A short process of grinding and flotation for processing fine molybdenite

Abstract

The present application belongs to the field of non-ferrous metal dressing process, and relates to a grinding-flotation short process separation method for processing fine molybdenite. The process uses a high-pressure roller mill and a tower mill crushing and grinding process to replace the fine crushing and two-stage continuous ball milling operation in the traditional crushing and grinding process, and uses a flotation column to replace a flotation machine for flotation operation, thereby simplifying the production process flow of molybdenite. The present application has the advantages that the high-pressure roller mill and the tower mill change the crushing and grinding mode of the ore, significantly reduce the crushing and grinding energy consumption, and more effectively protect the flaky structure of molybdenite. The particle size distribution of the grinding product is reasonable, and the amount of fine and micro-fine particles (-20 μm) is reduced, thereby creating good conditions for the flotation operation. The flotation column is used for flotation, compared with the flotation machine, the recycling of middling slurry is reduced, the fine molybdenite that has been dissociated is fully recovered, and the recovery rate of molybdenite is improved. In addition, the flotation column flotation is beneficial to obtaining high-grade concentrate product, and improves the separation index and economic benefits of molybdenite.

Description

Technical Field

[0001] This invention belongs to the field of non-ferrous metal beneficiation technology, and in particular relates to a short-process separation method of grinding-flotation for processing fine-grained molybdenite. Background Technology

[0002] With the continuous development of the national industrial economy, the demand for molybdenum metal has gradually increased, and the efficient development and utilization of molybdenite resources has attracted widespread attention. Due to the good natural floatability of molybdenite, froth flotation is the most effective method for separating it. In the beneficiation process of molybdenite, the most common process involves three stages of closed-circuit crushing, one stage of ball milling (for fine-grained disseminated materials entering flotation, two stages of continuous ball milling are required), one roughing stage, two to three scavenging stages, and six to seven re-grinding stages of the rough concentrate (e.g.,...). Figure 2 As shown in the figure, the overall process is lengthy, the grinding energy consumption is high, the number of equipment is large, and the operation and maintenance work is heavy.

[0003] Molybdenite belongs to the hexagonal crystal system and has a lamellar crystal structure. During crushing and grinding, molybdenite readily dissociates along the interlayer, occurring as platy particles and exposing nonpolar hydrophobic "surfaces" and polar hydrophilic "facets." During crushing and grinding, the "surface" structure is disrupted, and the number of "facets" increases, leading to a decrease in the floatability of molybdenite particles and an increase in fine particles. This severely affects flotation efficiency, resulting in lower molybdenite concentrate grade and recovery rate, and increased consumption of flotation reagents. Crushing and grinding are crucial steps in mineral processing, separating valuable minerals from gangue minerals and providing suitable particle size for separation operations. The energy consumption of crushing and grinding operations accounts for 60%-70% of the total energy consumption of the entire mineral processing plant. Therefore, the crushing and grinding effect directly impacts production costs and flotation performance. High-pressure roller mills implement quasi-static pressure material layer crushing. Compared with traditional fine crushing equipment, their crushed products have more micro-cracks, higher fine particle content, and lower grinding Bond work index. Using high-pressure roller mills can reduce the feed particle size, effectively reducing grinding energy consumption and increasing mill productivity. Tower mills primarily use shear force to grind minerals and are commonly used in fine material grinding operations. Compared with horizontal ball mills, they have advantages such as higher grinding efficiency, lower grinding energy consumption, more uniform product particle size, and prevention of over-grinding. Optimization of molybdenite crushing and grinding processes will help reduce production costs and improve sorting indicators.

