A method for beneficiating copper-containing high-sulfur magnetite ore

Abstract

The present application discloses a beneficiation method for copper-containing high-sulfur magnetite ore, which relates to the field of mineral processing technology. The specific steps include: S1, crushing pre-selection to remove large particles; S2, magnetic separation stage to strengthen separation of iron concentrate; S3, pre-treatment of the undersize product in step S1 and the magnetic separation tailings in S2 using sodium silicate-polyepoxysuccinic acid modification; sodium silicate-polyepoxysuccinic acid is a composite of sodium silicate and polyepoxysuccinic acid, with the addition amount of PESA being 0.2-0.4 kg / t; sodium silicate modulus 2.8-3.2, Na2O content ≥8.5%, SiO2 content ≥26.5%; addition amount is 1.2-2.5 kg / t; S4, concentration desliming-flotation combined to obtain a copper-sulfur mixed concentrate; S5, copper-sulfur separation. This method can achieve better sorting effect and increase the yield of high-grade copper.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and in particular to a mineral processing method for copper-containing high-sulfur magnetite ore. Background Art

[0002] Ore dressing is a process of crushing and grinding the ore according to the physical and chemical properties of different minerals in the ore, and then using gravity separation, flotation, magnetic separation, electrostatic separation and other methods to separate useful minerals from gangue minerals, and to separate various symbiotic (associated) useful minerals from each other as much as possible, remove or reduce harmful impurities, and obtain raw materials required for smelting or other industries.

[0003] Minerals are categorized as strongly magnetic, weakly magnetic, and non-magnetic. Magnetic separation is a mineral processing method that separates minerals in an inhomogeneous magnetic field based on the magnetic differences among the minerals within the ore. Magnetic separation is primarily used for magnetic ferrous oxide minerals, such as magnetite, vanadium-titanium magnetite, hematite, and ilmenite, and is also used for the separation of pyrrhotite. Iron ore is primarily magnetite, accompanied by small amounts of chalcopyrite and pyrite, which can be recycled. Due to its low copper grade, copper recovery is often not considered during the mining process, resulting in significant waste of copper resources.

[0004] For example, the Chinese patent application number CN202110554147.5 is a beneficiation method for copper-containing high-sulfur magnetite ore, which is used for the beneficiation of copper-containing high-sulfur magnetite with an original ore iron grade between 30%-40%, a sulfur content between 1.5%-3.0%, and a copper grade between 0.04%-0.10%. Through surface chemical regulation of concentration and desliming, the ultrafine ore slime has a high specific surface area, preferentially adsorbs the collector AT-608, and forms a "reagent shielding layer". After removing the ore slime below 20μm, the amount of flotation reagent is reduced, and the copper recovery rate is improved; this invention reduces the amount of ore entering the mill and the energy consumption of grinding while reducing the loss of valuable elements such as copper and sulfur, eliminates the adverse effects of coarse-grained tailings on the flotation pressure tank and fine-grained tailings on the reagent consumption of mixed flotation and the difficulty of copper-sulfur concentrate to meet the standards, and solves the problem of poor slurry fluidity caused by ultrafine particle size to increase the tailings filling concentration.

[0005] However, when the particle size of the mineral embedding increases, the proportion of sulfur-copper minerals in the coarse-grained fraction increases, and the slag screen cannot effectively intercept it, which will eventually result in waste of sulfur-copper. Summary of the Invention

[0006] The embodiment of the present application solves the problem in the prior art that the mineral embedding particle size increases, resulting in an increase in the proportion of sulfur-copper minerals in the coarse particle size and waste of sulfur-copper minerals, by providing a beneficiation method for copper-containing high-sulfur magnetite ore, thereby achieving better sorting effect.

