A beneficiation method for deep separation and enrichment of valuable components in iron rough concentrate

Abstract

The application discloses a beneficiation method for deep separation and enrichment of valuable components in iron rough concentrate, and belongs to the technical field of mineral processing. The method is used for complex associated magnetite rough concentrate, and sulfur minerals are preferentially separated through desulfurization flotation. After fine grinding, the desulfurization tailings are subjected to three times of weak magnetic separation to obtain low-sulfur iron concentrate. The final iron concentrate is obtained through reverse flotation and deep impurity removal. After concentration, the magnetic separation tailings are subjected to mixed flotation of tungsten and fluorite with sodium carbonate as a pH regulator, water glass as an inhibitor, lead nitrate as an activator, and SZW-01 and SZY-01 as synergistic collectors. The mixed concentrate is subjected to heating and selective separation to obtain tungsten concentrate and fluorite concentrate. The application breaks through the limitation of single traditional magnetic separation process, realizes efficient separation and enrichment of iron, tungsten and fluorite valuable components in magnetite rough concentrate, and has the advantages of high iron concentrate quality, good comprehensive recovery of associated elements, high water resource recycling rate and the like, and is suitable for efficient comprehensive utilization of complex multi-metal associated magnetite.

Description

Technical Field

[0001] This invention belongs to the technical field of ore processing, specifically relating to a mineral processing method for deep separation and enrichment of valuable components in iron ore concentrate. Background Technology

[0002] Magnetite, as an important iron ore resource, has always been a focus of attention in the mining industry for its efficient beneficiation and comprehensive utilization. Existing magnetite beneficiation technologies typically employ simple magnetic separation processes to obtain iron concentrate, but these have many limitations. For complex polymetallic ores with associated magnetite, problems often arise such as excessive sulfur content in the iron concentrate obtained through weak magnetic separation, low iron concentrate grade, and insufficient recovery and utilization of valuable elements. Especially when processing complex magnetite containing multiple associated valuable elements, existing technologies show significant shortcomings.

[0003] For a complex polymetallic tungsten-molybdenum-bismuth-fluorite mine, with approximately 2% associated strongly magnetic minerals, a magnetite rough concentrate is first obtained through weak magnetic separation before separating the tungsten, molybdenum, bismuth, and fluorite minerals. This iron rough concentrate has complex characteristics: approximately 70% is -0.074mm, with TFe grade 38%, S grade 5%, WO3 grade 0.08%, CaF2 grade 10%, SiO2 grade 22%, and CaCO3 grade approximately 5%. The current processing method involves grinding the ore to -0.045mm (80%) using a vertical stirred mill, followed by multiple weak magnetic separations to obtain the iron concentrate. Figure 1 As shown. However, the iron concentrate obtained by this method has a TFe grade of only 52% and contains as much as 8% S, resulting in low product value. At the same time, due to the fine particle size of tungsten and fluorite, they are not effectively recovered in the existing process and ultimately end up in the tailings dam, causing resource waste.

[0004] Existing technologies for magnetite upgrading suffer from the following main problems: First, effective desulfurization measures are not employed; relying solely on magnetic separation to improve iron concentrate grade results in severely excessive sulfur content in the iron concentrate, impacting product quality. Second, insufficient liberation of iron minerals limits further improvement in iron grade. Third, effective separation methods for fine-grained minerals are lacking. Furthermore, in terms of associated element recovery, the comprehensive recovery of tungsten and fluorite is almost entirely neglected, and a dedicated process design is lacking.

[0005] In recent years, some studies have attempted to solve the challenges in magnetite beneficiation, such as the magnetic field screening method developed by the Zhengzhou Institute of Comprehensive Utilization. This technology can improve the grade of iron concentrate while coarsening the grinding particle size and increasing separation efficiency. However, this technology is mainly aimed at the separation of single iron minerals and is still insufficient for complex polymetallic ores. Other studies have shown that a combined magnetic separation-flotation process can effectively process sulfur-bearing magnetite, but it still does not consider the comprehensive recovery of associated elements such as tungsten and fluorite.