[0004] Molybdenite separation commonly employs flotation, but the raw ore grade is low, while the concentrate grade requirement is high. Flotation processes using flotation machines involve multiple cleaning stages, resulting in a complex process. During these multiple separation stages, it is often difficult to simultaneously achieve high grade and high recovery rate of the molybdenum concentrate. Flotation columns are a commonly used type of flotation equipment. Mineral particles and microbubbles flow countercurrently, increasing the probability of collision and contact between particles and bubbles, providing ample opportunities for particle capture. Compared to flotation machines, flotation columns have a thicker froth layer, and the addition of flushing water provides a cleaning effect. Therefore, flotation columns have a higher enrichment ratio, significantly improving the grade of the flotation concentrate. Existing research indicates that a single flotation column can replace the separation effect of two to three flotation machines. Therefore, optimizing the molybdenite separation process is essential. Shortening the separation process and reducing the number of internal pulp circulation stages are crucial for improving molybdenite flotation performance. Summary of the Invention

[0005] To address the aforementioned problems in the separation of molybdenite, this invention provides a short-process grinding-flotation separation method for processing fine-grained molybdenite, aiming to shorten the separation process of crushing and flotation operations, effectively reduce crushing energy consumption, improve flotation separation efficiency, and reduce production costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A short-process grinding and flotation separation method for processing fine-grained molybdenite includes the following steps:

[0008] Step 1: The raw ore is crushed using a jaw crusher and a cone crusher. The crushed product is screened by a linear vibrating screen. The product on the screen is returned to the cone crusher for further crushing. The product under the screen is a crushed product with a particle size ≤30mm.

[0009] Step 2: The crushed product from Step 1 is subjected to ultra-fine crushing using a high-pressure roller mill. The ultra-fine crushed material is then screened by a micro powder sieve. The product on the sieve is returned to the high-pressure roller mill for further crushing, while the product under the sieve is an ultra-fine crushed product with a particle size ≤2mm.

[0010] Step 3: The ultrafine crushed product from Step 2 is mixed with water to prepare a slurry, which is then fed into a tower mill for grinding. The ground product is fed into a hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the tower mill, and the overflow from the hydrocyclone is fine material with a content of -200 mesh (80%-85%).

[0011] Step 4: The fine particles from Step 3 are fed into the mixing tank and reagents are added to adjust the slurry. Then the slurry is fed into the first stage of flotation. The first stage of flotation uses a flotation column to perform one roughing and one scavenging. The scavenging concentrate is returned to the roughing operation, and the rough concentrate enters the second stage of grinding and flotation. The scavenging tailings are the final tailings.

[0012] The coarse concentrate from steps 5 and 4 is fed into a second-stage hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the second-stage tower mill, and the overflow from the hydrocyclone is fine material with a particle size of -400 mesh and ≥85%.

[0013] The fine-grained materials from steps 6 and 5 are fed into the second-stage flotation operation. The second-stage flotation operation uses a flotation column for two cleaning processes. The tailings from the first cleaning process are returned to the first-stage roughing operation, and the tailings from the second cleaning process are returned to the first cleaning process in the second stage. The concentrate from the second cleaning process is a high-grade molybdenum concentrate.

[0014] Furthermore, in steps 1 and 2 above, the linear vibrating screen and the micro powder screen are dry screening operations; the high-pressure roller mill has a roller grinding pressure of 3.0MPa-4.0MPa and a roller gap of 14mm-18mm. Under these conditions, the key technical parameters of the high-pressure roller mill can be kept stable, and the grinding operation can be carried out smoothly.

[0015] Furthermore, in step 3 above, the grinding concentration of the tower mill is 60%-65%, the diameter of the steel ball media is 25mm, and the media filling rate is 60%-65%. Under these conditions, the slurry volume in the grinding and classification process of the tower mill and hydrocyclone is stable, the product particle size fluctuation is small, and the classification effect is optimal, providing good conditions for the stable operation of subsequent flotation operations.

[0016] Furthermore, in step 4 above, the flotation reagent dosage for the first roughing operation is as follows: lime 600-800g / t raw ore, depressant 800-1000g / t raw ore, kerosene 120-150g / t raw ore, and No. 2 oil 50-70g / t raw ore.

