A method for recovering associated zinc from copper concentrate during copper smelting.

Abstract

This invention relates to a method for recovering associated zinc from copper concentrate during copper smelting, belonging to the field of non-ferrous metal smelting and mineral processing technology. The method includes: preparing and grinding copper concentrate to obtain a finely ground slurry; the -0.074 mm particles in the finely ground slurry constitute 92-95% of the total solid particles; mixing the finely ground slurry with a copper collector and a zinc inhibitor; the zinc inhibitor contains sulfur dioxide, and the mixing temperature of the zinc inhibitor and the finely ground slurry is 40-50°C; and using microbubble flotation technology to separate copper from zinc concentrate using flotation, obtaining copper concentrate and zinc concentrate; the foam diameter of the microbubble flotation is 30-80 μm. This invention achieves efficient inhibition of zinc minerals by controlling the copper flotation separation temperature, at which waste sulfur dioxide is used synergistically as a zinc inhibitor, further controlling the particle size of the fine grinding and the foam diameter during flotation, thus constructing an integrated copper-zinc separation and zinc recovery process.

Description

Technical Field

[0001] This invention relates to a method for recovering associated zinc from copper concentrate during copper smelting, belonging to the field of non-ferrous metal smelting and mineral processing technology. Background Technology

[0002] Copper concentrate is the core raw material for copper smelting, and the zinc content in industrially used copper concentrate is generally 2% to 3%. In the traditional copper smelting process, zinc is easily volatilized and lost with slag due to its fine particle size and close association with copper minerals. As a result, the overall zinc recovery rate in the entire copper smelting industry chain is only 17%, and a large amount of valuable zinc resources are wasted, failing to achieve full utilization of this valuable metal.

[0003] Existing copper-zinc separation technologies mainly focus on zinc suppression and copper flotation during the mineral processing stage. Commonly used zinc inhibitors include chemical reagents such as zinc sulfate, sodium sulfite, and sodium metabisulfite. However, these technologies suffer from several key problems: First, purchased inhibitors are expensive (single-agent dosage is typically ≥100 g / t), and their addition easily causes secondary pollution and is difficult to degrade. Second, traditional processes often use external heat sources to heat the slurry, resulting in low energy efficiency and increased energy costs. Third, for finely intercalated copper-zinc aggregates, traditional grinding processes do not provide sufficient dissociation, limiting subsequent flotation separation efficiency and hindering efficient zinc recovery. Fourth, existing technologies primarily target the recovery of valuable metals from byproducts such as copper smelting slag and electrolytic dust, employing complex processes like plasma spraying and continuous leaching, which are cumbersome and require significant equipment investment. No specific recovery scheme has been designed for the low zinc content in the copper concentrate pretreatment stage.

[0004] Meanwhile, copper smelting generates a large amount of flue gas containing sulfur dioxide. In existing technologies, this flue gas is mainly used to produce sulfuric acid, and some low-concentration flue gas is directly discharged after desulfurization, without realizing in-situ resource utilization. Furthermore, the waste heat from steam generated by the smelting system is mostly discharged in the form of condensate, resulting in serious energy waste, which is inconsistent with the development concept of green metallurgy.

[0005] Therefore, it is of great significance to develop a method for deep dissociation and efficient separation of copper and zinc. Summary of the Invention

[0006] To address the problems of low zinc recovery rate, high cost and low energy utilization of zinc inhibitors in existing technologies, underutilization of smelting waste, and lack of specificity in existing recovery processes, the present invention aims to provide a method for recovering associated zinc from copper concentrate during copper smelting. This method utilizes the waste heat from steam generated during copper smelting to control the temperature of the mixture of zinc inhibitor and finely ground slurry. At this temperature, waste sulfur dioxide is used synergistically as a zinc inhibitor to achieve efficient inhibition of zinc minerals. Furthermore, the particle size of the fine grinding and the foam diameter during flotation are controlled, thus constructing an integrated copper-zinc separation and zinc recovery process.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for recovering associated zinc from copper concentrate during copper smelting, the method comprising:

[0008] (1) Copper concentrate is slurried and ground to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 92~95% of the total solid particles;

[0009] (2) The finely ground slurry is mixed with a copper collector and a zinc inhibitor; the zinc inhibitor contains sulfur dioxide, and the temperature of the mixing process between the zinc inhibitor and the finely ground slurry is 40~50℃;

[0010] (3) The copper slurry from step (2) is separated by microbubble flotation to obtain copper concentrate and zinc concentrate; the diameter of the microbubble flotation froth is 30~80 μm.

