A beneficiation method for cooperatively recovering iron and copper from weak magnetic tailings

Abstract

This invention discloses a mineral processing method for the co-harvesting of iron and copper in weakly magnetic tailings, comprising the following steps: desliming pretreatment, copper-preferred flotation, strong magnetic tailings removal and regrinding, enhanced recovery of fine-particle iron, copper-iron separation, and iron flotation purification. Compared with conventional mineral processing methods, this invention's method for the co-harvesting of iron and copper in weakly magnetic tailings adopts a "copper first, then iron" process sequence and organically couples selective iron-copper pre-enrichment, flotation separation, high-efficiency magnetic separation, and centrifugal gravity separation technologies to construct an integrated mineral processing system. This system can improve the comprehensive utilization rate of resources, achieve efficient pre-harvesting of copper minerals, enhance the recovery effect of fine-particle iron minerals, and improve separation efficiency. It has advantages such as high iron and copper resource recovery rate and good concentrate quality, and can solve the problems of low recovery rate of fine-particle iron streams and insufficient recovery of associated copper resources in existing technologies. It has high practical value and good application prospects.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology and relates to a mineral processing method for the co-recovery of iron and copper in weak magnetic tailings. Background Technology

[0002] Currently, the main type of iron ore is a mixed ore of magnetite and hematite, accompanied by low-grade copper minerals (mainly native copper), with an average TFe grade of 43.33% and an average Cu grade of 0.101%. For this type of ore, a combined process of "stage grinding-weak magnetic separation-fine screening-washing magnetic separation-strong magnetic separation-copper flotation-regrinding-strong magnetic separation-positive flotation for iron ore separation" has shown good results in recovering magnetite. However, the following key technical issues remain regarding the treatment of tailings from weak magnetic separation: (1) Low recovery rate of fine-grained iron. Weakly magnetic tailings are rich in weakly magnetic iron minerals such as hematite and limonite, and the ore contains gangue minerals that are prone to mud formation, such as chlorite, serpentine, and calcite. These gangue minerals are prone to forming fine-grained mud when they come into contact with water during the grinding process. These muds will significantly increase the viscosity of the slurry and worsen the copper-iron separation environment. In addition, the current pulsed strong magnetic separator has limited ability to collect iron minerals of -0.038 mm, resulting in a large loss of iron metal in the strong magnetic tailings, with a distribution rate of more than 60%, which ultimately leads to a serious decrease in the recovery rate of fine-grained weakly magnetic iron minerals (mainly hematite).

[0003] (2) Insufficient recovery of associated copper resources. This is mainly reflected in the difficulty of capturing coarse-grained elemental copper and the fact that the floatability of fine-grained copper is affected by ore slime. The existing process only recovers copper from the first-stage strong magnetic concentrate flotation, and copper minerals accumulate in the process, failing to achieve early and rapid recovery. At the same time, coarse-grained native copper is difficult to capture, and the floatability of fine-grained copper is worsened by ore slime, resulting in a large amount of copper metal (such as copper distributed in the magnetic tailings, concentrated underflow and other products in various stages) not being recovered, and the overall copper recovery index is low.

[0004] (3) The process structure is not entirely reasonable. Sludge can easily interfere with subsequent flotation and magnetic separation operations, and copper minerals cannot be recovered in advance, which not only causes copper loss, but also restricts the improvement of the comprehensive iron and copper recovery index.

[0005] Therefore, there is an urgent need to develop a new beneficiation method that can efficiently and synergistically recover fine-grained iron and associated minerals from weakly magnetic tailings. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a mineral processing method for the co-recovery of iron and copper in weak magnetic tailings with high iron and copper resource recovery rate and good concentrate quality.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A mineral processing method for co-recovering iron and copper from weakly magnetic tailings includes the following steps: S1. The weak magnetic tailings are fed into a hydrocyclone for two-stage desliming in series. S2. The sand produced in step S1 is floated to recover copper minerals and obtain copper concentrate 1 and copper float I tailings. S3. Feed the copper float I tailings from step S2 into a vertical ring pulsating high-intensity magnetic separator for tailings removal to obtain a high-intensity magnetic rough concentrate, and then regrind the high-intensity magnetic rough concentrate. S4. Feed the regrinded strong magnetic coarse concentrate from step S3 into a flat-ring combined strong magnetic separator to recover fine iron minerals and obtain iron concentrate 1 and strong magnetic concentrate. S5. The strong magnetic concentrate from step S4 is subjected to flotation to obtain copper concentrate 2 and copper float II tailings. S6. Perform positive flotation on the copper II tailings from step S5 to obtain iron concentrate 2.

