Process for enriching tungsten and molybdenum by three-stage gravity separation from ammonium paratungstate and metallurgical slag

Abstract

This invention discloses a three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag, belonging to the field of tungsten and molybdenum processing technology. It includes: S1: raw material pretreatment; S2: primary roughing; S3: secondary cleaning; S4: tertiary scavenging. This invention is green and environmentally friendly, with no secondary pollution: the entire process uses physical gravity separation, without adding chemical reagents, resulting in no waste gas or wastewater pollution. The leaching of harmful elements from tailings meets standards, achieving harmless treatment and solving the pollution problems of pyrometallurgical and hydrometallurgical processes. It boasts high recovery rates and good enrichment effects: the three-stage targeted separation—roughing for tailings removal, cleaning for enrichment, and scavenging for recovery—results in high tungsten and molybdenum recovery rates, solving the problems of low recovery rates and insufficient grade in single gravity separation.

Description

Technical Field

[0001] This invention belongs to the field of tungsten and molybdenum process technology, specifically involving a three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag. Background Technology

[0002] Tungsten is an important strategic rare metal, and molybdenum is a key alloying element; both have wide applications in industry. Ammonium paratungstate (APT) is a core intermediate product in tungsten metallurgy. Industrial production employs an alkali-boiling-ion-evaporation crystallization process, which generates a large amount of APT metallurgical slag (alkali-boiled tungsten slag). Each ton of APT production emits 0.7-1.3 tons of metallurgical slag, with domestic stockpiles reaching nearly one million tons, and an annual increase of 70,000-80,000 tons. This wastes land and easily causes environmental pollution.

[0003] This metallurgical slag contains gangue such as fluorapatite, calcite, and spodumene, with residual WO3 of 1.0%-5.5% and Mo of 0.4%-1.8%. It also contains heavy metals such as copper, zinc, arsenic, and mercury, and is classified as hazardous waste. Its harmless and resource-based treatment urgently needs to be addressed.

[0004] Existing recycling processes are mainly divided into three categories: pyrometallurgical, hydrometallurgical, and gravity separation. Pyrometallurgical processes have high energy consumption and large equipment investment, and high-temperature roasting easily produces harmful gases, resulting in secondary pollution. Hydrometallurgical processes consume large amounts of reagents, are difficult to treat wastewater, and suffer from severe equipment corrosion. They also have poor recovery efficiency and significant loss of fine tungsten and molybdenum particles. Gravity separation alone has insufficient separation accuracy, poor adaptability to coarse and fine particles, and lacks scavenging recovery. Tungsten and molybdenum recovery rates are low, with tungsten only reaching 75%-85% and molybdenum only reaching 70%-80%. It is difficult to meet the concentrate grade, and the agglomeration of fine mud further reduces the separation efficiency, resulting in low resource utilization.

[0005] In response to the problems of high energy consumption, heavy pollution, low recovery rate, poor enrichment effect, unreasonable process and weak adaptability of existing technologies, there is an urgent need to develop a green and environmentally friendly, low energy consumption, high recovery rate, stable concentrate grade and suitable for large-scale industrial application of ammonium paratungstate metallurgical slag tungsten and molybdenum enrichment process. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned technical problems and provide a three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag, which solves the problems of high energy consumption, heavy pollution, low recovery rate, poor enrichment effect, unreasonable process and weak adaptability of the existing technology.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag includes the following steps: S1: Raw material pretreatment: crush and grind the ammonium paratungstate metallurgical slag, and control the grinding fineness to 65%-90% of the particles with a particle size of -0.074mm; after grinding, adjust the slurry to a mass concentration of 25%-40%, add 0.01%-0.05% of the metallurgical slag mass of dispersant, and stir evenly. S2: First stage roughing: The pretreated slurry is fed into the spiral chute for roughing, with the rotation speed controlled at 18-28 r / min, the slurry flow rate at 0.8-1.5 m / s, and the separation temperature at 15-35℃, to obtain roughing concentrate and roughing tailings. The roughing tailings are directly discarded. S3: Second stage of cleaning: The rougher concentrate is slurry adjusted to a mass concentration of 20%-30% and sent to a shaking table for cleaning. The stroke is controlled at 12-20mm, the stroke rate at 280-380 times / min, and the transverse slope at 1.5°-3.5° to obtain tungsten-molybdenum mixed concentrate and middlings. S4: Three-stage scavenging: The middlings are slurry adjusted to a mass concentration of 28%-38% and fed into a centrifugal concentrator for scavenging. The rotation speed is controlled at 3000-5000 r, the centrifugal force at 20-50 g, and the backwash water flow rate at 4.5-7.5 L / min to obtain scavenged concentrate and scavenged tailings. The scavenged tailings are discarded, and the scavenged concentrate is returned to the second-stage scavenging cycle. The ammonium paratungstate metallurgical slag is ammonium paratungstate alkaline boiling slag with an original particle size ≤50mm, a moisture content of 8%-18%, and contains WO3 1.0%-5.5% and Mo 0.4%-1.8%. Tungsten is found in scheelite, molybdenum in molybdenite, and gangue is fluorapatite, calcite, and sparstone.

[0008] Furthermore, the S1 dispersant is one or both of sodium polyacrylate and sodium hexametaphosphate, and the stirring speed is 150-300 r / min and the stirring time is 10-25 min.

[0009] Furthermore, the S1 grinding process uses a ball mill with steel ball diameter of 10-30 mm, a ball-to-material ratio of 3-5:1, and a grinding time of 30-90 min.

[0010] Furthermore, the S2 spiral chute has a diameter of 600-1200mm, 3-5 turns, and a feeding speed of 1.2-2.0m / s. 3 / h; roughing concentrate yield 12%-22%, tailings WO3≤0.5%, Mo≤0.2%.

[0011] Furthermore, the S3 shaking table is double-layered, with a table surface length of 1.8-2.8m and a width of 0.8-1.5m; the concentrate has WO3 ≥ 35.0%, Mo ≥ 4.5%, and a medium mineral yield of 8%-18%.

[0012] Furthermore, the S4 centrifugal concentrator is a Nelson type with a processing capacity of 0.5-1.5m³. 3 / h; scavenged concentrate WO3≥8.0%, Mo≥1.2%, tailings WO3≤0.3%, Mo≤0.15%.

[0013] Furthermore, in steps S2 to S4, clean water is used for slurry preparation, and the stirring speed is 180-320 r / min for 8-18 min.

[0014] Furthermore, the sorting temperature is 20-30℃; when the ambient temperature is <15℃, the ore is heated to ≤35℃.

