Method for efficient recycling of molybdenum removal slag in tungsten smelting

Abstract

The application discloses a method for efficiently recycling molybdenum-removed residue in tungsten smelting, the molybdenum-removed residue containing tungsten, molybdenum and copper, comprising the following steps: using ammonia and manganese dioxide to perform first high-temperature leaching treatment on the molybdenum-removed residue to obtain a tungsten-copper-containing residue and an ammonium molybdate solution; and using ammonia and manganese dioxide to perform second high-temperature leaching treatment on the molybdenum-removed residue to obtain a copper ammonia solution; and using the obtained copper ammonia solution as a molybdenum removal reagent to perform molybdenum removal treatment on a molybdenum-containing ammonium tungstate solution. According to the method for efficiently recycling molybdenum-removed residue in tungsten smelting, effective separation of tungsten and molybdenum can be realized, the recycling efficiency of tungsten and molybdenum is high, copper can be recycled, the cost of the molybdenum removal reagent is reduced, the risk of environmental pollution is reduced, and the purpose of efficiently recycling the molybdenum-removed residue is achieved.

Description

Technical Field

[0001] This invention relates to the field of metallurgy and mining, and in particular to a method for the efficient recovery and utilization of molybdenum slag from tungsten smelting. Background Technology

[0002] Tungsten and molybdenum are both commonly used rare metals, widely applied in aerospace, energy materials, and catalysts. In tungsten smelting, due to the extreme similarity in atomic radius, chemical valence state, and chemical properties, tungsten and molybdenum often occur together. Since the tungsten smelting product APT has a very high molybdenum content requirement (≤20ppm), tungsten-molybdenum separation is a crucial step in the smelting process. Currently, most tungsten smelting enterprises in my country use selective precipitation, ion exchange separation, and solvent extraction methods for tungsten-molybdenum separation. The solid residue after molybdenum removal in tungsten smelting is called molybdenum-removed slag. This residue still contains various valuable elements such as copper, nickel, chromium, tungsten, and molybdenum, as well as harmful substances. Furthermore, this waste residue is often piled up or discarded, becoming solid waste in smelting plants, easily causing environmental pollution problems related to sediment slag systems. Molybdenum-removed slag is also explicitly listed as hazardous waste in the "National Hazardous Waste List." Therefore, the treatment of molybdenum-removed slag must not only consider the resource recovery and utilization of various valuable elements but also take into account the environmental impact of the recovery process.

[0003] The treatment of molybdenum slag has always been a challenging problem for metallurgists and chemical engineers. Currently, the common method involves reacting the slag with sodium hydroxide or hydrogen peroxide to leach out tungsten and molybdenum. Under alkaline conditions, tungsten, molybdenum, and some sulfur in the slag can decompose and enter the solution. Tungsten exists in the solution as tungstate, molybdenum as molybdate, and copper as CuS. This method has drawbacks: it requires a large amount of alkaline solution, has low tungsten and molybdenum recovery rates, and tungsten is also present in the system during copper recovery, leading to some tungsten loss. Furthermore, hydrogen peroxide is unstable under alkaline heating conditions, and other sodium salt oxidants introduce sodium ions during oxidation, which are impurities and affect the quality of the final APT product. Additionally, the resulting sodium molybdate mixture requires secondary conversion before further processing into molybdenum products. Another method is to add ammonium sulfide to sulfide the molybdenum, followed by the addition of copper sulfide or copper sulfate to precipitate the molybdenum as a sparingly soluble compound. This method has drawbacks: the molybdenum removal reagents, such as ammonium sulfide, copper sulfide, or copper sulfate, are relatively expensive, resulting in high molybdenum removal costs. Another method involves roasting the molybdenum-removing slag to remove sulfur, followed by alkaline leaching to separate copper and leach out tungsten and molybdenum. This method has drawbacks: the toxic SO2 gas generated during roasting severely pollutes the environment, and the production environment is extremely harsh.

