Beneficiation method for recovering barite from tailings

Abstract

The invention discloses a beneficiation method for recovering barite from tailings, and belongs to the technical field of mineral processing. According to the method, through the technological process of magnetic separation and gravity concentration pre-enrichment, flotation concentration and roasting acid leaching quality improvement, heavy magnetic suspension physical beneficiation, high-temperature roasting and chemical leaching are organically combined, meanwhile, a shaking table technology is optimized, ore grinding is conducted through a stirring mill twice, and BaSO4 grade gt is prepared from low-grade tailings; and 98% of barite concentrate. The technological process provided by the invention is reasonable in structure, high in separation efficiency, small in environmental pollution and easy to realize industrial production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mineral processing, and particularly relates to a beneficiation method for recovering barite from tailings. BACKGROUND

[0002] Barite (BaSO4) is a non-metallic mineral with important strategic value, which is widely used in oil and gas drilling weighting agents, chemical industry, fillers, paint, medicine and other fields. The global and domestic market demand for high-quality barite is growing, especially high specific gravity (>4.2 g / cm 3 Although China is a large country of barite resources, with the exhaustion of high-quality and easy-to-select barite resources, recovering barite from tailings and realizing efficient recycling of resources have become a key way to ensure resource supply, reduce environmental pollution and improve the economic benefits of mines.

[0003] A large amount of tailings still contain considerable barite resources, but these resources are generally characterized by fine dissemination size, complex mineral composition and low grade. At present, the main methods of barite separation include magnetic separation, gravity separation and flotation. Due to the complex occurrence of barite in tailings, combined separation processes such as magnetic separation-flotation combination, flotation-gravity separation combination are often needed. Chinese patent CN119588506A discloses a method for recovering barite from heat-treated drilling waste, which adopts a wet screening-magnetic separation-flotation (one rough three fine four sweep) process to obtain barite concentrate with a grade of more than 88%. However, this process only uses magnetic separation for pre-concentration and impurity removal, resulting in a long subsequent flotation process and increasing production costs. Chinese patent CN118950239A discloses a method for recovering barite from oil-based drilling cuttings, which adopts a roasting-flotation-strong magnetic separation combined process to obtain a concentrate with a barite content of 91.30%. However, this process uses the sequence of flotation followed by magnetic separation, which increases the flotation treatment capacity and reagent consumption.

[0004] In summary, the existing barite recovery technologies, especially the combined processes for tailings, generally have the problems of complex process flow, poor process adaptability, high energy consumption and reagent cost, and low concentrate quality. Therefore, it is urgent to develop an efficient, economic, environmentally friendly and adaptable method for efficiently recovering barite from tailings and deep purification to realize the high-value application of barite concentrate. SUMMARY

[0005] To solve the above problems, the application provides a beneficiation method for recovering barite from tailings.

[0006] To achieve the above object, the application adopts the technical scheme of:

[0007] A beneficiation method for recovering barite from tailings, which is specifically performed according to the following steps:

[0008] Step 1: removing iron by magnetic separation

[0009] The tailings containing barite are fed into a low-intensity magnetic separator to obtain low-intensity magnetic concentrate and low-intensity magnetic tailings; the low-intensity magnetic tailings are subjected to high-intensity magnetic separation to obtain high-intensity magnetic concentrate and high-intensity magnetic tailings; and the low-intensity magnetic concentrate and the high-intensity magnetic concentrate are mixed to obtain iron rough concentrate;

[0010] Step 2: heavy separation by shaking table

[0011] The process flow of the heavy separation by shaking table is one roughing, one scavenging and one cleaning: the high-intensity magnetic tailings are subjected to roughing by a shaking table to obtain shaking table roughing concentrate, shaking table roughing middlings and shaking table roughing tailings; the shaking table roughing middlings are subjected to scavenging by the shaking table to obtain shaking table scavenging concentrate and shaking table scavenging tailings, and the shaking table scavenging concentrate is subjected to cleaning by the shaking table to obtain shaking table cleaning concentrate and shaking table cleaning tailings; wherein the shaking table roughing concentrate and the shaking table cleaning concentrate are combined to obtain shaking table heavy separation concentrate, and the shaking table roughing tailings, the shaking table scavenging tailings and the shaking table cleaning tailings are combined to obtain shaking table tailings;

