A method for processing copper-sulfur-iron gold-silver ore

Abstract

This invention belongs to the field of mineral processing technology, specifically relating to a method for processing copper-sulfur-iron gold-silver ore, including grinding-flotation copper pre-enrichment; middlings fine grinding-secondary copper enrichment and sulfur pre-enrichment; secondary sulfur enrichment; weak magnetic recovery of magnetite; strong magnetic roughing of siderite; fine grinding-concentrate flotation-recovery of siderite concentrate. This invention fully recovers copper, sulfur, and the associated gold and silver minerals, while also recovering the gold and silver minerals associated with magnetite and siderite. By recovering the initially liberated copper and sulfur minerals at the front end of the beneficiation process, and by finely grinding the intergrowth minerals in the scavenging concentrate and middlings, it avoids the muddying of the slurry caused by over-grinding of the raw ore, which increases the difficulty of recovery; simultaneously, it enriches gold and silver in the copper concentrate, laying the foundation for subsequent secondary sulfur enrichment and efficient recovery of magnetite and siderite. This invention achieves efficient gradient-level recovery of gold, silver, copper, magnetite, siderite, and sulfur, maximizing resource utilization while optimizing the concentrated enrichment of gold and silver in the copper concentrate.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, specifically relating to a method for processing copper-sulfur-iron gold-silver ore. Background Technology

[0002] Copper-pyrite-iron gold-silver ore is a typical complex polymetallic symbiotic ore with a complex mineral composition. Copper, sulfur, and iron minerals are closely associated. Copper and sulfur minerals mainly exist in the form of chalcopyrite and pyrite sulfides. Gold, silver, and other precious metals often occur as fine-grained and micro-fine-grained native gold, native silver, and silver-manganese ore, associated with sulfide minerals, iron minerals (magnetite, siderite), and gangue. The gangue is mainly composed of quartz and carbonates. The gangue minerals in copper-pyrite-iron gold-silver ore are mainly quartz, carbonates, and a small amount of aluminosilicates, with a gangue content of 40%-50%; Cu content 0.2%-0.35%; Au content 1.5g / t-2.5g / t; Ag content 20g / t-35g / t; S content 6%-8%; TFe content 23%-33%; mFe content 3%-5%; SiD content 20%-30%.

[0003] Currently, the traditional beneficiation process for these minerals, known as "preferential copper flotation followed by sequential sulfur flotation," is commonly used. This process includes four main steps: single-stage grinding, copper flotation, sequential sulfur flotation, and magnetic separation. This process has the following drawbacks: 1. Single-stage grinding of the ore results in insufficient liberation of valuable minerals during coarse grinding, leading to low recovery rates of copper, gold, and silver. Over-grinding, on the other hand, easily causes mud formation in the pulp, deteriorating the flotation environment and causing severe mud adhesion to the concentrate. Furthermore, during the magnetic separation stage, incomplete liberation during coarse grinding or mud formation during over-grinding both cause the loss of magnetite and siderite, further resulting in the loss of gold and silver. 2. During copper flotation, the use of high alkali to suppress pyrite simultaneously inhibits the formation of "copper-sulfur," "gold-sulfur," and "gold-iron" intergrowths, leading to low yields of gold and silver in high-value copper concentrates. Summary of the Invention

[0004] To address the above problems, this invention provides a method for processing copper-sulfur-iron gold-silver ore, comprising the following steps: (1) Grinding-flotation copper pre-enrichment: The copper-sulfur iron gold-silver ore is ground and classified, and sodium sulfide and lime are added to obtain a grinding and washing slurry with 80%-83% of -200 mesh and pH 8.5-9.0; the grinding and washing slurry is fed into the flotation machine, and Z200 is added to carry out copper roughing operation to obtain copper roughing concentrate and copper roughing tailings; the copper roughing concentrate is fed into the flotation machine to carry out copper cleaning operation, and reagents including lime, sodium sulfite and water glass are added to obtain copper cleaning middlings and pre-enriched copper concentrate.

[0005] This step grinds the ore to -200 mesh (80%-83%), initially liberating the gangue from copper, sulfur, and iron minerals and preventing valuable minerals from being trapped within the gangue. Sodium sulfide and lime are added as depressants, creating an alkaline environment (pH 8.5-9.0) to precipitate interfering oxide metal ions in the ore and initially suppress sulfur. This is then combined with Z200 for copper roughing, ensuring copper is separated first and prioritizing the enrichment of copper, gold, and silver in the copper roughing concentrate. The copper roughing concentrate is further refined through cleaning to further enrich the fully liberated copper (chalcopyrite), gold, and silver, yielding a pre-enriched copper concentrate. Z200 acts as a collector for gold, silver, and copper; lime and sodium sulfite act as a combined sulfur depressant; and water glass acts as a gangue depressant.

[0006] Thus, the roughing process enriches most of the high-value copper-containing, gold- and silver-containing minerals, while the fine processing prioritizes the separation of the completely liberated copper minerals. The combination of these two processes provides the conditions for subsequent middlings and fine grinding.

