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

Abstract

The present invention discloses a method for sulfur-inhibiting flotation of mixed sulfur concentrate in a low dissolved oxygen environment. The method comprises: grinding the mixed sulfur concentrate with kerosene, adding part of the inhibitor during the grinding process to obtain a concentrated slurry; adding water to the concentrated slurry for slurry adjustment, sequentially adding the remaining inhibitor and alkaline agent to adjust the DO value, pH value and OPR value of the slurry, and then adding a frother for roughing; adding a collector to the tailings obtained from the roughing to scavenge and obtain scavenged ore and sulfur tailings; adding an alkaline agent to the concentrate obtained from the roughing to adjust the pH value again and then concentrating to obtain copper-molybdenum concentrate and concentrating middlings, and then combining the scavenged ore and the concentrating middlings and returning them to the slurry adjustment process for a cyclic operation. The method inhibits pyrite flotation by jointly regulating the DO value, pH value and ORP value, achieves efficient pyrite inhibition under high-altitude, low-dissolved oxygen and low-alkalinity conditions, significantly improves the grade of copper-molybdenum concentrate, and effectively improves the economic benefits of mine development while protecting the high-altitude mine environment.

Description

Technical Field

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

[0002] Copper, known as the king of non-ferrous metals, is widely used in the electrical industry. With the development of new energy and artificial intelligence, the demand for copper resources is increasing. High-altitude copper sulfide deposits are attracting increasing attention due to their polymetallic content and vast reserves. However, mine development is challenging due to the low oxygen and pressure environments and transportation difficulties at high altitudes. Sulfide minerals in high-altitude copper mines are primarily chalcopyrite and pyrite. Chalcopyrite is naturally more hydrophobic than pyrite, making it more susceptible to collector adsorption and exhibiting better floatability. Therefore, separation flotation processes typically focus on suppressing pyrite. However, due to the lower air pressure at high altitudes, the dissolved oxygen (DO) in the slurry is relatively low, which can affect mineral interfaces. Previous studies have shown that the low DO environment at high altitudes reduces the formation of hydroxylation on the pyrite surface and produces more hydrophobic sulfur. The reduction in hydroxylation also provides more adsorption sites for collectors, which increases adsorption capacity and enhances the hydrophobicity of pyrite. The low dissolved oxygen environment at high altitudes has been shown to be beneficial for 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 the purpose of separation. Theoretically, the adsorption of collectors on the surface of sulfide ores is an electrochemical process that can be controlled by adjusting the pulp 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 precipitates of ferrous hydroxide and ferric hydroxide on the surface of pyrite. Ca 2+Surface reactions generate hydrophilic, insoluble substances such as CaSO4, which reduce the adsorption of collectors and thus inhibit pyrite. Lime is usually added in the form of lime milk. Due to its low solubility, it can easily cause pipeline blockage and equipment corrosion. Lime also calcifies the slurry, making the foam sticky and less fluid, and easily entraining gangue minerals, resulting in reduced sorting performance. Large amounts of lime lead to poor recovery of associated rare metals, reducing overall economic benefits. Transportation to high altitudes is difficult, and large amounts of lime not only increase transportation costs but also pollute the environment. Therefore, most research focuses on the development of low-alkali, high-efficiency, and green sulfur suppression 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 the participation of appropriate dissolved oxygen. It seems that controlling the pH of the slurry alone is not enough, and the use of oxidation methods in combination with organic inhibitors seems more feasible. 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 order to solve 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 response to the problems existing in the prior art, the present invention aims to provide a sulfur suppression flotation method for mixed sulfur concentrate in a low dissolved oxygen environment. This method uses a closed-circuit flotation test process of "one roughing, one cleaning, and one scavenging" to suppress pyrite using a highly efficient and convenient solid combined inhibitor of sodium percarbonate, sodium humate, and sodium sulfite. The DO, pH, and ORP values ​​in the ore pulp are sequentially regulated, and butyl xanthate is used as a collector. This method achieves efficient pyrite suppression under high-altitude, low-dissolved-oxygen, and low-alkalinity conditions, resulting in higher-quality copper-molybdenum concentrates. This method effectively improves the economic benefits of mine development while protecting the high-altitude mining 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 a portion of the adjusting agent 1# during the grinding process to obtain a concentrated ore pulp;

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

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

[0010] Step S4: adding an alkaline agent to the concentrate obtained from the 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 them to step S2 for a cyclic operation;