[0015] Furthermore, the scavenging concentrate and the roughing concentrate are mixed at a ratio of 1:3 to 1:5, and the mixed concentrate with a concentration of 22% to 28% is returned to the cleaner.

[0016] The beneficial effects of this invention are as follows: (1) Green and environmentally friendly, with no secondary pollution: The entire process adopts physical gravity separation, without adding chemical agents, and there is no waste gas or wastewater pollution. The leaching of harmful elements in the tailings meets the standards, achieving harmless treatment and solving the pollution problems of pyrometallurgical and hydrometallurgical processes.

[0017] (2) High recovery rate and good enrichment effect: Three-stage targeted separation, roughing and tailing, fine enrichment and scavenging recovery, tungsten recovery rate and molybdenum recovery rate are both high, solving the problem of low recovery rate and insufficient grade of single gravity separation.

[0018] (3) Simple process and strong adaptability: The process is short, the equipment is mature and the operation is simple. It can be adapted to metallurgical slags of different grades and different embedded particle sizes, solving the problems of poor adaptability and complicated process of existing processes.

[0019] (4) Low energy consumption and controllable cost: No high-temperature roasting and strong acid and strong alkali leaching are required, which significantly reduces energy consumption. No reagents are required, and the scavenging concentrate can be recycled, resulting in low processing costs and solving the problems of high energy consumption and high cost of existing processes.

[0020] (5) High resource utilization rate: It realizes efficient recovery of tungsten and molybdenum, and the tailings can be utilized as resources, reducing stockpiling and waste, and solving the problems of resource loss and low utilization rate. Attached Figure Description

[0021] Figure 1 This is a diagram of the three-stage gravity separation enrichment process for tungsten and molybdenum in ammonium paratungstate metallurgical slag according to the present invention.

[0022] In the attached image: 1 is ammonium paratungstate metallurgical slag; 2 is crushing; 3 is grinding; 4 is slurry conditioning + dispersant; 5 is primary roughing (spiral chute); 6 is roughing tailings (tailings discarded); 7 is roughing concentrate; 8 is secondary cleaning (shaking table); 9 is cleaning concentrate (tungsten-molybdenum mixed concentrate); 10 is cleaning middlings; 11 is tertiary scavenging (centrifugal concentrator); 12 is scavenging tailings (tailings discarded); 13 is scavenging concentrate; 14 is returned to secondary cleaning. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] refer to Figure 1 As shown in the figure, this embodiment provides a three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag. The ammonium paratungstate metallurgical slag used in this invention is all alkali boiling slag produced by alkali decomposition during the production process of ammonium paratungstate, with an original particle size ≤50mm and a moisture content of 8%-18%. The main gangue minerals are fluorapatite, calcite, and sparstone. Tungsten mainly exists in the form of scheelite, and molybdenum mainly exists in the form of molybdenite. The dispersants used are industrial-grade sodium polyacrylate and sodium hexametaphosphate. The equipment used are all mature industrial equipment, including a grate ball mill, fiberglass spiral chute, double-layer shaking table, and Nelson centrifugal concentrator. The tungsten and molybdenum grades and recovery rates are detected by atomic absorption spectrophotometry.

[0025] Example 1 The ammonium paratungstate metallurgical slag used in this embodiment contains 1.0% tungsten trioxide (WO3), 0.4% molybdenum (Mo), 8% moisture, and an original particle size of no more than 50 mm.

[0026] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 10 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 3:1 and the grinding time is set to 30 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 65% to ensure that tungsten and molybdenum minerals are fully dissociated from gangue minerals, creating conditions for subsequent separation. The material after grinding is slurried with clean water. The slurry mass concentration is controlled at 25%. Sodium polyacrylate is added to the slurry as a dispersant. The amount of dispersant added is 0.01% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 150 r / min and the stirring time is 10 min to fully disperse the solid particles in the slurry, eliminate the agglomeration of fine mud, and ensure that the slurry is uniform and stable.

[0027] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 600 mm, and the number of spiral turns is 3. During the separation process, the main shaft speed of the spiral chute is controlled at 18 r / min, the slurry flow rate is 0.8 m / s, and the slurry feed rate is 1.2 m / s. 3 The separation environment temperature is controlled at 15℃ per hour. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 12%, and the rougher tailings contain 0.5% WO3 and 0.2% Mo. The valuable metal content of the rougher tailings is extremely low, so they are directly discarded and will not be used in subsequent separation processes.

[0028] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration is controlled at 20% after slurry treatment. During the slurry treatment, the stirring speed is set to 180 r / min and the stirring time is 8 min to ensure that the slurry is evenly dispersed and free from agglomeration, meeting the requirements of shaking table separation. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 1.8 m and a bed width of 0.8 m. During the separation process, the shaking table stroke is controlled at 12 mm, the stroke rate is 280 times / min, and the transverse slope is 1.5°. After separation by the double-layer shaking table, the cleaned concentrate (i.e., tungsten-molybdenum mixed concentrate) and cleaned middlings are obtained. The WO3 grade in the cleaned concentrate is 35.0%, and the Mo grade is 4.5%, meeting the requirements for subsequent deep processing raw materials. The yield of the cleaned middlings is 8%, containing a certain amount of unrecovered tungsten and molybdenum minerals, which need to be further separated and recovered.

[0029] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 28%. During the slurry preparation, the stirring speed is set to 180 r / min and the stirring time is 8 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 0.5 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 3000 r / min, the centrifugal force is 20g (g is the acceleration due to gravity), and the backwash water flow rate is 4.5 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 8.0% WO3 and 1.2% Mo, and the scavenging tailings contain 0.3% WO3 and 0.15% Mo. The scavenging tailings have extremely low valuable metal content and are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:3. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 22% and returned to the second stage cleaning process. It is then fed into a double-layer shaking table together with the roughing concentrate for circulating enrichment to improve the recovery rate of tungsten and molybdenum metals.

[0030] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 89.5%, and the molybdenum metal recovery rate was 82.3%.

[0031] Example 2 The ammonium paratungstate metallurgical slag used in this embodiment contains 1.5% tungsten trioxide (WO3), 0.6% molybdenum (Mo), and 10% moisture, with an original particle size not exceeding 50 mm.

[0032] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 15 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 3.5:1 and the grinding time is set at 40 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 70% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 28%. Sodium hexametaphosphate is added to the slurry as a dispersant. The amount of dispersant added is 0.02% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 180 r / min and the stirring time is 12 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0033] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 700 mm, and the number of spiral turns is 3. During the separation process, the spindle speed of the spiral chute is controlled at 20 r / min, the slurry flow rate is 1.0 m / s, and the slurry feed rate is 1.4 m / s. 3 The separation environment temperature is controlled at 18℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 14%, and the rougher tailings contain 0.48% WO3 and 0.19% Mo, which are directly discarded.

