Mine solid waste rare earth element carrier ore fluidization separation and enrichment method

Abstract

The invention belongs to the technical field of rare earth element separation, and particularly relates to a fluidization, separation and enrichment method for rare earth element carrier ore of mine solid waste. Comprising the following steps that a mixture of pulverized coal and ferrosilicon powder serves as a separation medium and is added into a vibration gas-solid separation fluidized bed device, and the vibration frequency, the amplitude parameter and the gas speed of pulse airflow of the vibration gas-solid separation fluidized bed device are set according to the density of mine solid waste rare earth element carrier minerals, the separation granularity and the content of rare earth elements; the mine solid waste rare earth element carrier minerals form a scattered fluidization environment with uniform and stable density under the vibration-airflow synergistic effect of the vibration gas-solid separation fluidized bed, density gradient layering is carried out, and separation and pre-enrichment of rare earth elements in the mine solid waste rare earth element carrier minerals are achieved. According to the method, high-density coal gangue containing high rare earth elements is efficiently and accurately sorted, and the problem of pre-enrichment of the rare earth elements in mine solid waste rare earth element carrier minerals is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of rare earth element separation technology, specifically relating to a fluidized bed separation and enrichment method for rare earth element carrier minerals in mine solid waste. Background Technology

[0002] Rare earth elements, as key metals, play an irreplaceable role in various fields such as electronics, energy, aerospace, and military industry. However, with the large-scale mining of rare earth resources, high-grade rare earth deposits are becoming increasingly scarce, and my country's share of global rare earth reserves is declining year by year. Therefore, recovering rare earth elements from non-traditional resources is of great significance for expanding my country's rare earth resource reserves and ensuring the strategic security of my country's rare earth resources. Coal gangue, as one of the largest sources of mining solid waste in my country, occupies a large amount of land resources, and the dust and harmful gases it produces endanger human health and put enormous pressure on the ecological environment. Currently, the treatment of coal gangue in my country is mainly concentrated in large-scale utilization technologies such as cement production, tunnel filling, and coal gangue power generation, with a low utilization rate of high-value-added coal gangue. Coal gangue is rich in rare earth elements such as lanthanum, cerium, and neodymium, and my country is a major coal resource country, with the rare earth element content in coal gangue higher than the average level in the United States, giving China a unique advantage in extracting rare earth elements from coal gangue. Therefore, a large amount of coal gangue is generated during coal mining and processing. Coal gangue often contains rare earth elements. Therefore, the pre-enrichment and separation of coal gangue containing rare earth elements is of great significance for the recovery and utilization of rare earth elements and the large-scale resource utilization of coal gangue.

[0003] Efficient and low-cost physical separation and enrichment is a prerequisite for the large-scale resource utilization of coal gangue, directly affecting the leaching and upgrading efficiency, energy consumption, and product grade of rare earth elements in coal gangue. Traditional physical separation methods for rare earth elements include density separation, particle size separation, magnetic separation, electrostatic separation, and flotation. Among these, density separation can maximize the separation and enrichment of rare earth minerals, achieving the goal of recovering rare earth elements. However, since rare earth elements are mainly found in high-density coal gangue, and current traditional gas-solid fluidized bed separators have a lower upper limit for separation density than high-density coal gangue, resulting in lower separation particle size. Therefore, they cannot efficiently and accurately separate high-density coal gangue. Furthermore, traditional gas-solid fluidized bed separators suffer from poor fluidization effects, leading to low separation accuracy for coal gangue. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a fluidized bed separation and enrichment method for rare earth element carrier minerals in mine solid waste. This method efficiently and accurately separates high-density coal gangue containing high levels of rare earth elements, effectively solving the problem of rare earth element pre-enrichment in coal gangue. It provides an effective separation method for the large-scale resource utilization of coal gangue and the pre-enrichment of rare earth elements in coal-based solid waste—coal gangue. Furthermore, it provides a gas-solid fluidized bed separation method for high-density materials. This method is low-cost, simple to operate, accurate, and efficient, with general applicability. By adjusting the mixing ratio of the medium, it can be applied to the efficient and accurate separation of various high-density materials.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0006] The purpose of this invention is to provide a method for fluidized bed separation and enrichment of rare earth element carrier minerals in mine solid waste, comprising the following steps:

