High-sulfur copper-bearing magnetite beneficiation method combined with magnetic suspension

Abstract

The application provides a high-sulfur copper-containing magnetite beneficiation method combined with magnetic suspension, which comprises the following steps: after high-sulfur copper-containing magnetite is crushed, wet grinding and water slurry adjustment are performed to form a first ore slurry; copper-sulfur floatation treatment is performed on the first ore slurry to obtain copper concentrate, sulfur concentrate and copper tailings; magnetic separation is performed on the copper tailings to obtain magnetic concentrate and tailings; demagnetization treatment is performed on the magnetic concentrate, water slurry adjustment is performed to form a second ore slurry, and then the second ore slurry is subjected to intensified desulfurization treatment to obtain sulfur concentrate and desulfurization tailings; and finally, two times of magnetic separation concentration treatment is performed on the desulfurization tailings to obtain iron concentrate and tailings. Through the above method, the iron, sulfur and copper elements in the raw ore can be effectively recovered by the organic combination of the four stages of copper-sulfur floatation-magnetic separation-intensified desulfurization-magnetic separation, so that the iron concentrate with sulfur content lower than 0.3% and iron grade higher than 65.5%, qualified sulfur concentrate and copper concentrate products are obtained.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a magnetic levitation combined method for beneficiating high-sulfur copper-bearing magnetite. Background Technology

[0002] Producing high-quality magnetite products has always been a relentless pursuit of China's iron ore beneficiation industry. Sulfur content is one of the important indicators for measuring the quality of iron concentrate. According to the requirements of steelmaking, for every 0.1% increase in sulfur content in iron ore, the coke ratio increases by about 5%, which has a significant negative impact on blast furnace ironmaking. Furthermore, the flue gas produced during the smelting process is rich in sulfides, increasing the environmental governance pressure on enterprises. Under the background of "green economy," researching ways to improve the comprehensive utilization level of copper-containing high-sulfur magnetite resources, achieving an iron grade of over 65% in the iron concentrate while reducing the sulfur content in the iron concentrate to below 0.3%, and recovering associated copper and sulfur valuable elements from the raw ore, has significant practical implications.

[0003] Since the sulfur in copper-containing high-sulfur magnetite is mainly found in sulfide minerals such as pyrrhotite, pyrite, and chalcopyrite, fully liberated pyrite and chalcopyrite, which have low specific magnetic coefficients, can be separated from magnetite by single magnetic separation or flotation. However, the sulfur in pyrrhotite, which has a high specific magnetic coefficient, cannot be separated from magnetite by single magnetic separation. Furthermore, pyrrhotite is prone to mud formation and oxidation. The oxidation rate of pyrrhotite surface is 20 to 100 times faster than that of pyrite, easily forming hydrophilic layers of Fe(OH)3 and FeO(OH) and FeSO4. FeSO4 further reacts with Ca in water... 2+ The reaction generates a hydrophilic CaSO4 film. The Fe(OH)3, FeO(OH), and CaSO4 hydrophilic films all hinder the contact reaction between xanthate collectors and the surface of pyrrhotite minerals, and also reduce the hydrophobicity of pyrrhotite, thereby reducing its floatability and preventing its removal during the desulfurization stage. Traditional flotation methods also struggle to effectively remove pyrrhotite, resulting in severely excessive sulfur content in the iron concentrate after weak magnetic separation of the flotation tailings.

[0004] In the prior art, patent CN110586336A discloses a low-alkali, pre-magnetic flotation followed by flotation method for beneficiating pyrrhotite. This patent involves copper flotation roughing, copper flotation cleaning, and copper flotation scavenging processes on the pyrrhotite ore. The tailings from the copper flotation scavenging process are then subjected to magnetic separation, followed by sulfur flotation scavenging of the tailings. Finally, the concentrate obtained from the magnetic separation process undergoes a secondary desulfurization process to obtain iron concentrate. Although this patented method combines flotation and magnetic separation, the sulfur content in the resulting iron concentrate is still only 0.58%, which is insufficient to meet the required standards.

[0005] In view of this, it is necessary to design an improved magnetic levitation combined with high-sulfur copper-bearing magnetite beneficiation method to solve the above problems. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite, which can be easily implemented industrially to obtain iron concentrate with a sulfur content of less than 0.3% and an iron grade of more than 65.5%, while simultaneously obtaining qualified copper concentrate and sulfur concentrate products.

[0007] To achieve the above objectives, the present invention provides a magnetic levitation combined method for beneficiating high-sulfur copper-bearing magnetite, comprising the following steps:

[0008] S1. After crushing the high-sulfur copper-bearing magnetite, wet grinding is performed, and water is added to adjust the slurry to obtain the first slurry.

[0009] S2. The first slurry obtained in step S1 is subjected to one copper roughing, one copper scavenging, two copper cleaning, and one fine scavenging to obtain copper concentrate, sulfur concentrate 1 and copper tailings.

[0010] S3. Perform a magnetic separation operation on the copper tailings obtained in step S2 to obtain magnetic concentrate and tailings 1;

[0011] S4. After demagnetizing the magnetic concentrate obtained in step S3, water is added to adjust the slurry to obtain the second slurry.

[0012] S5. The second slurry obtained in step S4 is subjected to two sulfur roughing processes, one sulfur scavenging process, and two sulfur cleaning processes to obtain sulfur concentrate 2 and desulfurized tailings.

[0013] S6. Perform two magnetic separation and cleaning operations on the desulfurized tailings obtained in step S5 to obtain iron concentrate, tailings 2 and tailings 3.

[0014] S7. Combine the sulfur concentrate 1 obtained in step S2 and the sulfur concentrate 2 obtained in step S5 to obtain the final sulfur concentrate; combine the tailings 1 obtained in step S3 and the tailings 2 and tailings 3 obtained in step S6 to obtain the final tailings.

