Surface hydrophobicity coated dense medium flotation apparatus and process

Abstract

The application discloses a kind of surface hydrophobicity coated heavy medium flotation equipment and process, belong to mineral processing technical field.The flotation equipment includes flotation tank (7) and concentrate port (7), the inner bottom surface of flotation tank (7) is inclined surface, and inclines to concentrate port (10) place.Process includes: S1, grinding obtains raw ore pulp;S2, surface coated rubber's heavy medium (11) and raw ore pulp are given to flotation equipment according to proportion;S3, strong stirring and in addition kerosene, 2# oil is stirred again, aerofloat obtains concentrate and tailings;S4, weak magnetic separation, separates heavy medium particle.This process is simple and easy to operate, equipment is simple, moving parts are few, work is stable, energy consumption is low, the existing flotation machine is simply transformed to creatively combine heavy medium beneficiation and flotation together, realizes that the specific gravity is higher, and the heavy suspension liquid that internal heavy medium distribution is more uniform;And heavy quality is recovered well, loss is very little in beneficiation process, with development application prospect.

Description

Technical Field

[0001] This invention discloses a surface hydrophobic coated heavy medium flotation device and process, belonging to the field of mineral processing technology. Background Technology

[0002] Heavy medium separation (HMS) is the process of separating mineral particles in a heavy medium. Its basic principle is Archimedes' principle, which utilizes the principle of float and sink to separate minerals with different specific gravities in a straight-flow or two-phase fluid. The specific gravity of the separating medium is between the specific gravities of the mineral particles being separated. The less dense particles float, while the more dense particles sink, thus achieving the separation purpose. Heavy medium refers to media with a density greater than water (1 g / cm³). 3 Specific gravity is a heavy liquid or heavy suspension fluid. Also known as relative density, the specific gravity of a solid or liquid is the density of that substance (in its completely dense state) compared to its density at standard atmospheric pressure and the density of pure H₂O at 3.98°C (999.972 kg / m³). 3 The ratio of specific gravity to 1 / 2. Specific gravity is a dimensionless quantity, meaning it has no unit value and generally varies with temperature and pressure.

[0003] To achieve the purpose of separation, the density of the heavy liquid or heavy suspension fluid prepared with heavy medium should be between that of heavy minerals and light minerals, that is: ρlight < ρheavy liquid or heavy suspension < ρheavy. Therefore, in such a medium, light minerals float and heavy minerals sink, thus achieving the purpose of separation.

[0004] The separation is carried out according to Archimedes' principle of buoyancy, but in order to improve production efficiency, centrifugal force or other mechanical forces are generally introduced to increase the stratification speed of light and heavy minerals in heavy liquids or heavy suspensions.

[0005] There are two types of existing heavy media:

[0006] 1. Heavy liquid – is an organic liquid or an aqueous solution of a high-density salt with a density greater than that of water;

[0007] 2. Heavy suspension (made by grinding extremely dense solid particles into fine particles and then mixing them with water). Due to the high price and toxicity of heavy liquids, they are rarely used in production.

[0008] Heavy media used in industry are all heavy suspensions. Heavy media particles are often trapped in concentrates and tailings, requiring high-frequency vibration of a desliming screen to separate the heavy media trapped in the concentrates and tailings, thus achieving the recovery of these heavy media. This process is technically called media regeneration.

[0009] The method has limitations: Theoretically, a specific gravity difference of only 0.1 can separate two minerals. However, in actual production, when separating metal ores using heavy media, the density of the heavy media (solid particles used to prepare heavy suspensions) makes it difficult to prepare suspensions with very high densities. Furthermore, heavier particles settle faster in water, making it impossible to maintain a uniform specific gravity suspension for an extended period. Generally, only heavy media suspensions with a density slightly higher than that of the lighter minerals can be prepared.

