CN114011582B - Flotation method for improving beneficiation index of gold-bearing copper sulfide ore - Google Patents

Abstract

The invention discloses a flotation method for improving beneficiation indexes of gold-bearing copper sulfide ores, and belongs to the technical field of metallurgical beneficiation. Based on the technical route of thiosulfate corrosion, sulfide precipitation, hydrogen peroxide, starch coupling inhibition and copper-sulfur selective flotation separation, the gold-containing copper sulfide ore is separated. The flotation method comprises the following steps: (1) roughing; (2) selecting I in a scavenging way; (3) selecting I; (4) b, scavenging II; (5) selecting II; (6) and (5) selecting III. By the flotation method, gold in the carrier mineral can be converted into the independent gold sulfide mineral, the loss of gold in pyrite to tailings is avoided, the synergistic benefit of the combined inhibitor is fully exerted, the quality and the recovery rate of gold and copper concentrate are improved, and the gold-containing copper-sulfur ore is economically, efficiently and cleanly developed and utilized under low alkalinity.

Description

A flotation method for improving beneficiation index of gold-bearing copper sulfide ore

technical field

The invention relates to the technical field of metallurgical beneficiation, in particular to a flotation method for improving the beneficiation index of gold-bearing copper sulfide ore.

Background technique

Copper is widely used in military, electric power, communications, transportation, transportation, light industry, construction, machinery and other industries. The latest statistics show that my country has 95.538 million tons of proven copper resources, of which copper ore reserves with a copper grade below 0.7% account for about 56%, and the average grade of porphyry copper deposits is about 0.5%. . The industrial types of copper ore deposits in my country are relatively complete, and 80% of copper minerals in copper ore with industrial value belong to sulfides. With the deepening of mining and the reduction of easy-to-separate ores, the characteristics of copper sulfide ore resources such as lean, fine, and miscellaneous have become increasingly prominent. The efficient processing of such resources has always been a research hotspot in the field of mineral processing.

Gold-bearing copper-sulfur ore is a relatively common type of sulfide ores. Generally, copper is mainly in the form of chalcopyrite, sulfur is mainly in the form of pyrite, gold mainly exists in the form of natural gold, and copper sulfide minerals and Pyrite is the main carrier mineral for gold. Flotation is an important rough processing link to obtain gold, copper metal and sulfur resources from such ores, and the realization of selective separation of copper and sulfur and comprehensive recovery of gold is the key to flotation of such ores.

At present, the production of gold-bearing copper-sulfur ore generally adopts the lime high-alkali flotation process (pH>11), by adding a large amount of lime to suppress the pyrite, and then adding the sulfide ore collectors xanthate, black medicine, Separation and flotation of copper, gold and sulfur using terpineol oil as a foaming agent. However, this process method has the following problems: (1) Under the condition of high alkali (pH>11), copper and gold minerals will be inhibited to a certain extent, resulting in low recovery rates of copper and gold. The reason is that under the condition of high alkali (pH>11), a large amount of OH ^- will promote the formation of a hydrophilic iron hydroxide film on the surface of chalcopyrite, and the floatability of chalcopyrite will deteriorate, resulting in the recovery rate of copper and gold. lower. At the same time, the gold-bearing carrier mineral pyrite will be seriously inhibited under high alkali conditions, and the surface of the gold monomer mineral will be polluted, resulting in poor floatability. This is the fundamental reason for the low recovery rate of copper and gold in the lime high-alkali flotation process; (2) the use of a large amount of lime is likely to cause serious sludge entrainment, which affects the quality of the concentrate; (3) there is a large amount of lime, It is not easy to control, the pipeline is easy to scale and block, the equipment is corroded, and the mine wastewater is seriously polluted. Increased consumption of agents. It can be seen that the recovery rate of copper and gold in the lime high-alkali flotation process is low, the quality of copper concentrate is poor, and the waste of resources is serious, and it is difficult to realize the economical, efficient and clean development and utilization of gold-bearing copper-sulfur ore resources.

SUMMARY OF THE INVENTION

In view of the above technical problems, the purpose of the present invention is to provide a flotation method for improving the beneficiation index of gold-bearing copper sulfide ore. Through the technical route of "thiosulfate dissolution-sulfide precipitation-hydrogen peroxide+starch coupling inhibition-copper-sulfur selective flotation separation", the gold in carrier minerals is converted into independent gold sulfide minerals, avoiding the occurrence of gold in pyrite The loss to tailings can give full play to the synergistic benefits of combined inhibitors, improve the quality and recovery rate of gold and copper concentrates, and realize economical, efficient and clean development and utilization of gold-bearing copper-sulfur ore under low alkalinity.