[0008] The above-described mineral processing method, in a further improvement, includes the following step S1: (1) The overflow of the secondary hydrocyclone generated in step S1 is subjected to gravity separation and pre-enrichment to obtain centrifugal concentrate; (2) Combine the centrifuged concentrate obtained in step (1) with the strong magnetic concentrate in step S4 for flotation.

[0009] In a further improvement to the above-mentioned mineral processing method, in step (1), a horizontal centrifugal concentrator is used to perform gravity separation and pre-enrichment of the overflow of the secondary hydrocyclone; the rotation speed of the horizontal centrifugal concentrator is 300 r / min to 800 r / min, and the water flow rate is 1 L / min to 4 L / min.

[0010] In a further improvement to the above-mentioned mineral processing method, in step S1, the iron grade of the weakly magnetic tailings is 10%–20%, the copper grade is 0.05%–0.30%, and the fineness of the material with a particle size of -0.075mm accounts for 60%–80%; the diameter of the hydrocyclone is 50 mm–100 mm, the feed pressure is 0.10 MPa–0.40 MPa, the diameter of the underflow nozzle is 5 mm–20 mm, the diameter of the overflow pipe is 20 mm–45 mm, and the cone angle is 5°–20°.

[0011] In a further improvement to the above-mentioned mineral processing method, step S2 involves flotation of the sediment using a roughing-cleaning-scavenging process; the flotation reagents used in the flotation process include a copper collector and a frother; the copper collector is CYC-20 and CYC-20A; the frother is 2... #Oil; the dosage of CYC-20 is 100 g / t to 200 g / t; the dosage of CYC-20A is 100 g / t to 200 g / t; the dosage of foaming agent is 50 g / t to 100 g / t.

[0012] In a further improvement to the above-mentioned mineral processing method, in step S3, the magnetic field strength of the vertical ring pulsating high-intensity magnetic separator is 1.0T to 1.4T; and the fineness of the regrinding (-0.075mm) is 85% to 95%.

[0013] In a further improvement to the above-mentioned mineral processing method, in step S4, the flat-ring combined high-intensity magnetic separator includes multi-stage magnetic separation discs, with the upper disc having a magnetic field strength of 0.1 T to 0.35 T, the middle disc having a magnetic field strength of 0.6 T to 1.5 T, and the lower disc having a magnetic field strength of 1.0 T to 2.0 T.

[0014] In a further improvement to the above-mentioned mineral processing method, step S5 involves flotation of the strong magnetic concentrate using a roughing-cleaning-scavenging process; the flotation reagents used in the flotation process include a copper collector and a frother; the copper collector is CYC-20 and CYC-20A; the frother is 2... # Oil; the dosage of CYC-20 is 100 g / t to 200 g / t; the dosage of CYC-20A is 100 g / t to 200 g / t; the dosage of foaming agent is 50 g / t to 100 g / t.

[0015] In a further improvement to the above-mentioned mineral processing method, in step S6, the positive flotation is a primary roughing process; the flotation reagents used in the positive flotation process include an iron collector and a frother; the iron collector is CYB; and the frother is 2... # Oil; the amount of the iron collector is 1000 g / t to 3000 g / t; the amount of the foaming agent is 50 g / t to 100 g / t.

[0016] Compared with the prior art, the advantages of the present invention are as follows: To address the problems of low recovery rate of fine-particle iron and insufficient recovery of associated copper resources in existing technologies, this invention, based on a systematic study of the mineralogical characteristics and floatability of weak magnetic tailings processes, and through a series of technological innovations and process reconfigurations, creatively proposes a beneficiation method for the co-recovery of iron and copper from weak magnetic tailings. The technical approach involved is as follows: (1.1) Process decision-making guided by process mineralogy: Through in-depth research on the intergrowth characteristics, intergrowth relationship, degree of liberation of minerals such as magnetite, pseudomorphous hematite, hematite, limonite, and native copper in weak magnetic tailings, as well as the chemical phase of copper (confirmed to be mainly native copper), the overall process principle of "copper first, then iron" was established to achieve early and fast copper recovery.