[0011] Addressing the characteristic of finely embedded copper concentrate particles, this invention first strictly controls the grinding fineness of the prepared slurry to 92%~95% (-0.074 mm), breaking the tightly intergrowth structure of copper-zinc intergrowths and achieving a copper-zinc monomer liberation degree ≥92%. Simultaneously, it couples this with microbubble flotation technology with a froth diameter of 30~80 μm, solving the problems of poor floatability and low collection probability caused by excessively fine particles. Controlling the froth particle size ensures a better match between the froth and fine particles, increasing the collision probability. During flotation, chalcopyrite with copper collector adsorbed on its surface floats with the microbubbles, forming a copper concentrate froth product; sphalerite, inhibited by SO2, remains in the slurry, forming a zinc-enriched tailings slurry, achieving efficient separation of copper and zinc. Compared with traditional flotation, microbubble flotation technology (foam diameter 30~80 μm) provides more sufficient contact with fine-grained zinc minerals, resulting in a higher collision probability and more complete copper-zinc liberation, avoiding the loss of fine-grained zinc minerals and significantly improving zinc recovery.

[0012] Furthermore, this invention precisely controls the temperature of the zinc inhibitor mixing process with the finely ground slurry to 40-50°C. This temperature range is the optimal range for SO2 to form a sulfite system in the slurry and selectively inhibit sphalerite. If the temperature is too low, the inhibition reaction rate is slow and the effect is poor; if the temperature is too high, SO2 will escape, reducing the inhibition efficiency. After SO2 dissolves in the slurry, it forms sulfite (H2SO3). Sulfite ions can selectively adsorb onto the surface of sphalerite, forming a hydrophilic layer, significantly reducing its floatability and achieving highly efficient inhibition of zinc minerals. At the same time, the introduction of SO2 can maintain the pH value of the slurry at 5.5-6.8 during the reaction process, eliminating the need for additional acid-base adjusters and further reducing costs.

[0013] This invention organically couples "ultrafine grinding dissociation (-0.074 mm accounting for 92%~95%) - precise temperature control - SO2 in-situ suppression - microbubble flotation separation (foam diameter is 30~80 μm)" to form a new technology system for a dedicated separation process for finely embedded copper concentrate (rather than smelting slag or electrostatic ash).

[0014] In this invention, the tailings obtained from copper flotation separation are defined as zinc concentrate. The grade of zinc concentrate is ≥45%.

[0015] As a preferred embodiment, the grinding process employs a combined system of a vertical stirred mill and a hydrocyclone.

[0016] As a preferred embodiment, the sulfur dioxide generated during the copper smelting process is added by using a microporous aerator to uniformly disperse the sulfur dioxide in the slurry.

[0017] As a preferred embodiment, the zinc inhibitor is waste sulfur dioxide generated during the copper smelting process. By introducing waste sulfur dioxide from the copper smelting process, the limitations of purchasing chemical zinc inhibitors in existing technologies are overcome, enabling in-situ resource utilization of smelting waste. This is significantly different from existing recycling methods that employ plasma reduction, acid-base leaching, and other processes.

[0018] As a preferred embodiment, the heat source for mixing the zinc inhibitor with the finely ground slurry comes from the waste heat of steam from the copper smelting system.

[0019] This invention is the first to directly use waste SO2 from copper smelting flue gas as a zinc inhibitor, simultaneously coupling it with waste heat from smelting steam as a heat source for mixing the zinc inhibitor with finely ground ore slurry, thus constructing an integrated process of "treating waste with waste and utilizing waste heat." This breakthrough overcomes the limitations of existing technologies that rely on purchasing chemical zinc inhibitors and external heat sources, and also differs from the traditional use of SO2 for flue gas desulfurization or sulfuric acid production. It reduces reagent and energy costs, decreases SO2 emissions and waste heat, achieving both environmental and economic benefits. This approach is completely different from existing waste-to-waste processes such as the "co-treatment of high-arsenic alkaline wastewater and copper smelting electrostatic ash."

[0020] As a preferred embodiment, the amount of zinc inhibitor used is 200~600 g / t on a dry basis of finely ground slurry.

