Process for recovering tungsten from molybdenum tailings

Abstract

The application provides a method for recovering tungsten from molybdenum tailings, comprising the following steps: centrifugal gravity separation of the molybdenum tailings to obtain centrifugal concentrate and centrifugal tailings; feeding the centrifugal concentrate into a spiral chute for secondary separation to obtain spiral chute concentrate and spiral chute tailings; conventional flotation of the spiral chute concentrate to obtain primary roughing concentrate, primary scavenging concentrate and scavenging tailings; mixing the primary roughing concentrate and the primary scavenging concentrate and feeding the mixture into a cyclone classifier, the overflow of the cyclone classifier being subjected to gravity separation operation on a table, and the underflow of the cyclone classifier being subjected to grinding in a ball mill, the ball mill and the cyclone classifier forming a closed circuit grinding system to obtain table concentrate and table tailings; three times of cleaning and one time of cleaning scavenging of the table tailings to obtain flotation concentrate and cleaning scavenging tailings; mixing the table concentrate and the flotation concentrate to obtain tungsten concentrate; and mixing the centrifugal tailings, the spiral chute tailings, the scavenging tailings and the cleaning scavenging tailings to obtain total tailings. The application improves the recovery rate of the tungsten concentrate.

Description

Technical Field

[0001] This application relates to the field of mineral processing technology, and in particular to a method for recovering tungsten from molybdenum tailings. Background Technology

[0002] Tungsten and molybdenum are two non-renewable strategic mineral resources, widely used in steel, military, aerospace, electronics, electrical appliances, and chemical industries due to their unique properties. With the long-term exploitation of tungsten resources, easily beneficiated high-grade ore is increasingly scarce, and a large amount of tungsten exists as a by-product in associated mineral deposits such as molybdenum ore, entering the tailings during molybdenum beneficiation. my country generates a large amount of molybdenum tailings annually, containing valuable metals such as tungsten and molybdenum of a certain grade, representing a valuable secondary mineral resource. Comprehensive recovery of associated tungsten resources from molybdenum tailings not only helps alleviate the increasingly tight supply and demand contradiction of tungsten resources in my country but is also an important way to realize the resource utilization of mine solid waste and reduce environmental pollution from tailings storage.

[0003] Currently, the existing technologies for recovering tungsten from molybdenum tailings mainly involve combined processes, such as gravity separation pre-enrichment-flotation combined processes. However, due to the low grade and fine particle size of tungsten resources in molybdenum tailings, there is a general problem of low tungsten recovery rate, resulting in the loss of fine-grained tungsten minerals with the tailings. Summary of the Invention

[0004] This application provides a method for recovering tungsten from molybdenum tailings to solve the problems mentioned in the background art.

[0005] This application provides a method for recovering tungsten from molybdenum tailings, comprising the following steps: (1) The molybdenum tailings are fed to a centrifuge for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings. Under strong centrifugal force, rapid separation is achieved, and the centrifuge can achieve a large enrichment of tungsten minerals in a short time. (2) The centrifugal concentrate is fed into the spiral sluice for further separation to obtain spiral sluice concentrate and spiral sluice tailings. By combining centrifugal force, gravity and sluice surface friction, the minerals are stratified according to density, and the tungsten grade of the centrifugal concentrate is further improved. (3) The spiral sluice concentrate is subjected to conventional flotation, including one pre-cleaning roughing and one scavenging, to obtain one roughing concentrate, one scavenging concentrate and scavenging tailings; (4) After mixing the primary roughing concentrate and the primary scavenging concentrate, the mixture is fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters the shaking table for gravity separation, and the underflow from the hydrocyclone enters the ball mill for grinding. The ball mill and the hydrocyclone form a closed-circuit grinding process to obtain the shaking table concentrate and the shaking table tailings. (5) The tailings from the shaking table are fed into the flotation machine for three cleaning processes and one scavenging process to obtain flotation concentrate and scavenging tailings; The shaking table concentrate and the flotation concentrate are mixed to obtain tungsten concentrate, and the centrifugal tailings, spiral sluice tailings, scavenging tailings and fine scavenging tailings are mixed to obtain total tailings.

[0006] Optionally, during the centrifugal gravity separation process, the feed concentration of the centrifuge is 30-35%, and the proportion of particles with a size of -200 mesh or less is more than 70%.

[0007] Optionally, the centrifuge speed is 1800-2200 r / min, and the rising water flow is 2.5-3 L / min.

[0008] Optionally, the feed concentration of the spiral chute is 20%-25%.