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

[0012] The method of the present invention aims to solve the problem of pyrite being difficult to inhibit in a low dissolved oxygen environment, and develops a new process for jointly regulating the pulp by the DO value, pH value, and ORP value, thereby achieving 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 pulp solution environment, the DO value mainly controls the oxidative corrosion effect on the surface of pyrite. A too high DO value will lead to excessive corrosion, resulting in a decrease in the inhibition effect, while a too low DO value will not be able to corrode sufficiently, making it difficult to achieve flotation separation. pH value control enables the pulp to maintain an appropriate viscosity value, thereby improving the adsorption effect of the inhibitor. ORP control prevents the addition of too much oxidant in the early stage of the process, and on the other hand, it is also beneficial to reduce the adsorption effect of the collector and improve the copper-sulfur separation effect. The order of reagent addition and the pulp environmental parameters must follow this scheme. Changing any order and parameters will lead to problems such as decreased flotation efficiency, reduced concentrate quality, increased equipment circulation load, and increased energy consumption, thereby affecting the mineral processing 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, easy to transport, simple, efficient and low-cost. Among them, solid sodium percarbonate is mainly used to adjust the DO value of the ore pulp, humate can enhance the inhibition of pyrite flotation in a low-alkali environment, and solid sulfite reduces the ore pulp potential and adjusts the OPR value of the ore 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 as follows: 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, solid sulfite and a foaming agent 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 slurry. However, this also easily leads to an increase in the dissolved oxygen content in the slurry, 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 regulate the slurry 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 addition amount of the humate 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 slurrying with water 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 as follows: butyl xanthate is added as a collector in an amount of 25-50 g / t based on the dry weight of the mixed sulfur concentrate, and then aeration flotation is performed 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 addresses for the first time the problem of pyrite being difficult to suppress in high-altitude, low-dissolved-oxygen environments. A combination of solid sodium percarbonate, sodium humate, and sodium sulfite is used as pyrite inhibitors. By jointly regulating DO, pH, and ORP values, efficient separation of mixed sulfur concentrates under low alkalinity conditions at high altitudes and low dissolved oxygen levels is achieved. Compared with the traditional lime high-alkalinity (pH>12.0) sulfur suppression flotation process, this process can significantly reduce the amount of alkali used, reduce pipeline blockage and corrosion, and reduce calcification and stickiness of the pulp, making it safer, more environmentally friendly, more efficient, and more 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 enhance the surface oxidation of pyrite. Solid sodium percarbonate contains carbonate and is alkaline, which can replace part of the alkaline agent to reduce its usage. In addition, solid sodium percarbonate can also react with calcium ions in the slurry to form calcium carbonate precipitate, softening water quality and improving sorting efficiency. It can replace the safety and environmental protection, equipment corrosion and high transportation cost problems 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 excess dissolved oxygen, reduce the slurry potential, and further reduce the adsorption of the collector on the surface of pyrite, thereby reducing the floatability of pyrite. Through a closed-circuit flotation process of "one roughing, one scavenging, and one cleaning", 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, this can provide reference and demonstration for the efficient and green separation of copper sulfide 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 with reference to the accompanying drawings. It should be noted that all cases were 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 is based on the present technical solution. A detailed implementation method and specific operating process are given, but the scope of protection 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 copper (molybdenum) sulfide ore mixed flotation process. The copper grade of the mixed sulfide concentrate was 4.43% and the molybdenum grade was 0.10%. In order to obtain copper (molybdenum) concentrate that meets market demand, 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:

[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 before grinding to adjust the slurry 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: Based on the dry weight of each ton of mixed sulfur concentrate, water is added to the mixed sulfur concentrate slurry to adjust the slurry, 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 slurry pH to 12.0-12.4 to enhance the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes;

[0053] S3, roughing operation: Based on the dry weight of each ton of mixed sulfur concentrate, 5-20g / t of MIBC flotation frother is added to the slurry after the slurry adjustment operation, and the slurry is stirred for 1 minute. After stirring, aeration is started for flotation. The resulting concentrate enters the cleaning operation, and the resulting tailings enter the scavenging operation;

[0054] S4, scavenging operation: based on the dry weight of the 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 resulting concentrate is the scavenged ore, and the resulting tailings are the final sulfur tailings;

[0055] S5, beneficiation operation: based on the dry weight of the 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. The resulting concentrate is the final copper (molybdenum) concentrate, and the resulting 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-circuit 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 copper (molybdenum) sulfide ore 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 demand, 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:

[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 before grinding to adjust the slurry 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: Based on 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 to 9.8-10.5 to enhance 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 enhance the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes;

[0061] S3, roughing operation: Based on the dry weight of each ton of mixed sulfur concentrate, 5-20g / t of MIBC flotation frother is added to the slurry after the slurry adjustment operation, and the slurry is stirred for 1 minute. After stirring, aeration is started for flotation. The resulting concentrate enters the cleaning operation, and the resulting tailings enter the scavenging operation;

[0062] S4, scavenging operation: based on the dry weight of the 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 resulting concentrate is the scavenged ore, and the resulting tailings are the final sulfur tailings;

[0063] S5, beneficiation operation: based on the dry weight of the mixed sulfur concentrate, 10-25g / t of lime is added to the concentrate obtained in step S3 as a pyrite flotation depressant, and the pH value of the slurry is controlled at 10.0-10.5; after stirring the slurry for 3 minutes, aeration is started for flotation. The resulting concentrate is the final copper (molybdenum) concentrate, and the resulting 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-circuit circulation operation.