[0021] As a preferred embodiment, in step (2), the method further includes: first heating the finely ground slurry to 40-50°C, then adding a zinc inhibitor to the heated slurry and stirring for 15-25 minutes, followed by adding a copper collector and stirring for 8-15 minutes. Heating the slurry before adding the zinc inhibitor allows for the formation of sulfite, which selectively adsorbs sulfite ions onto the surface of sphalerite. After adding the copper collector and stirring for 8-15 minutes, the copper collector molecules selectively adsorb onto the surface of chalcopyrite, forming a hydrophobic film. This significantly improves the floatability of the copper minerals, creating a distinct floatability difference with the suppressed zinc minerals, thus ensuring subsequent flotation separation.

[0022] As a preferred embodiment, the stirring speed is 180~250 r / min.

[0023] As a preferred embodiment, the copper collector is selected from at least one of ethyl thiocyanate, ethyl thiocyanate and black powder.

[0024] As a preferred embodiment, the copper collector is a combination of ethyl thiocyanate, ethyl thiocyanate and black powder in a mass ratio of (4~6):(2~3):(1~2).

[0025] As a preferred embodiment, the total amount of copper collector used, based on the dry basis of finely ground slurry, is 30-80 g / t, more preferably 40-80 g / t.

[0026] As a preferred embodiment, the zinc content in the copper concentrate is 2-3 wt%.

[0027] As a preferred embodiment, the aeration rate of the microbubble flotation is 0.6~1.2 m³ / (m²·min).

[0028] As a preferred embodiment, the mass concentration of the finely ground slurry is 30% to 35%.

[0029] As a preferred embodiment, the copper flotation separation adopts a flotation process of one roughing, two cleaning, and one scavenging stage. No additional copper collector or zinc inhibitor is required during the cleaning stage, but 2-20 g / t of copper collector is added during the scavenging stage.

[0030] As a preferred embodiment, in step (3), the method further includes sequentially concentrating, filtering and drying the zinc-enriched tailings slurry obtained from copper flotation to obtain zinc concentrate.

[0031] As a preferred embodiment, in step (3), the method further includes concentrating, filtering and drying the obtained copper foam to obtain copper concentrate.

[0032] Compared with the prior art, the present invention has at least the following advantages:

[0033] (1) This invention achieves deep dissociation of copper and zinc in the intergrown body through ultrafine grinding, and then uses SO2 suppression under precise temperature control of 40~50℃ as the core, combined with microbubble capture by microbubble flotation, which solves the industry problems of insufficient dissociation, poor suppression effect and loss of fine zinc particles in traditional processes. Compared with existing complex processes such as plasma blowing and continuous leaching, the process is simpler and more adaptable.

[0034] (2) The process flow of this invention can be directly embedded into the beneficiation-smelting connection link of existing copper smelters. Only an ultrafine grinding and classification system, SO2 collection and pressure stabilization device and microbubble flotation column need to be added, without large-scale modification of existing production lines. At the same time, the process parameters are controllable and the reaction conditions are mild, which is suitable for continuous industrial production. It solves the pain points of existing new technologies (such as two-stage leaching and extraction separation) being difficult to apply industrially and requiring large equipment investment. Moreover, it focuses on zinc recovery in the copper concentrate pretreatment stage, filling the application gap of existing technologies. It has broad industrial application prospects, the process is compatible with existing copper smelter production lines, the operation is simple and the parameters are controllable, no high temperature and high pressure equipment is required, and it is suitable for large-scale industrial promotion. It can promote the upgrading of the comprehensive utilization level of resources in the copper smelting industry, which is different from the application limitations of existing complex processes.

[0035] (3) The resource recovery efficiency has been greatly improved, increasing the zinc recovery rate in copper concentrate from 17% in the traditional process to more than 85%, with copper concentrate grade ≥28% and zinc concentrate grade ≥45%, achieving efficient enrichment of low-content zinc resources, which is far higher than the efficiency level of zinc recovery from existing copper smelting by-products.

[0036] (4) Significant economic benefits: For a smelter that processes 1 million tons of copper concentrate per year, 20,000 to 30,000 tons of zinc concentrate can be recovered, generating an additional market value of 500 to 600 million yuan; at the same time, the cost of purchasing zinc inhibitors (calculated at 100 g / t based on the existing process, the annual cost of reagents is saved by more than 10 million yuan) and external heat sources is eliminated, resulting in an annual cost saving of more than 20 million yuan in production costs, with economic benefits far exceeding those of the existing recovery process.

