Method for applying mine acid wastewater to copper-sulfur ore separation

Abstract

The invention discloses a method for applying mine acid wastewater to copper-sulfur ore separation, and relates to the technical field of ore separation. According to the method, a certain amount of mine acid waste water is added in ore grinding operation and ground material size mixing, and iron and calcium ions in the mine acid waste water are fully utilized to selectively inhibit pyrite; through the technical scheme of calcium hypochlorite oxidation modification-ethyl thionocarbamate powerful collection-sodium sulfite coupling regulation under low alkalinity, after the copper and sulfur separation process of primary roughing, secondary scavenging, tertiary concentration and middling sequential returning is adopted, source resource treatment of the mine acid wastewater and efficient and green separation of the copper and sulfur ore are achieved. Results show that selective inhibition of the pyrite is achieved through introduction of the mine acid wastewater and reasonable addition of the agents, efficient collection of the collecting agent on the chalcopyrite is enhanced, and the recovery rate of the copper concentrate is increased. Compared with a traditional lime high alkali-xanthate separation process, the copper recovery rate is increased by 2% or above.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, in particular to a method for applying acid mine wastewater to copper-sulfur ore separation. Background Art

[0002] my country's copper ore deposits encompass a wide range of industrial types, with copper sulfide ores being the primary type. Copper-sulfide ore is the most common type of copper sulfide ore and is widely distributed. Flotation is the most commonly used separation method for copper-sulfide ores, and copper-sulfur separation is a key issue in the separation of these ores. Currently, the primary method for separating copper-sulfur ore in production is the lime-based high-alkali process. However, the use of large amounts of lime presents drawbacks such as scaling, pipe clogging, large fluctuations in added lime levels, and environmental pollution from mine wastewater. Furthermore, this process can inhibit the flotation of some copper minerals, impacting the recovery of copper concentrate. Highly alkaline conditions also contribute to the loss of associated elements such as molybdenum, gold, and silver. Therefore, the development of low-alkali processes that require no or minimal lime is the overall trend for green and efficient separation of copper-sulfur ore.

[0003] During mining, transportation, and storage, copper-sulfur ore, exposed to air, water, and microorganisms, undergoes a series of physical, chemical, and biochemical reactions, including weathering, leaching, oxidation, and hydrolysis. This gradually generates acid mine drainage (AMD), which contains heavy metal ions such as sulfuric acid, iron, and copper. Government and industry leaders recognize AMD as a primary environmental issue facing the mining industry today. Furthermore, copper-sulfur mines are often located in water-scarce areas, necessitating the comprehensive utilization of acid mine drainage in mineral processing operations. The treatment of AMD has long been a focus of environmental research both domestically and internationally. Remediation methods such as neutralization, sulfide precipitation, adsorption, ion exchange, and constructed wetland digestion have been applied in mining areas. These remediation methods primarily focus on removing the acidity, metal ions, and sulfate content of AMD. However, they require a continuous supply of chemicals and energy, as well as long-term monitoring of the affected ecosystems. Therefore, achieving source control or on-site resource utilization of AMD is of great practical significance.

[0004] Research on AMD in the flotation field has been reported. Patent application number 2017112091537, "A Method for Beneficiating Highly Weathered, Highly Muddy, Sulfur-Oxygen Mixed Copper Ore," discloses adding acidic mine wastewater during copper scavenging and separation to inhibit the adsorption and flotation of ore mud on the mineral surface, thereby optimizing the flotation and mineralization environment for copper minerals. However, the amount of acidic mine wastewater added in this patent is relatively small (no more than 200 mL / ton of raw ore), which is not conducive to its efficient utilization. Patent application number 2016102526275, "A Method for Recovering Valuable Components from Sulfur-Oxygen Mixed Copper-Lead Ore," discloses leaching copper from lead concentrate with copper-containing acidic wastewater. After solid-liquid separation, sodium sulfide is added to obtain copper concentrate. However, the applicability of this method to acidic wastewater with complex components remains to be verified, as other ions (iron, lead, zinc, etc.) in the acidic wastewater can affect the quality of the copper concentrate. Patent application number 202210079879.8, "A High-Sulfur Copper-Sulfur Ore Beneficiation Auxiliary Agent and Beneficiation Method," discloses a technology for sulfur separation using acidic wastewater activation. However, this method is limited to the separation of iron sulfide from tailings after copper selection under high-alkali conditions. Furthermore, to improve the flotation environment for copper and sulfur separation, some mineral processing researchers have conducted extensive research on copper-sulfur separation inhibitors. However, reports on highly effective inhibitors for copper-sulfur separation in AMD systems are limited.