[0004] Patent application CN103602807B discloses a method for treating molybdenum-removing slag generated during tungsten smelting. The method involves first leaching tungsten with dilute ammonia, then leaching molybdenum with concentrated ammonia and copper sulfate solution. The resulting copper sulfide slag is used for molybdenum removal, achieving comprehensive recovery of valuable elements tungsten, molybdenum, and copper. However, this method has drawbacks: copper sulfate, the molybdenum removal reagent, is relatively expensive, resulting in high molybdenum removal costs. Furthermore, the separation of tungsten and molybdenum is incomplete, hindering efficient leaching and recovery of tungsten and molybdenum, and causing some tungsten loss. Additionally, the resulting copper sulfide slag needs to be dried, crushed, and ground to a certain particle size before it can be reused for molybdenum removal, making the process complex.

[0005] Patent application CN110629053B discloses a method for the comprehensive recovery of copper, molybdenum, tungsten, and sulfur from molybdenum slag in tungsten smelting. The method involves heating the product in a tubular electric furnace, introducing chlorine gas to obtain a gaseous product, and then sequentially passing it through three constant-temperature storage tanks at different temperatures to allow it to cool naturally to room temperature. Elemental sulfur, tungsten chloride, and molybdenum chloride are collected separately, achieving the separation of copper, molybdenum, tungsten, and sulfur, and the recycling of copper resources. However, this method has drawbacks: the process is complex, the equipment requirements are high, and the chlorine gas is pungent and highly toxic, posing a risk of leakage or rupture during transportation or use.

[0006] In summary, current methods for treating molybdenum slag have several drawbacks, including low molybdenum recovery rates, incomplete separation, high costs, complex processes, and environmental pollution. Furthermore, the recovered copper cannot be directly recycled back into the tungsten smelting process. Therefore, improving the treatment methods for molybdenum slag from tungsten smelting is crucial for tungsten smelting enterprises. Summary of the Invention

[0007] The purpose of this invention is to overcome the difficulties existing in the recycling and treatment of molybdenum slag from tungsten smelting, and to provide a method for the efficient recycling and utilization of molybdenum slag from tungsten smelting. This method can effectively separate tungsten and molybdenum, achieve high tungsten and molybdenum recovery efficiency, reuse copper as a resource, reduce the cost of molybdenum removal reagents, and reduce the risk of environmental pollution, thereby achieving the goal of efficient recycling and utilization of molybdenum slag.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A method for the efficient recovery and utilization of molybdenum-removed slag from tungsten smelting is disclosed. The method includes: performing a first high-temperature leaching treatment on the molybdenum-removed slag using ammonia and manganese dioxide to obtain tungsten-containing copper slag and ammonium molybdate solution; and performing a second high-temperature leaching treatment on the obtained tungsten-containing copper slag using ammonia and manganese dioxide to obtain copper ammonia solution. The reaction temperature of the first high-temperature leaching treatment is 85-100℃, the reaction temperature of the second high-temperature leaching treatment is 120-150℃, and the ammonia concentration used in the first high-temperature leaching treatment is lower than that used in the second high-temperature leaching treatment.

[0010] Furthermore, the molybdenum-removing slag contains tungsten, molybdenum, and copper.

[0011] Optionally, the copper ammonia solution is used to remove molybdenum from the molybdenum-containing ammonium tungstate solution.

[0012] Furthermore, the concentration of ammonia in the first high-temperature leaching treatment is 1.5-3 mol / L.

[0013] Optionally, the first high-temperature leaching time is 6-10 hours.

[0014] Furthermore, the ratio of the molar amount of ammonia water in the first high-temperature leaching treatment to the mass of the molybdenum-removed slag is (0.375 mol: 100 g) - (1.2 mol: 100 g).

[0015] Optionally, the ratio of the mass of manganese dioxide in the first high-temperature leaching treatment to the mass of the molybdenum-removed slag is (1g:50g)-(1g:100g).

[0016] Furthermore, the ammonia concentration in the second high-temperature leaching treatment is 4-6 mol / L.

[0017] Optionally, the second high-temperature leaching time is 6-12 hours.

[0018] Furthermore, the ratio of the molar amount of ammonia water in the second high-temperature leaching treatment to the mass of the tungsten-containing copper slag is (0.667 mol: 100 g) - (1.667 mol: 100 g).

[0019] Furthermore, the ratio of the mass of manganese dioxide in the second high-temperature leaching treatment to the mass of the tungsten-containing copper slag is (1g:45g)-(1g:90g).