[0007] (2) Fine grinding of middlings - secondary enrichment of copper and pre-enrichment of sulfur: The copper roughing tailings from step (1) are fed into the flotation machine with Z200 for copper scavenging to obtain copper scavenging rough concentrate and copper scavenging tailings; the copper scavenging rough concentrate and the copper middlings from step (1) are finely ground and classified to obtain overflow slurry with -400 mesh accounting for 90%-93%; the overflow slurry is fed into the flotation machine for copper-sulfur separation roughing to float copper, gold and silver to obtain copper-containing flotation concentrate and sulfur-containing flotation tailings; the copper-containing flotation concentrate is further refined to obtain secondary enriched copper concentrate after copper, gold and silver are refined; the tailings can be returned to the previous refinement or copper-sulfur separation roughing operation, or directly discharged; the sulfur-containing flotation tailings are scavenged to obtain pre-enriched sulfur concentrate after pyrite; the tailings can be returned to the previous scavenging or copper-sulfur separation roughing operation, or directly discharged. If the tailings from the selection and scavenging processes are returned to the previous process for re-selection and recycling, they can be discharged as useless tailings.

[0008] This copper scavenging step involves adding Z200 as a collector for intergrowths of gold and copper, further enriching and recovering the "copper-sulfur," "gold-sulfur," and "gold-gangue" intergrowths in the copper roughing tailings into the copper scavenging concentrate. The copper scavenging concentrate, along with the copper middlings containing similar "copper-sulfur," "gold-sulfur," and "gold-gangue" intergrowths, is then finely ground to -400 mesh (90%-93%) to fully liberate the intergrowths, thus preparing them for further separation and beneficiation. The overflow slurry obtained after fine grinding undergoes roughing, beneficiation, and scavenging processes, enriching the fully liberated gold and silver in the copper concentrate to obtain a secondary enriched copper concentrate containing gold and silver. The flotation tailings yield a pre-enriched sulfur concentrate. This achieves the goals of pre-enrichment of gold, copper, and silver, targeted grinding, and efficient separation and beneficiation. Simultaneously, the pre-enrichment of sulfur significantly reduces the amount of subsequent secondary sulfur enrichment slurry and optimizes reagent utilization.

[0009] (3) Secondary enrichment of sulfur: The copper scavenging tailings from step (2) are fed into a flotation machine for sulfur roughing operation, pyrite is floated to obtain sulfur roughing concentrate and sulfur roughing tailings. The sulfur roughing concentrate is further refined into pyrite to obtain secondary enriched sulfur concentrate. The refined tailings are finally re-entered into sulfur roughing operation. The sulfur roughing tailings are scavenged into pyrite to obtain sulfur scavenging concentrate and sulfur scavenging tailings. The sulfur scavenging concentrate is returned to sulfur roughing operation.

[0010] This step utilizes flotation for roughing, scavenging, and cleaning processes to recover the liberated sulfur (pyrite) and obtain a secondary enriched sulfur concentrate. At this point, copper and sulfur recovery are complete, and the remaining valuable minerals in the sulfur scavenging tailings are mainly iron minerals and some gold and silver associated with these minerals.

[0011] (4) Weak magnetic recovery of magnetite: The sulfur scavenging tailings from step (3) are fed into a magnetic separator for weak magnetic separation of magnetite to obtain magnetite concentrate and weak magnetic separation tailings. This step enriches the magnetite in the sulfur scavenging tailings, fully recovering the remaining magnetite.

[0012] (5) Strong magnetic roughing of siderite: The weak magnetic separation tailings from step (4) are subjected to strong magnetic roughing of siderite to obtain siderite concentrate and strong magnetic roughing tailings. This step utilizes a high-intensity magnetic separator to enrich siderite in the tailings from the low-intensity magnetic separation, fully recovering the siderite rough concentrate and allowing for the recovery of the remaining gold and silver carrier minerals, thus providing conditions for further gold and silver extraction. The tailings from the high-intensity magnetic roughing separation are discarded as useless tailings.

[0013] (6) Fine grinding-flotation of gold and silver-recovery of siderite concentrate: The siderite rough concentrate from step (5) is finely ground and classified to obtain an overflow slurry with a -400 mesh content of 92%-95%; the overflow slurry is fed into a flotation machine for gold and silver flotation, and gold and silver are floated. The flotation concentrate is gold concentrate, and the flotation tailings are fed into a magnetic separator for strong magnetic separation of siderite to obtain siderite concentrate and strong magnetic separation tailings. The strong magnetic separation tailings are the final tailings and can be discharged.

[0014] This step involves fine grinding of the enriched siderite concentrate to further liberate the gold and silver content from the siderite, creating favorable conditions for subsequent gold and silver separation. The gold and silver are then floated using a flotation machine to obtain a qualified gold concentrate. Finally, a high-intensity magnetic separator is used to thoroughly clean the flotation tailings to obtain the siderite concentrate, achieving the final recovery of all valuable elements from the original ore.