[0007] The present invention provides a method for beneficiating copper-containing high-sulfur magnetite ore, which comprises the following steps:

[0008] S1, crushing and pre-selection to remove large particles;

[0009] S2, magnetic separation section to enhance separation of iron concentrate;

[0010] S3, modifying and pre-treating the undersize product in step S1 and the magnetic separation tailings in S2 using sodium silicate-polyepoxysuccinic acid (PESA);

[0011] Sodium silicate-polyepoxysuccinic acid is a mixture of sodium silicate and polyepoxysuccinic acid (PESA), with a PESA addition amount of 0.2-0.4 kg / t; the sodium silicate modulus is 2.8-3.2, the Na2O content is ≥8.5%, and the SiO2 content is ≥26.5%; the addition amount is 1.2-2.5 kg / t;

[0012] S4, concentration and desliming combined with flotation to obtain copper-sulfur mixed concentrate;

[0013] S5. Copper and sulfur separation.

[0014] Furthermore, it is used for beneficiation of copper-containing high-sulfur magnetite ore with an original ore iron grade of 40%-52%, a sulfur grade of 1.4%-2.8%, and a copper grade of 3.2%-5.8%.

[0015] Furthermore, the pH condition of the sodium silicate-polyepoxysuccinic acid modification pretreatment is 4.5-9.5.

[0016] Furthermore, the sodium silicate-polyepoxysuccinic acid modification pretreatment includes two ion selections, and the ions are calcium ions and aluminum ions commonly used in mineral processing.

[0017] Furthermore, the first ion selection is specifically as follows: after adjusting the pH in the stirring tank to 4.5 using sulfuric acid, reacting for 8-12 minutes, and then adding 5g / t of APAM.

[0018] Furthermore, in the first ion selection, the pH in the stirring tank is adjusted to 5 using sulfuric acid, reacted for 8-12 minutes, and low modulus sodium silicate and short-chain PESA are added.

[0019] Furthermore, after the first ion selection, the pH of the liquid is adjusted to 7.5 using lime milk, and a collector is added.

[0020] Furthermore, in the second ion selection, the pH is adjusted to 9.5 using lime milk, and then high modulus sodium silicate and long-chain PESA are added.

[0021] Furthermore, the modulus of low modulus sodium silicate is 2.8, and the chain length of short chain PESA is 3000-5000.

[0022] Furthermore, the modulus of high modulus sodium silicate is 3.2, and the chain length of long-chain PESA is 8000-12000.

[0023] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0024] First, sodium silicate preferentially adsorbs on the surface of fine mud to form a hydrophilic film, reducing the coverage of fine mud on chalcopyrite; sodium silicate disperses fine mud in the slurry, reduces viscosity, improves bubble-mineral collision efficiency, and promotes sorting; sodium silicate promotes the removal of ultrafine mud, reduces the yield stress of the filling body, and inhibits the ineffective adsorption of fine mud on the collector (AT-608), releasing the active sites of the agent and increasing the effect of the collector.

[0025] Secondly, through the synergistic effect of PESA and sodium silicate, a molecular-level hard water barrier is formed to form a core-shell structure, and wettability is regulated to promote separation, and rheological-adsorption synergistic enhancement is utilized; the chelating function of PESA (anti-Ca 2+ ) complements the electrostatic regulation (dissociation enhancement) of sodium silicate to form a "chelation-dispersion-hydrophobic" trinity mechanism; through the targeted modification of the chalcopyrite surface by epoxy groups, differential desorption of sulfides is achieved; double dispersion reduces the slurry viscosity to 45mPa·s, making the flotation rate constant k exceed 2.3min -1 , reaching the efficient sorting threshold.

[0026] Third, Al was preferentially precipitated by staged pH control (4.5→9.5). 3+ (forming crystalline Al(OH)3), eliminating excess Al 3+ The competitive consumption of PESA, and then the PESA and sodium silicate are used under alkaline conditions to form a hard water resistant core-shell structure with PESA, further chelating the residual Ca 2+ , to prevent it from forming CaSiO3 precipitation with sodium silicate.

[0027] Fourthly, by combining sodium silicate with different moduli and PESA with different chain lengths, the coarse-grained fraction can be targetedly dissociated, the fine-grained fraction can be deeply sorted, the anti-interference ability can be improved, and higher-grade copper ore can be obtained. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains; the terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0029] It should be noted that the units kg / t and g / t represent the mass ratio of a certain component to the entire material to be processed. When the material to be processed is raw ore, kg / t (g / t) indicates the amount of a certain component added per ton of raw ore. When the material to be processed is slurry, kg / t (g / t) indicates the amount of a certain component added per ton of slurry. When the material to be processed is mixed concentrate, kg / t (g / t) indicates the amount of a certain component added per ton of mixed concentrate.