[0015] As a further improvement of the present invention, the copper roughing and copper scavenging processes in step S2, and the sulfur roughing and sulfur scavenging processes in step S5, all use compound frother F-1; the compound frother F-1 is compounded from diethyl phthalate and pine oil in a mass ratio of 2:1 to 5.

[0016] As a further improvement of the present invention, in step S2, the reagents used in the rough copper selection include 10-30 g / t of ethyl thiocyanate and 15-20 g / t of the compound frother F-1; the reagents used in the scavenging copper selection include 5-10 g / t of ethyl thiocyanate and 5-10 g / t of the compound frother F-1; in the fine copper selection, the reagents used in the first copper selection include 200-400 g / t of lime, and the reagents used in the second copper selection include 100-300 g / t of lime; the reagents used in the fine scavenging copper selection include 2-5 g / t of ethyl thiocyanate.

[0017] As a further improvement of the present invention, in step S5, during the sulfur roughing process, the first sulfur roughing uses 1000-3000 g / t of sulfuric acid to adjust the pH of the pulp to 6-6.5. The reagents used in the first sulfur roughing also include 50-200 g / t of copper sulfate, 100-300 g / t of butyl xanthate, 10-30 g / t of butylammonium black, and 5-20 g / t of the compound frother F-1. The reagents used in the second sulfur roughing include 300- The reagents used in the sulfur scavenging process include 100-800 g / t sulfuric acid, 10-50 g / t copper sulfate, 30-100 g / t butyl xanthate, 0-10 g / t butyl ammonium black powder, and 5-15 g / t of the compound frother F-1.

[0018] As a further improvement of the present invention, in step S3, the magnetic field strength of the magnetic separation operation is 3000-3500GS.

[0019] As a further improvement of the present invention, in step S6, during the two magnetic separation and selection operations, the magnetic field strength of the first magnetic separation and selection operation is 1500-2500GS, and the magnetic field strength of the second magnetic separation and selection operation is 1000-1500GS.

[0020] As a further improvement of the present invention, in step S1, the crushing is: crushing high-sulfur copper-bearing magnetite to a particle size of less than 2 mm; the wet grinding is: grinding the ore sample to a particle size of less than 0.074 mm, where 67% to 80% of the particles are smaller.

[0021] As a further improvement of the present invention, in step S1, 100-300 g / t of sodium sulfide is added during the wet grinding process.

[0022] As a further improvement of the present invention, in step S1, the mass concentration of the first slurry is 28% to 32%.

[0023] As a further improvement of the present invention, in step S4, the mass concentration of the second slurry is 20% to 28%.

[0024] The beneficial effects of this invention are:

[0025] 1. The magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite provided by this invention comprehensively recovers resources from high-sulfur copper-bearing magnetite by adopting a magnetic levitation combined method. Based on the differences in floatability and specific magnetic coefficient of magnetite, sulfur-bearing minerals and gangue, the method is designed with four stages of operation: floatability of copper and sulfur, magnetic separation, enhanced desulfurization and magnetic separation. By organically combining these four stages, it is possible to process easily floatable copper-sulfur minerals, gangue, difficult-to-float minerals and magnetic minerals in the raw ore in stages, gradually reducing the sulfur content in the slurry and effectively recovering iron, sulfur and copper elements in the raw ore, thereby obtaining iron concentrate with a sulfur content of less than 0.3% and an iron grade of more than 65.5%, as well as qualified sulfur concentrate and copper concentrate products.

[0026] 2. The magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite provided by this invention employs a process that is easily implemented industrially. It exhibits strong adaptability to high-sulfur copper-bearing magnetite ore types, reduces the pH requirement of the overall slurry, and achieves effective desulfurization in a weakly acidic to neutral environment. This significantly reduces the corrosiveness to beneficiation equipment, offering a clear advantage over traditional iron concentrate desulfurization under low pH conditions. Furthermore, this invention reduces the difficulty of copper-sulfur separation through copper-sulfur floatability processes, resulting in qualified copper concentrate and some sulfur concentrate. Combining this with magnetic separation and enhanced desulfurization flotation effectively improves the grade of the final iron concentrate and effectively removes pyrrhotite from the slurry, further reducing the sulfur content of the iron concentrate.

[0027] 3. This invention, through extensive research, optimizes the composition of reagents for the floatable and enhanced desulfurization stages of copper and sulfur, thereby improving flotation efficiency. Specifically, the compound frother F-1 used in this invention is composed of diethyl phthalate and pine oil in a specific ratio. The proportion of this compound frother increases with the increase of pyrrhotite content in the raw ore. Replacing traditional frothers with the compound frother F-1 of this invention results in a more stable and durable mineralized froth layer during flotation, with less impact on the flotation of slime. This is of practical significance for improving the recovery rate of sulfide ores with poor floatability and slow flotation rates, such as pyrrhotite. Attached Figure Description

[0028] Figure 1 A schematic diagram of the process flow for the magnetic levitation combined high-sulfur copper-bearing magnetite beneficiation method provided by the present invention. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] This invention provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite, the process flow diagram of which is shown below. Figure 1 As shown, it includes the following steps:

[0033] S1. After crushing the high-sulfur copper-bearing magnetite, wet grinding is performed, and water is added to adjust the slurry to obtain the first slurry.

[0034] S2. The first slurry obtained in step S1 is subjected to copper and sulfur flotation treatment, specifically including one copper roughing, one copper scavenging, two copper cleaning, and one fine scavenging treatment to obtain copper concentrate, sulfur concentrate 1 and copper tailings.

[0035] S3. Perform a magnetic separation operation on the copper tailings obtained in step S2 to obtain magnetic concentrate and tailings 1;

[0036] S4. After demagnetizing the magnetic concentrate obtained in step S3, water is added to adjust the slurry to obtain the second slurry.

[0037] S5. The second slurry obtained in step S4 is subjected to enhanced desulfurization treatment, specifically including two sulfur roughing treatments, one sulfur scavenging treatment, and two sulfur cleaning treatments to obtain sulfur concentrate 2 and desulfurized tailings.

