Comprehensive utilization method of copper tailings

Abstract

The invention relates to a comprehensive utilization method of copper tailings, which comprises the following steps: S1, carrying out mineral separation on the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings; performing flotation on the quartz tailings to obtain high-purity quartz and flotation quartz; s2, the middlings in the step S1 and flotation quartz with the weight not lower than 90% are mixed, silicon oxide and iron oxide are separated, and a mixture is obtained; s3, mixing the mixture in the step S2 with the neutralized slag and limestone, and roasting at 1000-1450 DEG C to obtain cement clinker; the neutralization slag is solid waste generated after acid wastewater and / or waste gas are / is neutralized by lime. According to the method disclosed by the invention, the effective components in the middlings and the quartz tailings after the copper tailings are beneficiated can be efficiently utilized to obtain the cement meeting the quality requirement of GB 175-2023, so that the copper tailings and the neutralization slag are massively absorbed, the resource shortage is effectively relieved, the environmental problem caused by solid waste stockpiling is reduced, and the ecological benefit, the economic benefit and the social benefit are remarkable.

Description

Technical Field

[0001] The present invention relates to the technical field of tailings resource utilization, and in particular to a comprehensive utilization method of copper tailings. Background Art

[0002] The large-scale development of global mineral resources inevitably generates large quantities of copper tailings. Current technologies preclude their effective recycling and reuse, and therefore they are often discharged directly into tailings ponds. This accumulation of copper tailings wastes resources, occupies significant land resources, and pollutes the environment. Furthermore, chemical and metallurgical production generates significant amounts of acidic wastewater and waste gas. These are typically treated with lime neutralization to meet standards before being reused. However, this treatment process produces a significant amount of waste residue (neutralized residue, primarily composed of CaSO₄·2H₂O and CaCO₃), which must be stored in tailings ponds, increasing the storage pressure on these ponds.

[0003] Most copper mines in China produce associated solid wastes in the form of copper tailings and neutralization slag. However, these wastes are typically treated separately, often failing to achieve systematic and efficient disposal and incurring significant storage and transportation costs. Therefore, the comprehensive utilization of copper tailings and neutralization slag, achieving large-scale disposal of both wastes and improving resource utilization, is of great significance for enhancing economic, social, and ecological benefits and promoting the green and high-quality development of mines. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a comprehensive utilization method of copper tailings.

[0005] The technical solution adopted in the present invention is:

[0006] The present invention provides a comprehensive utilization method of copper tailings, comprising the following steps:

[0007] S1, beneficiating the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings;

[0008] The quartz tailings are flotated to obtain high-purity quartz and flotation quartz;

[0009] S2, mixing the middlings described in step S1 with not less than 90% by weight of the flotation quartz and separating silicon oxide and iron oxide to obtain a mixture;

[0010] S3, mixing the mixture of step S2 with neutralized slag and limestone and calcining the mixture at 1000-1450° C. to obtain cement clinker;

[0011] The neutralized slag is solid waste generated after acidic wastewater and / or waste gas is neutralized by lime.

[0012] The beneficial effects of the present invention are:

[0013] (1) The method of the present invention can efficiently utilize the effective components in the middlings and quartz tailings after the beneficiation of copper tailings. First, flotation is performed to avoid the loss of high-purity quartz in the quartz tailings. Then, the middlings and flotation quartz are pretreated to further reduce the loss of valuable minerals (silicon oxide and iron oxide). Then, the remaining mixture is compounded with neutralization slag and limestone as a raw material for producing cement clinker, thereby obtaining cement that meets the quality requirements of GB 175-2023, thereby realizing the bulk consumption of copper tailings and neutralization slag, effectively alleviating resource shortages, and reducing environmental problems caused by solid waste storage, with significant ecological, economic and social benefits.

[0014] (2) In addition to obtaining cement clinker, the method of the present invention can also use the alunite and quartz tailings obtained from the copper tailings beneficiation to obtain high-value-added boehmite and industrial silicon, respectively, and the quality of the obtained industrial silicon meets the GB / T 2881-2014 standard; at the same time, the tail gas generated during the cement clinker roasting process can also be used to prepare sulfuric acid and meet the GB / T 534-2014 quality standard, further improving the resource utilization rate and economic benefits of the copper tailings.