[0009] Optionally, the feed concentration for the first pre-cleaning roughing stage is 30%-35%; Pre-selection and roughing reagent system: Sodium oleate dosage 200-300g / t; water glass dosage 1500-2000g / t.

[0010] Optionally, during the hydrocyclone classification process, the proportion of hydrocyclone overflow fineness below -0.074mm is 80%-90%.

[0011] Optionally, the stroke of the shaking table is 12-14 mm, and the number of strokes is 280-320 times / min; The fineness of the concentrate obtained by shaking table is less than -325 mesh, reaching 70-80%.

[0012] Optional, the three-stage selection and one-stage fine scan specifically include: The tailings from the shaking table are fed into a slurry to obtain shaking table tailings slurry, which is then fed into a flotation machine for three cleaning operations and one fine scavenging operation. The first cleaning operation yields concentrate 1 and tailings 1. Tailings 1 is then subjected to a fine scavenging operation to obtain fine scavenged concentrate and fine scavenged tailings. Concentrate 1 and fine scavenged concentrate are then subjected to a second cleaning operation to obtain concentrate 2 and tailings 2. Concentrate 2 is then subjected to a third cleaning operation to obtain flotation concentrate and tailings 3. Tailings 2 is returned to the second cleaning operation, and tailings 3 is returned to the third cleaning operation.

[0013] Optional reagent system for fine selection operation 1: sodium carbonate dosage 500-800g / t, water glass dosage 1000-1400g / t; reagent system for fine selection operation 2: water glass dosage 200-500g / t; reagent system for fine selection operation 3: water glass dosage 50-100g / t; reagent system for single fine scavenging: octylhydroxyvalerate dosage 50-100g / t.

[0014] Optionally, the feed concentration of the tailings slurry for the shaking table is 30-35%, the slurry temperature is 80℃, and the stirring time is 90 minutes.

[0015] The method for recovering tungsten from molybdenum tailings provided in this application achieves highly efficient tungsten recovery and has the following advantages compared to existing technologies: (1) This application first uses centrifugal gravity separation as the first stage of pre-enrichment process. Utilizing the specific gravity difference between tungsten minerals and gangue minerals, rapid separation is achieved under strong centrifugal force, resulting in significant enrichment of tungsten minerals and centrifugal concentrate and tailings. The centrifugal concentrate is fed into a spiral sluice for further separation, further improving the tungsten grade of the centrifugal concentrate, resulting in spiral sluice concentrate and spiral sluice tailings. The spiral sluice concentrate is subjected to conventional flotation with one pre-cleaning roughing and one scavenging to avoid resource loss of tungsten minerals. The roughing concentrate and the scavenging concentrate are mixed and fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters a shaking table for operation, achieving precise separation of tungsten minerals and gangue. The underflow from the hydrocyclone enters a ball mill for grinding, resulting in shaking table concentrate and shaking table tailings. The tailings from the shaking table flotation process undergo three cleaning stages and one scavenging stage to obtain flotation concentrate and scavenging tailings. The shaking table concentrate and flotation concentrate are mixed to obtain tungsten concentrate. The centrifugal tailings, spiral sluice box tailings, scavenging tailings, and scavenging tailings are mixed to obtain total tailings. By combining centrifugal gravity separation, spiral sluice box separation, conventional flotation, classification, grinding, shaking table gravity separation, and three cleaning stages, high-grade, fine-grained tungsten concentrate is recovered, while the overall recovery rate of tungsten concentrate is improved, and the waste of tungsten resources is reduced.

[0016] (2) By controlling the feed concentration of the spiral sluice to 20%-25%, it is beneficial for the slurry to form a stable flow film on the surface of the spiral sluice, so that minerals with different specific gravities can be effectively separated under the combined action of centrifugal force and gravity. The spiral sluice has the advantages of large throughput, no power required, and low operating cost. It plays an important role in further enriching tungsten minerals and improving the feed grade of subsequent flotation operations.