[0017] Furthermore, in step 4 above, the flotation reagent dosage for the first stage of scavenging operation is: 40-60g / t of kerosene and 15g / t of No. 2 oil.

[0018] Furthermore, in step 6 above, the flotation reagent dosage for the two-stage primary cleaning operation is as follows: 200-300 g / t raw ore inhibitor, 30-50 g / t raw ore kerosene, and 10-15 g / t raw ore No. 2 oil.

[0019] Preferably, the inhibitor is prepared by mixing water glass and sodium hexametaphosphate in a mass ratio of 9:1. Under this reagent regimen, the flotation column can be guaranteed to operate stably and smoothly, and good separation indicators can be obtained.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows.

[0021] The short-process grinding and flotation method of the present invention uses a high-pressure roller mill, a tower mill, and a flotation column, which changes the original grinding and flotation process of molybdenite and greatly shortens the production process. Compared with the traditional molybdenite ore beneficiation process, it has the following advantages.

[0022] (1) To process fine-grained molybdenite, under the condition that the particle size of the feed material is required to be 80%-85% of -200 mesh, a short crushing and grinding process is formed by high pressure roller mill and tower mill to replace the traditional fine crushing and two-stage ball milling process. The process is simple and compact, efficient and energy-saving, and the crushing and grinding energy consumption is reduced by 30%.

[0023] (2) The high-pressure roller mill implements quasi-static pressure material layer crushing, while the tower mill grinds the material by shearing. At the same time, the tower mill can prevent over-grinding, which is beneficial to protect the platy structure of molybdenite, reduce the generation of fine particles (-20μm) material, provide good material particle size conditions for flotation operation, and improve the separation effect of molybdenite.

[0024] (3) The flotation column replaces the lengthy flotation process of the flotation machine, reduces the number of equipment, simplifies the flotation process, and helps to reduce production costs; the flotation column has a high enrichment ratio, which helps to improve the separation index; the combined grinding and flotation short process, compared with the traditional molybdenite separation process, increases the grade of molybdenum concentrate by 1-3 percentage points and the recovery rate by 3-6 percentage points. Attached Figure Description

[0025] Figure 1 This is a flow chart of the short process separation of molybdenite grinding and flotation according to the present invention.

[0026] Figure 2 This is a flowchart of the traditional molybdenite beneficiation process. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] A short-process grinding and flotation separation method for processing fine-grained molybdenite includes the following steps:

[0029] Step 1: The raw ore is crushed using a jaw crusher and a cone crusher. The crushed product is screened by a linear vibrating screen (dry screening operation). The product on the screen is returned to the cone crusher for further crushing. The product under the screen is a crushed product with a particle size ≤30mm.

[0030] Step 2: The crushed product from Step 1 is subjected to ultra-fine crushing using a high-pressure roller mill. The ultra-fine crushed material is then screened using a micro powder sieve (dry screening operation). The product on the sieve is returned to the high-pressure roller mill for further crushing. The pressure is 3.0MPa-4.0MPa, the roller gap is 14mm-18mm, and the product under the sieve is an ultra-fine crushed product with a particle size ≤2mm.

[0031] Step 3: The ultrafine crushed product from Step 2 is mixed with water to prepare a slurry, which is then fed into a tower mill for grinding. The grinding concentration in the tower mill is 60%-65%, the diameter of the steel ball media is 25mm, and the media filling rate is 60%-65%. The ground product is fed into a hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the tower mill, and the overflow from the hydrocyclone is fine material with a content of -200 mesh (80%-85%).