[0020] Furthermore, the use of the copper ammonia solution to remove molybdenum from molybdenum-containing ammonium tungstate solution includes: taking the ammonium tungstate solution to be removed from industrial production, adding ammonium sulfide for sulfidation, wherein the amount of ammonium sulfide added is 1.5-2.5 times the amount of molybdenum, then adding 1.5-3 times the amount of molybdenum in copper ammonia solution, stirring at room temperature for 1-2 hours, separating the solid and liquid, and obtaining the solid as the molybdenum-removed slag.

[0021] Furthermore, the molybdenum concentration before and after molybdenum removal can be measured by sampling, and then the average molybdenum removal rate can be calculated.

[0022] Furthermore, the specific process conditions for using the copper ammonia solution to remove molybdenum from the molybdenum-containing ammonium tungstate solution are not particularly limited. According to a specific embodiment of the present invention, the reaction can be carried out under the conditions of ammonium sulfide sulfidation for 2-4 hours, stirring at room temperature of 15-30°C, and stirring speed of 200-400 r / min, thereby further improving the average molybdenum removal rate.

[0023] Compared with existing methods for treating molybdenum slag, the main advantages of this invention are:

[0024] (1) Effective Separation: Through extensive research and practical experiments, this invention has discovered the different solubility characteristics of tungsten and molybdenum under different concentrations of ammonia and reaction temperatures. Furthermore, by optimizing the two-stage high-temperature ammonia leaching process, especially through precise control of temperature, dosage, and reaction time, it ensures that ammonia gas is not volatilized while significantly promoting the dissolution of tungsten and molybdenum in the molybdenum-removed slag and improving reaction efficiency. The first high-temperature leaching treatment targets molybdenum leaching, and the second high-temperature leaching treatment targets tungsten leaching, achieving effective separation of tungsten and molybdenum. This invention effectively avoids the problem of difficult separation of tungsten and molybdenum in a single ammonia leaching process, and does not introduce additional impurity elements, ensuring the APT content standard requirements for molybdenum in tungsten smelting products and improving product purity.

[0025] (2) High efficiency recovery: The present invention adopts different recovery paths for tungsten, molybdenum and copper, which can not only ensure the recovery rate of the three valuable metals, but also avoid the interference of molybdenum on the recovery of tungsten, significantly improving the recovery efficiency of valuable metal resources, realizing the maximum recovery of tungsten, molybdenum and copper in tungsten smelting slag, and has strong economic and practical value.

[0026] (3) Reduced cost: The present invention uses only ammonia water and manganese dioxide as reagents. By controlling the temperature and reagent concentration and dosage, the complexity of the process and the cost of molybdenum removal reagents are greatly reduced. At the same time, the molybdenum removal process is a liquid-to-liquid reaction, which makes the molybdenum removal efficiency higher, the operation simpler and more convenient, easy to industrialize, and the cost of molybdenum slag treatment is very low, which improves production efficiency.

[0027] (4) Resource reuse: The copper ammonia solution recovered by this invention can also be used as a molybdenum removal reagent to remove molybdenum from molybdenum-containing ammonium tungstate solution, achieving complete recovery and reuse of copper elements, realizing the resource reuse of copper, avoiding resource waste, reducing the generation of waste residue, reducing the risk of environmental pollution, and further reducing production costs, with broad application prospects. Detailed Implementation

[0028] The preferred embodiments of the present invention are described in detail below and are intended to explain the present invention, but should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially. In the following embodiments, unless otherwise specified, "%" refers to weight percentage.

[0029] The following examples and comparative examples all use molybdenum-removed slag from tungsten smelting as raw material, and its main components are shown in Table 1 (tungsten and molybdenum are calculated as WO3 and Mo, respectively):

[0030] Table 1. Main components and content of molybdenum-removing slag (mass percentage)

[0031] content(%) 26.6 18 1.5 15.3

[0032] Example 1: This specific implementation method is a method for the efficient recovery and utilization of molybdenum slag from tungsten smelting, specifically described as follows:

[0033] First high-temperature leaching treatment: 300g of molybdenum-removed slag, 750mL of 1.5mol / L ammonia solution, and 3g of manganese dioxide were weighed and added to the reactor for the first high-temperature leaching treatment. The reaction temperature was 85℃, and the leaching time was 6 hours. After solid-liquid separation, tungsten-containing copper slag and ammonium molybdate solution were obtained. After the first high-temperature leaching, the leaching rates of tungsten, molybdenum, and copper in the molybdenum-removed slag were 1.3%, 97.3%, and 0.2%, respectively.

