorption synergistic mechanism to achieve effective activation of sphalerite without the addition of copper sulfate. For example, in the prior art, a high alkaline environment of PH12 needs to be maintained during the activation stage to inhibit pyrite, and an excess of lime is required as a supplement to maintain the PH at 12 in real time. However, high pH will accelerate the hydrolysis and precipitation of copper sulfate, increase the viscosity of the slurry, and result in a decrease in the actual activation efficiency. The present application can complete the activation under the conditions of PH10 to PH11, avoiding the additional reagent consumption caused by PH adjustment.

[0076] This application completely eliminates the use of copper sulfate in the sphalerite activation process, solving the problem of heavy metal pollution sources in traditional processes. Copper ions are no longer introduced into the slurry, which reduces the cost of wastewater treatment by about 30% to 50%, while avoiding the loss of reagents caused by the hydrolysis of copper sulfate. The stirring energy consumption in the activation stage is maintained in the range of 0.8 to 1.2 kWh / t, which is comparable to the energy consumption level of conventional mechanical stirring processes, achieving environmental benefits without increasing energy consumption. The slurry flow stability is improved, and the uniformity of the suspension of mineral particles in the activation tank is increased by about 20%, which is conducive to the stable operation of subsequent flotation operations.

[0077] The present application further proposes to sequentially perform a roughing process, a scavenging process and at least one concentrating process on the activated sphalerite to finally obtain a zinc concentrate with a zinc content exceeding 45%. Furthermore, lime is added during the first concentrating process.

[0078] Specifically, the selective adsorption characteristics of ethionamide are used in the roughing stage to preferentially capture sphalerite after surface activation, thereby achieving preliminary enrichment of zinc minerals. In the scavenging stage, the roughing tailings are subjected to secondary treatment, and the sphalerite with a low degree of activation is promoted to float by strengthening the aeration and stirring intensity of the slurry, thereby reducing metal loss. In the concentrating stage, a multi-stage flotation cell series structure is adopted, and residual copper sulfide minerals are suppressed by lime in an alkaline environment, thereby gradually improving the grade of the zinc concentrate. Through process connection and synergistic action of reagents, each process forms a complete zinc mineral recovery system without the participation of copper sulfate. This application optimizes the flotation process structure and reagent addition method, directly utilizes the capture function of ethionamide to replace the chemical activation effect of copper sulfate in the roughing stage, strengthens the physical activation effect in the scavenging stage, and uses lime to suppress interfering minerals in the concentrating stage, thereby constructing a sorting environment that does not require exogenous copper ions, eliminating the risk of wastewater copper ion contamination caused by the use of copper sulfate, and avoiding the problem of copper sulfate reagent efficiency attenuation in a high-alkali environment. At the same time, the total consumption of activation reagents is reduced through process optimization. The graded flotation system can achieve efficient recovery of sphalerite while ensuring that the grade of zinc concentrate meets the standards.

[0079] In summary, this application achieves efficient and clean separation of copper-zinc sulfide ores by enriching copper at a low concentration and activating zinc at a high concentration with ethionylthiocarbamate, quickly establishing an alkaline environment with a low dose of lime, and dynamically replenishing hydroxyl ions, thus completing zero heavy metal pollution in flotation separation, completely getting rid of dependence on copper sulfate, and eliminating Cu2 + It has strong process universality, can adapt to complex embedded ores, is easy to operate and has broad prospects for industrial application.

[0080] The beneficial effects of the present invention will be further illustrated below with reference to the examples.

[0081] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0082] It should be noted that the raw materials of the copper-zinc sulfide ore involved in this application come from a large copper-zinc mine in the Dominican Republic. The large copper-zinc mine is a large sulfide copper-zinc mine. The average copper content of the ore produced by the mine is 2.34%, zinc is 2.88%, sulfur is 33.30%, gold is 1.30 g / t, and silver is 41.50 g / t. The large copper-zinc mine is a typical high-sulfur copper-zinc-gold-silver polymetallic mine. The copper in the ore is mainly found in primary copper sulfide (chalcopyrite) and secondary copper sulfide (covellite, blue chalcocite) minerals, with distribution rates of 80.36% and 17.86% respectively. Zinc is mainly produced in the form of zinc sulfide-sphalerite, with a distribution rate of 88.89%. After analysis, the results of the ore chemical multi-element analysis are shown in Table 1.