[0005] In summary, the existing technology needs to be improved. The research and development of AMD source disposal or on-site resource utilization technology and lime-free low-alkalinity copper-sulfur ore beneficiation technology will be one of the important ways to achieve efficient and clean production of such ore resources. In response to the above problems, the inventors proposed a method for applying mine acidic wastewater to copper-sulfur ore sorting to solve the above problems. Summary of the Invention

[0006] In order to solve the problem that the existing process needs to be improved, the research and development of AMD source disposal or on-site resource utilization technology and lime-free low-alkalinity copper-sulfur ore beneficiation technology will be one of the important ways to achieve efficient and clean production of such ore resources; the purpose of the present invention is to provide a method for applying mine acidic wastewater to copper-sulfur ore sorting.

[0007] To solve the above technical problems, the present invention adopts the following technical solution: a method for applying acid mine wastewater to copper-sulfur ore separation, comprising the following steps:

[0008] S1. Add a certain mass ratio of acid mine wastewater (AMD: industrial water mass ratio is 1-3:1) to the raw ore grinding operation, and grind the ore until the content of -74μm ore powder accounts for 75-85wt%; add acid mine wastewater and industrial water (mass ratio is 1-3:1) to the material discharged from the mill, and slurry is adjusted to a slurry concentration of 25-35wt%;

[0009] S2. Add sodium carbonate to the slurry in step S1 to adjust the slurry pH to 7.5-8.5, and stir for 2-4 minutes; add 500-900 g / t of calcium hypochlorite, and stir for 4-6 minutes; add 10-20 g / t of ethylthiocarbamate, and stir for 2-4 minutes; add 300-500 g / t of sodium sulfite, and stir for 2-4 minutes; add 8-14 g / t of 2# oil, and stir for 2-4 minutes to perform copper-sulfur separation and roughing to obtain foam and underflow;

[0010] S3, adding 250-450 g / t of calcium hypochlorite to the underflow obtained in step S2, stirring for 4-6 min; adding 5-10 g / t of ethylthiocarbamate, stirring for 2-4 min; adding 150-250 g / t of sodium sulfite, stirring for 2-4 min; adding 4-7 g / t of 2# oil, stirring for 2-4 min, and performing copper-sulfur separation and scavenging I to obtain foam and underflow;

[0011] S4. Add 125-225 g / t of calcium hypochlorite to the underflow obtained in step S3, and stir for 4-6 min; add 2.5-5 g / t of ethylthiocarbamate, and stir for 2-4 min; add 75-125 g / t of sodium sulfite, and stir for 2-4 min; add 2-3.5 g / t of 2# oil, and stir for 2-4 min, and perform copper-sulfur separation and scavenging II to obtain foam and underflow, wherein the copper-sulfur separation and scavenging II foam is returned to the copper-sulfur separation and scavenging I operation;

[0012] S5. Sodium carbonate is added to the foam obtained in step S2 in sequence to adjust the pulp pH to 7.5-8.5, and the mixture is stirred for 2-4 min. Calcium hypochlorite 200-400 g / t is stirred for 4-6 min, and sodium sulfite 100-200 g / t is stirred for 2-4 min. Copper-sulfur separation and selection I is performed to obtain foam and underflow; wherein the copper-sulfur separation and selection I underflow and the copper-sulfur separation scavenging selection I foam are returned to the copper-sulfur separation roughing operation together;