[0015] Preferably, in step S1, the beneficiation process is: firstly flotation the copper tailings one or more times to obtain a copper rough concentrate, and then pre-classify, regrind, perform a roughing operation and perform two scavenging operations on the copper rough concentrate.

[0016] Preferably, in step S1, the alunite is subjected to impurity removal, hydrothermal reaction, recrystallization, and calcination to obtain high-purity alumina.

[0017] Preferably, in step S1, the high-purity quartz is subjected to hydrogen or carbothermal reduction treatment to obtain industrial silicon.

[0018] Preferably, in step S2, the process of mixing and separating silicon oxide and iron oxide is: mixing the middlings and the flotation quartz, performing regrinding and inspection and classification, returning the obtained inspection and classification sedimentation to regrinding, and performing one roughing and two flotation on the regrinded product to separate silicon oxide and iron oxide.

[0019] Preferably, in step S3, the neutralized slag is pretreated, and the pretreatment is thermal reduction under graphite.

[0020] More preferably, the weight ratio of the neutralized slag to the graphite is 100:1-10;

[0021] The temperature of the thermal reduction is 900-1200°C.

[0022] Preferably, in step S3, the weight ratio of the mixture, the neutralized slag, and the limestone is 1-2:0.5-1.2:0.8-4.

[0023] Preferably, in step S3, the tail gas generated by the cement clinker roasting and / or the neutralized slag pretreatment is used for dry process production of sulfuric acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic flow chart of the comprehensive utilization method of copper tailings according to Example 6 of the present invention. DETAILED DESCRIPTION

[0025] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0026] The present invention provides a comprehensive utilization method of copper tailings, comprising the following steps:

[0027] S1, beneficiating the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings;

[0028] Flotation of quartz tailings to obtain high-purity quartz and flotation quartz;

[0029] S2, mixing the ore from step S1 with not less than 90% by weight of flotation quartz and separating silicon oxide and iron oxide to obtain a mixture;

[0030] S3, mixing the mixture from step S2 with neutralized slag and limestone and calcining the mixture at 1000-1450° C. to obtain cement clinker;

[0031] Neutralized slag is the solid waste produced after acidic wastewater and / or waste gas is neutralized by lime.

[0032] In the present invention, through the methods of graded mineral processing, roasting, etc., the effective components in the copper tailings and neutralized slag are fully utilized to achieve the full-scale disposal of the two solid wastes, and the storage problem of the copper tailings and neutralized slag is solved from the source. In step S1, a cationic collector (such as dodecylamine) can be used to float the quartz tailings, which is beneficial to the selective separation of quartz and reduce its loss; in step S2, the ratio of the middling ore and the flotation quartz is controlled to ensure that the silicon and aluminum content in the screened mixture meets the requirements of the subsequent cement clinker. For example, 90-98% by weight of the flotation quartz can be mixed with the middling ore, such as the middling ore can be mixed with 90% by weight of the flotation quartz and 92% by weight of the flotation stone. quartz, 94% by weight of flotation quartz, 95% by weight of flotation quartz, 96% by weight of flotation quartz, and 98% by weight of flotation quartz are mixed and silicon oxide and iron oxide are separated; in step S3, the calcination temperature of the cement clinker can be any value among 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1250°C, 1300°C, 1400°C, and 1450°C, and the calcination time can be 0.5-4 hours. The above list is not particularly limited.

[0033] In a preferred embodiment, in step S1, the beneficiation process is as follows: first, the copper tailings are subjected to one or more flotation to obtain a copper rough concentrate, and then the copper rough concentrate is subjected to pre-grading, regrinding, one roughing and two scavenging. In the present invention, the copper tailings are first pre-enriched by flotation to quickly separate the copper rough concentrate, thereby reducing the subsequent processing load; then, a "pre-grading-regrinding" closed-loop cycle is adopted for fine treatment to ensure that the minerals are fully dissociated; finally, a combination of multi-stage flotation (roughing-scavenging) is used for precise sorting to achieve efficient separation of four target minerals: alunite, sulfur concentrate, middlings and quartz tailings. In addition, during the regrinding process, an appropriate amount of adjusting agent (such as lime, etc.) can be added to adjust the slurry properties and promote the dissociation of the target minerals.