[0034] Second high-temperature leaching treatment: The tungsten-containing copper slag was dried, and 270g of the slag, 450mL of 4mol / L ammonia solution, and 3g of manganese dioxide were added to the reactor for a second high-temperature leaching treatment. The reaction temperature was 120℃, and the leaching time was 6h. After solid-liquid separation, a copper-ammonia solution was obtained. After the second high-temperature leaching, the leaching rates of tungsten and copper in the tungsten-containing copper slag were 97.2% and 96.9%, respectively, and the copper concentration in the copper-ammonia solution was 79.8g / L.

[0035] Example 2: This specific implementation method is a method for the efficient recovery and utilization of molybdenum slag from tungsten smelting, specifically described as follows:

[0036] First high-temperature leaching treatment: 300g of molybdenum-removed slag, 1200mL of 3mol / L ammonia solution, and 6g of manganese dioxide were weighed and added to a reaction vessel for the first high-temperature leaching treatment. The reaction temperature was 100℃, and the leaching time was 10h. After solid-liquid separation, tungsten-containing copper slag and ammonium molybdate solution were obtained. After the first high-temperature leaching, the leaching rates of tungsten, molybdenum, and copper in the molybdenum-removed slag were 3%, 98.8%, and 0.6%, respectively.

[0037] Second high-temperature leaching treatment: The tungsten-containing copper slag was dried, and 270g of the slag, 750mL of 6mol / L ammonia solution, and 6g of manganese dioxide were added to the reactor for a second high-temperature leaching treatment. The reaction temperature was 150℃, and the leaching time was 10h. After solid-liquid separation, a copper-ammonia solution was obtained. After the second high-temperature leaching, the leaching rates of tungsten and copper in the tungsten-containing copper slag were 99.1% and 99.3%, respectively, and the copper concentration in the copper-ammonia solution was 51.1g / L.

[0038] Example 3: This specific embodiment is a method for the efficient recovery and utilization of molybdenum slag from tungsten smelting, specifically described as follows:

[0039] First high-temperature leaching treatment: 300g of molybdenum-removed slag, 900mL of 2mol / L ammonia solution, and 5g of manganese dioxide were weighed and added to a reaction vessel for the first high-temperature leaching treatment. The reaction temperature was 90℃, and the leaching time was 8h. After solid-liquid separation, tungsten-containing copper slag and ammonium molybdate solution were obtained. After the first high-temperature leaching, the leaching rates of tungsten, molybdenum, and copper in the molybdenum-removed slag were 2.3%, 97.1%, and 0.4%, respectively.

[0040] Second high-temperature leaching treatment: The tungsten-containing copper slag was dried, and 270g of the slag, 600mL of 5mol / L ammonia solution, and 5g of manganese dioxide were added to the reactor for a second high-temperature leaching treatment. The reaction temperature was 130℃, and the leaching time was 8h. After solid-liquid separation, a copper-ammonia solution was obtained. After the second high-temperature leaching, the leaching rates of tungsten and copper in the tungsten-containing copper slag were 97.1% and 98.2%, respectively, and the copper concentration in the copper-ammonia solution was 58.9g / L.

[0041] Example 4: This specific embodiment is a method for the efficient recovery and utilization of molybdenum slag from tungsten smelting, specifically described as follows:

[0042] First high-temperature leaching treatment: 300g of molybdenum-removed slag, 1050mL of 2.5mol / L ammonia solution, and 4g of manganese dioxide were weighed and added to a reaction vessel for the first high-temperature leaching treatment. The reaction temperature was 90℃, and the leaching time was 9h. After solid-liquid separation, tungsten-containing copper slag and ammonium molybdate solution were obtained. After the first high-temperature leaching, the leaching rates of tungsten, molybdenum, and copper in the molybdenum-removed slag were 1.9%, 97.1%, and 0.3%, respectively.