[0017] (1.2) Development of efficient pretreatment technology: By introducing a desliming-dewatering simultaneous pulping pretreatment technology based on centrifugal force field (which can reach tens of times the force of gravity), the selectivity difference between copper and iron minerals and easily mud-forming gangue minerals is effectively expanded, creating favorable conditions for subsequent efficient sorting.

[0018] (1.3) Application of advanced strong magnetic separation technology: The "combing" characteristic is adopted, namely the flat ring combined strong magnetic separator (for example, the ZH series three-stage combined strong magnetic separator). Its technical advantages are: (a) Segmented and precise separation: minerals are separated into segments according to magnetic strength and particle size range through a multi-stage magnetic separation system. They are passed through a gradient magnetic field from low to high, which greatly improves the selectivity and sufficiency of the separation process; (b) Optimized magnetic system structure: by adopting a multi-stage distribution and forming a closed magnetic circuit magnetic system design, a targeted magnetic field is generated to achieve precise capture of different magnetic minerals. The magnetic field utilization rate is maximized through the optimization of the magnetic pole structure; (c) High-performance separation medium: by using parallel sharp toothed separation medium, a magnetic induction intensity of up to 2T and 10T can be generated in the separation zone. 5 The extremely high magnetic field gradient of T / m has a strong ability to collect fine-grained weakly magnetic minerals.

[0019] (1.4) Multi-technology coupling and process synergy: Selective iron-copper pre-enrichment, flotation separation, high-efficiency magnetic separation and centrifugal gravity separation technologies are organically coupled to construct an integrated mineral processing system. Through synergistic optimization of process parameters, reagent regimes and process structure, the maximum recovery of iron and copper resources is achieved.

[0020] In particular, compared with conventional mineral processing methods, the mineral processing method for the co-harvesting of iron and copper in weakly magnetic tailings of this invention can bring the following unexpected technical effects: (2.1) High comprehensive utilization rate of resources: Through the synergistic process of "desliming-preferred copper flotation-strong magnetic tailings removal-re-grinding-centrifugal / strong magnetic combined recovery-flotation separation", the systematic and synergistic recovery of iron and copper resources in weak magnetic tailings is realized, which significantly improves the comprehensive recovery rate of the two valuable elements.

[0021] (2.2) Efficient pre-process recovery of copper minerals: Priority copper flotation is set up at the front end of the process to recover and recover fully separated medium and coarse-grained copper minerals in a timely manner, avoiding their recycling and loss in subsequent processes, and greatly improving the copper recovery rate.

[0022] (2.3) Enhanced recovery of fine-grained iron minerals: The combination of "flat ring combined strong magnetic separator" and "centrifugal concentrator" is adopted to enhance the collection and pre-enrichment of fine-grained iron minerals of different particle sizes, effectively solving the technical problem of severe loss of -0.038 mm fine-grained weak magnetic iron minerals.

[0023] (2.4) Improved sorting efficiency: By pre-desliming, the interference of ore slime on subsequent flotation and magnetic separation operations is eliminated, and the sorting environment is optimized. At the same time, through the combined cleaning process of "regrinding-weak magnetic separation-strong magnetic separation-flotation", the iron and copper minerals are fully liberated and efficiently separated, and high-quality concentrate products are obtained.

[0024] Therefore, the mineral processing method for co-recovery of iron and copper in weak magnetic tailings of the present invention has the advantages of high iron and copper resource recovery rate and good concentrate quality. It can solve the problems of low recovery rate of fine iron flow and insufficient recovery of associated copper resources in the prior art. It has high application value and good application prospects. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic diagram of the mineral processing flow for the co-recovery of iron and copper from weakly magnetic tailings in Embodiment 1 of the present invention.

[0027] Figure 2 This is a flow chart of the conventional mineral processing technology in Comparative Example 1.

[0028] Figure 3 This is a flow chart of the conventional mineral processing technology in Comparative Example 2. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0030] In the following embodiments of the present invention, unless otherwise specified, the materials and instruments used are commercially available, the equipment used is conventional equipment, and the data obtained are the average values ​​of more than three repeated experiments.

[0031] Example 1 A mineral processing method for the co-harvesting of iron and copper in weakly magnetic tailings, the process flow diagram of which is shown below. Figure 1 As shown, it includes the following steps: In this embodiment, the tailings from the weak magnetic separation of Luzhong Mining were used as feed, with a TFe grade of 17.32% and a Cu grade of 0.187%. Mineralogical studies show that the iron minerals are mainly hematite, followed by limonite, with minor amounts of magnetite and pseudomorphous hematite; the copper mineral content is low, primarily native copper and chalcopyrite, followed by bornite, with occasional chalcocite; the gangue minerals are mainly chlorite, followed by calcite, dolomite, serpentine, amphibole, and feldspar (including plagioclase and potassium feldspar), etc.