[0037] (5) It has outstanding environmental benefits, realizing the in-situ resource utilization of SO2 waste from copper smelting, reducing SO2 desulfurization costs and emissions; the recovery and utilization of steam waste heat reduces the enterprise's energy consumption and carbon emissions, with no secondary pollution, which is in line with the concept of green metallurgy and is superior to the drawbacks of the existing wet leaching process that generates a large amount of acidic wastewater. Attached Figure Description

[0038] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0039] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0040] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by those skilled in the art without creative effort are still within the scope of protection of the present invention.

[0041] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0042] In this invention, room temperature refers to 25±2℃.

[0043] Example 1

[0044] The specific steps for processing copper concentrate containing 2.0 wt% zinc from a copper smelter, with an annual processing capacity of 1 million tons, are as follows:

[0045] (1) Raw material preparation: Add water to copper concentrate to prepare a slurry with a mass concentration of 30%, and stir evenly;

[0046] (2) Ultrafine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain a finely ground slurry; the -0.074 mm particles in the finely ground slurry account for 92% of the total solid particles, and the dissociation degree of copper and zinc monomers is 92%;

[0047] (3) Waste heat temperature control and SO2 in situ suppression: The fine-ground slurry is heated to 40°C using the waste heat of steam. The waste gas SO2 generated during the copper smelting process is introduced through a microporous aerator at a dosage of 200 g / t (based on the dry basis of the fine-ground slurry). The stirring speed is 180 r / min, the reaction time is 15 min, and the slurry pH is 6.8.

[0048] (4) Addition of copper collector: Add ethyl thiocyanate at a dosage of 30 g / t (based on dry fine-ground slurry) and stir for 8 min;

[0049] (5) Microbubble flotation separation: The microbubble is fed into a microbubble flotation column with a microbubble diameter of 80 μm and an aeration rate of 0.6 m³ / (m²·min). The process of one roughing, two cleaning and one scavenging is adopted (the microbubble diameters of roughing, cleaning and scavenging are the same). Blank cleaning is used without additional reagents. Scavenging is supplemented with 12 g / t of ethyl thiocyanate (based on the dry basis of finely ground slurry) to obtain copper concentrate.

[0050] (6) Preparation of copper and zinc concentrates: The zinc-enriched tailings slurry obtained by copper flotation separation is concentrated, filtered and dried to obtain zinc concentrate, and the copper froth obtained by copper flotation separation is concentrated, filtered and dried to obtain copper concentrate.

[0051] Test results: Zinc recovery rate 85.0%, copper concentrate grade 28.5%, and zinc concentrate grade 45.2%.

[0052] Example 2

[0053] The specific steps for processing copper concentrate containing 2.5 wt% zinc from a copper smelter, with an annual processing capacity of 1.2 million tons, are as follows:

[0054] (1) Raw material slurry preparation: Add water to copper concentrate to prepare a slurry with a mass concentration of 33%, and stir evenly;

[0055] (2) Ultrafine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 93% of the total solid particles, and the copper-zinc monomer dissociation degree is 94%;

[0056] (3) Waste heat temperature control and SO2 in situ suppression: The fine-ground slurry is heated to 45°C using the waste heat of steam. The waste gas SO2 generated during the copper smelting process is introduced through a microporous aerator at a dosage of 400 g / t (based on the dry basis of the fine-ground slurry). The stirring speed is 220 r / min, the reaction time is 20 min, and the slurry pH is 6.2.

[0057] (4) Addition of copper collector: Add compound copper collector (ethyl thiocyanate: ethyl thiocyanate: black powder = 5:2:1), dosage 40g / t (based on dry fine-ground slurry), stir and mix for 12 min;

[0058] (5) Microbubble flotation separation: The microbubble is fed into a microbubble flotation column with a microbubble diameter of 50 μm and an aeration rate of 0.9 m³ / (m²·min). The process of one roughing, two cleaning and one scavenging is adopted (the microbubble diameters of roughing, cleaning and scavenging are the same). Blank cleaning is used without additional reagents. Scavenging is supplemented with compound copper collector (ethyl thiocyanate: ethyl thiocyanate: black reagent = 5:2:1) 16 g / t (based on dry basis of finely ground slurry).

[0059] (6) Preparation of copper and zinc concentrates: The zinc-enriched tailings slurry obtained by copper flotation separation is concentrated, filtered and dried to obtain zinc concentrate, and the copper froth obtained by copper flotation separation is concentrated, filtered and dried to obtain copper concentrate.

[0060] Test results: Zinc recovery rate 88.5%, copper concentrate grade 29.2%, and zinc concentrate grade 46.8%.