[0015] Further, after grinding and classifying the ore in step (1), 500g / t-800g / t of sodium sulfide and 2000g / t-2500g / t of lime are added to obtain a grinding and washing slurry; in the copper roughing operation, the amount of Z200 added is 20g / t-30g / t; the flotation reagents added in the copper beneficiation operation include 500g / t-1000g / t of lime, 200g / t-300g / t of sodium sulfite and 150g / t-250g / t of water glass.

[0016] Furthermore, in step (1), the copper roughing operation is a two-stage roughing operation, and the copper cleaning operation is a three-stage cleaning operation.

[0017] The reagent addition amounts for the copper roughing and copper cleaning processes mentioned above refer to the addition amounts for each roughing and cleaning stage.

[0018] Furthermore, the concentration of the grinding slurry in step (1) is 32%-35%, the concentration of the overflow slurry in step (2) is 25%-28%, and the concentration of the overflow slurry in step (6) is 30%-32%.

[0019] Furthermore, in step (2), the amount of Z200 added in the copper scavenging operation is 10g / t-15g / t; the flotation reagents added in the copper-sulfur separation roughing operation include 500g / t-800g / t of lime, 250g / t-300g / t of sodium humate and 5g / t-10g / t of Z200; the flotation reagents added when the copper concentrate is flotated include 300g / t-600g / t of lime and 220g / t-260g / t of sodium humate; and the flotation reagents added when the sulfur tailings are flotated include 5g / t-10g / t of Z200.

[0020] The added lime and sodium humate act as a combined inhibitor of sulfur and gangue, while Z200 acts as a collector for gold, silver, and copper.

[0021] Furthermore, in step (3), the sulfur roughing tailings scavenging is carried out in two stages. The reagents added in the first stage of scavenging include 120g / t-150g / t of butyl xanthate, and the reagents added in the second stage of scavenging include 100g / t-130g / t of pentyl xanthate.

[0022] By using a collector with milder collecting properties to preemptively collect sulfur with good floatability, and then using a collector with stronger collecting properties (pentyl xanthate) for secondary collection, high-quality sulfur recovery and high recovery rate were finally achieved.

[0023] Furthermore, in step (3), the flotation reagents added to the sulfur roughing operation include 220g / t-260g / t of butyl xanthate and 250g / t-350g / t of copper sulfate, and the flotation reagents added when the sulfur roughing concentrate is cleaned include 120g / t-150g / t of water glass.

[0024] The added butyl xanthate and pentyl xanthate are sulfur collectors, copper sulfate is an activator, and water glass is a gangue inhibitor, which ensures the quality of the concentrate while achieving efficient and full recovery of sulfur.

[0025] Furthermore, in step (4), the weak magnetic separation is a two-stage weak magnetic separation. The sulfur scavenging tailings are fed into a magnetic separator with a magnetic field strength of 220-350mT for weak magnetic roughing to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings. The weak magnetic roughing concentrate is then fed into a magnetic separator with a magnetic field strength of 160-220mT for weak magnetic cleaning to obtain weak magnetic cleaning concentrate and weak magnetic cleaning tailings. The weak magnetic cleaning concentrate is a magnetite concentrate product, and the weak magnetic cleaning tailings and weak magnetic roughing tailings are weak magnetic separation tailings.

[0026] Furthermore, the concentration of the overflow slurry in step (6) is 30%-32%; the gold and silver flotation operation includes a roughing stage, two cleaning stages and two scavenging stages. The roughing concentrate is processed by two cleaning stages to obtain a gold concentrate enriched with gold and silver. The tailings from the roughing tailings are processed by two scavenging stages and then used as the final flotation tailings for the gold and silver flotation operation, which are then used for the subsequent strong magnetic cleaning. The reagents added in the roughing stage include 50g / t-100g / t of ethylenediaminetetramethylphosphoric acid activator and 10g / t-15g / t of Z200 gold and silver collector. The reagents added in the two cleaning stages include 15g / t-20g / t of water glass. The reagents added in the two scavenging stages include 5g / t-10g / t of Z200. The magnetic field strength of the strong magnetic cleaning is 1.0-1.2T.

[0027] The purpose of the gold and silver flotation operation is to float gold and silver. The amount of reagent added for the cleaning and scavenging processes refers to the amount added in each cleaning and scavenging stage.

[0028] Furthermore, the magnetic field strength of the strong magnetic roughing siderite in step (5) is 1.2-1.5T.

[0029] Furthermore, the gangue minerals of the copper-sulfur-iron gold-silver ore are mainly quartz, carbonates and a small amount of aluminosilicates, with a gangue content of 40%-50%; Cu content of 0.2%-0.35%; Au content of 1.5g / t-2.5g / t; Ag content of 20g / t-35g / t; S content of 6%-8%; TFe content of 23%-33%; mFe content of 3%-5%; and SiD content of 20%-30%.