[0006] In the field of tungsten and fluorite recovery technology, existing methods typically face problems such as complex processes and low recovery rates due to fine particle embedding. For example, while some beneficiation processes for muddy tungsten polymetallic ores can recover scheelite and fluorite, they require complex combined separation processes such as magnetic separation, flotation, and centrifugation, and the resulting tungsten concentrate grade and recovery rate are not ideal. In addition, although the traditional Petrov process can be used for tungsten ore beneficiation, its direct application to magnetite tailings yields poor tungsten recovery results, mainly due to the significant differences in feed properties.

[0007] Therefore, there is an urgent need to develop a mineral processing method that can efficiently improve the quality of magnetite rough and concentrate and comprehensively recover valuable elements, and can simultaneously achieve multiple objectives such as increasing iron grade, reducing sulfur content, and efficiently recovering tungsten and fluorite, thereby maximizing the comprehensive utilization of resources and economic benefits. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a mineral processing method for deep separation and enrichment of valuable components in iron crude concentrate, so as to solve the problems mentioned in the background art or achieve better technical effects.

[0009] To solve the above-mentioned technical problems, the inventors derived the technical solution of this invention through practice and summarization. This invention discloses a mineral processing method for deep separation and enrichment of valuable components in iron ore concentrate. It adopts a four-stage process coupling technology of desulfurization-iron extraction-impurity removal-recovery. The iron ore concentrate is first desulfurized and then iron extracted to reduce the interference of sulfur minerals on the magnetic separation process. Then, deep impurity removal is carried out through reverse flotation to improve the quality of iron ore concentrate in a stepwise manner.

[0010] The entire process includes the following steps:

[0011] S1: Add water to the iron crude concentrate to make a slurry, add desulfurization flotation reagents and carry out flotation to obtain high-sulfur iron concentrate and desulfurization tailings;

[0012] S2: The desulfurized tailings obtained from S1 are ground and then subjected to weak magnetic separation to obtain low-sulfur iron concentrate and magnetic separation tailings.

[0013] S3: After adjusting the pH of the low-sulfur iron concentrate obtained from S2, a collector is added for reverse flotation. The froth product is returned to the grinding mill for further grinding, and the bottom product is the final iron concentrate.

[0014] S4: After concentrating the magnetic separation tailings obtained in S2, add modifier, inhibitor, activator and synergist to carry out mixed flotation of tungsten and fluorite. After roughing, scavenging and cleaning, tungsten and fluorite mixed concentrate is obtained.

[0015] S5: The tungsten-fluorite mixed concentrate obtained in S4 is separated by heated flotation. The flotation foam product is tungsten concentrate, and the bottom product is fluorite concentrate.

[0016] Further, in S1, the desulfurization flotation reagents include oxalic acid, copper sulfate, sodium butyl xanthate, and butylamine black, wherein the dosage of oxalic acid is 400~500 g / t, the dosage of copper sulfate is 80~120 g / t, the dosage of sodium butyl xanthate is 40~60 g / t, and the dosage of butylamine black is 8~12 g / t; the pulp concentration is 35%~40%.

[0017] Furthermore, in S2, the fineness of the grinding is -0.039mm, accounting for 90%~95%; the weak magnetic separation is a three-stage weak magnetic separation.

[0018] Furthermore, in S3, the reverse flotation uses sodium carbonate to adjust the pulp pH to 8.0~8.5, and SZY-01 is used as the collector, with an SZY-01 dosage of 50~70g / t; the SZY-01 is a modified oleic acid collector, which is emulsified and prepared by oleic acid, emulsifier, diesel oil and kerosene in a mass ratio of 70%:20%:5%:5%.

[0019] Furthermore, in step S4, the magnetic separation tailings are concentrated to a slurry concentration of 35% to 40%.

[0020] Further, in step S4, the modifier is sodium carbonate, with a dosage of 800 g / t; the inhibitor is water glass, with a dosage of 1200 g / t; and the activator is lead nitrate, with a dosage of 400-550 g / t.

[0021] Furthermore, in S4, the synergistic collector is a compound agent of SZW-01 and SZY-01, with the dosage of SZW-01 being 280~350g / t and the dosage of SZY-01 being 35~50g / t; SZW-01 is a benzohydroxyoxime acid multiligand collector.

[0022] Furthermore, the hydroxamic acid group in the SZW-01 molecule has a strong complexing ability on the tungsten-oxygen active sites on the surface of tungsten minerals, and can form a stable five-membered ring chelate.

