Flotation method for high-sulfur copper ore containing mud

Abstract

This invention provides a flotation method for high-sulfur, muddy copper ore. First, the ore to be processed is pre-screened and classified. Then, only the larger particles are ground to reduce mud formation during grinding. Next, a copper-preferential process is performed. A pyrite composite depressant is obtained by compounding lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in a specific ratio. Utilizing the bonding between inorganic and organic matter and the synergistic effect of the substances in the pyrite composite depressant, pyrite is suppressed to the greatest extent, achieving efficient separation of copper and pyrite. Simultaneously, middlings are mixed and regrinded instead of being directly returned to the previous process. This middlings mixing and regrinding, combined with the use of the pyrite composite depressant, enhances the efficient separation of copper and pyrite. Finally, under the action of an activator, a pyrite collector, and a frother, efficient sulfur separation is achieved, ultimately yielding two qualified products: copper concentrate and sulfur concentrate.

Description

Technical Field

[0001] This invention relates to the field of mineral processing and metallurgy, and in particular to a flotation method for high-sulfur copper ore containing mud. Background Technology

[0002] Copper metal, due to its good ductility, thermal conductivity, electrical conductivity, and wear resistance, is widely used in electrical, mechanical manufacturing, construction, and light industries. More than 80% of the world's copper metal is obtained through the smelting of copper sulfides. Pyrite is the most common associated mineral in copper sulfide ore. Because copper sulfide ore and pyrite have similar floatability, copper sulfide ore often accumulates alongside pyrite during flotation, severely affecting the quality of copper concentrate and leading to a sharp increase in downstream copper smelting costs.

[0003] Lime is a good depressant for pyrite, and it is also inexpensive. Currently, in the copper-sulfur flotation separation process of high-sulfur copper ores, lime is commonly used to suppress the floatability of pyrite in a high-alkali environment. Although it has a certain effect, the use of large amounts of lime will cause serious scaling of pipelines, pipeline blockage, equipment corrosion, increased cost of downstream pyrite flotation, and increased wastewater treatment costs.

[0004] With the rapid development of low-alkali processing technology, some composite pyrite inhibitors have been continuously developed and researched. Patent application number CN201810548647.6 discloses a composite pyrite inhibitor and its application. This composite pyrite inhibitor is composed of two or more of sodium dimethyl dithiocarbamate, sodium thiosulfate, disodium ethylenediaminetetraacetate, and sodium sulfite, and is used in lead-sulfur separation processes under a high-alkali slurry environment with a pH of 12. Although this inhibitor has a certain inhibitory effect on pyrite, its flotation effect needs to be improved when applied to the beneficiation process of clayey, high-sulfur copper sulfide ores due to the high similarity in floatability between copper sulfide and pyrite, and the interference of clayey gangue on flotation.

[0005] In view of this, it is necessary to design an improved flotation method for high-sulfur, muddy copper ores to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a flotation method for high-sulfur, muddy copper ore. First, the minerals to be processed are pre-screened and classified. Then, a copper-preferential separation process is performed. A pyrite composite depressant is obtained by compounding lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in a specific ratio. Utilizing the synergistic effect of the substances in the pyrite composite depressant, pyrite is suppressed to the greatest extent, achieving efficient separation of copper and pyrite. Simultaneously, the middlings are mixed, regrinded, and further separated to enhance the efficient separation of copper and pyrite. Finally, with the action of an activator, a pyrite collector, and a frother, sulfur is efficiently recovered, ultimately yielding two qualified products: copper concentrate and sulfur concentrate.

[0007] To achieve the above-mentioned objective, this invention provides a flotation method for high-sulfur, muddy copper ore, comprising the following steps:

[0008] S1. The raw ore to be selected is pre-screened and classified, and the ore on the screen is ball-milled to a predetermined fineness and mixed with the ore under the screen to prepare a slurry of a predetermined concentration;

[0009] S2. The slurry obtained in step S1 is subjected to two copper roughing processes to obtain rough copper concentrate and rough copper middlings; the obtained rough copper concentrate is then subjected to two copper cleaning processes to obtain copper concentrate, and the rough copper middlings are subjected to three copper scavenging processes to obtain copper tailings.

[0010] The middlings from the first copper beneficiation of the rough copper concentrate, the concentrate from the first copper scavenging of the rough copper middlings, and the concentrate from the second copper scavenging of the rough copper middlings are mixed and regrinded, and then subjected to two copper scavenging processes to obtain copper scavenged concentrate and copper scavenged tailings.

[0011] Pyrite composite inhibitors are added during the copper roughing, copper cleaning, copper scavenging, and copper concentrate scavenging processes. The pyrite composite inhibitors are composed of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid.