[0061] Example 3

[0062] The specific steps for processing copper concentrate containing 3.0 wt% zinc from a copper smelter, with an annual processing capacity of 1.5 million tons, are as follows:

[0063] (1) Raw material slurry preparation: Add water to copper concentrate to prepare a slurry with a mass concentration of 35%, and stir evenly;

[0064] (2) Ultrafine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 95% of the total solid particles, and the dissociation degree of copper and zinc monomers is 95%;

[0065] (3) Waste heat temperature control and SO2 in situ inhibition: The fine-ground slurry is heated to 50°C using waste heat of steam, and waste SO2 is introduced using a microporous aerator at a dosage of 600 g / t (based on the dry basis of the fine-ground slurry). The stirring speed is 250 r / min, the reaction time is 25 min, and the slurry pH is 5.5.

[0066] (4) Addition of copper collector: Add compound copper collector (ethyl thiocyanate: Z200: black powder = 6:3:2), dosage 60 g / t (based on dry fine-ground slurry), stir and mix for 15 min;

[0067] (5) Microbubble flotation separation: feed into a microbubble flotation column with a microbubble diameter of 30 μm and an aeration rate of 1.2 m³ / (m²·min). The process is one roughing, two cleaning, and one scavenging (the microbubble diameters of the roughing, cleaning, and scavenging are the same). Blank cleaning is used without additional reagents. Scavenging is supplemented with 20 g / t of compound copper collector (based on the dry basis of finely ground slurry).

[0068] (6) Preparation of copper and zinc concentrates: The zinc-enriched tailings slurry obtained by copper flotation separation is concentrated, filtered and dried to obtain zinc concentrate, and the copper froth obtained by copper flotation separation is concentrated, filtered and dried to obtain copper concentrate.

[0069] Test results: Zinc recovery rate 90.2%, copper concentrate grade 29.8%, and zinc concentrate grade 47.5%.

[0070] Comparative Example 1

[0071] The copper concentrate is the same as in Example 1.

[0072] Step (1) is the same as in Example 1;

[0073] Step (2): Fine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 77% of the total solid particles, and the degree of dissociation of copper and zinc monomers is 75%;

[0074] Step (3): Add ethyl thiocyanate at a dosage of 30 g / t (based on the dry weight of finely ground slurry) and stir for 8 min;

[0075] Step (4): Microbubble flotation separation: feed into a microbubble flotation column with a microbubble diameter of 80 μm and an aeration rate of 0.6 m³ / (m²·min). Use a "one roughing, two cleaning, one scavenging" process (the microbubble diameters of the roughing, cleaning, and scavenging are the same). Use blank cleaning without additional reagents. Add 12 g / t of ethyl thiocyanate (based on the dry basis of finely ground slurry) to the scavenging process to obtain copper concentrate.

[0076] Step (5): Preparation of copper and zinc concentrates: The zinc-enriched tailings slurry obtained from copper flotation is concentrated, filtered and dried to obtain zinc concentrate. The copper froth obtained from copper flotation is concentrated, filtered and dried to obtain copper concentrate.

[0077] Test results: Zinc recovery rate 26.0%, copper concentrate grade 18.5%, zinc concentrate grade 28.0%.

[0078] Comparative Example 2

[0079] The copper concentrate is the same as in Example 1.

[0080] Step (1) is the same as in Example 1;

[0081] Step (2): Fine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 77% of the total solid particles, and the degree of dissociation of copper and zinc monomers is 75%;

[0082] Step (3): SO2 in situ suppression: without heating the slurry (the slurry temperature is room temperature), use a microporous aerator to introduce the waste gas SO2 generated in the copper smelting process, the dosage is 200 g / t (based on the dry basis of finely ground slurry), the stirring speed is 180 r / min, the reaction is 15 min, and the slurry pH is 7.2;

[0083] Steps (4), (5) and (6) are the same as in Example 1.

[0084] Test results: Zinc recovery rate 51.0%, copper concentrate grade 22.3%, and zinc concentrate grade 35.1%.

[0085] Comparative Example 3

[0086] The copper concentrate is the same as in Example 1.

[0087] Step (1) is the same as in Example 1;

[0088] Step (2): Fine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 77% of the total solid particles, and the degree of dissociation of copper and zinc monomers is 75%;

[0089] Step (3): Waste heat temperature control: Use the waste heat of steam to heat the finely ground slurry to 40°C, and the pH of the slurry is 7.0;

[0090] Steps (4), (5) and (6) are the same as in Example 1.

[0091] Test results: Zinc recovery rate 35.0%, copper concentrate grade 19.7%, and zinc concentrate grade 30.5%.