[0032] (1) The weak magnetic tailings are fed into a two-stage CZI-100 hydrocyclone for desliming pretreatment to remove the fine-grained sludge that would have an adverse effect on subsequent separation, and a secondary overflow with a yield of 71.53% (TFe and Cu grades of 17.20% and 0.22%, respectively, and TFe and Cu recovery rates of 73.01% and 85.48%, respectively) and a secondary overflow with a yield of 28.47% (TFe and Cu grades of 16.42% and 0.095%, respectively).

[0033] The CZI-100 hydrocyclone used has a diameter of 50 mm to 100 mm, a feed pressure of 0.10 MPa to 0.40 MPa, a sand discharge nozzle diameter of 5 mm to 20 mm, an overflow pipe diameter of 20 mm to 45 mm, and a cone angle of 5° to 20°.

[0034] Previous studies have shown that if only a single desliming pretreatment using a CZI-100 hydrocyclone is employed, the overflow from the hydrocyclone stage will contain a certain amount of medium to coarse particles due to the limited classification efficiency. This will affect the subsequent recovery effect of a centrifugal concentrator under narrow particle size conditions. Furthermore, if a three-stage desliming process is adopted, it cannot be implemented due to the low concentration of the second stage slime, which would also complicate the process and increase input costs.

[0035] (2) The secondary overflow from step (1) is fed into a centrifugal concentrator for gravity separation and pre-enrichment (rotation speed is 600 r / min, water flow is 2.2 L / min); centrifugal concentrate with a yield of 4.32% is obtained (TFe and Cu grades are 43.66% and 0.12%, respectively, and TFe and Cu recovery rates are 10.89% and 2.69%, respectively).

[0036] (3) The sediment from step (2) is subjected to flotation to prioritize the recovery of copper minerals. The flotation process consists of one roughing, one cleaning, and one scavenging step. The reagent regime is as follows: 50 g / t of collector CYC-20 and 50 g / t of collector CYC-20A are added to the roughing step. # Oil 60 g / t; Selective processing with added collector CYC-20 10 g / t, collector CYC-20A 10 g / t; Scavenging with added collector CYC-20 25 g / t, collector CYC-20A 25 g / t, 2 # Oil yield 30 g / t. A copper concentrate 1 with a yield of 0.66% (Cu grade 17.26%, Cu recovery rate 60.92%) and copper tailings I were obtained.

[0037] In this flotation step, the tailings generated during the copper beneficiation process and the froth products generated during the copper scavenging process are returned to the copper roughing process.

[0038] (4) The copper tailings from step (3) are fed into a vertical ring pulsating strong magnetic separator (magnetic field strength is 1.2T) to obtain a strong magnetic rough concentrate with a yield of 23.56% (TFe and Cu grades are 40.87% and 0.11%, respectively, and TFe and Cu recovery rates are 55.59% and 13.86%, respectively). The strong magnetic concentrate is then regrinded and dissociated, and the regrinding fineness is 89.38% to -0.075mm.

[0039] (5) The regrinded strong magnetic coarse concentrate from step (4) is subjected to a flat-ring combined strong magnetic separator to enhance the recovery of fine iron minerals. The flat-ring combined separator has a magnetic field strength of 0.18T on the upper plate, 1.1T on the middle plate, and 1.6T on the lower plate. Iron concentrate 1 with an upper plate yield of 3.65% (TFe grade of 60.10% and TFe recovery rate of 12.67%) and strong magnetic concentrate with a middle and lower plate yield of 12.62% (TFe grade of 47.32% and TFe recovery rate of 34.48%) can be obtained.

[0040] (6) Combine the centrifuged concentrate from step (2) and the strong magnetic concentrate from step (5) for copper flotation 2. The flotation process is one rougher, one cleaner, and one scavenger. The reagent regime is as follows: for roughing, add collector CYC-20 50g / t, collector CYC-20A 50g / t, and 2 # Oil 60g / t; Selective processing adds collector CYC-20 10g / t, collector CYC-20A 10g / t; Scavenging adds collector CYC-20 25g / t, collector CYC-20A 25g / t, 2 # Oil 30 g / t. Yield of copper concentrate 2 and copper tailings II with a yield of 0.10% (Cu grade 15.24%, Cu recovery rate 8.15%).