[0010] For example, the specific gravity of heavy media suspensions prepared with ferrosilicon can reach up to 3.8, while that of ilmenite is 4.4–5, and that of pyroxene and olivine is 3.6–3.9 and 3.6–4.1, respectively. Therefore, heavy media separation is difficult to apply to the beneficiation of metallic ores. However, clean coal and coal gangue have a significant difference in specific gravity, and both are relatively low. It is easy to prepare heavy media suspensions with specific gravities between those of clean coal and coal gangue for coal preparation. Therefore, heavy media are currently mainly used in the coal preparation industry, and have significant limitations in the separation of non-ferrous minerals.

[0011] Therefore, in the beneficiation of metal ores, especially non-ferrous minerals, it is difficult to obtain high-grade final concentrates using heavy media separation methods. This is because many gangue minerals have a higher specific gravity than the prepared heavy media suspension, which can only remove low-density individual gangue or surrounding rock mixed in during mining. This method can only be used as a pre-separation step. Theoretically, as long as there is a specific gravity difference of 0.1, heavy media separation can separate the two minerals. However, current technologies and publicly available reports have not been able to configure the specific gravity of the heavy media suspension to the theoretically required specific gravity for separating metal minerals.

[0012] Flotation refers to the use of surfactants—foaming agents—that generate a large number of bubbles. When air is introduced into water or when air is introduced into the water due to agitation, the hydrophobic end of the surfactant is oriented towards the air bubble at the gas-liquid interface, while the hydrophilic end remains in the solution, forming a bubble. Another surfactant (usually a cationic surfactant, but also including aliphatic amines) acts as a trapping agent, adsorbing onto the surface of the solid mineral powder. This adsorption has a certain selectivity depending on the mineral properties. Its basic principle is to utilize the lattice defects on the crystal surface, allowing the outward-facing hydrophobic end to partially insert into the bubble.

[0013] Based on the above principles, in a flotation machine, after the slurry has been treated with reagents, it is agitated and aerated, causing some mineral particles to selectively adhere to the air bubbles. These particles float to the surface of the slurry and are scraped off to form a frothy product, while the rest remain in the slurry, thus achieving mineral separation. There are many structural forms of flotation machines, the most common being the mechanically agitated flotation machine, used for mineral processing. Flotation is suitable for processing fine and micro-fine particles; particles smaller than 10μm, which are difficult to recover using other mineral processing methods, can also be processed by flotation. Some flotation technologies specifically designed for ultrafine particles have even lower recoverable particle sizes. Ultrafine flotation and ion flotation technologies can recover various substances from colloidal particles to those in molecular and ionic states. Flotation can also separate intermediate products, volatiles, and useful components from pyrometallurgical slags; treat leaching slags and displacement precipitation products from hydrometallurgical processes; recover chemical products (such as pulp, surfactants, etc.); and recover inorganic and organic matter from wastewater.

[0014] The drawbacks of this method are as follows: While flotation can process minerals with a particle size of nearly 10 micrometers, this is contingent upon a significant difference in the wettability (floatability) of the separated minerals and gangue surfaces, or a significant difference in surface wettability after the application of flotation reagents. When separating fine-grained ilmenite from gangue olivine and pyroxene, the small difference in surface wettability among the three types means that the increase in this difference is not significant even after adding flotation reagents. This results in the loss of fine-grained ilmenite in the tailings during ilmenite flotation in the Panzhihua area. This remains a key technical challenge in ilmenite flotation in the Panzhihua-Xichang region. Summary of the Invention

[0015] The technical problem to be solved by the present invention is to provide a surface hydrophobic coated heavy media flotation device and process that can effectively separate ilmenite from tailings.

[0016] The technical solution adopted by the present invention to solve its technical problem is: a surface hydrophobic coated heavy medium flotation device, including a flotation cell, wherein a concentrate outlet is provided at the lower end of the flotation cell, the inner bottom surface of the flotation cell is an inclined surface structure, and the inner bottom surface of the flotation cell is inclined towards the concentrate outlet.

[0017] The inclination angle of the bottom surface of the flotation cell in the above-mentioned device is 3 to 30°.

[0018] The surface hydrophobic coating heavy media flotation process includes the following steps:

[0019] S1. Grind the raw ore to obtain raw ore slurry;

[0020] S2. The rubber-coated heavy medium and the raw ore slurry are fed into any of the above-mentioned hydrophobic coated heavy medium flotation equipment in proportion.