[0030] Example 1: The present application provides a beneficiation method for copper-containing high-sulfur magnetite ore, which is used to beneficiate copper-containing high-sulfur magnetite ore with an iron grade of 40%-52%, a sulfur grade of 1.4%-2.8%, and a copper grade of 3.2%-5.8%.

[0031] S1, crushing and pre-selection: the raw ore is crushed to 12mm, and the tailings are discarded by gravity magnetic pre-selection. The pre-selected tailings are graded by a 1mm linear screen, and the oversize product (7-10%) is used as building materials; the undersize product is combined with the tailings from subsequent weak magnetic separation and enters S3 pretreatment;

[0032] S2, magnetic separation stage strengthening: the pre-selected coarse concentrate is subjected to two-stage magnetic grinding (the first stage is ground to 200 mesh 55%, the second stage is ground to 200 mesh 75%),

[0033] Three weak magnetic separations (magnetic field strength 0.20T) were performed to obtain iron concentrate (TFe ≥ 65%);

[0034] S3, sodium silicate modification pretreatment: The undersize product in S1 and the magnetic separation tailings in S2 (containing 3.2%-5.8% Cu and 1.4%-2.8%) enter a Φ6m stirring tank, where sodium silicate solution is added and lime is added to adjust the pH to 9.5. The slurry is then passed through a linear vibrating screen (1mm) to intercept the coarse residue.

[0035] The sodium silicate modulus is 2.8-3.2, the Na2O content is ≥8.5%, and the SiO2 content is ≥26.5%; the addition amount is 1.2-2.5 kg / t. It should be noted that the unit kg / t used in this step represents the addition amount per ton of raw ore. The sodium silicate addition amount of 1.2-2.5 kg / t means that 1.2-2.5 kg of sodium silicate is added per ton of raw ore.

[0036] S4, concentration and desliming-flotation combination: the undersize pulp enters a high-efficiency thickener (with 15g / t APAM added), and the underflow enters a flotation machine for primary roughing, primary cleaning, and secondary scavenging. AT-608 is used as a collector and 2# oil is used as a frother. The AT-608 dosage is 60g / t and the frother 2# oil dosage is 25g / t. The dosage of the primary scavenging agent is 30g / t AT-608 and 15g / t 2# oil. The dosage of the secondary scavenging agent is 30g / t AT-608 and 15g / t 2# oil. A copper-sulfur mixed concentrate (Cu: 8.9-12.2%, S: 5.6-9.1%) is obtained. The unit g / t in this step represents the addition amount per ton of pulp. The AT-608 dosage of 60g / t means that 60g AT-608 is added per ton of pulp.

[0037] S5. Copper-sulfur separation: The mixed concentrate is re-ground to 85% of 200 mesh, and lime is added to suppress pyrite. The copper concentrate (Cu ≥ 19%, S ≤ 25%) and the sulfur concentrate (S ≥ 45%) are separated, which is divided into primary roughing, secondary cleaning, and secondary scavenging. The lime dosage is: 3000g / t for roughing, 1500g / t for primary cleaning, 750g / t for secondary cleaning, 1500g / t for primary scavenging, and 1500g / t for secondary scavenging. The unit g / t in this step represents the amount added per ton of mixed concentrate. The lime dosage of 3000g / t means that 3000g of lime is added to each ton of mixed concentrate.

[0038] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0039] SiO(OH) generated by hydrolysis of sodium silicate 3- The Zeta potential of the sulfide-copper mineral surface changes from -25mV to -40mV, and the negative charge on the quartz surface decreases (Zeta from -15 to -10 mV), resulting in an increase in the electrostatic repulsion between chalcopyrite and quartz (ΔZeta = 30 mV). This promotes the dissociation of coarse-grained inclusions and increases the degree of dissociation. Coarse-grained conjoined bodies (chalcopyrite-quartz) that were not completely dissociated during the grinding stage undergo secondary dissociation due to surface charge repulsion, reducing the proportion of sulfide-copper in the coarse fraction (+1mm). Sodium silicate (particle size 2-5nm) forms an adsorption layer on the mineral surface, preventing the physical inclusion of sulfide-copper minerals and gangue in the coarse fraction through steric hindrance.