[0038] S6. Perform two magnetic separation and cleaning operations on the desulfurized tailings obtained in step S5 to obtain iron concentrate, tailings 2 and tailings 3.

[0039] S7. Combine the sulfur concentrate 1 obtained in step S2 and the sulfur concentrate 2 obtained in step S5 to obtain the final sulfur concentrate; combine the tailings 1 obtained in step S3 and the tailings 2 and tailings 3 obtained in step S6 to obtain the final tailings.

[0040] In step S1, the crushing is: crushing high-sulfur copper-bearing magnetite to a particle size of less than 2 mm; the wet grinding is: grinding the ore sample to a particle size of less than 0.074 mm, with 67% to 80% of the particles being smaller; 100 to 300 g / t of sodium sulfide is also added during the wet grinding process; the mass concentration of the first slurry is 28% to 32%.

[0041] In step S2, during the copper roughing process, the reagents used include 10-30 g / t of ethyl thiocyanate and 15-20 g / t of compound frother F-1. The resulting copper roughing tailings enter the copper scavenging operation, and the copper roughing concentrate enters the first copper cleaning operation. During the copper scavenging process, the reagents used include 5-10 g / t of ethyl thiocyanate and 5-10 g / t of compound frother F-1. The resulting copper scavenging tailings are the copper tailings, which enter the subsequent magnetic separation operation, while the copper scavenging concentrate is returned to the previous copper roughing operation. During the copper cleaning process, the reagents used in the first copper cleaning process include 200-400 g / t of lime. The resulting first copper cleaning concentrate enters the second copper cleaning operation, and the first copper cleaning tailings enter the copper cleaning scavenging operation. The reagents used in the second copper cleaning process include 100-300 g / t of lime, and the reagents used in the cleaning scavenging process include 2-5 g / t of ethyl thiocyanate. The concentrate from the second copper refining process is collected as copper concentrate, while the concentrate from the copper scavenging process is collected as sulfur concentrate 1, which is then combined with sulfur concentrate 2 obtained from subsequent processes to form sulfur concentrate. The tailings from the second copper refining process and the copper scavenging process are combined and returned to the first copper refining process.

[0042] In step S3, the magnetic field strength of the magnetic separation operation is 3000-3500GS.

[0043] In step S4, the mass concentration of the second slurry is 20% to 28%.

[0044] In step S5, during the sulfur roughing process, the first sulfur roughing uses 1000–3000 g / t of sulfuric acid to adjust the pulp pH to 6–6.5. The reagents used in the first sulfur roughing also include 50–200 g / t of copper sulfate, 100–300 g / t of butyl xanthate, 10–30 g / t of butylammonium black, and 5–20 g / t of compound frother F-1. The tailings from the first sulfur roughing enter the second sulfur roughing operation. The reagents used in the second sulfur roughing include 300–1000 g / t of sulfuric acid, 20–90 g / t of copper sulfate, 30–100 g / t of butyl xanthate, 2–10 g / t of butylammonium black, and 5–15 g / t of compound frother F-1. The concentrates from the second and first sulfur roughing processes are combined and then enter the first sulfur cleaning operation. The tailings from the second sulfur roughing process enter the sulfur scavenging operation. During the sulfur scavenging process, the reagents used include 100–800 g / t of sulfuric acid, 10–50 g / t of copper sulfate, 30–100 g / t of butyl xanthate, 0–10 g / t of butylammonium black, and 5–15 g / t of compound frother F-1. The tailings from the sulfur scavenging process are used as desulfurization tailings and enter the subsequent magnetic separation and cleaning operation. No reagents are added in the first and second sulfur cleaning processes. The concentrate from the first sulfur cleaning process enters the second sulfur cleaning process, while the tailings from the first sulfur cleaning process are combined with the concentrate from the sulfur scavenging process and returned to the first sulfur roughing process. The tailings from the second sulfur cleaning process are returned to the first sulfur cleaning process, and the concentrate from the second sulfur cleaning process is sulfur concentrate 2, which is combined with sulfur concentrate 1 and collected as the final sulfur concentrate.

[0045] In the copper roughing and scavenging processes in step S2, and in the sulfur roughing and scavenging processes in step S5, a compound frother F-1 was used. The compound frother F-1 was prepared by mixing diethyl phthalate and pine oil in a mass ratio of 2:1 to 5. Furthermore, the higher the pyrrhotite content in the raw ore, the higher the proportion of diethyl phthalate. When the pyrrhotite content in the raw ore was 0.5%... When the content of pyrrhotite in the raw ore is 1%, the mass ratio of diethyl phthalate to pine oil in the compound foaming agent F-1 is 2:4-5; when the content of pyrrhotite in the raw ore is 1-1.5%, the mass ratio of diethyl phthalate to pine oil in the compound foaming agent F-1 is 2:3-4; when the content of pyrrhotite in the raw ore is more than 1.5%, the mass ratio of diethyl phthalate to pine oil in the compound foaming agent F-1 is 2:1-3.

[0046] In step S6, during the two magnetic separation and refining operations, the magnetic field strength of the first magnetic separation and refining operation is 1500-2500 GS, and the magnetic field strength of the second magnetic separation and refining operation is 1000-1500 GS.

[0047] The following detailed description of the magnetic levitation combined high-sulfur copper-bearing magnetite beneficiation method provided by the present invention is based on specific embodiments.

[0048] Example 1

[0049] This embodiment provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. The high-sulfur copper-bearing magnetite targeted in this embodiment has the following elemental contents: TFe 46.34%, S 1.61%, Cu 0.07%, SiO2 11.88%, MgO 6.58%, Al2O3 4.12%, P 0.081%. The proportion of magnetic iron to total iron in this high-sulfur copper-bearing magnetite ore is 90.09%, with S mainly occurring in pyrrhotite and pyrite, and a small portion occurring in sulfide minerals such as chalcopyrite.