[0017] (3) During the pre-selection and roughing process, the pH value of the pulp is adjusted to 9-10 by adding sodium carbonate. Under alkaline conditions, the solubility and selectivity of sodium oleate can be enhanced, thereby improving the collection of tungsten minerals and improving the grade of tungsten concentrate. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A process flow diagram of a method for recovering tungsten from molybdenum tailings provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0021] like Figure 1 As shown, this application provides a method for recovering tungsten from molybdenum tailings, comprising the following steps: (1) The molybdenum tailings are fed to a centrifuge for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings; (2) The centrifugal concentrate is fed into a spiral sluice for further separation to obtain spiral sluice concentrate and spiral sluice tailings; (3) The spiral sluice concentrate is subjected to conventional flotation, including one pre-cleaning roughing and one scavenging, to obtain one roughing concentrate, one scavenging concentrate and scavenging tailings; (4) After mixing the primary roughing concentrate and the primary scavenging concentrate, the mixture is fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters the shaking table for gravity separation, and the underflow from the hydrocyclone enters the ball mill for grinding. The ball mill and the hydrocyclone form a closed-circuit grinding process to obtain the shaking table concentrate and the shaking table tailings. (5) The tailings from the shaking table are fed into the flotation machine for three cleaning processes and one scavenging process to obtain flotation concentrate and scavenging tailings; The shaking table concentrate and the flotation concentrate are mixed to obtain tungsten concentrate, and the centrifugal tailings, spiral sluice tailings, scavenging tailings and fine scavenging tailings are mixed to obtain total tailings.

[0022] Specifically, in the tungsten recovery process of this application, centrifugal gravity separation is first used as the first pre-enrichment step, utilizing tungsten minerals (density approximately 6.1-7.5 g / cm³). 3 ) and gangue minerals (density approximately 2.6-2.8 g / cm³) 3 The difference in specific gravity between the tungsten and gangue minerals allows for rapid separation under strong centrifugal force. Centrifuges can significantly enrich tungsten minerals in a short time, while pre-removing a large amount of low-density gangue minerals, thus significantly reducing the processing volume in subsequent operations. Using centrifugal gravity separation as the first pre-enrichment process can remove 50%-60% of the tailings in advance, reducing reagent consumption and equipment load in subsequent flotation stages.

[0023] Among them, the WO3 grade of molybdenum tailings is 0.008%-0.014%, and the WO3 grade of centrifuged concentrate is ≥0.1%.

[0024] The centrifuged concentrate is fed into a spiral sluice for further separation, yielding spiral sluice concentrate and spiral sluice tailings. The spiral sluice utilizes the film motion of the slurry on the spiral sluice surface, combined with centrifugal force, gravity, and surface friction, to achieve mineral stratification by density, further increasing the tungsten grade of the centrifuged concentrate. Simultaneously, the spiral sluice tailings are removed, achieving further refining. Furthermore, the spiral sluice has low energy consumption and low operating costs, making it a crucial step in achieving further refining of tungsten minerals and reducing beneficiation costs. The spiral sluice concentrate has a WO3 grade ≥ 0.5%.

[0025] The concentrate from the spiral sluice is subjected to conventional flotation consisting of a pre-cleaning rougher and a scavenging flotation. The pre-cleaning rougher removes some of the easily floatable gangue, reducing the burden on subsequent cleaning operations. The tailings from the pre-cleaning rougher are then subjected to a scavenging flotation to recover tungsten minerals, thus preventing the loss of tungsten resources. The grade of the concentrate from the first rougher and the concentrate from the first scavenging flotation is WO3 ≥ 10%.

[0026] The roughing concentrate and scavenging concentrate from the first stage are mixed and fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters a shaking table for gravity separation. The differential motion of the shaking table and the thin-layer water flow achieve precise separation of tungsten minerals and gangue. The underflow from the hydrocyclone enters a ball mill for grinding. The ball mill and hydrocyclone form a closed-circuit grinding system, yielding shaking table concentrate and shaking table tailings. This grinding process allows for the return of insufficiently liberated intergrowths for regrinding, ensuring that the material entering the shaking table has a good degree of individual liberation, which is beneficial for the collection of tungsten ore in subsequent beneficiation processes.

[0027] The tailings from the shaking table flotation machine undergo three cleaning processes and one scavenging process to obtain flotation concentrate and scavenging tailings, thereby improving the overall recovery rate of tungsten concentrate. The shaking table concentrate and flotation concentrate are mixed to obtain tungsten concentrate, while the centrifugal tailings, spiral sluice tailings, scavenging tailings, and scavenging tailings are mixed to obtain total tailings.

