Method for recovering tungsten, silver and gallium from wolframite-containing ore

Abstract

The invention provides a method for recovering tungsten, silver and gallium from wolframite-containing ore, which is based on the weak magnetic property of wolframite, integrates the coordination of multiple processes of strong magnetic pre-enrichment, weak magnetic separation iron removal, tungsten extraction by flotation, silver-sulfur flotation and gallium extraction by roasting and acid leaching, and realizes the efficient separation and recovery of tungsten, silver and gallium in wolframite-containing ore. The defects that in the prior art, pre-enrichment of wolframite is insufficient, flotation is interfered by iron impurities, silver-sulfur minerals are lost, and the gallium leaching efficiency is low are overcome.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive recovery technology of mineral resources, and relates to a method for recovering tungsten, silver and gallium from wolframite ore. Background Technology

[0002] Wolframite, a core raw material in the tungsten industry, contains associated silver (often in the form of silver sulfide) and gallium (mostly found in aluminosilicate minerals), which have extremely high economic value. Current wolframite recovery processes face two major contradictions: first, traditional magnetic separation processes are only used for simple impurity removal, failing to fully utilize the weak magnetic properties of wolframite for pre-enrichment, leading to excessive processing volumes in subsequent tungsten extraction steps; second, existing processes often place silver and gallium recovery at the end of tungsten recovery, lacking targeted flotation processes, resulting in the loss of silver and sulfide minerals, while gallium leaching efficiency is significantly affected by the ore matrix.

[0003] In existing technologies, some processes directly extract tungsten from the raw ore through flotation. However, due to interference from magnetic impurities (such as magnetite) and gangue minerals in the ore, a large amount of modifiers needs to be added, which not only increases costs but also makes it difficult to break through 65% in tungsten concentrate grade. Other processes use a single acid leaching treatment on the tailings after tungsten recovery. Because silver-sulfur minerals are not pre-flotated and enriched, the leaching rate is less than 70%, and gallium, without roasting and activation, has an acid leaching rate of only 60%-65%. Furthermore, the lack of a connection between strong and weak magnetic separation results in residual iron impurities affecting the selectivity of subsequent flotation reagents, further reducing the recovery rate of valuable metals.