[0030] The beneficial effects of this invention are: This invention targets copper-sulfur-iron gold-silver ore and achieves efficient recovery of all valuable elements.

[0031] This invention achieves two-stage enrichment of copper through the synergistic effect of "grinding-flotation copper pre-enrichment" and "mid-ore fine grinding-copper secondary enrichment and sulfur pre-enrichment," minimizing the loss of gold, silver, and copper due to insufficient liberation or over-grinding caused by insufficient targeting in a single grinding process. It also avoids the problem of insufficient hydrophobicity of intergrowth minerals such as "copper-sulfur," "gold-sulfur," and "gold-gangue" in a single flotation process due to high-alkali inhibition and "strong suppression and pull," resulting in their inability to be effectively collected and floated by the collector, thus preventing loss. The synergy of these two processes maximizes the enrichment and recovery of gold and silver into the high-value copper concentrate.

[0032] By further enriching sulfur twice, the sulfur in the raw ore can be recovered to the maximum extent.

[0033] Finally, through the synergistic effect of "weak magnetic recovery of magnetite," "strong magnetic roughing of siderite," and "fine grinding-concentrate flotation-recovery of siderite concentrate," magnetite and siderite are separated while avoiding the loss of gold and silver contained in siderite due to incomplete liberation. Furthermore, the roughing of siderite results in insufficient liberation during grinding, leading to low-quality concentrate that fails to meet standards. Fine grinding allows for strong magnetic separation of qualified siderite products. This synergistic mechanism not only effectively recovers gold and silver from siderite to produce gold concentrate but also maximizes the quality of the siderite concentrate, achieving two goals at once. Attached Figure Description

[0034] Figure 1 This is the process flow diagram of the present invention (Part A); Figure 2 This is the process flow diagram of the present invention (Part B); Figure 3 This is the process flow diagram of the present invention (Part C). Detailed Implementation

[0035] To make the technical problems and solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0036] The specific process is as follows: Figure 1 , 2 As shown in Figure 3, where Figure 1 B in the middle indicates switching to Figure 2 , Figure 1 The "C" indicates that the process is transferred to... Figure 3 . Example 1

[0037] Raw ore: Copper-sulfur-iron gold-silver ore from a 6000t / d beneficiation plant in a mine in Yunnan Province. The composition and grade of the raw ore are as follows: aluminosilicate (clay minerals, chlorite, mica) 10.65%, carbonate (calcite, dolomite) 34.89%, Au 1.94g / t, Ag 31.50g / t, Cu 0.43%, S 7.63%, TFe 25.92%, mFe 4.67%.

[0038] (1) Grinding-flotation copper pre-enrichment: The raw ore is fed into a semi-autogenous mill, and then ground and classified by a ball mill and a hydrocyclone. Sodium sulfide 530g / t and lime 2100g / t are added to obtain a grinding and washing slurry with -200 mesh 81.68%, slurry concentration 33.5%, and pH 8.5. The grinding and washing slurry is fed into a flotation machine, and Z200 28g / t is added for copper roughing operation (two-stage roughing in this embodiment) to obtain copper roughing concentrate and copper roughing tailings. The copper roughing concentrate is fed into a flotation machine for copper cleaning operation (three-stage cleaning in this embodiment). The reagents added are lime 560g / t, sodium sulfite 260g / t and water glass 180g / t. After cleaning, copper middlings are obtained, and copper concentrate is pre-enriched.

[0039] (2) Fine grinding of middlings - secondary enrichment of copper and pre-enrichment of sulfur: The copper roughing tailings from step (1) are fed into a flotation machine with Z200 13g / t added for copper scavenging (two-stage scavenging in this embodiment) to obtain copper scavenging rough concentrate and copper scavenging tailings; the copper scavenging rough concentrate and the copper middlings from step (1) are finely ground and classified to obtain an overflow slurry with -400 mesh accounting for 92.3% and a concentration of 27%; the overflow slurry is then fed into a flotation machine for copper-sulfur separation roughing operation, with the addition of lime 590g / t, sodium humate 265g / t and Z200. 8 g / t is used to obtain copper-bearing concentrate and sulfur-bearing tailings from flotation. The copper-bearing concentrate is fed into the flotation machine and 510 g / t of lime and 235 g / t of sodium humate are added for three-stage cleaning to obtain secondary enriched copper concentrate. The final tailings after cleaning are returned to the copper-sulfur separation roughing operation. The sulfur-bearing tailings are added with 6 g / t of Z200 and scavenged for two-stage cleaning to obtain pre-enriched sulfur concentrate (the amount of reagent added refers to the amount added in each cleaning and scavenging stage). The final tailings after scavenging are returned to the copper-sulfur separation roughing operation.