[0012] S3. Perform a first sulfur roughing process on the copper tailings obtained in step S2 to obtain rough sulfur concentrate and rough sulfur middlings; combine the rough sulfur concentrate and the copper concentrate scavenging tailings obtained in step S2 and perform two sulfur cleaning processes to obtain sulfur concentrate; perform two sulfur scavenging processes on the rough sulfur middlings to obtain tailings.

[0013] As a further improvement of the present invention, in step S2, the mass ratio of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide and citric acid in the pyrite composite inhibitor is (2-4):(1-3):(1-3):(1-3):(0.5-2).

[0014] As a further improvement of the present invention, in step S1, the pre-screening and grading is to grind the ore with a particle size greater than 0.045 mm using a standard sieve of 0.045 mm; after grinding, it is mixed with the ore undersize to prepare a slurry with a mass concentration of 30% to 45%, wherein the ore with a particle size less than 0.074 mm accounts for 50% to 90% of the slurry.

[0015] As a further improvement of the present invention, in step S2, in the two copper roughing processes, the amount of pyrite composite inhibitor used in the first copper roughing process is 500-7000 g / t, the amount of copper collector is 10-150 g / t, and the amount of frother is 10-50 g / t; in the second copper roughing process, the amount of pyrite composite inhibitor used is 0-1000 g / t, and the amount of copper collector is 5-100 g / t.

[0016] In the two copper beneficiation processes, the dosage of pyrite compound inhibitor was 50–2000 g / t in the first copper beneficiation process and 0–1000 g / t in the second copper beneficiation process.

[0017] In the three copper scavenging processes, the dosage of pyrite compound inhibitor was 0–2000 g / t in the first scavenging process and 0–60 g / t in the copper collector; in the second scavenging process, the dosage of pyrite compound inhibitor was 0–1500 g / t and 0–40 g / t in the copper collector; and in the third scavenging process, the dosage of pyrite compound inhibitor was 0–1000 g / t and 0–20 g / t in the copper collector.

[0018] As a further improvement of the present invention, in step S2, the copper collector is one or more of ethyl thiocyanate, ester 105, ethyl xanthate, isopropyl xanthate and butyl ammonium black powder; the foaming agent is one of methyl isobutyl methanol and hexanol methyl pentanol.

[0019] As a further improvement of the present invention, in step S2, the middlings from the first copper beneficiation, the concentrate from the first copper scavenging, and the concentrate from the second copper scavenging are mixed and regrinded to obtain a regrinding slurry with a mass concentration of 5% to 20%; the ore with a particle size of less than 0.038 mm accounts for 50% to 90% of the regrinding slurry.

[0020] As a further improvement of the present invention, in the two copper scavenging processes, the dosage of pyrite composite inhibitor in the first copper scavenging process is 0-2000 g / t, and the dosage of copper collector is 5-50 g / t; in the second copper scavenging process, the dosage of pyrite composite inhibitor is 0-1000 g / t, and the dosage of copper collector is 0-40 g / t.

[0021] As a further improvement of the present invention, in step S3, during the crude selection of sulfur, an activator, a pyrite collector, and a foaming agent are added.

[0022] As a further improvement of the present invention, the activator is copper sulfate; the pyrite collector is one or more of isoamyl xanthate, butyl xanthate and isopropyl xanthate; and the foaming agent is pine oil.

[0023] As a further improvement of the present invention, in step S2, the concentrate from the first copper roughing, the concentrate from the second copper roughing, the concentrate from the first copper scavenging, and the tailings from the second copper cleaning are mixed and then enter the first copper cleaning operation; the tailings from the second copper scavenging, the concentrate from the first sulfur roughing, and the tailings from the second sulfur cleaning are mixed and then enter the first sulfur cleaning operation.

[0024] The beneficial effects of this invention are:

[0025] (1) The flotation method for high-sulfur, muddy copper ore provided by this invention, based on the characteristics of high-muddy minerals, firstly pre-screens and classifies the minerals to be beneficiated, and then grinds only the larger-sized ores to reduce mud formation during grinding. Next, a copper-selective beneficiation process is carried out. During copper beneficiation, a pyrite composite inhibitor is obtained by compounding lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in a specific ratio. Utilizing the mutual bonding between inorganic and organic matter, and with the synergistic effect of the substances in the pyrite composite inhibitor, a dense hydrophilic film is formed on the surface of pyrite, maximizing the inhibition of pyrite and achieving efficient separation of copper and pyrite. Simultaneously, scavenged copper concentrate I, scavenged copper concentrate II, and refined copper middlings I are mixed and regrinded instead of being directly returned to the previous process. By regrinding the mixed middlings to a suitable fineness and preparing a suitable regrinding slurry concentration, combined with the use of the pyrite composite inhibitor, the efficient separation of copper and pyrite is enhanced. Finally, with the help of activators, pyrite collectors, and frothers, sulfur is efficiently recovered, resulting in two qualified products: copper concentrate and sulfur concentrate. This process demonstrates good copper-sulfur separation performance and strong adaptability to different ores, effectively solving the problem of separation under low-alkali conditions in muddy, high-sulfur copper ore resources. It provides a new and effective method for the development and utilization of similar muddy, high-sulfur copper ore resources.