[0012] Step 3: cleaning by flotation

[0013] The shaking table heavy separation concentrate is ground in a stirring mill and then subjected to flotation separation, and the flotation process is one roughing, two cleanings and one scavenging: in the roughing stage, sodium carbonate as a pH adjusting agent, sodium silicate as an inhibitor, citric acid and sodium oleate as a collector are sequentially added, and air is injected to scrape bubbles to obtain roughing concentrate and roughing tailings; the roughing concentrate is subjected to one-stage cleaning, and sodium silicate is added in the one-stage cleaning stage, and air is injected to scrape bubbles to obtain one-stage cleaning concentrate and one-stage cleaning tailings; the one-stage cleaning concentrate is subjected to two-stage cleaning, and air is directly injected to scrape bubbles without adding any reagent to obtain barite rough concentrate and two-stage cleaning tailings; the roughing tailings are subjected to scavenging, and sodium oleate is added in the scavenging stage, and air is injected to scrape bubbles to obtain scavenging concentrate and tailings; the one-stage cleaning tailings, the two-stage cleaning tailings and the scavenging concentrate are returned to the previous operation respectively;

[0014] Step 4: roasting and acid leaching

[0015] The barite rough concentrate is ground in a stirring mill, and the ground product is sequentially subjected to high-temperature roasting, acid leaching and stirring, and then filtered, washed to neutral with distilled water and dried to obtain high-quality barite.

[0016] Further, the barite-containing tailings in step 1 have a particle size of less than or equal to 2 mm, the magnetic field strength of the low-intensity magnetic separator is 1000 Oe to 1500 Oe, and the background field strength of the high-intensity magnetic separator is 3500 Gs to 4500 Gs.

[0017] Further, the shaking table in step 2 has a stroke of 240 times / min to 280 times / min and an inclination of 2° to 2.5°.

[0018] Further, the grinding equipment in step 3 is a ceramic stirring mill, and the product particle size after grinding is greater than or equal to 70% of -0.074 mm; in the rough flotation stage, the sodium carbonate dosage is 300 g / t to 500 g / t, the water glass dosage is 2000 g / t to 3000 g / t, the citric acid dosage is 200 g / t to 300 g / t, and the sodium oleate dosage is 1000 g / t to 1600 g / t; in the first-stage concentration, the water glass dosage is 800 g / t to 1200 g / t; and in the scavenging stage, the sodium oleate dosage is 200 g / t to 300 g / t.

[0019] Further, the product particle size after grinding in step 4 is greater than or equal to 90% of -0.038 mm, the roasting temperature is 900°C to 950°C, and the roasting time is 2 h to 3 h; the acid leaching is performed using sulfuric acid, the acid leaching temperature is 80°C to 85°C, the sulfuric acid mass concentration is 15% to 20%, and the stirring time is 1 h to 2 h.

[0020] The beneficiation method for recovering barite from tailings provided by the present application has the following key points:

[0021] 1、In the magnetic separation process, magnetic iron minerals are attracted by magnetic medium and then separated from non-magnetic minerals. Specifically, the tailings are first subjected to weak magnetic separation (1000Oe~1500Oe) to remove strong magnetic iron minerals such as magnetite from the tailings. The tailings subjected to weak magnetic separation are then subjected to strong magnetic separation (3500Gs~4500Gs) to remove weak magnetic iron minerals such as hematite, siderite, limonite, etc. In the shaking table gravity separation process, due to the influence of asymmetric reciprocating mechanical vibration of the shaking table and transverse water flow scouring, the barite gradually migrates to the concentrate area of the inclined table. Low-density gangue minerals (such as quartz) migrate to the tailings area. In this process, the barite content is significantly improved. Grinding reduces the particle size by controlling the particle size, promoting the separation of barite and associated gangue minerals, and this mechanical dissociation process optimizes the exposure of the mineral surface, thereby improving the efficiency of subsequent flotation. In the flotation process, sodium carbonate provides a weak alkaline solution environment required for barite flotation, and water glass and citric acid effectively inhibit the remaining gangue minerals such as iron minerals and quartz, and the collector sodium oleate has good collecting property for barite. After flotation separation by a roughing-two-cleaning-one-scavenging process, a rough concentrate with a BaSO4 grade of more than 94% is obtained. The rough concentrate is finely ground by stirring to further reduce the particle size, facilitating uniform heating. The barite rough concentrate after fine grinding is subjected to high-temperature roasting to promote the decomposition of impurity minerals in the tailings, while increasing the particle surface cracks, which is beneficial to improve the acid leaching effect. The rough concentrate after roasting is subjected to acid leaching to remove trace amounts of iron oxides and carbonate impurities, etc., to obtain high-quality barite concentrate with a BaSO4 grade of more than 98%.