[0004] Therefore, considering the weak magnetic properties of wolframite, constructing an integrated process of "pre-enrichment-de-targeted flotation-roasting leaching" has become a key technological direction for solving the problems of low efficiency and high cost in the comprehensive recovery of tungsten, silver, and gallium. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for recovering tungsten, silver and gallium from wolframite ore, which addresses the shortcomings of the prior art. This method is based on the weak magnetic properties of wolframite and integrates multiple processes such as strong magnetic pre-enrichment, weak magnetic separation for iron removal, flotation for tungsten extraction, silver-sulfur flotation, and roasting and acid leaching for gallium extraction, so as to achieve efficient separation and recovery of tungsten, silver and gallium from wolframite ore.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for recovering tungsten, silver, and gallium from wolframite ore, comprising the following steps: S1, Ore Pretreatment The wolframite ore is coarsely crushed and then medium crushed and ball-milled. The particle size of the ore after grinding is controlled to be -200 mesh, accounting for 80%-90%. Then water is added to adjust the slurry concentration to 30%-35% to obtain the pretreated slurry. S2, strong magnetic pre-enrichment The pretreated slurry obtained from S1 was subjected to strong magnetic separation at room temperature to enrich wolframite, with the magnetic field strength controlled at 18000-22000 Gs and the slurry flow rate at 1.5-2.0 m / s. 3 The flushing water pressure is 0.2-0.4 MPa per hour, yielding wolframite concentrate and strongly magnetic tailings. S3, Weak magnetic separation for iron removal The wolframite rough concentrate obtained from S2 was subjected to weak magnetic separation at room temperature, with the magnetic field strength controlled at 3000-5000 Gs, the pulp concentration adjusted to 25%-30%, and the magnetic separation time at 8-12 min, to obtain low-iron wolframite rough concentrate and iron concentrate. S4, Tungsten extraction by flotation Take the low-iron wolframite rough concentrate obtained from S3, adjust the pH of the pulp to 8-9, add the collector benzohydroxyxamic acid, the inhibitor water glass and the activator aluminum sulfate, stir at room temperature for 3-5 minutes and then carry out flotation. The flotation adopts the "one roughing, two cleaning and one scavenging" process: roughing time 8-10 minutes, cleaning time 5-6 minutes, scavenging time 6-8 minutes, water glass 300-500 g / t is added during cleaning, and finally tungsten concentrate and tungsten flotation tailings are obtained. S5, silver-sulfur flotation Take the strong magnetic tailings obtained from S2, adjust the pulp concentration to 28%-32%, adjust the pulp pH to 9-10, add the collector butyl xanthate, the frother No. 2 oil and the inhibitor lime, stir at room temperature for 2-3 minutes and then carry out silver-sulfur flotation. The flotation process is "one roughing and one cleaning": the roughing time is 6-8 minutes and the cleaning time is 4-5 minutes, to obtain silver-sulfur rough concentrate and silver-sulfur flotation tailings. S6, Calcination-acid leaching gallium The silver-sulfur flotation tailings obtained from S5 were roasted at 750-850℃ for 3-4 hours, with oxygen introduced during roasting, to obtain the roasted product. The roasted product was added to a 20%-25% hydrochloric acid solution with a liquid-to-solid ratio of 6:1, and leached with stirring at 80-90℃ for 2-3 hours, with 0.5%-1.0% sodium chloride added during leaching, to obtain a gallium-containing leachate. Aluminum hydroxide was added to the gallium-containing leachate to adjust the pH to 3-4, and precipitation was allowed for 1-1.5 hours. The purified gallium-containing leachate was then obtained by filtration. The purified gallium-containing liquid was extracted using N235 extractant with a volume fraction of 10%-15% at an extraction ratio of 1:3-1:5 and a shaking time of 15-20 min to obtain a supported organic phase. The supported organic phase was back-extracted using hydrochloric acid solution with a concentration of 1.5-2.0 mol / L at a back-extraction ratio of 2:1-3:1 to obtain a back-extraction solution. The back-extraction solution was evaporated, concentrated, and crystallized to obtain gallium chloride crystals, which were then reduced and calcined at 550-650℃ for 2-3 h in a hydrogen atmosphere to obtain metallic gallium.

[0007] Preferably, the particle size after coarse crushing in S1 is ≤50mm, and the particle size after medium crushing is ≤10mm.

[0008] Preferably, sodium carbonate is used to adjust the pH value of the slurry in S4; the amount of the collector benzohydroxyxamic acid is 100-150 g / t, the amount of the inhibitor water glass is 800-1200 g / t, and the amount of the activator aluminum sulfate is 200-300 g / t.

[0009] The WO3 grade of the tungsten concentrate obtained by S4 of this invention is ≥70%, and the recovery rate is ≥92%.

[0010] Preferably, sodium hydroxide is used to adjust the pH value of the slurry in S5; the amount of butyl xanthate collector is 80-120 g / t, the amount of No. 2 oil foaming agent is 20-30 g / t, and the amount of lime inhibitor is 500-800 g / t.

[0011] The silver grade of the silver-sulfur crude concentrate obtained by S5 of this invention is ≥1500g / t, and the recovery rate is ≥85%.

[0012] Preferably, the oxygen flow rate during the roasting process in S6 is 5-8 m³ / h. 3 / h.

[0013] Preferably, the temperature for evaporating and concentrating the back-extraction solution in step S6 is 80-90°C, and the crystallization time is 4-6 hours; the flow rate of hydrogen is 6-8 m³ / h. 3 / h.

[0014] The purity of the gallium metal obtained in S6 of this invention is ≥99.9%, and the recovery rate is ≥82%.

[0015] This invention has significant technical advantages compared to existing technologies: This invention overcomes the shortcomings of existing processes, such as insufficient pre-enrichment of wolframite, interference of iron impurities with flotation, loss of silver-sulfur minerals, and low gallium leaching efficiency. It provides a process method based on a synergistic approach of strong magnetic pre-enrichment, weak magnetic separation for iron removal, flotation, and roasting, which has the following advantages: (1) High pre-enrichment efficiency: In response to the weak magnetic characteristics of wolframite, strong magnetic separation of 18000-22000Gs is used to achieve pre-enrichment, the recovery rate of wolframite rough concentrate is ≥88%, the subsequent flotation processing volume is reduced by more than 60%, and energy consumption is greatly saved.