[0034] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 22%. During the slurry treatment, the stirring speed is set to 200 r / min and the stirring time is 10 min to ensure that the slurry is evenly dispersed and free of agglomeration. The slurry after slurry treatment is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.0 m and a bed width of 1.0 m. During the separation process, the shaking table stroke is controlled at 14 mm, the stroke rate is 300 times / min, and the transverse slope is 1.8°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 36.2%, the Mo grade is 4.7%, and the yield of clean middlings is 10%.

[0035] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 30%. During the slurry preparation, the stirring speed is set to 200 r / min and the stirring time is 10 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 0.7 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 3500 r / min, the centrifugal force at 25g, and the backwash water flow rate at 5.0 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 8.5% WO3 and 1.3% Mo, and the scavenging tailings contain 0.28% WO3 and 0.14% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:3.5. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 23% and returned to the second stage cleaning process for recycling and enrichment.

[0036] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 90.8%, and the molybdenum metal recovery rate was 83.7%.

[0037] Example 3 The ammonium paratungstate metallurgical slag used in this embodiment contains 2.0% tungsten trioxide (WO3), 0.8% molybdenum (Mo), and 12% moisture content, with an original particle size not exceeding 50 mm.

[0038] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 20 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4:1 and the grinding time is set at 50 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 75% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 30%. A mixed dispersant of sodium polyacrylate and sodium hexametaphosphate with a mass ratio of 1:1 is added to the slurry. The amount of dispersant added is 0.03% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 200 r / min and the stirring time is 15 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0039] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 800 mm, and the number of spiral turns is 4. During the separation process, the main shaft speed of the spiral chute is controlled at 22 r / min, the slurry flow rate is 1.1 m / s, and the slurry feed rate is 1.5 m / s. 3 The separation environment temperature is controlled at 20℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 16%, and the rougher tailings contain 0.45% WO3 and 0.18% Mo, which are directly discarded.

[0040] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 24%. During the slurry treatment, the stirring speed is set to 220 r / min and the stirring time is 12 min to ensure that the slurry is evenly dispersed and free of agglomeration. The slurry after slurry treatment is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.2 m and a bed width of 1.1 m. During the separation process, the shaking table stroke is controlled at 15 mm, the stroke rate is 320 times / min, and the transverse slope is 2.0°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 37.5%, the Mo grade is 4.9%, and the yield of clean middlings is 12%.

[0041] (4) Three-stage scavenging: The middlings obtained from the above two-stage scavenging are treated with clean water to form a slurry. The slurry concentration after scavenging is controlled at 32%. During the slurry scavenging process, the stirring speed is set to 220 r / min and the stirring time is 12 min to ensure that the slurry is evenly dispersed and has good fluidity. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The selected Nelson centrifugal concentrator has a capacity of 0.9 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4000 r / min, the centrifugal force at 30g, and the backwash water flow rate at 5.5 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.0% WO3 and 1.4% Mo, and the scavenging tailings contain 0.25% WO3 and 0.13% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 24% and returned to the second stage cleaning process for recycling and enrichment.

[0042] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 91.6%, and the molybdenum metal recovery rate was 84.9%.

[0043] Example 4 The ammonium paratungstate metallurgical slag used in this embodiment contains 2.5% tungsten trioxide (WO3), 1.0% molybdenum (Mo), and 13% moisture, with an original particle size not exceeding 50 mm.

[0044] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 20 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4:1 and the grinding time is set to 60 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 75% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 30%. Sodium polyacrylate is added to the slurry as a dispersant. The amount of dispersant added is 0.03% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 220 r / min and the stirring time is 16 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0045] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 800 mm, and the number of spiral turns is 4. During the separation process, the spindle speed of the spiral chute is controlled at 22 r / min, the slurry flow rate is 1.2 m / s, and the slurry feed rate is 1.6 m / s. 3 The separation environment temperature is controlled at 22℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 16%, and the rougher tailings contain 0.42% WO3 and 0.17% Mo, which are directly discarded.

[0046] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 25%. During the slurry treatment, the stirring speed is set to 240 r / min and the stirring time is 13 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.2 m and a bed width of 1.2 m. During the separation process, the shaking table stroke is controlled at 16 mm, the stroke rate is 330 times / min, and the transverse slope is 2.2°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 38.3%, the Mo grade is 5.1%, and the yield of clean middlings is 13%.

[0047] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 33%. During the slurry preparation, the stirring speed is set to 240 r / min and the stirring time is 13 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.0 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4000 r / min, the centrifugal force at 32 g, and the backwash water flow rate at 5.8 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.2% WO3 and 1.5% Mo, and the scavenging tailings contain 0.24% WO3 and 0.12% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 25% and returned to the second stage cleaning process for recycling and enrichment.

[0048] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 92.3%, and the molybdenum metal recovery rate was 85.8%.

[0049] Example 5 The ammonium paratungstate metallurgical slag used in this embodiment contains 3.0% tungsten trioxide (WO3), 1.2% molybdenum (Mo), and 14% moisture, with an original particle size not exceeding 50 mm.

[0050] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 25 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4.5:1 and the grinding time is set at 70 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 80% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 32%. Sodium hexametaphosphate is added to the slurry as a dispersant. The amount of dispersant added is 0.04% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 250 r / min and the stirring time is 18 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0051] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 900 mm, and the number of spiral turns is 4. During the separation process, the main shaft speed of the spiral chute is controlled at 24 r / min, the slurry flow rate is 1.2 m / s, and the slurry feed rate is 1.7 m / s. 3 The separation environment temperature is controlled at 24℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 18%, and the rougher tailings contain 0.40% WO3 and 0.16% Mo, which are directly discarded.

[0052] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 26%. During the slurry treatment, the stirring speed is set to 260 r / min and the stirring time is 14 min to ensure that the slurry is evenly dispersed and free of agglomeration. The slurry after slurry treatment is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.4 m and a bed width of 1.2 m. During the separation process, the shaking table stroke is controlled at 17 mm, the stroke rate is 340 times / min, and the transverse slope is 2.5°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 39.1%, the Mo grade is 5.3%, and the yield of clean middlings is 14%.