[0022] 2、According to the difference between the iron minerals and barite in the tailings, weak and strong magnetic separation is used to remove the iron minerals. This makes the barite enriched in the magnetic separation tailings, reducing the influence of iron minerals on subsequent barite separation.

[0023] 3、The low-density gangue minerals are removed by shaking table gravity separation, which significantly improves the barite grade and reduces the difficulty of subsequent flotation operation.

[0024] 4、Water glass and citric acid are used as combined inhibitors to exert the synergistic effect between flotation reagents, reduce the dosage of reagents, enhance the inhibition effect, and make the barite and gangue impurities efficiently float and separate.

[0025] 5、Roasting and acid leaching process is used to purify barite, realizing high-value application of high-quality barite.

[0026] The method for recovering barite from tailings and purifying the same has the following beneficial effects and innovative points:

[0027] 1. A new process of magnetic separation-reselection pre-enrichment-flotation cleaning-roasting acid leaching is proposed, from low-grade tailings, barite concentrate with BaSO4 grade >98% is prepared. According to the difference of the physical and chemical properties of different minerals, the physical separation of gravity magnetic flotation and high temperature roasting, chemical leaching are combined. The process flow is reasonable in structure, high in separation efficiency, small in environmental pollution, and easy to realize industrial production.

[0028] 2. By magnetic separation and heavy separation pre-enrichment, a large amount of gangue minerals are removed, which greatly reduces the processing capacity of grinding and flotation, and the flotation reagent and flotation production cost is significantly reduced. At the same time, the pre-enrichment significantly improves the barite grade and reduces the flotation processing difficulty, making the flotation process more simple and efficient.

[0029] 3. By optimizing the shaking table gravity separation process, a roughing, cleaning and scavenging process is used to recover barite, and the improved process significantly increases the recovery rate of barite (BaSO4).

[0030] 4. Both grinding processes use agitator mills, and ceramic balls are used as grinding media. Compared with the steel balls of traditional ball mills, the iron medium on the surface of barite is avoided during grinding, which effectively improves the flotation separation efficiency. At the same time, the agitator mill grinding belongs to narrow level grinding, which makes the material finer and more uniform, which is beneficial to the separation of barite and impurity gangue minerals, and the acid leaching effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The figure is a schematic diagram of the process flow of the present application. DETAILED DESCRIPTION

[0032] The technical solutions in the present application will be described below in combination with the embodiments of the present application.

[0033] A method for recovering barite from tailings and purifying according to the present application, the process flow is as shown in Figure 1 The method comprises the following steps:

[0034] Step 1: magnetic separation for removing iron

[0035] The tailings containing barite with a particle size of ≤2mm are fed into a weak magnetic separator, and the magnetic field strength is 1000Oe~1500Oe, to obtain a weak magnetic concentrate and a weak magnetic tailings. The weak magnetic tailings are subjected to strong magnetic separation, and the background field strength is 3500Gs~4500Gs, to obtain a strong magnetic concentrate and a strong magnetic tailings. The weak magnetic concentrate and the strong magnetic concentrate are mixed to obtain an iron rough concentrate.

[0036] Step 2: shaking table gravity separation

[0037] The shaking table gravity separation process is one roughing, one scavenging and one cleaning. The shaking table stroke is 240 times / min~280 times / min, and the shaking table inclination is 2°~2.5°. The strong magnetic tailings are subjected to roughing by the shaking table to obtain a shaking table roughing concentrate, a shaking table roughing middlings and a shaking table roughing tailings. The shaking table roughing middlings are subjected to scavenging by the shaking table to obtain a shaking table scavenging concentrate and a shaking table scavenging tailings. The shaking table scavenging concentrate is subjected to cleaning by the shaking table to obtain a shaking table cleaning concentrate and a shaking table cleaning tailings. The shaking table roughing concentrate and the shaking table cleaning concentrate are combined to obtain a shaking table gravity separation concentrate, and the shaking table roughing tailings, the shaking table scavenging tailings and the shaking table cleaning tailings are combined to obtain a shaking table tailings.

