A beneficiation method of high-sulfur low-intensity magnetic separation tailings

Abstract

The application discloses a beneficiation method of high-sulfur weak magnetic separation tailings, and belongs to the technical field of mineral processing. The method comprises the following steps: S100, coarse separation of the high-sulfur weak magnetic separation tailings; S200, coarse weak magnetic separation and coarse strong magnetic separation of the coarse-separated tailings to obtain a first-stage coarse concentrate; S300, regrinding and weak magnetic separation of the first-stage coarse concentrate to obtain a magnetic concentrate and a weak magnetic separation tailing; S400, strong magnetic separation of the weak magnetic separation tailing to obtain a strong magnetic separation concentrate and a strong magnetic separation tailing; S500, desulfurization of the strong magnetic separation concentrate by reverse flotation to obtain a sulfur coarse concentrate and a desulfurization tailing, and then one-time concentration of the sulfur coarse concentrate to obtain a sulfur concentrate; and S600, direct flotation of the desulfurization tailing to obtain a hematite concentrate and a flotation tailing. The application can realize diversified utilization of the tailings, avoids waste of resources, greatly improves the comprehensive utilization degree of resources, and greatly reduces the beneficiation cost.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, and more specifically, relates to a mineral processing method for high-sulfur weak magnetic separation tailings. Background Technology

[0002] Tailings are a typical type of mine solid waste. Although they contain certain useful components, if they are not comprehensively utilized, they will be discharged into tailings ponds, which will not only occupy a large amount of land, but also pose huge safety risks and cause great damage to the surrounding ecological environment. Therefore, the resource utilization of tailings has become a hot research topic.

[0003] The Luohe-type associated copper and sulfur ore deposits, along with complex and difficult-to-process high-sulfur iron ore, are found in the Lujiang-Zongyang volcanic basin. These ores exhibit diverse natural types and complex mineral compositions. The primary useful mineral is magnetite, followed by pseudomorphous hematite, pyrite, and chalcopyrite, with other minerals present in small or trace amounts. Gangue minerals mainly consist of anhydrite, pyroxene, carbonate minerals, apatite, chlorite, and feldspar. These mines primarily recover easily processed magnetite and pyrite, while difficult-to-process hematite is not recovered and is lost to tailings. Furthermore, during the beneficiation process, the recovery of useful minerals such as magnetite and pyrite is insufficient, with small amounts lost to tailings, resulting in resource waste.

[0004] In response to this situation, the applicant previously applied for patent number CN202110007522.4, entitled "A mineral processing method for recovering iron and sulfur from high-sulfur weak magnetic separation tailings," comprising: S100, performing strong magnetic roughing on the high-sulfur weak magnetic separation tailings to obtain strong magnetic rough concentrate; S200, regrinding the strong magnetic rough concentrate, and then performing strong magnetic roughing on the regrinded strong magnetic rough concentrate to obtain secondary strong magnetic rough concentrate; S300, performing flotation on the secondary strong magnetic rough concentrate using a positive flotation method to obtain flotation concentrate; S400, performing reverse flotation desulfurization on the flotation concentrate to obtain iron concentrate and sulfur concentrate. This invention proposes a separation process of "strong magnetic roughing-grinding-strong magnetic cleaning-positive flotation for iron extraction-reverse flotation for desulfurization", which can obtain iron concentrate with an iron grade of 61.34%, a sulfur content of 0.33% and a recovery rate of 23.27% and sulfur concentrate with a sulfur grade of 18.94%, an iron content of 50.85% and a recovery rate of 3.47%.

