Fine-fraction iron tailing recovery method

Abstract

The invention discloses a fine-fraction iron tailing recovery method, which relates to the technical field of iron tailing recovery, and is technically characterized by comprising the following steps: step 1, carrying out screening analysis on the granularity of iron minerals, and obtaining that the TFe grade is gradually increased along with the reduction of the granularity; 2, the total tailings are input into a vertical sand silo to be subjected to precipitation classification, bottom coarse-fraction tailings are filled, and upper overflow fine-fraction iron tailings are subjected to strong magnetic recovery; thirdly, ZH type high-intensity magnetic separation equipment is utilized, the washing water amount is set to be 0.3 MPa, the fixed magnetic field intensity is set to be 19000 Oe, the fine-fraction iron tailings in the second step are treated, and high-intensity magnetic concentrate and high-intensity magnetic tailings are obtained; fourthly, the strong magnetic concentrate obtained in the third step is screened and concentrated, the screening aperture is set to be 0.1 mm, and concentrated concentrate is obtained; and fifthly, the concentrated concentrate obtained in the fourth step is treated through a centrifugal machine, the iron ore concentrate is finally obtained, and the recovery rate of the iron ore concentrate is remarkably increased.

Description

Technical Field

[0001] The present invention relates to the technical field of iron tailings recovery, and particularly to a method for recovering fine-grained iron tailings. Background Art

[0002] Some iron ores are magnetite-mirrorite mixed iron ores, and the production process adopts a process flow of high-pressure roller grinding - large-particle wet pre-selection - stage grinding - weak magnetic separation - strong magnetic separation - spiral chute - reverse flotation. For the recovery of iron ore resources in the tailings, the capture effect of conventional pulsating high-intensity magnetic separation equipment on -0.038 mm, especially -0.019 mm fine-grained specularite, is poor, resulting in a high iron grade in the tailings, a low metal recovery rate, and a high loss of iron minerals (specularite) in the tailings, seriously affecting the economic benefits of enterprises. Therefore, in order to solve the above technical problems, the present invention provides a method for recovering fine-grained iron tailings. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a method for recovering fine-grained iron tailings, which significantly improves the recovery rate of iron concentrate.

[0004] To achieve the above object, the present invention provides the following technical solution: A method for recovering fine-grained iron tailings, comprising the following steps:

[0005] Step 1: Screen and analyze the particle size of iron minerals, and it is obtained that as the particle size becomes finer, the TFe grade gradually increases;

[0006] Step 2: Input the total tailings into a vertical sand bin for precipitation and classification, fill the bottom coarse-grained tailings, and perform high-intensity magnetic recovery on the upper overflow fine-grained iron tailings;

[0007] Step 3: Use a ZH-type high-intensity magnetic separator, set the flushing water volume to 0.3 MPa, and set the fixed magnetic field intensity to 19000 Oe to treat the iron minerals in the fine-grained iron tailings in Step 2 to obtain high-intensity magnetic concentrate and high-intensity magnetic tailings;

[0008] Step 4: Screen and concentrate the high-intensity magnetic concentrate obtained in Step 3, set the screening aperture to 0.1 mm to obtain concentrated concentrate;

[0009] Step 5: Treat the concentrated concentrate obtained in Step 4 with a centrifuge to finally obtain iron concentrate.

[0010] Compared with the prior art, the present invention provides a method for recovering fine-grained iron tailings, having the following

[0011] Advantageous Effects:

[0012] Significantly improved the recovery rate of iron concentrate, enabling greater utilization of the mined minerals, enhancing the utilization rate of mineral resources, reducing the production costs of enterprises, decreasing the emissions of heavy metals and other harmful substances in tailings, reducing environmental pollution, promoting the sustainable development of enterprises and enhancing their competitiveness.

