A process for recovering fine particles of wernerite based on shear flocculation-carrier flotation

Abstract

This application relates to the field of refractory mineral processing technology, specifically to a process for recovering fine-particle beryllium based on shear flocculation-carrier flotation. The process includes the following steps: adding a dispersant to a slurry containing fine-particle beryllium and stirring and scrubbing to obtain a dispersed fine-particle slurry; adjusting the pH to 9.0-10.0; then adding a gangue inhibitor and a beryllium collector for hydrophobic modification; adding an auxiliary collector to the modified slurry and shearing and stirring to obtain a slurry containing hydrophobic flocs; adding coarse-particle beryllium concentrate as a carrier for slurry conditioning to obtain a mineralized slurry; finally, performing aerated flotation on the mineralized slurry and skimming off the foam to obtain the beryllium concentrate. This application, through a coupling mechanism of "dispersion-hydrophobicity-shear-carrier," increases the apparent particle size and momentum of fine-particle beryllium, solving the problems of low collision probability and difficult recovery of fine-particle beryllium with air bubbles, and improving the recovery rate of this resource.

Description

Technical Field

[0001] This application relates to the field of refractory mineral processing technology, specifically to a process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation. Background Technology

[0002] In nature, barite (BaCO3) often occurs in close association with minerals such as barite (BaSO4) and calcite (CaCO3), forming ores with a complex quaternary system of calcium, barium, carbonate, and sulfate. Existing beneficiation technologies inevitably generate large amounts of extremely fine slime during crushing, grinding, and classification processes, typically with a particle size of -0.038 mm. Conventional flotation processes struggle to effectively recover this fine-grained barite.

[0003] Specifically, gravity separation equipment such as spiral sluices has extremely low separation efficiency for particles in the -0.038 mm size range. This results in the frequent discarding of this fine-grained heavy metal resource as tailings, leading to resource waste. Furthermore, the extremely small mass and insufficient momentum of this fine-grained heavy metal make it difficult to break through the hydration film on the bubble surface during flotation, resulting in very low particle-bubble collision and adhesion efficiency. In addition, the large specific surface area of ​​this fine-grained heavy metal causes it to not only adsorb large amounts of collectors during flotation but also produce non-selective slime capping, leading to a decrease in concentrate grade. Currently, there is no effective recycling and beneficiation technology for this fine-grained heavy metal in this field.

[0004] Therefore, it is necessary to develop a process for the recovery of fine-particle barium toxicite in order to achieve the effective recycling of this difficult-to-select barium resource. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a fine-particle heavy rock recovery process based on shear flocculation-carrier flotation. Through the coupling mechanism of "dispersion-hydrophobicity-shear-carrier", the apparent particle size and momentum of fine-particle heavy rock are increased, solving the problems of low collision probability and difficult recovery of fine-particle heavy rock with bubbles, and improving the recovery rate of this resource.

[0006] The objective of this application is achieved through the following technical solution: This application provides a process for recovering fine-particle heavy rock based on shear flocculation-carrier flotation, including the following steps: S1. Pretreatment of fine-particle mineral slurry dispersion: Add dispersant to mineral slurry containing fine-particle barite and stir and scrub to obtain dispersed fine-particle mineral slurry; S2. Surface hydrophobic modification: The pH of the dispersed fine-particle slurry is adjusted to 9.0~10.0 using a pH adjuster, and then gangue inhibitor and barite collector are added to carry out hydrophobic modification to obtain modified slurry; S3. High-energy shear flocculation: Add an auxiliary collector to the modified slurry and shear stir to obtain a slurry containing hydrophobic flocs; S4. Adding a carrier and mineralization: Add coarse-grained barite concentrate as a carrier to the slurry containing hydrophobic flocs to adjust the slurry and obtain a mineralized slurry; S5. Flotation separation: The mineralized slurry is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate.