[0026] (2) Under the low-alkali conditions of slurry environment with pH value of 7 to 9, the present invention achieves efficient separation of chalcopyrite and pyrite through a preferential copper separation process of two roughing, three scavenging, two cleaning and two fine scavenging processes and mixed middlings regrinding. The tailings after the preferential copper separation are then subjected to a sulfur flotation process of one roughing, two scavenging and two cleaning processes.

[0027] (3) Based on the high mud content of the raw ore, this invention adopts pre-screening and grading grinding without desliming, which reduces the over-grinding phenomenon during ore grinding and reduces the impact of mud on the copper-sulfur flotation environment, thus obtaining high-quality copper concentrate and qualified sulfur concentrate products, and realizing the purpose of comprehensive utilization of mineral resources in a low-alkali environment. Attached Figure Description

[0028] Figure 1 This is a process flow diagram of the flotation method for high-sulfur, muddy copper ore according to the present invention.

[0029] Figure 2 This is the process flow diagram for Comparative Example 11.

[0030] Figure 3 This is the process flow diagram for Comparative Example 12. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0033] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0034] like Figure 1 As shown, the present invention provides a flotation method for high-sulfur copper ore containing mud, comprising the following steps:

[0035] S1. Preparation of slurry:

[0036] The raw ore to be processed is pre-screened and classified using a 0.045mm standard sieve. The ore particles larger than 0.045mm are ball-milled to a predetermined fineness and mixed with the undersize ore to prepare a slurry with a mass concentration of 30%–45%. The slurry contains 50%–90% ore particles smaller than 0.074mm. The mud content in the raw ore to be processed is 5%–20%.

[0037] On the one hand, pre-screening and grading are carried out, and only the larger particles of ore are ground, reducing mud formation during grinding. On the other hand, grinding the raw ore to a certain fineness allows the various mineral components in the raw ore to be mechanically dissociated, which is more conducive to subsequent ore beneficiation processes.

[0038] S2. Select copper:

[0039] The slurry obtained in step S1 is subjected to two roughing processes, three scavenging processes, and two cleaning processes to obtain copper concentrate and copper tailings.

[0040] Specifically, 500–7000 g / t of pyrite composite inhibitor is added to the slurry to adjust the pH to 7–9. 10–150 g / t of copper collector and 10–50 g / t of frother are added for the first copper roughing process, yielding roughed copper concentrate I and roughed copper middlings I. Then, 0–1000 g / t of pyrite composite inhibitor and 5–100 g / t of copper collector are added to roughed copper middlings I for the second copper roughing process, yielding roughed copper concentrate II and roughed copper middlings II. The pyrite composite inhibitor is composed of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid, wherein the mass ratio of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid is (2–4):(1–3):(1–3):(1–3):(0.5–2). The copper collector is one or more of ethyl thiocyanate, ester 105, ethyl xanthate, isopropyl xanthate, and butyl ammonium black powder; the foaming agent is one of methyl isobutyl methanol and hexanol methyl pentanol.

[0041] After mixing rougher copper concentrate I and rougher copper concentrate II, 50–2000 g / t of pyrite composite depressant is added for the first copper cleaning process, yielding cleaned copper concentrate I and cleaned copper middlings I. 0–1000 g / t of pyrite composite depressant is added to cleaned copper concentrate I for the second copper cleaning process, yielding copper concentrate and cleaned copper tailings II. Cleaned copper tailings II are returned to the first copper cleaning operation.

[0042] Add 0-2000 g / t of pyrite composite depressant and 0-60 g / t of copper collector to the rougher copper middlings II for the first copper scavenging, yielding scavenged copper concentrate I and scavenged copper middlings I. Add 0-1500 g / t of pyrite composite depressant and 0-40 g / t of copper collector to the scavenged copper middlings I for the second copper scavenging, yielding scavenged copper concentrate II and scavenged copper middlings II. Add 0-1000 g / t of pyrite composite depressant and 0-20 g / t of copper collector to the scavenged copper middlings II for the third copper scavenging, yielding scavenged copper concentrate III and copper tailings. Scavenged copper concentrate III is returned to the first scavenging operation.