[0007] A mixture of pulverized coal and ferrosilicon powder is used as the separation medium and added to a vibrating gas-solid separation fluidized bed device. The vibration frequency, amplitude parameters, and pulse air velocity of the vibrating gas-solid separation fluidized bed device are set according to the density, separation particle size, and rare earth element content of the rare earth element carrier minerals in the mine solid waste. Under the synergistic effect of vibration and airflow in the vibrating gas-solid separation fluidized bed, the rare earth element carrier minerals in the mine solid waste form a uniform and stable dispersed fluidized environment, and density gradient stratification is carried out to achieve the separation and pre-enrichment of rare earth elements in the rare earth element carrier minerals in the mine solid waste.

[0008] Furthermore, the density of the rare earth element carrier minerals in the mine solid waste is ≥2.0 g / cm³. 3 .

[0009] Furthermore, the mass ratio of pulverized coal to ferrosilicon powder is 1:4 to 9.

[0010] Furthermore, the pulverized coal is Geldart A type pulverized coal with a particle size of 45µm to 74µm and a density of 1.2g / cm³. 3 ~1.8g / cm 3 The ferrosilicon powder is Geldart B type ferrosilicon powder with a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm³. 3 ~7.07g / cm 3

[0011] Furthermore, the vibration frequency is 10Hz to 50Hz, the amplitude is 1mm to 5mm, and the gas flow rate is 30cm / s to 50cm / s.

[0012] Furthermore, the vibrating gas-solid separation fluidized bed device includes a separation and enrichment fluidized bed, with multiple pressure sensors equidistantly installed along the body axis of the separation and enrichment fluidized bed. A vibration table is provided below the separation and enrichment fluidized bed, and a dust removal device is provided above it. All pressure sensors and the vibration table are connected to a control system. The pressure drop fluctuations within the vibrating gas-solid separation fluidized bed are monitored by all pressure sensors, and the signals are transmitted to the control system. The control system monitors and adjusts the density fluctuations of the vibration table and the fluidization state of the bed in real time.

[0013] Furthermore, the vibration table is equipped with a pulsed airflow pipe and a constant airflow pipe. The outlets of both the pulsed airflow pipe and the constant airflow pipe are located directly below the enriched fluidized bed. The pulsed airflow pipe is equipped with a first flow meter, a first valve, and a butterfly valve, while the constant airflow pipe is equipped with a second flow meter and a second valve.

[0014] Furthermore, the first flow meter, the first valve, the second flow meter, and the second valve are all connected to the control system via signals.

[0015] Furthermore, the rare earth element carrier mineral in mine solid waste is coal gangue.

[0016] Furthermore, after the pre-enrichment of the separation is completed, the lower layer of the vibrating gas-solid separation fluidized bed contains rare earth elements.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] This invention uses a mixture of pulverized coal and ferrosilicon powder as the separation medium, which is added to a vibrating gas-solid separation fluidized bed device. The vibration frequency, amplitude parameters, and pulse airflow velocity of the vibrating gas-solid separation fluidized bed device are set according to the density, separation particle size, and rare earth element content of the rare earth element carrier minerals in the mine solid waste. Under the synergistic effect of vibration and airflow, the pulverized coal and ferrosilicon powder mixture separation medium bed forms a separation suspension environment. The rare earth element carrier minerals in the mine solid waste, under the synergistic effect of vibration and airflow in the solid separation fluidized bed, and the separation medium... In a suspended environment, the movement activity of rare earth element carrier mineral particles in the mine solid waste is enhanced, which strengthens the breaking down of material accumulation and forms a uniform and stable dispersed fluidized environment. This achieves uniform fluidization of materials, and coal gangue rich in rare earth carrier minerals is sorted according to the fixed density of the bed. High-density particles with a density greater than the bed density sink as rare earth element carrier mineral products, while minerals with a density less than the bed density float to the surface as tailings and are discharged. This enables large-scale and precise sorting and pre-enrichment of rare earth elements in rare earth element carrier minerals in mine solid waste. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the vibrating gas-solid separation fluidized bed device of the present invention.