[0038] Step 3: Flotation cleaning

[0039] The shaking table gravity separation concentrate is ground in a ceramic stirred mill to a content of -0.074 mm≥70%, and the ground material is subjected to flotation separation. The flotation process is one roughing, two cleanings and one scavenging. In the roughing stage, sodium carbonate 300g / t~500g / t as a pH regulator, water glass 2000g / t~3000g / t as a depressant, citric acid 200g / t~300g / t, sodium oleate 1000g / t~1600g / t as a collector are added in sequence, and the roughing is carried out by aeration and scraping to obtain a flotation roughing concentrate and a flotation roughing tailings. The flotation roughing concentrate is subjected to one-stage cleaning, and water glass 800g / t~1200g / t is added in the one-stage cleaning stage, and the one-stage cleaning is carried out by aeration and scraping to obtain a one-stage cleaning concentrate. The one-stage cleaning concentrate is subjected to two-stage cleaning, and the two-stage cleaning is carried out by aeration and scraping without adding any reagent to obtain a barite rough concentrate. The roughing tailings are subjected to scavenging, and sodium oleate 200g / t~300g / t is added in the scavenging stage, and the scavenging is carried out by aeration and scraping to obtain a flotation scavenging concentrate and a flotation tailings. The tailings of the two cleanings and the scavenging concentrate are returned to the previous operation in sequence.

[0040] Step 4: Acid leaching and roasting

[0041] The flotation barite rough concentrate is ground in a stirred mill to a content of -0.038 mm≥90%, and the ground product is subjected to high-temperature roasting for 2h~3h, and the roasting temperature is 900℃~950℃. The roasted product is subjected to sulfuric acid (mass concentration 15%~20%) acid leaching and stirring for 1h~2h, and the acid leaching temperature is 80℃~85℃. After filtration, the product is washed to neutral with distilled water and dried to obtain high-quality barite with a BaSO4 grade of >98%.

[0042] Example 1:

[0043] A method for recovering barite from tailings and purifying the barite, which adopts a process of magnetic separation and gravity separation pre-concentration, flotation cleaning, roasting and acid leaching, and uses a certain tailings as raw material, the BaSO4 grade of which is 8.02%, and the particle size is ≤2mm, and the method comprises the following steps:

[0044] (1) Magnetic separation: the tailings are fed into a low-intensity magnetic separator, the magnetic field strength is 1500 Oe, and the low-intensity magnetic concentrate and the low-intensity tailings are obtained. The low-intensity tailings are subjected to high-intensity magnetic separation, the background field strength is 3500 Gs, and the high-intensity magnetic concentrate and the high-intensity tailings are obtained. The low-intensity magnetic concentrate and the high-intensity magnetic concentrate are mixed to obtain the coarse iron concentrate.

[0045] (2) Table gravity separation: the table gravity separation process is one roughing, one scavenging and one cleaning. The table shaking frequency is 240 times / min, and the table inclination angle is 2°. The high-intensity tailings are subjected to table roughing to obtain the table roughing concentrate, the table roughing middlings and the table roughing tailings. The table roughing middlings are subjected to table scavenging to obtain the table scavenging concentrate and the tailings, and the table scavenging concentrate is subjected to table cleaning to obtain the table cleaning concentrate and the tailings. The table roughing concentrate and the table cleaning concentrate are combined to obtain the table gravity separation concentrate, and the table roughing tailings, the table scavenging tailings and the table cleaning tailings are combined to obtain the table tailings.

[0046] (3) Flotation cleaning: the table gravity separation concentrate is ground in a ceramic stirring mill to a content of -0.074 mm of 80%, and the ground material is subjected to flotation separation. The flotation process is one roughing, two cleanings and one scavenging. In the roughing stage, sodium carbonate 300 g / t, water glass 2000 g / t and citric acid 300 g / t as inhibitors, and sodium oleate 1000 g / t as a collector are added in sequence, and the roughing concentrate and the roughing tailings are obtained by aeration and scraping. The roughing concentrate is subjected to one-stage cleaning, and water glass 800 g / t is added in the one-stage cleaning stage, and the one-stage cleaning concentrate is obtained by aeration and scraping. The one-stage cleaning concentrate is subjected to two-stage cleaning, and the barite coarse concentrate is obtained by aeration and scraping without adding any reagent. The roughing tailings are subjected to scavenging, and sodium oleate 200 g / t is added in the scavenging stage, and the scavenging concentrate and the scavenging tailings are obtained by aeration and scraping. The tailings of the two cleanings and the scavenging concentrate are returned to the previous operation in sequence.

[0047] (4) Roasting and acid leaching: the flotation barite coarse concentrate is ground in a stirring mill to a content of -0.038 mm of 90%, and the ground product is subjected to high-temperature roasting for 3 h, and the roasting temperature is 900℃. The roasting product is subjected to sulfuric acid (mass concentration of 20%) acid leaching and stirring for 1 h, and the acid leaching temperature is 80℃. After filtration, the product is washed to neutral with distilled water and dried to obtain high-quality barite product.

[0048] The recovery of barite from tailings and the purification results in the embodiment are shown in Table 1.