[0005] However, in practical application, the following problems were found: (1) The effect of strong magnetic separation is difficult to guarantee. Magnetite in the tailings will be subjected to a large magnetic force in the strong magnetic separator, making it difficult to unload and leaving residues in the media box, causing blockage of the media box and affecting the separation effect; (2) When magnetite enters the subsequent flotation process, since the positive flotation is used to separate hematite, magnetite will be lost to the tailings, resulting in a waste of resources; (3) The grinding operation cost is high. The existing method requires grinding coarse minerals to a suitable separation particle size, which requires high grinding costs and also increases the subsequent separation costs. However, the coarse minerals contain little useful minerals, even if they are processed... After fine grinding and re-selection, the recoverable useful minerals are very limited, and the output value is less than the cost. At the same time, after all the concentrate from the strong magnetic roughing is ground, the tailings particle size becomes significantly finer, which is not conducive to the subsequent filling strength and tailings dam safety. (4) It is necessary to add a total of 6 reagents, including silica inhibitor HY, iron collector CY-20, sulfur activator CYH-2, sulfur collector butyl xanthate and butyl black, and frother 2# oil. The reagent system is complex. In the positive flotation process, iron collectors need to be added to separate hematite. In the reverse flotation desulfurization process, iron inhibitors need to be added to suppress hematite. In actual application, adjustment and operation are difficult, and the amount added needs to reach HY. 1800g / t, CY-20 350g / t, CYH-2 2000g / t, butyl xanthate 300g / t, butyl black powder 100g / t, 2# oil 20g / t, the amount of reagents used is large and the cost is high; (5) the sulfur grade in the sulfur concentrate separated is only 18.94%, the grade is not high and the market popularity is low, and the iron flotation tailings are directly sent to the tailings, and the comprehensive utilization situation is not considered. Summary of the Invention

[0006] 1. The problem to be solved

[0007] In view of the numerous problems existing in the practical application of existing beneficiation methods for high-sulfur weak magnetic separation tailings, this invention provides a beneficiation method for high-sulfur weak magnetic separation tailings, which can realize diversified utilization of tailings, avoid resource waste, greatly improve the comprehensive utilization of resources, and significantly reduce beneficiation costs.

[0008] 2. Technical Solution

[0009] To solve the above problems, the present invention adopts the following technical solution.

[0010] A beneficiation method for high-sulfur, weakly magnetically separated tailings includes the following steps:

[0011] S100, coarse separation of high-sulfur weak magnetic separation tailings;

[0012] S200. The tailings after coarsening are subjected to weak magnetic roughing and strong magnetic roughing to obtain a first-stage rough concentrate.

[0013] S300: The first-stage rough concentrate is regrinded and weakly magnetically cleaned to obtain magnetite concentrate and weakly magnetically cleaned tailings;

[0014] S400: Perform strong magnetic separation on the weak magnetic separation tailings to obtain strong magnetic separation concentrate and strong magnetic separation tailings.

[0015] S500: The strong magnetic concentrate is subjected to reverse flotation desulfurization to obtain sulfur rough concentrate and desulfurization tailings. Then, the sulfur rough concentrate is subjected to a first cleaning process to obtain sulfur concentrate.

[0016] S600: The desulfurization tailings are subjected to positive flotation to obtain hematite concentrate and flotation tailings.

[0017] As a further improvement to the technical solution, the specific process of step S100 is as follows: using a sieve to coarsely separate the high-sulfur weak magnetic separation tailings, the oversize minerals are directly discharged as tailings, and the undersize minerals are sent to the next step.

[0018] As a further improvement to the technical solution, the specific process of step S200 is as follows: weak magnetic roughing is performed on the tailings after coarsening to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings. Then, strong magnetic roughing is performed on the weak magnetic roughing tailings to obtain strong magnetic roughing concentrate and strong magnetic roughing tailings. The weak magnetic roughing concentrate and strong magnetic roughing concentrate are mixed to obtain a first-stage rough concentrate. The strong magnetic roughing tailings are directly discharged.

[0019] As a further improvement to the technical solution, the magnetic field strength of the weak magnetic coarse selection is 1800-2300oe, and the magnetic field strength of the strong magnetic coarse selection is 6000-9000oe.

[0020] As a further improvement to the technical solution, the specific process of step S300 is as follows: the rough concentrate is regrinded and then subjected to weak magnetic separation to obtain weak magnetic separation concentrate, and the weak magnetic separation tailings are fed into strong magnetic separation.