[0020] Figure 2 This is a schematic diagram of the sorting and enrichment process of the present invention.

[0021] Illustration:

[0022] 1. Sorting and enriching fluidized bed; 2. Pressure sensor; 3. Vibrating table; 4. Dust removal device; 5. Control system; 6. Pulse airflow pipe; 61. First flow meter; 62. First valve; 63. Butterfly valve; 7. Constant airflow pipe; 71. Second flow meter; 72. Second valve. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0025] Since rare earth elements are mainly found in high-density coal gangue, traditional gas-solid fluidized bed separators currently have a lower upper limit for separation density than high-density coal gangue, resulting in a lower separation particle size. Therefore, they cannot efficiently and accurately separate high-density coal gangue. Furthermore, traditional gas-solid fluidized bed separators have drawbacks such as poor fluidization effect and low separation accuracy for coal gangue.

[0026] To address the aforementioned problems, this invention provides a method for fluidized bed separation and enrichment of rare earth element carrier minerals in mine solid waste, such as... Figure 2 As shown, it includes the following steps:

[0027] A mixture of pulverized coal and ferrosilicon powder is used as the separation medium and added to a vibrating gas-solid separation fluidized bed device. The vibration frequency, amplitude parameters, and pulse air velocity of the vibrating gas-solid separation fluidized bed device are set according to the density, separation particle size, and rare earth element content of the rare earth element carrier minerals in the mine solid waste. Under the synergistic effect of vibration and airflow in the vibrating gas-solid separation fluidized bed, the rare earth element carrier minerals in the mine solid waste form a uniform and stable dispersed fluidized environment, and density gradient stratification is carried out to achieve the separation and pre-enrichment of rare earth elements in the rare earth element carrier minerals in the mine solid waste.

[0028] This invention uses a mixture of pulverized coal and ferrosilicon powder as the separation medium, which is added to a vibrating gas-solid separation fluidized bed device. The vibration frequency, amplitude parameters, and pulse airflow velocity of the vibrating gas-solid separation fluidized bed device are set according to the density, separation particle size, and rare earth element content of the rare earth element carrier minerals in the mine solid waste. Under the synergistic effect of vibration and airflow, the pulverized coal and ferrosilicon powder mixture separation medium bed forms a separation suspension environment. The rare earth element carrier minerals in the mine solid waste, under the synergistic effect of vibration and airflow in the solid separation fluidized bed, and the separation medium... In a suspended environment, the movement activity of rare earth element carrier mineral particles in the mine solid waste is enhanced, which strengthens the breaking down of material accumulation and forms a uniform and stable dispersed fluidized environment. This achieves uniform fluidization of materials, and coal gangue rich in rare earth carrier minerals is sorted according to the fixed density of the bed. High-density particles with a density greater than the bed density sink as rare earth element carrier mineral products, while minerals with a density less than the bed density float to the surface as tailings and are discharged. This enables large-scale and precise sorting and pre-enrichment of rare earth elements in rare earth element carrier minerals in mine solid waste.

[0029] In one specific embodiment, the density of the rare earth element carrier mineral in the mine solid waste is ≥2.0 g / cm³. 3 It should be noted that rare earth elements are mainly found in high-density coal gangue, while traditional gas-solid fluidized bed separation methods have low separation density and high lower limit for particle size distribution, making them suitable for coal gangue (≥2.0 g / cm³). 3 It is impossible to separate rare earth element carrier minerals according to density in the bed.