[0034] In a preferred embodiment, in step S1, alunite is subjected to impurity removal, hydrothermal reaction, recrystallization, and calcination to obtain high-purity alumina. In the present invention, acid leaching or alkaline leaching can be used to remove impurities, and then the alunite after impurity removal is decomposed under hydrothermal conditions (the hydrothermal temperature can be 200-250°C and the hydrothermal time can be 4-8 hours), and then the aluminum hydroxide is further separated and purified by recrystallization, and finally decomposed by high-temperature calcination (the calcination temperature can be 1200-1400°C and the calcination temperature can be 2-4 hours) to obtain high-purity alumina with a purity of ≥99.99%, which can further be used to obtain high-value boehmite, or the high-purity alumina can also be used for other purposes, such as as a catalyst support.

[0035] In a preferred embodiment, in step S1, high-purity quartz undergoes hydrogen or carbothermal reduction to obtain industrial silicon. In the present invention, hydrogen or carbothermal reduction can efficiently convert high-purity quartz into industrial silicon, with quality meeting the GB / T 2881-2014 standard. Industrial silicon can be further processed into organosilicon products, which are widely used in fields such as construction and electronics. It can also be further purified into semiconductor silicon (such as single crystal silicon and polycrystalline silicon) for use in semiconductor devices. The reducing agent for carbothermal reduction can be petroleum coke or charcoal, and the reduction treatment temperature can be 1000-2000°C for 3-6 hours.

[0036] In a preferred embodiment, in step S2, the process for mixing and separating silicon oxide and iron oxide is as follows: middlings and flotation quartz are mixed, regrinded, and inspected and classified; the resulting inspected and classified grit is returned to regrinding; and the regrinded product is subjected to a single roughing separation and two flotation separations to separate silicon oxide and iron oxide. In the present invention, by subjecting the middlings and flotation quartz to an advanced treatment process of "regrinding-inspection and classification-roughing-flotation," the loss of valuable minerals is further reduced. Furthermore, the remaining mixed minerals can continue to be used as a silicon source for cement clinker synthesis, thereby improving overall resource utilization.

[0037] In a preferred embodiment, in step S3, the neutralized slag is pretreated, and the pretreatment is thermal reduction under graphite. In the present invention, the main chemical components of the neutralized slag are CaSO4·2H2O and CaCO3. The high-temperature reduction treatment removes sulfur in the form of SO2, which can be further recycled to produce sulfuric acid, improving economic benefits while reducing sulfur pollution to the environment. On the other hand, the CaO obtained by the high-temperature reduction reaction is more reactive as a calcium source than CaSO4 that has not been pretreated and decomposed. It can directly participate in the formation of clinker minerals (such as C3S and C2S), reduce the clinker firing temperature, and improve the early strength of subsequent cement.

[0038] In a more preferred embodiment, the weight ratio of the neutralized slag to the graphite is 100:1-10;

[0039] The temperature of thermal reduction is 900-1200°C.

[0040] In the present invention, for example, the weight ratio of the neutralized slag and graphite can be any value of 100:1, 100:3, 100:5, 100:7, 100:10, etc.; the temperature of thermal reduction can be 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, and the time of thermal reduction can be 40-140min, but is not limited to the above-mentioned ones.

[0041] In a preferred embodiment, in step S3, the weight ratio of the mixture, the neutralized slag, and the limestone is 1-2:0.5-1.2:0.8-4. In the present invention, the mixture can provide a silicon source and an aluminum source to replace traditional siliceous raw materials; the neutralized slag can provide a calcium source and an iron source to reduce the amount of limestone used; the limestone supplements the calcium source when the neutralized slag CaO is insufficient. Under the above raw material ratio, the cement clinker obtained meets the requirements of traditional cement clinker. In addition, the above cement clinker can be prepared with gypsum and admixtures in the following weight ratio: 80-90% cement clinker, 3-10% gypsum, and 5-20% admixture. The performance of the obtained cement meets the quality requirements of GB 175-2023.