[0092] Comparative Example 4

[0093] The copper concentrate is the same as in Example 1.

[0094] Step (1) is the same as in Example 1;

[0095] Step (2): Fine grinding and dissociation: The ore is fed into a vertical stirred mill + hydrocyclone system for grinding to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 77% of the total solid particles, and the degree of dissociation of copper and zinc monomers is 75%;

[0096] Steps (3), (4), (5) and (6) are the same as in Example 1.

[0097] Test results: Zinc recovery rate 76.0%, copper concentrate grade 24.8%, and zinc concentrate grade 40.2%.

[0098] Comparative Example 5

[0099] The copper concentrate is the same as in Example 1.

[0100] This comparative example was carried out using a method similar to that of Example 1, except that in step (5), the diameter of the microbubbles for coarse selection, fine selection and sweeping selection was adjusted to 100 μm and the aeration rate was 0.6 m³ / (m²·min).

[0101] Test results: Zinc recovery rate 68.5%, copper concentrate grade 24.2%, zinc concentrate grade 38.6%. (The foam diameter exceeded the scope of this invention, reducing the probability of collision between microbubbles and fine-grained minerals, resulting in a decreased collection effect. Consequently, both the zinc recovery rate and concentrate grade were significantly lower than in Example 1.)

[0102] Comparative Example 6

[0103] The copper concentrate is the same as in Example 1.

[0104] This comparative example was carried out using a method similar to that of Example 1. The difference was that in step (3), sulfur dioxide was not used as a zinc inhibitor, the slurry was not heated (the slurry temperature was room temperature), and only the traditional zinc inhibitors zinc sulfate and sodium sulfite (mass ratio 1:1) were added, with a total dosage of 600 g / t (based on the dry basis of finely ground slurry). The pH of the slurry was adjusted to 7.0-7.5 with lime, and the reaction was stirred for 15 min. The remaining steps were the same as in Example 1.

[0105] Test results: Zinc recovery rate 62.5%, copper concentrate grade 22.8%, and zinc concentrate grade 36.3%.

[0106] The results showed that, at the same grinding fineness, the inhibitory effect of traditional zinc inhibitors on zinc minerals was significantly weaker than that of the sulfur dioxide combined with steam waste heat zinc inhibitor of the present invention. The zinc recovery rate was significantly lower, and the grades of both copper and zinc concentrates were also lower than those in Example 1. Furthermore, traditional zinc inhibitors require additional external purchase and must be used in conjunction with pH adjusters, resulting in higher reagent costs and failing to achieve in-situ resource utilization of smelting waste.

[0107] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for recovering associated zinc from copper concentrate during copper smelting, characterized by: steps include: (1) Copper concentrate is slurried and ground to obtain fine grinding slurry; the -0.074 mm particles in the fine grinding slurry account for 92~95% of the total solid particles; (2) The finely ground slurry is mixed with a copper collector and a zinc inhibitor; the zinc inhibitor contains sulfur dioxide, and the temperature of the mixing process between the zinc inhibitor and the finely ground slurry is 40~50℃; (3) The copper slurry from step (2) is separated by microbubble flotation to obtain copper concentrate and zinc concentrate; the diameter of the microbubble flotation froth is 30~80 μm.

2. The method for recovering associated zinc from copper concentrate during copper smelting according to claim 1, characterized in that: The zinc inhibitor is waste sulfur dioxide generated during the copper smelting process.

3. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: The heat source for mixing the zinc inhibitor with the finely ground slurry comes from the waste heat of steam from the copper smelting system.

4. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: The amount of zinc inhibitor used is 200~600g / t based on the dry basis of finely ground slurry.

5. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: In step (2), the method further includes: first heating the finely ground slurry to 40~50℃, then adding a zinc inhibitor to the heated finely ground slurry and stirring for 15~25 min, and then adding a copper collector and stirring for 8~15 min.

6. The method for recovering associated zinc from copper concentrate during copper smelting according to claim 5, characterized in that: The stirring speed is 180~250 r / min.

7. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: The copper collector is selected from at least one of ethyl thiocyanate, ethyl thiocyanate and black powder.

8. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: The zinc content in the copper concentrate is 2-3 wt%.

9. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: The aeration rate for the microbubble flotation is 0.6~1.2 m³ / (m²·min).

10. A method for recovering associated zinc from copper concentrate during copper smelting according to claim 1 or 2, characterized in that: The mass concentration of the finely ground slurry is 30%~35%.

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