[0013] S6. Sodium carbonate is sequentially added to the foam obtained in step S5 to adjust the pulp pH to 7.5-8.5, and the mixture is stirred for 2-4 min. 100-200 g / t of calcium hypochlorite is stirred for 4-6 min, and 50-100 g / t of sodium sulfite is stirred for 2-4 min. Copper-sulfur separation and selection II is performed to obtain foam and underflow; wherein the underflow of copper-sulfur separation and selection II is returned to the copper-sulfur separation and selection I operation;

[0014] S7, adding sodium carbonate to the foam obtained in step S6 in sequence to adjust the slurry pH to 7.5-8.5, stirring for 2-4 minutes, and adding 4-8 g / t of ethylthiocarbamate, stirring for 2-4 minutes, and performing copper-sulfur separation and concentration III to obtain foam (i.e., copper concentrate) and underflow; wherein the copper-sulfur separation and concentration III underflow is returned to the copper-sulfur separation and concentration II operation;

[0015] Furthermore, the characteristics and main components of the acid mine drainage AMD are as follows: pH = 2-4, sulfate ion 1000-130000 mg·L -1 , iron ion 200~1000mg·L -1 , copper ion 100~250mg·L -1 , calcium ion 300~600mg·L -1 .

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Applying natural acid mine drainage (AMD) to grinding and copper-sulfur separation and flotation operations not only realizes the resource utilization of acid wastewater, saves groundwater resources, and alleviates the harm of AMD to the surrounding ecological environment, but also utilizes calcium and iron ions in AMD to selectively inhibit pyrite. This invention has significant advantages of environmental protection and energy saving.

[0018] 2. Based on the difference in surface oxidation resistance between pyrite and chalcopyrite, the present invention utilizes the oxidizing effect of calcium hypochlorite to deeply oxidize the surface of pyrite, promoting the capping of strongly hydrophilic species (iron hydroxyl, calcium hydroxyl, etc.) on the mineral surface, thereby improving the hydrophilicity of the pyrite surface. Calcium hypochlorite has little effect on the floatability of chalcopyrite. Therefore, the selective oxidation modification effect of calcium hypochlorite enhances the flotation separation of chalcopyrite and pyrite.

[0019] 3. Based on the stronger affinity of ethylthiocarbamate collector for copper than iron, the ethylthiocarbamate used in the present invention can strongly chelate with the copper active sites on the surface of chalcopyrite, causing the mineral surface to float hydrophobically. However, ethylthiocarbamate has a weaker collection ability for pyrite, thereby improving the separation index of chalcopyrite.

[0020] 4. Compared with chalcopyrite, the redox potential of the pyrite surface after the action of calcium hypochlorite and ethylthiocarbamate is higher, and sodium sulfite easily interacts with the pyrite surface. The present invention effectively desorbs ethylthiocarbamate from the pyrite surface through the coupling regulation of sodium sulfite. In addition, sodium sulfite easily adsorbs on the pyrite surface, greatly increasing the hydrophilicity of the mineral surface and further improving the separation effect of copper and sulfur.

[0021] 5. The present invention realizes efficient separation of copper-sulfur ore at low alkalinity (pH=7.5-8.5) through the combined action of AMD, calcium hypochlorite and sodium sulfite. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a process flow chart of a method for separating copper-sulfur ores using acidic mine wastewater according to the present invention;

[0024] Figure 2 The figure is a flow chart of the flotation separation test of artificial mixed ore in different solution systems of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] like Figure 1-2 As shown, the present invention provides:

[0027] Example 1

[0028] A copper-sulfur ore from Yunnan contains 0.45% copper, 14.40% sulfur, and 15.65% iron. The primary metallic minerals in the ore are chalcopyrite and pyrite, with minor and trace minerals such as bornite and chalcocite. Gangue minerals are primarily quartz and calcite, with minor amounts of pyroxene and chlorite. Analysis of the copper phases in the ore indicates that primary copper minerals account for 95% of the total copper phase, with chalcopyrite being the predominant component. The characteristics and main components of AMD are as follows: pH = 3.5, sulfate ion 8340 mg·L -1 、Iron ion 318mg·L -1 、Copper ion 138mg·L -1 , calcium ion 415mg·L -1 .