[0016] (2) Precise removal of iron impurities: Weak magnetic separation is used to remove iron impurities, so that the iron content of the black tungsten concentrate is ≤1.5%, which improves the selectivity of flotation reagents and the grade of tungsten concentrate reaches more than 70%, which is 5%-8% higher than the traditional process.

[0017] (3) Targeted recovery of silver and sulfur minerals: targeted flotation of silver and sulfur in strong magnetic tailings, with a silver recovery rate of ≥85%, avoiding the loss of silver in the traditional acid leaching process and reducing the cost of silver extraction by 30%.

[0018] (4) Improved gallium leaching efficiency: After roasting and activation (destroying the lattice of gallium-containing minerals) and hydrochloric acid-sodium chloride leaching, the gallium leaching rate is ≥85%, which is 20%-25% higher than direct acid leaching, and the final gallium metal recovery rate is ≥82%.

[0019] (5) Strong process synergy: Each process forms a closed loop of "pre-enrichment-removal-flotation-roasting leaching", with no secondary pollution, and the iron concentrate can be recovered as a by-product, increasing the resource utilization rate to over 90%.

[0020] The following embodiments further illustrate the present invention in detail. Detailed Implementation

[0021] This invention provides a process for recovering tungsten, silver, and gallium from wolframite ore, comprising the following steps: S1, Ore Pretreatment Wolframite ore is coarsely crushed (≤50mm) by a jaw crusher and medium crushed (≤10mm) by a cone crusher, then fed into a ball mill for grinding. The ore particle size after grinding is controlled to be 80%-90% of -200 mesh. Water is added to adjust the slurry concentration to 30%-35%, resulting in a pretreated slurry. This particle size range ensures that the liberation degree of wolframite is ≥85%, meeting the requirements of subsequent high-intensity magnetic separation.

[0022] S2, strong magnetic pre-enrichment The pretreated slurry obtained from S1 is fed into a high-gradient magnetic separator, with the magnetic field strength controlled at 18000-22000 Gs (for the weakly magnetic characteristics of wolframite), and the slurry flow rate at 1.5-2.0 m / s. 3 The washing water pressure is 0.2-0.4 MPa, and strong magnetic separation is carried out at room temperature. Wolframite is recovered through strong magnetic action to obtain wolframite rough concentrate (tungsten grade ≥25%, recovery rate ≥88%) and strong magnetic tailings (containing silver-sulfur minerals, gallium and gangue), thus achieving pre-enrichment of wolframite and reducing the amount of subsequent processing.

[0023] S3, Weak magnetic separation for iron removal The wolframite rough concentrate obtained from S2 is fed into a permanent magnet drum-type weak magnetic separator. The magnetic field strength is controlled at 3000-5000 Gs (for strongly magnetic iron impurities), the pulp concentration is adjusted to 25%-30%, and the magnetic separation time is 8-12 minutes. Weak magnetic separation is carried out at room temperature. This removes iron impurities such as magnetite and hematite from the rough concentrate, yielding low-iron wolframite rough concentrate (iron content ≤1.5%) and iron concentrate (iron grade ≥60%, which can be recovered as a by-product), thus avoiding interference from iron impurities in subsequent flotation.

[0024] S4, Tungsten extraction by flotation The low-iron wolframite rough concentrate obtained from S3 is fed into a flotation cell. The pH of the pulp is adjusted to 8-9 (using sodium carbonate as a solid adjuster). A reagent combination is added: collector benzohydroxyxamic acid (100-150 g / t), inhibitor water glass (800-1200 g / t), and activator aluminum sulfate (200-300 g / t). After stirring at room temperature for 3-5 minutes, flotation is carried out. The flotation adopts a "one roughing, two cleaning, one scavenging" process: roughing time is 8-10 minutes, cleaning time is 5-6 minutes (water glass is added during cleaning) and scavenging time is 6-8 minutes. Finally, tungsten concentrate (WO3 grade ≥70%, recovery rate ≥92%) and tungsten flotation tailings (containing trace amounts of tungsten and gangue) are obtained.