[0021] As a further improvement to the technical solution, the magnetic field strength of the weak magnetic selection is 1200-1800oe.

[0022] As a further improvement to the technical solution, in step S400, the magnetic field strength of the selected strong magnet is 4000-7000oe.

[0023] As a further improvement to the technical solution, the specific process of step S500 is as follows: gangue inhibitor, sulfur collector and frother are added to the strong magnetic concentrate, the reagents and slurry are mixed evenly, and reverse flotation desulfurization is carried out using a flotation machine. After reverse flotation desulfurization, sulfur rough concentrate and desulfurized tailings are obtained. The sulfur rough concentrate is then cleaned once to obtain sulfur concentrate. The sulfur cleaned tailings are directly discharged, and the desulfurized tailings are fed into the forward flotation.

[0024] The roughing agent used CYZ-30 as the gangue inhibitor, with an addition amount of 500-900 g / t; the sulfur collector used L968, with an addition amount of 150-250 g / t; the foaming agent used was No. 2 oil, with an addition amount of 20-80 g / t; and the finishing agent was blank finishing.

[0025] As a further improvement to the technical solution, the specific process of step S600 is as follows: add gangue inhibitor and iron collector to the desulfurization tailings, mix the reagents and slurry evenly, and use a flotation machine to carry out open-circuit flotation with one rougher and one cleaner. After the cleaner flotation, hematite concentrate is obtained. The rougher and cleaner tailings of the flotation are mixed to obtain flotation tailings.

[0026] The rough selection used CYZ-30 as the gangue inhibitor, with an addition amount of 400-700 g / t, and CY-20 as the iron collector, with an addition amount of 200-600 g / t. The fine selection was a blank fine selection.

[0027] As a further improvement to the technical solution, the high-sulfur weak magnetic separation tailings are tailings with an iron grade of 10% to 18% and a sulfur content of 5% to 8%.

[0028] 3. Beneficial effects

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) The present invention provides a beneficiation method for high-sulfur weak magnetic separation tailings. The process of "coarse separation-weak magnetic roughing-strong magnetic roughing-regrinding-weak magnetic fine selection-strong magnetic fine selection-reverse flotation desulfurization-sulfur rough concentrate fine selection-desulfurized tailings positive flotation iron extraction" is used to process high-sulfur weak magnetic separation tailings. It can separate hematite concentrate with iron grade greater than 61% and sulfur content less than 0.3% from tailings with iron grade of 10% to 18% and sulfur content of 5% to 8%. At the same time, it can obtain magnetite concentrate with iron grade greater than 55% and sulfur content less than 1%, pyrite concentrate with sulfur grade greater than 35%, and flotation tailings with iron grade greater than 20% and sulfur content less than 0.5%, thereby realizing diversified utilization of tailings and greatly improving the utilization rate of tailings.

[0031] (2) The present invention provides a beneficiation method for high-sulfur weak magnetic separation tailings. Compared with the prior art, this method reduces the amount of material fed into the mill by pre-coarsening, thereby lowering grinding costs. Simultaneously, the return of coarse minerals to the tailings ensures the tailings' particle size, which is beneficial for ensuring subsequent backfill strength and tailings dam safety. The addition of weak magnetic pre-selection before strong magnetic separation ensures the smooth operation of the strong magnetic equipment. Pre-cleaning of the weak magnetic separation process avoids the loss of magnetite during flotation and its impact on subsequent steps. Prioritized desulfurization avoids the activation of sulfides, eliminating the need for sulfur activators. Furthermore, desulfurization... The process eliminates the need for iron suppression, thus simplifying the reagent system, reducing costs, and lowering operational complexity. Prioritized desulfurization of the second-stage strong magnetic concentrate effectively reduces the sulfur content of the iron positive flotation feed, thereby lowering the sulfur content of the iron positive flotation tailings and ensuring it meets the quality requirements for cement additives, thus providing conditions for its further utilization. The addition of open-circuit desulfurization cleaning improves the grade of the sulfur concentrate, meeting market demand. The staged addition of gangue inhibitors helps improve the grade of the iron concentrate and ensures the separation effect of iron positive flotation. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0033] Figure 2 This is a schematic diagram of the method flow in Example 2;