[0053] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 34%. During the slurry preparation, the stirring speed is set to 260 r / min and the stirring time is 14 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.1 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4200 r / min, the centrifugal force at 35 g, and the backwash water flow rate at 6.0 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.5% WO3 and 1.6% Mo, and the scavenging tailings contain 0.22% WO3 and 0.11% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.2. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 26% and returned to the second stage cleaning process for recycling and enrichment.

[0054] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 93.1%, and the molybdenum metal recovery rate was 86.7%.

[0055] Example 6 The ammonium paratungstate metallurgical slag used in this embodiment contains 3.5% tungsten trioxide (WO3), 1.3% molybdenum (Mo), and 15% moisture content, with an original particle size not exceeding 50 mm.

[0056] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 25 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4.5:1 and the grinding time is set at 75 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 80% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 33%. A mixed dispersant with a mass ratio of sodium polyacrylate and sodium hexametaphosphate of 2:1 is added to the slurry. The amount of dispersant added is 0.04% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 260 r / min and the stirring time is 19 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0057] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 900 mm, and the number of spiral turns is 4. During the separation process, the spindle speed of the spiral chute is controlled at 24 r / min, the slurry flow rate is 1.3 m / s, and the slurry feed rate is 1.7 m / s. 3 The separation environment temperature is controlled at 25℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 18%, and the rougher tailings contain 0.38% WO3 and 0.15% Mo, which are directly discarded.

[0058] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 26%. During the slurry treatment, the stirring speed is set to 270 r / min and the stirring time is 15 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.4 m and a bed width of 1.3 m. During the separation process, the shaking table stroke is controlled at 17 mm, the stroke rate is 350 times / min, and the transverse slope is 2.6°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 39.8%, the Mo grade is 5.4%, and the yield of clean middlings is 15%.

[0059] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 35%. During the slurry preparation process, the stirring speed is set to 270 r / min and the stirring time is 15 min to ensure uniform dispersion and good fluidity of the slurry. The slurry that has passed the scavenging process is then fed into a Nelson centrifugal concentrator for scavenging. The selected Nelson centrifugal concentrator has a capacity of 1.2 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4300 r / min, the centrifugal force at 38 g, and the backwash water flow rate at 6.2 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.8% WO3 and 1.7% Mo, and the scavenging tailings contain 0.21% WO3 and 0.10% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.3. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 26% and returned to the second stage cleaning process for recycling and enrichment.

[0060] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 93.7%, and the molybdenum metal recovery rate was 87.3%.

[0061] Example 7 The ammonium paratungstate metallurgical slag used in this embodiment contains 4.0% tungsten trioxide (WO3), 1.4% molybdenum (Mo), and 16% moisture, with an original particle size not exceeding 50 mm.

[0062] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. 30mm diameter steel balls are used as grinding media during the grinding process, with a ball-to-material mass ratio of 5:1 and a grinding time of 80 minutes. After grinding, the proportion of -0.074mm particles in the grinding product is controlled to be 85% to ensure sufficient dissociation of tungsten and molybdenum minerals from gangue minerals. The qualified grinding material is slurried with clean water, and the slurry concentration is controlled to be 35%. Sodium polyacrylate is added to the slurry as a dispersant, with an addition amount of 0.04% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started, with a stirring speed of 280 r / min and a stirring time of 20 minutes to fully disperse the slurry, eliminate fine mud agglomeration, and ensure uniform and stable slurry.

[0063] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 1000 mm and 5 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 26 r / min, the slurry flow rate is 1.3 m / s, and the slurry feed rate is 1.8 m / s. 3 The separation environment temperature is controlled at 27℃ per hour. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 20%, and the rougher tailings contain 0.36% WO3 and 0.14% Mo, which are directly discarded.

[0064] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 28%. During the slurry treatment, the stirring speed is set to 280 r / min and the stirring time is 16 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.6 m and a bed width of 1.3 m. During the separation process, the shaking table stroke is controlled at 18 mm, the stroke rate is 360 times / min, and the transverse slope is 2.8°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 40.5%, the Mo grade is 5.6%, and the yield of clean middlings is 16%.

[0065] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 36%. During the slurry preparation, the stirring speed is set to 280 r / min and the stirring time is 16 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.3 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4500 r / min, the centrifugal force at 40 g, and the backwash water flow rate at 6.5 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 10.0% WO3 and 1.8% Mo, and the scavenging tailings contain 0.20% WO3 and 0.09% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.5. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 27% and returned to the second stage cleaning process for recycling and enrichment.

[0066] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 94.5%, and the molybdenum metal recovery rate was 88.1%.

[0067] Example 8 The ammonium paratungstate metallurgical slag used in this embodiment contains 4.5% tungsten trioxide (WO3), 1.6% molybdenum (Mo), and 17% moisture, with an original particle size not exceeding 50 mm.

[0068] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. 30mm diameter steel balls are used as grinding media during the grinding process, with a ball-to-material mass ratio of 5:1 and a grinding time of 85 minutes. After grinding, the proportion of -0.074mm particles in the grinding product is controlled to be 85% to ensure sufficient dissociation of tungsten and molybdenum minerals from gangue minerals. The qualified grinding material is slurried with clean water, and the slurry concentration is controlled to be 37%. Sodium hexametaphosphate is added to the slurry as a dispersant, with an addition amount of 0.05% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started, with a stirring speed of 290 r / min and a stirring time of 22 minutes to fully disperse the slurry, eliminate fine mud agglomeration, and ensure uniform and stable slurry.

[0069] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 1100 mm and 5 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 26 r / min, the slurry flow rate is 1.4 m / s, and the slurry feed rate is 1.9 m / s. 3 The separation environment temperature is controlled at 29℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 20%, and the rougher tailings contain 0.34% WO3 and 0.13% Mo, which are directly discarded.

[0070] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 28%. During the slurry treatment, the stirring speed is set to 290 r / min and the stirring time is 17 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.6 m and a bed width of 1.4 m. During the separation process, the shaking table stroke is controlled at 19 mm, the stroke rate is 370 times / min, and the transverse slope is 3.0°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 41.2%, the Mo grade is 5.8%, and the yield of clean middlings is 17%.

[0071] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 37%. During the slurry preparation, the stirring speed is set to 290 r / min and the stirring time is 17 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.4 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4800 r / min, the centrifugal force at 45 g, and the backwash water flow rate at 7.0 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 10.5% WO3 and 1.9% Mo, and the scavenging tailings contain 0.18% WO3 and 0.08% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.8. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 27% and returned to the second stage cleaning process for recycling and enrichment.

[0072] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 95.3%, and the molybdenum metal recovery rate was 89.2%.