[0028] This application achieves efficient recovery of tungsten concentrate through the above-described scheme. First, centrifugal gravity separation is used as the first pre-enrichment process. Utilizing the specific gravity difference between tungsten minerals and gangue minerals, rapid separation is achieved under strong centrifugal force, resulting in significant enrichment of tungsten minerals in a short time, yielding centrifugal concentrate and tailings. The centrifugal concentrate is then fed into a spiral sluice for further separation, further increasing the tungsten grade, yielding spiral sluice concentrate and spiral sluice tailings. The spiral sluice concentrate undergoes conventional flotation with one pre-cleaning roughing and one scavenging. The pre-cleaning roughing removes some easily floatable gangue, reducing the burden on subsequent cleaning operations. The tailings from the pre-cleaning roughing are then scavenged to recover tungsten minerals, preventing resource loss. The primary roughing and scavenging concentrates are mixed and fed into a hydrocyclone for classification. The hydrocyclone overflow enters a shaking table for precise separation of tungsten minerals and gangue. The hydrocyclone underflow enters a ball mill for grinding, yielding shaking table concentrate and shaking table tailings. The tailings from the shaking table flotation process undergo three cleaning stages and one scavenging stage to obtain flotation concentrate and scavenging tailings. The shaking table concentrate and flotation concentrate are mixed to obtain tungsten concentrate. The centrifugal tailings, spiral sluice box tailings, scavenging tailings, and scavenging tailings are mixed to obtain total tailings. By combining centrifugal gravity separation, spiral sluice box separation, conventional flotation, classification, grinding, shaking table gravity separation, and three cleaning stages, high-grade, fine-grained tungsten concentrate is recovered, while the overall recovery rate of tungsten concentrate is improved, and the waste of tungsten resources is reduced.

[0029] Optionally, during the centrifugal gravity separation process, the feed concentration of the centrifuge is 30-35%, and the proportion of particles with a size of -200 mesh or less is more than 70%.

[0030] Specifically, by controlling the feed concentration of the centrifuge at 30%-35%, the slurry has appropriate fluidity and stratification during the centrifugation process, which is conducive to the separation between tungsten minerals and gangue minerals; at the same time, the particle size is controlled to be below -200 mesh, accounting for more than 70%, to ensure that the tungsten minerals are fully liberated.

[0031] Optionally, the centrifuge speed is 1800-2200 r / min, and the rising water flow is 2.5-3 L / min.

[0032] Specifically, a high centrifugal force field can effectively recover fine-grained heavy minerals. The centrifuge can recover fine-grained minerals down to the micrometer level, and it has a better recovery effect on tungsten minerals.

[0033] Optionally, the feed concentration of the spiral chute is 20%-25%.

[0034] Specifically, controlling the feed concentration of the spiral sluice to 20%-25% is beneficial for the formation of a stable film on the surface of the spiral sluice, enabling the effective separation of minerals with different specific gravities under the combined action of centrifugal force and gravity. The spiral sluice has advantages such as large throughput, no power required, and low operating costs. It plays a crucial role in further enriching tungsten minerals and improving the feed grade for subsequent flotation operations.

[0035] Optionally, the feed concentration for the first pre-cleaning roughing stage is 30%-35%; Pre-selection and roughing reagent system: Sodium oleate dosage 200-300g / t; water glass dosage 1500-2000g / t.

[0036] Specifically, sodium oleate, as an effective collector for tungsten minerals, exhibits excellent collecting performance for scheelite. Water glass, as a depressant, effectively inhibits gangue minerals such as quartz and silicates, ensuring selectivity in the roughing operation. The flotation process, consisting of one pre-cleaning roughing and one scavenging stage, can obtain a high-grade roughing concentrate while ensuring recovery. Further enrichment through flotation provides a higher-grade feed for subsequent cleaning operations.

[0037] Furthermore, during the pre-selection and roughing process, sodium carbonate is added to adjust the pH of the pulp to 9-10. In an alkaline environment, the solubility and selectivity of sodium oleate can be enhanced, thereby improving the collection of tungsten minerals and increasing the grade of tungsten concentrate.

[0038] Optionally, during the hydrocyclone classification process, the overflow fineness of the hydrocyclone is 80%-90% below -0.074mm, which ensures that the particle size of the material entering the shaking table is suitable for the shaking table gravity separation.

[0039] Optionally, the stroke of the shaking table is 12-14 mm, and the number of strokes is 280-320 times / min; The fineness of the shaker concentrate is less than -325 mesh, reaching 70-80%, which can obtain high-grade, fine-grained tungsten concentrate products, which can be directly used as part of the final tungsten concentrate.

[0040] Furthermore, a 6-S shaking table is selected. Optionally, the three-stage fine selection and one-stage fine sweeping process specifically includes: The tailings from the shaking table are fed into a slurry to obtain shaking table tailings slurry, which is then fed into a flotation machine for three cleaning operations and one fine scavenging operation. The first cleaning operation yields concentrate 1 and tailings 1. Tailings 1 is then subjected to a fine scavenging operation to obtain fine scavenged concentrate and fine scavenged tailings. Concentrate 1 and fine scavenged concentrate are then subjected to a second cleaning operation to obtain concentrate 2 and tailings 2. Concentrate 2 is then subjected to a third cleaning operation to obtain flotation concentrate and tailings 3. Tailings 2 is returned to the second cleaning operation, and tailings 3 is returned to the third cleaning operation.

