Sulfur suppression flotation method for mixed sulfur concentrate in low dissolved oxygen environment

Abstract

The invention discloses a low dissolved oxygen environment mixed sulfur concentrate sulfur suppression flotation method. The method comprises the steps that mixed sulfur concentrate and kerosene are mixed and then ground, part of an inhibitor is added in the ore grinding process, and concentrated ore pulp is obtained; after water is added into the concentrated ore pulp for pulp mixing, the remaining inhibitor and the remaining alkaline agent are sequentially added to adjust the DO value, the pH value and the OPR value of the ore pulp, and then a foaming agent is added for roughing; after a collecting agent is added into tailings obtained through roughing, scavenging is conducted, and scavenged middlings and sulfur tailings are obtained; and the alkaline agent is added into concentrate obtained through roughing again to adjust the pH value, then concentration is conducted, copper-molybdenum concentrate and concentration middling are obtained, the scavenging middling and the concentration middling are combined and returned to the pulp mixing process, and circulation operation is conducted. According to the method, flotation of the pyrite is inhibited in a DO value-pH value-ORP value combined regulation and control mode, efficient inhibition of the pyrite is achieved under the conditions of high altitude, low dissolved oxygen and low alkalinity, the grade of the copper-molybdenum concentrate is remarkably improved, and the economic benefits of mine development are effectively improved while the environment of a high-altitude mine is protected.

Description

Technical Field

[0001] The invention relates to a sulfur suppression flotation method for a mixed sulfur concentrate, in particular to a sulfur suppression flotation method for a mixed sulfur concentrate in a low dissolved oxygen environment, and belongs to the technical field of mineral flotation. Background Art

[0002] Copper is known as the king of non-ferrous metals and is widely used in the electrical industry. With the development of new energy and artificial intelligence, the demand for copper resources is also increasing. Sulfide copper mines in high-altitude areas have attracted more and more attention due to their polymetallic and huge reserves, but mine development is difficult due to the low oxygen, low pressure environment and the inconvenience of transportation in high-altitude areas. The sulfide minerals in high-altitude copper mines are basically chalcopyrite and pyrite. Since chalcopyrite has better natural hydrophobicity than pyrite, it is easier to adsorb collectors and has better floatability. The separation flotation process usually focuses on inhibiting pyrite. However, due to the lower air pressure in high-altitude areas, the dissolved oxygen (DO) in the slurry is relatively low, which will affect the mineral interface. Studies have shown that the low dissolved oxygen environment in high-altitude areas is conducive to reducing the formation of hydroxylation on the surface of pyrite and producing more hydrophobic sulfur. The reduction of hydroxyl compounds also provides more adsorption sites for collectors, which is conducive to increasing the adsorption amount and leading to enhanced hydrophobicity of pyrite. The low dissolved oxygen environment at high altitudes has been shown to be beneficial to pyrite flotation, which also increases the difficulty of pyrite flotation inhibition.

[0003] There are currently two main directions for inhibiting pyrite: one is to use oxidation and organic inhibitors to enhance surface hydroxylation, and the other is to reduce the surface hydrophobicity by reducing the adsorption of collectors. Although there are differences between the two methods, they both aim to expand the difference in surface hydrophobicity between pyrite and chalcopyrite in order to achieve separation. Theoretically, the adsorption of collectors on the surface of sulfide ores is an electrochemical process that can be controlled by adjusting the slurry potential. The most direct method is to increase the pH value. In this case, a significant decrease in the pulp potential will reduce the adsorption of the collector and also help promote surface hydroxylation. Among them, the most representative process in production is the lime high alkali (pH>12.0) sulfur inhibition process. The strong alkaline environment easily causes the formation of hydrophilic ferrous hydroxide and ferric hydroxide precipitates on the surface of pyrite. Ca 2+The surface reaction generates hydrophilic and insoluble substances such as CaS04, which reduces the adsorption of the collector, thereby achieving the inhibition of pyrite. Lime is usually added in the form of lime milk. Due to its low solubility, it is very easy to cause pipeline blockage and equipment corrosion problems; lime will also calcify the slurry, the foam will become sticky and the fluidity will deteriorate, and it will easily carry gangue minerals, resulting in reduced sorting; a large amount of lime will lead to a poor recovery effect of associated rare metals, reducing the overall economic benefits; transportation is inconvenient in high-altitude areas, and a large amount of lime will not only have high transportation costs, but also pollute the environment. Therefore, most research focuses on the development of low-alkali, high-efficiency, green sulfur inhibition processes.