[0043] Second high-temperature leaching treatment: The tungsten-containing copper slag was dried, and 270g of the slag, 675mL of 4.5mol / L ammonia solution, and 4g of manganese dioxide were added to the reactor for a second high-temperature leaching treatment. The reaction temperature was 140℃, and the leaching time was 9h. After solid-liquid separation, a copper-ammonia solution was obtained. After the second high-temperature leaching, the leaching rates of tungsten and copper in the tungsten-containing copper slag were 97.7% and 98.6%, respectively, and the copper concentration in the copper-ammonia solution was 65.7g / L.

[0044] Example 5: This specific embodiment is a method for the efficient recovery and utilization of molybdenum slag from tungsten smelting, specifically described as follows:

[0045] First high-temperature leaching treatment: 300g of molybdenum-removed slag, 900mL of 2.5mol / L ammonia solution, and 6g of manganese dioxide were weighed and added to a reaction vessel for the first high-temperature leaching treatment. The reaction temperature was 95℃, and the leaching time was 10h. After solid-liquid separation, tungsten-containing copper slag and ammonium molybdate solution were obtained. After the first high-temperature leaching, the leaching rates of tungsten, molybdenum, and copper in the molybdenum-removed slag were 2.2%, 97.3%, and 0.5%, respectively.

[0046] Second high-temperature leaching treatment: The tungsten-containing copper slag was dried, and 270g of the slag, 450mL of 4.5mol / L ammonia solution, and 6g of manganese dioxide were added to the reactor for a second high-temperature leaching treatment. The reaction temperature was 120℃, and the leaching time was 12h. After solid-liquid separation, a copper-ammonia solution was obtained. After the second high-temperature leaching, the leaching rates of tungsten and copper in the tungsten-containing copper slag were 97.4% and 98.9%, respectively, and the copper concentration in the copper-ammonia solution was 81.1g / L.

[0047] Example 6:

[0048] The copper ammonia solution obtained in Examples 1-5 was used to remove molybdenum from molybdenum-containing ammonium tungstate solution. Specifically, the molybdenum concentration before removal was determined by the thiocyanate colorimetric method to be 0.8 g / L. After adding 1.5 times the amount of molybdenum in ammonium sulfide and sulfiding for 2 hours, 1.5 times the amount of molybdenum in copper ammonia solution was added. The mixture was stirred for 1 hour at 15°C and 200 r / min. Samples were taken and the molybdenum concentrations after removal were measured to be 0.020 g / L, 0.021 g / L, 0.023 g / L, 0.022 g / L, and 0.022 g / L, respectively. The average molybdenum removal rate was calculated as (∑molybdenum concentration before removal - ∑molybdenum concentration after removal) ÷ ​​∑molybdenum concentration before removal, resulting in an average molybdenum removal rate of 97.3%. The molybdenum content of the distilled APT was ≤12 ppm, meeting the national grade 0 product requirements.

[0049] Example 7:

[0050] The copper ammonia solution obtained in Examples 1-5 was used to remove molybdenum from a molybdenum-containing ammonium tungstate solution. Specifically, the molybdenum concentration before removal was determined by the thiocyanate colorimetric method to be 0.8 g / L. After adding 2.5 times the amount of molybdenum in ammonium sulfide and sulfiding for 4 hours, 3 times the amount of molybdenum in copper ammonia solution was added. The mixture was stirred at 30°C and 400 r / min for 2 hours. Samples were taken and the molybdenum concentrations after removal were measured to be 0.015 g / L, 0.017 g / L, 0.014 g / L, 0.013 g / L, and 0.015 g / L, respectively. The average molybdenum removal rate was calculated as (∑molybdenum concentration before removal - ∑molybdenum concentration after removal) ÷ ​​∑molybdenum concentration before removal, yielding an average removal rate of 98.5%. The molybdenum content of the distilled APT was ≤12 ppm, meeting the national grade 0 standard. Comparative Example 1:

[0051] Using a conventional molybdenum removal method, the molybdenum removal slag is dried, ground, and passed through a 300-mesh sieve. 100g of the sieve-passing material and 500mL of 10mol / L ammonia solution are added to a reaction vessel. The oxygen partial pressure inside the reaction vessel is controlled at 2.5MPa. After reacting at 70℃ for 10h, solid-liquid separation is performed. The leaching rates of tungsten, molybdenum, and copper in the molybdenum removal slag are 96.2%, 96.6%, and 95.6%, respectively. The leachate is passed through an ion exchange column packed with a strong base anion exchange resin to adsorb molybdenum and tungsten in the solution. The resulting copper-containing post-exchange solution is then evaporated and concentrated for use in the molybdenum removal process of tungsten smelting.