[0025] S5, silver-sulfur flotation Take the strongly magnetic tailings obtained from S2, adjust the pulp concentration to 28%-32% and the pH value to 9-10 (using solid sodium hydroxide for adjustment), add butyl xanthate collector (80-120 g / t), frother No. 2 oil (20-30 g / t), and depressant lime (500-800 g / t, to suppress gangue), stir at room temperature for 2-3 minutes, and then carry out silver-sulfur flotation. The flotation process is "one roughing and one cleaning": roughing time 6-8 minutes, cleaning time 4-5 minutes, to obtain silver-sulfur rough concentrate (silver grade ≥1500 g / t, recovery rate ≥85%) and silver-sulfur flotation tailings (containing gallium and gangue).

[0026] S6, Calcination-acid leaching gallium The silver-sulfur flotation tailings obtained from S5 are fed into a rotary kiln and roasted at 750-850℃ for 3-4 hours (roasting can destroy the crystal lattice of gallium-containing minerals and activate gallium). Oxygen is introduced during the roasting process (flow rate 5-8 m³ / h). 3 / h), to obtain the calcined product; add the calcined product to a 20%-25% hydrochloric acid solution with a liquid-to-solid ratio of 6:1, and stir and leach at 80-90℃ for 2-3h, adding 0.5%-1.0% sodium chloride (as a gallium leaching aid) during the leaching process to obtain a gallium-containing leachate; add aluminum hydroxide solid to the gallium-containing leachate to adjust the pH to 3-4, precipitate for 1-1.5h to remove impurities such as iron and aluminum, and filter to obtain a purified gallium-containing solution; use a 10%- volume fraction of hydrochloric acid solution to leach the gallium-containing solution. The purified gallium-containing solution was extracted with 15% N235 extractant at an extraction ratio of 1:3-1:5 (organic phase:aqueous phase) and a shaking time of 15-20 min to obtain a loaded organic phase. The loaded organic phase was then back-extracted with a 1.5-2.0 mol / L hydrochloric acid solution at an extraction ratio of 2:1-3:1 to obtain a back-extract. The back-extract was then concentrated by evaporation (80-90℃) and crystallized (4-6 h) to obtain gallium chloride crystals. These crystals were then purified under a hydrogen atmosphere (flow rate 6-8 m³ / h). 3Reduced and roasted at 550-650℃ for 2-3 hours to obtain metallic gallium (purity ≥99.9%, recovery rate ≥82%).

[0027] The following detailed description is provided through specific embodiments.

[0028] The wolframite ore used in the following examples has the same composition: WO3 grade 3.2%, silver grade 180 g / t, gallium grade 65 × 10⁻ 6 It also contains iron impurities such as magnetite and hematite (total iron content 8.5%), and the gangue minerals are mainly quartz and feldspar.

[0029] Example 1 This embodiment describes a method for recovering tungsten, silver, and gallium from wolframite ore, including the following steps: S1. Ore pretreatment: The wolframite ore is coarsely crushed and then ball-milled. The particle size of the ore after grinding is controlled to be -200 mesh, accounting for 85%. The slurry concentration is adjusted to 32% to obtain pretreated slurry.

[0030] S2. High-intensity magnetic pre-enrichment: The pretreated slurry is fed into a high-gradient high-intensity magnetic separator with a magnetic field strength of 20,000 Gs and a slurry flow rate of 1.8 m / s. 3 At a flow rate of 0.3 MPa and a washing water pressure of 0.3 MPa, magnetic separation at room temperature yielded wollastonite rough concentrate (WO3 grade 28.5%, recovery rate 89.2%) and strongly magnetic tailings.

[0031] S3. Weak magnetic separation for iron removal: The wolfram concentrate is fed into a permanent magnet drum-type weak magnetic separator with a magnetic field strength of 4000 Gs, a pulp concentration of 28%, and a magnetic separation time of 10 min. The magnetic separation is carried out at room temperature to obtain low-iron wolfram concentrate (iron content 1.2%) and iron concentrate (iron grade 62.5%).