[0007] In the above technical solutions, the pretreatment of fine-particle mineral slurry dispersion can eliminate non-selective agglomeration between fine-particle mineral mud, remove the silicate fine mud covering the surface of the barite, and expose the fresh surface of the fine-particle barite particles. During surface hydrophobic modification, the addition of gangue inhibitors can make the surface of gangue minerals hydrophilic, preventing them from binding with the added barite collector. The addition of barite collectors can utilize the adsorption effect of the collectors on the mineral surface to coat the surface of the barite particles with a hydrophobic film. High-energy shear flocculation can enable the fine-particle barite to overcome the electrostatic repulsion between particles, increasing the collision frequency. At the same time, the bridging effect of non-polar oil droplets between hydrophobic particles can be used to bind the fine-particle barite into larger, more compact hydrophobic flocs. The addition of a carrier and mineralization can utilize the larger momentum and stronger hydrophobicity of the coarse-particle carrier to capture and adsorb the hydrophobic flocs in the slurry, forming an aggregate of coarse particles carrying fine particles. Finally, the mineralized slurry is subjected to aeration flotation, which allows the carrier aggregate to float to the surface with the air bubbles and become concentrate, while the unaggregated fine gangue particles remain in the tank as tailings.

[0008] Furthermore, in S1, the fine-grained barite includes barite with a particle size distribution in the range of -0.038 mm.

[0009] Furthermore, in S1, the concentration of the slurry is 18% to 20%.

[0010] Furthermore, in S1, the dispersant includes at least one of sodium hexametaphosphate, water glass, and sodium polyacrylate.

[0011] Furthermore, in S1, the amount of the dispersant used is 150~200 g / t based on the dry solids weight in the slurry.

[0012] Furthermore, in S2, the pH adjuster includes one of sodium carbonate and sodium hydroxide.

[0013] Furthermore, in S2, the gangue inhibitor includes at least one of water glass and modified starch.

[0014] Furthermore, in S2, the barite collector includes a fatty acid collector.

[0015] Furthermore, in S2, the amount of gangue inhibitor used is 200~1000 g / t based on the dry solids weight in the slurry.

[0016] Furthermore, in S2, the amount of the barite collector used is 300~600 g / t based on the dry solids weight in the slurry.

[0017] In some embodiments, the fatty acid collector includes at least one of sodium oleate, oxidized paraffin soap, and tal oil.

[0018] Furthermore, in S3, the auxiliary collector comprises a non-polar oil.

[0019] In some embodiments, the non-polar oil includes one of kerosene, diesel oil, and emulsified kerosene.

[0020] In some embodiments, the amount of non-polar oil used is 50~150 g / t.

[0021] Furthermore, in S4, the coarse-grained barite concentrate includes barite concentrate with a particle size distribution of +0.038 and a BaCO3 grade of 72% to 78%.

[0022] Furthermore, the mass ratio of the carrier to the slurry containing hydrophobic flocs is (1~2.5):1.

[0023] Furthermore, in S1, the stirring and scrubbing speed is 1200~1800 r / min, and the stirring and scrubbing time is 2~5 min.

[0024] Furthermore, in S2, the hydrophobic modification time is 2 to 8 minutes.

[0025] Furthermore, in S3, the Reynolds number Re of the shear stirring is greater than 10. 5 The shearing and stirring speed is 1850~2550 r / min, and the shearing and stirring time is 8~15 min.

[0026] The beneficial effects of this application are: 1. This application targets fine-particle toxic heavy stone, and transforms the original 5~20 μm particles into large flocs of 50~100 μm through shear flocculation, so that it exhibits coarse particle behavior in hydrodynamics, and the probability of collision and adhesion with bubbles is greatly improved.

[0027] 2. This application innovatively uses coarse-grained barite concentrate as a carrier to avoid introducing exogenous impurities, so that the flotation froth product does not need to undergo carrier removal and can be directly used as the final concentrate.