[0040] Sodium silicate preferentially adsorbs on the surface of fine mud to form a hydrophilic film, reducing the coverage of fine mud on chalcopyrite; sodium silicate disperses fine mud in the slurry, reduces viscosity, improves bubble-mineral collision efficiency, and promotes sorting; sodium silicate promotes the removal of ultrafine mud, reduces the yield stress of the filling body, and inhibits the ineffective adsorption of fine mud on the collector (AT-608), releasing the active sites of the agent and increasing the effect of the collector.

[0041] In the group experiment, the iron grade of the raw ore in the experiment was 40%, the sulfur grade was 2.2%, and the copper grade was 4.6%; the groups are shown in Table 1;

[0042] Table 1

[0043]

[0044] Zeta potential and surface charge analysis were performed using a Zeta potential meter (Malvern Zetasizer Nano) to measure the surface potential of the minerals. The experimental results are shown in Table 2.

[0045] Table 2

[0046]

[0047] Flotation kinetics tests were conducted in a 1.5 L flotation cell. Both the control and experimental groups (1.8 kg / t sodium silicate) maintained a pH of 9.5 (adjusted with lime) and used 80 g / t of AT-608. The copper recovery rates at different time points (0-5 min) were recorded, and the flotation rate constant (k value) was fitted. The results are shown in Table 3.

[0048] Table 3

[0049]

[0050] The +1 mm coarse fraction was separated by sieving, and the degree of dissociation of the copper sulfide mineral monomer was determined by MLA (mineral dissociation analyzer). The results are shown in Table 4.

[0051] Table 4

[0052]

[0053] Example 2: The above embodiment solves the problems of insufficient dissociation of coarse particles, severe interference of fine mud, and poor flotation dynamics through the charge regulation and dispersion of sodium silicate. However, in the water, Ca 2+ / Mg 2+ When the concentration is greater than 200 mg / L, sodium silicate (SiO(OH) 3- ) and Ca 2+ The reaction generates CaSiO3 precipitation, which causes the surface of the copper sulfide mineral to be covered, affecting the effect of the sodium silicate. In this regard, further improvements are made based on Example 1.

[0054] In step S3, sodium silicate modification pretreatment, sodium silicate is compounded with polyepoxysuccinic acid (PESA) and the amount of PESA added is 0.2-0.4 kg / t; that is, 0.2-0.4 t of PESA is added to each ton of raw ore.

[0055] Sodium silicate and polyepoxysuccinic acid are premixed and stirred evenly before being added into the stirring tank.

[0056] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0057] The synergistic effect of PESA and sodium silicate forms a molecular-level anti-hard water barrier to form a core-shell structure, and regulates wettability, promotes separation, and utilizes rheological-adsorption synergistic enhancement; the chelating function of PESA (anti-Ca 2+ ) complements the electrostatic regulation (dissociation enhancement) of sodium silicate to form a "chelation-dispersion-hydrophobic" trinity mechanism; through the targeted modification of the chalcopyrite surface by epoxy groups, differential desorption of sulfides is achieved; double dispersion reduces the slurry viscosity to 45mPa·s, making the flotation rate constant k exceed 2.3min -1 , reaching the efficient sorting threshold.

[0058] The chemical formula of PESA is (C3H4O4) n The main chain is epoxysuccinic acid repeating unit, containing epoxy group (-O-) and carboxylic acid group (-COOH). Carboxylic acid group: through ionic bond (-COO - …Ca 2+ ) Chelates Ca in water 2+ , forming a stable five-membered ring complex (bond energy ≈ 200 kJ / mol); the epoxy group provides flexibility to the molecular chain and combines with the silanol (Si-OH) of sodium silicate through hydrogen bonds (-O-…HO-Si).