[0041] Specifically, the scavenging process recovers residual tungsten minerals from tailings 1, and the scavenging concentrate is then fed into the second beneficiation process to prevent resource loss and improve the overall tungsten ore recovery rate. Tailings 2 is returned to the second beneficiation process, and tailings 3 is returned to the third beneficiation process, forming an internal circulation of middlings. This reduces the interference of middlings circulation on the main process and further stabilizes the tungsten concentrate grade.

[0042] Optional reagent system for fine selection operation 1: sodium carbonate dosage 500-800g / t, water glass dosage 1000-1400g / t; reagent system for fine selection operation 2: water glass dosage 200-500g / t; reagent system for fine selection operation 3: water glass dosage 50-100g / t; reagent system for single fine scavenging: octylhydroxyvalerate dosage 50-100g / t.

[0043] Specifically, the first purification process uses a high amount of sodium carbonate and water glass, which can strongly suppress gangue; the second and third purification processes gradually reduce the amount of water glass to reduce the suppression of tungsten minerals and achieve gradual purification.

[0044] Optionally, the feed concentration of the tailings slurry for the shaking table is 30-35%, the slurry temperature is 80℃, and the stirring time is 90 minutes.

[0045] Specifically, a slurry conditioning temperature of 80°C combined with 90 minutes of long-term stirring is beneficial for the full adsorption and action of reagents on the mineral surface, thereby improving flotation selectivity.

[0046] The following are embodiments and effect test examples of this application, further describing the technical solution and technical effects of the present invention. However, the scope of protection of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not depart from the concept of the present invention are within the scope of protection of the present invention. Furthermore, unless specific technical operation steps or conditions are specified in the embodiments, they are performed according to the techniques or conditions described in general literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially. All percentages of ore concentration in this application are mass percentages.

[0047] Example 1

[0048] A method for recovering tungsten from molybdenum tailings includes the following steps: (1) The molybdenum tailings (WO3 grade: 0.009%) were fed to a centrifuge at a feed concentration of 35% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings; the molybdenum tailings had a particle size of less than -200 mesh, accounting for 78%. The centrifuge speed was 1800-1900 r / min and the rising water flow was 2.5 / min.

[0049] (2) The centrifugal concentrate is fed into the spiral sluice at a feed concentration of 20% to separate again, to obtain spiral sluice concentrate and spiral sluice tailings.

[0050] (3) The spiral sluice concentrate is fed to the conventional flotation process at a feed concentration of 20% to carry out one pre-selection roughing and one scavenging to obtain one roughing concentrate, one scavenging concentrate and scavenging tailings; the pre-selection roughing reagent system is as follows: sodium oleate dosage 200g / t; water glass dosage 2000g / t.

[0051] (4) After mixing the primary roughing concentrate and the primary scavenging concentrate, the mixture is fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters a shaking table for gravity separation, and the underflow from the hydrocyclone enters a ball mill for grinding. The ball mill and the hydrocyclone form a closed-circuit grinding process to obtain shaking table concentrate and shaking table tailings. The overflow fineness of the hydrocyclone is 90% below -0.074mm. A 6-S shaking table is selected, with a stroke of 12mm and a stroke rate of 280 times / min.

[0052] (5) The tailings from the shaking table are fed into the slurry to obtain the tailings slurry, which is then fed into the flotation machine for three cleaning operations and one scavenging operation. The first cleaning operation yields concentrate 1 and tailings 1. Tailings 1 is then subjected to a first scavenging operation to obtain scavenged concentrate and scavenged tailings. Concentrate 1 and scavenged concentrate are then subjected to a second cleaning operation to obtain concentrate 2 and tailings 2. Concentrate 2 is then subjected to a third cleaning operation to obtain flotation concentrate and tailings 3. Tailings 2 is returned to the second cleaning operation, and tailings 3 is returned to the third cleaning operation. Flotation concentrate and scavenged tailings are obtained. The shaking table concentrate and flotation concentrate are mixed to obtain tungsten concentrate. The centrifugal tailings, spiral sluice tailings, scavenged tailings and scavenged tailings are mixed to obtain total tailings.

[0053] Selective treatment system 1: Sodium carbonate dosage 500g / t, water glass dosage 1100g / t; Selective treatment system 2: Water glass dosage 200g / t; Selective treatment system 3: Water glass dosage 50g / t; Primary fine scavenging reagent system: Octylhydroxyvalerate dosage 60g / t; The feed concentration of tailings slurry for shaking table is 30%, the slurry temperature is 80℃, and the stirring time is 90min.