[0028] 3. The non-polar oil used in this application is much cheaper than fatty acid collectors. By using inexpensive oils to assist in granulation, not only is the amount of collector used significantly reduced, but costs are also successfully saved.

[0029] 4. This application successfully increased the recovery rate of fine-grained barite with a particle size of -0.038 mm from 40%~50% in conventional processes to over 80%, significantly improving the utilization rate of this mineral resource. Attached Figure Description

[0030] Figure 1 This is a process flow diagram for the recovery of fine-particle heavy metals based on shear flocculation-carrier flotation in this application; Figure 2 This is a schematic diagram illustrating the mechanism of shear flocculation and carrier adsorption when recovering fine-particle heavy rock based on shear flocculation-carrier flotation in this application. Detailed Implementation

[0031] The technical solution of this application is described in further detail below with reference to the accompanying drawings, but the scope of protection of this invention is not limited to the following description. Example 1

[0032] The fine-grained barite in this embodiment is derived from the overflow slime of a heavy media hydrocyclone separation process for a barium carbonate ore. Its particle size of −0.038 mm accounts for over 95%, and the main gangue minerals are calcite and barite.

[0033] The following steps are used to recover fine-particle heavy minerals: S1. Pretreatment of fine-particle mineral slurry dispersion: The concentration of the mineral slurry containing fine-particle barite was adjusted to 20% using tap water. Then, sodium hexametaphosphate was added as a dispersant at a dosage of 200 g / t based on the dry solids weight of the slurry. The slurry was stirred and scrubbed at a speed of 1200 r / min for 8 min to eliminate non-selective agglomeration in the fine mineral mud, and the dispersed fine-particle mineral slurry was obtained. S2. Surface hydrophobic modification: Sodium carbonate was used as a pH adjuster to adjust the pH of the dispersed fine-particle slurry to 9.5. Then, water glass was added at a dosage of 1000 g / t as gangue inhibitor and sodium oleate was added at a dosage of 300 g / t as barite collector, based on the dry solids weight of the slurry. The mixture was stirred for 3 min for hydrophobic modification to obtain the modified slurry. S3. High-energy shear flocculation: Based on the dry solids weight of the slurry, kerosene is added to the modified slurry at a dosage of 100 g / t as an auxiliary collector. The stirring device is started to ensure that the Reynolds number Re > 10. 5Under the condition of stirring at 2200 r / min for 10 min, shear stirring is performed so that the fine particles form visible hydrophobic flocs under the binding effect of the oil film, and a mineral slurry containing hydrophobic flocs is obtained. S4. Adding a carrier and mineralization: Select the rougher concentrate produced by flotation (the part after hydraulic classification to remove -0.02 mm fine mud, with a main particle size of +0.038 mm and a BaCO3 grade of 72%) as a carrier and add it to the slurry containing hydrophobic flocs. The amount of carrier added is 1.5 times the dry weight of the fine feed ore in the slurry containing fine-grained barite. Adjust the stirring speed to 850 r / min and perform slurry conditioning for 2 min to allow the flocs to be adsorbed on the surface of the carrier, thus obtaining the mineralized slurry. S5. Flotation separation: The mineralized slurry is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate. Example 2

[0034] In this embodiment, the fine-grained barite was sourced from overflow slime from a barite gravity separation operation, with a -0.038 mm particle size content exceeding 90%.