[0041] In this flotation step, the tailings generated during the copper beneficiation process and the froth products generated during the copper scavenging process are returned to the copper roughing process.

[0042] (7) The copper tailings from step (6) are subjected to positive flotation, specifically, a roughing process is performed by adding collector CYB 2000g / t and 2 # 60g / t of oil was used to obtain 2 iron concentrates with a yield of 11.24% (TFe grade of 58.70% and TFe recovery rate of 38.09%).

[0043] The final technical specifications in this embodiment are shown in Table 1: the total copper concentrate yield is 0.76%, the Cu grade is 16.99%, and the Cu recovery rate is 69.07%; the total iron concentrate yield is 14.89%, the TFe grade is 59.04%, and the TFe recovery rate is 50.76%.

[0044] Table 1 Technical Indicators for Copper and Iron Recovery Process in Weakly Magnetic Tailings (%)

[0045] Comparative Example 1: A beneficiation method for weakly magnetic tailings, such as Figure 2 As shown, it includes the following steps: The same feed as in Example 1 was used, meaning the ore properties were identical. The comparative beneficiation process was: feed - strong magnetic flotation - copper flotation - regrinding - weak magnetic flotation - strong magnetic flotation - positive flotation for iron. The beneficiation flow chart is shown below. Figure 2 The specific ore beneficiation steps are as follows: (1) The weak magnetic tailings are fed into the vertical ring strong magnetic separator, and the magnetic field strength is 1.0T to obtain strong magnetic rough concentrate and strong magnetic tailings.

[0046] (2) Strong magnetic rough concentrate feeding copper flotation operation. The flotation process consists of one roughing, one cleaning, and one scavenging stage. The reagent regime is as follows: CYC-20 collector 100g / t is added to the roughing stage. # Oil 30 g / t; Selective processing with added collector CYC-20 10 g / t; Scavenging processing with added collector CYC-20 50 g / t, 2 # Oil yield 15 g / t. A copper concentrate with a yield of 0.49% (Cu grade 17.41%, Cu recovery rate 45.62%) and copper tailings were obtained.

[0047] (3) The copper tailings were regrinded and re-selected. The regrinding fineness of -0.075mm was 91.40%. After regrinding, magnetite was recovered by weak magnetic field with a magnetic field strength of 0.20T. The weak magnetic iron concentrate 1 and weak magnetic tailings were obtained with a yield of 3.88% (TFe grade of 56.02% and TFe recovery rate of 12.55%).

[0048] (4) The tailings from the weak magnetic separation are subjected to vertical ring strong magnetic separation with a magnetic field strength of 0.8T to obtain strong magnetic concentrate.

[0049] (5) The strong magnetic concentrate is subjected to positive flotation, roughing in one stage, and activator CYZ-40 2000g / t and collector CY-22 1000g / t are added to obtain iron concentrate 2 with a yield of 11.21% (TFe grade of 49.47% and TFe recovery rate of 32.02%).

[0050] The final technical specifications in this comparative example are shown in Table 2: the copper concentrate yield is 0.49%, the Cu grade is 17.41%, and the Cu recovery rate is 45.62%; the total iron concentrate yield is 15.09%, the TFe grade is 51.15%, and the TFe recovery rate is 44.57%.

[0051] Table 2 Comparative Technical Indicators for Copper and Iron Recovery Processes in Weakly Magnetic Tailings (%)

[0052] Example 2: A mineral processing method for the co-harvesting of iron and copper in weakly magnetic tailings, the process flow diagram of which is shown below. Figure 1 As shown, it includes the following steps: In this embodiment, the tailings from the weak magnetic separation of Luzhong Mining were used as feed, further depleting the ore to a TFe grade of 13.19% and a Cu grade of 0.13%. Process mineralogical studies show that the iron minerals are mainly hematite, followed by limonite, with minor amounts of magnetite and pseudomorphous hematite; the copper mineral content is low, mainly native copper and chalcopyrite, followed by bornite, with occasional chalcocite; the gangue minerals are mainly chlorite and serpentine, followed by dolomite, calcite, amphibole, and feldspar (including plagioclase and potassium feldspar), etc.