[0034] Figure 3 This is a process flow chart for Example 2. Detailed Implementation

[0035] Exemplary embodiments of the present invention are described in detail below. While these exemplary embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and various changes may be made to the invention without departing from its spirit and scope. The more detailed description of embodiments of the invention below is not intended to limit the scope of the claimed invention, but is merely illustrative and does not limit the description of the features and characteristics of the invention, in order to suggest the best mode for carrying out the invention and to enable those skilled in the art to practice it. Therefore, the scope of the invention is defined only by the appended claims.

[0036] Example 1

[0037] like Figure 1 As shown, a beneficiation method for high-sulfur weak magnetic separation tailings can achieve diversified utilization of tailings, including the following steps:

[0038] S100, Coarse Partition

[0039] For high-sulfur, weakly magnetically separated tailings, coarsening is performed. Specifically, a sieve is used to coarsely separate the tailings. The type and aperture size of the sieve are determined according to the ore properties. In this embodiment, a linear screen with an aperture size of 0.4–1 mm is used. Using a linear screen for coarsening yields coarse oversize minerals and fine undersize minerals. The oversize minerals are discarded as tailings, while the undersize minerals are sent to the next step for further processing.

[0040] In this step, approximately 10% of coarse tailings can be removed through coarse separation, alleviating the problem of coarse tailings clogging the media box of the high-gradient magnetic separator. Pre-removal of coarse tailings ensures the effective operation of the high-gradient magnetic separator. Simultaneously, coarse tailings have low grade and low content of valuable minerals; pre-removal not only improves the grade of subsequent beneficiation but also ensures more uniform tailings feeding into the mill, improving grinding efficiency. Furthermore, pre-removal of coarse minerals reduces the amount of ore fed into the mill, lowering grinding costs. The removed coarse minerals are returned to the tailings, preventing the tailings from becoming too fine due to subsequent regrinding, thus ensuring the strength of subsequent backfilling and the safety of the tailings dam.

[0041] S200, weak magnetic coarse separation + strong magnetic coarse separation

[0042] The undersize minerals are subjected to weak magnetic roughing followed by strong magnetic roughing. Specifically, a drum magnetic separator is used to perform weak magnetic roughing to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings. Then, a high-gradient magnetic separator is used to perform strong magnetic roughing on the weak magnetic roughing tailings. Finally, the weak magnetic roughing concentrate and the strong magnetic roughing concentrate are mixed to obtain a first-stage rough concentrate, which is sent to the next step for further processing, while the strong magnetic roughing tailings are discarded as tailings. In this embodiment, the magnetic field strength of the drum magnetic separator is 1800–2300 Oe, and the magnetic field strength of the high-gradient magnetic separator is 6000–9000 Oe.

[0043] This step, through weak magnetic roughing, can effectively remove strongly magnetic minerals from the undersize minerals, avoiding the situation where strongly magnetic minerals are difficult to unload in high-gradient magnetic separators. At the same time, using a high-gradient magnetic separator can remove 45% of qualified tailings, achieving early removal of tailings that can be removed, reducing the amount of ore fed into the mill, and lowering production costs.

[0044] S300, Re-polished + Weak Magnetic Selection

[0045] The primary rough concentrate undergoes regrinding followed by weak magnetic separation. Specifically, the primary rough concentrate is regrinded using a mill, and the regrinded product is then weakly magnetically separated using a drum magnetic separator. In this embodiment, the grinding particle size of -200 mesh accounts for 80-95%, and the magnetic field strength of the drum magnetic separator is 1200-1800 Oe. This step involves regrinding the primary rough concentrate using a vertical mill to obtain a grinding product of qualified particle size. Weak magnetic separation of the regrinded primary rough concentrate yields weakly magnetically separated concentrate and weakly magnetically separated tailings. The weakly magnetically separated concentrate serves as the final product, magnetite, while the weakly magnetically separated tailings undergo further processing.