[0073] Example 9 The ammonium paratungstate metallurgical slag used in this embodiment contains 5.5% tungsten trioxide (WO3), 1.8% molybdenum (Mo), and 18% moisture, with an original particle size not exceeding 50 mm.

[0074] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 30 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 5:1 and the grinding time is set to 90 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 90% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 40%. A mixed dispersant with a mass ratio of sodium polyacrylate and sodium hexametaphosphate of 3:1 is added to the slurry. The amount of dispersant added is 0.05% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set to 300 r / min and the stirring time is 25 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0075] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 1200 mm and 5 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 28 r / min, the slurry flow rate is 1.5 m / s, and the slurry feed rate is 2.0 m / s. 3 The separation environment temperature is controlled at 35℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 22%, and the rougher tailings contain 0.32% WO3 and 0.12% Mo, which are directly discarded.

[0076] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 30%. During the slurry treatment, the stirring speed is set to 320 r / min and the stirring time is 18 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.8 m and a bed width of 1.5 m. During the separation process, the shaking table stroke is controlled at 20 mm, the stroke rate is 380 times / min, and the transverse slope is 3.5°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 42.0%, the Mo grade is 6.0%, and the yield of clean middlings is 18%.

[0077] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 38%. During the slurry preparation, the stirring speed is set to 320 r / min and the stirring time is 18 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The selected Nelson centrifugal concentrator has a capacity of 1.5 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 5000 r / min, the centrifugal force at 50 g, and the backwash water flow rate at 7.5 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 11.0% WO3 and 2.0% Mo, while the scavenging tailings contain 0.15% WO3 and 0.07% Mo, and are directly discarded as tailings. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:5. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 28% and returned to the second stage cleaning process for recycling and enrichment.

[0078] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 96.2%, and the molybdenum metal recovery rate was 90.1%.

[0079] Example 10 The ammonium paratungstate metallurgical slag used in this embodiment contains 2.0% tungsten trioxide (WO3), 0.8% molybdenum (Mo), 12% moisture, and an initial particle size of no more than 50 mm. The initial temperature of the sorting environment is 12℃.

[0080] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 20 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4:1 and the grinding time is set at 50 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 75% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurry prepared with clean water. The slurry mass concentration is controlled at 30%. Sodium polyacrylate is added to the prepared slurry as a dispersant. The amount of dispersant added is 0.03% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 200 r / min and the stirring time is 15 min to fully disperse the slurry and eliminate fine mud agglomeration. Since the ambient temperature is below 15℃, the prepared slurry is heated and kept warm to control the slurry temperature at 20℃ to ensure good slurry fluidity.

[0081] (2) First-stage roughing: The pretreated, uniform, and temperature-controlled slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 800 mm and 4 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 22 r / min, the slurry flow rate is 1.1 m / s, and the slurry feed rate is 1.5 m / s. 3 The separation environment temperature is controlled at 20℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 16%, and the rougher tailings contain 0.44% WO3 and 0.17% Mo, which are directly discarded.

[0082] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 24%. During the slurry treatment, the stirring speed is set to 220 r / min and the stirring time is 12 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.2 m and a bed width of 1.1 m. During the separation process, the shaking table stroke is controlled at 15 mm, the stroke rate is 320 times / min, and the transverse slope is 2.0°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 37.3%, the Mo grade is 4.8%, and the yield of clean middlings is 12%.

[0083] (4) Three-stage scavenging: The middlings obtained from the above two-stage scavenging are treated with clean water to form a slurry. The slurry concentration after scavenging is controlled at 32%. During the slurry scavenging process, the stirring speed is set to 220 r / min and the stirring time is 12 min to ensure that the slurry is evenly dispersed and has good fluidity. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The selected Nelson centrifugal concentrator has a capacity of 0.9 m³ / min.3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4000 r / min, the centrifugal force at 30g, and the backwash water flow rate at 5.5 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 8.9% WO3 and 1.4% Mo, while the scavenging tailings contain 0.24% WO3 and 0.12% Mo, and are directly discarded as tailings. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 24% and returned to the second stage cleaning process for recycling and enrichment.

[0084] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 91.4%, and the molybdenum metal recovery rate was 84.7%.

[0085] Example 11 In this embodiment, the ammonium paratungstate metallurgical slag contains 3.0% tungsten trioxide (WO3), 1.2% molybdenum (Mo), and 14% moisture. The original particle size is no greater than 50 mm. The dispersant is a mixture of sodium polyacrylate and sodium hexametaphosphate in a mass ratio of 1:2.

[0086] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 25 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4.5:1 and the grinding time is set at 70 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 80% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 32%. A mixed dispersant with a mass ratio of sodium polyacrylate and sodium hexametaphosphate of 1:2 is added to the slurry. The amount of dispersant added is 0.04% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 250 r / min and the stirring time is 18 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0087] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 900 mm, and the number of spiral turns is 4. During the separation process, the main shaft speed of the spiral chute is controlled at 24 r / min, the slurry flow rate is 1.2 m / s, and the slurry feed rate is 1.7 m / s. 3 The separation environment temperature is controlled at 24℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 18%, and the rougher tailings contain 0.40% WO3 and 0.16% Mo, which are directly discarded.

[0088] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 26%. During the slurry treatment, the stirring speed is set to 260 r / min and the stirring time is 14 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.4 m and a bed width of 1.2 m. During the separation process, the shaking table stroke is controlled at 17 mm, the stroke rate is 340 times / min, and the transverse slope is 2.5°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 39.0%, the Mo grade is 5.2%, and the yield of clean middlings is 14%.

[0089] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 34%. During the slurry preparation, the stirring speed is set to 260 r / min and the stirring time is 14 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.1 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4200 r / min, the centrifugal force at 35 g, and the backwash water flow rate at 6.0 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.4% WO3 and 1.5% Mo, and the scavenging tailings contain 0.22% WO3 and 0.11% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.2. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 26% and returned to the second stage cleaning process for recycling and enrichment.

[0090] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 93.0%, and the molybdenum metal recovery rate was 86.5%.

[0091] Example 12 The ammonium paratungstate metallurgical slag used in this embodiment contains 2.2% tungsten trioxide (WO3), 0.9% molybdenum (Mo), 12% moisture, and an initial particle size of no more than 50 mm. The initial temperature of the sorting environment is 10℃.

[0092] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 20 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4:1 and the grinding time is set at 55 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 76% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurry prepared with clean water. The slurry mass concentration is controlled at 31%. Sodium hexametaphosphate is added to the prepared slurry as a dispersant. The amount of dispersant added is 0.03% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 210 r / min and the stirring time is 16 min to fully disperse the slurry and eliminate fine mud agglomeration. Since the ambient temperature is below 15℃, the prepared slurry is heated and kept warm to control the slurry temperature at 22℃ to ensure good slurry fluidity.