[0065] Example 1

[0066] In a high altitude area of ​​Yunnan (3400m above sea level), a mixed sulfide concentrate sample was obtained by roughing copper (molybdenum) sulfide ore mixed flotation process. The copper grade of the mixed sulfide concentrate was 4.41% and the molybdenum grade was 0.11%. In order to obtain copper (molybdenum) concentrate that meets market demand, a closed-circuit flotation process of "one roughing, one scavenging, and one concentrating" was adopted 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 before grinding to adjust the slurry 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: Based on the dry weight of each ton of mixed sulfur concentrate, water is added to the mixed sulfur concentrate slurry to adjust the slurry, and the slurry mass concentration is maintained at 18-25%; 50-150g / t of solid sodium percarbonate is added again to increase the DO value to 12-14mg / L, and the slurry is stirred and aerated for 20 minutes; 75-125g / t of water glass is added to disperse the gangue minerals, and 50-100g / t of sodium humate is added to enhance the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes; 40-80g / t of lime is added to adjust the slurry pH to 9.8-10.5 to enhance the inhibition of pyrite flotation, and the slurry is stirred for 2 minutes; finally, 80-120g / t of solid sodium sulfite is added to reduce the slurry potential and adjust the slurry ORP value to 160-190mV (VS.Ag / AgCl), and the slurry is stirred for 2 minutes;

[0069] S3, roughing operation: Based on the dry weight of each ton of mixed sulfur concentrate, 5-20g / t of MIBC flotation frother is added to the slurry after the slurry adjustment operation, and the slurry is stirred for 1 minute. After stirring, aeration is started for flotation. The resulting concentrate enters the cleaning operation, and the resulting tailings enter the scavenging operation;

[0070] S4, scavenging operation: based on the dry weight of the 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 resulting concentrate is the scavenged ore, and the resulting tailings are the final sulfur tailings;

[0071] S5, beneficiation operation: based on the dry weight of the mixed sulfur concentrate, 10-25g / t of lime is added to the concentrate obtained in step S3 as a pyrite flotation depressant, and the pH value of the slurry is controlled at 10.0-10.5; after stirring the slurry for 3 minutes, aeration is started for flotation. The resulting concentrate is the final copper (molybdenum) concentrate, and the resulting 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-circuit circulation operation.

[0073] The process parameters for the comparative example and the example are shown in Table 1. The results of the example demonstrate that using this method, the copper (molybdenum) concentrate grade of the mixed sulfur concentrate after flotation treatment is significantly improved, with the concentrate copper and molybdenum grades reaching 25.97% and 0.65%, respectively, and the concentrate copper and molybdenum recoveries reaching 93.9% and 91.1%, respectively. This method not only effectively recovers copper and molybdenum metals, but also significantly improves concentrate quality and significantly enhances copper and sulfur separation efficiency.

[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 a portion of the adjusting agent 1# during the grinding process to obtain a concentrated slurry; Step S2: After adding water to the concentrated ore pulp for slurry preparation, the remaining adjusting agent 1#, the inhibitor, the adjusting agent 2#, and the foaming agent are sequentially added to adjust the DO value of the ore pulp to 10-20 mg / L, the pH value to 9-11, and the ORP value to 150-200 mV, and then the foaming agent is added for roughing; Step S3, adding a collector to the tailings obtained from the roughing, and then scavenging to obtain scavenged ore and sulfur tailings; Step S4: adding an alkaline agent to the concentrate obtained from the 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 them to step S2 for a cyclic operation; The low dissolved oxygen environment is a low dissolved oxygen environment at an altitude of >3400m; 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 of the ore after grinding is 75-85% below the -325 mesh sieve; the concentration of the concentrated slurry is 40-50%; The adjusting agent 1# is solid percarbonate; the inhibitor includes water glass and humate; the adjusting agent 2# includes an alkali agent and solid anhydrous sulfite; The solid percarbonate added in step S1 is 200-300 g / t based on the dry weight of the mixed sulfur concentrate; In 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.

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 process of adjusting the DO value, pH value and ORP value of the slurry in step S2 is as follows: 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, solid sulfite and a foaming agent in sequence.

3. The method for sulfur suppression flotation of mixed sulfur concentrate in a low dissolved oxygen environment according to claim 2, 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.

4. 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 slurrying with water is 18-25%; the DO value of the slurry is 12-14 mg / L, the pH value is 9.8-10.5, and the ORP value is 160-190 mV.

5. 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, and polyethylene glycol ether; when the foaming agent is methyl isobutyl carbinol, its addition amount is 25-50 g / t based on the dry weight of the mixed sulfur concentrate.

6. 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 includes: adding butyl xanthate as a collector in an amount of 25-50 g / t based on the dry weight of the mixed sulfur concentrate, stirring thoroughly and then performing aeration flotation; the selecting process includes: adding calcium hydroxide as an alkali agent, adjusting the pH of the system to 10.0-10.5, stirring thoroughly and then performing aeration flotation.

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