[0046] In this step, the high-sulfur tailings from the weak magnetic separation are enriched by weak magnetic roughing, and after regrinding, the magnetite is essentially liberated. Further regrinding yields a product of suitable particle size, providing the necessary conditions for subsequent strong magnetic separation and flotation. Performing weak magnetic separation on the already liberated grinding product effectively removes magnetite from the rough concentrate, preventing difficulties in unloading the magnetite in high-gradient magnetic separators. It also allows for the early acquisition of magnetite of suitable grade, reducing subsequent beneficiation costs. Furthermore, since direct flotation is used to separate hematite, using weak magnetic separation to obtain concentrate in advance prevents magnetite from entering subsequent flotation processes and being lost to the tailings, thus avoiding resource waste.

[0047] S400, Strong Magnet Selection

[0048] The tailings from the weak magnetic separation process are then subjected to strong magnetic separation. Specifically, a high-gradient magnetic separator is used to perform strong magnetic separation on the tailings from the weak magnetic separation process. The tailings from the strong magnetic separation process are discarded as tailings, and the concentrate from the strong magnetic separation process is sent to the next step for further processing. In this embodiment, the magnetic field strength of the high-gradient magnetic separator is 4000–7000 Oe.

[0049] In this step, after regrinding, the hematite has been basically liberated into individual particles. Strong magnetic separation can remove another 26% of the tailings, which greatly improves the flotation grade, reduces the amount of flotation material, and lowers the reagent cost during flotation. Furthermore, by taking advantage of the non-magnetic nature of sulfates, strong magnetic tailings removal is used to remove about 95% of sulfate minerals, reducing the sulfur content of the flotation feed and thus helping to reduce the sulfur content of impurities in the iron concentrate.

[0050] S500, reverse flotation desulfurization + sulfur roughing concentrate beneficiation

[0051] The strong magnetic flux concentrate undergoes reverse flotation desulfurization followed by sulfur rough concentrate refining. Specifically, a gangue mineral depressant and a sulfur collector are first added to the strong magnetic flux concentrate, followed by the addition of a frother. The reagents and slurry are mixed thoroughly, and flotation is performed using a flotation machine to obtain a sulfur rough concentrate and desulfurized tailings. A blank refining process is then performed on the sulfur rough concentrate to obtain a sulfur concentrate and sulfur refining tailings. The sulfur concentrate is treated as a byproduct, and the sulfur refining tailings are discarded as tailings. The desulfurized tailings are sent to the next step for further processing. In this embodiment, reverse flotation desulfurization is performed on the strong magnetic flux concentrate. The gangue mineral depressant is CYZ-30, added at a rate of 600–800 g / t; the sulfur collector is L968, added at a rate of 150–250 g / t; the frother is No. 2 oil, added at a rate of 20–80 g / t; and the refining process is a blank refining process.

[0052] The existing technology involves first performing direct flotation to separate iron, followed by desulfurization of the iron concentrate. During direct flotation, the iron collector enters the iron concentrate froth along with the slurry. Subsequently, during desulfurization, iron depressants, sulfur activators, sulfur collectors, and frothers need to be added. Because of the presence of the iron collector in direct flotation, a large amount of depressant is required to ensure that the iron is suppressed, resulting in high reagent costs and significant operational and implementation difficulties.