[0030] In one specific embodiment, the mass ratio of pulverized coal to ferrosilicon powder is 1:4 to 9. The pulverized coal is Geldart A type pulverized coal with a particle size of 45 μm to 74 μm and a density of 1.2 g / cm³. 3 ~1.8g / cm 3 The ferrosilicon powder is Geldart B type ferrosilicon powder with a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm³. 3 ~7.07g / cm 3 This invention uses Geldart A-type coal powder (45µm~74µm, 1.2g / cm³). 3 ~1.8g / cm 3 ) and Geldart B-type ferrosilicon powder (0.074mm~0.4mm, 6.55g / cm) 3 ~7.07g / cm 3 The mixture forms a uniform and stable dispersed fluidized environment under the synergistic excitation of vibration and airflow, which efficiently separates and enriches rare earth element carrier minerals in coal gangue.

[0031] In one specific embodiment, the vibration frequency is 10Hz to 50Hz, the amplitude is 1mm to 5mm, and the gas flow rate is adjusted to 30cm / s to 50cm / s. Figure 2 As shown, this invention utilizes a gas-solid separation fluidized bed where vibration and airflow work together to enhance the movement of gangue particles within the bed, thereby strengthening the material's accumulation and forming a better fluidized bed. This achieves uniform fluidization of the material, allowing it to stratify according to a density gradient. Low-density materials are distributed in the upper layer, while high-density coal gangue products containing relatively high-grade rare earth elements are enriched in the lower layer, achieving the effect of pre-enriching rare earth elements in coal gangue.

[0032] In a specific embodiment, such as Figure 1 As shown, the vibrating gas-solid separation fluidized bed device includes a separation and enrichment fluidized bed 1. Multiple pressure sensors 2 are equidistantly installed along the axial direction of the separation and enrichment fluidized bed 1. A vibration table 3 is located below the separation and enrichment fluidized bed 1, and a dust removal device 4 is located above it. All pressure sensors 2 and the vibration table 3 are signal-connected to a control system 5. The pressure drop fluctuations within the vibrating gas-solid separation fluidized bed are monitored by all pressure sensors 2, and the signals are transmitted to the control system 5. The control system 5 monitors and regulates the density fluctuations and fluidization state of the vibrating gas-solid separation fluidized bed 1 in real time. The separation and enrichment fluidized bed 1 is a cylindrical organic glass container with an inner diameter of 200 mm and a height of 400 mm. An air distribution plate is provided on the lower bottom wall of the separation and enrichment fluidized bed 1, with an opening ratio of 20% to 25%.

[0033] In one specific embodiment, the vibration table 3 is provided with a pulsed airflow pipe 6 and a constant airflow pipe 7. The outlets of both the pulsed airflow pipe 6 and the constant airflow pipe 7 are located directly below the enriched fluidized bed 1. The pulsed airflow pipe 6 is provided with a first flow meter 61, a first valve 62 and a butterfly valve 63, and the constant airflow pipe 7 is provided with a second flow meter 71 and a second valve 72.

[0034] In one specific embodiment, the first flow meter 61, the first valve 62, the second flow meter 71, and the second valve 72 are all signal-connected to the control system 5.

[0035] In one specific embodiment, the rare earth element carrier mineral in mine solid waste is coal gangue.

[0036] In one specific embodiment, after the pre-enrichment is completed, the lower layer of the vibrating gas-solid separation fluidized bed contains rare earth elements. This invention, through the synergistic effect of vibration and airflow, causes the material to stratify according to a density gradient, with low-density material distributed in the upper layer and high-density coal gangue containing relatively high-grade rare earth elements enriched in the lower layer, achieving the effect of rare earth element pre-enrichment in coal gangue.

[0037] The following specific examples will provide further explanation.