[0032] S4. Tungsten extraction by flotation: Adjust the pH of the low-iron wolframite concentrate pulp to 8.5, add 120 g / t of benzohydroxyxamic acid, 1000 g / t of water glass, and 250 g / t of aluminum sulfate. After stirring for 4 minutes, use the "one roughing, two cleaning, and one scavenging" process for flotation. Roughing for 9 minutes, cleaning for 5.5 minutes (with the addition of 400 g / t of water glass), and scavenging for 7 minutes to obtain tungsten concentrate (WO3 grade 72.3%, recovery rate 93.5%).

[0033] S5. Silver-sulfur flotation: Take strong magnetic tailings and adjust the pulp concentration to 30% and pH value to 9.5. Add 100g / t of butyl xanthate, 25g / t of No. 2 oil and 650g / t of lime. Stir for 2.5min and then perform "one roughing and one cleaning" flotation. Roughing takes 7min and cleaning takes 4.5min to obtain silver-sulfur rough concentrate (silver grade 1680g / t, recovery rate 86.8%).

[0034] S6. Roasting-Acid Leaching for Gallium Extraction: The silver-sulfur flotation tailings are fed into a rotary kiln and roasted at 780℃ for 3.5 hours, with an oxygen flow rate of 6.5 m³ / h. 3 / h; the calcined product was added to a 22% hydrochloric acid solution (liquid-solid ratio 6:1), stirred and leached at 85℃ for 2.5h, and then 0.8% sodium chloride was added; the pH of the leachate was adjusted to 3.5 with aluminum hydroxide, and after precipitation for 1.2h, it was filtered; 12% volume fraction N235 extractant was used, with an extraction ratio of 1:4, and shaken for 18min; back-extracted with 1.8mol / L hydrochloric acid solution (ratio 2.5:1), the back-extracted solution was evaporated and concentrated at 85℃, and crystallized for 5h to obtain gallium chloride crystals, which were then crystallized in a hydrogen atmosphere (flow rate 7m). 3 Reduction calcination at 600℃ for 2.5 h yielded metallic gallium (purity 99.93%, recovery rate 83.6%).

[0035] Example 2 This embodiment describes a method for recovering tungsten, silver, and gallium from wolframite ore, including the following steps: S1. Ore pretreatment: The wolframite ore is coarsely crushed and then ball-milled. The particle size of the ore after grinding is controlled to be 80% of -200 mesh, and the slurry concentration is adjusted to 30% to obtain pretreated slurry.

[0036] S2. High-intensity magnetic pre-enrichment: The pretreated slurry is fed into a high-gradient high-intensity magnetic separator with a magnetic field strength of 18000 Gs and a slurry flow rate of 1.5 m / s. 3 At a flow rate of 0.2 MPa and a washing water pressure of 0.2 MPa, magnetic separation at room temperature yielded wollastonite rough concentrate (WO3 grade 25.3%, recovery rate 88.1%) and strongly magnetic tailings.

[0037] S3. Weak magnetic separation for iron removal: The wolfram concentrate is fed into a permanent magnet drum-type weak magnetic separator with a magnetic field strength of 3000 Gs, a pulp concentration of 25%, and a magnetic separation time of 8 min. The magnetic separation is carried out at room temperature to obtain low-iron wolfram concentrate (iron content 1.4%) and iron concentrate (iron grade 60.8%).

[0038] S4. Tungsten extraction by flotation: Adjust the pH of the low-iron wolframite concentrate pulp to 8.0, add 100g / t of benzohydroxyxamic acid, 800g / t of water glass, and 200g / t of aluminum sulfate. After stirring for 3 minutes, use the "one roughing, two cleaning, and one scavenging" process for flotation: roughing for 8 minutes, cleaning for 5 minutes (adding 300g / t of water glass), and scavenging for 6 minutes to obtain tungsten concentrate (WO3 grade 70.5%, recovery rate 92.1%).

[0039] S5. Silver-sulfur flotation: Take strong magnetic tailings and adjust the pulp concentration to 28% and pH value to 9.0. Add 80g / t of butyl xanthate, 20g / t of No. 2 oil and 500g / t of lime. After stirring for 2 minutes, perform "one roughing and one cleaning" flotation. Roughing takes 6 minutes and cleaning takes 4 minutes to obtain silver-sulfur rough concentrate (silver grade 1520g / t, recovery rate 85.2%).