[0023] The carboxylic acid group and long-chain alkane structure in the SZY-01 molecule exhibit excellent coordination adsorption and hydrophobic covering ability for calcium ions on the fluorite surface.

[0024] When combined, the two can form a composite film structure on the surface of tungsten and fluorite.

[0025] Furthermore, in S4, the tungsten-fluorite mixed flotation process consists of one roughing, two scavenging, and three cleaning stages; the overflow water generated from the magnetic separation tailings concentration is returned to the magnetic separation and flotation operations for recycling, thus realizing the recycling of mineral processing water.

[0026] Furthermore, in S5, the heated flotation adopts the Petrov process for heated fine flotation, the flotation temperature is 90~95℃, the holding time is 0.5~1.5h, and the heated flotation reagents include NaOH, water glass and SZY-01.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) This invention uses a four-stage process coupling technology of “desulfurization-iron extraction-impurity removal-recovery”. Through the process design of “desulfurization first and then iron extraction”, it effectively solves the interference of sulfur minerals on the magnetic separation process; and then through reverse flotation for deep impurity removal, it achieves a step-by-step improvement in the quality of iron concentrate. This process breaks through the limitations of traditional magnetic separation, which is simple and extensive, and realizes the orderly separation of complex components.

[0029] (2) After the magnetic separation tailings are concentrated, a synergistic flotation reagent system (SZW-01 and SZY-01 used together) is adopted, and combined with the Petrov process for heated flotation, to achieve efficient separation of fine-grained tungsten and fluorite. This technology is particularly suitable for mineral systems with fine-grained disseminated particles and similar floatability.

[0030] (3) By strictly controlling the grinding fineness to 90%~95% of -0.039mm, and combining the staged addition of reagents and the adjustment of flotation conditions, the degree of liberation and flotation recovery of fine minerals have been significantly improved, overcoming the technical bottleneck of serious loss of fine minerals in the traditional process.

[0031] (4) Strong technical adaptability. This technology can be widely applied to the beneficiation process of magnetite with various complex associated valuable elements, especially for fine-grained tungsten, fluorite and other minerals, which have strong adaptability and broad prospects for promotion and application. Attached Figure Description

[0032] Figure 1 This is the original iron ore beneficiation process flow;

[0033] Figure 2 This is a flow chart of the iron concentrate beneficiation process for valuable components according to the present invention. Detailed Implementation

[0034] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0035] Unless otherwise specified, all raw materials or reagents used in the following examples are commercially available products.

[0036] This invention provides a process for upgrading magnetite rough concentrate and comprehensively recovering tungsten and fluorite. The overall process flow includes two core parts: magnetite upgrading and comprehensive recovery of tungsten and fluorite; Figure 2As shown, the steps are as follows:

[0037] (1) Upgrading stage of magnetite rough and concentrate

[0038] S1: Magnetite rough concentrate (70% fineness -0.074mm, 38% iron grade, 5% sulfur grade) is mixed with water to form a slurry with a concentration of 35%~40%. Oxalic acid, copper sulfate, sodium butyl xanthate, and butylamine black are added as beneficiation reagents. After sufficient reaction, the slurry is fed into a flotation machine to obtain high-sulfur iron concentrate (60% iron grade, 20% sulfur grade) and desulfurized tailings. This step separates most of the sulfur minerals through preferential flotation, laying the foundation for subsequent iron grade improvement.

[0039] S2: The desulfurized tailings are fed into a ball mill and ground to 90%~95% of the material, which is -0.039mm. Then, three weak magnetic separations are performed to obtain low-sulfur iron concentrate (60% iron grade and 0.40% sulfur grade). The fine grinding operation at this stage aims to fully dissociate the intergrowth of iron minerals and gangue minerals, creating favorable conditions for subsequent efficient separation.

[0040] S3: Subsequently, the low-sulfur iron concentrate is fed into a flotation machine for reverse flotation to remove impurities by adding sodium carbonate (pH adjusted to 8.0-8.5) and SZY-01 (a modified oleic acid, mainly composed of oleic acid, emulsifier, diesel oil, and kerosene in a 70%:20%:5%:5% ratio). The froth product, which is a lean intergrowth of iron and gangue minerals, is returned to the grinding mill for regrinding. The bottom product is the final iron concentrate (65% iron, 0.3% sulfur). The reverse flotation process effectively removes gangue minerals such as silicates, further improving the quality of the iron concentrate.