[0042] In a preferred embodiment, in step S3, the tail gas generated by cement clinker roasting and / or neutralized slag pretreatment is used to produce sulfuric acid by a dry process. In the present invention, the volume fraction of SO₂ in the tail gas is 5-20%. The dry process for producing sulfuric acid can specifically employ the following process: flue gas purification, purified gas compression, gas preheating, two-stage conversion and two-stage absorption, and tail gas treatment. The resulting sulfuric acid meets the quality standard of GB / T 534-2014.

[0043] Example 1

[0044] A comprehensive utilization method of copper tailings comprises the following steps:

[0045] S1, beneficiating the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings;

[0046] The beneficiation process is as follows: first, the copper tailings are subjected to a flotation process to obtain a copper rough concentrate, and then the copper rough concentrate is subjected to pre-classification, regrinding, a roughing process and two scavenging processes;

[0047] Quartz tailings are flotated to obtain high-purity quartz and flotation quartz.

[0048] S2, mixing the ore from step S1 with 95% by weight of flotation quartz and separating silicon oxide and iron oxide to obtain a mixture;

[0049] The process of mixing and separating silicon oxide and iron oxide is as follows: the middlings and flotation quartz are mixed and regrinded and inspected and classified, the inspection and classified sediment is returned to regrinding, and the regrinded product is subjected to one roughing and two flotation to separate silicon oxide and iron oxide.

[0050] S3, mixing the mixture from step S2 with neutralized slag and limestone in a weight ratio of 1.5:0.6:3.5 and calcining the mixture at 1450° C. for 2 h to obtain cement clinker;

[0051] Neutralized slag is the solid waste produced after acidic wastewater and / or waste gas is neutralized by lime;

[0052] The tail gas (SO2 volume fraction of 11%) generated by cement clinker roasting is used for dry production of sulfuric acid. The specific process is: flue gas purification, purified gas compression, gas preheating, two-transfer and two-absorption, and tail gas treatment.

[0053] Example 2

[0054] The main difference between this example and Example 1 is that the neutralized slag in step S3 is pretreated by thermal reduction under graphite. The weight ratio of the neutralized slag to graphite is 100:2, and the thermal reduction temperature is 1100°C for 40 minutes. Furthermore, the tail gas generated by the neutralized slag pretreatment is also used for dry-process sulfuric acid production, with the total SO₂ volume fraction in the tail gas being 15%. The remaining steps remain unchanged.

[0055] Example 3

[0056] The main difference between this embodiment and embodiment 2 is that the amounts of the components and the process parameters are different. The other steps remain unchanged.

[0057] A comprehensive utilization method of copper tailings comprises the following steps:

[0058] S1, beneficiating the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings;

[0059] The beneficiation process is as follows: first, the copper tailings are subjected to a flotation process to obtain a copper rough concentrate, and then the copper rough concentrate is subjected to pre-classification, regrinding, a roughing process and two scavenging processes;

[0060] Quartz tailings are flotated to obtain high-purity quartz and flotation quartz.

[0061] S2, mixing the ore from step S1 with 90% by weight of flotation quartz and separating silicon oxide and iron oxide to obtain a mixture;

[0062] The process of mixing and separating silicon oxide and iron oxide is as follows: the middlings and flotation quartz are mixed and regrinded and inspected and classified, the inspection and classified sediment is returned to regrinding, and the regrinded product is subjected to one roughing and two flotation to separate silicon oxide and iron oxide.

[0063] S3. Pre-treating the neutralized slag by thermal reduction under graphite; the thermal reduction process comprises mixing the neutralized slag with graphite in a weight ratio of 100:10, and thermally reducing the mixture at 1200° C. for 80 min;

[0064] The mixture from step S2 was mixed with pretreated neutralized slag and limestone in a weight ratio of 1.2:0.8:3.5 and calcined at 1380° C. for 2 h to obtain cement clinker;

[0065] Neutralized slag is the solid waste produced after acidic wastewater and / or waste gas is neutralized by lime;

[0066] The tail gas (SO2 volume fraction of 18%) generated by cement clinker roasting and neutralization slag pretreatment is used for dry production of sulfuric acid. The specific process is: flue gas purification, purified gas compression, gas preheating, two-transfer and two-absorption, and tail gas treatment.