[0004] At present, most of the research is basically carried out in low-altitude environments, and even fewer studies are conducted in high-altitude areas. Lower DO values ​​will weaken surface corrosion, but the oxidation of surface hydrophobic sulfur still requires appropriate dissolved oxygen to participate in oxidation. It seems that controlling the pH of the slurry alone is not enough. It seems more feasible to use oxidation method in combination with organic inhibitors. Due to the relatively fragile ecological environment and inconvenient transportation in high-altitude areas, mining development needs to consider the use of safe, environmentally friendly, convenient and efficient production processes. In view of the problem that pyrite is difficult to suppress in high-altitude and low-dissolved oxygen environments, a mineral processing process with advanced technology, good sorting effect, strong adaptability, economy and environmental protection has been developed to further improve the quality of copper concentrate, which is of great significance to improving the economic benefits of enterprises, improving the utilization rate of mineral resources and protecting the ecological environment. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment. The method adopts a closed-circuit flotation test process of "one roughing, one concentrating, and one scavenging", uses an efficient and convenient solid combined inhibitor sodium percarbonate + sodium humate + sodium sulfite to suppress pyrite, and sequentially regulates the DO value, pH value and ORP value in the pulp. With butyl xanthate as a collector, it achieves efficient suppression of pyrite under high-altitude, low-dissolved oxygen and low-alkalinity conditions, obtains higher-quality copper-molybdenum concentrate, and effectively improves the economic benefits of mine development while protecting the high-altitude mine environment.

[0006] In order to achieve the above technical objectives, the present invention provides a method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment, comprising:

[0007] Step S1, grinding the mixed sulfur concentrate and kerosene, adding part of the adjusting agent 1# during the grinding process to obtain a concentrated ore pulp;

[0008] Step S2, after adding water to the concentrated slurry for slurry preparation, the remaining adjusting agent 1#, the inhibitor, the adjusting agent 2# and the frother are added in sequence to adjust the DO value of the slurry to 10-20 mg / L, the pH value to 9-11 and the OPR value to 150-200 mV, and then the frother is added for roughing;

[0009] Step S3, adding a collector to the tailings obtained from the roughing, and then scavenging to obtain scavenged tailings and sulfur tailings;

[0010] Step S4, adding an alkali agent to the concentrate obtained by roughing to adjust the pH value and then beneficiating to obtain copper-molybdenum concentrate and beneficiated middlings, and then combining the scavenged middlings and beneficiated middlings and returning to step S2 for a cyclic operation;

[0011] The low dissolved oxygen environment is a low dissolved oxygen environment with an altitude greater than 3400m.

[0012] Aiming at the problem that pyrite is difficult to inhibit in a low dissolved oxygen environment, the method of the present invention develops a new process of DO value-pH value-ORP value joint regulation of slurry to achieve efficient inhibition of pyrite; compared with the copper-lime high alkali sulfur inhibition process, the process flow is simple and easy to implement, has high sorting efficiency, and is safe and environmentally friendly. In the slurry solution environment, the DO value mainly controls the oxidative corrosion effect on the surface of pyrite. Too high DO value will lead to excessive corrosion, resulting in a decrease in the inhibition effect, while too low DO value will not be able to fully corrode and it is difficult to achieve flotation separation; pH value control keeps the slurry at an appropriate viscosity value to improve the inhibitor adsorption effect; ORP control prevents the addition of too much oxidant in the early stage of the process on the one hand, and on the other hand, it is also conducive to reducing the adsorption effect of the collector and improving the copper-sulfur separation effect; the order of reagent addition and slurry environmental parameters must follow this scheme. Changing any order and parameters will lead to problems such as decreased flotation efficiency, reduced concentrate quality, equipment circulation load, and increased energy consumption, affecting the ore dressing effect and economy.