[0041] (2) Comprehensive recycling stage of tungsten and fluorite

[0042] S4: The magnetic separation tailings generated during the magnetite upgrading process are concentrated in a thickening tank and concentrated to a pulp concentration of 35%~40%. Then, sodium carbonate (800g / t), water glass (1200g / t), lead nitrate (400g / t), SZW-01 (300g / t, a benzoyl hydroxamic acid multiligand collector) and SZY-01 (40g / t) are added for tungsten and fluorite mixed flotation. After one roughing, two scavenging and three cleaning processes, a tungsten-fluorite mixed concentrate is obtained.

[0043] S5: In the above mixed flotation step, sodium carbonate is used to adjust the pH value of the pulp, water glass is used as an inhibitor of gangue such as silicates, lead nitrate is an activator of tungsten minerals, and benzohydroxyxamic acid and SZY-01 are used as collectors to selectively collect tungsten and fluorite minerals.

[0044] S6: The tungsten-fluorite mixed concentrate is then subjected to heated flotation using the Petrov process. The flotation froth product is the tungsten concentrate (60% tungsten grade), and the bottom product is the fluorite concentrate (93% fluorite grade). The heated flotation here can effectively separate tungsten minerals and fluorite, solving the separation problem caused by their similar floatability. The overflow water from the magnetic separation tailings is reused for magnetic separation and flotation operations.

[0045] Synergistic mechanism of mixed collectors:

[0046] In the tungsten and fluorite mixed flotation stage described in this invention, a composite reagent of SZW-01 (benzoyl hydroxamic acid collector) and SZY-01 (modified oleic acid collector) is used. Through a triple mechanism of "adsorption complementarity - foam synergy - interface regulation," the two reagents achieve efficient and selective co-collection of fine-grained tungsten minerals and fluorite. The specific mechanism is as follows:

[0047] a. Selective adsorption and complementary molecular structures:

[0048] The hydroxamic acid group (-C(=NOH)OH) in the SZW-01 molecule has a strong complexing ability with the tungsten-oxygen active sites on the surface of tungsten minerals, and can form a stable five-membered ring chelate to achieve highly selective chemical adsorption of tungsten minerals.

[0049] The carboxylic acid group (-COOH) and long-chain alkane structure in the SZY-01 molecule exhibit excellent coordination adsorption and hydrophobic covering ability for calcium ions on the fluorite surface.

[0050] When combined, the two can form a composite membrane structure of "partitioned adsorption and overall hydrophobicity" on the surface of tungsten and fluorite, which not only avoids the decline in recovery rate caused by competitive adsorption, but also enhances the overall floatability of mineral particles.

[0051] b. Foam structure optimization and mineralization enhancement:

[0052] The emulsifier component (20%) contained in SZY-01 can significantly reduce the surface tension of the slurry and improve the spreading and adhesion of fine mineral particles on the surface of bubbles;

[0053] The multi-ligand properties of SZW-01 enhance the strength and density of the mineral-bubble attachment site;

[0054] The synergy of the two results in finer, more stable flotation foam with full mineralization, which is beneficial for the recovery of ultrafine particles with a particle size of -0.039mm. This effectively solves the problems of weak collection ability of traditional single collectors for fine mineral particles and high foam brittleness.

[0055] c. Regulation of interfacial electrical properties and hydration film

[0056] In a weakly alkaline mineral slurry environment regulated by sodium carbonate (pH=8.0~8.5), both SZW-01 and SZY-01 exist in anionic form, which is compatible with the surface electrical properties of tungsten and fluorite, and is adsorbed through electrostatic interaction.

[0057] Combining these methods can further weaken the hydration film strength on the mineral surface and enhance the hydrophobic aggregation effect, thereby improving the flotation rate and recovery rate.

[0058] d. Seamless integration with subsequent heating and refining processes

[0059] This composite reagent system not only achieves the initial co-harvest of tungsten and fluorite, but its adsorption layer also exhibits differentiated desorption characteristics under subsequent Petrov process heating (95°C) and high-alkali environments: SZY-01 further enhances the adsorption selectivity of fluorite under high temperature and high-alkali conditions, while SZW-01 has relatively stable adsorption of tungsten minerals, thus creating thermodynamic and kinetic conditions for achieving efficient separation of tungsten and fluorite.