[0067] Example 4

[0068] The main difference between this embodiment and embodiment 3 is that the alunite in step S1 is further subjected to impurity removal (acid leaching), hydrothermal reaction (at 200°C for 6 hours), recrystallization, and calcination (at 1300°C for 2.5 hours) to obtain high-purity alumina. The remaining steps remain unchanged.

[0069] Example 5

[0070] The main difference between this embodiment and embodiment 3 is that the high-purity quartz in step S1 is further subjected to carbothermal reduction to obtain industrial silicon (high-purity quartz and petroleum coke are mixed in a weight ratio of 1:0.7 and reduced at 1800° C. for 5 hours). The remaining steps remain unchanged.

[0071] Example 6

[0072] Reference Figure 1 A method for comprehensive utilization of copper tailings comprises the following steps:

[0073] S1, beneficiating the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings;

[0074] The beneficiation process is as follows: first, the copper tailings are subjected to a flotation process to obtain a copper rough concentrate, and then the copper rough concentrate is subjected to pre-classification, regrinding, a roughing process and two scavenging processes;

[0075] Alunite is processed through impurity removal (acid leaching), hydrothermal reaction (220°C for 5h), recrystallization, and calcination (1300°C for 3h) to obtain high-purity alumina.

[0076] Flotation of quartz tailings to obtain high-purity quartz and flotation quartz;

[0077] Industrial silicon is obtained by carbon thermal reduction of high-purity quartz. The specific process is: high-purity quartz and petroleum coke are mixed in a weight ratio of 1:0.7, and then reduced at 1900℃ for 5 hours to obtain industrial silicon.

[0078] S2, mixing the ore from step S1 with 94% by weight of flotation quartz and separating silicon oxide and iron oxide to obtain a mixture;

[0079] The process of mixing and separating silicon oxide and iron oxide is as follows: the middlings and flotation quartz are mixed and regrinded and inspected and classified, the inspection and classified sediment is returned to regrinding, and the regrinded product is subjected to one roughing and two flotation to separate silicon oxide and iron oxide.

[0080] S3, pre-treating the neutralized slag by thermal reduction under graphite; the thermal reduction process is: mixing the neutralized slag with graphite in a weight ratio of 100:7, and thermally reducing at 1150° C. for 60 minutes;

[0081] The mixture from step S2 was mixed with pretreated neutralized slag and limestone in a weight ratio of 1.5:0.8:4 and calcined at 1400° C. for 2 h to obtain cement clinker;

[0082] Neutralized slag is the solid waste produced after acidic wastewater and / or waste gas is neutralized by lime;

[0083] The tail gas (SO2 volume fraction of 17%) generated by cement clinker roasting and neutralization slag pretreatment is used for dry production of sulfuric acid. The specific process is: flue gas purification, purified gas compression, gas preheating, two-transfer and two-absorption, and tail gas treatment.

[0084] The cement clinker prepared in Examples 1-3 and 6 was mixed with gypsum and admixtures according to the following weight ratio: 80% cement clinker, 5% gypsum, and 15% admixture, and the cement was obtained after ball milling, and the performance test was performed. The compressive strength of the cement was tested according to GB / T17671-2021 "Test method for strength of cement mortar (ISO method)"; the setting time and stability of the cement were tested according to GB / T 1346-2011 "Test method for water consumption, setting time, and stability of cement standard consistency". The sulfuric acid prepared in Examples 1-3 was measured for sulfuric acid concentration (mass fraction) according to GB / T 534-2014 "Industrial sulfuric acid".

[0085] The alumina content of the high-purity alumina prepared in Example 4 and Example 6 was determined according to GB / T 6609 “Chemical analysis methods and physical property determination methods of alumina”.