[0049]

[0050] As can be seen from Table 1, after magnetic separation and gravity separation, about 95% of the tailings are discarded, and only 5% of the enriched tailings are subjected to grinding and flotation. Compared with direct grinding of tailings followed by magnetic separation, gravity separation and flotation, the processing capacity and energy consumption of grinding are reduced by more than 50%.

[0051] Example 2:

[0052] The embodiment provides a method for recovering barite from tailings and purifying the barite, which adopts a process of magnetic separation and gravity separation pre-concentration-flotation cleaning-roasting and acid leaching, and uses a certain tailings as raw materials, the BaSO4 grade of which is 9.35%, and the particle size is less than or equal to 2 mm, and the process includes the following steps:

[0053] (1) Magnetic separation for removing iron: the tailings are fed into a weak magnetic separator, the magnetic field strength is 1250 Oe, and weak magnetic concentrate and weak magnetic tailings are obtained. The weak magnetic tailings are subjected to strong magnetic separation, the background field strength is 4000 Gs, and strong magnetic concentrate and strong magnetic tailings are obtained. The weak magnetic concentrate and the strong magnetic concentrate are mixed to obtain the iron rough concentrate.

[0054] (2) Gravity separation by a shaking table: the process flow of the gravity separation by the shaking table is one roughing, one scavenging and one cleaning. The shaking table impact frequency is 280 times / min, and the shaking table inclination is 2.5°. The strong magnetic tailings are subjected to roughing by the shaking table to obtain the shaking table roughing concentrate, the roughing middlings and the roughing tailings. The roughing middlings are subjected to scavenging by the shaking table to obtain the shaking table scavenging concentrate and tailings, and the shaking table scavenging concentrate is subjected to cleaning by the shaking table to obtain the shaking table cleaning concentrate and tailings. The shaking table roughing concentrate and the shaking table cleaning concentrate are combined to obtain the shaking table gravity separation concentrate, and the shaking table roughing tailings, the shaking table scavenging tailings and the shaking table cleaning tailings are combined to obtain the shaking table tailings.

[0055] (3) Flotation cleaning: the shaking table gravity separation concentrate is ground in a ceramic stirring mill to a-0.074 mm content of 75%, and the ground material is subjected to flotation separation. The flotation process is one roughing, two cleanings and one scavenging. In the roughing stage, sodium carbonate 400 g / t, water glass 2500 g / t, citric acid 200 g / t, sodium oleate 1200 g / t and air are sequentially added as a pH regulator, a depressant, a collector and a scraper, and the roughing concentrate and the roughing tailings are obtained. The roughing concentrate is subjected to one-stage cleaning, and water glass 1000 g / t is added in the one-stage cleaning stage, and the one-stage cleaning concentrate is obtained by air blowing and scraping. The one-stage cleaning concentrate is subjected to two-stage cleaning, and the barite rough concentrate is obtained by air blowing and scraping without adding any reagent. The roughing tailings are subjected to scavenging, and sodium oleate 300 g / t is added in the scavenging stage, and the scavenging concentrate and the scavenging tailings are obtained by air blowing and scraping. The tailings of the two cleanings and the scavenging concentrate are sequentially returned to the previous operation.

[0056] (4) Roasting and acid leaching: the flotation barite rough concentrate is ground in a stirring mill to a-0.038 mm content of 95%, and the ground product is subjected to high-temperature roasting for 3 h, and the roasting temperature is 900℃. The roasting product is subjected to sulfuric acid (20% in mass) acid leaching and stirring for 1.5 h, and the acid leaching temperature is 80℃. After filtration, the product is washed to neutral with distilled water and dried to obtain high-quality barite products.

[0057] In the embodiment, the recovery and purification results of barite from tailings are shown in Table 2. As shown in Table 2, the tailings with a barite (BaSO4) grade of 9.35% are subjected to the process of magnetic separation and gravity separation pre-concentration-flotation cleaning-roasting and acid leaching, and high-quality barite concentrate with a BaSO4 grade of 98.66% is obtained.

[0058]

[0059] Example 3:

[0060] A method for recovering barite and purifying from tailings, using the process of magnetic separation and gravity separation pre-enrichment-flotation cleaning-roasting and acid leaching, with a certain tailings as raw material, the BaSO4 grade is 6.78%, the particle size is ≤2mm, including the following steps:

[0061] (1) Magnetic separation for removing iron: the tailings are fed into a weak magnetic separator, the magnetic field strength is 1500Oe, to obtain weak magnetic concentrate and weak magnetic tailings. The weak magnetic tailings are subjected to strong magnetic separation, the background field strength is 4500Gs, to obtain strong magnetic concentrate and strong magnetic tailings. The weak magnetic concentrate and the strong magnetic concentrate are mixed as the iron rough concentrate.