[0040] (3) Secondary enrichment of sulfur: The copper scavenging tailings from step (2) are fed into the flotation machine and 238 g / t of butyl xanthate and 300 g / t of copper sulfate are added for sulfur roughing to obtain sulfur roughing concentrate and sulfur roughing tailings. The sulfur roughing concentrate is further enriched by adding 130 g / t of water glass for three stages of cleaning to obtain secondary enriched sulfur concentrate. The cleaned tailings are finally reintroduced into the sulfur roughing operation. The sulfur roughing tailings are further enriched by two stages of scavenging to obtain sulfur scavenging concentrate and sulfur scavenging tailings. The sulfur scavenging concentrate is finally returned to the sulfur roughing operation. In the first stage of scavenging, 135 g / t of butyl xanthate is added, and in the second stage of scavenging, 104 g / t of pentyl xanthate is added.

[0041] (4) Weak magnetic recovery of magnets: The sulfur scavenging tailings from step (3) are fed into a magnetic separator with a magnetic field strength of 350mT for weak magnetic roughing to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings; the weak magnetic roughing concentrate is then fed into a magnetic separator with a magnetic field strength of 220mT for weak magnetic fine selection to obtain weak magnetic fine concentrate and weak magnetic fine tailings. The weak magnetic fine concentrate is a magnet concentrate product, and the weak magnetic fine tailings and weak magnetic roughing tailings are weak magnetic separation tailings.

[0042] (5) Strong magnetic roughing of siderite: The weak magnetic separation tailings from step (4) are fed into a magnetic separator with a magnetic field strength of 1.2T for strong magnetic roughing of siderite to obtain siderite rough concentrate and strong magnetic roughing tailings.

[0043] (6) Fine grinding-flotation of gold and silver-recovery of siderite concentrate: The siderite rough concentrate from step (5) is fed into a tower mill for fine grinding and classification to obtain an overflow slurry with a -400 mesh content of 94% and a concentration of 30%. The overflow slurry is fed into a flotation machine for gold and silver flotation. In this embodiment, the gold and silver flotation operation consists of one roughing stage, two cleaning stages, and two scavenging stages. The roughing concentrate from the first stage is processed by two cleaning stages to obtain a gold concentrate enriched with gold and silver. The scavenging tailings from the roughing tailings from the first stage are fed into a magnetic separator with a magnetic field strength of 1.0T for strong magnetic cleaning to obtain siderite concentrate and strong magnetic cleaning tailings. In the first roughing stage, 87.6 g / t of ethylenediaminetetramethylphosphoric acid and 14 g / t of Z200 are added. In the two cleaning stages, 16 g / t of water glass is added. In the two scavenging stages, 8 g / t of Z200 is added.

[0044] The production indicators for the entire process are shown in Table 1.

[0045]

[0046] Example 2 Raw ore: Copper-sulfur-iron gold-silver ore from a mine in Yunnan Province. The composition and grade of the raw ore are as follows: aluminosilicate (clay minerals, chlorite, mica) 6.85%, carbonate (calcite, dolomite) 29.41%, Au 1.83g / t, Ag 25.50g / t, Cu 0.40%, S 8.15%, TFe 29.03%, mFe 6.70%.

[0047] (1) Grinding-flotation copper pre-enrichment: The raw ore is fed into a semi-autogenous mill, and then ground and classified by a ball mill and a hydrocyclone. Sodium sulfide 745 g / t and lime 2300 g / t are added to obtain a grinding and washing slurry with -200 mesh 82.32%, slurry concentration 34.4%, and pH 8.5. The grinding and washing slurry is fed into a flotation machine, and Z200 26 g / t is added for copper roughing operation (two-stage roughing in this embodiment) to obtain copper roughing concentrate and copper roughing tailings. The copper roughing concentrate is fed into a flotation machine for copper cleaning operation (three-stage cleaning in this embodiment). The reagents added are lime 610 g / t, sodium sulfite 293 g / t and water glass 220 g / t. After cleaning, copper middlings are obtained, and copper concentrate is pre-enriched.

[0048] (2) Fine grinding of middlings - secondary enrichment of copper and pre-enrichment of sulfur: The copper roughing tailings from step (1) are fed into a flotation machine with Z200 11g / t added for copper scavenging (two-stage scavenging in this embodiment) to obtain copper scavenging rough concentrate and copper scavenging tailings; the copper scavenging rough concentrate and the copper middlings from step (1) are finely ground and classified to obtain an overflow slurry with -400 mesh accounting for 92.6% and a concentration of 27%; the overflow slurry is then fed into a flotation machine for copper-sulfur separation roughing operation, with the addition of lime 590g / t, sodium humate 260g / t and Z200. 8 g / t is used to obtain copper-bearing concentrate and sulfur-bearing tailings from flotation. The copper-bearing concentrate is fed into the flotation machine and 580 g / t of lime and 250 g / t of sodium humate are added for three-stage cleaning to obtain secondary enriched copper concentrate. The final tailings after cleaning are returned to the copper-sulfur separation roughing operation. The sulfur-bearing tailings are added with 5 g / t of Z200 and scavenged for two-stage cleaning to obtain pre-enriched sulfur concentrate. The final tailings after scavenging are returned to the copper-sulfur separation roughing operation.