[0086] The content of each element in the industrial silicon prepared in Example 5 and Example 6 was determined according to GB / T 14849 series "Chemical Analysis Methods for Industrial Silicon".

[0087] The test results are recorded in Table 1.

[0088] Table 1

[0089]

[0090]

[0091] As shown in Table 1, the mechanical properties, setting time, and other indicators of the cement obtained from the cement clinkers of Examples 1-6 of the present invention meet the quality requirements of GB175-2023 "General Portland Cement", and the industrial sulfuric acid obtained from the tail gas generated during the production process meets the quality standard of GB / T 534-2014 "Industrial Sulfuric Acid". At the same time, a comparison of Examples 1-3 and 6 shows that compared with Example 1, Example 2 uses pretreated neutralized slag as cement clinker. The neutralized slag subjected to high-temperature graphite reduction can convert part of the calcium sulfate therein into active calcium oxide, which is conducive to the formation of silicate minerals, thereby improving the early strength and initial setting time of the cement. In addition, the pretreated neutralized slag produces more SO2-containing tail gas, and the mass fraction of the subsequently produced sulfuric acid is higher. In Examples 3 and 6, due to the use of a larger amount of graphite and a higher reduction treatment temperature, the pretreated neutralized slag contains more active calcium oxide than Example 2, and therefore the performance of the resulting cement is further improved. The high-purity alumina obtained in Examples 4 and 6 has a purity of up to 99.99% and can be further used to obtain high-value boehmite; the industrial silicon obtained in Examples 5 and 6 meets the quality standard of GB / T 2881-2014 "Industrial Silicon" and can be further used to obtain organic silicon.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for comprehensive utilization of copper tailings, characterized in that: The following steps are involved: S1, beneficiating the copper tailings to obtain alunite, sulfur concentrate, middlings and quartz tailings; The quartz tailings are flotated to obtain high-purity quartz and flotation quartz; S2, mixing the middlings described in step S1 with not less than 90% by weight of the flotation quartz and separating silicon oxide and iron oxide to obtain a mixture; S3, mixing the mixture of step S2 with neutralized slag and limestone and calcining the mixture at 1000-1450° C. to obtain cement clinker; The neutralized slag is solid waste generated after acidic wastewater and / or waste gas is neutralized by lime.

2. The comprehensive utilization method of copper tailings as claimed in claim 1, wherein In step S1, the beneficiation process is as follows: firstly, the copper tailings are subjected to one or more flotation steps to obtain a copper rough concentrate, and then the copper rough concentrate is subjected to pre-classification, regrinding, one roughing step and two scavenging steps.

3. The comprehensive utilization method of copper tailings as claimed in claim 1, wherein In step S1, the alunite is subjected to impurity removal, hydrothermal reaction, recrystallization, and calcination to obtain high-purity alumina.

4. The comprehensive utilization method of copper tailings as claimed in claim 1, wherein In step S1, the high-purity quartz is subjected to hydrogen or carbothermal reduction treatment to obtain industrial silicon.

5. The comprehensive utilization method of copper tailings according to claim 1, wherein In step S2, the process of mixing and separating silicon oxide and iron oxide is as follows: the middlings and the flotation quartz are mixed and regrinded and inspected and classified, the obtained inspection and classified grit is returned to regrinding, and the regrinded product is subjected to one roughing and two flotation to separate silicon oxide and iron oxide.

6. The comprehensive utilization method of copper tailings according to claim 1, wherein In step S3, the neutralized slag is pretreated, and the pretreatment is thermal reduction under graphite.

7. The comprehensive utilization method of copper tailings according to claim 6, wherein: The weight ratio of the neutralized slag to the graphite is 100:1-10; The temperature of the thermal reduction is 900-1200°C.

8. The comprehensive utilization method of copper tailings according to claim 1, wherein In step S3, the weight ratio of the mixture, the neutralized slag, and the limestone is 1-2:0.5-1.2:0.8-4.

9. The comprehensive utilization method of copper tailings according to claim 1 or 6, wherein: In step S3, the tail gas generated by the cement clinker roasting and / or the neutralized slag pretreatment is used for dry process production of sulfuric acid.

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