[0062] (2) Table gravity separation: the table gravity separation process flow is one roughing, one scavenging and one cleaning. The table shaking frequency is 240 times / min, and the table inclination angle is 2°. The strong magnetic tailings are subjected to table roughing to obtain table roughing concentrate, table roughing middlings and table roughing tailings. The table roughing middlings are subjected to table scavenging to obtain table scavenging concentrate and tailings, and the table scavenging concentrate is subjected to table cleaning to obtain table cleaning concentrate and tailings. The table roughing concentrate and the table cleaning concentrate are combined as the table gravity separation concentrate, and the table roughing tailings, the table scavenging tailings and the table cleaning tailings are combined as the table tailings.

[0063] (3) Flotation cleaning: the table gravity separation concentrate is ground in a ceramic stirring mill to a content of -0.074mm of 85%, and the ground material is subjected to flotation separation. The flotation process is one roughing, two cleaning and one scavenging. In the roughing stage, sodium carbonate 500g / t as pH regulator, water glass 3000g / t as depressant, citric acid 300g / t and sodium oleate 1600g / t as collector are added in sequence, and the roughing concentrate and the roughing tailings are obtained by aeration and scraping. The roughing concentrate is subjected to one-stage cleaning, and water glass 1200g / t is added in the one-stage cleaning stage, and the one-stage cleaning concentrate is obtained by aeration and scraping. The one-stage cleaning concentrate is subjected to two-stage cleaning, and the barite rough concentrate is obtained by aeration and scraping without adding any reagent. The roughing tailings are subjected to scavenging, and sodium oleate 200g / t is added in the scavenging stage, and the scavenging concentrate and the scavenging tailings are obtained by aeration and scraping. The tailings of the two cleaning stages and the scavenging concentrate are returned to the previous operation in sequence.

[0064] (4) Roasting and acid leaching: the flotation barite rough concentrate is ground in a stirring mill to a content of -0.038mm of 98%, and the ground product is subjected to high-temperature roasting for 3h, and the roasting temperature is 950℃. The roasting product is subjected to sulfuric acid (mass concentration of 20%) acid leaching and stirring for 2h, and the acid leaching temperature is 80℃. After filtration, the product is washed to neutral with distilled water and dried to obtain high-quality barite product.

[0065] The recovery and purification results of barite from tailings in this embodiment are shown in Table 3. As can be seen from Table 3, the tailings with a barite (BaSO4) grade of 6.78% can be pre-enriched by magnetic separation and gravity separation, and then subjected to flotation cleaning, roasting and acid leaching to obtain high-quality barite concentrate with a BaSO4 grade of 98.03%.

[0066]

[0067] Embodiment 4:

[0068] A method for recovering and purifying barite from tailings, which adopts a process of magnetic separation and gravity separation pre-enrichment-flotation cleaning-roasting and acid leaching, and uses tailings as raw materials, the BaSO4 grade of which is 12.85% and the particle size is ≤2mm, and includes the following steps:

[0069] (1) Magnetic separation for removing iron: the tailings are fed into a low-intensity magnetic separator with a magnetic field strength of 1000 Oe to obtain low-intensity magnetic concentrate and low-intensity magnetic tailings. The low-intensity magnetic tailings are subjected to high-intensity magnetic separation with a background field strength of 3500 Gs to obtain high-intensity magnetic concentrate and high-intensity magnetic tailings. The low-intensity magnetic concentrate and the high-intensity magnetic concentrate are mixed to obtain coarse iron concentrate.

[0070] (2) Gravity separation by shaking table: the process flow of gravity separation by shaking table is one roughing, one scavenging and one cleaning. The shaking table impact frequency is 260 times / min, and the shaking table inclination angle is 2.5°. The high-intensity magnetic tailings are subjected to roughing by shaking table to obtain shaking table roughing concentrate, roughing middlings and roughing tailings. The roughing middlings are subjected to scavenging by shaking table to obtain shaking table scavenging concentrate and tailings, and the shaking table scavenging concentrate is subjected to cleaning by shaking table to obtain shaking table cleaning concentrate and tailings. The shaking table roughing concentrate and the shaking table cleaning concentrate are combined to obtain shaking table gravity separation concentrate, and the shaking table roughing tailings, the shaking table scavenging tailings and the shaking table cleaning tailings are combined to obtain shaking table tailings.