[0060] Example 1

[0061] A process for upgrading magnetite rough concentrate and comprehensively recovering tungsten and fluorite, such as... Figure 1 As shown, the steps are as follows:

[0062] S1: Desulfurization flotation:

[0063] Magnetite rough concentrate (70% fineness -0.074mm, 38% iron, 5% sulfur, 0.08% WO3, 10% CaF2, 22% SiO2, and 5% CaCO3) was mixed with water to form a slurry with a concentration of 38%. Oxalic acid (450g / t), copper sulfate (100g / t), sodium butyl xanthate (50g / t), and butylamine black powder (10g / t) were added. After sufficient reaction, the slurry was floated in a flotation machine to obtain high-sulfur iron concentrate (60% iron and 15% sulfur) and desulfurized tailings for the next stage.

[0064] S2: Fine grinding and weak magnetic separation:

[0065] The desulfurization tailings are fed into a ball mill and ground to -0.039mm (92%), and then subjected to three weak magnetic separations to obtain low-sulfur iron concentrate (60% iron and 0.40% sulfur).

[0066] S3: Reverse flotation for impurity removal:

[0067] Low-sulfur iron concentrate is de-impurified by adding sodium carbonate (400g / t), adjusting the pH to 8.2, adding collector SZY-01 (60g / t), and then entering the flotation machine for reverse flotation. The froth product is a lean intergrowth of iron and gangue minerals, which is returned to the grinding mill for regrinding. The bottom product is the final iron concentrate (65% iron and 0.3% sulfur).

[0068] S4: Tungsten-fluorite mixed flotation:

[0069] The magnetic separation tailings generated during the magnetite upgrading process are concentrated in a thickening tank and concentrated to a pulp concentration of 38%. Then, sodium carbonate (800g / t), water glass (1200g / t), lead nitrate (500g / t), collector SZW-01 (300g / t) and SZY-01 (40g / t) are added for tungsten and fluorite mixed flotation. After one roughing, two scavenging and three cleaning processes, a tungsten-fluorite mixed concentrate is obtained. The mixed concentrate is then subjected to heated cleaning.

[0070] S5: Heated Selection (Petrov Method)

[0071] The above-mentioned tungsten-fluorite mixed concentrate was subjected to heated flotation using the Petrov process. The temperature was 95℃ and held for 1 hour. The reagents were NaOH (1000g / t), water glass (75000g / t), and SZY-01 (600g / t). The flotation froth product yielded tungsten concentrate (WO3 grade 60%, recovery rate 70%), and the bottom product was fluorite concentrate (CaF2 grade 93%, recovery rate 68%).

[0072] In this embodiment, the iron concentrate: TFe is increased from 38% to 65%, and S is reduced from 5% to 0.3%; tungsten and fluorite are efficiently recovered, realizing resource utilization; all overflow water is reused, with a water saving rate of >80%.

[0073] Example 2

[0074] A process for upgrading magnetite rough concentrate and comprehensively recovering tungsten and fluorite includes the following steps:

[0075] S1: Desulfurization flotation:

[0076] Magnetite rough concentrate (75% fineness -0.074mm, 45% iron, 8% sulfur, 0.05% WO3, 8% CaF2, and 18% SiO2) was mixed with water to form a slurry with a concentration of 38%. Oxalic acid (500g / t), copper sulfate (120g / t), sodium butyl xanthate (60g / t), and butylamine black powder (12g / t) were added. After sufficient reaction, the slurry was floated in a flotation machine to obtain high-sulfur iron concentrate (58% iron and 22% sulfur) and desulfurized tailings for the next stage.

[0077] S2: Fine grinding and weak magnetic separation:

[0078] The desulfurization tailings are fed into a ball mill and ground to -0.039mm (94%), and then subjected to three weak magnetic separations to obtain low-sulfur iron concentrate (62% iron and 0.45% sulfur).

[0079] S3: Reverse flotation for impurity removal:

[0080] The pH of the low-sulfur iron concentrate is adjusted to 8.5 by adding sodium carbonate. Collector SZY-01 (70g / t) is introduced into the flotation machine for reverse flotation to remove impurities. The froth product is a lean intergrowth of iron and gangue minerals, which is returned to the grinding mill for re-grinding. The bottom product is the final iron concentrate (66% iron and 0.25% sulfur).