[0054] Example 2

[0055] A method for recovering tungsten from molybdenum tailings includes the following steps: (1) The molybdenum tailings (WO3 grade: 0.012%) were fed to a centrifuge at a feed concentration of 30% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings; the molybdenum tailings had a particle size of less than -200 mesh, accounting for 82%. The centrifuge speed was 1900-2000 r / min and the rising water flow was 3 L / min.

[0056] (2) The centrifugal concentrate is fed into the spiral sluice at a feed concentration of 20% for further separation to obtain spiral sluice concentrate and spiral sluice tailings.

[0057] (3) The spiral sluice concentrate is fed to the conventional flotation process at a feed concentration of 25% for one pre-selection roughing and one scavenging to obtain one roughing concentrate, one scavenging concentrate and scavenging tailings; the reagent system for pre-selection roughing is: sodium oleate dosage 250g / t; water glass dosage 1600g / t.

[0058] (4) After mixing the primary roughing concentrate and the primary scavenging concentrate, the mixture is fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters a shaking table for gravity separation, and the underflow from the hydrocyclone enters a ball mill for grinding. The ball mill and the hydrocyclone form a closed-circuit grinding process to obtain shaking table concentrate and shaking table tailings. The overflow fineness of the hydrocyclone is 90% below -0.074mm. A 6-S shaking table is selected, with a stroke of 14mm and a stroke rate of 320 times / min.

[0059] (5) The tailings from the shaking table are fed into the slurry to obtain the tailings slurry, which is then fed into the flotation machine for three cleaning operations and one scavenging operation. The first cleaning operation yields concentrate 1 and tailings 1. Tailings 1 is then subjected to a first scavenging operation to obtain scavenged concentrate and scavenged tailings. Concentrate 1 and scavenged concentrate are then subjected to a second cleaning operation to obtain concentrate 2 and tailings 2. Concentrate 2 is then subjected to a third cleaning operation to obtain flotation concentrate and tailings 3. Tailings 2 is returned to the second cleaning operation, and tailings 3 is returned to the third cleaning operation. Flotation concentrate and scavenged tailings are obtained. The shaking table concentrate and flotation concentrate are mixed to obtain tungsten concentrate. The centrifugal tailings, spiral sluice tailings, scavenged tailings and scavenged tailings are mixed to obtain total tailings.

[0060] Selective treatment system 1: Sodium carbonate dosage 670g / t, water glass dosage 1000g / t; Selective treatment system 2: Water glass dosage 300g / t; Selective treatment system 3: Water glass dosage 80g / t; Primary fine scavenging reagent system: Octylhydroxyvalerate dosage 100g / t; The feed concentration of tailings slurry for shaking table is 35%, the slurry conditioning temperature is 80℃, and the stirring time is 90min.

[0061] Example 3

[0062] A method for recovering tungsten from molybdenum tailings includes the following steps: (1) The molybdenum tailings (WO3 grade: 0.011%) were fed to a centrifuge at a feed concentration of 30% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings; the molybdenum tailings had a particle size of less than -200 mesh, accounting for 88%. The centrifuge speed was 2000-2200 r / min, and the rising water flow was 3 L / min.

[0063] (2) The centrifugal concentrate is fed into the spiral sluice at a feed concentration of 25% for further separation to obtain spiral sluice concentrate and spiral sluice tailings.

[0064] (3) The spiral sluice concentrate is fed to the conventional flotation process at a feed concentration of 22% for one pre-selection roughing and one scavenging to obtain one roughing concentrate, one scavenging concentrate and scavenging tailings; the reagent system for pre-selection roughing is: sodium oleate dosage 300g / t; water glass dosage 2000g / t.

[0065] (4) After mixing the primary roughing concentrate and the primary scavenging concentrate, the mixture is fed into a hydrocyclone for classification. The overflow from the hydrocyclone enters a shaking table for gravity separation, and the underflow from the hydrocyclone enters a ball mill for grinding. The ball mill and the hydrocyclone form a closed-circuit grinding process to obtain shaking table concentrate and shaking table tailings. The overflow fineness of the hydrocyclone is 80% below -0.074mm. A 6-S shaking table is selected, with a stroke of 12mm and a stroke rate of 300 times / min.