[0013] As a preferred solution, the amount of kerosene added in step S1 is 5-20 g / t based on the dry weight of the mixed sulfur concentrate.

[0014] As a preferred solution, the fineness after grinding is 75-85% under a -325 mesh sieve.

[0015] As a preferred solution, the concentration of the concentrated slurry is 40-50%.

[0016] As a preferred solution, the adjusting agent 1# is solid percarbonate.

[0017] As a preferred solution, the inhibitor includes water glass and humate.

[0018] As a preferred solution, the adjusting agent includes 2#, including an alkali agent and solid anhydrous sulfite.

[0019] The solid percarbonate, humate and solid sulfite used in the present invention are safe, environmentally friendly, convenient to transport, simple, efficient and low-cost; among them, solid sodium percarbonate is mainly used to adjust the DO value of the pulp, humate can strengthen the inhibition of pyrite flotation in a low-alkali environment, and solid sulfite reduces the potential of the pulp and adjusts the OPR value of the pulp.

[0020] As a preferred solution, the solid percarbonate added in step S1 is 200-300 g / t based on the dry weight of the mixed sulfur concentrate.

[0021] The chemical reactions of solid sodium percarbonate in the slurry are mainly as follows:

[0022] 2Na2CO3·3H2O2=2Na2CO3+3H2O2

[0023] Na2CO3+H2O=NaHCO3+NaOH

[0024] Na2CO3+Ca 2+ =CaCO3(s)+2Na +

[0025] 2H + +H2O2+2Fe 2+ =2H2O+2Fe 3+ +O2(g)

[0026] Fe 3+ +3OH - =Fe(OH)3(s)

[0027] From the above chemical reaction formula, it can be seen that solid sodium percarbonate can not only enhance the surface oxidation of pyrite and promote the oxidation of divalent iron ions to trivalent iron ions, but also react with calcium ions in the ore pulp to precipitate and soften the water quality, thereby improving the sorting efficiency.

[0028] As a preferred solution, the process of adjusting the DO value, pH value and OPR value of the slurry in step S2 is: adding the remaining solid percarbonate to the slurry, aerating and stirring for 15 to 30 minutes, then adding water glass and humate, and then adding an alkali agent, a solid sulfite and a frother in sequence to obtain

[0029] The ore dressing environment targeted by the present invention is a low dissolved oxygen environment, which is the main reason for the difficulty in inhibiting pyrite. In order to enhance the oxidative corrosion of pyrite and strengthen the inhibition of pyrite, the present invention adds percarbonate in the early stage to decompose free oxygen and provide the dissolved oxygen environment required by the pulp. However, this also easily leads to an increase in the dissolved oxygen content in the pulp, which is beneficial to the adsorption of the collector and is not conducive to the inhibition of pyrite. Therefore, in order to control the adsorption effect of the collector, solid anhydrous sulfite needs to be added to adjust the pulp OPR value to improve the copper-sulfur separation effect.

[0030] As a preferred solution, the amount of solid percarbonate added in step S2 is 50-150 g / t based on the dry weight of the mixed sulfur concentrate.

[0031] As a preferred solution, the amount of water glass added is 75-125 g / t based on the dry weight of the mixed sulfur concentrate.

[0032] As a preferred solution, the amount of humate added is 50-100 g / t based on the dry weight of the mixed sulfur concentrate.

[0033] As a preferred solution, the amount of solid sulfite added is 80-120 g / t based on the dry weight of the mixed sulfur concentrate.

[0034] As a preferred solution, the alkali agent is at least one of sodium hydroxide, calcium hydroxide, sodium carbonate, sodium phosphate, sodium orthosilicate and sodium silicate.

[0035] As a preferred solution, when the alkaline agent is calcium hydroxide, the added amount thereof is 40-80 g / t based on the dry weight of the mixed sulfur concentrate.

[0036] As a preferred solution, the mass concentration of the concentrated slurry after adding water to the slurry is 18-25%.