[0040] S6. Roasting-Acid Leaching for Gallium Extraction: The silver-sulfur flotation tailings are fed into a rotary kiln and roasted at 750℃ for 3 hours, with an oxygen flow rate of 5 m³ / h. 3 / h; the calcined product was added to a 20% hydrochloric acid solution (liquid-solid ratio 6:1), stirred and leached at 80℃ for 2h, and then 0.5% sodium chloride was added; the pH of the leachate was adjusted to 3.0 with aluminum hydroxide, and after precipitation for 1h, it was filtered; 10% volume fraction N235 extractant was used, with an extraction ratio of 1:3, and shaken for 15min; back-extracted with 1.5mol / L hydrochloric acid solution (ratio 2:1), the back-extracted solution was evaporated and concentrated at 80℃, and crystallized for 4h to obtain gallium chloride crystals, which were then subjected to a hydrogen atmosphere (flow rate 6m³ / h). 3 Reduction calcination at 550℃ for 2 hours yielded metallic gallium (purity 99.91%, recovery rate 82.0%).

[0041] Example 3 This embodiment describes a method for recovering tungsten, silver, and gallium from wolframite ore, including the following steps: S1. Ore pretreatment: The wolframite ore is coarsely crushed and then ball-milled. The particle size of the ore after grinding is controlled to be 90% -200 mesh, and the slurry concentration is adjusted to 35% to obtain pretreated slurry.

[0042] S2. High-intensity magnetic pre-enrichment: The pretreated slurry is fed into a high-gradient high-intensity magnetic separator with a magnetic field strength of 122,000 Gs and a slurry flow rate of 2.0 m / s. 3 At a flow rate of 0.4 MPa and a washing water pressure of 0.4 MPa, magnetic separation at room temperature yielded wollastonite rough concentrate (WO3 grade 30.2%, recovery rate 90.5%) and strongly magnetic tailings.

[0043] S3. Weak magnetic separation for iron removal: The wolfram concentrate is fed into a permanent magnet drum-type weak magnetic separator with a magnetic field strength of 5000 Gs, a pulp concentration of 30%, and a magnetic separation time of 12 min. The magnetic separation is carried out at room temperature to obtain low-iron wolfram concentrate (iron content 1.0%) and iron concentrate (iron grade 63.8%).

[0044] S4. Tungsten extraction by flotation: Adjust the pH of the low-iron wolframite concentrate pulp to 9.0, add 150 g / t of benzohydroxyxamic acid, 1200 g / t of water glass, and 300 g / t of aluminum sulfate. After stirring for 5 minutes, use the "one roughing, two cleaning, and one scavenging" process for flotation: roughing for 10 minutes, cleaning for 6 minutes (adding 500 g / t of water glass), and scavenging for 8 minutes to obtain tungsten concentrate (WO3 grade 73.8%, recovery rate 94.2%).

[0045] S5. Silver-sulfur flotation: Take strong magnetic tailings and adjust the pulp concentration to 32% and pH value to 10.0. Add 120g / t of butyl xanthate, 30g / t of No. 2 oil and 800g / t of lime. After stirring for 3 minutes, perform "one roughing and one cleaning" flotation. Roughing takes 8 minutes and cleaning takes 5 minutes to obtain silver-sulfur rough concentrate (silver grade 1750g / t, recovery rate 87.6%).

[0046] S6. Roasting-Acid Leaching for Gallium Extraction: The silver-sulfur flotation tailings are fed into a rotary kiln and roasted at 850℃ for 4 hours, with an oxygen flow rate of 8 m³ / h. 3 / h; the calcined product was added to a 25% hydrochloric acid solution (liquid-solid ratio 6:1), stirred and leached at 90℃ for 3h, and then 1.0% sodium chloride was added; the pH of the leachate was adjusted to 4.0 with aluminum hydroxide, and after precipitation for 1.5h, it was filtered; 15% volume fraction N235 extractant was used, with an extraction ratio of 1:5, and shaken for 20min; back-extracted with 2.0mol / L hydrochloric acid solution (ratio 3:1), the back-extracted solution was evaporated and concentrated at 90℃, and crystallized for 6h to obtain gallium chloride crystals, which were then subjected to a hydrogen atmosphere (flow rate 8m³ / h). 3 Reduction calcination at 650℃ for 3 hours yielded metallic gallium (purity 99.95%, recovery rate 84.8%).