For achieving the above object, the present invention provides the following technical solutions:

A flotation method for improving beneficiation index of gold-bearing copper sulfide ore, comprising the steps of:

(1) Roughing: adding combined inhibitor to the pulp, stirring, adding sodium sulfide, stirring, then adding combined collector and foaming agent, and performing roughing after stirring to obtain roughing foam and roughing underflow;

(2) sweep selection 1: add combined inhibitor in rough selection underflow, stir, add sodium sulfide, stir, then add combination collector and foaming agent, carry out sweep selection 1 after stirring, obtain sweep selection 1 foam and sweep selection 1 Select I underflow, sweep and select I foam to return to the roughing operation;

(3) Selection I: add the combined inhibitor to the rough selection foam, stir, then add the combined collector and foaming agent, and perform selection I after stirring to obtain selection I foam and selection I underflow, and select I underflow returns to roughing operation;

(4) Sweeping II: Add the combined inhibitor to the underflow of sweeping I, stir, add sodium sulfide, stir, then add the combined collector and foaming agent, and carry out sweeping II after stirring to obtain sweeping II foam and For tailings, sweep II foam returns to sweep I operation;

(5) Selection II: Add the combined inhibitor to the selected I foam, stir, and then add the combined collector and foaming agent. After stirring, carry out the selection II to obtain the selected II foam and the selected II underflow. Select II underflow to return to Select I operation;

(6) Selection III: Add the combined inhibitor to the selection II foam, stir, and then add the combined collector and foaming agent. After stirring, carry out the selection III to obtain the gold-containing copper concentrate and the selection III underflow. The selection III underflow returns to the selection II operation;

The components of the combined inhibitor include, in parts by mass: 30-50 parts of hydrogen peroxide and 50-70 parts of starch; the components of the combined collector include, in parts by mass: collector Z-20050～ 70 copies and collector BK91630 to 50 copies.

Preferably, the preparation step of the pulp in the step (1) is as follows: grinding the raw ore to a particle size of ≤ 74 μm, the content of which accounts for 75% to 90% of the total mass of the raw ore, and adding sodium carbonate during the grinding process to adjust the pH of the raw pulp To 8-9, and adding 0.03%-0.05% sodium thiosulfate of raw ore mass, after grinding, the obtained raw pulp is slurried to the ore powder mass concentration of 25%-35% to prepare ore pulp.

The invention converts the gold hosted in sulfide ore into independent gold sulfide minerals through thiosulfate dissolution-sulfide precipitation, realizes high-efficiency recovery of gold by combining collectors, and effectively avoids the occurrence of gold in pyrite. Loss of gold to tailings.

Preferably, the foaming agent is 2 ^# oil.

Preferably, in the step (1), the added amount of the combined inhibitor is 0.06% to 0.08% of the raw ore mass, the added amount of sodium sulfide is 0.02% to 0.04% of the raw ore mass, and the added amount of the combined collector is the raw ore mass. 0.004% to 0.008% of the mass, and the added amount of the foaming agent is 0.0005% to 0.0012% of the original ore mass.

Preferably, in the step (2), the added amount of the combined inhibitor is 0.06% to 0.08% of the raw ore mass, the added amount of sodium sulfide is 0.02% to 0.04% of the raw ore mass, and the added amount of the combined collector is the raw ore mass. 0.004% to 0.008% of the mass, and the added amount of the foaming agent is 0.0005% to 0.0012% of the original ore mass.

Preferably, in the step (3), the added amount of the combined inhibitor is 0.01% to 0.03% of the raw ore mass, the added amount of the combined collector is 0.002% to 0.004% of the raw ore mass, and the added amount of the foaming agent is 0.0003% to 0.0006% of the quality of the original ore.

Preferably, in the step (4), the added amount of the combined inhibitor is 0.015% to 0.02% of the raw ore mass, the added amount of sodium sulfide is 0.005% to 0.01% of the raw ore mass, and the added amount of the combined collector is the raw ore mass. 0.001% to 0.002% of the mass, and the added amount of the foaming agent is 0.0002% to 0.004% of the original ore mass.