[0038] Example

[0039] This embodiment discloses a fluidized bed separation and enrichment method for rare earth element carrier minerals in mine solid waste. The method uses coal gangue from the Haerwusu coal mine with a particle size range of 6-1 mm for separation. The Haerwusu gangue contains lanthanum (La), cerium (Ce), and praseodymium (Pr) rare earth elements at contents of 100.3 ppm, 174.1 ppm, and 19.4 ppm, respectively. The method includes the following steps:

[0040] S1. The coal gangue from Haerwusu is crushed to below 6mm using a jaw crusher. After the coal gangue is crushed to the separation particle size in a closed circuit, it is used as the raw ore for the next enrichment and separation.

[0041] S2. A mixture of Geldart A-type coal powder and Geldart B-type ferrosilicon powder at a mass ratio of 2:8 is used as the separating medium for the fluidized bed 1 for sorting and enrichment. The Geldart A-type coal powder has a particle size of 45µm–74µm and a density of 1.2 g / cm³. 3 ~1.8g / cm 3 Geldart's Class B ferrosilicon powder has a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm³. 3 ~7.07g / cm 3 It is added to the sorting and enrichment fluidized bed 1.

[0042] S3. Based on the density, sorting particle size and rare earth element content of the coal gangue in Haerwusu, set the vibration frequency, amplitude parameters and pulse gas velocity of the vibrating gas-solid separation fluidized bed device. The vibration frequency is 20Hz, the amplitude parameter A is 2mm, and the pulse gas velocity is 46cm / s.

[0043] S4. Multiple pressure sensors 2 are installed at equal intervals along the body axis of the sorting and enriching fluidized bed 1. A vibration table 3 is provided below the sorting and enriching fluidized bed 1. All pressure sensors 2 monitor the pressure drop fluctuations in the inner layer of the vibrating gas-solid sorting fluidized bed and transmit the signals to the control system 5. The control system 5 monitors and regulates the density fluctuations and bed fluidization state of the vibrating gas-solid sorting fluidized bed 1 in real time.

[0044] S5. After setting the parameters of the sorting and enriching fluidized bed 1, the pulsed airflow and constant airflow are respectively passed through the pulsed airflow pipe 6 and the constant airflow pipe 7. The flow rate is regulated and controlled by the first flowmeter 61 and the second flowmeter 71. Vibration energy plays a dominant role in the sorting and enriching fluidized bed 1. The periodic vibration can organize the airflow to pass through the bed uniformly. Under the synergistic effect of vibration and airflow, the bed fluidization is uniform and stable, forming a uniform and stable dispersed fluidized environment. Density gradient stratification is carried out, with low-density materials distributed in the upper layer and high-density coal gangue products containing relatively high-grade rare earth elements enriched in the lower layer, realizing the sorting and pre-enrichment of rare earth elements in the rare earth element carrier minerals of mine solid waste.

[0045] After the sorting and pre-enrichment process, the content of rare earth elements was determined. The content of rare earth elements including lanthanum (La), cerium (Ce), and praseodymium (Pr) in the Haerwusu gangue reached the maximum, at 162.6 ppm, 279.3 ppm, and 32.8 ppm, respectively. The content of rare earth elements in the sorted product was higher than the national average standard for rare earth element content in coal gangue.

[0046] Example 2

[0047] This embodiment discloses a fluidized bed separation and enrichment method for rare earth element carrier minerals in mine solid waste. The method uses coal gangue from Linfen, Shanxi Province, with a particle size range of 6-1 mm. The contents of lanthanum (La), cerium (Ce), and praseodymium (Pr) rare earth elements in the Linfen gangue are 92.5 ppm, 178.6 ppm, and 18.7 ppm, respectively. The method includes the following steps:

[0048] S1. The coal gangue from Linfen, Shanxi Province, is crushed to below 6mm using a jaw crusher. After the coal gangue is crushed to the sorting particle size in a closed circuit, it is used as the raw ore for the next enrichment and sorting step.

[0049] S2. A mixture of Geldart A-type coal powder and Geldart B-type ferrosilicon powder at a mass ratio of 2:8 is used as the separating medium for the fluidized bed 1 for sorting and enrichment. The Geldart A-type coal powder has a particle size of 45µm–74µm and a density of 1.2 g / cm³. 3 ~1.8g / cm 3 Geldart's Class B ferrosilicon powder has a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm³. 3 ~7.07g / cm 3 It is added to the sorting and enrichment fluidized bed 1.