[0029] The specific beneficiation steps are as follows:

[0030] S1. Add a certain mass ratio of acid mine wastewater (AMD: industrial water mass ratio is 1:1) to the raw ore grinding operation, and grind the ore to a content of 75wt% of -74μm ore powder; add acid mine wastewater and industrial water (mass ratio is 1:1) to the material discharged from the mill, and slurry is adjusted to a slurry concentration of 25wt%;

[0031] S2. Add sodium carbonate to the slurry in step S1 to adjust the slurry pH to 7.5, and stir for 2 minutes; add 500 g / t of calcium hypochlorite, stir for 4 minutes; add 10 g / t of ethylthiocarbamate, stir for 2 minutes; add 300 g / t of sodium sulfite, stir for 2 minutes; add 8 g / t of 2# oil, stir for 2 minutes, and perform copper-sulfur separation and roughing to obtain foam and underflow;

[0032] S3, adding 250g / t of calcium hypochlorite to the underflow obtained in step S2, stirring for 4min; adding 5g / t of ethylthiocarbamate, stirring for 2min; adding 150g / t of sodium sulfite, stirring for 2min; adding 4g / t of 2# oil, stirring for 2min, and performing copper-sulfur separation and scavenging I to obtain foam and underflow;

[0033] S4. Add 125 g / t of calcium hypochlorite to the underflow obtained in step S3 and stir for 4 min; add 2.5 g / t of ethylthiocarbamate and stir for 2 min; add 75 g / t of sodium sulfite and stir for 2 min; add 2 g / t of 2# oil and stir for 2 min, and perform copper-sulfur separation and scavenging II to obtain foam and underflow, wherein the copper-sulfur separation and scavenging II foam is returned to the copper-sulfur separation and scavenging I operation;

[0034] S5. Sodium carbonate is added to the foam obtained in step S2 in sequence to adjust the pulp pH to 7.5, and the mixture is stirred for 2 minutes. 200 g / t of calcium hypochlorite is stirred for 4 minutes, and 100 g / t of sodium sulfite is stirred for 2 minutes to perform copper-sulfur separation and selection I to obtain foam and underflow; wherein the copper-sulfur separation and selection I underflow and the copper-sulfur separation scavenging selection I foam are returned to the copper-sulfur separation roughing operation together;

[0035] S6. Sodium carbonate was added to the foam obtained in step S5 in sequence to adjust the pulp pH to 7.5, and the mixture was stirred for 2 min. 100 g / t of calcium hypochlorite was stirred for 4 min, and 50 g / t of sodium sulfite was stirred for 2 min. Copper-sulfur separation and selection II was performed to obtain foam and underflow; wherein the underflow of copper-sulfur separation and selection II was returned to the copper-sulfur separation and selection I operation;

[0036] S7. Sodium carbonate was added to the foam obtained in step S6 to adjust the slurry pH to 7.5, and the mixture was stirred for 2 minutes. Ethylthiocarbamate (4 g / t) was added and stirred for 2 minutes to perform copper-sulfur separation and concentration III to obtain foam (i.e., copper concentrate) and underflow; wherein the underflow of copper-sulfur separation and concentration III was returned to the copper-sulfur separation and concentration II operation;

[0037] Experimental results: When the addition amount of acid mine drainage (AMD) was 50% of the total water used in grinding operation and copper flotation separation operation, the copper concentrate grade was 20.34% and the copper recovery rate was 91.65%.

[0038] Example 2

[0039] A copper-sulfur ore in Yunnan contains 0.62% copper, 21.85% sulfur, and 23.42% iron. The primary metallic minerals in the ore are chalcopyrite and pyrite, with minor and trace minerals such as bornite and azurite. Gangue minerals are primarily quartz and calcite. Analysis of the copper phases in the ore indicates that primary copper minerals account for 93% of the total copper phase, with chalcopyrite being the predominant component. The characteristics and main components of AMD are as follows: pH = 2.8, sulfate ion 9600 mg·L -1 、Iron ion 456mg·L -1 、Copper ion 218mg·L -1 , calcium ion 435mg·L -1 .