[0066] (5) The tailings from the shaking table are fed into the slurry to obtain the tailings slurry, which is then fed into the flotation machine for three cleaning operations and one scavenging operation. The first cleaning operation yields concentrate 1 and tailings 1. Tailings 1 is then subjected to a first scavenging operation to obtain scavenged concentrate and scavenged tailings. Concentrate 1 and scavenged concentrate are then subjected to a second cleaning operation to obtain concentrate 2 and tailings 2. Concentrate 2 is then subjected to a third cleaning operation to obtain flotation concentrate and tailings 3. Tailings 2 is returned to the second cleaning operation, and tailings 3 is returned to the third cleaning operation. Flotation concentrate and scavenged tailings are obtained. The shaking table concentrate and flotation concentrate are mixed to obtain tungsten concentrate. The centrifugal tailings, spiral sluice tailings, scavenged tailings and scavenged tailings are mixed to obtain total tailings.

[0067] Selective treatment system 1: Sodium carbonate dosage 800g / t, water glass dosage 1000g / t; Selective treatment system 2: Water glass dosage 200g / t; Selective treatment system 3: Water glass dosage 50g / t; Primary fine scavenging reagent system: Octylhydroxyvalerate dosage 100g / t; The feed concentration of tailings slurry for shaking table is 35%, the slurry conditioning temperature is 80℃, and the stirring time is 90min.

[0068] Comparative Example 1 A method for recovering tungsten from molybdenum tailings includes the following steps: The difference from Example 2 is that: (1) Without centrifugal gravity separation, the molybdenum tailings (WO3 grade: 0.008%) are fed into the spiral sluice at a feed concentration of 20% to obtain spiral sluice concentrate and spiral sluice tailings.

[0069] The yield, tungsten grade, and tungsten recovery rate of molybdenum tailings, tungsten concentrate, and final total tailings in Examples 1-3 and Comparative Example 1 are summarized in Table 1, and the results are shown in the table below.

[0070] Table 1

[0071] As shown in Table 1, the recovery rate of tungsten concentrate in Examples 1-3 was significantly improved compared with Comparative Example 1. This indicates that by using centrifugal gravity separation as the first pre-enrichment process, tungsten minerals and gangue minerals can be rapidly separated under strong centrifugal force, and a large amount of low-density gangue minerals can be pre-discarded. This allows for a large amount of waste to be discarded at the beginning of the beneficiation process, which helps to accurately select tungsten concentrate in the subsequent beneficiation process, thereby improving the grade of tungsten concentrate.

[0072] Example 4 A method for recovering tungsten from molybdenum tailings includes the following steps: The difference from Example 2 is that: (1) The molybdenum tailings (WO3 grade: 0.012%) were fed to a centrifuge at a feed concentration of 30% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings.

[0073] (4) During the pre-selection and roughing process, sodium carbonate is added to adjust the pH of the pulp to 10.

[0074] Example 5 A method for recovering tungsten from molybdenum tailings includes the following steps: The difference from Example 2 is that: (1) The molybdenum tailings (WO3 grade: 0.010%) were fed to a centrifuge at a feed concentration of 30% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings.

[0075] (4) During the pre-selection and roughing process, the pH value of the pulp is adjusted to 9 by adding sodium carbonate.

[0076] Comparative Example 2 A method for recovering tungsten from molybdenum tailings includes the following steps: The difference from Example 2 is that: (1) The molybdenum tailings (WO3 grade: 0.009%) were fed to a centrifuge at a feed concentration of 30% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings.

[0077] (5) Selective cleaning process 1: Sodium carbonate dosage 670g / t (without water glass); Selective cleaning process 2: Water glass dosage 300g / t; Selective cleaning process 3: Water glass dosage 80g / t; Primary fine cleaning process: Octyl hydroxyvalerate dosage 100g / t; The feed concentration of tailings slurry for shaking table is 35%, the slurry temperature is 80℃, and the stirring time is 90min.

[0078] Comparative Example 3 A method for recovering tungsten from molybdenum tailings includes the following steps: The difference from Example 2 is that: (1) The molybdenum tailings (WO3 grade: 0.008%) were fed to a centrifuge at a feed concentration of 30% for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings.

[0079] (5) Selective cleaning process 1: Sodium carbonate dosage 670g / t, water glass dosage 1000g / t; Selective cleaning process 2: Water glass dosage 300g / t; Selective cleaning process 3: Water glass dosage 110g / t; Primary fine cleaning process: Octyl hydroxyvalerate dosage 100g / t; The feed concentration of tailings slurry for shaking table is 35%, the slurry temperature is 80℃, and the stirring time is 90min.

[0080] The yield, tungsten grade, and tungsten recovery rate of molybdenum tailings, tungsten concentrate, and final total tailings in Examples 4, 5, Comparative Example 2, and Comparative Example 3 are summarized in Table 2, and the results are shown in the table below.