[0050] S3. Based on the density, sorting particle size and rare earth element content of the coal gangue in Haerwusu, set the vibration frequency, amplitude parameters and pulse gas velocity of the vibrating gas-solid separation fluidized bed device. The vibration frequency is 20Hz, the amplitude parameter A is 2mm, and the pulse gas velocity v is 46cm / s.

[0051] S4. Multiple pressure sensors 2 are installed at equal intervals along the body axis of the sorting and enriching fluidized bed 1. A vibration table 3 is provided below the sorting and enriching fluidized bed 1. All pressure sensors 2 monitor the pressure drop fluctuations in the inner layer of the vibrating gas-solid sorting fluidized bed and transmit the signals to the control system 5. The control system 5 monitors and regulates the density fluctuations and bed fluidization state of the vibrating gas-solid sorting fluidized bed 1 in real time.

[0052] S5. After setting the parameters of the sorting and enriching fluidized bed 1, the pulsed airflow and constant airflow are respectively passed through the pulsed airflow pipe 6 and the constant airflow pipe 7. The flow rate is regulated and controlled by the first flowmeter 61 and the second flowmeter 71. Vibration energy plays a dominant role in the sorting and enriching fluidized bed 1. The periodic vibration can organize the airflow to pass through the bed uniformly. Under the synergistic effect of vibration and airflow, the bed fluidization is uniform and stable, forming a uniform and stable dispersed fluidized environment. Density gradient stratification is carried out, with low-density materials distributed in the upper layer and high-density coal gangue products containing relatively high-grade rare earth elements enriched in the lower layer, realizing the sorting and pre-enrichment of rare earth elements in the rare earth element carrier minerals of mine solid waste.

[0053] After the sorting and pre-enrichment process, the content of rare earth elements was determined. The content of rare earth elements including lanthanum (La), cerium (Ce), and praseodymium (Pr) in the Haerwusu gangue reached the maximum, at 147.9 ppm, 287.6 ppm, and 230.2 ppm, respectively. The content of rare earth elements in the sorted product was higher than the national average standard for rare earth element content in coal gangue.

[0054] Comparative Example 1

[0055] This embodiment discloses a fluidized bed separation and enrichment method for rare earth element carrier minerals in mine solid waste. The method uses coal gangue from the Haerwusu coal mine with a particle size range of 6mm to 1mm for separation. The Haerwusu gangue contains lanthanum (La), cerium (Ce), and praseodymium (Pr) rare earth elements at contents of 100.3ppm, 174.1ppm, and 19.4ppm, respectively. The method includes the following steps:

[0056] S1. The coal gangue from Haerwusu is crushed to below 6mm using a jaw crusher. After the coal gangue is crushed to the separation particle size in a closed circuit, it is used as the raw ore for the next enrichment and separation.

[0057] S2. A mixture of Geldart A-type coal powder and Geldart B-type ferrosilicon powder at a mass ratio of 2:8 is used as the separating medium for the fluidized bed 1 for sorting and enrichment. The Geldart A-type coal powder has a particle size of 45µm–74µm and a density of 1.2 g / cm³. 3 ~1.8g / cm 3 Geldart's Class B ferrosilicon powder has a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm³. 3 ~7.07g / cm 3 It is added to the sorting and enrichment fluidized bed 1.

[0058] S3. Based on the density, sorting particle size and rare earth element content of the coal gangue in Haerwusu, set the vibration frequency, amplitude parameter and pulse gas velocity of the vibrating gas-solid separation fluidized bed device. The vibration frequency is 20Hz, the amplitude parameter A is 2mm, and the pulse gas velocity is v<30cm / s.