[0053] like Figure 1 As shown, the specific ore beneficiation steps are as follows: (1) The weak magnetic tailings are fed into a two-stage CZI-100 hydrocyclone for desliming pretreatment to remove the fine-grained sludge that would have an adverse effect on subsequent separation, and a secondary overflow with a yield of 73.35% (TFe and Cu grades of 13.34% and 0.15%, respectively, with TFe and Cu recovery rates of 74.17% and 81.08%, respectively) and a secondary overflow with a yield of 26.65% (TFe and Cu grades of 12.78% and 0.094%, respectively).

[0054] The CZI-100 hydrocyclone used has a diameter of 50 mm to 100 mm, a feed pressure of 0.10 MPa to 0.40 MPa, a sand discharge nozzle diameter of 5 mm to 20 mm, an overflow pipe diameter of 20 mm to 45 mm, and a cone angle of 5° to 20°.

[0055] (2) The secondary overflow from step (1) is fed into a centrifugal concentrator for gravity separation and pre-enrichment (rotation speed is 600 r / min, water flow is 2.2 L / min); centrifugal concentrate with a yield of 2.47% is obtained (TFe and Cu grades are 39.36% and 0.12%, respectively, and TFe and Cu recovery rates are 7.37% and 2.19%, respectively).

[0056] (3) The sediment from step (2) is subjected to flotation to preferentially recover copper minerals. The flotation process consists of one roughing, one cleaning, and one scavenging step. The reagent regime is as follows: 50 g / t of collector CYC-20 and 50 g / t of collector CYC-20A are added to the roughing step. # Oil 60 g / t; Selective processing with added collector CYC-20 10 g / t, collector CYC-20A 10 g / t; Scavenging with added collector CYC-20 25 g / t, collector CYC-20A 25 g / t, 2 #Oil yield 30 g / t. A copper concentrate 1 with a yield of 0.51% (Cu grade 14.83%, Cu recovery rate 56.87%) and copper tailings I were obtained.

[0057] (4) The copper tailings from step (3) are fed into a vertical ring pulsating strong magnetic separator (magnetic field strength of 1.2T) to obtain a strong magnetic rough concentrate with a yield of 22.03% (TFe and Cu grades of 31.86% and 0.062%, respectively, and TFe and Cu recovery rates of 53.21% and 10.28%, respectively). The strong magnetic concentrate is then regrinded and dissociated, and the regrinding fineness of -0.075mm is 90.59%.

[0058] (5) The regrinded strong magnetic coarse concentrate from step (4) is subjected to a flat-ring combined strong magnetic separator (commercially available) to enhance the recovery of fine iron minerals. The flat-ring combined separator has a magnetic field strength of 0.18T on the upper plate, 1.1T on the middle plate, and 1.6T on the lower plate. This can yield an iron concentrate with a yield of 2.71% (TFe grade of 64.20% and TFe recovery rate of 13.19%) and a strong magnetic concentrate with a yield of 12.09% (TFe grade of 39.81% and TFe recovery rate of 36.49%).

[0059] (6) Combine the centrifuged concentrate from step (2) and the strong magnetic concentrate from step (5) for copper flotation 2. The flotation process consists of one roughing, one cleaning, and one scavenging step. The reagent regime is as follows: 50g / t of collector CYC-20 and 50g / t of collector CYC-20A are added to the roughing process. # Oil 60g / t; Selective processing adds collector CYC-20 10g / t, collector CYC-20A 10g / t; Scavenging adds collector CYC-20 25g / t, collector CYC-20A 25g / t, 2 # The oil yielded 30 g / t, producing copper concentrate 2 and copper tailings II with a yield of 0.06% (Cu grade 14.25%, Cu recovery rate 6.43%).

[0060] (7) Perform positive flotation to remove iron from the copper II tailings obtained in step (6) (first roughing, adding collector CYB 2000g / t, 2 # 60g / t of oil); 2 iron concentrates with a yield of 9.14% (TFe grade of 52.57% and TFe recovery rate of 36.43%).

[0061] The final technical specifications in this embodiment are shown in Table 3: the total copper concentrate yield is 0.57%, the Cu grade is 14.77%, and the Cu recovery rate is 63.30%; the total iron concentrate yield is 11.85%, the TFe grade is 55.23%, and the TFe recovery rate is 49.62%.