[0049] (3) Secondary enrichment of sulfur: The copper scavenging tailings from step (2) are fed into the flotation machine and 249 g / t of butyl xanthate and 350 g / t of copper sulfate are added for sulfur roughing to obtain sulfur roughing concentrate and sulfur roughing tailings. The sulfur roughing concentrate is further enriched by adding 150 g / t of water glass for three-stage cleaning to obtain secondary enriched sulfur concentrate. The cleaned tailings are finally reintroduced into the sulfur roughing operation. The sulfur roughing tailings are further enriched by two-stage scavenging to obtain sulfur scavenging concentrate and sulfur scavenging tailings. The sulfur scavenging concentrate is finally returned to the sulfur roughing operation. In the first stage of scavenging, 146 g / t of butyl xanthate is added, and in the second stage of scavenging, 127 g / t of pentyl xanthate is added.

[0050] (4) Weak magnetic recovery of magnets: The sulfur scavenging tailings from step (3) are fed into a magnetic separator with a magnetic field strength of 350mT for weak magnetic roughing to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings; the weak magnetic roughing concentrate is then fed into a magnetic separator with a magnetic field strength of 220mT for weak magnetic fine selection to obtain weak magnetic fine concentrate and weak magnetic fine tailings. The weak magnetic fine concentrate is a magnet concentrate product, and the weak magnetic fine tailings and weak magnetic roughing tailings are weak magnetic separation tailings.

[0051] (5) Strong magnetic roughing of siderite: The weak magnetic separation tailings from step (4) are fed into a magnetic separator with a magnetic field strength of 1.3T for strong magnetic roughing of siderite to obtain siderite concentrate and strong magnetic roughing tailings.

[0052] (6) Fine grinding-flotation of gold and silver-recovery of siderite concentrate: The siderite rough concentrate from step (5) is fed into a tower mill for fine grinding and classification to obtain an overflow slurry with a -400 mesh content of 93% and a concentration of 30%. The overflow slurry is fed into a flotation machine for gold and silver flotation. In this embodiment, the gold and silver flotation operation consists of one roughing stage, two cleaning stages, and two scavenging stages. The roughing concentrate from the first stage is processed by two cleaning stages to obtain a gold concentrate enriched with gold and silver. The scavenging tailings from the roughing tailings from the first stage are fed into a magnetic separator with a magnetic field strength of 1.1T for strong magnetic cleaning to obtain siderite concentrate and strong magnetic cleaning tailings. In the first roughing stage, 92.8 g / t of ethylenediaminetetramethylphosphoric acid and 12 g / t of Z200 are added. In the two cleaning stages, 18 g / t of water glass is added. In the two scavenging stages, 6 g / t of Z200 is added.

[0053] The production indicators for the entire process are shown in Table 2.

[0054]

[0055] Comparative Example Raw ore: Copper-sulfur-iron gold-silver ore from a 6000t / d beneficiation plant in a mine in Yunnan Province. The composition and grade of the raw ore are as follows: aluminosilicate (clay minerals, chlorite, mica) 10.80%, carbonate (calcite, dolomite) 36.56%, Au 2.10g / t, Ag 27.58g / t, Cu 0.46%, S 6.65%, TFe 27.40%, mFe 5.30%.

[0056] The traditional beneficiation process of "preferential copper flotation followed by sequential sulfur flotation" is used to process copper-sulfur-iron gold-silver ore. The specific steps are as follows: (1) Grinding-Preferred Copper Flotation: The raw ore is fed into a semi-autogenous mill, and then ground and classified by a ball mill and a hydrocyclone. 3550 g / t of lime is added to obtain a grinding and washing slurry with 93.1% of -200 mesh and pH 10. The grinding and washing slurry is then fed into a flotation machine for two-stage copper roughing and two-stage scavenging operations. 71.5 g / t of Z200 and 37 g / t of pine oil are added to obtain copper flotation tailings. The copper roughing concentrate is fed into a three-stage cleaning operation. 1070 g / t of lime is added to obtain copper flotation concentrate at pH 11. This step involves fine grinding of the ore, which leads to the weathering of rocks and weakly magnetic iron minerals becoming highly muddy in the slurry. This not only worsens the working environment for subsequent sulfur flotation, magnetite separation, and siderite separation, but also, under the high-alkali conditions of copper beneficiation, intergrowths such as copper-sulfur, gold-sulfur, and gold-gangue are strongly suppressed, making further separation and recovery impossible. Copper, gold, and silver are forced to be lost to other minerals or tailings, making efficient recovery difficult. (2) Sequential flotation: The copper flotation tailings from step (1) are fed into a flotation machine for two-stage roughing and two-stage scavenging operations. 610 g / t of concentrated sulfuric acid and 282 g / t of butyl xanthate are added to obtain sulfur flotation tailings. The sulfur flotation rough concentrate is fed into a flotation machine for three-stage cleaning operations to obtain sulfur concentrate. This step requires the addition of concentrated sulfuric acid to deeply activate the highly inhibited sulfur minerals. The large amount of calcium sulfate generated further mudsens the pulp viscosity, which deteriorates the recovery conditions of sulfur flotation and subsequent magnetic separation of iron minerals. (3) Two-stage weak magnetic recovery of magnetite: The sulfur flotation tailings from step (2) are fed into a magnetic separator with a magnetic field strength of 220mT for weak magnetic roughing to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings; the weak magnetic roughing concentrate is then fed into a magnetic separator with a magnetic field strength of 160mT for weak magnetic cleaning to obtain weak magnetic cleaning tailings, and the weak magnetic cleaning concentrate is magnetite concentrate product. The slurry fed into this step is in a highly muddy state due to the previous process, making it difficult to efficiently recover magnetic minerals. The magnetite concentrate has poor quality due to the mud adhering to its surface. The technical specifications for the entire process are shown in Table 3.