[0047] Comparative Example 1 The traditional direct flotation process without pre-enrichment involves the following steps: (1) Ore pretreatment: Same as in Example 1, to obtain pretreated slurry with the same particle size and concentration.

[0048] (2) Direct flotation for tungsten extraction: without strong magnetic pre-enrichment and weak magnetic separation for iron removal, the pH of the pulp is directly adjusted to 8.5, and 200 g / t of benzohydroxyxamic acid, 1800 g / t of water glass and 400 g / t of aluminum sulfate are added (the amount of reagents is increased due to iron impurities and gangue interference). After stirring for 4 minutes, the same flotation process is used to obtain tungsten concentrate (WO3 grade 63.8%, recovery rate 82.5%).

[0049] (3) Tailings treatment: Silver and gallium were extracted directly from the flotation tailings by acid leaching with 22% hydrochloric acid solution under the same leaching conditions as in Example 1. The silver leaching rate was 68.3%, the gallium leaching rate was 62.1%, the final silver recovery rate was 65.2%, and the gallium recovery rate was 59.8%.

[0050] Comparative Example 2 The process of removing iron using a non-weak magnetic separation method involves the following steps: (1) Ore pretreatment: Same as in Example 1.

[0051] (2) Strong magnetic pre-enrichment: Same as in Example 1, to obtain black tungsten crude concentrate (WO3 grade 28.5%, recovery rate 89.2%).

[0052] (3) Direct flotation for tungsten extraction: The wolfram concentrate is directly subjected to flotation without weak magnetic separation to remove iron. The reagent dosage and flotation process are the same as in Example 1, and tungsten concentrate (WO3 grade 65.7%, recovery rate 86.3%) is obtained.

[0053] (4) Silver-sulfur flotation and gallium extraction: The subsequent process is the same as in Example 1, with a final silver recovery rate of 85.1% and a gallium recovery rate of 82.3%.

[0054] Comparative Example 3 The gallium extraction process using direct acid leaching without calcination involves the following steps: (1) Ore pretreatment to silver-sulfur flotation: Same as in Example 1, to obtain silver-sulfur flotation tailings.