[0032] Step 4: The fine-grained material from Step 3 is fed into a mixing tank and reagents are added to adjust the slurry. Then, the slurry is fed into the first-stage flotation operation. The first-stage flotation operation uses a flotation column for one roughing and one scavenging. The flotation reagent dosage for the first-stage roughing operation is: lime 600-800g / t raw ore, depressant (made of water glass and sodium hexametaphosphate in a mass ratio of 9:1) 800-1000g / t raw ore, kerosene 120-150g / t raw ore, and No. 2 oil 50-70g / t raw ore. The flotation reagent dosage for the first-stage scavenging operation is: kerosene 40-60g / t raw ore and No. 2 oil 15g / t raw ore. The scavenging concentrate is returned to the roughing operation, and the rough concentrate enters the second-stage grinding and flotation operation. The scavenging tailings are the final tailings.

[0033] The coarse concentrate from steps 5 and 4 is fed into a second-stage hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the second-stage tower mill, and the overflow from the hydrocyclone is fine material with a particle size of -400 mesh and ≥85%.

[0034] The fine particles from steps 6 and 5 are fed into the second-stage flotation operation. The second-stage flotation operation uses a flotation column for two cleaning processes. The flotation reagent dosage for the first cleaning process in the second stage is as follows: inhibitor (made of water glass and sodium hexametaphosphate in a mass ratio of 9:1) 200-300 g / t of raw ore, kerosene 30-50 g / t of raw ore, and No. 2 oil 10-15 g / t of raw ore. The tailings from the first cleaning process are returned to the first-stage roughing operation, and the tailings from the second cleaning process are returned to the first cleaning process in the second stage. The concentrate from the second cleaning process is a high-grade molybdenum concentrate.

[0035] Example 1.

[0036] The fine-grained molybdenite ore from a certain area has a molybdenum grade of 0.083%. The main target mineral is molybdenite, and the main gangue minerals are quartz, plagioclase, potassium feldspar, mica, etc.

[0037] Step 1: The raw ore is crushed using a jaw crusher and a cone crusher. The crushed product is dry-screened using a linear vibrating screen. The product on the screen is returned to the cone crusher for further crushing. The product under the screen is a crushed product with a particle size ≤30mm.

[0038] Step 2: The crushed product from Step 1 is subjected to ultrafine crushing using a high-pressure roller mill. The roller mill pressure is 4.0 MPa and the roller gap is 18 mm. The ultrafine crushed material is then subjected to dry screening using a micro powder sieve. The product on the sieve is returned to the high-pressure roller mill for further crushing, and the product under the sieve is an ultrafine crushed product with a particle size ≤2 mm.

[0039] Step 3: The ultrafine crushed product from Step 2 is mixed with water to prepare a slurry, which is then fed into a tower mill for grinding. The grinding concentration in the tower mill is 65%, the diameter of the steel balls is 25mm, and the media filling rate is 60%. The ground product is fed into a hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the tower mill, and the overflow from the hydrocyclone is fine material with a content of -200 mesh (82.30%).

[0040] Step 4: The fine-grained materials from Step 3 are fed into a mixing tank and reagents are added to adjust the slurry. Then, the slurry is fed into the first-stage flotation operation. The first-stage flotation operation uses a flotation column for one roughing and one scavenging. The scavenging concentrate is returned to the roughing operation, and the rough concentrate enters the second-stage grinding and flotation operation. The scavenging tailings are the final tailings. In the flotation operation, the flotation reagent dosage for the first-stage roughing operation is: lime 600g / t raw ore, depressant (water glass and sodium hexametaphosphate = 9:1) 800g / t raw ore, kerosene 120g / t raw ore, and No. 2 oil 50g / t raw ore. The flotation reagent dosage for the first-stage scavenging operation is: kerosene 40g / t raw ore and No. 2 oil 15g / t raw ore.

[0041] The coarse concentrate from steps 5 and 4 is fed into a second-stage hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the second-stage tower mill, and the overflow from the hydrocyclone is fine material with a content of -400 mesh (87.54%).