[0035] The following steps are used to recover fine-particle heavy minerals: S1. Pretreatment of fine-particle mineral slurry dispersion: The concentration of the mineral slurry containing fine-particle barite was adjusted to 18% using tap water. Then, water glass was added as a dispersant at a dosage of 200 g / t based on the dry solids weight of the slurry. The slurry was stirred and scrubbed at a speed of 1500 r / min for 5 min to eliminate non-selective agglomeration in the fine mineral mud, and the dispersed fine-particle mineral slurry was obtained. S2. Surface hydrophobic modification: Sodium hydroxide was used as a pH adjuster to adjust the pH of the dispersed fine-particle slurry to 9.0. Then, based on the dry solids weight in the slurry, modified starch was added at a dosage of 200 g / t as gangue inhibitor and oxidized paraffin soap was added at a dosage of 350 g / t as barite collector. The mixture was stirred for 3 min for hydrophobic modification to obtain the modified slurry. S3. High-energy shear flocculation: Based on the dry solids weight of the slurry, diesel oil is added to the modified slurry at a dosage of 120 g / t as an auxiliary collector. The stirring device is started to ensure that the Reynolds number Re > 10. 5 Under the condition of stirring at 1850 r / min for 15 min, shear stirring is performed so that the fine particles form visible hydrophobic flocs under the adhesion of the oil film, and a mineral slurry containing hydrophobic flocs is obtained. S4. Adding a carrier and mineralization: Select the rougher concentrate produced by flotation (the part after hydraulic classification to remove -0.01 mm fine mud, with a main particle size of +0.38 mm and a BaCO3 grade of 72%) as a carrier and add it to the slurry containing hydrophobic flocs. The amount of carrier added is the same as the dry weight of the fine feed in the slurry containing fine-grained barite. Adjust the stirring speed to 850 r / min and perform slurry conditioning for 2 min to allow the flocs to be adsorbed on the carrier surface, thus obtaining the mineralized slurry. S5. Flotation separation: The mineralized slurry is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate. Example 3

[0036] The source of the fine-grained toxic barite in this embodiment is the overflow slime from a toxic barite gravity separation operation. The overflow contains 60% of the extremely fine mineral sample with a content of -0.01 mm.

[0037] The following steps are used to recover fine-particle heavy minerals: S1. Pretreatment of fine-particle mineral slurry dispersion: The concentration of the mineral slurry containing fine-particle barite was adjusted to 20% using tap water. Then, sodium polyacrylate was added as a dispersant at a dosage of 80 g / t based on the dry solids weight of the slurry. The mixture was stirred and scrubbed at 1800 r / min for 2 min to eliminate non-selective agglomeration in the fine mineral mud, and the dispersed fine-particle mineral slurry was obtained. S2. Surface hydrophobic modification: Sodium carbonate was used as a pH adjuster to adjust the pH of the dispersed fine-particle slurry to 9.8. Then, water glass was added at a dosage of 1000 g / t as gangue inhibitor and tar oil was added at a dosage of 600 g / t as barite collector, based on the dry solids weight of the slurry. The mixture was stirred for 3 min for hydrophobic modification to obtain the modified slurry. S3. High-energy shear flocculation: Based on the dry solids weight of the slurry, emulsified kerosene is added to the modified slurry at a dosage of 150 g / t as an auxiliary collector. At this point, the emulsified oil droplets are smaller and more easily capture extremely fine particles. The stirring device is started to ensure that the Reynolds number Re > 10. 5 Under the condition of stirring at 2550 r / min for 8 min, shear stirring is performed so that the fine particles form visible hydrophobic flocs under the adhesion of the oil film, and a mineral slurry containing hydrophobic flocs is obtained. S4. Adding a carrier and mineralization: Select the rougher concentrate produced by the main process flotation of the plant (the portion after hydraulic classification to remove -0.01 mm fine mud, with a main particle size of +0.038 mm and a BaCO3 grade of 72%) as a carrier and add it to the slurry containing hydrophobic flocs. The amount of carrier added is 2.5 times the dry weight of the fine feed ore in the slurry containing fine-grained barite. Adjust the stirring speed to 850 r / min and perform slurry conditioning for 2 minutes to allow the flocs to be adsorbed on the carrier surface, thus obtaining the mineralized slurry. S5. Flotation separation: The mineralized slurry is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate.