[0050] In this embodiment, the ore contains 41.74% magnetic iron and 1.76% pyrrhotite. Based on this, a compound foaming agent F-1 is prepared by mixing diethyl phthalate and pine oil stock solution at a mass ratio of 2:1. The specific mineral processing steps are as follows:

[0051] S1. Crush the high-sulfur copper-bearing magnetite to -2mm, and then perform wet grinding on the crushed ore sample. Add 300g / t of sodium sulfide to the ball mill and grind until -0.074mm accounts for 70%. Add water to adjust the slurry concentration to 32% to obtain the first slurry.

[0052] S2. The first slurry obtained in step S1 is subjected to copper and sulfur flotation treatment, specifically including one copper roughing, one copper scavenging, two copper cleaning, and one fine scavenging treatment to obtain copper concentrate, sulfur concentrate 1 and copper tailings.

[0053] The copper roughing process uses reagents including 25 g / t of ethyl thiocyanate collector and 15 g / t of compound frother F-1. The resulting copper roughing tailings are then fed into the copper scavenging process, and the copper roughing concentrate is fed into the first copper cleaning process. During the copper scavenging process, reagents include 10 g / t of ethyl thiocyanate collector and 10 g / t of compound frother F-1. The resulting copper scavenging tailings, known as copper tailings, are fed into the subsequent magnetic separation process, while the copper scavenging concentrate is returned to the previous copper roughing process. In the copper cleaning process, the first copper cleaning process uses reagents including 300 g / t of lime. The resulting first copper cleaning concentrate is fed into the second copper cleaning process, and the first copper cleaning tailings are fed into the copper cleaning scavenging process. The second copper cleaning process uses reagents including 200 g / t of lime, and the cleaning scavenging process uses reagents including 3 g / t of ethyl thiocyanate collector. The concentrate from the second copper refining process is collected as copper concentrate, while the concentrate from the copper scavenging process is collected as sulfur concentrate 1, which is then combined with sulfur concentrate 2 obtained from subsequent processes to form sulfur concentrate. The tailings from the second copper refining process and the copper scavenging process are combined and returned to the first copper refining process.

[0054] S3. Perform a magnetic separation operation on the copper tailings obtained in step S2, with a magnetic field strength of 3500GS, to obtain magnetic concentrate and tailings 1.

[0055] S4. After demagnetizing the magnetic concentrate obtained in step S3, water is added to adjust the slurry to obtain a second slurry with a mass concentration of 25%.

[0056] S5. The second slurry obtained in step S4 is subjected to enhanced desulfurization treatment, specifically including two sulfur roughing treatments, one sulfur scavenging treatment, and two sulfur cleaning treatments to obtain sulfur concentrate 2 and desulfurized tailings.

[0057] In the sulfur roughing process, the reagents used in the first sulfur roughing stage include 2000 g / t of sulfuric acid as a surface cleaning agent (the pH of the slurry becomes 6.5 after adding sulfuric acid), 100 g / t of copper sulfate as an activator, 150 g / t of butyl xanthate as a collector, 20 g / t of butylammonium black powder, and 10 g / t of compound frother F-1. The tailings from the first sulfur roughing stage enter the second sulfur roughing stage. The reagents used in the second sulfur roughing stage include 1000 g / t of sulfuric acid as a surface cleaning agent, 50 g / t of copper sulfate as an activator, 50 g / t of butyl xanthate, 5 g / t of butylammonium black powder, and 10 g / t of compound frother F-1. The concentrates from the second and first sulfur roughing stages are combined and then enter the first sulfur cleaning stage. The tailings from the second sulfur roughing stage enter the sulfur scavenging stage. During the sulfur scavenging process, the reagents used include 500 g / t of sulfuric acid as a surface cleaning agent, 25 g / t of copper sulfate as an activator, 25 g / t of butyl xanthate, 5 g / t of butylammonium black, and 5 g / t of compound frother F-1. The tailings from the sulfur scavenging process are used as desulfurization tailings and enter the subsequent magnetic separation and cleaning operation. No reagents are added in the first and second sulfur cleaning processes. The concentrate from the first sulfur cleaning process enters the second sulfur cleaning process, while the tailings from the first sulfur cleaning process are combined with the concentrate from the sulfur scavenging process and returned to the first sulfur roughing process. The tailings from the second sulfur cleaning process are returned to the first sulfur cleaning process, and the concentrate from the second sulfur cleaning process is sulfur concentrate 2, which is combined with sulfur concentrate 1 and collected as the final sulfur concentrate.

[0058] S6. Perform two magnetic separation and refining operations on the desulfurized tailings obtained in step S5.

[0059] In the first magnetic separation, the magnetic field strength is 2500GS. The concentrate obtained is then processed into the second magnetic separation, and the resulting tailings are denoted as tailings 2. In the second magnetic separation, the magnetic field strength is 1500GS. The concentrate obtained is iron concentrate, and the resulting tailings are denoted as tailings 3.

[0060] S7. Combine the sulfur concentrate 1 obtained in step S2 and the sulfur concentrate 2 obtained in step S5 to obtain the final sulfur concentrate; combine the tailings 1 obtained in step S3 and the tailings 2 and tailings 3 obtained in step S6 to obtain the final tailings.

[0061] Through the above methods, this embodiment ultimately obtained an iron concentrate with an iron grade of 66.18%, an iron recovery rate of 94.46%, and a sulfur content of 0.23%; a sulfur concentrate with a sulfur grade of 35.61% and a recovery rate of 66.48%; and a copper concentrate with a copper grade of 19.68% and a recovery rate of 53.86%.

[0062] Comparative Example 1

[0063] This comparative example provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. Compared with Example 1, the only difference is that steps S4 and S5 are omitted, and the magnetic concentrate obtained in step S3 is subjected to two magnetic separations in step S6 to obtain the final iron concentrate. The tailings from the three magnetic separation stages are combined into the final tailings. The ore and related parameters of the remaining steps in this comparative example are the same as those in Example 1, and will not be repeated here.