[0043] Next, scavenged copper concentrate I (i.e., the concentrate from the first copper scavenging), scavenged copper concentrate II (i.e., the concentrate from the second copper scavenging), and refined copper middlings I (i.e., the middlings from the first copper refining) are mixed, and pyrite composite inhibitors of 0-2000 g / t are added. After regrinding, a regrinding slurry with a mass concentration of 5%-20% (slurry pH value of 7-9) is obtained; the ore with a particle size of less than 0.038 mm accounts for 50%-90% of the regrinding slurry. This setup, by mixing and regrinding scavenged copper concentrate I, scavenged copper concentrate II, and refined copper middlings I, instead of directly returning them to the previous stage of the process, reduces the circulation time of argillaceous gangue minerals and pyrite in the closed-loop cycle, thereby improving the separation efficiency of copper from pyrite, argillaceous gangue, and other minerals. Simultaneously, by regrinding the mixed middlings to a suitable fineness, copper achieves a high degree of liberation from pyrite and gangue minerals, and a suitable regrinding slurry concentration is prepared. Combined with the use of pyrite composite depressant, this enhances the efficient separation of copper and pyrite. Furthermore, by first adding the pyrite composite depressant to the mixture of scavenged copper concentrate I, scavenged copper concentrate II, and refined copper middlings I, and then regrinding, the mixed middlings and pyrite composite depressant are fully contacted during the grinding process, further improving the separation effect of copper and pyrite.

[0044] Add 5-50 g / t of copper collector to the regrinding slurry for the first copper concentrator scavenging, yielding scavenged copper concentrate I and scavenged copper middlings I. Scavenged copper concentrate I is returned to the first copper cleaning operation (i.e., rougher copper concentrate I, rougher copper concentrate II, cleaned copper tailings II, and scavenged copper concentrate I returned to the first copper cleaning operation). Add 0-1000 g / t of pyrite composite depressant and 0-40 g / t of copper collector to scavenged copper middlings I for the second copper concentrator scavenging, yielding scavenged copper concentrate II and scavenged copper tailings II (i.e., copper concentrator tailings). Scavenged copper concentrate II is returned to the first copper concentrator scavenging operation.

[0045] In copper beneficiation processes, the addition of a pyrite composite inhibitor effectively suppresses pyrite, separating it from copper sulfide. A frother causes the copper ore to adhere to the surface of air bubbles and float, ultimately separating the copper ore under the action of a collector. Specifically, the pyrite composite inhibitor is composed of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid.

[0046] First, with the synergistic effect of lime and sodium hydroxide, the slurry is adjusted to a suitable alkalinity. Hydroxide ions generated from the hydrolysis of lime and sodium hydroxide adhere to the surface of pyrite, forming a hydrophilic film that adsorbs pyrite into the slurry, achieving the separation of copper sulfide and pyrite. Simultaneously, the presence of calcium ions forms insoluble calcium sulfide on the pyrite surface, reducing the amount of collector adsorbed by pyrite and further inhibiting pyrite formation. Sodium thiosulfate, as a strong reducing agent, reduces ferric and ferrous ions in the slurry or generates complex ions. Sodium dimethyl dithiocarbamate, as a salt of small organic molecules, and citric acid containing hydrophilic carboxyl groups, bond with each other. These substances work synergistically to form a dense hydrophilic film on the surface of pyrite, maximizing the inhibition of pyrite formation.

[0047] S3. Sulfur selection:

[0048] Add 0-100 g / t of activator, 50-200 g / t of pyrite collector, and 0-40 g / t of frother to the copper tailings obtained from the third copper scavenging in step S2 for a primary sulfur roughing process to obtain roughed sulfur concentrate and roughed sulfur middlings. The activator is copper sulfate; the pyrite collector is one or more of isoamyl xanthate, butyl xanthate, and isopropyl xanthate; and the frother is pine oil.

[0049] During this process, under the action of the activator, sulfur minerals can better combine with the collector, thereby achieving a highly efficient mineral processing effect.

[0050] The rough sulfur concentrate and the copper concentrate tailings obtained in step S2 (i.e., fine copper tailings II) are combined and subjected to a first sulfur refining process to obtain refined sulfur concentrate I and refined sulfur middlings I. Refined sulfur middlings I is returned to the sulfur roughing operation. Refined sulfur concentrate I is subjected to a second sulfur refining process to obtain sulfur concentrate and refined sulfur tailings II. Refined sulfur tailings II is returned to the first sulfur refining operation.

[0051] A first sulfur scavenging process involves adding 10–100 g / t of pyrite collector to the roughing middlings ore to obtain scavenged sulfur concentrate I and scavenged middlings ore I. Scavenged sulfur concentrate I is then returned to the sulfur roughing process (i.e., both the cleaned middlings ore I and the scavenged sulfur concentrate I are returned to the sulfur roughing process). A second sulfur scavenging process involves adding 0–50 g / t of pyrite collector to scavenged middlings ore I to obtain scavenged sulfur concentrate II and tailings. Scavenged sulfur concentrate II is then returned to the first sulfur scavenging process.

[0052] The present invention will now be described in detail through specific embodiments.