[0053] Compared with existing technologies, this preferential desulfurization method eliminates the need for activators to activate sulfides and inhibitors to suppress iron minerals, saving on the costs of activators and inhibitors and reducing implementation difficulty. Furthermore, using the novel reagent L968 with high-efficiency collecting properties for desulfurization not only achieves excellent sulfide removal but also reduces the number of reagents required, further simplifying implementation. Simultaneously, adding inhibitors to gangue minerals before reverse flotation reduces gangue mineral uplift during desulfurization, which is beneficial for sulfur concentrate refining. The finer refining of the sulfur rough concentrate yields qualified by-product sulfur concentrate. Thirdly, the preferential desulfurization of the second-stage strong magnetic concentrate effectively reduces the sulfur content of the iron positive flotation feed, thereby reducing the sulfur content of the iron positive flotation tailings and meeting the quality requirements for cement additives, thus providing conditions for its further utilization.

[0054] S600, Direct Flotation

[0055] Direct flotation is performed on desulfurization tailings. Specifically, gangue inhibitors and iron collectors are added to the desulfurization tailings. The reagents and slurry are mixed evenly in a stirred tank, and open-circuit direct flotation is performed using a flotation machine with one rougher and one cleaner. After direct flotation cleaning, hematite concentrate is obtained as the product. The rougher tailings and cleaner tailings are mixed as the by-product flotation tailings. In this embodiment, direct flotation is performed on the desulfurization tailings. The gangue inhibitor is CYZ-30, with an addition amount of 500-700 g / t, and the iron collector is CY-20, with an addition amount of 200-600 g / t. The cleaning is blank cleaning.

[0056] Compared with existing technologies, this step, combined with step S500, involves staged dosing of the gangue inhibitor, which is more conducive to improving the flotation efficiency of iron. It is worth further noting that the flotation tailings are characterized by high iron and low sulfur content, and the iron minerals are mainly hematite, making them ideal cement additives that can be sold as by-products. Furthermore, due to the priority desulfurization in this technology, both the hematite agent and the flotation tailings have even lower sulfur content.

[0057] It is worth mentioning that in this embodiment, in steps S200 to S400, multiple magnetic separations are performed on the tailings, and the magnetic field strength of each magnetic separation stage is individually limited. This limitation of magnetic field strength is a design of this invention combined with the improvement of the overall mineral processing process. Then, it is further combined with the flotation steps of S500 and S600 to simplify the reagent addition step and reduce costs, while achieving better diversified mineral processing results. It is not a single conventional design.

[0058] In this embodiment, four products—magnetite concentrate, hematite concentrate, sulfur concentrate, and flotation tailings—are obtained using the above method. The obtained magnetite concentrate has a grade of 55.31%, a sulfur content of 0.89%, and an iron recovery rate of 5.31%; the hematite concentrate has a grade of 61.52%, a sulfur content of 0.21%, and an iron recovery rate of 21.24%; the sulfur concentrate has a sulfur grade of 36.52%, an iron content of 39.74%, and a sulfur recovery rate of 3.42%; and the flotation tailings have an iron grade of 23.51%, a sulfur content of 0.32%, and an iron recovery rate of 16.56%.

[0059] In summary, the beneficiation method for high-sulfur weak magnetic separation tailings in this embodiment is suitable for separating hematite concentrate with an iron grade greater than 61% and a sulfur content less than 0.3% from tailings with an iron grade of 10% to 18% and a sulfur content of 5% to 8%. At the same time, it also yields magnetite concentrate with an iron grade greater than 55% and a sulfur content less than 1%, pyrite concentrate with a sulfur grade greater than 35%, and flotation tailings with an iron grade greater than 20% and a sulfur content less than 0.5%, thus realizing diversified utilization of tailings and greatly improving the tailings utilization rate.

[0060] Compared with existing technologies, this embodiment reduces the amount of material fed into the mill by pre-coarsening, thereby lowering grinding costs. Simultaneously, returning coarse minerals to the tailings ensures the tailings' particle size, which is beneficial for ensuring subsequent backfill strength and tailings dam safety. The addition of weak magnetic pre-selection before strong magnetic separation ensures the smooth operation of the strong magnetic equipment. Pre-cleaning with weak magnetic separation avoids the loss of magnetite during flotation and its impact on subsequent steps. Prioritized desulfurization avoids the activation of sulfur minerals and the inhibition of iron minerals, eliminating the need for sulfur activators and iron depressants, reducing costs and operational difficulty. It also creates conditions for reducing the sulfur content of hematite concentrate and flotation tailings during positive flotation. The addition of open-circuit desulfurization cleaning improves the grade of sulfur concentrate. The segmented addition of gangue depressants helps improve the grade of sulfur concentrate and ensures the separation effect of iron positive flotation. Based on the properties of the iron positive flotation tailings, cement additives are used for comprehensive utilization, improving tailings utilization rate.