[0093] (2) First-stage roughing: The pretreated, uniform, and temperature-controlled slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 800 mm and 4 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 22 r / min, the slurry flow rate is 1.1 m / s, and the slurry feed rate is 1.5 m / s. 3 The separation environment temperature is controlled at 22℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 16%, and the rougher tailings contain 0.43% WO3 and 0.17% Mo, which are directly discarded.

[0094] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 24%. During the slurry treatment, the stirring speed is set to 220 r / min and the stirring time is 12 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.2 m and a bed width of 1.1 m. During the separation process, the shaking table stroke is controlled at 15 mm, the stroke rate is 320 times / min, and the transverse slope is 2.1°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 37.8%, the Mo grade is 4.9%, and the yield of clean middlings is 12%.

[0095] (4) Three-stage scavenging: The middlings obtained from the above two-stage scavenging are treated with clean water to form a slurry. The slurry concentration after scavenging is controlled at 32%. During the slurry scavenging process, the stirring speed is set to 220 r / min and the stirring time is 12 min to ensure that the slurry is evenly dispersed and has good fluidity. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The selected Nelson centrifugal concentrator has a capacity of 0.9 m³ / min.3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4000 r / min, the centrifugal force at 30g, and the backwash water flow rate at 5.6 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 8.8% WO3 and 1.4% Mo, and the scavenging tailings contain 0.23% WO3 and 0.12% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 24% and returned to the second stage cleaning process for recycling and enrichment.

[0096] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 91.8%, and the molybdenum metal recovery rate was 85.1%.

[0097] Example 13 The ammonium paratungstate metallurgical slag used in this embodiment contains 3.8% tungsten trioxide (WO3), 1.4% molybdenum (Mo), and 16% moisture. The original particle size is no greater than 50 mm. The dispersant is a mixture of sodium polyacrylate and sodium hexametaphosphate in a mass ratio of 4:1.

[0098] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 30 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 5:1 and the grinding time is set to 80 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 85% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 36%. A mixed dispersant with a mass ratio of sodium polyacrylate and sodium hexametaphosphate of 4:1 is added to the slurry. The amount of dispersant added is 0.04% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set to 280 r / min and the stirring time is 20 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0099] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 1000 mm and 5 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 26 r / min, the slurry flow rate is 1.3 m / s, and the slurry feed rate is 1.8 m / s. 3 The separation environment temperature is controlled at 28℃ per hour. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 20%, and the rougher tailings contain 0.35% WO3 and 0.14% Mo, which are directly discarded.

[0100] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 28%. During the slurry treatment, the stirring speed is set to 280 r / min and the stirring time is 16 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.6 m and a bed width of 1.3 m. During the separation process, the shaking table stroke is controlled at 18 mm, the stroke rate is 360 times / min, and the transverse slope is 2.9°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 40.2%, the Mo grade is 5.5%, and the yield of clean middlings is 16%.

[0101] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 36%. During the slurry preparation, the stirring speed is set to 280 r / min and the stirring time is 16 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.3 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4500 r / min, the centrifugal force at 40 g, and the backwash water flow rate at 6.4 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.9% WO3 and 1.7% Mo, and the scavenging tailings contain 0.20% WO3 and 0.09% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.5. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 27% and returned to the second stage cleaning process for recycling and enrichment.

[0102] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 94.3%, and the molybdenum metal recovery rate was 87.9%.

[0103] Example 14 The ammonium paratungstate metallurgical slag used in this embodiment contains 1.8% tungsten trioxide (WO3), 0.7% molybdenum (Mo), and 11% moisture content. The original particle size is no more than 50 mm, and the ball milling ball-to-material mass ratio is 3.8:1.

[0104] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 18 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 3.8:1 and the grinding time is set at 45 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 72% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 29%. Sodium polyacrylate is added to the slurry as a dispersant. The amount of dispersant added is 0.02% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 190 r / min and the stirring time is 13 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0105] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 750 mm, and the number of spiral turns is 3. During the separation process, the main shaft speed of the spiral chute is controlled at 21 r / min, the slurry flow rate is 1.0 m / s, and the slurry feed rate is 1.4 m / s. 3 The separation environment temperature is controlled at 19℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 15%, and the rougher tailings contain 0.46% WO3 and 0.18% Mo, which are directly discarded.

[0106] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 23%. During the slurry treatment, the stirring speed is set to 210 r / min and the stirring time is 11 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.1 m and a bed width of 1.0 m. During the separation process, the shaking table stroke is controlled at 14 mm, the stroke rate is 310 times / min, and the transverse slope is 1.9°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 36.5%, the Mo grade is 4.6%, and the yield of clean middlings is 11%.

[0107] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 31%. During the slurry preparation, the stirring speed is set to 210 r / min and the stirring time is 11 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 0.8 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 3800 r / min, the centrifugal force at 28 g, and the backwash water flow rate at 5.2 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 8.6% WO3 and 1.3% Mo, and the scavenging tailings contain 0.26% WO3 and 0.14% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:3.8. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 23% and returned to the second stage cleaning process for recycling and enrichment.

[0108] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 91.0%, and the molybdenum metal recovery rate was 84.0%.

[0109] Example 15 In this embodiment, the ammonium paratungstate metallurgical slag contains 4.2% tungsten trioxide (WO3), 1.5% molybdenum (Mo), and 17% moisture. The original particle size is no more than 50 mm, and the speed of the Nelson centrifugal concentrator is 4600 r / min.

[0110] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. 30mm diameter steel balls are used as grinding media during the grinding process, with a ball-to-material mass ratio of 5:1 and a grinding time of 82 minutes. After grinding, the proportion of -0.074mm particles in the grinding product is controlled to be 86%, ensuring full dissociation of tungsten and molybdenum minerals from gangue minerals. The qualified grinding material is then slurried with clean water, and the slurry concentration is controlled to be 36%. Sodium hexametaphosphate is added to the slurry as a dispersant, with an addition amount of 0.05% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started, with a stirring speed of 290 r / min and a stirring time of 21 minutes, to fully disperse the slurry, eliminate fine mud agglomeration, and ensure uniform and stable slurry.

[0111] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 1000 mm and 5 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 26 r / min, the slurry flow rate is 1.3 m / s, and the slurry feed rate is 1.8 m / s. 3 The separation environment temperature is controlled at 28℃ per hour. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 20%, and the rougher tailings contain 0.34% WO3 and 0.13% Mo, which are directly discarded.