[0057]

[0058] Comparison of Example 1 and Comparative Example: Based on the comparison of production index data in Tables 1 and 3, Example 1 has the following significant improvements compared to the comparative example: 1. Overall improvement in performance indicators (1) Gold and silver recovery rates: The gold recovery rate increased from 86.67% to 91.24%, an increase of 4.57%; the silver recovery rate increased from 81.80% to 94.41%, an increase of 12.61%.

[0059] (3) Copper and sulfur recovery rates: The copper recovery rate increased from 87.39% to 94.65%, an increase of 7.26%; the sulfur recovery rate increased from 78.05% to 93.18%, an increase of 15.13%.

[0060] (3) Magnetite concentrate: The magnetite recovery rate increased from 44.53% to 90.36%, an increase of 45.83%; the TFe grade increased from 58.4% to 59.61%, an increase of 1.21%. (4) Siderite concentrate: Siderite recovery increased from no recovery to 63.59%, TFe grade 37.5%.

[0061] 2. The amount of tailings has decreased. Example 1 shows that the siderite recovered from the raw ore can be sold directly or used as raw material for further processing, which greatly reduces the amount of tailings and significantly reduces tailings management costs.

[0062] Comparison between Example 2 and the Comparative Example: Based on the comparison of production index data in Tables 2 and 3, Example 2 has the following significant improvements compared to the comparative example: 1. Overall improvement in performance indicators (1) Gold and silver recovery rates: The gold recovery rate increased from 86.67% to 90.16%, an increase of 3.49%; the silver recovery rate increased from 81.80% to 91.57%, an increase of 9.77%.

[0063] (3) Copper and sulfur recovery rates: The copper recovery rate increased from 87.39% to 93.00%, an increase of 5.61%; the sulfur recovery rate increased from 78.05% to 90.43%, an increase of 12.38%.

[0064] (3) Magnetite concentrate: The magnetite recovery rate increased from 44.53% to 89.10%, an increase of 44.57%; (4) Siderite concentrate: Siderite recovery increased from no recovery to 54.32%, TFe grade 36.60%.

[0065] 2. The amount of tailings has decreased. Example 2 shows that the siderite recovered from the raw ore can be sold directly or used as raw material for further processing, which greatly reduces the amount of tailings and significantly reduces tailings management costs.