[0081] S4: Tungsten-fluorite mixed flotation:

[0082] The magnetic separation tailings generated during the magnetite upgrading process are concentrated in a thickening tank and concentrated to a pulp concentration of 38%. Then, sodium carbonate (800g / t), water glass (1200g / t), lead nitrate (550g / t), collector SZW-01 (350g / t) and SZY-01 (50g / t) are added for tungsten and fluorite mixed flotation. After one roughing, two scavenging and three cleaning processes, a tungsten-fluorite mixed concentrate is obtained. The mixed concentrate is then subjected to heated cleaning.

[0083] S5: Heated Selection (Petrov Method)

[0084] The aforementioned tungsten-fluorite mixed concentrate was subjected to heated flotation using the Petrov process. The temperature was 95℃ and held for 1 hour. The reagents were NaOH (1000g / t), water glass (75000g / t), and SZY-01 (600g / t). The flotation froth product yielded tungsten concentrate (WO3 grade 58%, recovery rate 65%), while the bottom product was fluorite concentrate (CaF2 grade 91%, recovery rate 70%).

[0085] In this embodiment, the sulfur content of the iron concentrate is significantly reduced from 8% to 0.25%, and the iron grade is increased to 66%; the recovery rates of tungsten and fluorite are stable, making it suitable for complex high-sulfur ores; the process is highly adaptable, and the reagent regime is adjustable.

[0086] Example 3

[0087] A process for upgrading magnetite rough concentrate and comprehensively recovering tungsten and fluorite includes the following steps:

[0088] S1: Desulfurization flotation:

[0089] Magnetite rough concentrate (65% fineness -0.074mm, 32% iron, 4% sulfur, 0.12% WO3, 15% CaF2, and 25% SiO2) was mixed with water to form a slurry with a concentration of 35%. Oxalic acid (400g / t), copper sulfate (80g / t), sodium butyl xanthate (40g / t), and butylamine black powder (8g / t) were added. After sufficient reaction, the slurry was floated in a flotation machine to obtain high-sulfur iron concentrate (58% iron and 22% sulfur) and desulfurized tailings (2.5% sulfur content) for the next stage.

[0090] S2: Fine grinding and weak magnetic separation:

[0091] The desulfurization tailings are fed into a ball mill and ground to -0.039mm (90%), and then subjected to three weak magnetic separations to obtain low-sulfur iron concentrate (58% iron and 0.5% sulfur).

[0092] S3: Reverse flotation for deep iron extraction:

[0093] The pH of the low-sulfur iron concentrate is adjusted to 8.0 by adding sodium carbonate (350g / t). Collector SZY-01 (50g / t) is introduced into the flotation machine for reverse flotation to remove impurities. The froth product is a lean intergrowth of iron and gangue minerals, which is returned to the grinding mill for regrinding. The bottom product is the final iron concentrate (63% iron and 0.35% sulfur).

[0094] S4: Tungsten-fluorite mixed flotation:

[0095] The magnetic separation tailings generated during the magnetite upgrading process are concentrated in a thickening tank and concentrated to a pulp concentration of 38%. Then, sodium carbonate (800g / t), water glass (1200g / t), lead nitrate (550g / t), collector SZW-01 (280g / t) and SZY-01 (35g / t) are added for tungsten and fluorite mixed flotation. After one roughing, two scavenging and three cleaning processes, a tungsten-fluorite mixed concentrate is obtained. The mixed concentrate is then subjected to heated cleaning.

[0096] S5: Heated Selection (Petrov Method)

[0097] The aforementioned tungsten-fluorite mixed concentrate was subjected to heated flotation using the Petrov process. The temperature was 95℃ and held for 1 hour. The reagents were NaOH (1000g / t), water glass (75000g / t), and SZY-01 (600g / t). The flotation froth product yielded tungsten concentrate (WO3 grade 62%, recovery rate 75%), while the bottom product was fluorite concentrate (CaF2 grade 94%, recovery rate 72%).

[0098] In this embodiment, the iron concentrate: TFe is increased from 32% to 63%, and S is reduced from 8% to below 0.35%; tungsten and fluorite are efficiently recovered, realizing resource utilization; all overflow water is reused, with a water saving rate of >80%.