[0038] Comparative Example 1 This comparative example demonstrates a process for recovering finely granulated heavy metals, referencing Example 1. The difference from Example 1 is the absence of a shear flocculation step and the absence of carrier addition, in order to simulate existing direct flotation processes. The specific steps are as follows: S1. Pretreatment of fine-particle mineral slurry dispersion: The concentration of the mineral slurry containing fine-particle barite was adjusted to 20% using tap water. Then, sodium hexametaphosphate was added as a dispersant at a dosage of 200 g / t based on the dry solids weight of the slurry. The mixture was stirred and scrubbed at 1200 r / min for 3 min to eliminate non-selective agglomeration in the fine mineral mud, and the dispersed fine-particle mineral slurry was obtained. S2. Surface hydrophobic modification: Sodium carbonate was used as a pH adjuster to adjust the pH of the dispersed fine-particle slurry to 9.5. Then, water glass was added at a dosage of 1000 g / t as gangue inhibitor and sodium oleate was added at a dosage of 300 g / t as barite collector, based on the dry solids weight of the slurry. The mixture was stirred for 3 min for hydrophobic modification to obtain the modified slurry. S3. Conventional stirring: Start the stirring device and stir at 850 r / min for 10 min to obtain the stirred modified slurry; S4. Flotation separation: The modified slurry after stirring is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate.

[0039] Comparative Example 2 The comparative example describes the process for recovering finely granulated barite, referring to Example 1. The difference from Example 1 is that no carrier was added, in order to verify the necessity of the carrier. The specific steps are as follows: S1. Pretreatment of fine-particle mineral slurry dispersion: The concentration of the mineral slurry containing fine-particle barite was adjusted to 20% using tap water. Then, sodium hexametaphosphate was added as a dispersant at a dosage of 200 g / t based on the dry solids weight of the slurry. The mixture was stirred and scrubbed at 1200 r / min for 3 min to eliminate non-selective agglomeration in the fine mineral mud, and the dispersed fine-particle mineral slurry was obtained. S2. Surface hydrophobic modification: Sodium carbonate was used as a pH adjuster to adjust the pH of the dispersed fine-particle slurry to 9.5. Then, water glass was added at a dosage of 1000 g / t as gangue inhibitor and sodium oleate was added at a dosage of 300 g / t as barite collector, based on the dry solids weight of the slurry. The mixture was stirred for 3 min for hydrophobic modification to obtain the modified slurry. S3. High-energy shear flocculation: Based on the dry solids weight in the slurry, kerosene is added to the modified slurry at a dosage of 100 g / t as an auxiliary collector. The stirring device is started and the slurry is stirred at a speed of 2200 r / min for 10 min for shear stirring, so that the fine particles form visible hydrophobic flocs under the adhesion of the oil film, and a slurry containing hydrophobic flocs is obtained. S54 Flotation separation: The slurry containing hydrophobic flocs is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate.

[0040] Experiment Example 1: Verification of Mineral Processing Indicators After calculating the concentrate recovery rate and concentrate grade of the barite concentrate obtained in Examples 1-3 and Comparative Examples 1-2, the effects of non-polar oil dosage, shear stirring speed, and carrier ratio on concentrate recovery rate and concentrate grade were statistically analyzed. The results are shown in Table 1.

[0041] Table 1 Summary of Mineral Processing Indicators The results show that, comparing the effects of Examples 1 and 2, even with a reduced carrier dosage, a high recovery level can still be maintained after diesel shear flocculation. Comparing the effects of Examples 1 and 2, under extremely difficult beneficiation conditions, the operational recovery rate of fine-grained barite can still be maintained at 79.42%, and the concentrate grade at 69.57%, proving that this application still has good capture ability for extremely fine particles. Comparing the effects of Example 1 and Comparative Example 1, the direct flotation process results in lower momentum due to a thin, loose froth layer and the inclusion of a large amount of slime. The fine particles could not effectively adhere to the bubbles, and most of them were lost with the tailings. At the same time, because they did not form large flocs with a large specific surface area, a large amount of reagents were consumed but no effect was achieved. In the end, the recovery effect of fine-particle heavy rock was generally poor. From the comparison of the effects of Example 1 and Comparative Example 2, although flocs could be formed by abandoning the use of coarse-particle carriers, the simple hydrophobic floc structure was relatively loose and easily broke in the turbulent environment during the bubble floating process. At the same time, due to the lack of the effect of coarse-particle carriers, the recovery rate was difficult to reach a high level. This reflects the indispensability of the synergistic effect of shear flocculation and carrier flotation in this application.