[0021] S3. Stir vigorously and add kerosene during the stirring process and continue stirring. Then add pine oil and stir again. After aeration and flotation, separate the concentrate and tailings.

[0022] S4. Perform weak magnetic separation on the obtained concentrate and tailings to remove the heavy media mixed in the concentrate and tailings for reuse.

[0023] In the above process, in step S1, a ball mill is used to grind the raw ore, and the resulting raw ore slurry has a grinding fineness of -0.074 mm and a content of 65% to 75%.

[0024] In step S2 of the above process, the rubber thickness is 10–20 μm, and the heavy medium particle size is 0.038–0.074 mm.

[0025] In the above process, the ratio of the heavy medium with rubber coating to the raw ore slurry in step S2 is 1:9.

[0026] In the above process, the stirring speed in step S3 is 1500-2300 r / min.

[0027] In step S3 of the above process, 1000-2000 g / t of kerosene is added and stirred for 2-3 minutes, followed by 30-80 g / t of pine oil and stirring for 1-2 minutes.

[0028] In the above process, the time for aeration flotation in step S3 is 2 to 3 minutes.

[0029] In the above process, step S4 uses a drum magnetic separator with a magnetic field strength of 70-80 kA / m.

[0030] The beneficial effects of this invention are as follows: This solution designs a process and equipment that combines the advantages of heavy media beneficiation and flotation, which can effectively achieve the separation of fine-grained minerals. Furthermore, this solution is simple to operate, with a simple equipment structure, few moving parts, stable operation, and low energy consumption. It creatively combines heavy media beneficiation and flotation by simply modifying an existing flotation machine, achieving a heavy suspension with a high specific gravity and a relatively uniform distribution of heavy media. Moreover, the heavy media is easily recovered, with minimal loss during the beneficiation process. This is a beneficiation process and equipment with great development and application prospects. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the flotation equipment of the present invention.

[0032] Figure 2 This is a schematic diagram of the flow of various substances in the flotation process of this invention.

[0033] The following are marked in the diagram: 1. Pulley, 2. Stirring shaft, 3. Atmospheric air, 4. Stirring shaft sleeve, 5. Impeller, 6. Heavy medium with air bubbles adhering to its surface, 7. Flotation cell, 8. Feed port, 9. Float overflow port, 10. Concentrate port, 11. Heavy medium with rubber coating, 12. Heavy mineral, 13. Light mineral. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] like Figure 1 and Figure 2 As shown, the surface hydrophobic coated heavy media flotation device of the present invention includes a flotation cell 7, with a concentrate outlet 10 at the lower end of the flotation cell 7. The inner bottom surface of the flotation cell 7 is an inclined surface structure, and the inner bottom surface of the flotation cell 7 is inclined towards the concentrate outlet 10. Those skilled in the art will understand that existing flotation equipment mainly includes a pulley 1, a stirring shaft 2, a stirring shaft sleeve 4, an impeller 5, and a flotation cell 7. The pulley 1 drives the stirring shaft 2 and the impeller 5 to rotate within the flotation cell 7. The feed outlet 8 is located on one side of the upper end of the flotation cell 7, and the overflow outlet 9 is located on the other side, allowing the discharge of light minerals 13, i.e., tailings. The concentrate outlet 10 at the lower end of the flotation cell 7 allows the discharge of heavy minerals 12, i.e., concentrate. The flotation equipment in this scheme has been improved compared with the existing flotation machine. In order to facilitate the timely discharge of heavy media and heavy minerals 12 in the flotation machine, the inner bottom surface of the flotation cell 7 is preferably inclined, and the inner bottom surface of the flotation cell 7 is inclined to the concentrate outlet 10.

[0036] Preferably, the inclination angle of the bottom surface of the flotation cell 7 in the above-mentioned device is 3 to 30°. Those skilled in the art will understand that this preferred inclination angle of the bottom surface of the flotation cell 7 is 3 to 30° to prevent the accumulation of heavy minerals 12 and heavy media at the bottom of the flotation cell 7.