[0040] The specific beneficiation steps are as follows:

[0041] S1. Add a certain mass ratio of acid mine wastewater (AMD: industrial water mass ratio is 2:1) to the raw ore grinding operation, and grind the ore to a content of 80wt% of -74μm ore powder; add acid mine wastewater and industrial water (mass ratio is 2:1) to the material discharged from the mill, and slurry is adjusted to a slurry concentration of 30wt%;

[0042] S2. Add sodium carbonate to the slurry in step S1 to adjust the slurry pH to 8.0, and stir for 3 minutes; add 700 g / t of calcium hypochlorite, stir for 5 minutes; add 20 g / t of ethylthiocarbamate, stir for 3 minutes; add 400 g / t of sodium sulfite, stir for 3 minutes; add 12 g / t of 2# oil, stir for 3 minutes, and perform copper-sulfur separation and roughing to obtain foam and underflow;

[0043] S3, adding 350g / t of calcium hypochlorite to the underflow obtained in step S2, stirring for 5min; adding 10g / t of ethylthiocarbamate, stirring for 3min; adding 200g / t of sodium sulfite, stirring for 3min; adding 6g / t of 2# oil, stirring for 3min, and performing copper-sulfur separation and scavenging I to obtain foam and underflow;

[0044] S4. Add 175 g / t of calcium hypochlorite to the underflow obtained in step S3 and stir for 5 min; add 5 g / t of ethylthiocarbamate and stir for 3 min; add 100 g / t of sodium sulfite and stir for 3 min; add 3 g / t of 2# oil and stir for 3 min, and perform copper-sulfur separation and scavenging II to obtain foam and underflow, wherein the copper-sulfur separation and scavenging II foam is returned to the copper-sulfur separation and scavenging I operation;

[0045] S5. Sodium carbonate is added to the foam obtained in step S2 in sequence to adjust the pulp pH to 8.0, and the mixture is stirred for 3 minutes. 300 g / t of calcium hypochlorite is stirred for 5 minutes, and 150 g / t of sodium sulfite is stirred for 3 minutes to perform copper-sulfur separation and selection I to obtain foam and underflow; wherein the copper-sulfur separation and selection I underflow and the copper-sulfur separation scavenging and selection I foam are returned to the copper-sulfur separation roughing operation together;

[0046] S6. Sodium carbonate is added to the foam obtained in step S5 in sequence to adjust the pulp pH to 8.0, and the mixture is stirred for 3 minutes. 150 g / t of calcium hypochlorite is stirred for 4 minutes, and 50 g / t of sodium sulfite is stirred for 2 minutes to perform copper-sulfur separation and selection II to obtain foam and underflow; wherein the copper-sulfur separation and selection II underflow is returned to the copper-sulfur separation and selection I operation;

[0047] S7. Sodium carbonate was added to the foam obtained in step S6 to adjust the slurry pH to 8.0, and the mixture was stirred for 3 minutes. Ethylthiocarbamate (6 g / t) was added and stirred for 3 minutes to perform copper-sulfur separation and concentration III to obtain foam (i.e., copper concentrate) and underflow; wherein the underflow of copper-sulfur separation and concentration III was returned to the copper-sulfur separation and concentration II operation;

[0048] Experimental results: The addition amount of acid mine drainage (AMD) was 67% of the total water used in grinding operation and copper flotation separation operation, the copper concentrate grade was 21.75%, and the copper recovery rate was 93.55%.