[0042] Step 6: The fine-grained material from Step 5 is fed into the second-stage flotation operation. The second-stage flotation operation uses a flotation column for two cleaning processes. The tailings from the first cleaning process are returned to the first-stage roughing process, and the tailings from the second cleaning process are returned to the first cleaning process in the second stage. The concentrate from the second cleaning process is a high-grade molybdenum concentrate. In the second-stage flotation operation, the flotation reagent dosage for the first cleaning process is as follows: 200g / t raw ore of depressant (water glass and sodium hexametaphosphate = 9:1), 30g / t raw ore of kerosene, and 10g / t raw ore of No. 2 oil.

[0043] Example 1 and Comparative Example (by Figure 2 The results of the flowchart are shown in Table 1 below.

[0044] Table 1. Sorting results of Example 1 and the comparative example.

[0045]

[0046] As shown in the table above, when using the grinding-flotation short-process separation method, under the condition that the content of -200 mesh is similar in grinding fineness, the proportion of -20μm particle size in the grinding product of the example is 8.67 percentage points lower than that of the comparison, the final molybdenum concentrate grade is increased by 1.18 percentage points, and the recovery rate is increased by 4.28 percentage points.

[0047] Example 2.

[0048] The fine-grained molybdenite ore from a certain area has a molybdenum grade of 0.074%. The main target mineral is molybdenite, and the main gangue minerals are quartz, orthoclase, biotite, plagioclase, calcite, etc.

[0049] Step 1: The raw ore is crushed using a jaw crusher and a cone crusher. The crushed product is dry-screened using a linear vibrating screen. The product on the screen is returned to the cone crusher for further crushing. The product under the screen is a crushed product with a particle size ≤30mm.

[0050] Step 2: The crushed product from Step 1 is subjected to ultrafine crushing using a high-pressure roller mill. The roller mill pressure is 3.5 MPa and the roller gap is 14 mm. The ultrafine crushed material is then subjected to dry screening using a micro powder sieve. The product on the sieve is returned to the high-pressure roller mill for further crushing, and the product under the sieve is an ultrafine crushed product with a particle size ≤2 mm.

[0051] Step 3: The ultrafine crushed product from Step 2 is mixed with water to prepare a slurry, which is then fed into a tower mill for grinding. The grinding concentration in the tower mill is 60%, the diameter of the steel balls is 25mm, and the media filling rate is 65%. The ground product is fed into a hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the tower mill, and the overflow from the hydrocyclone is fine material with a content of -200 mesh (84.50%).

[0052] Step 4: The fine-grained materials from Step 3 are fed into a mixing tank and reagents are added to adjust the slurry. Then, the slurry is fed into the first-stage flotation operation. The first-stage flotation operation uses a flotation column for one roughing and one scavenging. The scavenging concentrate is returned to the roughing operation, and the rough concentrate enters the second-stage grinding and flotation operation. The scavenging tailings are the final tailings. In the flotation operation, the flotation reagent dosage for the first-stage roughing operation is: lime 800g / t raw ore, depressant (water glass and sodium hexametaphosphate = 9:1) 1000g / t raw ore, kerosene 150g / t raw ore, and No. 2 oil 70g / t raw ore. The flotation reagent dosage for the first-stage scavenging operation is: kerosene 60g / t raw ore and No. 2 oil 15g / t raw ore.

[0053] The coarse concentrate from steps 5 and 4 is fed into a second-stage hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the second-stage tower mill, and the overflow from the hydrocyclone is fine material with a content of -400 mesh (88.13%).

[0054] The fine-grained materials from steps 6 and 5 are fed into the second-stage flotation operation. The second-stage flotation operation employs two cleaning processes using flotation columns. The tailings from the first cleaning process are returned to the first-stage roughing operation, and the tailings from the second cleaning process are returned to the first cleaning process in the second stage. The concentrate from the second cleaning process is a high-grade molybdenum concentrate. In the second-stage flotation operation, the flotation reagent dosage for the first cleaning process is as follows: 300g / t raw ore of depressant (water glass and sodium hexametaphosphate = 9:1), 50g / t raw ore of kerosene, and 15g / t raw ore of No. 2 oil.