[0064] This comparative example ultimately yielded an iron concentrate with an iron grade of 65.84%, an iron recovery rate of 95.02%, and a sulfur content of 1.20%; a sulfur concentrate with a sulfur grade of 40.83% and a recovery rate of 23.30%; and a copper concentrate with a copper grade of 19.72% and a recovery rate of 53.78%. Compared to Example 1, the sulfur content in the iron concentrate product of this comparative example was significantly higher than the national standard (S≤0.4% in iron concentrate), the sulfur recovery rate in the sulfur concentrate was significantly reduced, and the copper index did not change much. This demonstrates that the enhanced desulfurization operation in this invention is of great significance for reducing the sulfur content of the final iron concentrate.

[0065] Comparative Example 2

[0066] This comparative example provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. The only difference from Example 1 is that the demagnetization treatment in step S4 is omitted. The ore and other relevant parameters in this comparative example are the same as those in Example 1, and will not be repeated here.

[0067] This comparative example ultimately yielded an iron concentrate with an iron grade of 66.01%, an iron recovery rate of 93.66%, and a sulfur content of 0.23%; a sulfur concentrate with a sulfur grade of 34.23% and a recovery rate of 66.94%; and a copper concentrate with a copper grade of 19.56% and a recovery rate of 53.38%. Compared with Example 1, the sulfur content of the iron concentrate product in this comparative example did not exceed the standard, but the amount of magnetic iron minerals mixed in the sulfur concentrate increased, resulting in a certain degree of reduction in the iron concentrate recovery rate. The copper index did not change significantly, indicating that adding demagnetization operations in the enhanced desulfurization stage has a positive effect on improving the iron recovery rate.

[0068] Comparative Example 3

[0069] This comparative example provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. Compared with Example 1, the only difference is that the compound frother F-1 used in steps S2 and S5 is replaced with a single pine oil. The ore and other relevant parameters in this comparative example are the same as those in Example 1, and will not be repeated here.

[0070] This comparative example ultimately yielded an iron concentrate with an iron grade of 65.78%, an iron recovery rate of 94.32%, and a sulfur content of 0.35%; a sulfur concentrate with a sulfur grade of 35.25% and a recovery rate of 62.76%; and a copper concentrate with a copper grade of 19.89% and a recovery rate of 49.49%. Compared with Example 1, it can be seen that the compound frother F-1 developed in this invention has a more significant effect on the desulfurization of iron concentrate and the improvement of copper recovery in the entire beneficiation system.

[0071] Comparative Example 4

[0072] This comparative example provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. Compared with Example 1, the only difference is that the mass ratio of diethyl phthalate and pine oil in the compound frother F-1 used in steps S2 and S5 is changed to 1:2. The ore and other relevant parameters in this comparative example are the same as those in Example 1, and will not be repeated here.

[0073] This comparative example ultimately yielded an iron concentrate with an iron grade of 65.89%, an iron recovery rate of 94.12%, and a sulfur content of 0.43%; a sulfur concentrate with a sulfur grade of 34.12% and a recovery rate of 53.94%; and a copper concentrate with a copper grade of 19.65% and a recovery rate of 51.76%. Compared with Example 1, it can be seen that the ratio of diethyl phthalate and pine oil in the compound frother F-1 developed in this invention has a certain impact on the desulfurization effect and copper recovery of the iron concentrate in the entire beneficiation system. Furthermore, this ratio is closely related to the proportion of pyrrhotite in the raw ore, and the ratio of the frother needs to be adjusted according to the proportion of pyrrhotite.

[0074] Comparative Example 5

[0075] This comparative example provides a comparison of the desulfurization effect of a conventional low-pH process on high-sulfur magnetite using a traditional "flotation-magnetic separation desulfurization process." The difference between this comparative example and Example 1 lies in the process flow: one copper-sulfur mixed flotation roughing, four scavenging stages, one mixed flotation cleaning, one copper-sulfur separation roughing, two copper-sulfur separation cleaning, and two copper-sulfur separation scavenging. The flotation tailings undergo three-stage magnetic separation to obtain copper concentrate, sulfur concentrate, iron concentrate, and tailings. The specific reagent formulation is conventional and will not be detailed here. The pulp pH for the copper-sulfur roughing is 4.

[0076] This comparative example ultimately yielded an iron concentrate with an iron grade of 65.01%, an iron recovery rate of 94.02%, and a sulfur content of 0.42%; a sulfur concentrate with a sulfur grade of 38.55% and a recovery rate of 55.95%; and a copper concentrate with a copper grade of 18.95% and a recovery rate of 53.25%. Compared to Example 1, the pH of the slurry for copper-sulfur roughing in this comparative example was 4, which placed higher demands on the corrosion resistance of the equipment. However, the sulfur content in the iron concentrate product still exceeded the standard, the copper recovery rate and grade in the copper concentrate product decreased slightly, and the sulfur grade in the sulfur concentrate increased slightly, but the recovery rate decreased significantly. This further demonstrates the significant advantages of the magnetic levitation combined high-sulfur copper-bearing magnetite beneficiation method proposed in this invention.

[0077] Example 2

[0078] This embodiment provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. The high-sulfur copper-bearing magnetite targeted in this embodiment has the following elemental contents: TFe 45.53%, S 1.52%, Cu 0.08%, SiO2 12.94%, MgO 8.14%, Al2O3 5.38%, and P 0.023%. The proportion of magnetic iron to total iron in this high-sulfur copper-bearing magnetite ore is 89.32%, with S mainly occurring in pyrrhotite and pyrite, and a small portion occurring in sulfide minerals such as chalcopyrite.