[0049] Example 3

[0050] A copper-sulfur ore in Guangxi contains 0.92% copper, 24.26% sulfur, and 26.32% iron. The primary metallic minerals in the ore are chalcopyrite and pyrite, with minor and trace minerals such as bornite and chalcocite. Gangue minerals are primarily quartz and calcite. Analysis of the copper phases in the ore indicates that primary copper minerals account for 91% of the total copper phase, with chalcopyrite being the predominant component. The characteristics and main components of AMD are as follows: pH = 2.2, sulfate ion 12,300 mg·L -1 、Iron ion 721mg·L -1 、Copper ion 235mg·L -1 , calcium ion 528mg·L -1 .

[0051] The specific beneficiation steps are as follows:

[0052] S1. Add a certain mass ratio of acid mine wastewater (AMD: industrial water mass ratio is 3:1) to the raw ore grinding operation, and grind the ore to a content of 85wt% of -74μm ore powder; add acid mine wastewater and industrial water (mass ratio is 3:1) to the material discharged from the mill, and slurry is adjusted to a slurry concentration of 35wt%;

[0053] S2. Add sodium carbonate to the slurry in step S1 to adjust the slurry pH to 8.5, and stir for 4 minutes; add 900 g / t of calcium hypochlorite, stir for 6 minutes; add 30 g / t of ethylthiocarbamate, stir for 4 minutes; add 500 g / t of sodium sulfite, stir for 4 minutes; add 14 g / t of 2# oil, stir for 4 minutes, and perform copper-sulfur separation and roughing to obtain foam and underflow;

[0054] S3, adding 450g / t of calcium hypochlorite to the underflow obtained in step S2, stirring for 6min; adding 15g / t of ethylthiocarbamate, stirring for 4min; adding 250g / t of sodium sulfite, stirring for 4min; adding 7g / t of 2# oil, stirring for 4min, and performing copper-sulfur separation and scavenging I to obtain foam and underflow;

[0055] S4. Add 225 g / t of calcium hypochlorite to the underflow obtained in step S3 and stir for 6 min; add 7.5 g / t of ethylthiocarbamate and stir for 4 min; add 125 g / t of sodium sulfite and stir for 4 min; add 3.5 g / t of 2# oil and stir for 4 min, and perform copper-sulfur separation and scavenging II to obtain foam and underflow, wherein the copper-sulfur separation and scavenging II foam is returned to the copper-sulfur separation and scavenging I operation;

[0056] S5. Sodium carbonate is added to the foam obtained in step S2 in sequence to adjust the pulp pH to 8.5, and the mixture is stirred for 4 minutes. 400 g / t of calcium hypochlorite is stirred for 6 minutes, and 200 g / t of sodium sulfite is stirred for 4 minutes to perform copper-sulfur separation and selection I to obtain foam and underflow; wherein the copper-sulfur separation and selection I underflow and the copper-sulfur separation scavenging selection I foam are returned to the copper-sulfur separation roughing operation together;

[0057] S6. Sodium carbonate was added to the foam obtained in step S5 in sequence to adjust the pulp pH to 8.5, and the mixture was stirred for 4 min. 200 g / t of calcium hypochlorite was stirred for 6 min, and 100 g / t of sodium sulfite was stirred for 4 min. Copper-sulfur separation and selection II was performed to obtain foam and underflow; wherein the underflow of copper-sulfur separation and selection II was returned to the copper-sulfur separation and selection I operation;

[0058] S7. Sodium carbonate was added to the foam obtained in step S6 to adjust the slurry pH to 8.5, and the mixture was stirred for 4 minutes. Ethylthiocarbamate 8 g / t was added and stirred for 4 minutes to perform copper-sulfur separation and concentration III to obtain foam (i.e., copper concentrate) and underflow; wherein the copper-sulfur separation and concentration III underflow was returned to the copper-sulfur separation and concentration II operation;

[0059] Experimental results: When the addition amount of acid mine drainage (AMD) was 75% of the total water used in grinding operation and copper flotation separation operation, the copper concentrate grade was 24.86% and the copper recovery rate was 94.18%.

[0060] Comparative Example 1

[0061] The mineral processing method of this comparative example is the same as that of Example 1, except that industrial water of equal quality is used instead of acid mine wastewater, that is, no acid mine wastewater is added.

