Method for mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten-molybdenum ore

Abstract

The invention discloses a method for mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten-molybdenum ore, which relates to the technical field of hydrometallurgy and comprises the following steps: (1) crushing, beneficiating and finely grinding the semi-oxidized tungsten-molybdenum ore to increase the specific surface area of the semi-oxidized tungsten-molybdenum ore; (2) lime and distilled water are added to adjust the concentration of ore pulp, the fine tungsten-molybdenum ore powder is pretreated, and meanwhile heating and preheating are conducted; and (3) vacuumizing the reaction kettle, introducing oxygen, and adjusting the oxygen pressure and the reaction temperature for leaching. According to the method, microcracks can be generated in the ore through mechanical activation, oxygen pressure leaching is accelerated, meanwhile, under the alkaline conditions of heating and pressurizing, tungsten-molybdenum-calcium ore and scheelite in the ore powder are transferred into a leaching solution, and the tungsten-molybdenum leaching rate is increased. Experimental results show that the tungsten and molybdenum leaching rate of the refractory semi-oxidized tungsten and molybdenum ore can be effectively improved by optimizing the grinding granularity, the oxygen pressure, the reaction temperature, the ore pulp concentration and the reagent adding amount at the same time, and efficient leaching of tungsten and molybdenum in the semi-oxidized tungsten and molybdenum ore is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for mechanical activation of semi-oxidized tungsten-molybdenum ores in coordination with oxygen pressure alkali leaching. Background Art

[0002] For semi-oxidized low-grade and difficult-to-process tungsten-molybdenum ores, the technology of first selection and then smelting is currently mainly used. A beneficiation method for low-grade tungsten-molybdenum ore (CN112517224A) discloses a process flow of first selecting molybdenum and then selecting tungsten. For molybdenum, a scheme of molybdenum-sulfur mixed selection and then separation is adopted, wherein the molybdenum-sulfur separation flotation is carried out after one roughing and seven concentrating to obtain molybdenum concentrate; for tungsten rough concentrate, two concentratings are carried out to obtain intermediate concentrate, and then one roughing and five concentratings are carried out to obtain tungsten concentrate, thus achieving effective separation and enrichment of tungsten and molybdenum. However, there are also problems of long process and complicated process.

[0003] There are also wet methods for smelting in the smelting process. A method for sodium hypochlorite oxidation and phosphate alkaline leaching of low-grade tungsten-molybdenum ore (CN118028629A) discloses a method for sodium hypochlorite oxidation and phosphate alkaline leaching in response to the difficulty of leaching molybdenite in a certain mine. The molybdenite is first oxidized and then leached with phosphate, which changes the existence form of molybdenite and tungsten-molybdenum calcium ore in the tungsten-molybdenum ore and improves the leaching rate. However, sodium hypochlorite is easily decomposed by heat, and the coordinated oxidation leaching easily causes a large amount of sodium hypochlorite waste and consumption, increasing costs.

[0004] Therefore, it is more critical to adopt efficient, economical and clean hydrometallurgical technology to extract tungsten and molybdenum from semi-oxidized tungsten and molybdenum ores. Summary of the invention

[0005] The purpose of the present invention is to provide a method for mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten-molybdenum ore. First, the ore after beneficiation is ground into smaller particles by an Isa mill to increase the specific surface area of ​​the ore. At the same time, microcracks are generated during the mechanical activation process to accelerate oxygen pressure leaching. Then, using the fact that tungsten-molybdenum calcium ore and scheelite have strong alkali reaction activity at a certain temperature and pressure, oxygen is introduced and lime is added, the slurry concentration is adjusted, and the temperature and pressure are increased to perform alkaline leaching to form tungstate ions and molybdate ions with higher solubility, thereby achieving oxidation leaching of tungsten-molybdenum calcium ore and scheelite.