[0079] In this embodiment, the ore contains 40.67% magnetic iron and 1.89% pyrrhotite. Based on this, a compound foaming agent F-1 is prepared by mixing diethyl phthalate and pine oil stock solution at a mass ratio of 1:1. The specific mineral processing steps are as follows:

[0080] S1. Crush the high-sulfur copper-bearing magnetite to -2mm, and then perform wet grinding on the crushed ore sample. Add 300g / t of sodium sulfide to the ball mill and grind until -0.074mm accounts for 67%. Add water to adjust the slurry concentration to 30% to obtain the first slurry.

[0081] S2. The first slurry obtained in step S1 is subjected to copper and sulfur flotation treatment, specifically including one copper roughing, one copper scavenging, two copper cleaning, and one fine scavenging treatment to obtain copper concentrate, sulfur concentrate 1 and copper tailings.

[0082] The copper roughing process uses reagents including 30 g / t of ethyl thiocyanate collector and 15 g / t of compound frother F-1. The resulting copper roughing tailings are then fed into the copper scavenging process, and the copper roughing concentrate is fed into the first copper cleaning process. During the copper scavenging process, reagents include 15 g / t of ethyl thiocyanate collector and 10 g / t of compound frother F-1. The resulting copper scavenging tailings, known as copper tailings, are fed into the subsequent magnetic separation process, while the copper scavenging concentrate is returned to the previous copper roughing process. In the copper cleaning process, the first copper cleaning process uses reagents including 300 g / t of lime. The resulting first copper cleaning concentrate is fed into the second copper cleaning process, and the first copper cleaning tailings are fed into the copper cleaning scavenging process. The second copper cleaning process uses reagents including 200 g / t of lime, and the cleaning scavenging process uses reagents including 3 g / t of ethyl thiocyanate collector. The concentrate from the second copper refining process is collected as copper concentrate, while the concentrate from the copper scavenging process is collected as sulfur concentrate 1, which is then combined with sulfur concentrate 2 obtained from subsequent processes to form sulfur concentrate. The tailings from the second copper refining process and the copper scavenging process are combined and returned to the first copper refining process.

[0083] S3. Perform a magnetic separation operation on the copper tailings obtained in step S2, with a magnetic field strength of 3200GS, to obtain magnetic concentrate and tailings 1.

[0084] S4. After demagnetizing the magnetic concentrate obtained in step S3, water is added to adjust the slurry to obtain a second slurry with a mass concentration of 23%.

[0085] S5. The second slurry obtained in step S4 is subjected to enhanced desulfurization treatment, specifically including two sulfur roughing treatments, one sulfur scavenging treatment, and two sulfur cleaning treatments to obtain sulfur concentrate 2 and desulfurized tailings.

[0086] In the sulfur roughing process, the reagents used in the first sulfur roughing stage include 1500 g / t of sulfuric acid as a surface cleaning agent (the pH of the slurry becomes 6.1 after adding sulfuric acid), 100 g / t of copper sulfate as an activator, 130 g / t of butyl xanthate as a collector, 15 g / t of butylammonium black powder, and 10 g / t of compound frother F-1. The tailings from the first sulfur roughing stage enter the second sulfur roughing stage. The reagents used in the second sulfur roughing stage include 800 g / t of sulfuric acid as a surface cleaning agent, 50 g / t of copper sulfate as an activator, 50 g / t of butyl xanthate, 5 g / t of butylammonium black powder, and 10 g / t of compound frother F-1. The concentrates from the second and first sulfur roughing stages are combined and then enter the first sulfur cleaning stage. The tailings from the second sulfur roughing stage enter the sulfur scavenging stage. During the sulfur scavenging process, the reagents used include 500 g / t of sulfuric acid as a surface cleaning agent, 25 g / t of copper sulfate as an activator, 20 g / t of butyl xanthate, 5 g / t of butylammonium black, and 5 g / t of compound frother F-1. The tailings from the sulfur scavenging process are used as desulfurization tailings and enter the subsequent magnetic separation and cleaning operation. No reagents are added in the first and second sulfur cleaning processes. The concentrate from the first sulfur cleaning process enters the second sulfur cleaning process, while the tailings from the first sulfur cleaning process are combined with the concentrate from the sulfur scavenging process and returned to the first sulfur roughing process. The tailings from the second sulfur cleaning process are returned to the first sulfur cleaning process, and the concentrate from the second sulfur cleaning process is sulfur concentrate 2, which is combined with sulfur concentrate 1 and collected as the final sulfur concentrate.

[0087] S6. Perform two magnetic separation and refining operations on the desulfurized tailings obtained in step S5.

[0088] In the first magnetic separation, the magnetic field strength is 2500GS. The concentrate obtained is then processed into the second magnetic separation, and the resulting tailings are denoted as tailings 2. In the second magnetic separation, the magnetic field strength is 1500GS. The concentrate obtained is iron concentrate, and the resulting tailings are denoted as tailings 3.

[0089] S7. Combine the sulfur concentrate 1 obtained in step S2 and the sulfur concentrate 2 obtained in step S5 to obtain the final sulfur concentrate; combine the tailings 1 obtained in step S3 and the tailings 2 and tailings 3 obtained in step S6 to obtain the final tailings.

[0090] Through the above methods, this embodiment ultimately obtained an iron concentrate with an iron grade of 65.69%, an iron recovery rate of 94.19%, and a sulfur content of 0.21%; a sulfur concentrate with a sulfur grade of 33.75% and a recovery rate of 65.17%; and a copper concentrate with a copper grade of 21.89% and a recovery rate of 55.08%.

[0091] Example 3

[0092] This embodiment provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite. The high-sulfur copper-bearing magnetite targeted in this embodiment has the following elemental contents: TFe 47.16%, S 2.35%, Cu 0.25%, SiO2 11.87%, MgO 7.99%, Al2O3 6.38%, and P 0.011%. The proportion of magnetic iron to total iron in this high-sulfur copper-bearing magnetite ore is 87.18%, and sulfur is mainly hosted in sulfide minerals such as pyrite, pyrrhotite, and chalcopyrite.