[0055] Example 2 and Comparative Example (by Figure 2 The results of the flowchart are shown in Table 2 below.

[0056] Table 2. Sorting results of Example 2 and the comparative example.

[0057]

[0058] As shown in the table above, when using the grinding-flotation short-process separation method, under the condition that the content of -200 mesh is similar in grinding fineness, the proportion of -20μm particle size in the grinding product of the example is 7.95 percentage points lower than that of the comparison, the final molybdenum concentrate grade is increased by 1.22 percentage points, and the recovery rate is increased by 4.65 percentage points.

[0059] Example 3.

[0060] The fine-grained molybdenite ore from a certain area has a molybdenum grade of 0.079%. The main target mineral is molybdenite, and the main gangue minerals are quartz, feldspar, muscovite, kaolinite, calcite, etc.

[0061] Step 1: The raw ore is crushed using a jaw crusher and a cone crusher. The crushed product is dry-screened using a linear vibrating screen. The product on the screen is returned to the cone crusher for further crushing. The product under the screen is a crushed product with a particle size ≤30mm.

[0062] Step 2: The crushed product from Step 1 is subjected to ultrafine crushing using a high-pressure roller mill. The roller mill pressure is 3.0 MPa and the roller gap is 16 mm. The ultrafine crushed material is then subjected to dry screening using a micro powder sieve. The product on the sieve is returned to the high-pressure roller mill for further crushing, and the product under the sieve is an ultrafine crushed product with a particle size ≤2 mm.

[0063] Step 3: The ultrafine crushed product from Step 2 is mixed with water to prepare a slurry, which is then fed into a tower mill for grinding. The grinding concentration in the tower mill is 65%, the diameter of the steel balls is 25mm, and the media filling rate is 63%. The ground product is fed into a hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the tower mill, and the overflow from the hydrocyclone is fine material with a content of -200 mesh (83.75%).

[0064] Step 4: The fine-grained materials from Step 3 are fed into a mixing tank and reagents are added to adjust the slurry. Then, the slurry is fed into the first-stage flotation operation. The first-stage flotation operation uses a flotation column for one roughing and one scavenging. The scavenging concentrate is returned to the roughing operation, and the rough concentrate enters the second-stage grinding and flotation operation. The scavenging tailings are the final tailings. In the flotation operation, the flotation reagent dosage for the first-stage roughing operation is: lime 600g / t raw ore, depressant (water glass and sodium hexametaphosphate = 9:1) 900g / t raw ore, kerosene 140g / t raw ore, and No. 2 oil 60g / t raw ore. The flotation reagent dosage for the first-stage scavenging operation is: kerosene 50g / t raw ore and No. 2 oil 15g / t raw ore.

[0065] The coarse concentrate from steps 5 and 4 is fed into a second-stage hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the second-stage tower mill, and the overflow from the hydrocyclone is fine material with a content of -400 mesh (89.27%).

[0066] The fine-grained materials from steps 6 and 5 are fed into the second-stage flotation operation. The second-stage flotation operation employs two cleaning processes using flotation columns. The tailings from the first cleaning process are returned to the first-stage roughing operation, and the tailings from the second cleaning process are returned to the first cleaning process in the second stage. The concentrate from the second cleaning process is a high-grade molybdenum concentrate. In the second-stage flotation operation, the flotation reagent dosage for the first cleaning process is as follows: 200g / t raw ore depressant (water glass and sodium hexametaphosphate = 9:1), 40g / t raw ore kerosene, and 15g / t raw ore No. 2 oil.

[0067] Example 3 and Comparative Example (by Figure 2 The results of the flowchart are shown in Table 3 below.

[0068] Table 3. Sorting results of Example 3 and the comparative example.