[0083] Table 1 Main chemical composition of ore (%)

[0084]

[0085]

[0086] Example 1

[0087] According to the attached Figure 1 The process flow shown processes the run-of-mine ore of the copper-zinc sulfide mine.

[0088] (1) The raw ore of the copper-zinc sulfide ore is subjected to coarse, medium and fine crushing to a particle size of 6 mm, and then transported to a ball mill for raw ore grinding. The overflow particle size is controlled to 74 μm, accounting for 70%, and the classified underflow is returned to the ball mill inlet. The overflow is pumped to a copper-zinc mixed flotation machine;

[0089] (2) Ethiocarbamate was added as a copper-zinc mixed flotation collector in a copper-zinc mixed flotation machine, and lime was added as a pyrite inhibitor. The amount of ethiocarbamate was 30 g / t and the amount of lime was 500 g / t. After a single roughing operation, the copper-zinc mixed concentrate produced had a copper content of 8.6% and a zinc content of 10.8%. The roughing tailings were subjected to a single scavenging operation. The copper content of the scavenged tailings was 0.21% and the zinc content was 0.34%. The scavenged tailings were directly transported to the tailings pond.

[0090] (3) The copper-zinc mixed concentrate is drained into an overflow ball mill for regrinding. The ball mill speed and the amount of steel balls added are controlled, and 300 g / t of zinc sulfate is added at the ball mill inlet to obtain a regrinding overflow product with a particle size of less than 26 μm, accounting for 88%, which is used for copper flotation operations;

[0091] (4) Copper flotation uses a single roughing and a single cleaning operation to obtain a copper concentrate with a copper content of 18.2% and a zinc content of 5.4% and a copper flotation tailing;

[0092] (5) The copper flotation tailings are pumped into an aerated stirring barrel for strong stirring. During the stirring process, 300 g / t of ethylthiocarbamate is added and the aeration volume in the stirring barrel is controlled to 0.15 m 3 / h, the impeller speed is set at 650r / min~1000r / min, and the overflow of the mixing barrel flows by gravity to the flotation column for zinc flotation operation;

[0093] (6) Zinc roughing operation includes one roughing and one fine separation. The air gun of flotation column is filled with 0.2m 3 / h, the thickness of the foam layer on the flotation column is 10cm, and the foam layer is drawn out as zinc coarse concentrate by gravity. The bottom flow of the coarse flotation column is tailings and is discarded. The zinc coarse concentrate is drained to the fine flotation column. The lime of 300g / t is added to the fine flotation column. The air gun of the fine flotation column is inflated with an air volume of 0.1m 3 / h, the height of the flotation column foam layer is 8cm, the foam layer is drawn out as zinc concentrate by gravity, and the bottom flow of the concentration flotation column is drained into the roughing flotation column.

[0094] The obtained copper and zinc flotation beneficiation indicators are shown in Table 2.

[0095] Table 2 Ore dressing and separation indexes of Example 1 (%)

[0096]

[0097]

[0098] It can be seen that the copper content of the obtained copper concentrate is 18.2% and the zinc content is 5.4%, the copper content of the zinc concentrate is 3.66% and the zinc content is 48.44%, the zinc recovery rate in the zinc concentrate reaches 65.24%, and the copper recovery rate in the copper concentrate is 82.04%.

[0099] The average usage of copper sulfate on site is 0. The mineral processing wastewater produced on site was tested and no free copper ions were detected in the water.

[0100] After applying this embodiment 1, the cost of copper sulfate that can be saved per month is shown in Table 3.

[0101] Table 3 Copper sulfate cost savings

[0102]

[0103] Example 2

[0104] The difference between Example 2 and Example 1 is that, in Example 2, the amount of ethionamide added to the copper-zinc mixed flotation machine is 60 g / t, and the amount of lime added is 800 g / t.

[0105] The obtained copper and zinc flotation beneficiation indicators are shown in Table 4.

[0106] Table 4 Ore dressing and separation index after Example 2 (%)

[0107]

[0108] It can be seen that the copper content of the obtained copper concentrate is 17.64% and the zinc content is 5.43%, the copper content of the zinc concentrate is 3.23% and the zinc content is 47.05%, the zinc recovery rate in the zinc concentrate reaches 65.73%, and the copper recovery rate in the copper concentrate is 79.54%.