[0037] As a preferred solution, the DO value of the slurry is 12-14 mg / L, the pH value is 9.8-10.5, and the OPR value is 160-190 mV.

[0038] As a preferred solution, the foaming agent is at least one of methyl isobutyl carbinol, sodium alkylbenzene sulfonate, sodium alkyl sulfate, polyethylene glycol ether and polyol ether.

[0039] As a preferred solution, when the foaming agent is methyl isobutyl carbinol, its added amount is 25-50 g / t based on the dry weight of the mixed sulfur concentrate.

[0040] As a preferred solution, the scavenging process is: adding butyl xanthate as a collector, the addition amount of which is 25-50 g / t based on the dry weight of the mixed sulfur concentrate, and then performing aeration flotation after sufficient stirring.

[0041] As a preferred solution, the selection process is: adding calcium hydroxide as an alkali agent, adjusting the pH of the system to 10.0-10.5, and performing aeration flotation after sufficient stirring.

[0042] It should be noted that the main purpose of the roughing stage is to ensure the recovery rate of the product, while the main purpose of the concentrating stage is to improve the grade of the concentrate. Therefore, a small amount of alkaline inhibitor will be appropriately added in the concentrating stage, resulting in a slight increase in the pH value.

[0043] Compared with the prior art, the beneficial technical effects of the technical solution of the present invention are:

[0044] 1) The method provided by the present invention is the first to address the problem that pyrite is difficult to inhibit in a high-altitude and low-dissolved oxygen environment. A combination of solid sodium percarbonate, sodium humate and sodium sulfite is used as a pyrite inhibitor. By jointly regulating DO value, pH value and ORP value, efficient separation of mixed sulfur concentrate under low alkalinity conditions in a high-altitude and low-dissolved oxygen environment is achieved. Compared with the traditional lime high-alkalinity (pH>12.0) sulfur inhibition flotation process, this process can greatly reduce the amount of alkali agent used, reduce pipeline blockage and corrosion, and reduce the calcification and stickiness of the pulp. It is safer, more environmentally friendly, more efficient and convenient.

[0045] 2) In the technical solution provided by the present invention, solid sodium percarbonate is used to regulate the DO value in the slurry to strengthen the surface oxidation of pyrite. Solid sodium percarbonate contains carbonate and is alkaline, and can replace part of the alkali agent to reduce its dosage; in addition, solid sodium percarbonate can also react with calcium ions in the slurry to generate calcium carbonate precipitation, soften water quality, and improve sorting efficiency. It can replace the safety and environmental protection, equipment corrosion and high transportation cost caused by strong oxidants such as hydrogen peroxide, hypochlorite and potassium permanganate.

[0046] 3) In the technical solution provided by the present invention, solid anhydrous sodium sulfite is used to regulate the ORP value of the slurry to consume excessive dissolved oxygen, reduce the slurry potential, and further reduce the adsorption of the collector on the surface of pyrite to reduce the floatability of pyrite. Through the closed-circuit flotation process of "one roughing selection, one scavenging selection, and one concentrating selection", a copper (molybdenum) concentrate with a copper content of 25.97%, a molybdenum content of 0.65%, and a copper recovery rate of 93.9% is obtained. Excellent indicators, which can provide reference and demonstration for the efficient and green separation of sulfide copper ores in high-altitude areas at home and abroad. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of the method provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that all cases are carried out in a high-altitude, low-dissolved oxygen environment (altitude 3400m, DO=4.5mg / L). This embodiment is improved on the basis of the comparative example, and based on the technical solution, a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to this embodiment.