[0069]

[0070] As shown in the table above, when using the grinding-flotation short-process separation method, under the condition that the content of -200 mesh is similar in grinding fineness, the proportion of -20μm particle size in the grinding product of the example is 9.07 percentage points lower than that of the comparison, the final molybdenum concentrate grade is increased by 1.68 percentage points, and the recovery rate is increased by 5.62 percentage points.

Claims

1. A short-process grinding-flotation separation method for processing fine-grained molybdenite, characterized in that, Includes the following steps: Step 1: The raw ore is crushed using a jaw crusher and a cone crusher. The crushed product is screened by a linear vibrating screen. The product on the screen is returned to the cone crusher for further crushing. The product under the screen is a crushed product with a particle size ≤30mm. Step 2: The crushed product from Step 1 is subjected to ultra-fine crushing using a high-pressure roller mill. The ultra-fine crushed material is then screened by a micro powder sieve. The product on the sieve is returned to the high-pressure roller mill for further crushing, while the product under the sieve is an ultra-fine crushed product with a particle size of ≤2mm. Step 3: The ultrafine crushed product from Step 2 is mixed with water to prepare a slurry, which is then fed into a tower mill for grinding. The ground product is fed into a hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the tower mill, and the overflow from the hydrocyclone is fine material with a content of -200 mesh (80%-85%). Step 4: The fine-grained materials from Step 3 are fed into the mixing tank and reagents are added to adjust the slurry. Then the slurry is fed into the first stage of flotation. The first stage of flotation uses a flotation column to perform one roughing and one scavenging. The scavenging concentrate is returned to the roughing operation, and the rough concentrate enters the second stage of grinding and flotation. The scavenging tailings are the final tailings. The coarse concentrate from steps 5 and 4 is fed into a second-stage hydrocyclone for classification. The underflow product from the hydrocyclone is returned to the second-stage tower mill, and the overflow from the hydrocyclone is fine material with a particle size of -400 mesh and ≥85%. The fine-grained materials from steps 6 and 5 are fed into the second-stage flotation operation. The second-stage flotation operation uses a flotation column for two cleaning processes. The tailings from the first cleaning process are returned to the first-stage roughing operation, and the tailings from the second cleaning process are returned to the first cleaning process in the second stage. The concentrate from the second cleaning process is a high-grade molybdenum concentrate. The dosage of reagents for the primary roughing flotation in step 4 is as follows: lime 600-800g / t raw ore, depressant 800-1000g / t raw ore, kerosene 120-150g / t raw ore, and No. 2 oil 50-70g / t raw ore; The flotation reagent dosage for the two-stage primary cleaning operation in step 6 is as follows: 200-300 g / t raw ore inhibitor, 30-50 g / t raw ore kerosene, and 10-15 g / t raw ore No. 2 oil; In step 4 or step 6, the inhibitor is prepared by water glass and sodium hexametaphosphate in a mass ratio of 9:

1. The high-pressure roller mill, the tower mill, and the flotation column are used together to form a short grinding and flotation process, which yields a molybdenum concentrate with a grade of ≥50% and a recovery rate of ≥88%.

2. The grinding-flotation short-process separation method for processing fine-grained molybdenite according to claim 1, characterized in that, The linear vibrating screen and micro powder screen mentioned in steps 1 and 2 are dry screening methods.

3. The grinding-flotation short-process separation method for processing fine-grained molybdenite according to claim 1, characterized in that, The high-pressure roller mill described in step 2 has a roller milling pressure of 3.0MPa-4.0MPa and a roller gap of 14mm-18mm.

4. The grinding-flotation short-process separation method for processing fine-grained molybdenite according to claim 1, characterized in that, The grinding concentration of the tower mill described in step 3 is 60%-65%, the diameter of the steel ball media is 25mm, and the media filling rate is 60%-65%.

5. The grinding-flotation short-process separation method for processing fine-grained molybdenite according to claim 1, characterized in that, The dosage of flotation reagents in step 4 is as follows: 40-60 g / t of kerosene and 15 g / t of No. 2 oil.

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