[0066] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for processing copper-sulfur-iron gold-silver ore, characterized in that, Includes the following steps: (1) Grinding-flotation copper pre-enrichment: The copper-sulfur iron gold-silver ore is ground and classified, and sodium sulfide and lime are added to obtain a grinding and washing slurry with -200 mesh accounting for 80%-83% and pH 8.5-9.0; the grinding and washing slurry is fed into the flotation machine, and Z200 is added to carry out copper roughing operation to obtain copper roughing concentrate and copper roughing tailings; the copper roughing concentrate is fed into the flotation machine to carry out copper cleaning operation, and reagents including lime, sodium sulfite and water glass are added to obtain copper cleaning middlings after cleaning, and copper concentrate is pre-enriched. (2) Fine grinding of middlings - secondary enrichment of copper and pre-enrichment of sulfur: The copper roughing tailings from step (1) are fed into the flotation machine with Z200 for copper scavenging to obtain copper scavenging rough concentrate and copper scavenging tailings; the copper scavenging rough concentrate and the copper middlings from step (1) are finely ground and classified to obtain overflow slurry with -400 mesh accounting for 90%-93%; the overflow slurry is fed into the flotation machine for copper-sulfur separation roughing to float copper, gold and silver to obtain copper-containing flotation concentrate and sulfur-containing flotation tailings; the copper-containing flotation concentrate is further refined to obtain copper, gold and silver to obtain secondary enriched copper concentrate; the sulfur-containing flotation tailings are scavenged to obtain pyrite to obtain pre-enriched sulfur concentrate. (3) Secondary enrichment of sulfur: The copper scavenging tailings from step (2) are fed into a flotation machine for sulfur roughing operation, pyrite is floated to obtain sulfur roughing concentrate and sulfur roughing tailings. The sulfur roughing concentrate is further refined into pyrite to obtain secondary enriched sulfur concentrate. The refined tailings are finally reintroduced into the sulfur roughing operation. The sulfur roughing tailings are scavenged into pyrite to obtain sulfur scavenging concentrate and sulfur scavenging tailings. The sulfur scavenging concentrate is returned to the sulfur roughing operation. (4) Weak magnetic recovery of magnetite: The sulfur scavenging tailings from step (3) are fed into a magnetic separator for weak magnetic separation of magnetite to obtain magnetite concentrate and weak magnetic separation tailings; (5) Strong magnetic roughing of siderite: The weak magnetic separation tailings from step (4) are subjected to strong magnetic roughing of siderite to obtain siderite concentrate and strong magnetic roughing tailings. (6) Fine grinding-flotation of gold and silver-recovery of siderite concentrate: The siderite rough concentrate from step (5) is finely ground and classified to obtain an overflow slurry with a -400 mesh content of 92%-95%; the overflow slurry is fed into a flotation machine for gold and silver flotation, gold and silver are floated, the flotation concentrate is gold concentrate, and the flotation tailings are fed into a magnetic separator for strong magnetic separation of siderite to obtain siderite concentrate and strong magnetic separation tailings.

2. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (1), the copper roughing operation consists of two stages, and the copper cleaning operation consists of three stages.

3. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: After grinding and classifying the ore in step (1), 500g / t-800g / t of sodium sulfide and 2000g / t-2500g / t of lime are added to obtain the grinding and washing slurry; in the copper roughing operation, the amount of Z200 added is 20g / t-30g / t; the flotation reagents added in the copper cleaning operation include 500g / t-1000g / t of lime, 200g / t-300g / t of sodium sulfite and 150g / t-250g / t of water glass.

4. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: The concentration of the grinding slurry in step (1) is 32%-35%, the concentration of the overflow slurry in step (2) is 25%-28%, and the concentration of the overflow slurry in step (6) is 30%-32%.

5. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (2), the amount of Z200 added in the copper scavenging operation is 10g / t-15g / t; the flotation reagents added in the copper-sulfur separation roughing operation include 500g / t-800g / t of lime, 250g / t-300g / t of sodium humate and 5g / t-10g / t of Z200; the flotation reagents added when the copper concentrate is flotated include 300g / t-600g / t of lime and 220g / t-260g / t of sodium humate; and the flotation reagents added when the sulfur tailings are flotated include 5g / t-10g / t of Z200.

6. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (3), the sulfur roughing tailings scavenging is carried out in two stages. The reagents added in the first stage of scavenging include 120g / t-150g / t of butyl xanthate, and the reagents added in the second stage of scavenging include 100g / t-130g / t of pentyl xanthate.

7. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (3), the flotation reagents added to the sulfur roughing operation include 220g / t-260g / t of butyl xanthate and 250g / t-350g / t of copper sulfate. When the sulfur roughing concentrate is cleaned, the flotation reagents added include 120g / t-150g / t of water glass.

8. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (4), the weak magnetic separation is a two-stage weak magnetic separation. The sulfur scavenging tailings are fed into a magnetic separator with a magnetic field strength of 220-350mT for weak magnetic roughing to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings. The weak magnetic roughing concentrate is then fed into a magnetic separator with a magnetic field strength of 160-220mT for weak magnetic cleaning to obtain weak magnetic cleaning concentrate and weak magnetic cleaning tailings. The weak magnetic cleaning concentrate is a magnetite concentrate product, and the weak magnetic cleaning tailings and weak magnetic roughing tailings are weak magnetic separation tailings.

9. The method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (5), the magnetic field strength of the strong magnetic roughing siderite is 1.2-1.5T.

10. A method for processing copper-sulfur-iron gold-silver ore according to claim 1, characterized in that: In step (6), the concentration of the overflow slurry is 30%-32%; the gold and silver flotation operation includes a roughing stage, two cleaning stages and two scavenging stages. The roughing concentrate is processed by two cleaning stages to obtain a gold concentrate enriched with gold and silver. The tailings from the roughing tailings are processed by two scavenging stages and then used as the final flotation tailings for the gold and silver flotation operation, which are then used for the subsequent strong magnetic cleaning. The reagents added in the roughing stage include 50g / t-100g / t of ethylenediaminetetramethylphosphoric acid and 10g / t-15g / t of Z200. The reagents added in the two cleaning stages include 15g / t-20g / t of water glass. The reagents added in the two scavenging stages include 5g / t-10g / t of Z200. The magnetic field strength of the strong magnetic cleaning is 1.0-1.2T.

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