[0062] Test results: copper concentrate grade is 19.06%, copper recovery rate is 90.13%. Compared with the ore separation index in the flotation system with a mass ratio of AMD: industrial water of 1:1, the copper concentrate grade is reduced by 1.28%, and the copper recovery rate is reduced by 1.52%.

[0063] Comparative Example 2

[0064] The beneficiation method of this comparative example is the same as that of Example 2, except that industrial water of equal mass is used instead of acid mine wastewater, lime is used instead of sodium carbonate, calcium hypochlorite and sodium sulfite in an amount of 8000 g / t, and butyl xanthate is used instead of ethylthiocarbamate of equal mass, that is, the traditional high alkali process is used for separation.

[0065] Test results: copper concentrate grade 21.86%, copper recovery rate 91.15%. Compared with the test results of Example 2, the copper recovery rate decreased by 2.4%, and the copper concentrate grade did not change much.

[0066] Comparative Example 3

[0067] The mineral processing method of this comparative example is the same as that of Example 3, except that sodium sulfite is added before ethylthiocarbamate, that is, the order of addition of sodium sulfite is changed.

[0068] Test results: copper concentrate grade 23.45%, copper recovery rate 93.05%.Compared with the test results of Example 3, the copper concentrate grade decreased by 1.41%, and the copper recovery rate decreased by 1.13%.

[0069] Example 4

[0070] Artificial mixed ore (chalcopyrite:pyrite mass ratio = 1:1) was added to a hanging trough flotation machine for separation. Sodium carbonate (pH = 8.5), 100 mg / L calcium hypochlorite, 30 mg / L ethylthiocarbamate, and 6 mg / L 2# oil were added in sequence. The flotation separation effect of the artificial mixed ore in different solution systems was investigated. The characteristics and main components of the AMD were the same as those in Example 1. The results are shown in Table 1.

[0071] Table 1 Results of flotation separation tests on artificial mixed ores in different solution systems

[0072]

[0073] The results of applying acid mine wastewater to copper-sulfur ore sorting show that by adding a certain mass ratio of acid mine wastewater (AMD: industrial water mass ratio of 1 to 3:1) during ore grinding and slurry mixing operations, combined with the oxidative modification of calcium hypochlorite, the strong capture of chalcopyrite by ethylthiocarbamate, and the desorption of the collector on the surface of pyrite by sodium sulfite, a copper-sulfur separation process with one roughing, two scavenging, and three concentrating can be adopted. Compared with the traditional xanthate collector sorting process under high lime alkalinity, it can effectively improve the grade of copper concentrate and copper recovery rate, and ultimately realize the source resource utilization of acid wastewater and the efficient and green sorting of copper-sulfur ore with low alkalinity, and strengthen the flotation separation of chalcopyrite and pyrite. The results of Example 4 show that the addition of an appropriate mass ratio of acid mine wastewater can improve the separation of chalcopyrite and pyrite in artificial mixed ore, especially in improving the grade of copper concentrate. Compared with the separation indicators of the deionized water flotation system, when the mass ratio of AMD to deionized water is 1:1, the copper concentrate grade is increased by 6.27% and the copper recovery rate is increased by 9.2%, which provides important support for the application of acid mine wastewater in the flotation of copper-sulfur ores.

[0074] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.