[0093] In this embodiment, the ore contains 41.11% magnetic iron and 1.24% pyrrhotite. Based on this, a compound foaming agent F-1 is prepared by mixing diethyl phthalate and pine oil stock solution at a mass ratio of 2:3. The specific mineral processing steps are as follows:

[0094] S1. Crush the high-sulfur copper-bearing magnetite to -2mm, and then perform wet grinding on the crushed ore sample. Add 200g / t of sodium sulfide to the ball mill and grind until -0.074mm accounts for 80%. Add water to adjust the slurry concentration to 29% to obtain the first slurry.

[0095] S2. The first slurry obtained in step S1 is subjected to copper and sulfur flotation treatment, specifically including one copper roughing, one copper scavenging, two copper cleaning, and one fine scavenging treatment to obtain copper concentrate, sulfur concentrate 1 and copper tailings.

[0096] The copper roughing process uses reagents including 40 g / t of ethyl thiocyanate collector and 15 g / t of compound frother F-1. The resulting copper roughing tailings are then fed into the copper scavenging process, and the copper roughing concentrate is fed into the first copper cleaning process. During the copper scavenging process, reagents include 20 g / t of ethyl thiocyanate collector and 10 g / t of compound frother F-1. The resulting copper scavenging tailings, known as copper tailings, are fed into the subsequent magnetic separation process, while the copper scavenging concentrate is returned to the previous copper roughing process. In the copper cleaning process, the first copper cleaning process uses reagents including 400 g / t of lime. The resulting first copper cleaning concentrate is fed into the second copper cleaning process, and the first copper cleaning tailings are fed into the copper cleaning scavenging process. The second copper cleaning process uses reagents including 200 g / t of lime, and the cleaning scavenging process uses reagents including 3 g / t of ethyl thiocyanate collector. The concentrate from the second copper refining process is collected as copper concentrate, while the concentrate from the copper scavenging process is collected as sulfur concentrate 1, which is then combined with sulfur concentrate 2 obtained from subsequent processes to form sulfur concentrate. The tailings from the second copper refining process and the copper scavenging process are combined and returned to the first copper refining process.

[0097] S3. Perform a magnetic separation operation on the copper tailings obtained in step S2, with a magnetic field strength of 3500GS, to obtain magnetic concentrate and tailings 1.

[0098] S4. After demagnetizing the magnetic concentrate obtained in step S3, water is added to adjust the slurry to obtain a second slurry with a mass concentration of 24%.

[0099] S5. The second slurry obtained in step S4 is subjected to enhanced desulfurization treatment, specifically including two sulfur roughing treatments, one sulfur scavenging treatment, and two sulfur cleaning treatments to obtain sulfur concentrate 2 and desulfurized tailings.

[0100] In the sulfur roughing process, the reagents used in the first sulfur roughing stage include 2000 g / t of sulfuric acid as a surface cleaning agent (the pH of the slurry becomes 6.0 after adding sulfuric acid), 100 g / t of copper sulfate as an activator, 150 g / t of butyl xanthate as a collector, 15 g / t of butylammonium black powder, and 10 g / t of compound frother F-1. The tailings from the first sulfur roughing stage enter the second sulfur roughing stage. The reagents used in the second sulfur roughing stage include 800 g / t of sulfuric acid as a surface cleaning agent, 40 g / t of copper sulfate as an activator, 50 g / t of butyl xanthate, 5 g / t of butylammonium black powder, and 10 g / t of compound frother F-1. The concentrates from the second and first sulfur roughing stages are combined and then enter the first sulfur cleaning stage. The tailings from the second sulfur roughing stage enter the sulfur scavenging stage. During the sulfur scavenging process, the reagents used include 500 g / t of sulfuric acid as a surface cleaning agent, 25 g / t of copper sulfate as an activator, 20 g / t of butyl xanthate, 5 g / t of butylammonium black, and 5 g / t of compound frother F-1. The tailings from the sulfur scavenging process are used as desulfurization tailings and enter the subsequent magnetic separation and cleaning operation. No reagents are added in the first and second sulfur cleaning processes. The concentrate from the first sulfur cleaning process enters the second sulfur cleaning process, while the tailings from the first sulfur cleaning process are combined with the concentrate from the sulfur scavenging process and returned to the first sulfur roughing process. The tailings from the second sulfur cleaning process are returned to the first sulfur cleaning process, and the concentrate from the second sulfur cleaning process is sulfur concentrate 2, which is combined with sulfur concentrate 1 and collected as the final sulfur concentrate.

[0101] S6. Perform two magnetic separation and refining operations on the desulfurized tailings obtained in step S5.

[0102] In the first magnetic separation, the magnetic field strength is 2500GS. The concentrate obtained is then sent to the second magnetic separation operation, and the resulting tailings are denoted as tailings 2. In the second magnetic separation, the magnetic field strength is 1200GS. The concentrate obtained is iron concentrate, and the resulting tailings are denoted as tailings 3.

[0103] S7. Combine the sulfur concentrate 1 obtained in step S2 and the sulfur concentrate 2 obtained in step S5 to obtain the final sulfur concentrate; combine the tailings 1 obtained in step S3 and the tailings 2 and tailings 3 obtained in step S6 to obtain the final tailings.

[0104] Through the above methods, this embodiment ultimately obtained an iron concentrate with an iron grade of 66.58%, an iron recovery rate of 93.67%, and a sulfur content of 0.26%; a sulfur concentrate with a sulfur grade of 30.61% and a recovery rate of 65.40%; and a copper concentrate with a copper grade of 20.11% and a recovery rate of 79.36%.

[0105] A comparison of the various embodiments shows that as the copper and sulfur content in the raw ore increases, the sulfur content in the final iron concentrate increases slightly, and the recovery rate of copper concentrate increases significantly, further demonstrating the strong adaptability of the process.