[0049] Comparative Example 1

[0050] In a high-altitude area of ​​Yunnan (3400m above sea level), a mixed sulfide concentrate sample was obtained by roughing with mixed flotation process. The copper grade in the mixed sulfide concentrate was 4.43% and the molybdenum grade was 0.10%. In order to obtain copper (molybdenum) concentrate that meets market needs, the closed-circuit flotation process of "one roughing, one scavenging, and one concentrating" was used to separate the gangue and pyrite. Figure 1 As shown, the specific steps include:

[0051] S1. Grinding operation: Based on the dry weight of each ton of mixed sulfur concentrate, 5-20g / t of kerosene is added to the mixed sulfur concentrate for slurry adjustment before grinding to maintain the flotation effect of molybdenite. During the grinding operation, 1000-1500g / t of lime is added to the slurry, and the slurry grinding mass concentration is maintained at 40-50%;

[0052] S2. Slurry adjustment: according to the dry weight of each ton of mixed sulfur concentrate, water is added to the mixed sulfur concentrate slurry for slurry adjustment, and the slurry mass concentration is maintained at 18-25%; 75-125g / t of water glass is added to disperse the gangue minerals, and the slurry is stirred for 2 minutes; 120-240g / t of lime is added to adjust the pH value of the slurry to 12.0-12.4 to strengthen the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes;

[0053] S3, roughing operation: according to the dry weight of each ton of mixed sulfur concentrate, add 5-20g / t of MIBC flotation frother to the pulp after the pulping operation, and stir the pulp for 1 minute; after stirring, start aeration for flotation, the obtained concentrate enters the concentration operation, and the obtained tailings enter the scavenging operation;

[0054] S4, scavenging operation: according to the dry weight of each ton of mixed sulfur concentrate, 25-50g / t of butyl xanthate is added to the tailings obtained in step S3 as a flotation collector for copper (molybdenum) minerals, and the slurry is stirred for 2 minutes; after stirring, aeration is started for flotation, and the obtained concentrate is the scavenged ore, and the obtained tailings are the final sulfur tailings;

[0055] S5, beneficiation operation: based on the dry weight of each ton of mixed sulfur concentrate, 50-100g / t of lime is added to the concentrate obtained in step S3 as a pyrite flotation inhibitor, and the pH value of the slurry is controlled at 12.0-12.4; after the slurry is stirred for 3 minutes, aeration is started for flotation, and the obtained concentrate is the final copper (molybdenum) concentrate, and the obtained tailings are the beneficiated middlings;

[0056] S6, middling ore return operation: the selected middling ore obtained in step S5 and the scavenged middling ore obtained in step S4 are combined and returned to the slurry mixing operation in step S2 to continue the closed-loop circulation operation.

[0057] Comparative Example 2

[0058] In a high-altitude area of ​​Yunnan (3400m above sea level), a mixed sulfide concentrate sample was obtained by roughing with mixed flotation process. The copper grade in the mixed sulfide concentrate was 4.44% and the molybdenum grade was 0.11%. In order to obtain copper (molybdenum) concentrate that meets market needs, the closed-circuit flotation process of "one roughing, one scavenging, and one concentrating" was used to separate the gangue and pyrite. Figure 1 As shown, the specific steps include:

[0059] S1. Grinding operation: Based on the dry weight of each ton of mixed sulfur concentrate, 5-20g / t of kerosene is added to the mixed sulfur concentrate for slurry adjustment before grinding to maintain the flotation effect of molybdenite. During the grinding operation, 200-400g / t of lime is added to the slurry, and the slurry grinding mass concentration is maintained at 40-50%;

[0060] S2. Slurry adjustment: according to the dry weight of each ton of mixed sulfur concentrate, water is added to the mixed sulfur concentrate slurry for slurry adjustment, and the slurry mass concentration is maintained at 18-25%; 50-100g / t of lime is added to adjust the slurry pH value to 9.8-10.5 to strengthen the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes; 75-125g / t of water glass is added to disperse the gangue minerals, and 50-100g / t of sodium humate is added to strengthen the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes;

[0061] S3, roughing operation: according to the dry weight of each ton of mixed sulfur concentrate, add 5-20g / t of MIBC flotation frother to the pulp after the pulping operation, and stir the pulp for 1 minute; after stirring, start aeration for flotation, the obtained concentrate enters the concentration operation, and the obtained tailings enter the scavenging operation;

[0062] S4, scavenging operation: according to the dry weight of each ton of mixed sulfur concentrate, 25-50g / t of butyl xanthate is added to the tailings obtained in step S3 as a flotation collector for copper (molybdenum) minerals, and the slurry is stirred for 2 minutes; after stirring, aeration is started for flotation, and the obtained concentrate is the scavenged ore, and the obtained tailings are the final sulfur tailings;