[0062] Table 3 Technical Indicators for Copper and Iron Recovery Process in Weakly Magnetic Tailings (%)

[0063] Comparative Example 2: A beneficiation method for weakly magnetic tailings, such as Figure 3 As shown, it includes the following steps: This comparative example uses the same feed as Example 2, meaning the ore properties are consistent with Example 2. The beneficiation process for the comparative example is: feed - strong magnetic flux - copper flotation - regrinding - weak magnetic flux - strong magnetic flux - copper flotation. The beneficiation flow chart is shown below. Figure 3 The specific ore beneficiation steps are as follows: (1) The weak magnetic tailings are fed into a vertical ring pulsating strong magnetic separator with a magnetic field strength of 1.0T to obtain strong magnetic rough concentrate and strong magnetic tailings.

[0064] (2) Copper flotation of strong magnetic rough concentrate 1. The flotation process is roughing-cleaning-scavenging, and the reagent regime is as follows: CYC-20 collector 100g / t is added to the roughing stage. # Oil 30 g / t; Selected oil with added collector CYC-20 10 g / t; Scavenged oil with added collector CYC-20 50 g / t, 2 g / t # Oil yield 15 g / t. A copper concentrate 1 with a yield of 0.38% (Cu grade 14.85%, Cu recovery rate 42.43%) and copper tailings were obtained.

[0065] (3) The copper tailings were regrinded and re-selected. The regrinding fineness of -0.075mm was 90.34%. After regrinding, magnetite was recovered by weak magnetic field with a magnetic field strength of 0.20T. The yield of weak magnetic iron concentrate 1 and weak magnetic tailings was 2.82% (TFe grade was 62.66% and TFe recovery rate was 13.40%).

[0066] (4) The tailings of the weak magnetic separation are subjected to vertical ring pulsating strong magnetic separation with a magnetic field strength of 0.8T to obtain strong magnetic concentrate.

[0067] (5) Copper flotation of strong magnetic concentrate 2. The flotation process is roughing, cleaning and scavenging, and the reagent system is as follows: 100g / t collector CYC-20 is added to the roughing stage. # Oil 30 g / t; Selected oil with added collector CYC-20 10 g / t; Scavenged oil with added collector CYC-20 50 g / t, 2 g / t # Oil 15 g / t. Obtained 0.05% copper concentrate 2 (Cu grade 11.73%, Cu recovery rate 14.49%) and 7.55% iron concentrate 2 (floating copper tailings) (TFe grade 47.93%, TFe recovery rate 27.44%).

[0068] The final technical specifications in this comparative example are shown in Table 4: the copper concentrate yield is 0.43%, the Cu grade is 14.49%, and the Cu recovery rate is 46.84%; the total iron concentrate yield is 10.37%, the TFe grade is 51.94%, and the TFe recovery rate is 40.83%.

[0069] Table 4 Comparative Technical Indicators for Copper and Iron Recovery Processes in Weakly Magnetic Tailings (%)

[0070] The results above show that, compared with conventional mineral processing methods, the mineral processing method for the co-harvesting of iron and copper in weakly magnetic tailings of this invention can bring the following unexpected technical effects: (2.1) High comprehensive utilization rate of resources: Through the synergistic process of "desliming-preferred copper flotation-strong magnetic tailings removal-re-grinding-centrifugal / strong magnetic combined recovery-flotation separation", the systematic and synergistic recovery of iron and copper resources in weak magnetic tailings is realized, which significantly improves the comprehensive recovery rate of the two valuable elements.

[0071] (2.2) Efficient pre-process recovery of copper minerals: Priority copper flotation is set up at the front end of the process to recover and recover fully separated medium and coarse-grained copper minerals in a timely manner, avoiding their recycling and loss in subsequent processes, and greatly improving the copper recovery rate.

[0072] (2.3) Enhanced recovery of fine-grained iron minerals: The combination of "flat ring combined strong magnetic separator" and "centrifugal concentrator" is adopted to enhance the collection and pre-enrichment of fine-grained iron minerals of different particle sizes, effectively solving the technical problem of severe loss of -0.038 mm fine-grained weak magnetic iron minerals.

[0073] (2.4) Improved sorting efficiency: By pre-desliming, the interference of ore slime on subsequent flotation and magnetic separation operations is eliminated, and the sorting environment is optimized. At the same time, through the combined cleaning process of "regrinding-weak magnetic separation-strong magnetic separation-flotation", the iron and copper minerals are fully liberated and efficiently separated, and high-quality concentrate products are obtained.