Preferably, in the step (5), the added amount of the combined inhibitor is 0.005% to 0.015% of the raw ore mass, the added amount of the combined collector is 0.0005% to 0.001% of the raw ore mass, and the added amount of the foaming agent is 0.0001% to 0.0003% of the original ore quality.

Preferably, in the step (6), the added amount of the combined inhibitor is 0.007% to 0.01% of the raw ore mass, the added amount of the combined collector is 0.0002% to 0.0005% of the raw ore mass, and the added amount of the foaming agent is 0.0001% to 0.0003% of the original ore quality.

Preferably, the stirring time of the stirring is 2-4 min.

The beneficial technical effects of the present invention are as follows:

The invention realizes economical, efficient and clean development and utilization of gold-containing copper-sulfur ore under low alkalinity (pH=7-9), and avoids the large amount of lime, equipment and pulp in the traditional lime high alkali-xanthate process. Scaling of pipelines and environmental pollution of mine wastewater.

The hydrogen peroxide in the combined inhibitor used in the invention can oxidize the surface of the pyrite, induce the passivation modification of the pyrite surface, and form a stable cover of the hydrophilic iron component. Among them, starch can be strongly adsorbed on the iron-rich surface of pyrite due to its rich hydroxyl groups, resulting in an increase in the hydrophilicity of the pyrite surface, while the combined inhibitor has less effect on the chalcopyrite surface, which is the realization of copper , An important reason for sulfur selective flotation separation.

The invention improves the recovery rate of gold by means of thiosulfate corrosion-sulfide precipitation. The principle is: in the weak alkaline slurry system of sodium carbonate, sodium thiosulfate can convert the solid-phase gold (Au) hosted in the sulfide minerals into the liquid-phase gold group ([Au(S ₂ O ₃ ) ₃ ] ^3- ), sodium sulfide further precipitates the liquid-phase gold component as an independent gold sulfide mineral (Au ₂ S). The effective recovery of independent gold sulfide minerals will be achieved through the action of collectors.

The combined collector used in the invention can reduce the solubility of the dissolved micelles of the pharmaceutical components and improve the solubility of the pharmaceuticals, so it has strong selectivity for the flotation of copper sulfide ore, can effectively avoid the entrainment of ore slime, and improve the quality and recovery of copper concentrates. Compared with the traditional lime high alkali-xanthate process, the copper grade is increased by 1-2%, the copper recovery rate is increased by 3-5%, the gold grade is increased by 2-3%, and the gold recovery rate is increased by 10-15%.

Description of drawings

Fig. 1 is the process flow chart of the flotation of gold-bearing copper sulfide ore of the present invention.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail, which detailed description should not be construed as a limitation of the invention, but rather as a more detailed description of certain aspects, features, and embodiments of the invention. It should be understood that the terms described in the present invention are only used to describe particular embodiments, and are not used to limit the present invention.

Additionally, for numerical ranges in the present disclosure, it should be understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in that stated range is also encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention relates. Although only the preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.

As used herein, "comprising," "including," "having," "containing," and the like, are open-ended terms, meaning including but not limited to.

The collector Z-200 used in the examples and comparative examples of the present invention was purchased from Tieling Mineral Processing Chemicals Co., Ltd.; the used collector BK916 was purchased from Beijing General Research Institute of Mining and Metallurgy.

The amounts of sodium thiosulfate, sodium sulfide, combined inhibitor, combined collector and foaming agent added in the examples and comparative examples of the present invention are all based on the quality of raw ore, and each substance of corresponding quality is added.

Example 1

The selected raw ore grades in this embodiment are copper 0.75%, sulfur 24.50%, iron 25.32%, and gold 0.28g/t. Its material composition is: the main metal minerals in the ore are mainly pyrite and chalcopyrite, and a small amount of and trace minerals include marcasite, bornite, chalcocite, and blue chalcocite; gangue minerals include pyroxene, Dolomite, quartz, calcite, feldspar, chlorite, epidote, etc. The results of phase analysis of copper in the original ore show that the copper minerals are mainly primary copper minerals (accounting for 92%), and chalcopyrite accounts for 95% of the primary copper minerals.

The combined inhibitor used in this example is obtained by mixing 45 parts of hydrogen peroxide and 65 parts of starch.