[0013] The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it in accordance with the content of the specification, the following takes the preferred embodiments of the present invention and describes them in detail in conjunction with the drawings. The specific implementation manners of the present invention are given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0015] Figure 1 is the flow chart of the high-intensity magnetic separation test for recovering fine-grained iron from the overflow of the vertical sand bin in the present invention;

[0016] Figure 2 is the flow chart of the centrifuge test in the high-intensity magnetic concentrate - centrifuge test for recovering fine-grained iron from the overflow of the vertical sand bin in the present invention;

[0017] Figure 3 is the first flow chart of the centrifuge test in the high-intensity magnetic concentrate - screening - centrifuge test for recovering fine-grained iron from the overflow of the vertical sand bin in the present invention;

[0018] Figure 4 is the second flow chart of the centrifuge test in the high-intensity magnetic concentrate - screening - centrifuge test for recovering fine-grained iron from the overflow of the vertical sand bin in the present invention;

[0019] Figure 5 is the flow chart for recovering fine-grained iron from the overflow of the vertical sand bin in the present invention;

[0020] Figure 6 is the flow chart of the number and quality of the test for recovering fine-grained iron from the overflow of the vertical sand bin in the present invention;

[0021] Figure 7 is the final process flow in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The following combines the attached Figures 1 to 7The principles and features of the present invention are described. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. In the following paragraphs, the present invention will be described more specifically by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a very simplified form and are drawn to non-precise scales, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0023] It should be noted that when a component is referred to as "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] Now, an experiment on the recovery of fine-grained iron from the overflow of the vertical sand bin for total tailings is described.

[0026] Particle size screening analysis:

[0027]

[0028] Table 1.1 Particle size screening results of the vertical sand bin / %

[0029] From the results in Table 1.1, it can be seen that as the particle size becomes finer, the grade of TFe gradually increases. Among them, the content of the -0.074 mm particle size fraction is 79.78%, the grade of TFe is 12.30%, and the distribution rate of TFe is 92.79%; the content of the -0.030 mm particle size fraction is 53.77%, the grade of TFe is 16.05%, and the distribution rate of TFe is 81.62%;

[0030] High-intensity magnetic separation magnetic field intensity test:

[0031] Using a ZH-type high-intensity magnetic separation device, with a fixed flushing water volume of 0.1 MPa, high-intensity magnetic separation tests with different magnetic field intensities were carried out. The test flow is shown in Figure 1 , and the test results are shown in Table 1.2;

[0032]

[0033]

[0034] Table 1.2 Results of High-intensity Magnetic Separation Magnetic Field Strength Test / %

[0035] As can be seen from the results in Table 1.2, with the increase of the magnetic field strength, the yield and recovery rate of high-intensity magnetic separation concentrate gradually increase, and the grade of TFe shows a downward trend. When the magnetic field strength is 19000 Oe, the total yield of high-intensity magnetic separation concentrate is 25.61%, the grade of TFe is 28.57%, and the recovery rate of TFe is 68.67%;

[0036] High-intensity Magnetic Separation Flushing Water Volume Test:

[0037] Using the ZH type high-intensity magnetic separation equipment, with the magnetic field strength fixed at 19000 Oe, high-intensity magnetic separation tests with different flushing water volumes were carried out. The test process is the same as Figure 1 , and the test results are shown in Table 1.3;

[0038]

[0039]

[0040] Table 1.3 Results of High-intensity Magnetic Separation Flushing Water Volume Test / %

[0041] As can be seen from the results in Table 1.3, with the increase of the flushing water volume, the yield of high-intensity magnetic separation concentrate and the recovery rate of TFe gradually decrease, and the grade of TFe shows an upward trend. When the flushing water volume is 0.1 MPa, the yield of high-intensity magnetic separation concentrate is 36.37%, the grade of TFe is 30.75%, and the recovery rate of TFe is 78.17%, and the test repeatability is good; when the flushing water volume is 0.2 MPa, the yield of high-intensity magnetic separation concentrate is 33.82%, the grade of TFe is 32.10%, and the recovery rate of TFe is 77.48%. When the flushing water volume is 0.3 MPa, the yield of high-intensity magnetic separation concentrate is 31.79%, the grade of TFe is 32.79%, and the recovery rate of TFe is 72.84%;