[0006] The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores of the present invention comprises the following steps: (1) After the semi-oxidized tungsten-molybdenum ore is processed by ore dressing, it is ground to a particle size of -325 mesh (-44μm) accounting for more than 70%, and the prepared fine-grained tungsten-molybdenum ore powder is used as the raw material for leaching; (2) Place fine tungsten-molybdenum ore powder in a reactor, add lime, adjust the slurry concentration, evacuate the reactor and introduce oxygen, adjust the oxygen pressure, control the stirring rate to 400-600 rpm, and heat up for leaching for 0.5-1 h; (3) After the reaction is completed, the pressure is released and the filtration is performed, and the filter residue is washed with distilled water, and the filter residue is vacuum dried to obtain leaching residue and leaching liquid; (4) Analyze the contents of molybdenum and tungsten in fine-grained tungsten-molybdenum ore powder, leaching solution and leaching slag. The molybdenum and tungsten in fine-grained tungsten-molybdenum ore powder and leaching slag are measured as Mo and WO3 contents, respectively. The molybdenum and tungsten in the leaching solution are measured as Mo and W contents, respectively. The leaching rate is calculated based on the contents of molybdenum and tungsten in the leaching solution.

[0007] In the step (1), the semi-oxidized tungsten-molybdenum ore is a high-calcium, high-magnesium, high-fluorite, low-tungsten-molybdenum oxidized tungsten-molybdenum ore. After XRD phase analysis, the main components of the semi-oxidized tungsten-molybdenum ore are carbonate minerals including quartz, calcite, dolomite, feldspar, magnetite, garnet, diopside and fluorite. Some tungsten-molybdenum isomorphs in the semi-oxidized tungsten-molybdenum ore produce new minerals (tungsten-molybdenum-calcium ore), and the main valuable minerals are tungsten-molybdenum minerals, mainly tungsten-molybdenum-calcium ore and scheelite. The grade of WO3 is 0.27~0.78%, and the grade of Mo is 0.28~0.75%.

[0008] In the step (1), 50-90% of the tungsten-molybdenum-calcium ore in the fine-grained tungsten-molybdenum ore powder is distributed between 10 and 75 μm, and the mineral embedding particle size is relatively fine.

[0009] In the step (1), an ALC-100L Isa mill is used for grinding, the rotation speed is 800-900 rpm, and the sample preparation time is 2-15 min.

[0010] In the step (2), the reaction temperature is 80-100° C., and the amount of lime used is 4-16 kg / t of semi-oxidized tungsten-molybdenum ore.

[0011] In the step (2), the slurry concentration is 30-40%, and the pH value is controlled at 9-12.

[0012] In the step (2), the oxygen pressure is controlled at 0.1-0.6 MPa.

[0013] In the step (3), the solid-liquid separation is performed by vacuum filtration using a vacuum filter.

[0014] In the step (3), the amount of distilled water used to wash the filter residue is 500-1000 ml.

[0015] In the step (3), the leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 50-60° C. until constant weight is achieved.

[0016] In the step (4), ICP-OES is used to analyze the contents of molybdenum and tungsten in the fine-grained tungsten-molybdenum ore powder, the leaching solution and the leaching residue.

[0017] Compared with the prior art, the method of mechanical activation and oxygen pressure alkali leaching of semi-oxidized tungsten and molybdenum ores of the present invention has the following beneficial effects: The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten-molybdenum ore of the present invention first grinds the minerals after ore dressing into smaller particles through an Isa mill to increase the specific surface area of ​​the ore, and at the same time generates microcracks during the mechanical activation process to accelerate oxygen pressure leaching, and then realizes the oxidation leaching of tungsten-molybdenum calcium ore and scheelite through oxygen pressure alkaline leaching to form tungstate ions and molybdate ions with high solubility, thereby realizing the leaching of semi-oxidized tungsten-molybdenum ore, simplifying the process flow, and reducing the pollution and cost caused by the addition of oxidants. It has the characteristics of simple operation process, low production cost and environmental friendliness. The experimental results show that the simultaneous optimization of grinding particle size, oxygen pressure, reaction temperature, slurry concentration and reagent addition amount can effectively improve the tungsten and molybdenum leaching rate of the difficult-to-smelt semi-oxidized tungsten-molybdenum ore, and realize the efficient leaching of tungsten and molybdenum in the semi-oxidized tungsten-molybdenum ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a method for mechanical activation of semi-oxidized tungsten and molybdenum ores in coordination with oxygen pressure alkaline leaching in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The semi-oxidized tungsten-molybdenum ore after the ore dressing treatment in the embodiment of the present invention is ground by an Isa mill. The particle size of the fine tungsten-molybdenum ore powder is -325 mesh (-44 μm), accounting for more than 70%.