[0059] S4. Multiple pressure sensors 2 are installed at equal intervals along the body axis of the sorting and enriching fluidized bed 1. A vibration table 3 is provided below the sorting and enriching fluidized bed 1. All pressure sensors 2 monitor the pressure drop fluctuations in the inner layer of the vibrating gas-solid sorting fluidized bed and transmit the signals to the control system 5. The control system 5 monitors and regulates the density fluctuations and bed fluidization state of the vibrating gas-solid sorting fluidized bed 1 in real time.

[0060] S5. After setting the parameters of the sorting and enriching fluidized bed 1, the pulsed airflow and constant airflow are respectively passed through the pulsed airflow pipe 6 and the constant airflow pipe 7, and the flow rates are adjusted and controlled by the first flow meter 61 and the second flow meter 71. After starting the sorting and enriching fluidized bed 1, it was found that the bed did not fluidize and sorting and pre-enrichment could not be performed.

[0061] Comparative Example 2

[0062] This embodiment discloses a fluidized bed separation and enrichment method for rare earth element carrier minerals in mine solid waste. The method uses coal gangue from the Haerwusu coal mine with a particle size range of 6-1 mm for separation. The Haerwusu gangue contains lanthanum (La), cerium (Ce), and praseodymium (Pr) rare earth elements at contents of 100.3 ppm, 174.1 ppm, and 19.4 ppm, respectively. The method includes the following steps:

[0063] S1. The coal gangue from Haerwusu is crushed to below 6mm using a jaw crusher. After the coal gangue is crushed to the separation particle size in a closed circuit, it is used as the raw ore for the next enrichment and separation.

[0064] S2. A mixture of Geldart A-type coal powder and Geldart B-type ferrosilicon powder at a mass ratio of 2:8 is used as the separating medium for the fluidized bed 1 for sorting and enrichment. The Geldart A-type coal powder has a particle size of 45µm–74µm and a density of 1.2 g / cm³. 3 ~1.8g / cm 3 Geldart's Class B ferrosilicon powder has a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm³. 3 ~7.07g / cm 3 It is added to the sorting and enrichment fluidized bed 1.

[0065] S3. Based on the density, sorting particle size and rare earth element content of the coal gangue in Haerwusu, set the vibration frequency, amplitude parameter and pulse gas velocity of the vibrating gas-solid separation fluidized bed device. The vibration frequency is 20Hz, the amplitude parameter A is 2mm, and the pulse gas velocity is v>52cm / s.

[0066] S4. Multiple pressure sensors 2 are installed at equal intervals along the body axis of the sorting and enriching fluidized bed 1. A vibration table 3 is provided below the sorting and enriching fluidized bed 1. All pressure sensors 2 monitor the pressure drop fluctuations in the inner layer of the vibrating gas-solid sorting fluidized bed and transmit the signals to the control system 5. The control system 5 monitors and regulates the density fluctuations and bed fluidization state of the vibrating gas-solid sorting fluidized bed 1 in real time.

[0067] S5. After setting the parameters of the sorting and enriching fluidized bed 1, the pulsed airflow and constant airflow are respectively passed through the pulsed airflow pipe 6 and the constant airflow pipe 7, and the flow rate is adjusted and controlled by the first flowmeter 61 and the second flowmeter 71 fed back to the control system 5. After the sorting and enriching fluidized bed 1 is turned on, it is found that the bed is violently fluidized, and the gangue in the bed cannot be effectively stratified according to density. The content of rare earth elements such as lanthanum (La), cerium (Ce), and praseodymium (Pr) in the sinking particles shows a decreasing trend.

[0068] A comparison was made between existing conventional sorting and enrichment methods and the sorting and enrichment method of Example 1 of this invention. The results are shown in Table 1. Using the technology of this invention to sort coal gangue increased the content of rare earth element carrier minerals in the raw ore by 1.61 times. Using flotation, magnetic separation, wet heavy media separation, and photoelectric separation technologies to sort coal gangue resulted in enrichment factors of 1.42, 1.35, 1.58, and 1.37 for rare earth element carrier minerals, respectively. These enrichment effects were lower than those of the method in this study. Furthermore, flotation and wet heavy media separation present the problem of wastewater treatment after sorting, magnetic separation cannot enrich rare earth elements in non-magnetic materials, and photoelectric separation has low efficiency and small processing capacity. Therefore, the method of this invention can achieve large-scale and precise sorting of rare earth element carrier minerals in coal gangue.