[0053] Example 1

[0054] This embodiment uses a clayey, high-sulfur copper ore as the object. The raw ore sample contains approximately 10% clay (less than 20 μm), 0.68% copper, and 25.40% sulfur. The main gangue minerals are quartz, muscovite, chlorite, feldspar, and quartz-sericite. The flotation of this clayey, high-sulfur copper ore includes the following steps:

[0055] S1. Preparation of slurry:

[0056] The raw ore to be selected is pre-screened and classified using a standard sieve with a particle size of 0.045mm. The ore with a particle size greater than 0.045mm is ball-milled to a predetermined fineness. The ore with a particle size less than 0.074mm accounts for 70% of the slurry. It is then mixed with the ore under the sieve to prepare a slurry with a mass concentration of 40%.

[0057] S2. Select copper:

[0058] The slurry obtained in step S1 is subjected to two roughing processes, three scavenging processes, and two cleaning processes to obtain copper concentrate and copper tailings.

[0059] Specifically, 5000 g / t of pyrite composite depressant was added to the slurry and stirred for 3 min. The pH was adjusted to 7.5. 30 g / t of copper collector was added and stirred for 3 min. 10 g / t of methyl isobutyl methanol was added and stirred for 1 min. Aeration flotation was performed for 3 min to conduct the first copper roughing, yielding roughed copper concentrate I and roughed copper middlings I. Then, 800 g / t of pyrite composite depressant was added to roughed copper middlings I and stirred for 3 min. 20 g / t of copper collector was added and aeration flotation was performed for 2.5 min to conduct the second copper roughing, yielding roughed copper concentrate II and roughed copper middlings II. The pyrite composite depressant was composed of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid, with a mass ratio of 3:2:2:2:1. The copper collector is a compound of ethyl thiocyanate, ethyl xanthate, and butyl ammonium black powder in a mass ratio of 6:3:1.

[0060] After mixing rougher copper concentrate I and rougher copper concentrate II, 1000 g / t of pyrite composite depressant is added and stirred for 3 min, followed by aeration flotation for 2 min for the first copper cleaning process, yielding cleaned copper concentrate I and cleaned copper middlings I. Then, 500 g / t of pyrite composite depressant is added to cleaned copper concentrate I, stirred for 3 min, followed by aeration flotation for 1.5 min for the second copper cleaning process, yielding copper concentrate and cleaned copper tailings II. Cleaned copper tailings II are returned to the first copper cleaning operation.

[0061] Add 600 g / t of pyrite composite depressant to rougher copper middlings II, stir thoroughly for 3 minutes, add 12 g / t of copper collector, and perform aeration flotation for 2 minutes for the first copper scavenging process, yielding scavenged copper concentrate I and scavenged copper middlings I. Add 300 g / t of pyrite composite depressant to scavenged copper middlings I, stir thoroughly for 3 minutes, add 8 g / t of copper collector, and perform aeration flotation for 2 minutes for the second copper scavenging process, yielding scavenged copper concentrate II and scavenged copper middlings II. Add 4 g / t of copper collector to scavenged copper middlings II, and perform aeration flotation for 2 minutes for the third copper scavenging process, yielding scavenged copper concentrate III and copper tailings. Scavenged copper concentrate III is returned to the first scavenging operation.

[0062] Next, scavenged copper concentrate I (i.e., the concentrate from the first copper scavenging), scavenged copper concentrate II (i.e., the concentrate from the second copper scavenging), and refined copper middlings I (i.e., the middlings from the first copper refining) are mixed. 1000 g / t of pyrite composite depressant is added before regrinding. 80% of the regrinded ore has a particle size smaller than 0.038 mm, resulting in a regrinding slurry with a mass concentration of 14% (slurry pH value of 9). 12 g / t of copper collector is added to the regrinding slurry and stirred for 3 min. Aeration flotation is then performed for 2.5 min to conduct the first copper refining, yielding refined scavenged copper concentrate I and refined scavenged copper middlings I. Refined scavenged copper concentrate I is returned to the first copper refining operation (i.e., rougher copper concentrate I, rougher copper concentrate II, refined copper tailings II, and refined scavenged copper concentrate I are all returned to the first copper refining operation). Add 500 g / t of pyrite composite inhibitor to copper middlings I and stir for 3 min. Add 6 g / t of copper collector and stir for 3 min. Then, perform aeration flotation for 2 min and carry out a second copper scavenging to obtain copper concentrate II and copper tailings II (i.e. copper scavenging tailings). Copper concentrate II is returned to the first copper scavenging operation.

[0063] S3. Sulfur selection:

[0064] Add 50 g / t of copper sulfate activator to the copper tailings obtained from the third copper scavenging in step S2 and stir for 3 min, add 120 g / t of butyl xanthate collector for pyrite and stir for 3 min, add 5 g / t of pine oil frother and stir for 1 min, then perform aeration flotation for 3 min to carry out one sulfur roughing to obtain rough sulfur concentrate and rough sulfur middlings.