[0037] The surface hydrophobic coating heavy media flotation process includes the following steps:

[0038] S1. Grind the raw ore to obtain raw ore slurry;

[0039] S2. The rubber-coated heavy medium 11 and the raw ore slurry are fed into any of the above-mentioned hydrophobic coated heavy medium flotation equipment in proportion.

[0040] S3. Stir vigorously and add kerosene during the stirring process and continue stirring. Then add pine oil and stir again. After aeration and flotation, separate the concentrate and tailings.

[0041] S4. The obtained concentrate and tailings are subjected to weak magnetic separation to remove the heavy media mixed in the concentrate and tailings for reuse. Those skilled in the art will understand that this scheme uses fine-particle ferrosilicon or heavier media coated with rubber or other hydrophobic thin layers to prepare a suspension. Different heavy media are selected for heavy media beneficiation as needed. The rubber-coated heavy media can increase wear and can be recycled and reused. A small amount of flotation reagent can have a strong effect on the surface of rubber or other hydrophobic thin layers, so that the rubber-coated heavy media has stronger surface hydrophobicity under the action of flotation reagent, so it is aerophilic. Add a foaming agent and fill the sleeve 4 with atmospheric pressure air 3, so that a large number of fine-particle bubbles are generated in the slurry under the aeration effect. A large number of bubbles will adhere to the surface of the rubber-coated heavy media 11 to form surface-adhered bubble heavy media 6, which will then rise to the surface of the slurry. After a period of time, the foam breaks, and the heavy media falls from the surface of the slurry to the bottom of the separator and is carried back to the surface of the slurry by new foam. This achieves the effect of continuous circulation of the heavy medium within the separation tank. Therefore, the specific gravity of the heavy medium suspension remains relatively stable. A mixture of ground slurry and rubber-coated heavy medium 11 is fed into the flotation equipment according to a certain ratio (heavy medium mass content between 10% and 50%). After adding reagents, stirring, and aerating, the rubber-coated heavy medium 11 forms a uniform heavy suspension within the flotation machine. Useful minerals with a specific gravity greater than that of the heavy suspension settle to the bottom of the separator and are discharged as concentrate, while gangue minerals with a specific gravity less than that of the heavy suspension float and overflow. Based on prior calculations and experimental verification, heavy suspensions with different particle sizes and concentrations can be configured according to the specific gravity differences between gangue and minerals, achieving a higher separation specific gravity than ordinary heavy medium beneficiation, thus enabling heavy medium beneficiation of metallic minerals. In this sorting process, it is necessary to select a mineral processing reagent that only interacts with rubber-like surfaces and does not interact with the two types of mineral particles to be sorted. In practice, kerosene combined with pine oil can be used to sort almost all colored minerals and gangue minerals.

[0042] Preferably, in step S1 of the above process, a ball mill is used to grind the raw ore, and the resulting raw ore slurry has a grinding fineness of -0.074 mm and a content of 65% to 75%. Those skilled in the art will understand that, in order to ensure the particle size and beneficiation quality of the raw ore slurry, this process preferably uses a ball mill to grind the raw ore, and further specifies that the resulting raw ore slurry has a grinding fineness of -0.074 mm and a content of 65% to 75%.

[0043] Preferably, in step S2 of the above process, the rubber thickness is 10-20 μm and the heavy medium particle size is 0.038-0.074 mm. Those skilled in the art will understand that, in order to ensure the quality of the heavy medium and the results of mineral processing, this process preferably uses a rubber thickness of 10-20 μm and a heavy medium particle size of 0.038-0.074 mm.

[0044] Preferably, in step S2 of the above process, the ratio of the rubber-coated heavy medium 11 to the raw ore slurry is 1:9 to 1:1. Those skilled in the art will understand that this process only preferably uses a ratio of the rubber-coated heavy medium 11 to the raw ore slurry, specifically a ratio of 1:9 to 1:1.

[0045] Preferably, the stirring speed in step S3 of the above process is 1500–2300 r / min. Those skilled in the art will understand that, in order to ensure uniform mixing of the heavy medium and the raw ore slurry, a stirring speed of 1500–2300 r / min is preferred.