[0106] In summary, this invention provides a magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite, comprising crushing the high-sulfur copper-bearing magnetite and then wet grinding it, adding water to form a first slurry; then subjecting the first slurry to copper and sulfur flotation treatment to obtain copper concentrate, sulfur concentrate, and copper tailings; then subjecting the copper tailings to magnetic separation to obtain magnetic concentrate and tailings; then subjecting the magnetic concentrate to demagnetization treatment, adding water to form a second slurry, then subjecting the second slurry to enhanced desulfurization treatment to obtain sulfur concentrate and desulfurized tailings; finally, subjecting the desulfurized tailings to two magnetic separation cleaning operations to obtain iron concentrate and tailings. Through the above method, the present invention can utilize the organic combination of four stages: floatable copper and sulfur minerals, magnetic separation, enhanced desulfurization, and magnetic separation to process easily floatable copper and sulfur minerals, gangue, difficult-to-float minerals, and magnetic minerals in the raw ore in stages. This can gradually reduce the sulfur content in the slurry and effectively recover iron, sulfur, and copper elements from the raw ore, thereby obtaining iron concentrate with a sulfur content of less than 0.3% and an iron grade of more than 65.5%, as well as qualified sulfur concentrate and copper concentrate products.

[0107] 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 magnetic levitation combined beneficiation method for high-sulfur copper-bearing magnetite, characterized in that, The steps include the following: S1. After crushing the high-sulfur copper-bearing magnetite, wet grinding is performed, and water is added to adjust the slurry to obtain the first slurry. S2. The first slurry obtained in step S1 is subjected to one copper roughing, one copper scavenging, two copper cleaning, and one fine scavenging to obtain copper concentrate, sulfur concentrate 1 and copper tailings. S3. Perform a magnetic separation operation on the copper tailings obtained in step S2 to obtain magnetic concentrate and tailings 1; S4. After demagnetizing the magnetic concentrate obtained in step S3, water is added to adjust the slurry to obtain the second slurry. S5. The second slurry obtained in step S4 is subjected to two sulfur roughing processes, one sulfur scavenging process, and two sulfur cleaning processes to obtain sulfur concentrate 2 and desulfurized tailings. S6. Perform two magnetic separation and cleaning operations on the desulfurized tailings obtained in step S5 to obtain iron concentrate, tailings 2 and tailings 3. S7. Combine the sulfur concentrate 1 obtained in step S2 and the sulfur concentrate 2 obtained in step S5 to obtain the final sulfur concentrate; combine the tailings 1 obtained in step S3 and the tailings 2 and tailings 3 obtained in step S6 to obtain the final tailings. In step S2, the copper roughing and scavenging processes, and in step S5, the sulfur roughing and scavenging processes, all utilize compound frother F-1. Compound frother F-1 is composed of diethyl phthalate and pine oil in a mass ratio of 2:1 to 5. When the content of pyrrhotite in the raw ore is 0.5% to 1%, the mass ratio of diethyl phthalate to pine oil in compound frother F-1 is 2:4 to 5. When the content of pyrrhotite in the raw ore is 1% to 1.5%, the mass ratio of diethyl phthalate to pine oil in compound frother F-1 is 2:3 to 4. When the content of pyrrhotite in the raw ore exceeds 1.5%, the mass ratio of diethyl phthalate to pine oil in compound frother F-1 is 2:1 to 3. In step S5, during the sulfur roughing process, the first sulfur roughing uses 1000-3000 g / t of sulfuric acid to adjust the pulp pH to 6-6.

5. The reagents used in the first sulfur roughing also include 50-200 g / t of copper sulfate, 100-300 g / t of butyl xanthate, 10-30 g / t of butylammonium black, and 5-20 g / t of the compound frother F-1. The reagents used in the second sulfur roughing include 300-1000 g / t of... The reagents used in the sulfur scavenging process include 100-800 g / t of sulfuric acid, 10-50 g / t of copper sulfate, 30-100 g / t of butyl xanthate, 0-10 g / t of butyl ammonium black powder, and 5-15 g / t of the compound frother F-1.

2. The maglev-integrated high-sulfur copper-bearing magnetite beneficiation method according to claim 1, characterized in that: In step S2, during the roughing of copper, the reagents used include 10-30 g / t of ethyl thiocyanate and 15-20 g / t of the compound frother F-1; during the scavenging of copper, the reagents used include 5-10 g / t of ethyl thiocyanate and 5-10 g / t of the compound frother F-1; during the cleaning of copper, the reagents used for the first copper cleaning include 200-400 g / t of lime, and the reagents used for the second copper cleaning include 100-300 g / t of lime; during the fine scavenging, the reagents used include 2-5 g / t of ethyl thiocyanate.

3. The method for beneficiating high-sulfur copper-bearing magnetite using magnetic levitation as described in claim 1, characterized in that: In step S3, the magnetic field strength of the magnetic separation operation is 3000~3500GS.

4. The magnetic levitation combined with high-sulfur copper-bearing magnetite beneficiation method according to claim 1, characterized in that: In step S6, during the two magnetic separation and refining operations, the magnetic field strength of the first magnetic separation and refining operation is 1500~2500GS, and the magnetic field strength of the second magnetic separation and refining operation is 1000~1500GS.

5. The method for beneficiating high-sulfur copper-bearing magnetite using magnetic levitation as described in claim 1, characterized in that: In step S1, the crushing is: crushing high-sulfur copper-bearing magnetite to a particle size of less than 2 mm; the wet grinding is: grinding the ore sample to a particle size of less than 0.074 mm, where 67% to 80% of the particles are smaller.

6. The maglev-integrated beneficiation method for high-sulfur copper-bearing magnetite according to claim 1, characterized in that: In step S1, 100-300 g / t of sodium sulfide is added during the wet grinding process.

7. The maglev-integrated beneficiation method for high-sulfur copper-bearing magnetite according to claim 1, characterized in that: In step S1, the mass concentration of the first slurry is 28%~32%.

8. The method for beneficiating high-sulfur copper-bearing magnetite using magnetic levitation as described in claim 1, characterized in that: In step S4, the mass concentration of the second slurry is 20%~28%.

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