[0061] Example 2

[0062] This embodiment uses the beneficiation method of high-sulfur weak magnetic separation tailings from Example 1. The high-sulfur weak magnetic separation tailings were taken from an iron ore beneficiation plant. The results of multi-element chemical analysis of the tailings are shown in Table 1.

[0063] Table 1. Results of multi-element chemical analysis of tailings (%)

[0064]

[0065] The results of iron phase analysis of the tailings are shown in Table 2.

[0066] Table 2. Phase analysis results of raw iron ore (%)

[0067]

[0068] The results of sulfur phase analysis of the tailings are shown in Table 3.

[0069] Table 3. Results of sulfur phase analysis in tailings (%)

[0070] Sulfur phase Sulfur in sulfides Sulfur in sulfate elemental sulfur total content 1.96 3.73 0.01 5.70 Distribution rate 34.39 65.44 0.17 100.00

[0071] As shown in Tables 1, 2, and 3, the main recoverable useful iron minerals in high-sulfur weak magnetic separation tailings are magnetite, hematite, and pyrite.

[0072] like Figure 2 and Figure 3 As shown, the mineral processing method of Example 1 was used to treat the above-mentioned high-sulfur weak magnetic separation tailings, as follows:

[0073] S100. Use a linear screen to coarsely separate the high-sulfur weak magnetic separation tailings to obtain coarse oversize minerals and fine undersize minerals. The oversize minerals are discarded as tailings (T1), and the undersize minerals enter step 200. The screen aperture size is 0.5 mm.

[0074] S200. The undersize minerals are subjected to weak magnetic roughing using a drum magnetic separator, and the tailings from the weak magnetic roughing are subjected to strong magnetic roughing using a high gradient magnetic separator. The weak magnetic roughing concentrate and the strong magnetic roughing concentrate are mixed to obtain a first-stage rough concentrate, which enters step 300. The tailings from the strong magnetic roughing are discarded as tailings in T2. ​​The magnetic field strength of the drum magnetic separator is 2000oe, and the magnetic field strength of the high gradient magnetic separator is 7000oe.

[0075] S300: The first-stage rough concentrate is regrinded using a vertical mill to obtain a grinding product of qualified particle size. The regrinded first-stage rough concentrate is then subjected to weak magnetic separation to obtain weak magnetic separation concentrate and weak magnetic separation tailings. The weak magnetic separation concentrate is the final product T5, and the weak magnetic separation tailings enter step 400. In this process, the grinding particle size is -200 mesh, accounting for 90%, and the magnetic field strength of the drum magnetic separator is 1500oe.

[0076] S400: Use a high-gradient magnetic separator to perform strong magnetic separation on the weak magnetic separation tailings. The strong magnetic separation tailings are discarded as tailings (T3). The strong magnetic separation concentrate enters step 500. The magnetic field strength of the high-gradient magnetic separator is 6000oe.

[0077] S500: First, add a gangue mineral inhibitor and a sulfur collector to the strong magnetic concentrate. Then, add a frother. Mix the reagents and slurry. Use a flotation machine to obtain a floating sulfur rough concentrate and desulfurized tailings. Perform blank cleaning on the floating sulfur rough concentrate to obtain a sulfur concentrate and sulfur-refined tailings. The sulfur concentrate is used as a by-product T6, and the sulfur-refined tailings are discarded as tailings T4. The desulfurized tailings enter step 600. In this process, the gangue mineral inhibitor used in the roughing process is CYZ-30, with an addition amount of 700 g / t. The sulfur collector used is L968, with an addition amount of 200 g / t. The frother used is No. 2 oil, with an addition amount of 50 g / t. The cleaning process is blank cleaning.