[0055] (2) Direct acid leaching for gallium extraction: Silver-sulfur flotation tailings were not roasted, but directly added to a 22% hydrochloric acid solution (liquid-solid ratio 6:1), and leached with stirring at 85°C for 2.5 h. 0.8% sodium chloride was then added. Subsequent purification, extraction, back-extraction, crystallization, and reduction roasting processes were the same as in Example 1, ultimately yielding metallic gallium (purity 99.90%, recovery rate 61.5%). Other indicators: tungsten concentrate (WO3 grade 72.1%, recovery rate 93.2%), silver recovery rate 86.5%.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A process for the recovery of tungsten, silver, gallium from wolframite containing ores, characterized in that, The method comprises the following steps: S1, ore pretreatment The black tungsten-containing ore is coarsely crushed, then medium crushed and ball milled, the particle size of the milled ore is controlled to be 80%-90% of -200 mesh, then water is added to adjust the concentration of the ore slurry to 30%-35%, and a pretreated ore slurry is obtained; S2, strong magnetic pre-concentration The pretreated ore slurry obtained in S1 is subjected to high-intensity magnetic separation for enriching wolframite at normal temperature, the magnetic field strength is controlled to be 18000-22000Gs, the ore slurry flow rate is 1.5-2.0m / h, and the flushing water pressure is 0.2-0.4MPa, to obtain wolframite rough concentrate and high-intensity magnetic tailings. 3 ​ S3, weak magnetic separation and iron removal The black tungsten rough concentrate obtained in S2 is subjected to weak magnetic separation at room temperature, the magnetic field strength is controlled to be 3000-5000Gs, the slurry concentration is adjusted to be 25%-30%, and the magnetic separation time is 8-12 min, and a low-iron black tungsten rough concentrate and an iron concentrate are obtained; S4, tungsten flotation The low-iron black tungsten rough concentrate obtained in S3 is taken, the slurry pH value is adjusted to be 8-9, a collector benzohydroxamic acid, a depressor sodium silicate and an activator aluminum sulfate are added, stirring is carried out at room temperature for 3-5 min, and then flotation is carried out, the flotation adopts a "one roughing, two cleaning and one scavenging" process, the roughing time is 8-10 min, the cleaning time is 5-6 min, and the scavenging time is 6-8 min, sodium silicate is additionally added during cleaning at 300-500 g / t, and finally a tungsten concentrate and a tungsten flotation tailing are obtained; S5, silver-sulfur flotation The strong magnetic tailing obtained in S2 is taken, the slurry concentration is adjusted to be 28%-32%, the slurry pH value is adjusted to be 9-10, a collector butyl xanthate, a frother 2# oil and a depressor lime are added, silver-sulfur flotation is carried out after stirring at room temperature for 2-3 min, and the flotation process is "one roughing and one cleaning": the roughing time is 6-8 min, and the cleaning time is 4-5 min, and a silver-sulfur rough concentrate and a silver-sulfur flotation tailing are obtained; S6, roasting-acid leaching for gallium extraction The silver-sulfur flotation tailing obtained in S5 is roasted at 750-850℃ for 3-4 h, oxygen is introduced during the roasting process, a roasted product is obtained, the roasted product is added into a hydrochloric acid solution with a concentration of 20%-25%, the liquid-solid ratio is 6:1, stirring leaching is carried out at 80-90℃ for 2-3 h, 0.5%-1.0% of sodium chloride is added during the leaching process, a gallium-containing leaching solution is obtained, aluminum hydroxide is added into the gallium-containing leaching solution to adjust the pH value to 3-4, precipitation is carried out for 1-1.5 h, filtration is carried out to obtain a purified gallium-containing solution, the purified gallium-containing solution is extracted by using N235 extractant with a volume fraction of 10%-15%, the extraction phase ratio is 1:3-1:5, the oscillation time is 15-20 min, a loaded organic phase is obtained, the loaded organic phase is back-extracted by using a hydrochloric acid solution with a concentration of 1.5-2.0 mol / L, the back-extraction phase ratio is 2:1-3:1, a back-extraction solution is obtained, the back-extraction solution is concentrated by evaporation, crystallization is carried out to obtain gallium chloride crystals, the gallium chloride crystals are reduced and roasted at 550-650℃ under a hydrogen atmosphere for 2-3 h, and metallic gallium is obtained.

2. The method of claim 1, wherein, The particle size after coarse crushing in S1 is ≤50 mm, and the particle size after medium crushing is ≤10 mm.

3. The method of claim 1, wherein, The slurry pH value in S4 is adjusted by using sodium carbonate, the amount of the collector benzohydroxamic acid is 100-150 g / t, the amount of the depressor sodium silicate is 800-1200 g / t, and the amount of the activator aluminum sulfate is 200-300 g / t.

4. The method of claim 1, wherein, The WO3 grade of the tungsten concentrate obtained in S4 is ≥70%, and the recovery rate is ≥92%.

5. The method of claim 1, wherein, The sodium hydroxide is used to adjust the pH value of the ore pulp in S5; the dosage of the butyl xanthate collector is 80-120 g / t, the dosage of the 2# oil frother is 20-30 g / t, and the dosage of the lime inhibitor is 500-800 g / t.

6. The method of claim 1, wherein, The silver grade of the silver-sulfur rough concentrate obtained in S5 is ≥1500 g / t, and the recovery rate is ≥85%.

7. The method of claim 1, wherein, The flow rate of oxygen introduced in the roasting process described in S6 is 5-8 m 3 / h.

8. The method of claim 1, wherein, The temperature of the evaporation and concentration of the stripping solution in S6 is 80-90 °C, the crystallization time is 4-6 h, and the flow rate of the hydrogen gas is 6-8 m 3 / h.

9. The method of claim 1, wherein, The purity of the metallic gallium obtained in S6 is ≥99.9%, and the recovery rate is ≥82%.