[0042] Samples were produced under the conditions of a magnetic field strength of 19000 Oe and a flushing water volume of 0.1 MPa, and the test results are shown in Table 1.4;

[0043] Product Name Yield TFe Grade TFe Recovery Rate Strong Magnetic Concentrate 27.30 27.47 69.96 Strong Magnetic Tailings 72.70 4.43 30.04 Feed 100.00 10.72 100.00

[0044] Table 1.4 Results of Production Sample Test / %

[0045] High-intensity Magnetic Separation Concentrate - Centrifuge Test:

[0046] For the high-intensity magnetic separation concentrate produced in Table 1.4, centrifuge tests were directly carried out. The test process is shown in Figure 2 , and the test results are shown in Table 1.5;

[0047]

[0048]

[0049] Table 1.5 Centrifuge test results / %

[0050] As can be seen from the results in Table 1.5, with a fixed flushing water volume, as the centrifuge frequency increases, the concentrate yield and recovery rate increase, while the grade of TFe decreases accordingly. When the flushing water volume is 4100 ml / min and the frequency is 30 HZ, the grade of TFe in the centrifuge concentrate is 47.18%, and the operating recovery rate is 65.31%. It is difficult to obtain the expected iron concentrate (TFe grade ≥ 55%) product;

[0051] Strong magnetic concentrate - screening - centrifuge test:

[0052] (1) Screening test of strong magnetic concentrate:

[0053] The strong magnetic concentrate produced in Table 1.4 was screened, and the screening test results are shown in Table 1.6;

[0054]

[0055] Table 1.6 Screening test results of strong magnetic concentrate / %

[0056] As can be seen from the screening results in Table 1.6: The grade of TFe in the +0.074 mm particle size fraction is relatively low, with a yield of 15.68% and a TFe distribution rate of 5.46%. The yield of the -0.10 mm particle size fraction is 90.85%, the grade of TFe is 29.44%, and the TFe distribution rate is 96.80%. The yield of the -0.074 mm particle size fraction is 84.32%, the grade of TFe is 30.98%, and the TFe distribution rate is 94.54%;

[0057] The strong magnetic concentrate produced under the conditions of a magnetic field intensity of 19000 Oe and a flushing water of 0.3 MPa in Table 1.4 was screened. The screening aperture was 0.10 mm and was used for subsequent centrifuge tests with different feed grades. The screening test results are shown in Table 1.7;

[0058]

[0059] Table 1.7 Screening test results of strong magnetic concentrate / %

[0060] As can be seen from the screening results in Table 1.7: The yield of the -0.10 mm particle size fraction is 89.74%, the grade of TFe is 34.68%, and the TFe distribution rate is 96.78%. The yield of the +0.10 mm particle size fraction is 10.26%, the grade of TFe is 10.09%, and the TFe distribution rate is 3.22%;

[0061] (2) Centrifuge test

[0062] Centrifuge test one:

[0063] For the strongly magnetic concentrate produced in Table 1.4, continuous screening with a 0.1 mm aperture was carried out, and centrifuge tests were conducted on the undersize product. The test flow is shown in Figure 3 , and the test results are shown in Table 1.8;

[0064]

[0065]

[0066] Table 1.8 Centrifuge test results / %

[0067] As can be seen from the results in Table 1.8, with a fixed flushing water volume, as the centrifuge frequency increases, the concentrate yield and recovery increase, and the TFe grade decreases accordingly;

[0068] When the flushing water volume is 4600 ml / min and the frequency is 32.4 HZ, the centrifuge concentrate yield is 35.15%, the TFe grade is 55.67%, and the TFe recovery is 64.35%;

[0069] When the flushing water volume is 5100 ml / min and the frequency is 32.4 HZ, the centrifuge concentrate yield is 32.28%, the TFe grade is 56.95%, and the TFe recovery is 59.04%; when the flushing water volume is 5100 ml / min and the frequency is 37.5 HZ, the centrifuge concentrate yield is 34.98%, the TFe grade is 55.21%, and the TFe recovery is 63.91%; when the flushing water volume is 5100 ml / min and the frequency is 41.9 HZ, the centrifuge concentrate yield is 37.72%, the TFe grade is 54.99%, and the TFe recovery is 67.80%;