[0099] Comparative Example 1

[0100] A process for beneficiating raw iron ore concentrate, such as Figure 1 As shown, the steps are as follows:

[0101] S1: Feed the iron concentrate (70% fineness -0.074mm, 38% TFe, 5% S, 0.08% WO3, 10% CaF2, 22% SiO2, and 5% CaCO3) into the vertical stirred mill.

[0102] S2: After grinding to a fineness of -0.045mm accounting for 80%, perform multiple weak magnetic separations (usually three or four weak magnetic separations).

[0103] S3: Magnetic concentrate is used as the final iron concentrate product, and magnetic tailings are directly discharged into the tailings pond.

[0104] The process flow does not include any desulfurization flotation operation, reverse flotation impurity removal operation, or recovery of associated valuable elements.

[0105] The iron concentrate indices obtained from Examples 1-3 and Comparative Example 1 were compared, and the results are shown in Table 1 below.

[0106] Table 1. Iron concentrate indices obtained from Examples 1-3 and Comparative Example 1

[0107]

[0108] The comparison of data in Table 1 shows that, in the comparative example, relying solely on weak magnetic separation for iron mineral enrichment, sulfur-containing minerals such as pyrrhotite, which are weakly magnetic, are also magnetically enriched along with the iron minerals, resulting in a severely excessive sulfur content in the iron concentrate (8%), far exceeding the sulfur content required by the metallurgical industry (usually <0.5%). Simultaneously, the iron minerals are not sufficiently liberated from gangue (80% are ground to -0.045mm), and a large amount of lean intergrowth enters the magnetically separated concentrate, limiting further improvement in iron grade (only 52%). In contrast, the embodiments of this invention, through a "desulfurization before iron extraction" process design, pre-flotate to remove sulfur minerals, then combine fine grinding to fully liberate the iron minerals, and finally perform deep impurity removal through reverse flotation, increasing the iron concentrate grade to 63%~66%, reducing the sulfur content to below 0.35%, and achieving a comprehensive iron recovery rate ≥83%, thus realizing a step-by-step improvement in iron concentrate quality.

[0109] The recovery effects of associated valuable elements in Examples 1-3 and Comparative Example 1 were compared, and the results are shown in Table 2 below.

[0110] Table 2. Recovery of associated valuable elements in Examples 1-3 and Comparative Example 1

[0111]

[0112] As can be seen from the comparison of the data in Table 2, the comparative example completely disregarded the recovery of tungsten and fluorite, and the magnetic separation tailings were directly discharged into the tailings pond, resulting in a serious waste of scarce resources. In particular, the raw ore has a WO3 grade of 0.08% and a CaF2 grade of 10%, indicating significant comprehensive recovery value. However, the embodiment of this invention, by concentrating the magnetic separation tailings and employing a synergistic flotation reagent system of SZW-01 and SZY-01 combined with the Petrov process for heated refining, successfully achieved the efficient separation and recovery of fine-grained tungsten and fluorite. The tungsten concentrate grade was 58%–62% with a recovery rate of 65%–75%, and the fluorite concentrate grade was 91%–94% with a recovery rate of 68%–72%, transforming the originally discarded tailings into considerable added value.

[0113] This invention constructs a four-stage coupled process of "desulfurization-iron extraction-impurity removal-recovery," with each stage having a clearly defined function and close connection. In particular, the design of returning the reverse flotation froth (iron and gangue intergrowth) to regrinding forms an internal circulation loop, effectively avoiding the loss of iron minerals in the tailings; the design of fully reusing overflow water achieves a water saving rate of over 80%. The existing technology represented by the comparative example has three major defects: low iron concentrate grade (52%), severely excessive sulfur (8%), and complete failure to recover associated tungsten and fluorite. This invention significantly improves the quality of iron concentrate (TFe≥63%, S≤0.35%) through synergistic innovation in three aspects: grinding regime (ultrafine grinding with -0.039mm accounting for 90%~95%), process flow (desulfurization flotation → fine grinding magnetic separation → reverse flotation for impurity removal → tungsten-fluorite co-flotation → heated cleaning), and reagent system (co-collection by SZW-01 and SZY-01). It also achieves efficient comprehensive recovery of tungsten and fluorite in this type of ore (tungsten grade ≥58%, recovery rate ≥65%; fluorite grade ≥91%, recovery rate ≥68%).