[0109] The average usage of copper sulfate on site is 0. The mineral processing wastewater produced on site was tested and no free copper ions were detected in the water.

[0110] Example 3

[0111] The difference between Example 3 and Example 1 is that the copper flotation tailings in Example 3 are pumped into an aerated stirring barrel for vigorous stirring, 350 g / t of ethionamide is added during the stirring process, and 500 g / t of lime is added to the select flotation column.

[0112] The obtained copper and zinc flotation beneficiation indicators are shown in Table 5.

[0113] Table 5 Ore dressing and separation index after Example 3 (%)

[0114]

[0115] It can be seen that the copper content of the obtained copper concentrate is 18.1% and the zinc content is 5.31%, the copper content of the zinc concentrate is 2.93% and the zinc content is 49.83%, the zinc recovery rate in the zinc concentrate reaches 65.89%, and the copper recovery rate in the copper concentrate is 81.30%.

[0116] The average usage of copper sulfate on site is 0. The mineral processing wastewater produced on site was tested and no free copper ions were detected in the water.

[0117] Example 4

[0118] The difference between Example 4 and Example 1 is that the copper flotation tailings are pumped into an aerated stirring barrel for vigorous stirring, 250 g / t of ethionamide is added during the stirring process, and 200 g / t of lime is added to the select flotation column.

[0119] The obtained copper and zinc flotation beneficiation indicators are shown in Table 6.

[0120] Table 6 Ore dressing and separation index after Example 4 (%)

[0121]

[0122]

[0123] It can be seen that the copper content of the obtained copper concentrate is 18.43% and the zinc content is 5.16%, the copper content of the zinc concentrate is 3.04% and the zinc content is 42.98%, the zinc recovery rate in the zinc concentrate reaches 65.72%, and the copper recovery rate in the copper concentrate is 80.06%.

[0124] The average usage of copper sulfate on site is 0. The mineral processing wastewater produced on site was tested and no free copper ions were detected in the water.

[0125] Comparative Example 1

[0126] In order to further verify the application effect of the present invention on a certain copper-zinc sulfide ore in Dominica, a comparative test was carried out during the implementation of the present invention. Figure 2The ore is processed by the process flow shown (i.e., the prior art), 300 g / t of copper sulfate is added to the copper tailings as an activator for sphalerite, and after sufficient activation, 120 g / t of butyl xanthate is added as a collector for sphalerite. The on-site sorting production indicators are shown in Table 7.

[0127] Table 7 Ore dressing and separation indexes of comparative example 1 (%)

[0128]

[0129] The copper content of the obtained copper concentrate is 18.22% and the zinc content is 5.33%. The copper content of the zinc concentrate is 3.62% and the zinc content is 43.24%. The zinc recovery rate in the zinc concentrate reaches 60.62%, and the copper recovery rate in the copper concentrate is 81.91%.

[0130] The average amount of copper sulfate used on site is 300g / t. The mineral processing wastewater produced on site was tested and the free copper ion content in the water was determined to be 2.11mg / L.

[0131] Comparative Example 2

[0132] In order to further verify the application effect of the present invention on a certain copper-zinc sulfide ore in Dominica, a comparative test was carried out during the implementation of the present invention. The difference between Comparative Example 2 and Example 1 is that the steps implemented in step (5) of Comparative Example 3 are as follows:

[0133] (5) The copper flotation tailings are pumped into an aerated stirring barrel for vigorous stirring. During the stirring process, 300 g / t of ethylthiocarbamate is added, the aeration valve is closed (the aeration volume is 0), and the stirring impeller speed is reduced to 250 r / min to 400 r / min through the frequency modulation device. The overflow of the stirring barrel flows by gravity into the flotation column for zinc flotation operation.

[0134] The obtained copper and zinc flotation beneficiation indicators are shown in Table 8.

[0135] Table 8 Ore dressing and separation index (%) obtained in comparative example 2

[0136]

[0137] The copper content of the obtained copper concentrate is 18.08% and the zinc content is 5.14%. The copper content of the zinc concentrate is 3.78% and the zinc content is 48.22%. The zinc recovery rate in the zinc concentrate reaches 33.89%, and the copper recovery rate in the copper concentrate is 80.22%.