[0112] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 28%. During the slurry treatment, the stirring speed is set to 290 r / min and the stirring time is 17 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.6 m and a bed width of 1.4 m. During the separation process, the shaking table stroke is controlled at 18 mm, the stroke rate is 360 times / min, and the transverse slope is 2.9°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 40.8%, the Mo grade is 5.7%, and the yield of clean middlings is 16%.

[0113] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 36%. During the slurry preparation, the stirring speed is set to 290 r / min and the stirring time is 17 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.3 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4600 r / min, the centrifugal force at 42 g, and the backwash water flow rate at 6.6 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 10.2% WO3 and 1.8% Mo, while the scavenging tailings contain 0.19% WO3 and 0.08% Mo, and are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.6. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 27% and returned to the second stage cleaning process for recycling and enrichment.

[0114] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 94.8%, and the molybdenum metal recovery rate was 88.5%.

[0115] Example 16 The ammonium paratungstate metallurgical slag used in this embodiment contains 2.8% tungsten trioxide (WO3), 1.1% molybdenum (Mo), and 13% moisture content. The original particle size is no more than 50 mm, and the transverse slope of the double-layer shaking table is 2.3°.

[0116] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 22 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 4.2:1 and the grinding time is set at 65 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 78% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 31%. A mixed dispersant of sodium polyacrylate and sodium hexametaphosphate with a mass ratio of 1:1 is added to the slurry. The amount of dispersant added is 0.03% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 230 r / min and the stirring time is 17 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0117] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The spiral diameter of the selected spiral chute is 850 mm, and the number of spiral turns is 4. During the separation process, the spindle speed of the spiral chute is controlled at 23 r / min, the slurry flow rate is 1.2 m / s, and the slurry feed rate is 1.6 m / s. 3 The separation environment temperature is controlled at 23℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 17%, and the rougher tailings contain 0.41% WO3 and 0.16% Mo, which are directly discarded.

[0118] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 25%. During the slurry treatment, the stirring speed is set to 240 r / min and the stirring time is 13 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.3 m and a bed width of 1.2 m. During the separation process, the shaking table stroke is controlled at 16 mm, the stroke rate is 330 times / min, and the transverse slope is 2.3°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 38.5%, the Mo grade is 5.1%, and the yield of clean middlings is 13%.

[0119] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 33%. During the slurry preparation, the stirring speed is set to 240 r / min and the stirring time is 13 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.0 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4100 r / min, the centrifugal force at 33 g, and the backwash water flow rate at 5.7 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 9.3% WO3 and 1.5% Mo, and the scavenging tailings contain 0.23% WO3 and 0.12% Mo, which are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.1. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 25% and returned to the second stage cleaning process for recycling and enrichment.

[0120] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 92.5%, and the molybdenum metal recovery rate was 86.0%.

[0121] Example 17 In this embodiment, the ammonium paratungstate metallurgical slag contains 5.0% tungsten trioxide (WO3), 1.7% molybdenum (Mo), 18% moisture, and an original particle size of no more than 50 mm. The ball milling time is 88 min.

[0122] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 30 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 5:1 and the grinding time is set to 88 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 89% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 39%. A mixed dispersant with a mass ratio of sodium polyacrylate and sodium hexametaphosphate of 3:2 is added to the slurry. The amount of dispersant added is 0.05% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set to 300 r / min and the stirring time is 24 min to fully disperse the slurry, eliminate fine mud agglomeration, and ensure that the slurry is uniform and stable.

[0123] (2) First-stage roughing: The pretreated, uniform and stable slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 1150 mm and 5 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 27 r / min, the slurry flow rate is 1.4 m / s, and the slurry feed rate is 1.9 m / s. 3 The separation environment temperature is controlled at 32℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 21%, and the rougher tailings contain 0.33% WO3 and 0.12% Mo, which are directly discarded.

[0124] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration after slurry treatment is controlled at 29%. During the slurry treatment, the stirring speed is set to 310 r / min and the stirring time is 17 min to ensure that the slurry is evenly dispersed and free of agglomeration. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 2.7 m and a bed width of 1.4 m. During the separation process, the shaking table stroke is controlled at 19 mm, the stroke rate is 370 times / min, and the transverse slope is 3.3°. After separation by the double-layer shaking table, clean concentrate and clean middlings are obtained. The WO3 grade in the clean concentrate is 41.5%, the Mo grade is 5.9%, and the yield of clean middlings is 17%.

[0125] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 37%. During the slurry preparation, the stirring speed is set to 310 r / min and the stirring time is 17 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 1.4 m³. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 4900 r / min, the centrifugal force at 48 g, and the backwash water flow rate at 7.2 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 10.8% WO3 and 1.9% Mo, while the scavenging tailings contain 0.16% WO3 and 0.07% Mo, and are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:4.9. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 27% and returned to the second stage cleaning process for recycling and enrichment.

[0126] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 95.8%, and the molybdenum metal recovery rate was 89.8%.

[0127] Example 18 In this embodiment, the ammonium paratungstate metallurgy used contains 1.2% tungsten trioxide (WO3), 0.5% molybdenum (Mo), and 9% moisture. The original particle size is no greater than 50 mm, and the initial temperature of the sorting environment is 14°C.

[0128] (1) Raw material pretreatment: The above-mentioned ammonium paratungstate metallurgical slag is first crushed and then fed into a grate ball mill for grinding. Steel balls with a diameter of 12 mm are used as grinding media during the grinding process. The ball-to-material mass ratio is controlled at 3.2:1 and the grinding time is set at 35 min. After grinding, the proportion of -0.074 mm particles in the grinding product is controlled at 68% to ensure that tungsten and molybdenum minerals are fully liberated from gangue minerals. The material after grinding is slurryed with clean water. The slurry mass concentration is controlled at 26%. Sodium polyacrylate is added to the slurry as a dispersant. The amount of dispersant added is 0.01% of the dry basis mass of the metallurgical slag. After adding the dispersant, the stirring device is started. The stirring speed is set at 160 r / min and the stirring time is 11 min to fully disperse the slurry and eliminate fine mud agglomeration. Since the ambient temperature is below 15℃, the slurry is heated and kept warm to control the slurry temperature at 20℃ to ensure good slurry fluidity.