[0059] The carboxylic acid group of PESA and the SiO(OH) 3- Through hydrogen bond-ionic bond hybridization, COO is formed - ...HO-Si bridging structure; the oxygen atom of the epoxy group forms an OHO hydrogen bond with the hydrogen of the silanol group (bond length ≈ 1.8Å, bond energy ≈ 25 kJ / mol); the flexible long chain of PESA (molecular weight 2000-5000) wraps the sodium silicate colloidal particles (particle size 2-5nm), forming a core-shell structure, which prevents Ca 2+ Contact with sodium silicate active sites.

[0060] PESA and sodium silicate form a three-dimensional network structure through hydrophobic interaction and electrostatic complementarity: the hydrophobic chain segment (epoxy region) of PESA is bound to the hydrophobic surface (Si-O-Si) of sodium silicate through van der Waals force (≈5 kJ / mol); the electrostatic attraction between carboxylic acid groups and silanol groups (≈15 kJ / mol) maintains structural stability, allowing PESA and sodium silicate to self-assemble; the complex covers the surface of sulfide copper minerals (chalcopyrite, pyrite) through multi-point anchoring (each molecule contains 3-5 adsorption points), increasing the adsorption energy density; the three-dimensional network of the PESA-sodium silicate complex forms a shear-thinning structure in the slurry; the network is cross-linked at rest (viscosity ≈150 mPa·s), preventing particle sedimentation; under high shear force (G>300s -1 ) network dissociation (viscosity ≈ 50 mPa·s), improving the bubble-mineral collision efficiency.

[0061] The epoxy region of PESA is hydrophobic, while the carboxylic acid region is hydrophilic, which synergizes with the charge regulation of sodium silicate to achieve sorting selectivity, allowing the complex to form hydrophilic-hydrophobic alternating microregions on the chalcopyrite surface, while the pyrite surface remains uniformly hydrophilic.

[0062] PESA chelates 90% of Ca 2+ (complexation constant logK = 8.2), the remaining Ca 2+ Physically shielded by the sodium silicate-PESA core-shell structure; Ca 2+ The concentration tolerance was increased from 210 mg / L (single sodium silicate) to 830 mg / L (PESA-sodium silicate).

[0063] The flexible chains of PESA compensate for the brittleness of the rigid structure of sodium silicate, forming an adaptive adsorption layer on the mineral surface, which increases the resistance to mechanical shearing and stripping by 3 times; the complex reduces the adhesion energy barrier between sulfide copper minerals and bubbles (from 50 kT→25 kT), and the mineralization rate increases by 2 times.

[0064] A grouping experiment was conducted on Example 2. The raw ore in the experiment had an iron grade of 47%, a sulfur grade of 2.8%, and a copper grade of 3.4%. The groups are shown in Table 5.

[0065] Table 5

[0066]

[0067] The surface Zeta potential and adsorption amount of chalcopyrite were measured, and the results are shown in Table 6;

[0068] Table 6

[0069]

[0070] The wettability differences between chalcopyrite and pyrite at different PESA dosages were analyzed using a contact angle meter; the results are shown in Table 7;

[0071] Table 7

[0072]

[0073] Measure the viscosity of the slurry using a viscometer at different PESA dosages (GB10247-88, shear rate 100s -1 ) and bubble mineralization frequency (high-speed camera), the results are shown in Table 8;

[0074] Table 8

[0075]

[0076] The copper recovery was finally tested, and the results are shown in Table 9;

[0077] Table 9

[0078]

[0079] Example 3: Example 2 uses the synergistic effect of PESA and sodium silicate to form a molecular-level anti-hard water barrier to form a core-shell structure, and regulates wettability to promote separation. The rheological-adsorption synergistic effect is used to solve the problem of Ca 2+ The reaction generates CaSiO3 precipitation, which causes the surface of sulfide copper minerals to cover and affect the effect of sodium silicate. However, in high hardness water, polyvalent cations (Ca 2+ +Al 3+ ) coexistence, Al 3+ It preferentially forms an Al-PESA complex with PESA (stable constant logK = 12.5), which consumes the chelating capacity of PESA and the residual Ca 2+ CaSiO3 precipitation is still generated with sodium silicate. In order to solve the problem of reduced effect of sodium silicate caused by a large amount of metal ions, further improvements are made on the basis of Example 2.