[0138] The average amount of copper sulfate used on site is 0. The mineral processing wastewater produced on site was tested and the content of free copper ions in the water was found to be undetectable.

[0139] Comparative Example 3

[0140] In order to further verify the application effect of the present invention on a certain copper-zinc sulfide ore in Dominica, a comparative test was carried out during the implementation of the present invention. The difference between Comparative Example 3 and Example 1 is that the steps implemented in step (5) of Comparative Example 3 are as follows:

[0141] (5) The copper flotation tailings are pumped into an aerated stirring barrel for strong stirring. No reagents are added during the stirring process (the amount of ethionamide is 0), and the aeration volume in the stirring barrel is controlled to 0.15m 3 / h, the stirring impeller speed is 650r / min~1000r / min, and the overflow of the stirring barrel flows to the flotation column for zinc flotation operation;

[0142] The other process steps are the same as in Example 1.

[0143] The obtained copper and zinc flotation beneficiation indicators are shown in Table 9.

[0144] Table 9 Ore dressing and separation index (%) obtained in comparative example 3

[0145]

[0146]

[0147] The copper content of the obtained copper concentrate is 18.18% and the zinc content is 5.34%. The copper content of the zinc concentrate is 3.78% and the zinc content is 44.55%. The zinc recovery rate in the zinc concentrate reaches 42.20%, and the copper recovery rate in the copper concentrate is 80.21%.

[0148] The average amount of copper sulfate used on site is 0. The mineral processing wastewater produced on site was tested and the content of free copper ions in the water was found to be undetectable.

[0149] Comparative Example 4

[0150] In order to further verify the application effect of the present invention on a certain copper-zinc sulfide ore in Dominica, a comparative test was carried out during the implementation of the present invention. The difference between Comparative Example 4 and Example 1 is that the steps implemented in step (5) of Comparative Example 4 are as follows:

[0151] (5) The copper flotation tailings are pumped into an aerated stirring barrel for strong stirring. No reagents are added during the stirring process (the dosage of ethionamide is 30 g / t), and the aeration volume in the stirring barrel is controlled at 0.15 m 3 / h, the stirring impeller speed is 650r / min~1000r / min, and the overflow of the stirring barrel flows to the flotation column for zinc flotation operation;

[0152] The other process steps are the same as in Example 1.

[0153] The obtained copper and zinc flotation beneficiation indicators are shown in Table 10.

[0154] Table 10 Ore dressing and separation indexes obtained in comparative example 4 (%)

[0155]

[0156] The copper content of the obtained copper concentrate is 18.03% and the zinc content is 5.23%. The copper content of the zinc concentrate is 3.04% and the zinc content is 45.32%. The zinc recovery rate in the zinc concentrate reaches 46.70%, and the copper recovery rate in the copper concentrate is 80.60%.

[0157] The average amount of copper sulfate used on site is 0. The mineral processing wastewater produced on site was tested and the content of free copper ions in the water was found to be undetectable.

[0158] Comparative Example 5

[0159] In order to further verify the application effect of the present invention on a certain copper-zinc sulfide ore in Dominica, a control test was carried out during the implementation of the present invention. The difference between Comparative Example 5 and Example 1 is that the amount of lime used in step (2) and step (6) of Comparative Example 4 is 2000 g / t.

[0160] The other process steps are the same as in Example 1.

[0161] The obtained copper and zinc flotation beneficiation indicators are shown in Table 11.

[0162] Table 11 Ore dressing and separation index (%) obtained in comparative example 5

[0163]

[0164] The copper content of the obtained copper concentrate is 17.85% and the zinc content is 5.71%. The copper content of the zinc concentrate is 3.44% and the zinc content is 46.22%. The zinc recovery rate in the zinc concentrate reaches 49.54%, and the copper recovery rate in the copper concentrate is 79.81%.

[0165] The average amount of copper sulfate used on site is 0. The mineral processing wastewater produced on site was tested and the content of free copper ions in the water was found to be undetectable.