[0046] Preferably, in step S3 of the above process, 1000-2000 g / t of kerosene is added and stirred for 2-3 minutes, followed by 30-80 g / t of pine oil and stirring for 1-2 minutes. Those skilled in the art will understand that, in order to prepare a suitable heavy liquid, this process preferably involves adding 1000-2000 g / t of kerosene and stirring for 2-3 minutes, followed by 30-80 g / t of pine oil and stirring for 1-2 minutes.

[0047] Preferably, the aeration flotation time in step S3 of the above process is 2 to 3 minutes. Those skilled in the art will understand that, in order to ensure flotation quality, the aeration flotation time is preferably 2 to 3 minutes in this process.

[0048] Preferably, in step S4 of the above process, a drum magnetic separator is used, and the magnetic field strength is 70-80 kA / m. Those skilled in the art will understand that after heavy media separation, the overflow and settled heavy minerals 12 will inevitably contain a large number of heavy media particles coated with rubber or other hydrophobic thin layers. This process preferably uses a drum magnetic separator with a magnetic field strength of 70-80 kA / m. When using ferromagnetic metal particles (iron powder, manganese powder, etc.) as the heavy media, a very low-cost weak magnetic separator can be used for simple one or two stages of weak magnetic separation to achieve a recovery rate of approximately 99.8% or more, allowing for reuse.

[0049] Example 1

[0050] The tailings (i.e., raw ilmenite ore sample) from the dry iron beneficiation of vanadium-titanium magnetite in a certain area of ​​Panzhihua contains 29.67% TiO2, and the main gangue minerals are silicate minerals such as pyroxene. This process is used to separate the ilmenite. The raw ilmenite ore is ground using a ball mill to a fineness of -0.074 mm with a content of 65%–75%, thus obtaining a raw ore slurry. A heavy medium 11 with a rubber-coated surface (rubber thickness 10–20 μm, heavy medium particle size between 0.038 and 0.074 mm) and the raw ore slurry are fed into the flotation equipment of this invention at a ratio of 1:9. Strong stirring is performed at a speed of 1500–2300 r / min, and kerosene 1000–2000 g / t is added during stirring, with stirring continued for 2–3 min. Then, pine oil 30–80 g / t is added, stirring for 1 min, followed by aeration and flotation for 3 min. Finally, separation is performed to obtain concentrate and tailings. The obtained concentrate and tailings were subjected to weak magnetic separation using a drum magnetic separator with a magnetic field strength of 80 kA / m. Heavy media particles entrained in the concentrate and tailings were separated and combined as regenerated heavy media for reuse, with a heavy media recovery rate greater than 99.8%. The titanium concentrate after heavy media removal contained 47.41% TiO2, and the recovery rate of this operation was 78.99%.

[0051] Comparative Example 1

[0052] The tailings (i.e., raw ilmenite ore samples) from the dry iron ore beneficiation of vanadium-titanium magnetite in a certain area of ​​Panzhihua contain 9.67% TiO2. The main gangue minerals are silicate minerals such as pyroxene. Since pyroxene has similar magnetic and flotation behavior to ilmenite, the existing high-gradient pre-enrichment-desulfurization-roughing-cleaning-scavenging process can yield a TiO2 grade of 45.64% and an operating recovery rate of 68.28%, with a titanium concentrate recovery rate of 46.75% for iron ore tailings. It can be seen that the existing process is relatively complex.

[0053] As can be seen from Example 1 and Comparative Example 1, the TiO2 grade and recovery rate of the ilmenite concentrate obtained in this Example 1 are significantly improved. At the same time, this process is short and the flotation time is also reduced, thus decreasing production costs. This demonstrates that the process and equipment provided by this invention have the advantages of short process, easy operation, stable indicators, and low energy consumption.