[0080] In step S3, sodium silicate modification pretreatment, the magnetic separation tailings enter the stirring tank and undergo two ion selections;

[0081] First, perform the first ion selection, then adjust the pH in the stirring tank to 4.5 with sulfuric acid, and react at 25°C for 8-12 minutes (stirring intensity: 200s -1 ), then add APAM 5g / t, separate the solid and liquid, remove some aluminum ions, and perform the second ion selection of the liquid. Use lime milk to adjust the pH to 9.5, and then add the mixture of sodium silicate and polyepoxysuccinic acid for 300s. -1 Stir for 5-8 minutes to remove some calcium ions.

[0082] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0083] Preferential precipitation of Al by stepwise pH control (4.5→9.5) 3+ (forming crystalline Al(OH)3), eliminating excess Al 3+ The competitive consumption of PESA, and then the PESA and sodium silicate are used under alkaline conditions to form a hard water resistant core-shell structure with PESA, further chelating the residual Ca 2+ , to prevent it from forming CaSiO3 precipitation with sodium silicate.

[0084] Al 3+ With Ca 2+ Step-by-step treatment to avoid competitive complexation, suitable for beneficiation processes with high hardness water or high free metal ions, and step-by-step removal of Al 3+ After that, PESA effectively chelates Ca 2+ , avoid Al 3+ Excessive addition of reagents caused by competition can avoid the precipitation of CaSiO3, reduce the loss of sodium silicate, and lower the processing cost per ton of ore.

[0085] Through group experiments, further experiments were conducted on the basis of Experiment 5 to test the effect of segmented pH regulation. 3+ The removal results are shown in Table 10.

[0086] Table 10

[0087]

[0088] The beneficiation results are shown in Table 11;

[0089] Table 11

[0090]

[0091] Example 4: Example 3 achieves copper recovery rate in a complex system of multivalent cations through chemical removal priority reconstruction and process spatiotemporal decoupling, solving the problem of competition among multiple metal ions. In actual use, it is found that although metal ions will cause the effect of sodium silicate to decrease, they can enhance the separation of pyrite and chalcopyrite. Therefore, in order to improve its practical application capability, further improvements are made on the basis of Example 3.

[0092] For the first ion selection, adjust the pH in the stirred tank to 5 with sulfuric acid and react at 25°C for 8-12 minutes (stirring intensity: 200s -1), and add sodium silicate with a modulus of 2.8 at a dosage of 0.5kg / t, short-chain PESA (3000-5000) at a dosage of 0.2kg / t, solid-liquid separation, remove part of the aluminum ions, adjust the pH of the liquid to 7.5 with lime milk, add 30g / t of collector (AT-608), then perform a second ion selection, continue to adjust the pH to 9.5 with lime milk, add sodium silicate with a modulus of 3.2 at a dosage of 1.2kg / t, long-chain PESA (8000-12000) at a dosage of 0.3kg / t, and the temperature is 40-45℃.

[0093] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0094] By combining sodium silicate with different moduli and PESA with different chain lengths, it is possible to achieve targeted dissociation of the coarse particle size, deep separation of the fine particle size, improve anti-interference ability, and obtain higher-grade copper ore.

[0095] Low modulus sodium silicate quickly disperses coarse-grained slurry, and PESA short chains preferentially chelate Al 3+ , releasing active sites on the surface of sulfide copper minerals. Low modulus sodium silicate (SiO2 / Na2O≈2.8) hydrolyzes under weak acidic conditions (pH=5) to produce more oligomeric silicic acid (Si2O5 2- ), through electrostatic adsorption with Al 3+ Forming Al-Si complex (AlO6-Si2O5), accelerating Al(OH)3 precipitation;

[0096] High modulus sodium silicate forms a dense hydrophilic film to inhibit pyrite and hydrolyzes under strong alkaline conditions to generate more SiO(OH)3 - , enhance the negative charge on the mineral surface, further expand the potential difference with the gangue to separate the sulfide copper, and the long-chain PESA deeply chelates the residual Ca 2+ A more stable Ca-PESA complex is formed, and the flexible structure of the long chain enhances the steric hindrance, preventing Ca 2+ Contact sodium silicate; in the first ion selection, low modulus sodium silicate and short-chain PESA are used to preferentially dissociate coarse-grained copper sulfide minerals through high dispersibility and rapid chelation. The second ion selection uses high modulus sodium silicate and long-chain PESA to block the heterogeneous aggregation of fine-grained pyrite and chalcopyrite through strong inhibition and long-term chelation.