[0071] (3) Flotation cleaning: the shaking table gravity separation concentrate is ground in a ceramic stirring mill to a content of -0.074 mm of 85%, and the ground material is subjected to flotation separation. The flotation process is one roughing, two cleanings and one scavenging. In the roughing stage, sodium carbonate 300 g / t, water glass 2000 g / t and citric acid 300 g / t as pH adjuster and depressant, and sodium oleate 1000 g / t as collector are added in sequence, and roughing concentrate and roughing tailings are obtained by aeration and scraping. The roughing concentrate is subjected to one-stage cleaning, and water glass 800 g / t is added in the one-stage cleaning stage, and one-stage cleaning concentrate is obtained by aeration and scraping. The one-stage cleaning concentrate is subjected to two-stage cleaning, and no reagent is added, and the barite coarse concentrate is obtained by aeration and scraping. The roughing tailings are subjected to scavenging, and sodium oleate 200 g / t is added in the scavenging stage, and scavenging concentrate and scavenging tailings are obtained by aeration and scraping. The tailings of the two cleanings and the scavenging concentrate are returned to the previous operation in sequence.

[0072] (4) Roasting acid leaching: the flotation barite rough concentrate is stirred and ground to a content of 95% of -0.038 mm, the ground product is roasted at a high temperature for 2 h, the roasting temperature is 950 DEG C. The roasted product is subjected to sulfuric acid (mass concentration of 15%) acid leaching and stirring for 1.5 h, the acid leaching temperature is 85 DEG C, after filtration, it is washed to neutral with distilled water and dried to obtain high-quality barite product.

[0073] The recovery of barite from tailings and the purification results in the example are shown in Table 4. As can be seen from Table 4, the tailings with a barite (BaSO4) grade of 12.85% are subjected to the process of magnetic separation and gravity pre-enrichment, flotation cleaning, roasting and acid leaching to obtain high-quality barite concentrate with a BaSO4 grade of 98.82%.

[0074]

[0075] Comparative Example 1

[0076] In the comparative example, the same strong magnetic tailings as in Example 1 are subjected to roughing under the same conditions as in Example 1, and the obtained product is the table concentrate and the table tailings.

[0077] Compared with the process of one roughing, one scavenging and one cleaning in Example 1, the separation results in the comparative example are shown in Table 5. As can be seen from Table 5, the BaSO4 recovery rate of the table concentrate is 75.81% when the process of one roughing, one cleaning and one scavenging is used to recover barite. The BaSO4 recovery rate of the table concentrate is 55.69% when one roughing is used, and the barite (BaSO4) recovery rate is increased by 20.12 percentage points and the barite grade is increased by 2.15 percentage points after the improvement of the process.

[0078]

[0079] Comparative Example 2

[0080] In the comparative example, the tailings in Example 1 are fed into a weak magnetic separator, and the weak magnetic concentrate and the weak magnetic tailings are obtained under the condition of a magnetic field strength of 1500 Oe. The tailings after magnetic separation are subjected to strong magnetic separation under the conditions of a strong magnetic background field strength of 4000 Gs, 7000 Gs and 10000 Gs, respectively, to obtain strong magnetic concentrate and strong magnetic tailings under different background field strengths. The weak magnetic concentrate and the strong magnetic concentrate are mixed to obtain different iron rough concentrates.

[0081] The results of the beneficiation data in the present comparative example are shown in Table 6. As can be seen from Table 6, with the increase of the strong magnetic background field strength, the BaSO4 grade of the strong magnetic tailings only increases from 29.30% to 32.94%, but the recovery rate decreases from 60.90% to 44.90%. This shows that too high a strong magnetic background field strength will result in a significant decrease in the recovery rate of barite. Therefore, considering the economic benefits, the strong magnetic background field strength should be controlled between 3500 Oe and 4500 Oe.

[0082]

[0083] Comparative Example 3:

[0084] The shaking table concentrate in Example 1 was subjected to flotation roughing under the condition of adding different amounts of water glass in the present comparative example, and other process conditions were the same as in Example 1, to obtain different flotation roughing concentrates. The results of the beneficiation data are shown in Table 7. As can be seen from Table 7, with the increase of the amount of water glass in the flotation roughing process, the BaSO4 grade of the flotation roughing concentrate gradually increases from 75.03% to 91.08%. This shows that a lower amount of water glass will result in a lower grade of barite, which is lower than 80%. When the amount of water glass exceeds 3000 g / t, a higher amount of water glass will result in a sharp decrease in the recovery rate of barite, from 97.44% to 86.02%. Therefore, considering comprehensively, the amount of water glass in the flotation roughing process should be controlled between 2000 g / t and 3000 g / t.