Claims

1. A beneficiation method for deep separation and enrichment of valuable components in iron ore roughing concentrate, characterized in that, The process adopts a four-stage coupled technology of desulfurization-iron extraction-impurity removal-recovery. The iron concentrate is first desulfurized and then iron extracted to reduce the interference of sulfur minerals on the magnetic separation process. Then, the quality of the iron concentrate is improved in a stepwise manner by deep impurity removal through reverse flotation. The entire process includes the following steps: S1: Add water to the iron crude concentrate to make a slurry, add desulfurization flotation reagents and carry out flotation to obtain high-sulfur iron concentrate and desulfurization tailings; S2: The desulfurized tailings obtained from S1 are ground and then subjected to weak magnetic separation to obtain low-sulfur iron concentrate and magnetic separation tailings. S3: After adjusting the pH of the low-sulfur iron concentrate obtained from S2, a collector is added for reverse flotation. The froth product is returned to the grinding mill for further grinding, and the bottom product is the final iron concentrate. S4: After concentrating the magnetic separation tailings obtained in S2, add modifier, inhibitor, activator and synergist to carry out mixed flotation of tungsten and fluorite. After roughing, scavenging and cleaning, tungsten and fluorite mixed concentrate is obtained. S5: The tungsten-fluorite mixed concentrate obtained in S4 is separated by heated flotation. The flotation foam product is tungsten concentrate, and the bottom product is fluorite concentrate.

2. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In S1, the desulfurization flotation reagents include oxalic acid, copper sulfate, sodium butyl xanthate, and butylamine black, wherein the dosage of oxalic acid is 400~500 g / t, the dosage of copper sulfate is 80~120 g / t, the dosage of sodium butyl xanthate is 40~60 g / t, and the dosage of butylamine black is 8~12 g / t; the pulp concentration is 35%~40%.

3. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In step S2, the fineness of the grinding is -0.039mm, accounting for 90%~95%; the weak magnetic separation is a three-stage weak magnetic separation.

4. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In S3, the reverse flotation uses sodium carbonate to adjust the pulp pH to 8.0~8.5, and SZY-01 is used as the collector at a dosage of 50~70g / t. SZY-01 is a modified oleic acid collector, which is emulsified and prepared by emulsifying oleic acid, emulsifier, diesel oil and kerosene in a mass ratio of 70%:20%:5%:5%.

5. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In step S4, the magnetic separation tailings are concentrated to a pulp concentration of 35% to 40%.

6. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In step S4, the modifier is sodium carbonate, with a dosage of 800 g / t; the inhibitor is water glass, with a dosage of 1200 g / t; and the activator is lead nitrate, with a dosage of 400-550 g / t.

7. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In S4, the synergistic collector is a compound of SZW-01 and SZY-01, with SZW-01 dosage at 280~350g / t and SZY-01 dosage at 35~50g / t; SZW-01 is a benzohydroxyoxime acid multiligand collector.

8. The beneficiation method for deep separation and enrichment of valuable components in iron ore roughing concentrate according to claim 7, characterized in that, The hydroxamic acid group in the SZW-01 molecule has a strong complexing ability with the tungsten-oxygen active sites on the surface of tungsten minerals, and can form a stable five-membered ring chelate. The carboxylic acid group and long-chain alkane structure in the SZY-01 molecule exhibit excellent coordination adsorption and hydrophobic covering ability for calcium ions on the surface of fluorite. When combined, the two can form a composite film structure on the surface of tungsten and fluorite.

9. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In S4, the tungsten-fluorite mixed flotation process consists of one roughing, two scavenging, and three cleaning stages; the overflow water generated from the magnetic separation tailings concentration is returned to the magnetic separation and flotation operations for recycling, thus realizing the recycling of mineral processing water.

10. The beneficiation method for deep separation and enrichment of valuable components in iron ore rough and concentrate according to claim 1, characterized in that, In S5, the heated flotation adopts the Petrov process for heated and refined flotation. The flotation temperature is 90~95℃, the holding time is 0.5~1.5h, and the heated flotation reagents include NaOH, water glass and SZY-01.

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