[0097] Although, in Ca 2+ +Al 3+ The flotation of sulfide copper ore will be difficult under the influence of Ca 2+ As an activator, it can selectively activate the chalcopyrite surface and enhance its hydrophobicity. Under neutral conditions, Ca 2+Combined with the Fe site on the surface of chalcopyrite, the Cu-S hydrophobic active site is exposed, and the adsorption efficiency of the collector is enhanced; at high pH, the residual Ca 2+ Form CaSiO3 colloid with sodium silicate to encapsulate gangue minerals; Al 3+ Forms a stable complex with PESA to enhance slurry dispersion, Al 3+ As an inhibitor, it can inhibit pyrite and gangue minerals through hydroxyl complexes. Under weak acidic conditions, Al 3+ Producing Al(OH)2 + and Al(OH)4 - Complexes such as chalcopyrite and pyrite are preferentially adsorbed on the surface of pyrite and quartz to form a hydrophilic layer; thus, in the presence of a large number of ions, chalcopyrite and pyrite can be separated, thereby obtaining a higher grade copper concentrate.

[0098] The copper recovery rate in Example 4 was tested on the basis of Example 3, and the results are shown in Table 12.

[0099] Table 12

[0100]

[0101] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and variations are readily apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A beneficiation method for copper-containing high-sulfur magnetite ore, characterized in that: The specific steps include: S1, crushing and pre-selection to remove large particles; S2, magnetic separation section to enhance separation of iron concentrate; S3, the undersize product of step S1 and the magnetic tailings in S2 are pretreated with sodium silicate-polyepoxysuccinic acid modification; in the sodium silicate-polyepoxysuccinic acid modification pretreatment, the magnetic tailings are subjected to two ion selections after entering the stirring tank; First ion selection: The pH in the stirring tank is adjusted to 5 with sulfuric acid, reacted at 25°C for 8-12 minutes, and sodium silicate with a modulus of 2.8 is added at a dosage of 0.5 kg / t and short-chain PESA at a dosage of 0.2 kg / t. Solid-liquid separation is performed to remove some aluminum ions. The liquid is adjusted to pH 7.5 with lime milk, and a collector is added at a dosage of 30 g / t. Then, the second particle selection is performed. Perform the second ion selection: continue to adjust the pH to 9.5 with lime milk, add sodium silicate with a modulus of 3.2 at a dosage of 1.2 kg / t and long-chain PESA at a dosage of 0.3 kg / t, and the temperature is 40-45°C; S4, concentration and desliming combined with flotation to obtain copper-sulfur mixed concentrate; S5. Copper and sulfur separation.

2. The beneficiation method of a copper-containing high-sulfur magnetite ore according to claim 1, characterized in that: It is used for the beneficiation of copper-containing high-sulfur magnetite ores with an iron grade of 40%-52%, a sulfur grade of 1.4%-2.8%, and a copper grade of 3.2%-5.8%.

3. The beneficiation method of a copper-containing high-sulfur magnetite ore according to claim 1, characterized in that: The pH condition of sodium silicate-polyepoxysuccinic acid modification pretreatment is 4.5-9.

5.

4. The beneficiation method of a copper-containing high-sulfur magnetite ore according to claim 1, characterized in that: The modulus of low modulus sodium silicate is 2.8, and the chain length of short chain sodium silicate-polyepoxysuccinic acid is 3000-5000.

5. The beneficiation method of a copper-containing high-sulfur magnetite ore according to claim 1, characterized in that: The modulus of high modulus sodium silicate is 3.2, and the chain length of long chain sodium silicate-polyepoxysuccinic acid is 8000-12000.

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