[0070] When the flushing water volume is 5700 ml / min and the frequency is 32.4 HZ, the centrifuge concentrate yield is 32.30%, the TFe grade is 56.65%, and the TFe recovery is 60.07%; when the flushing water volume is 5700 ml / min and the frequency is 37.5 HZ, the centrifuge concentrate yield is 34.64%, the TFe grade is 55.69%, and the TFe recovery is 63.41%; when the flushing water volume is 5700 ml / min and the frequency is 41.9 HZ, the centrifuge concentrate yield is 36.26%, the TFe grade is 55.06%, and the TFe recovery is 65.46%;

[0071] Centrifuge test two:

[0072] For the strongly magnetic concentrate produced in Table 1.4, continuous screening with a 0.1 mm aperture was carried out, and centrifuge tests were conducted on the undersize product. The centrifuge test flow is shown in Figure 4 , and the test results are shown in Table 1.9;

[0073]

[0074] Table 1.9 Centrifuge Test Results / %

[0075] As can be seen from the results in Table 1.9, with a fixed flushing water volume, as the centrifuge frequency increases, the concentrate yield and recovery rate increase, while the grade of TFe decreases accordingly. When the flushing water volume is 5700 ml / min and the frequency is 32.4 HZ, the concentrate yield of the centrifuge is 27.17%, the grade of TFe is 58.79%, and the recovery rate of TFe is 45.81%; when the flushing water volume is 5100 ml / min and the frequency is 37.5 HZ, the concentrate yield of the centrifuge is 41.04%, the grade of TFe is 56.69%, and the recovery rate of TFe is 66.40%; when the flushing water volume is 5100 ml / min and the frequency is 41.9 HZ, the concentrate yield of the centrifuge is 41.53%, the grade of TFe is 56.66%, and the recovery rate of TFe is 68.57%;

[0076] Overall process test results:

[0077] The overall process mass and quality flow is shown in Figure 5 , and the test results are shown in Table 1.10, and the mass and quality flow chart is shown in Figure 6 ;

[0078] Product Name Yield TFe Grade TFe Recovery Rate Iron Concentrate 8.30 56.66 43.16 Tailings 91.70 6.76 56.84 Feed 100.00 10.90 100.00

[0079] Table 1.10 Overall Process Results of Recovering Fine-Grained Iron from the Overflow of Vertical Sand Bins / %

[0080] As can be seen from the results in Table 1.10, by adopting the process of high-intensity magnetic separation - screening - centrifuge for the overflow of the vertical sand bin, the concentrate yield of iron concentrate that can be obtained is 8.30%, the grade of TFe is 55.66%, and the recovery rate of TFe is 43.16%.

[0081] The above is only the preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention; any ordinary technician in the industry can smoothly implement the present invention according to the instructions in the attached drawings and the above description; however, any equivalent changes such as slight modifications, decorations, and evolutions made by those skilled in the relevant art without departing from the technical solution of the present invention by using the technical content disclosed above are equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for recovering fine-grained iron tailings, characterized in that: The following steps are involved: Step 1: Screen and analyze the particle size of iron ore, and find that as the particle size becomes finer, the TFe grade gradually increases; Step 2: The total tailings are input into the vertical sand bin for sedimentation and classification, the coarse-grained tailings at the bottom are filled, and the overflow fine-grained iron tailings at the top are recovered by strong magnetic field; Step 3: Using ZH type strong magnetic separation equipment, the flushing water volume is set to 0.3MPa, and the fixed magnetic field strength is set to 19000Oe, to process the fine-grained iron tailings iron minerals in step 2 to obtain strong magnetic concentrate and strong magnetic tailings; Step 4: Screening and concentrating the strong magnetic concentrate obtained in step 3, with the screening aperture set to 0.1 mm, to obtain a concentrated concentrate; Step 5: The concentrated ore concentrate obtained in step 4 is processed by a centrifuge to finally obtain an iron ore concentrate.

Images