[0065] The rough sulfur concentrate and the copper concentrate tailings obtained in step S2 (i.e., fine copper tailings II) are combined and subjected to a first sulfur cleaning process. No reagents are added during this first sulfur cleaning process. After stirring for 1 minute, aeration flotation is performed for 2 minutes, yielding cleaned sulfur concentrate I and cleaned middlings I. Cleaned middlings I is returned to the rough sulfur separation operation. Cleaned sulfur concentrate I undergoes a second sulfur cleaning process. No reagents are added during this second sulfur cleaning process. After stirring for 1 minute, aeration flotation is performed for 1 minute, yielding sulfur concentrate and cleaned sulfur tailings II. Cleaned sulfur tailings II is returned to the first sulfur cleaning operation.

[0066] Add 30 g / t of butyl xanthate to the rougher middlings for the first sulfur scavenging process. After stirring for 3 minutes, aeration and flotation are performed for 2 minutes to obtain scavenged sulfur concentrate I and scavenged middlings I. Scavenged sulfur concentrate I is returned to the sulfur roughing process (i.e., both the cleaned middlings I and the scavenged sulfur concentrate I are returned to the sulfur roughing process). Add 15 g / t of butyl xanthate to scavenged middlings I, stir for 3 minutes, and aeration and flotation are performed for 2 minutes for the second sulfur scavenging process to obtain scavenged sulfur concentrate II and tailings. Scavenged sulfur concentrate II is returned to the first sulfur scavenging process.

[0067] Example 2-3

[0068] A flotation method for high-sulfur copper ore containing mud differs from Example 1 in that the mass ratio of each substance in the pyrite composite inhibitor is different in step S2. Otherwise, it is largely the same as Example 1 and will not be repeated here.

[0069] In Example 2, the mass ratio of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in the pyrite composite inhibitor is 2:3:2:2:1.

[0070] In Example 3, the mass ratio of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in the pyrite composite inhibitor was 4:2:1:1:2.

[0071] The yield and grade of copper concentrate, sulfur concentrate and tailings obtained in Examples 1-3 were compared, and the results are shown in Table 1.

[0072] Table 1 Comparison of copper concentrate, sulfur concentrate, and tailings in Examples 1-3

[0073]

[0074] As shown in Table 1, the copper-sulfur separation process in Examples 1-3, combined with the pyrite composite inhibitor, resulted in copper concentrate products that met or exceeded Grade III standards according to the People's Republic of China Nonferrous Metals Industry Copper Concentrate Standard (YS / T318-2007), with a copper recovery rate exceeding 89%, achieving highly efficient separation of chalcopyrite and pyrite. In Examples 2 and 3, minor adjustments were made to the proportions of the various reagents in the pyrite composite inhibitor, but the grade and recovery rate of the resulting copper concentrate remained largely unchanged, indicating that the pyrite composite inhibitors provided in Examples 1-3 all achieved good results.

[0075] Comparative Examples 1-5

[0076] A flotation method for high-sulfur copper ore containing mud differs from Example 1 in that the mass ratio of each substance in the pyrite composite inhibitor is different in step S2. Otherwise, it is largely the same as Example 1 and will not be repeated here.

[0077] The mass ratios of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in the pyrite composite inhibitors in Comparative Examples 1-5 are shown in Table 2.

[0078] Table 2. Mass ratio of each substance in the pyrite composite inhibitor.

[0079] Example mass ratio Comparative Example 1 0:2:2:2:1 Comparative Example 2 3:0:2:2:1 Comparative Example 3 3:2:0:2:1 Comparative Example 4 3:2:2:0:1 Comparative Example 5 3:2:2:2:0

[0080] The yields and grades of copper concentrate, sulfur concentrate, and tailings obtained from Comparative Examples 1-5 were compared, and the results are shown in Table 3.

[0081] Table 3 Comparison of copper concentrate, sulfur concentrate, and tailings in Examples 1-5 of the embodiments

[0082]

[0083]

[0084] As shown in Table 3, when no one of the pyrite composite inhibitors is added, the copper grade and copper recovery rate in the copper concentrate both decrease. Meanwhile, the copper grade and recovery rate in the sulfur concentrate of Comparative Examples 1-5 are relatively high, indicating that the separation effect of copper and sulfur is not good. This results in a high copper content in the sulfur concentrate, indicating a high copper metal loss rate. It is evident that the inhibitory effect of the pyrite composite inhibitor in Comparative Examples 1-5 is not good, thus leading to a poor separation effect of copper and sulfur.

[0085] Comparative Example 6

[0086] A flotation method for high-sulfur copper ore containing mud, which differs from Example 1 in that, in step S2, the lime in the pyrite composite inhibitor is replaced with calcium chloride. The rest is roughly the same as in Example 1 and will not be described in detail here.