[0069] Table 1 compares the sorting and enrichment methods of existing conventional technologies with the sorting and enrichment method of Embodiment 1 of the present invention.

[0070]

[0071] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0072] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fluidized separation and enrichment method for rare earth element carrier minerals from mine solid waste, characterized in that: The following steps are involved: A mixture of pulverized coal and ferrosilicon powder is used as a sorting medium and added into a vibrating gas-solid sorting fluidized bed device. The vibration frequency, amplitude parameters and gas velocity of the pulse airflow of the vibrating gas-solid sorting fluidized bed device are set according to the density, sorting particle size and rare earth element content of the rare earth element carrier minerals in the mine solid waste. Under the synergistic effect of vibration and airflow of the vibrating gas-solid sorting fluidized bed, the rare earth element carrier minerals in the mine solid waste form a dispersed fluidized environment with uniform and stable density, and density gradient stratification is carried out to realize the sorting pre-enrichment of rare earth elements in the rare earth element carrier minerals in the mine solid waste.

2. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 1, characterized in that: The density of the rare earth element carrier mineral in the mine solid waste is ≥2.0g / cm 3 .

3. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 1, characterized in that: The mass ratio of coal powder to ferrosilicon powder is 1:4-9.

4. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 1, characterized in that: The coal powder is Geldart A-type coal powder with a particle size of 45um to 74um and a density of 1.2g / cm 3 ~1.8g / cm 3 The ferrosilicon powder is Geldart B type ferrosilicon powder with a particle size of 0.074 mm to 0.4 mm and a density of 6.55 g / cm 3 ~7.07g / cm 3。 5. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 1, characterized in that: The vibration frequency is 10 Hz to 50 Hz, the amplitude is 1 mm to 5 mm, and the gas flow rate is adjusted to 30 cm / s to 50 cm / s.

6. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 1, characterized in that: The vibrating gas-solid separation fluidized bed device comprises a separation and enrichment fluidized bed (1), a plurality of pressure sensors (2) are equidistantly installed along the axial position of the separation and enrichment fluidized bed (1), a vibration table (3) is provided below the separation and enrichment fluidized bed (1), and a dust removal device (4) is provided above the separation and enrichment fluidized bed (1), all the pressure sensors (2) and the vibration table (3) are signal-connected to a control system (5), the pressure drop fluctuation of the inner layer of the vibrating gas-solid separation fluidized bed is monitored by all the pressure sensors (2), and the signal is transmitted to the control system (5), and the control system (5) monitors and controls the density fluctuation and bed fluidization state of the vibration table (3) in real time.

7. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 6, characterized in that: The vibration table (3) is provided with a pulse airflow pipe (6) and a constant airflow pipe (7), the outlets of the pulse airflow pipe (6) and the constant airflow pipe (7) are both located directly below the enrichment fluidized bed (1), the pulse airflow pipe (6) is provided with a first flow meter (61), a first valve (62) and a butterfly valve (63), and the constant airflow pipe (7) is provided with a second flow meter (71) and a second valve (72).

8. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 7, characterized in that: The first flow meter (61), the first valve (62), the second flow meter (71) and the second valve (72) are all connected to the control system (5) via signals.

9. The method for fluidizing pre-enrichment of rare earth element carrier minerals from mountain solid waste according to claim 1, characterized in that: The carrier mineral of rare earth elements in mining solid waste is coal gangue.

10. The method for fluidized separation and enrichment of rare earth element carrier minerals from mine solid waste according to claim 1, characterized in that: After the separation and pre-enrichment is completed, the lower layer in the vibrating gas-solid separation fluidized bed is the rare earth elements.

Images