[0020] The tungsten ores in the fine-grained tungsten-molybdenum ore powder are tungsten-molybdenum-calcium ore and scheelite, and the molybdenum ores are tungsten-molybdenum-calcium ore. The grade of WO3 is 0.27~0.78%, and the grade of Mo is 0.28~0.75%.

[0021] In the embodiments of the present invention, the leaching is performed by increasing temperature and pressure, and the stirring is performed by mechanical stirring.

[0022] In the embodiment of the present invention, the fine-grained tungsten-molybdenum ore powder and lime are added as solids, and the slurry concentration is adjusted by distilled water. The materials are added at room temperature.

[0023] After the reaction is completed, the pressure is released and the filtrate is filtered, and the filter residue is washed with distilled water and vacuum dried to obtain leaching residue and leaching liquid.

[0024] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 50-60°C until constant weight is achieved.

[0025] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue, and the leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution.

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0027] Example 1 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.27% and Mo grade of 0.28% through ore dressing. The semi-oxidized tungsten-molybdenum ore is ground into fine-grained tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 800rpm using an Isa mill for 5 minutes until the particle size is -325 mesh (-44μm) accounting for more than 70%.

[0028] Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 4.0g of lime solid into a reactor, add 2L of distilled water, the slurry concentration is 33%, the pH value is 9-10, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.2MPa, raise the temperature to 80℃, adjust the stirring rate to 400rpm, and react for 0.5h.

[0029] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0030] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 50°C until constant weight is reached.

[0031] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 76.74% and the leaching rate of W was 73.13%.

[0032] Example 2 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.30% and Mo grade of 0.31% through ore dressing. The semi-oxidized tungsten-molybdenum ore is ground into fine-grained tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 800rpm using an Isa mill for 5 minutes until the particle size is -325 mesh (-44μm) accounting for more than 70%.

[0033] Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 4.0g of lime solid into a reactor, add 2L of distilled water, the slurry concentration is 33%, the pH value is 9-10, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.2MPa, heat to 80℃, adjust the stirring rate to 400rpm, and react for 0.5h.

[0034] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0035] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 50°C until constant weight is reached.

[0036] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 80.63% and the leaching rate of W was 76.45%.

[0037] Example 3 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.38% and Mo grade of 0.35% through ore dressing. The semi-oxidized tungsten-molybdenum ore is ground into fine-grained tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 800rpm using an Isa mill for 5 minutes until the particle size is -325 mesh (-44μm) accounting for more than 70%.

[0038] Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 8.0g of lime solid into a reactor, add 2L of distilled water, the slurry concentration is 33%, the pH value is 10-11, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.2MPa, heat to 80℃, adjust the stirring rate to 400rpm, and react for 0.5h.

[0039] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0040] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 50°C until constant weight is reached.

[0041] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 86.33% and the leaching rate of W was 78.25%.

[0042] Example 4 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.48% and Mo grade of 0.41% through ore dressing. The semi-oxidized tungsten-molybdenum ore is ground into fine-grained tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 800rpm with an Isa mill for 5 minutes until the particle size is -325 mesh (-44μm) accounting for more than 70%.

[0043] Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 8.0g of lime solid into a reactor, add 2L of distilled water, the slurry concentration is 33%, the pH value is 10-11, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.2MPa, raise the temperature to 90℃, adjust the stirring rate to 500rpm, and react for 0.5h.

[0044] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0045] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 50°C until constant weight is reached.

[0046] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 86.89% and the leaching rate of W was 85.16%.

[0047] Example 5 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.51% and Mo grade of 0.50% through ore dressing and batching; the semi-oxidized tungsten-molybdenum ore is ground into fine tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 800rpm with an Isa mill for 5 minutes until the particle size is -325 mesh (-44μm) accounting for more than 70%; Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 12.0g of lime solid into a reactor, add 2L of distilled water, the slurry concentration is 33%, the pH value is 10-11, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.4MPa, heat to 90℃, adjust the stirring rate to 500rpm, and react for 0.5h.

[0048] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0049] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 60°C until constant weight is achieved.

[0050] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 88.39% and the leaching rate of W was 86.07%.

[0051] Example 6 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.57% and Mo grade of 0.56% through ore dressing and batching; the semi-oxidized tungsten-molybdenum ore is ground into fine tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 900rpm by Isa mill for 10 minutes until the particle size is -325 mesh (-44μm) accounting for more than 80%; Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 12.0g of lime solid into a reactor, add 1.5L of distilled water, the slurry concentration is 40%, the pH value is 11-12, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.4MPa, raise the temperature to 90℃, adjust the stirring rate to 500rpm, and react for 1h.