The combined collector used in this example is obtained by mixing 60 parts of collector Z-2000 with 40 parts of collector BK91640.

The specific beneficiation steps are as follows:

(1) During the grinding process of raw ore, add sodium carbonate to adjust pH=8.5 and sodium thiosulfate 400g/t, and grind the ore to a particle size of ≤74μm, which accounts for 80% of the raw ore mass; When the concentration of mineral powder is 30wt%, obtain mineral pulp, add combined inhibitor 800g/t, stir for 3min, sodium sulfide 300g/t, stir for 3min, combined collector 60g/t, foaming agent 2 ^# oil 10g/t, stir 3min, carry out rough selection to obtain foam and underflow;

(2) Add 400g/t of combined inhibitor to the underflow obtained by rough selection in step (1), stir for 3min, 150g/t of sodium sulfide, stir for 3min, combined collector 30g/t, foaming agent 2 ^# oil 6g/t , stir for 3min, carry out sweep selection I, obtain foam and underflow, sweep selection I foam back to rough selection operation; add combined inhibitor 200g/t to the foam obtained in step (1) rough selection, stir for 3min, combined collector 30g /t, foaming agent 2 ^# oil 4g/t, stirs 3min, carries out selection 1, obtains foam and underflow, underflow returns to rough selection operation;

(3) add combined inhibitor 200g/t to the underflow obtained by step (2) sweep selection 1, stir 3min, sodium sulfide 80g/t, stir 3min, combined collector 15g/t, foaming agent 2 ^#oil 4g/ t, stir for 3min, carry out sweep II to obtain foam and tailings, sweep II foam and return to sweep I operation; add 100 g/t of combined inhibitor to the foam obtained in step (2) selection I, stir for 3min, combine Collecting agent 15g/t, foaming agent 2 ^# oil 2g/t, stir for 3min, carry out selection II, obtain foam and underflow, and underflow returns to selection I operation;

(4) Add 70g/t of combined inhibitor to step (2) selection II to obtain foam, stir for 3min, combine collector 4g/t, foaming agent 2 ^# oil 2g/t, stir for 3min, carry out selection III, A gold-bearing copper concentrate and underflow are obtained, and the underflow is returned to the Select II operation.

Test results: the copper concentrate grade is 21.88%, the copper recovery rate is 93.12%, the gold grade is 5.8g/t, and the gold recovery rate is 83.15%. Compared with the traditional lime high alkali-xanthate process (using the same flotation process as in Example 1, the difference is that lime is used to replace the combined inhibitor and control the roughing pH=12, ethyl xanthate replaces the combined collector, The dosage of each operation is the same as that of the combined collector, without the addition of sodium thiosulfate and sodium sulfide), the copper grade is increased by 1.8%, the copper recovery rate is increased by 3.2%, the gold grade is increased by 1.5g/t, and the gold recovery rate is increased by 14% .

Example 2

The selected raw ore grades in this embodiment are copper 0.58%, sulfur 22.50%, iron 23.32%, and gold 0.21 g/t. Its material composition is: the main metal minerals in the ore are pyrite and chalcopyrite, and the minor and trace minerals are bornite, chalcocite and blue chalcocite; gangue minerals are dolomite, quartz and calcite. The phase analysis results of copper in the original ore show that the copper minerals include primary copper minerals and secondary copper minerals, mainly primary copper minerals (accounting for 92%), chalcopyrite accounting for 95%, and copper oxide 2%.

The combined inhibitor used in this example is obtained by mixing 50 parts of hydrogen peroxide and 50 parts of starch.

The combined collector used in this example is obtained by mixing 50 parts of collector Z-2000 and 50 parts of collector BK91650.