[0081] Table 2

[0082] Table 2 clearly shows that during the pre-cleaning and roughing process, adding sodium carbonate to adjust the pulp pH to alkaline enhances the solubility and selectivity of sodium oleate, thereby improving the collection of tungsten minerals and increasing the grade of tungsten concentrate. Meanwhile, in Comparative Example 2, the amount of sodium carbonate used in the first cleaning operation was 670 g / t, and no water glass was used. In Comparative Example 3, the amount of water glass used in the third cleaning operation was excessive. This indicates that in the three cleaning and one fine scavenging operations of this application, by accurately controlling and coordinating the reagents used in the first, second, and third cleaning operations and the first fine scavenging process, gangue can be strongly suppressed, thereby improving the grade of tungsten concentrate.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for recovering tungsten from molybdenum tailings, characterized in that, Includes the following steps: (1) The molybdenum tailings are fed to a centrifuge for centrifugal gravity separation to obtain centrifuged concentrate and centrifuged tailings; (2) The centrifugal concentrate is fed into a spiral sluice for further separation to obtain spiral sluice concentrate and spiral sluice tailings; (3) The spiral sluice concentrate is subjected to conventional flotation, including one pre-cleaning roughing and one scavenging, to obtain a roughing concentrate, a scavenging concentrate and scavenging tailings; (4) The primary roughing concentrate and the primary scavenging concentrate are mixed and fed into a hydrocyclone for classification. The overflow of the hydrocyclone enters a shaking table for gravity separation, and the underflow of the hydrocyclone enters a ball mill for grinding. The ball mill and the hydrocyclone form a closed-circuit grinding process to obtain shaking table concentrate and shaking table tailings. (5) The tailings from the shaking table enter the flotation machine for three cleaning and one scavenging processes to obtain flotation concentrate and scavenging tailings; The shaking table concentrate and the flotation concentrate are mixed to obtain tungsten concentrate, and the centrifugal tailings, the spiral sluice tailings, the scavenging tailings and the fine scavenging tailings are mixed to obtain total tailings.

2. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, During the centrifugal gravity separation process, the feed concentration of the centrifuge is 30-35%, and the proportion of particles with a size of -200 mesh or less is more than 70%.

3. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, The centrifuge has a rotation speed of 1800-2200 r / min and an upward water flow rate of 2.5-3 L / min.

4. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, The feed concentration of the spiral chute is 20%-25%.

5. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, The feed concentration for the primary pre-cleaning roughing process is 30%-35%; The pre-selection and roughing reagent system is as follows: sodium oleate dosage 200-300 g / t; water glass dosage 1500-2000 g / t.

6. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, During the hydrocyclone grading process, the proportion of hydrocyclone overflow fineness below -0.074mm is 80%-90%.

7. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, The stroke of the shaking table is 12-14 mm, and the number of strokes is 280-320 times / min; The fineness of the concentrate obtained by the shaking table is less than -325 mesh, reaching 70-80%.

8. The method for recovering tungsten from molybdenum tailings according to claim 1, characterized in that, The three-stage selection and one-stage fine-scan selection specifically include: The tailings from the shaking table are fed into a slurry to obtain shaking table tailings slurry, which is then fed into a flotation machine for three cleaning operations and one scavenging operation. The first cleaning operation yields concentrate 1 and tailings 1. Tailings 1 is then subjected to a scavenging operation to obtain scavenged concentrate and scavenged tailings. Concentrate 1 and scavenged concentrate are then subjected to a second cleaning operation to obtain concentrate 2 and tailings 2. Concentrate 2 is then subjected to a third cleaning operation to obtain flotation concentrate and tailings 3. Tailings 2 are returned to the second cleaning operation, and tailings 3 are returned to the third cleaning operation.

9. The method for recovering tungsten from molybdenum tailings according to claim 8, characterized in that, The first-stage fine scavenging process uses the following reagents: sodium carbonate dosage 500-800 g / t, water glass dosage 1000-1400 g / t; the second-stage fine scavenging process uses the following reagents: water glass dosage 200-500 g / t; the third-stage fine scavenging process uses the following reagents: water glass dosage 50-100 g / t; and the first-stage fine scavenging process uses the following reagents: octylhydroxyvalerate dosage 50-100 g / t.

10. The method for recovering tungsten from molybdenum tailings according to any one of claims 1-9, characterized in that, The feed concentration of the tailings slurry for the shaking table is 30-35%, the slurry temperature is 80℃, and the stirring time is 90 minutes.

Images