[0054] Example 2

[0055] The iron tailings from the vanadium-titanium magnetite ore beneficiation process in a certain area of ​​Panzhihua contain 7.88% TiO2. This process and equipment are used to separate the ilmenite. The raw ilmenite ore is ground using a ball mill to a fineness of -0.074 mm with a content of 65%–75%, thus obtaining a raw ore slurry. Rubber-coated iron metal spherical particles (rubber thickness 10–20 μm, heavy medium particle size between 0.038 and 0.074 mm) and the raw ore slurry are fed into the flotation equipment of this invention at a ratio of 1.5:8.5; 1300-21 The mixture is vigorously stirred at 00 r / min, with kerosene 800-1800 g / t added during stirring and stirring for 2-3 minutes. Then, pine oil 30-80 g / t is added and stirred for 1 minute. Aeration and flotation are then performed for 3 minutes, followed by separation to obtain concentrate and tailings. The concentrate and tailings are then subjected to weak magnetic separation using a drum magnetic separator with a magnetic field strength of 82 kA / m. Heavy media particles entrained in the concentrate and tailings are magnetically separated and combined as regenerated heavy media for reuse, with a heavy media recovery rate greater than 99.6%. The titanium concentrate after heavy media removal has a TiO2 content of 47.89% and an operational recovery rate of 78.09%.

[0056] Comparative Example 2

[0057] In a certain area of ​​Panzhihua, the iron tailings from the vanadium-titanium magnetite ore beneficiation process contained 7.88% TiO2. By using a combined process of strong magnetic pre-selection and flotation (two roughers, four cleaners, and two scavengers), a titanium concentrate containing 48.20% TiO2 and a flotation recovery rate of 75.65% was obtained. The titanium beneficiation results are quite ideal, but it can be seen that the existing process is lengthy and complex.

[0058] As shown in Example 2 and Comparative Example 2, the TiO2 grade of the ilmenite concentrate obtained in Example 2 is similar, but the recovery rate is significantly improved. Most importantly, this process is short and requires less flotation time, reducing production costs. This demonstrates that the process and equipment provided by this invention have the advantages of short process, ease of operation, stable indicators, and low energy consumption.

Claims

1. A surface-hydrophobic coated heavy media flotation process, characterized in that... Includes the following steps: S1. Grind the raw ilmenite ore to obtain a raw ore slurry; S2. The heavy medium (11) with rubber coating and the raw ore slurry are fed into the surface hydrophobic coated heavy medium flotation equipment in proportion. The equipment includes a flotation cell (7), and a concentrate inlet (10) is provided at the lower end of the flotation cell (7). The inner bottom surface of the flotation cell (7) is an inclined surface structure, and the inner bottom surface of the flotation cell (7) is inclined to the concentrate inlet (10). The inclination angle of the inner bottom surface of the flotation cell (7) is 3 to 30°. S3. Vigorously stir and add kerosene during the stirring process, then add No. 2 oil and stir again. After aeration and flotation, separate the concentrate and tailings. S4. Perform weak magnetic separation on the obtained concentrate and tailings respectively to remove the heavy media mixed in the concentrate and tailings for reuse; In step S2, the rubber thickness is 10-20 μm and the particle size of the heavy medium is 0.038-0.074 mm; the ratio of the heavy medium (11) with rubber coating to the raw ore slurry is 1:9-1:

1.

2. The surface hydrophobic coating heavy media flotation process as described in claim 1, characterized in that: In step S1, a ball mill is used to grind the raw ore, and the resulting raw ore slurry has a grinding fineness of -0.074 mm and a content of 65% to 75%.

3. The surface hydrophobic coating heavy media flotation process as described in claim 1, characterized in that: The stirring speed in step S3 is 1500-2300 r / min.

4. The surface hydrophobic coating heavy media flotation process as described in claim 1, characterized in that: In step S3, add 1000-2000 g / t of kerosene and continue stirring for 2-3 minutes, then add 30-80 g / t of pine oil and stir for 1-2 minutes.

5. The surface hydrophobic coating heavy media flotation process as described in claim 1, characterized in that: The time for aeration flotation in step S3 is 2 to 3 minutes.

6. The surface hydrophobic coating heavy media flotation process as described in claim 1, characterized in that: In step S4, a drum magnetic separator is used, and the magnetic field strength is 70-80 kA / m.

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