[0166] As can be seen from Example 1, the present invention can reduce the copper sulfate cost investment by US$64,350 per month. This cost does not include the purchase and installation of equipment such as the dosing device, conveying pipeline, motor and control device for preparing the copper sulfate solution, and related power consumption costs, etc., which are reduced in on-site production. At the same time, the free copper ion content in the mineral processing wastewater is reduced from 2.11 mg / L to undetectable, which has good economic and environmental benefits.

[0167] Example 1: In copper-zinc mixed flotation, 30 g / t of ethiocarbamate and 500 g / t of lime were used, and in sphalerite activation, 300 g / t of ethiocarbamate and 300 g / t of lime were used for flotation separation. The results were copper and zinc flotation separation with a copper recovery rate of 82.04%, a zinc recovery rate of 65.24%, a zinc concentrate grade of 48.44%, and a zinc impurity content of 5.4% in the copper concentrate. No copper ions were detected in the wastewater, and the amount of copper sulfate used was 0.

[0168] In Example 2, in the copper-zinc mixed flotation, the ethionine content was increased to 60 g / t and the lime content was increased to 800 g / t. The copper recovery rate after flotation separation slightly decreased to 79.54%, while the zinc recovery rate slightly increased to 65.73%. This shows that excessive reagents in the mixed flotation stage will inhibit the adsorption of copper minerals, but the zinc activation effect is better.

[0169] In Example 3, the concentration of ethiocarbamate was increased to 350 g / t and the concentration of lime was increased to 500 g / t in sphalerite activation. The grade of the zinc concentrate after flotation separation increased to 49.83%, and the zinc recovery rate was 65.89% (the highest value of Examples 1 to 4). This shows that high concentration of ethiocarbamate enhances sphalerite activation, but the amount of lime needs to be controlled to prevent excessive inhibition.

[0170] In Example 4, in sphalerite activation, the concentrations of ethionamide and lime were reduced to 250 g / t and 200 g / t, respectively. The zinc concentrate grade after flotation separation dropped to 42.98%, but the recovery rate still reached 65.72%. This demonstrates the necessity of a large dose of ethionamide to ensure saturated adsorption of sphalerite.

[0171] Comparative Example 1 is a traditional copper sulfate process, and uses butyl xanthate as a collector for sphalerite. The zinc recovery rate after flotation separation is only 60.62%, and the copper recovery rate is 81.91%. At the same time, the wastewater contains 2.11 mg / L of copper ions, and the copper sulfate dosage is 300 g / t.

[0172] It can be seen that compared with Examples 1 to 4, the flotation separation method provided in the present application can, on the one hand, completely avoid copper ion contamination of the water body, and on the other hand, improve the zinc recovery rate.

[0173] Compared with Example 1, the key difference in Comparative Example 2 is that the aeration stirring is turned off and a lower rotation speed is used for zinc flotation. The zinc recovery rate after flotation separation drops sharply to 33.89%. This fully demonstrates that aeration stirring is one of the keys to activation. The synergistic effect of gas diffusion and mechanical shearing enhances the diffusion rate of the reagent and promotes the directional adsorption of ethionamide on the surface of sphalerite.

[0174] Compared with Example 1, in Comparative Example 3, no ethiocarbamate was added during sphalerite activation, and the zinc recovery rate after flotation separation was only 42.20%, which verified that ethiocarbamate was the core of sphalerite activation.

[0175] In addition, the reason why the zinc recovery rate of the zinc tailings in Comparative Example 2 is significantly different from that in Comparative Example 1 or Example 1 is that Comparative Example 2 does not use aeration stirring, resulting in a large amount of sphalerite not being activated (accounting for more than 40%), so the zinc content in the zinc tailings exceeds 4%, and the zinc recovery rate lost in the zinc tailings is high. Similarly, the reason why the zinc recovery rate of the zinc tailings in Comparative Example 3 is significantly different is that the sphalerite was not activated.

[0176] In Comparative Example 4, compared with Example 1, the concentration of ethiocarbamate was reduced to 30 g / t during sphalerite activation, and the zinc recovery rate after flotation separation was 46.70%, which was still lower than that of Examples 1 to 4, but higher than that of Comparative Example 3. This shows that a high concentration of ethiocarbamate (≥200 g / t) is required in the activation stage, and a low dose cannot fully cover the mineral surface.