[0129] (2) First-stage roughing: The pretreated, uniform, and temperature-controlled slurry is fed into a fiberglass spiral chute for roughing. The selected spiral chute has a spiral diameter of 650 mm and 3 spiral turns. During the separation process, the main shaft speed of the spiral chute is controlled at 19 r / min, the slurry flow rate is 0.9 m / s, and the slurry feed rate is 1.3 m / s. 3 The separation environment temperature is controlled at 20℃. After separation by spiral chute, rougher concentrate and rougher tailings are obtained; the rougher concentrate yield is 13%, and the rougher tailings contain 0.49% WO3 and 0.19% Mo. The valuable metal content of the rougher tailings is extremely low, and they are directly discarded.

[0130] (3) Second-stage cleaning: The rough concentrate obtained from the first-stage roughing is treated with clean water to form a slurry. The slurry concentration is controlled at 21% after slurry treatment. During the slurry treatment, the stirring speed is set to 190 r / min and the stirring time is 9 min to ensure that the slurry is evenly dispersed and free of agglomeration, meeting the requirements of shaking table separation. The qualified slurry is sent to a double-layer shaking table for cleaning. The selected double-layer shaking table has a bed length of 1.9 m and a bed width of 0.9 m. During the separation process, the shaking table stroke is controlled at 13 mm, the stroke rate is 290 times / min, and the transverse slope is 1.6°. After separation by the double-layer shaking table, the cleaned concentrate (i.e., tungsten-molybdenum mixed concentrate) and cleaned middlings are obtained. The WO3 grade in the cleaned concentrate is 35.5%, and the Mo grade is 4.6%, meeting the requirements for subsequent deep processing raw materials. The yield of the cleaned middlings is 9%, containing a certain amount of unrecovered tungsten and molybdenum minerals, which need to be further separated and recovered.

[0131] (4) Three-stage scavenging: The middlings obtained from the two-stage scavenging are treated with clean water to form a slurry with a concentration of 29%. During the slurry preparation process, the stirring speed is set to 190 r / min and the stirring time is 9 min to ensure uniform dispersion and good fluidity of the slurry. The slurry after scavenging is sent to a Nelson centrifugal concentrator for scavenging. The capacity of the selected Nelson centrifugal concentrator is 0.6 m³ / min. 3 / h; During the separation process, the centrifugal concentrator speed is controlled at 3200 r / min, the centrifugal force is 22g (g is the acceleration due to gravity), and the backwash water flow rate is 4.8 L / min. After separation by the Nelson centrifugal concentrator, scavenging concentrate and scavenging tailings are obtained; the scavenging concentrate contains 8.2% WO3 and 1.2% Mo, while the scavenging tailings contain 0.28% WO3 and 0.14% Mo. The scavenging tailings have extremely low valuable metal content and are directly discarded. The obtained scavenging concentrate is mixed with the roughing concentrate obtained from the first stage roughing at a mass ratio of 1:3.2. After mixing, the slurry is adjusted with clean water to a slurry mass concentration of 22% and returned to the second stage cleaning process. It is then fed into a double-layer shaking table together with the roughing concentrate for circulating enrichment to improve the recovery rate of tungsten and molybdenum metals.

[0132] According to atomic absorption spectrophotometry, the tungsten metal recovery rate in this embodiment was 90.0%, and the molybdenum metal recovery rate was 83.0%.

Claims

1. A three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag, characterized in that, Includes the following steps: S1: Raw material pretreatment: crush and grind the ammonium paratungstate metallurgical slag, and control the grinding fineness to 65%-90% of the particles with a particle size of -0.074mm; after grinding, adjust the slurry to a mass concentration of 25%-40%, add 0.01%-0.05% of the metallurgical slag mass of dispersant, and stir evenly. S2: First stage roughing: The pretreated slurry is fed into the spiral chute for roughing, with the rotation speed controlled at 18-28 r / min, the slurry flow rate at 0.8-1.5 m / s, and the separation temperature at 15-35℃, to obtain roughing concentrate and roughing tailings. The roughing tailings are directly discarded. S3: Second stage of cleaning: The rougher concentrate is slurry adjusted to a mass concentration of 20%-30% and sent to a shaking table for cleaning. The stroke is controlled at 12-20mm, the stroke rate at 280-380 times / min, and the transverse slope at 1.5°-3.5° to obtain tungsten-molybdenum mixed concentrate and middlings. S4: Three-stage scavenging: The middlings are slurry adjusted to a mass concentration of 28%-38% and fed into a centrifugal concentrator for scavenging. The rotation speed is controlled at 3000-5000 r, the centrifugal force at 20-50 g, and the backwash water flow rate at 4.5-7.5 L / min to obtain scavenged concentrate and scavenged tailings. The scavenged tailings are discarded, and the scavenged concentrate is returned to the second-stage scavenging cycle. The ammonium paratungstate metallurgical slag is ammonium paratungstate alkaline boiling slag with an original particle size ≤50mm, a moisture content of 8%-18%, and contains WO3 1.0%-5.5% and Mo 0.4%-1.8%. Tungsten is found in scheelite, molybdenum in molybdenite, and gangue is fluorapatite, calcite, and sparstone.

2. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The S1 dispersant is one or both of sodium polyacrylate and sodium hexametaphosphate, and the stirring speed is 150-300 r / min and the stirring time is 10-25 min.

3. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The S1 grinding process uses a ball mill with steel balls of 10-30 mm in diameter, a ball-to-material ratio of 3-5:1, and a grinding time of 30-90 min.

4. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The S2 spiral chute has a diameter of 600-1200mm, 3-5 turns, and a feed rate of 1.2-2.0m / s. 3 / h; roughing concentrate yield 12%-22%, tailings WO3≤0.5%, Mo≤0.2%.

5. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The S3 shaking table is a double-layered table with a length of 1.8-2.8m and a width of 0.8-1.5m; the concentrate has WO3 ≥ 35.0%, Mo ≥ 4.5%, and a middlings yield of 8%-18%.

6. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The S4 centrifugal concentrator is a Nelson type with a processing capacity of 0.5-1.5m³. 3 / h; scavenged concentrate WO3≥8.0%, Mo≥1.2%, tailings WO3≤0.3%, Mo≤0.15%.

7. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 6, characterized in that, In S2 to S4, clean water is used for slurry preparation, and the stirring speed is 180-320 r / min and the time is 8-18 min.

8. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The sorting temperature is 20-30℃; when the ambient temperature is <15℃, the ore is heated to ≤35℃.

9. The three-stage gravity separation enrichment process for tungsten and molybdenum from ammonium paratungstate metallurgical slag according to claim 1, characterized in that, The scavenging concentrate and roughing concentrate are mixed at a ratio of 1:3 to 1:5, and the concentration after mixing is 22% to 28%, which is then returned to the cleaner.

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