[0087] Comparative Example 7

[0088] A flotation method for high-sulfur copper ore containing mud, which differs from Example 1 in that, in step S2, sodium thiosulfate in the pyrite composite inhibitor is replaced with sodium sulfite. The rest is roughly the same as in Example 1 and will not be repeated here.

[0089] Comparative Example 8

[0090] A flotation method for high-sulfur copper ore containing mud, which differs from Example 1 in that, in step S2, sodium dimethyl dithiocarbamate in the pyrite composite inhibitor is replaced with sodium humate. The rest is largely the same as in Example 1 and will not be repeated here.

[0091] Comparative Example 9

[0092] A flotation method for high-sulfur copper ore containing mud differs from Example 1 in that, in step S2, the pyrite composite inhibitor is a mixture of sodium dimethyl dithiocarbamate: sodium thiosulfate: citric acid = 4:4:2 (mass ratio). The other steps are largely the same as in Example 1 and will not be repeated here.

[0093] Comparative Example 10

[0094] A flotation method for high-sulfur copper ore containing mud, compared with Example 1, differs in that, in step S2, the pyrite composite inhibitor is sodium thiosulfate: sodium sulfite = 5.5:4.5 (mass ratio). Other reagent formulations are largely the same as those in Example 4 of patent application number CN201810548647.6, except that the pH value is adjusted to be greater than 12. Other aspects are largely the same as in Example 1 and will not be repeated here.

[0095] The yields and grades of copper concentrate, sulfur concentrate, and tailings obtained from Comparative Examples 6-10 were compared, and the results are shown in Table 4.

[0096] Table 4 compares the copper concentrate, sulfur concentrate, and tailings in Examples 6-10 of the embodiments.

[0097]

[0098]

[0099] As shown in Table 4, in Comparative Examples 6-8, replacing each agent in the pyrite composite inhibitor with the same type of pyrite inhibitor resulted in poor separation of copper and pyrite. In Comparative Example 9, without using traditional pyrite inhibitors such as lime and sodium hydroxide, the separation of copper and pyrite was relatively poor.

[0100] As can be seen from the data of Comparative Example 10, the copper recovery rate of copper concentrate and the sulfur recovery rate of sulfur concentrate were significantly reduced when using the pyrite composite inhibitor with patent application number CN201810548647.6. This is because the excessively high pH value inhibited the floatability of copper, resulting in a large loss of copper metal. Furthermore, it was found that adding only copper sulfate activator in the downstream sulfur beneficiation process was insufficient to improve the sulfur recovery rate. A large amount of acid was required to adjust the pH, which increased the cost of reagents and labor. This contradicts the low alkalinity process of the invention patent.

[0101] Comparative Example 11

[0102] A flotation method for high-sulfur, muddy copper ore, differing from Example 1 in that pre-screening is not performed in step S1. The specific process flow is as follows. Figure 2 As shown, the rest is largely the same as in Example 1, and will not be repeated here.

[0103] Comparative Example 12

[0104] A flotation method for high-sulfur, muddy copper ore, differing from Example 1, in that, in step S2, the scavenged copper concentrate I, scavenged copper concentrate II, and refined copper middlings I are not mixed and regrinded; instead, the mixture is directly returned to the previous process flow. The specific process flow is as follows. Figure 3 As shown, the rest is largely the same as in Example 1, and will not be repeated here.

[0105] The yields and grades of copper concentrate, sulfur concentrate, and tailings obtained from Comparative Examples 11-12 were compared, and the results are shown in Table 5.

[0106] Table 5 compares the copper concentrate, sulfur concentrate, and tailings in Comparative Examples 11-12 of the Examples.

[0107]

[0108] As shown in Table 5, if the conventional copper-sulfur separation process is used, the copper grade and copper recovery rate in the obtained copper concentrate will be low, resulting in increased subsequent metallurgical costs and waste of mineral resources.

[0109] In summary, the flotation method for high-sulfur, muddy copper ore provided by this invention first pre-screens and classifies the minerals to be processed. Then, a copper-preferential separation process is performed. A pyrite composite depressant is obtained by compounding lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in a specific ratio. The synergistic effect of the substances in the pyrite composite depressant maximizes the suppression of pyrite, achieving efficient separation of copper and pyrite. Simultaneously, middlings are mixed and regrinded to further enhance the efficient separation of copper and pyrite. Finally, under the action of an activator, a pyrite collector, and a frother, efficient separation of sulfur is achieved, ultimately yielding two qualified products: copper concentrate and sulfur concentrate.