[0063] S5, beneficiation operation: based on the dry weight of each ton of mixed sulfur concentrate, 10-25g / t of lime is added to the concentrate obtained in step S3 as a pyrite flotation inhibitor, and the pH value of the slurry is controlled at 10.0-10.5; after the slurry is stirred for 3 minutes, aeration is started for flotation, and the obtained concentrate is the final copper (molybdenum) concentrate, and the obtained tailings are the beneficiated middlings;

[0064] S6, middling ore return operation: the selected middling ore obtained in step S5 and the scavenged middling ore obtained in step S4 are combined and returned to the slurry mixing operation in step S2 to continue the closed-loop circulation operation.

[0065] Example 1

[0066] In a high-altitude area in Yunnan (3400m above sea level), a mixed sulfide concentrate sample was obtained by roughing with mixed flotation process. The copper grade in the mixed sulfide concentrate was 4.41% and the molybdenum grade was 0.11%. In order to obtain copper (molybdenum) concentrate that meets market needs, a closed-circuit flotation process of "one roughing, one scavenging, and one concentrating" was used to separate the gangue and pyrite. Figure 1 As shown, the specific steps include:

[0067] S1. Grinding operation: Based on the dry weight of each ton of mixed sulfur concentrate, 5-20g / t of kerosene is added to the mixed sulfur concentrate for slurry adjustment before grinding to maintain the flotation effect of molybdenite. During the grinding operation, 200-300g / t of solid sodium percarbonate is added to the slurry, and the slurry grinding mass concentration is maintained at 40-50%;

[0068] S2. Slurry adjustment: according to the dry weight of each ton of mixed sulfur concentrate, water is added to the mixed sulfur concentrate slurry for slurry adjustment, and the slurry mass concentration is maintained at 18-25%; 50-150g / t of solid sodium percarbonate is added again to the DO value to 12-14mg / L, and the slurry is stirred and aerated for 20min; 75-125g / t of water glass is added to disperse the gangue minerals, and 50-100g / t of sodium humate is added to strengthen the inhibition of pyrite flotation, and the slurry is stirred for 2min; 40-80g / t of lime is added to adjust the slurry pH value to 9.8-10.5 to strengthen the inhibition of pyrite flotation, and the slurry is stirred for 2min; finally, 80-120g / t of solid sodium sulfite is added to reduce the slurry potential, and the slurry ORP value is adjusted to 160-190mV (VS.Ag / AgCl), and the slurry is stirred for 2min;

[0069] S3, roughing operation: according to the dry weight of each ton of mixed sulfur concentrate, add 5-20g / t of MIBC flotation frother to the pulp after the pulping operation, and stir the pulp for 1 minute; after stirring, start aeration for flotation, the obtained concentrate enters the concentration operation, and the obtained tailings enter the scavenging operation;

[0070] S4, scavenging operation: according to the dry weight of each ton of mixed sulfur concentrate, 25-50g / t of butyl xanthate is added to the tailings obtained in step S3 as a flotation collector for copper (molybdenum) minerals, and the slurry is stirred for 2 minutes; after stirring, aeration is started for flotation, and the obtained concentrate is the scavenged ore, and the obtained tailings are the final sulfur tailings;

[0071] S5, beneficiation operation: based on the dry weight of each ton of mixed sulfur concentrate, 10-25g / t of lime is added to the concentrate obtained in step S3 as a pyrite flotation inhibitor, and the pH value of the slurry is controlled at 10.0-10.5; after the slurry is stirred for 3 minutes, aeration is started for flotation, and the obtained concentrate is the final copper (molybdenum) concentrate, and the obtained tailings are the beneficiated middlings;

[0072] S6, middling ore return operation: the selected middling ore obtained in step S5 and the scavenged middling ore obtained in step S4 are combined and returned to the slurry mixing operation in step S2 to continue the closed-loop circulation operation.