[0052] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0053] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 60°C until constant weight is achieved.

[0054] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 92.73% and the leaching rate of W was 90.11%.

[0055] Example 7 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.67% and Mo grade of 0.64% through ore dressing. The semi-oxidized tungsten-molybdenum ore is ground into fine-grained tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 900rpm with an Isa mill for 10 minutes until the particle size is -325 mesh (-44μm) accounting for more than 80%.

[0056] Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 16.0g of lime solid into a reactor, add 1.5L of distilled water, the slurry concentration is 40%, the pH value is 11-12, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.4MPa, raise the temperature to 90℃, adjust the stirring rate to 600rpm, and react for 1h.

[0057] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0058] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 60°C until constant weight is achieved.

[0059] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 93.69% and the leaching rate of W was 91.76%.

[0060] Example 8 Process such as Figure 1 As shown in the figure, the semi-oxidized tungsten-molybdenum ore is prepared with WO3 grade of 0.78% and Mo grade of 0.75% through ore dressing and batching; the semi-oxidized tungsten-molybdenum ore is ground into fine tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 900rpm by Isa mill for 10 minutes until the particle size is -325 mesh (-44μm) accounting for more than 80%; Weigh 1kg of fine-grained tungsten-molybdenum ore powder and 16.0g of lime solid into a reactor, add 1.5L of distilled water, the slurry concentration is 40%, the pH value is 11-12, evacuate the reactor and connect the oxygen valve to control the oxygen pressure to 0.6MPa, heat to 100℃, adjust the stirring rate to 600rpm, and react for 1h.

[0061] After stopping the reaction, the pressure was released and the filter was immediately filtered, and the filter residue was washed four times with 500 ml of distilled water.

[0062] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 60°C until constant weight is achieved.

[0063] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 95.29% and the leaching rate of W was 92.26%.

[0064] Table 1 Process parameters and leaching rates of molybdenum and tungsten in Examples 1-8 Example Ore particle size - 325 mesh proportion (%) Slurry concentration (%) Lime(kg / t) Oxygen pressure (MPa) Time (h) Temperature(℃) Stirring speed (rpm) Mo leaching rate (%) W leaching rate (%) 1 70 33 4 0.2 0.5 80 400 76.74 73.13 2 70 33 4 0.2 0.5 80 400 80.63 76.45 3 70 33 8 0.2 0.5 80 400 86.33 78.25 4 70 33 8 0.2 0.5 90 500 86.89 85.16 5 70 33 12 0.4 0.5 90 500 88.39 86.07 6 80 40 12 0.4 1 90 500 92.73 90.11 7 80 40 16 0.4 1 90 600 93.69 91.76 8 80 40 16 0.6 1 100 600 95.29 92.26

[0065] Comparative Example 1 The semi-oxidized tungsten-molybdenum ore is prepared by beneficiation and proportioning to a WO3 grade of 0.48% and a Mo grade of 0.35%. The semi-oxidized tungsten-molybdenum ore is ground into fine tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 3000rpm with an Isa mill for 5 minutes until the particle size is -625 mesh (-20μm) accounting for about 70%. Weigh 1.0 kg of fine tungsten-molybdenum ore powder, 10 g of NaClO solid and 20 g of NaOH solid into a reactor, add 3 L of distilled water, the slurry concentration is 25%, the pH value is about 13, heat to 80 ° C, adjust the stirring rate to 500 rpm, and react for 2 hours.

[0066] After stopping the reaction, filter immediately and wash the filter residue four times with 500 ml of distilled water.

[0067] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 60°C until constant weight is achieved.

[0068] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 64.63% and the leaching rate of W was 50.61%.

[0069] Comparative Example 2 The semi-oxidized tungsten-molybdenum ore is prepared by beneficiation and proportioning to a WO3 grade of 0.48% and a Mo grade of 0.35%. The semi-oxidized tungsten-molybdenum ore is ground into fine tungsten-molybdenum ore powder by adjusting the speed of the semi-oxidized tungsten-molybdenum ore to 3000rpm with an Isa mill for 5 minutes until the particle size is -625 mesh (-20μm) accounting for about 70%. Weigh 50.0g of fine-grained tungsten-molybdenum ore powder, 4.8g of NaOH solid, 7.6g of trisodium phosphate solid and 0.6g of NaClO solid into a conical flask, add 150mL of distilled water, the slurry concentration is 25%, the pH value is about 13, heat to 80℃, adjust the stirring rate to 500rpm, and react for 4h.