The specific beneficiation steps are as follows:

(1) During the grinding process of raw ore, add sodium carbonate to adjust pH=9 and sodium thiosulfate 300g/t, and grind the ore to a particle size of ≤74μm, which accounts for 90% of the raw ore quality; When the concentration of mineral powder is 30wt%, obtain mineral pulp, add combined inhibitor 600g/t, stir for 3min, sodium sulfide 150g/t, stir for 3min, combined collector 50g/t, foaming agent 2 ^# oil 10g/t, stir 3min, carry out rough selection to obtain foam and underflow;

(2) Add 300g/t of combined inhibitor to the underflow obtained by rough selection in step (1), stir for 3min, sodium sulfide 80g/t, stir for 3min, combined collector 30g/t, foaming agent 2 ^# oil 5g/t , stir for 3min, carry out sweep selection I, obtain foam and underflow, sweep selection I foam and return to rough selection operation; add combined inhibitor 150g/t to the foam obtained in step (1) rough selection, stir for 3min, combined collector 30g /t, foaming agent 2 ^# oil 5g/t, stirs 3min, carries out selection 1, obtains foam and underflow, underflow returns to rough selection operation;

(3) add combined inhibitor 150g/t to the underflow obtained by step (2) sweep selection 1, stir 3min, sodium sulfide 40g/t, stir 3min, combined collector 15g/t, foaming agent 2 ^#oil 3g/ t, stir for 3min, carry out sweep II to obtain foam and tailings, sweep II foam and return to sweep I operation; add combined inhibitor 80g/t to the foam obtained in step (2) selection I, stir for 3min, combine Collecting agent 15g/t, foaming agent 2 ^# oil 2g/t, stir for 3min, carry out selection II, obtain foam and underflow, and underflow returns to selection I operation;

(4) Add 40g/t of combined inhibitor to step (2) selection II to obtain foam, stir for 3min, combine collector 8g/t, foaming agent 2 ^# oil 3g/t, stir for 3min, carry out selection III, A gold-bearing copper concentrate and underflow are obtained, and the underflow is returned to the Select II operation.

Test results: the copper concentrate grade is 20.20%, the copper recovery rate is 91.32%, the gold grade is 5.3g/t, and the gold recovery rate is 81.5%. Compared with the traditional lime high alkali-xanthate process (using the same flotation process as in Example 2, the difference is that lime is used to replace the combined inhibitor and control the roughing pH=12, ethyl xanthate replaces the combined collector, The dosage of each operation is the same as that of the combined collector, without the addition of sodium thiosulfate and sodium sulfide), the copper grade is increased by 1.3%, the copper recovery rate is increased by 2.8%, the gold grade is increased by 1.2g/t, and the gold recovery rate is increased by 12% .

Comparative Example 1

The same raw ore and flotation process as in Example 1 are used, the difference is that the combined inhibitor in each step is replaced with starch of the same quality.

Test results: the copper concentrate grade is 19.21%, the copper recovery rate is 91.2%, the gold grade is 4.2g/t, and the gold recovery rate is 82.5%.

Comparative Example 2

The same raw ore and flotation process as in Example 1 were used, except that the collector BK916 of the same quality was used to replace the combined collector in each step.

Test results: the copper concentrate grade is 19.3%, the copper recovery rate is 91.45%, the gold grade is 4.8g/t, and the gold recovery rate is 79.5%.

Comparative Example 3

The same raw ore and flotation process as in Example 1 were adopted, except that no sodium thiosulfate was added.

Test results: the grade of copper concentrate is 19.5%, the recovery rate of copper is 91.45%, the grade of gold is 4.2g/t, and the recovery rate of gold is 61.5%.

The above-mentioned embodiments are only to describe the preferred modes of the present invention, but not to limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art can make various modifications to the technical solutions of the present invention. Variations and improvements should fall within the protection scope determined by the claims of the present invention.

Claims (8)

1. A flotation method for improving the beneficiation index of gold-bearing copper sulfide ore is characterized by comprising the following steps:

(1) roughing: adding a combined inhibitor into the ore pulp, stirring, adding sodium sulfide, stirring, adding a combined collecting agent and a foaming agent, stirring, and then performing roughing to obtain roughing foam and roughing underflow;

(2) and (3) scavenging I: adding a combined inhibitor into the roughing underflow, stirring, adding sodium sulfide, stirring, adding a combined collecting agent and a foaming agent, stirring, and then carrying out scavenging I to obtain scavenging I foam and scavenging I underflow, wherein the scavenging I foam returns to the roughing operation;

(3) selection I: adding a combined inhibitor into the roughing foam, stirring, adding a combined collecting agent and a foaming agent, stirring, and then carrying out the fine separation I to obtain a fine separation I foam and a fine separation I underflow, and returning the fine separation I underflow to the roughing operation;