[0073] The process indicators of the comparative example and the embodiment are shown in Table 1. The results of the embodiment show that the copper (molybdenum) concentrate grade of the mixed sulfur concentrate after flotation treatment is significantly improved by using this method, and the copper and molybdenum grades of the concentrate reach 25.97% and 0.65% respectively, and the recovery rates of copper and molybdenum in the concentrate reach 93.9% and 91.1% respectively. It not only realizes the effective recovery of copper and molybdenum metals, but also greatly improves the quality of the concentrate, and the copper-sulfur separation effect is greatly improved.

[0074]

Claims

1. A method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment, characterized in that: include: Step S1, grinding the mixed sulfur concentrate and kerosene, adding part of the adjusting agent 1# during the grinding process to obtain a concentrated ore pulp; Step S2, after adding water to the concentrated slurry for slurry preparation, the remaining adjusting agent 1#, the inhibitor, the adjusting agent 2# and the frother are added in sequence to adjust the DO value of the slurry to 10-20 mg / L, the pH value to 9-11 and the OPR value to 150-200 mV, and then the frother is added for roughing; Step S3, adding a collector to the tailings obtained from the roughing, and then scavenging to obtain scavenged tailings and sulfur tailings; Step S4, adding an alkali agent to the concentrate obtained by roughing to adjust the pH value and then beneficiating to obtain copper-molybdenum concentrate and beneficiated middlings, and then combining the scavenged middlings and beneficiated middlings and returning to step S2 for a cyclic operation; The low dissolved oxygen environment is a low dissolved oxygen environment with an altitude greater than 3400m.

2. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 1, characterized in that: The amount of kerosene added in step S1 is 5-20 g / t based on the dry weight of the mixed sulfur concentrate; the fineness after grinding is 75-85% under a -325 mesh sieve; and the concentration of the concentrated slurry is 40-50%.

3. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 1, characterized in that: The adjusting agent 1# is solid percarbonate; the inhibitor includes water glass and humate; and the adjusting agent 2# includes an alkali agent and solid anhydrous sulfite.

4. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 3, characterized in that: The solid percarbonate added in step S1 is 200-300 g / t based on the dry weight of the mixed sulfur concentrate.

5. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 3, characterized in that: The process of adjusting the DO value, pH value and OPR value of the slurry in step S2 is: adding the remaining solid percarbonate to the slurry, aerating and stirring for 15 to 30 minutes, then adding water glass and humate, and then adding alkali agent, solid sulfite and foaming agent in sequence.

6. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 3, characterized in that: In the step S2, the amount of solid percarbonate added is 50-150 g / t based on the dry weight of the mixed sulfur concentrate; the amount of water glass added is 75-125 g / t based on the dry weight of the mixed sulfur concentrate; the amount of humate added is 50-100 g / t based on the dry weight of the mixed sulfur concentrate; and the amount of solid sulfite added is 80-120 g / t based on the dry weight of the mixed sulfur concentrate.

7. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 5, characterized in that: The alkali agent is at least one of sodium hydroxide, calcium hydroxide, sodium carbonate, sodium phosphate, sodium orthosilicate and sodium silicate; when the alkali agent is calcium hydroxide, its addition amount is 40-80g / t based on the dry weight of the mixed sulfur concentrate.

8. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 1, characterized in that: The mass concentration of the concentrated slurry after adding water to the slurry is 18-25%; the DO value of the slurry is 12-14 mg / L, the pH value is 9.8-10.5, and the OPR value is 160-190 mV.

9. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 1, characterized in that: The foaming agent is at least one of methyl isobutyl carbinol, sodium alkylbenzene sulfonate, sodium alkyl sulfate, polyethylene glycol ether and polyol ether; when the foaming agent is methyl isobutyl carbinol, its addition amount is 25-50g / t based on the dry weight of the mixed sulfur concentrate.

10. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 1, characterized in that: The scavenging process is as follows: adding butyl xanthate as a collector, the addition amount of which is 25-50 g / t based on the dry weight of the mixed sulfur concentrate, and then fully stirring and then performing aeration flotation; the selection process is as follows: adding calcium hydroxide as an alkali agent, adjusting the pH of the system to 10.0-10.5, and then fully stirring and then performing aeration flotation.

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