[0042] The above description is merely a preferred embodiment of this application. It should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this invention should be within the protection scope of the appended claims.

Claims

1. A process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation, characterized in that, Includes the following steps: S1. Pretreatment of fine-particle mineral slurry dispersion: Add dispersant to mineral slurry containing fine-particle barite and stir and scrub to obtain dispersed fine-particle mineral slurry; S2. Surface hydrophobic modification: The pH of the dispersed fine-particle slurry is adjusted to 9.0~10.0 using a pH adjuster, and then gangue inhibitor and barite collector are added to carry out hydrophobic modification to obtain modified slurry; S3. High-energy shear flocculation: Add an auxiliary collector to the modified slurry and shear stir to obtain a slurry containing hydrophobic flocs; S4. Adding a carrier and mineralization: Add coarse-grained barite concentrate as a carrier to the slurry containing hydrophobic flocs to adjust the slurry and obtain a mineralized slurry; S5. Flotation separation: The mineralized slurry is subjected to aerated flotation, and the froth is scraped off to obtain the barite concentrate.

2. The process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation according to claim 1, characterized in that, In S1, the fine-grained barite includes barite with a particle size distribution in the range of -0.038 mm. And / or, in S1, the concentration of the slurry is 18%~20%; And / or, in S1, the dispersant comprises at least one of sodium hexametaphosphate, water glass, and sodium polyacrylate; And / or, in S1, the amount of the dispersant is 150~200 g / t based on the dry solids weight in the slurry.

3. The process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation according to claim 1, characterized in that, In S2, the pH adjuster includes one of sodium carbonate and sodium hydroxide; And / or, in S2, the gangue inhibitor comprises at least one of water glass and modified starch; And / or, in S2, the barite collector includes a fatty acid collector; And / or, in S2, the amount of gangue inhibitor used is 200~1000 g / t based on the dry solids weight in the slurry; And / or, in S2, the amount of the barite collector is 300~600 g / t based on the dry solids weight in the slurry.

4. The process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation according to claim 3, characterized in that, The fatty acid collectors include at least one of sodium oleate, oxidized paraffin soap, and tal oil.

5. The process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation according to claim 1, characterized in that, In S3, the auxiliary collector comprises a non-polar oil.

6. The process for recovering fine-particle toxic barite based on shear flocculation-carrier flotation according to claim 5, characterized in that, The non-polar oil includes one of kerosene, diesel oil, and emulsified kerosene; And / or, the amount of the non-polar oil used is 100~150 g / t.

7. The process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation according to claim 1, characterized in that, In S4, the coarse-grained barite concentrate includes barite concentrate with a particle size distribution of +0.038 and a BaCO3 grade of 72% to 78%. And / or, the mass ratio of the carrier to the slurry containing hydrophobic flocs is (1~2.5):

1.

8. The process for recovering fine-particle toxic heavy rock based on shear flocculation-carrier flotation according to claim 1, characterized in that, In S1, the stirring and scrubbing speed is 1200~1800 r / min, and the stirring and scrubbing time is 2~5 min; And / or, in S2, the hydrophobic modification time is 2~8 min; And / or, in S3, the Reynolds number Re of the shear stirring is >10. 5 The shearing and stirring speed is 1850~2550 r / min, and the shearing and stirring time is 8~15 min.

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