[0070] After stopping the reaction, filter immediately and wash the filter residue four times with 500 ml of distilled water.

[0071] The leached residue after filtering and washing is dried in a vacuum drying oven at a drying temperature of 60°C until constant weight is achieved.

[0072] ICP-OES was used to analyze the contents of molybdenum and tungsten in the leaching solution and the leaching residue. The leaching rates of molybdenum and tungsten were calculated based on the contents of molybdenum and tungsten in the leaching solution. At this time, the leaching rate of Mo was 62.49% and the leaching rate of W was 55.26%.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, which should also be regarded as the protection scope of the present invention.

Claims

1. A method for mechanical activation of semi-oxidized tungsten and molybdenum ores in coordination with oxygen pressure alkaline leaching, characterized in that: The following steps are involved: (1) After the semi-oxidized tungsten-molybdenum ore is beneficiated, it is ground by an Isa mill to a particle size of more than 70% of -325 mesh, with a rotation speed of 800-900 rpm and a sample preparation time of 2-15 min to obtain fine tungsten-molybdenum ore powder as the raw material for leaching; (2) Place fine tungsten-molybdenum ore powder in a reactor, add lime, adjust the slurry concentration to 30-40%, evacuate the reactor and introduce oxygen, control the oxygen pressure at 0.1-0.6 MPa, heat and start stirring, the stirring rate is 400-600 rpm, the reaction time is 0.5-1 h, and the reaction temperature is 80-100 °C; (3) After the reaction is completed, the pressure is released and filtered, and the filter residue is washed with distilled water, and the filter residue is vacuum dried to obtain leaching residue and leaching liquid; (4) Analyze the contents of molybdenum and tungsten in fine-grained tungsten-molybdenum ore powder, leaching solution and leaching slag. The molybdenum and tungsten in fine-grained tungsten-molybdenum ore powder and leaching slag are measured as Mo and WO3 contents, respectively. The molybdenum and tungsten in the leaching solution are measured as Mo and W contents, respectively. The leaching rate is calculated based on the contents of molybdenum and tungsten in the leaching solution.

2. The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores according to claim 1 is characterized in that: The semi-oxidized tungsten-molybdenum ore is a high-calcium, high-magnesium, high-fluorite, low-tungsten-molybdenum oxidized tungsten-molybdenum ore. After XRD phase analysis, the main components of the semi-oxidized tungsten-molybdenum ore are carbonate minerals including quartz, calcite, dolomite, feldspar, magnetite, garnet, diopside and fluorite. Some tungsten-molybdenum isomorphs in the semi-oxidized tungsten-molybdenum ore produce tungsten-molybdenum-calcium ore. The main valuable minerals are tungsten-molybdenum minerals, mainly tungsten-molybdenum-calcium ore and scheelite.

3. The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores according to claim 1 is characterized in that: In the step (1), the tungsten-containing minerals in the semi-oxidized tungsten-molybdenum ore are tungsten-molybdenite and scheelite, and the molybdenum-containing mineral is tungsten-molybdenum-calcium ore, wherein the WO3 grade is 0.27-0.78% and the Mo grade is 0.28-0.75%.

4. The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores according to claim 1 is characterized in that: In the step (1), 50-90% of the tungsten-molybdenum-calcium ore in the fine-grained tungsten-molybdenum ore powder is distributed between 10-75 μm, and the mineral embedding particle size is fine.

5. The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores according to claim 1 is characterized in that: The amount of lime used in step (2) is 4-16 kg / t of semi-oxidized tungsten-molybdenum ore.

6. The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores according to claim 1 is characterized in that: In the step (2), the pH value is controlled at 9-12.

7. The method of mechanical activation and oxygen pressure alkaline leaching of semi-oxidized tungsten and molybdenum ores according to claim 1 is characterized in that: The filtration in step (3) is specifically carried out by using a vacuum filter; the amount of distilled water used to wash the filter residue is 500-1000 ml; the vacuum drying is carried out by using a vacuum drying oven at a drying temperature of 50-60° C. and drying to constant weight.

Images