[0078] S600. Add gangue inhibitor and iron collector to desulfurization tailings. Mix the reagents and slurry evenly using a stirring tank. Perform open-circuit flotation with one rougher and one cleaner. After the cleaner flotation, hematite concentrate T7 is obtained. The rougher tailings and cleaner tailings are mixed to form the by-product flotation tailings T8. The rougher gangue inhibitor is CYZ-30, with an addition amount of 500-700 g / t. The iron collector is CY-20, with an addition amount of 200-600 g / t. The cleaner is blank cleaner.

[0079] In this embodiment, the high-sulfur weak magnetic separation tailings were separated using the method of Example 1. The obtained magnetite concentrate had a grade of 55.31%, a sulfur content of 0.89%, and an iron recovery rate of 5.31%; hematite concentrate had a grade of 61.52%, a sulfur content of 0.21%, and an iron recovery rate of 21.24%; sulfur concentrate had a sulfur grade of 36.52%, an iron content of 39.74%, and a sulfur recovery rate of 3.42%; and flotation tailings had an iron grade of 23.51%, a sulfur content of 0.32%, and an iron recovery rate of 16.56%. Compared with the prior art, this technology has high iron and sulfur recovery rates, low sulfur content in hematite, a simple reagent system, low production costs, and deep processing based on the characteristics of intermediate products, achieving diversified utilization of tailings and demonstrating significant advantages.

[0080] The examples described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention.

Claims

1. A beneficiation method for high-sulfur weak magnetic separation tailings, characterized in that: The high-sulfur, weakly magnetically separated tailings are tailings with an iron content of 10%-18% and a sulfur content of 5%-8%; the process includes the following steps: S100. Use a sieve to coarse the high-sulfur weak magnetic separation tailings. The sieve aperture size is 0.4-1mm. The oversize minerals are directly discharged as tailings, and the undersize minerals are sent to the next step. S200. The tailings after coarsening are subjected to weak magnetic roughing with a magnetic field strength of 1800-2300oe to obtain weak magnetic roughing concentrate and weak magnetic roughing tailings. Then, the weak magnetic roughing tailings are subjected to strong magnetic roughing with a magnetic field strength of 6000-9000oe to obtain strong magnetic roughing concentrate and strong magnetic roughing tailings. The weak magnetic roughing concentrate and strong magnetic roughing concentrate are mixed to obtain a first-stage rough concentrate. The strong magnetic roughing tailings are directly discharged. S300: The first-stage coarse concentrate is regrinded, with the grinding particle size of -200 mesh accounting for 80%-95%, and then weak magnetic separation is performed with a magnetic field strength of 1200-1800oe to obtain weak magnetic separation concentrate and weak magnetic separation tailings. S400: Strong magnetic separation is carried out on the weak magnetic separation tailings with a magnetic field strength of 4000-7000oe to obtain strong magnetic separation concentrate and strong magnetic separation tailings. S500: The strong magnetic concentrate is subjected to reverse flotation desulfurization to obtain sulfur rough concentrate and desulfurization tailings. Then, the sulfur rough concentrate is subjected to a first cleaning process to obtain sulfur concentrate. S600: The desulfurization tailings are subjected to positive flotation to obtain hematite concentrate and flotation tailings.

2. The method according to claim 1, characterized in that: In step S500, the roughing gangue inhibitor is CYZ-30, with an addition amount of 500-900 g / t; the sulfur collector is 150-250 g / t; the foaming agent is No. 2 oil, with an addition amount of 20-80 g / t; and the finishing process is blank finishing. In step S600, the roughing gangue inhibitor is CYZ-30, with an addition amount of 400-700 g / t; the iron collector is CY-20, with an addition amount of 200-600 g / t; and the finishing process is blank finishing.

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