(4) and (4) scavenging II: adding a combined inhibitor into the bottom flow of the scavenging section I, stirring, adding sodium sulfide, stirring, adding a combined collecting agent and a foaming agent, stirring, then carrying out scavenging section II to obtain foams of the scavenging section II and tailings, and returning the foams of the scavenging section II to the operation of the scavenging section I;

(5) and (4) selecting II: adding a combined inhibitor into the foam I, stirring, adding a combined collecting agent and a foaming agent, stirring, and then carrying out concentration II to obtain foam II and underflow II, and returning the underflow II to the operation of concentration I;

(6) selecting III: adding a combined inhibitor into the foam of the concentration II, stirring, adding a combined collecting agent and a foaming agent, stirring, and then performing concentration III to obtain gold-containing copper concentrate and a bottom flow of the concentration III, and returning the bottom flow of the concentration III to the operation of the concentration II;

the combined inhibitor comprises the following components in parts by weight: 30-50 parts of hydrogen peroxide and 50-70 parts of starch; the combined collector comprises the following components in parts by mass: collecting agent Z-20050-70 parts and collecting agent BK 91630-50 parts;

the preparation steps of the ore pulp in the step (1) are as follows: grinding raw ore until the content of ore powder with the particle size of less than or equal to 74 mu m accounts for 75-90% of the total mass of the raw ore, adding sodium carbonate to adjust the pH of the primary pulp to 8-9 in the ore grinding process, adding sodium thiosulfate with the mass of 0.03-0.05% of the mass of the raw ore, after the ore grinding is finished, mixing the obtained primary pulp until the mass concentration of the ore powder is 25-35%, and preparing ore pulp.

2. The method of claim 1The flotation method for improving the mineral separation index of the gold-bearing copper sulfide ore is characterized in that the foaming agent is 2 ^# And (3) oil.

3. A flotation method for improving the beneficiation index of gold-containing copper sulfide ore according to claim 1, wherein in the step (1), the addition amount of the combined inhibitor is 0.06% -0.08% of the mass of the raw ore, the addition amount of the sodium sulfide is 0.02% -0.04% of the mass of the raw ore, the addition amount of the combined collector is 0.004% -0.008% of the mass of the raw ore, and the addition amount of the foaming agent is 0.0005% -0.0012% of the mass of the raw ore.

4. The flotation method for improving the beneficiation index of the gold-bearing copper sulfide ore according to claim 1, wherein in the step (2), the addition amount of the combined inhibitor is 0.06% -0.08% of the mass of the raw ore, the addition amount of the sodium sulfide is 0.02% -0.04% of the mass of the raw ore, the addition amount of the combined collector is 0.004% -0.008% of the mass of the raw ore, and the addition amount of the foaming agent is 0.0005% -0.0012% of the mass of the raw ore.

5. The flotation method for improving the beneficiation index of the gold-bearing copper sulfide ore according to claim 1, wherein in the step (3), the addition amount of the combined inhibitor is 0.01% -0.03% of the mass of the raw ore, the addition amount of the combined collector is 0.002% -0.004% of the mass of the raw ore, and the addition amount of the foaming agent is 0.0003% -0.0006% of the mass of the raw ore.

6. The flotation method for improving the beneficiation index of the gold-bearing copper sulfide ore according to claim 1, wherein in the step (4), the addition amount of the combined inhibitor is 0.015% -0.02% of the mass of the raw ore, the addition amount of the sodium sulfide is 0.005% -0.01% of the mass of the raw ore, the addition amount of the combined collector is 0.001% -0.002% of the mass of the raw ore, and the addition amount of the foaming agent is 0.0002% -0.004% of the mass of the raw ore.

7. The flotation method for improving the beneficiation index of gold-bearing copper sulfide ore according to claim 1, wherein in the step (5), the addition amount of the combined inhibitor is 0.005% -0.015% of the mass of the raw ore, the addition amount of the combined collector is 0.0005% -0.001% of the mass of the raw ore, and the addition amount of the foaming agent is 0.0001% -0.0003% of the mass of the raw ore.

8. The flotation method for improving the beneficiation index of gold-bearing copper sulfide ore according to claim 1, wherein in the step (6), the addition amount of the combined inhibitor is 0.007% to 0.01% of the mass of the raw ore, the addition amount of the combined collector is 0.0002% to 0.0005% of the mass of the raw ore, and the addition amount of the foaming agent is 0.0001% to 0.0003% of the mass of the raw ore.

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