[0075] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for applying acid mine wastewater to copper-sulfur ore separation, characterized in that: The following steps are involved: S1. Add a certain mass ratio of acidic mine wastewater to the raw ore grinding operation and grind the ore until the content of -74μm ore powder accounts for 75-85wt%; add acidic mine wastewater and industrial water to the material discharged from the mill and adjust the slurry to a slurry concentration of 25-35wt%; S2, adding sodium carbonate to the slurry in step S1 to adjust the slurry; adding calcium hypochlorite, ethylthiocarbamate, sodium sulfite and 2# oil in sequence, stirring and performing copper and sulfur separation and roughing to obtain foam and underflow; S3, adding calcium hypochlorite, ethylthiocarbamate, sodium sulfite and 2# oil to the underflow obtained in step S2 in sequence, stirring, and performing copper-sulfur separation and scavenging I to obtain foam and underflow; S4, adding calcium hypochlorite, ethylthiocarbamate, sodium sulfite and No. 2 oil to the underflow obtained in step S3 in sequence, stirring, and performing copper-sulfur separation and scavenging II to obtain foam and underflow, wherein the copper-sulfur separation and scavenging II foam is returned to the copper-sulfur separation and scavenging I operation; S5. Sodium carbonate is added to the foam obtained in step S2 to adjust the ore pulp, calcium hypochlorite and sodium sulfite in sequence, and copper-sulfur separation and selection I is performed after stirring to obtain foam and underflow; wherein the copper-sulfur separation and selection I underflow and the copper-sulfur separation scavenging selection I foam are returned to the copper-sulfur separation roughing operation together; S6. Sodium carbonate is added to the foam obtained in step S5 to adjust the ore pulp, calcium hypochlorite, and sodium sulfite in sequence, and copper-sulfur separation and concentration II is performed after stirring to obtain foam and underflow; wherein the underflow of copper-sulfur separation and concentration II is returned to the copper-sulfur separation and concentration I operation; S7, adding sodium carbonate to the foam obtained in step S6 to adjust the ore pulp and ethylthiocarbamate in sequence, stirring, and performing copper-sulfur separation and concentration III to obtain foam (i.e., copper concentrate) and underflow; The bottom flow of copper-sulfur separation and concentration III is returned to the copper-sulfur separation and concentration II operation.

2. The method for applying acid mine wastewater to copper-sulfur ore separation according to claim 1, characterized in that: In step S1, the characteristics and main components of acid mine drainage (AMD) are as follows: pH = 2-4, sulfate ion 1000-130000 mg·L -1 , iron ion 200~1000mg·L -1 , copper ion 100~250mg·L -1 , calcium ion 300~600mg·L -1 The mass ratio of AMD to industrial water in the grinding operation and in the slurry preparation of the material discharged from the mill is 1 to 3:

1.

3. The method for applying acid mine wastewater to copper-sulfur ore separation according to claim 1, characterized in that: In step S2, sodium carbonate is used to adjust the pH value of the slurry to 7.5-8.5; based on the mass of the original ore, the amount of calcium hypochlorite added is 500-900 g / t, the amount of ethylthiocarbamate added is 10-30 g / t, the amount of sodium sulfite added is 300-500 g / t, and the amount of No. 2 oil used is 8-14 g / t.

4. The method for applying acid mine wastewater to copper-sulfur ore separation according to claim 1, characterized in that: In step S3, based on the mass of the original ore, the amount of calcium hypochlorite added is 250-450 g / t, the amount of ethylthiocarbamate added is 5-15 g / t, the amount of sodium sulfite added is 150-250 g / t, and the amount of No. 2 oil used is 4-7 g / t.

5. The method for applying acid mine wastewater to copper-sulfur ore separation according to claim 1, characterized in that: In step S4, based on the mass of the original ore, the amount of calcium hypochlorite added is 125-225 g / t, the amount of ethylthiocarbamate added is 2.5-7.5 g / t, the amount of sodium sulfite added is 75-125 g / t, and the amount of 2# oil used is 2-3.5 g / t.

6. The method for applying acid mine wastewater to copper-sulfur ore separation according to claim 1, characterized in that: In step S5, sodium carbonate is used to adjust the pH value of the slurry to 7.5-8.

5. Based on the mass of the original ore, the amount of calcium hypochlorite added is 100-200 g / t, and the amount of sodium sulfite added is 50-100 g / t.

7. The method for applying acid mine wastewater to copper-sulfur ore separation according to claim 1, characterized in that: In step S6, sodium carbonate is used to adjust the pH value of the slurry to 7.5-8.5, and the amount of ethylthiocarbamate added is 4-8 g / t based on the mass of the original ore.

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