[0074] Therefore, the mineral processing method for co-recovery of iron and copper in weak magnetic tailings of the present invention has the advantages of high iron and copper resource recovery rate and good concentrate quality. It can solve the problems of low recovery rate of fine iron flow and insufficient recovery of associated copper resources in the prior art. It has high application value and good application prospects.

[0075] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A mineral processing method for the co-harvesting of iron and copper in weakly magnetic tailings, characterized in that, Includes the following steps: S1. The weak magnetic tailings are fed into a hydrocyclone for two-stage desliming in series. S2. The sand produced in step S1 is floated to recover copper minerals and obtain copper concentrate 1 and copper float I tailings. S3. Feed the copper float I tailings from step S2 into a vertical ring pulsating high-intensity magnetic separator for tailings removal to obtain a high-intensity magnetic rough concentrate, and then regrind the high-intensity magnetic rough concentrate. S4. Feed the regrinded strong magnetic coarse concentrate from step S3 into a flat-ring combined strong magnetic separator to recover fine iron minerals and obtain iron concentrate 1 and strong magnetic concentrate. S5. The strong magnetic concentrate from step S4 is subjected to flotation to obtain copper concentrate 2 and copper float II tailings. S6. Perform positive flotation on the copper II tailings from step S5 to recover iron minerals and obtain iron concentrate 2.

2. The mineral processing method according to claim 1, characterized in that, Step S1 also includes the following processing: (1) The overflow of the secondary hydrocyclone generated in step S1 is subjected to gravity separation and pre-enrichment to obtain centrifugal concentrate; (2) Combine the centrifuged concentrate obtained in step (1) with the strong magnetic concentrate in step S4 for flotation.

3. The mineral processing method according to claim 2, characterized in that, In step (1), a horizontal centrifugal concentrator is used to perform gravity separation and pre-enrichment of the overflow from the secondary hydrocyclone; the rotation speed of the horizontal centrifugal concentrator is 300 r / min to 800 r / min, and the water flow rate is 1 L / min to 4 L / min.

4. The mineral processing method according to any one of claims 1 to 3, characterized in that, In step S1, the weak magnetic tailings have an iron grade of 10%–20%, a copper grade of 0.05%–0.30%, and a fineness of -0.075mm grade accounting for 60%–80%; the hydrocyclone has a diameter of 50 mm–100 mm, a feed pressure of 0.10 MPa–0.40 MPa, a sand discharge nozzle diameter of 5 mm–20 mm, an overflow pipe diameter of 20 mm–45 mm, and a cone angle of 5°–20°.

5. The mineral processing method according to any one of claims 1 to 3, characterized in that, In step S2, the sediment is flotated using a coarse-fine-scavenging process; the flotation reagents used in the flotation process include a copper collector and a frother; the copper collector is CYC-20 and CYC-20A; the frother is 2... # Oil; the dosage of CYC-20 is 100 g / t to 200 g / t; the dosage of CYC-20A is 100 g / t to 200 g / t; the dosage of foaming agent is 50 g / t to 100 g / t.

6. The mineral processing method according to any one of claims 1 to 3, characterized in that, In step S3, the magnetic field strength of the vertical ring pulsating high-intensity magnetic separator is 1.0T to 1.4T; the fineness of the regrinding (-0.075mm) is 85% to 95%.

7. The mineral processing method according to any one of claims 1 to 3, characterized in that, In step S4, the flat-ring combined high-intensity magnetic separator includes multiple magnetic separation disks, with the upper disk having a magnetic field strength of 0.1 T to 0.35 T, the middle disk having a magnetic field strength of 0.6 T to 1.5 T, and the lower disk having a magnetic field strength of 1.0 T to 2.0 T.

8. The mineral processing method according to any one of claims 1 to 3, characterized in that, In step S5, the strong magnetic concentrate is flotated using a roughing-cleaning-scavenging method; the flotation reagents used in the flotation process include a copper collector and a frother; the copper collector is CYC-20 and CYC-20A; the frother is 2... # Oil; the dosage of CYC-20 is 100 g / t to 200 g / t; the dosage of CYC-20A is 100 g / t to 200 g / t; the dosage of foaming agent is 50 g / t to 100 g / t.

9. The mineral processing method according to any one of claims 1 to 3, characterized in that, In step S6, the positive flotation is a primary roughing process; the flotation reagents used in the positive flotation process include an iron collector and a frother; the iron collector is CYB; the frother is 2... # Oil; the amount of the iron collector is 1000 g / t to 3000 g / t; the amount of the foaming agent is 50 g / t to 100 g / t.

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