[0085]

[0086] It should be noted that the examples described in the present application are only used to further explain and illustrate, but not to limit the scope of its application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

Claims

1. A beneficiation method for recovering barite from tailings, characterized in that, Follow these steps: Step 1: Magnetic separation to remove iron: The tailings containing barite are fed into a weak magnetic separator to obtain weak magnetic concentrate and weak magnetic tailings; the weak magnetic tailings are subjected to strong magnetic separation to obtain strong magnetic concentrate and strong magnetic tailings; the weak magnetic concentrate and strong magnetic concentrate are mixed to form a coarse iron concentrate; Step 2: Shaker Reselection: The process flow of the shaking table gravity separation is one roughing, one scavenging and one concentrating: the strong magnetic tailings are subjected to shaking table roughing separation to obtain shaking table roughing concentrate, shaking table roughing ore and shaking table roughing tailings; the shaking table roughing ore is subjected to shaking table scavenging separation to obtain shaking table scavenging concentrate and shaking table scavenging tailings; the shaking table scavenging concentrate is subjected to shaking table concentrating to obtain shaking table concentrating concentrate and shaking table concentrating tailings; the shaking table roughing concentrate and shaking table concentrating concentrate are combined into shaking table gravity separation concentrate, and the shaking table roughing tailings, shaking table scavenging tailings and shaking table concentrating tailings are combined into shaking table tailings; Step 3: Flotation Selection: The shaker gravity separation concentrate is ground by a stirred mill and then subjected to flotation separation. The flotation process is one roughing, two fines, and one scavenging: in the flotation roughing stage, pH adjuster sodium carbonate, depressants water glass and citric acid, and collector sodium oleate are added in sequence, and aeration and scraping are performed to obtain flotation roughing concentrate and flotation roughing tailings; the flotation roughing concentrate undergoes first-stage concentrating, in which water glass is added and aeration and scraping are performed to obtain first-stage concentrating concentrate and first-stage concentrating tailings; the first-stage concentrating concentrate undergoes second-stage concentrating, and aeration and scraping are performed directly without adding reagents to obtain barite rough concentrate and second-stage concentrating tailings; the flotation roughing tailings undergo scavenging, in which sodium oleate is added and aeration and scraping are performed to obtain flotation scavenging concentrate and flotation tailings; the first-stage concentrating tailings, second-stage concentrating tailings, and scavenging concentrate are returned to the previous operation respectively; Step 4: Roasting and acid leaching: The barite coarse concentrate is ground by a stirred mill, and the ground product is successively subjected to high-temperature roasting, acid leaching and stirring. The obtained product is filtered and washed with distilled water to neutrality and dried to obtain high-quality barite.

2. A method for recovering barite from tailings according to claim 1, characterized in that, The particle size of the barite-containing tailings described in step 1 is ≤2mm, the magnetic field strength of the weak magnetic separator is 1000Oe~1500Oe, and the background field strength of the strong magnetic separator is 3500Gs~4500Gs.

3. A method for recovering barite from tailings according to claim 1, characterized in that, The shaking table described in step 2 has a stroke frequency of 240 to 280 times per minute and a shaking table inclination angle of 2° to 2.5°.

4. A method for recovering barite from tailings according to claim 1, characterized in that, The grinding equipment described in step 3 is a ceramic stirred mill, and the particle size of the product after grinding is -0.074mm and the content is ≥70%.

5. A method for recovering barite from tailings according to claim 1, characterized in that, In the flotation roughing stage, the dosage of sodium carbonate is 300g / t~500g / t, the dosage of water glass is 2000g / t~3000g / t, the dosage of citric acid is 200g / t~300g / t, and the dosage of sodium oleate is 1000g / t~1600g / t.

6. A method for recovering barite from tailings according to claim 1, characterized in that, The dosage of water glass in the first stage of selection is 800g / t~1200g / t; During the scavenging stage, the dosage of sodium oleate is 200g / t~300g / t.

7. A method for recovering barite from tailings according to claim 1, characterized in that, The particle size of the ground product in step 4 is -0.038mm and the content is ≥90%, the roasting temperature is 900℃~950℃, and the roasting time is 2h~3h.

8. A method for recovering barite from tailings according to claim 1, characterized in that, Acid leaching is carried out using sulfuric acid, the acid leaching temperature is 80°C~85°C, the mass concentration of sulfuric acid is 15%~20%, and the stirring time is 1h~2h.

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