[0177] Comparative Example 5 Compared with Example 1, the amount of lime was increased to 2000 g / t in both copper-zinc mixed flotation and sphalerite activation. The zinc recovery rate after flotation separation dropped to 49.54%, which indicates that excessive lime inhibited the flotation of zinc minerals.

[0178] In summary, this application breaks through the traditional reliance on copper sulfate by activating sphalerite with ethiocarbamate and regulating lime in stages, achieving efficient and environmentally friendly separation of copper-zinc sulfide ores. The data from the examples show that precise control of process parameters (agent dosage, aeration and stirring) is the key to success, and the comparative examples verify the efficiency loss of deviation from the optimized conditions. This method is significantly superior to traditional processes in terms of environmental protection, cost, and sorting efficiency, and has broad prospects for industrialization.

[0179] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A flotation separation method for copper-zinc sulfide ore without copper sulfate, characterized in that: The following steps are involved: S1. Obtaining copper-zinc sulfide ore slurry; S2. Using ethiocarbamate as a collector and lime as a depressant, the copper-zinc sulfide ore pulp is subjected to copper-zinc mixed flotation, wherein the amount of ethiocarbamate used is 30 g / t to 60 g / t, and the amount of lime used is 500 g / t to 800 g / t, to obtain a copper-zinc mixed concentrate and discardable tailings; S3, regrinding the copper-zinc mixed concentrate using zinc sulfate as an inhibitor to obtain a copper-zinc mixed concentrate slurry; S4, performing copper flotation on the copper-zinc mixed concentrate slurry to obtain copper concentrate and copper tailings slurry; S5. Using ethylthiocarbamate as a collector, the copper tailings slurry is subjected to sphalerite activation under aeration and stirring conditions, wherein the amount of ethylthiocarbamate used is 200 g / t to 350 g / t to obtain an activated sphalerite slurry; S6. Using lime as a depressant, the activated sphalerite is floated, wherein the amount of lime used is 200 g / t to 500 g / t, to obtain zinc concentrate.

2. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 1, characterized in that: In step S1, obtaining the copper-zinc sulfide ore slurry is specifically as follows: The ore material containing copper sulfide and zinc sulfate is ground until 65% to 72% of the ore material has a particle size of less than 74 μm.

3. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 2, characterized in that: The ore containing copper sulfide and zinc sulfate is a mixture of copper sulfide minerals and zinc sulfide minerals, wherein the copper sulfide minerals include at least one of chalcopyrite, covellite, bornite and tetrahedrite, and the zinc sulfide minerals include sphalerite and / or marmatite, and the iron content of the marmatite is 4% to 12%.

4. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 1, characterized in that: In step S2, the copper-zinc mixed flotation is specifically as follows: Performing one roughing selection, at least one fine selection and at least one sweeping selection in sequence; The copper-zinc mixed concentrate contains 8% to 12% copper and 8% to 15% zinc; The copper content of the discardable tailings is less than 0.2%, and the zinc content is less than 0.5%.

5. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 4, characterized in that: In step S2, ethionamide and lime are both added before the first roughing.

6. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 1, characterized in that: In step S3, the amount of zinc sulfate used is 200 g / t to 300 g / t, and the copper-zinc mixed concentrate is regrinded as follows: The copper-zinc mixed concentrate is ground using a vertical stirred mill or an overflow ball mill until 85% to 90% of the material particles have a size of less than 26 μm.

7. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 1, characterized in that: In step S4, copper flotation is specifically as follows: Carry out one roughing process and at least one fine cleaning process in sequence; The copper concentrate has a copper content greater than 18% and a zinc content less than 5%; The copper tailings have a copper content of less than 1.5% and a zinc content of more than 10%.

8. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 1, characterized in that: In step S5, the aeration volume of the aeration stirring is 0.05-0.20 m 3 / h, stirring speed is 650r / min~1000r / min, and stirring time is 4min~6min.

9. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 1, characterized in that: In step S6, the activated sphalerite is subjected to flotation as follows: The activated sphalerite is subjected to a roughing separation, a scavenging separation and at least one concentrating separation in sequence; The zinc content of the zinc concentrate is greater than 45%.

10. The flotation separation method for copper-zinc sulfide ore without copper sulfate according to claim 9, characterized in that: In step S6, lime is added during the first concentration.

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