[0110] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for the flotation of clay-containing high-sulfur copper ores, characterized in that, Includes the following steps: S1. The raw ore to be selected is pre-screened and classified, and the ore on the screen is ball-milled to a predetermined fineness and mixed with the ore under the screen to prepare a slurry of a predetermined concentration; S2. The slurry obtained in step S1 is subjected to two copper roughing processes to obtain rough copper concentrate and rough copper middlings; the obtained rough copper concentrate is then subjected to two copper cleaning processes to obtain copper concentrate, and the rough copper middlings are subjected to three copper scavenging processes to obtain copper tailings; the middlings from the first copper cleaning of the rough copper concentrate, the concentrate from the first copper scavenging of the rough copper middlings, and the concentrate from the second copper scavenging of the rough copper middlings are mixed and regrinded, and then subjected to two copper refining and scavenging processes to obtain copper refining and scavenging concentrate and copper refining and scavenging tailings; pyrite composite inhibitors are added during the copper roughing, copper cleaning, copper scavenging, and copper refining and scavenging processes, and the pyrite composite inhibitors are composed of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid. S3. Perform a first sulfur roughing process on the copper tailings obtained in step S2 to obtain rough sulfur concentrate and rough sulfur middlings; combine the rough sulfur concentrate and the copper concentrate scavenging tailings obtained in step S2 and perform two sulfur cleaning processes to obtain sulfur concentrate; perform two sulfur scavenging processes on the rough sulfur middlings to obtain tailings.

2. The slime-containing high-sulfur type copper ore flotation method according to claim 1, characterized by, In step S2, the mass ratio of lime, sodium thiosulfate, sodium dimethyl dithiocarbamate, sodium hydroxide, and citric acid in the pyrite composite inhibitor is (2-4):(1-3):(1-3):(1-3):(0.5-2).

3. The slime-containing high-sulfur type copper ore flotation method according to claim 1, characterized by, In step S1, the pre-screening and grading uses a 0.045mm standard sieve to grind the ore with a particle size greater than 0.045mm; after grinding, it is mixed with the undersize ore to prepare a slurry with a mass concentration of 40%, in which 70% of the slurry is ore with a particle size less than 0.074mm.

4. The slime-containing high-sulfur type copper ore flotation method according to claim 1, characterized by, In step S2, during the two copper roughing processes, the dosage of pyrite composite inhibitor in the first copper roughing process is 5000 g / t, the dosage of copper collector is 30 g / t, and the dosage of frother is 10 g / t; in the second copper roughing process, the dosage of pyrite composite inhibitor is 800 g / t, and the dosage of copper collector is 20 g / t. In the two copper beneficiation processes, the dosage of pyrite compound inhibitor was 1000 g / t in the first copper beneficiation process and 500 g / t in the second copper beneficiation process. In the three copper scavenging processes, the dosage of pyrite compound inhibitor was 600 g / t and the dosage of copper collector was 12 g / t in the first copper scavenging process; the dosage of pyrite compound inhibitor was 300 g / t and the dosage of copper collector was 8 g / t in the second copper scavenging process; and the dosage of pyrite compound inhibitor was 0 g / t and the dosage of copper collector was 4 g / t in the third copper scavenging process.

5. The flotation method for muddy, high-sulfur copper ore according to claim 4, characterized in that, In step S2, the copper collector is one or more of ethyl thiocyanate, ester 105, ethyl xanthate, isopropyl xanthate, and butyl ammonium black powder; the foaming agent is methyl isobutyl methanol.

6. The flotation method for muddy, high-sulfur copper ore according to claim 1, characterized in that, In step S2, the middlings from the first copper beneficiation, the concentrate from the first copper scavenging, and the concentrate from the second copper scavenging are mixed and regrinded to obtain a regrinding slurry with a mass concentration of 14%; 80% of the regrinding slurry contains ore with a particle size of less than 0.038 mm.

7. The flotation method for muddy, high-sulfur copper ore according to claim 5, characterized in that, In the two copper concentrate scavenging processes, the dosage of pyrite composite inhibitor in the first copper concentrate scavenging process was 1000 g / t, and the dosage of copper collector was 12 g / t; in the second copper concentrate scavenging process, the dosage of pyrite composite inhibitor was 500 g / t, and the dosage of copper collector was 6 g / t.

8. The flotation method for muddy, high-sulfur copper ore according to claim 1, characterized in that, In step S3, during the rough selection of sulfur, an activator, a pyrite collector, and a frother are added.

9. The flotation method for muddy, high-sulfur copper ore according to claim 8, characterized in that, The activator is copper sulfate; the pyrite collector is one or more of isoamyl xanthate, butyl xanthate, and isopropyl xanthate; and the foaming agent is pine oil.

10. The flotation method for muddy, high-sulfur copper ore according to claim 1, characterized in that, In step S2, the concentrate from the first copper roughing, the concentrate from the second copper roughing, the concentrate from the first copper scavenging, and the tailings from the second copper cleaning are mixed and then enter the first copper cleaning operation; the tailings from the second copper scavenging, the concentrate from the first sulfur roughing, and the tailings from the second sulfur cleaning are mixed and then enter the first sulfur cleaning operation.

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