[0052] The results showed that, in Comparative Example 1, except for the molybdenum slag which required grinding before leaching, the leaching rates of tungsten, molybdenum, and copper were all lower than those in Examples 1-5 of this invention. Furthermore, after simultaneous leaching of tungsten, molybdenum, and copper, they still needed to be separated and recovered separately, making subsequent processes complex. Each additional process increased mechanical losses of materials, thus raising production costs. Meanwhile, the inventors found through relevant research and experiments that further improving the molybdenum leaching rate required selecting more precise grinding equipment, increasing the reaction temperature, and increasing the oxygen partial pressure, all of which placed more stringent demands on equipment, significantly increasing investment costs, and yielding no significant benefits. Comparative Example 2:

[0053] 100g of molybdenum-removed slag and 360mL of 1.5mol / L ammonia solution were weighed and subjected to a first leaching treatment at 80℃, yielding molybdenum-copper slag and ammonium tungstate leachate. The leaching rates of tungsten and molybdenum in the molybdenum-removed slag were 92.8% and 5.5%, respectively. A second leaching treatment was then performed on the molybdenum-copper slag at 120℃, using 360mL of 4mol / L ammonia solution and 100mL of 100g / L copper sulfate solution, yielding copper sulfide slag and ammonium molybdate. The leaching solution showed a molybdenum leaching rate of 93.7%. Copper sulfide slag was ground and sieved to obtain copper sulfide particles with a particle size of less than 8 μm. These particles were then mixed with a molybdenum-containing ammonium tungstate solution (molybdenum concentration of 0.7 g / L, with 5 times the amount of molybdenum added) that had been sulfided with ammonium sulfide for 4 hours. The mixture was stirred for 2 hours at a stirring speed of 400 r / min and aged for 6 hours. The molybdenum concentration after removal was measured to be 0.025 g / L, with an average molybdenum removal rate of 96.4%.

[0054] The results showed that copper sulfate, the reagent in Comparative Example 2, was relatively expensive, resulting in high costs for molybdenum removal. Furthermore, the incomplete separation of tungsten and molybdenum led to some tungsten loss. Additionally, the copper sulfide slag needed to be re-ground to a certain particle size before reuse, increasing recycling costs. Comparative Example 3:

[0055] Referring to Example 2, with other conditions unchanged, only the manganese dioxide in Example 2 was replaced with sodium hydroxide, and the resulting molybdenum solution was sodium molybdate. After the first high-temperature leaching, the leaching rates of tungsten and molybdenum in the molybdenum slag were 95.9% and 96.8%, respectively; after the second high-temperature leaching, the leaching rate of tungsten in the tungsten-containing copper slag was 1.6%, and copper could not be leached in either leaching, so copper remained in the slag phase.

[0056] The results showed that the introduction of sodium ions, which are impurity elements, in Comparative Example 3 affected the quality of the final APT product. In addition, the resulting sodium molybdate mixture required secondary conversion before it could be further processed into molybdenum products and could not be directly recycled.

[0057] Comparative Example 4:

[0058] Referring to Example 2, with other conditions unchanged, only the ammonia concentration in Example 2 was changed to 6 mol / L and 1200 mL for the first high-temperature leaching treatment, which was higher than the 3 mol / L and 450 mL for the second high-temperature leaching treatment. After the first high-temperature leaching, the leaching rates of tungsten, molybdenum, and copper in the molybdenum slag were 13%, 96.8%, and 13.1%, respectively. After the second high-temperature leaching, the leaching rates of tungsten and copper in the tungsten-containing copper slag were 3% and 48.1%, respectively, and the copper concentration in the copper-ammonia solution was 25.1 g / L. The results show that the separation of tungsten, molybdenum, and copper in Comparative Example 4 was incomplete, and efficient leaching and recovery were not possible.

[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for the efficient recovery and utilization of molybdenum removal slag from tungsten smelting, wherein the molybdenum removal slag contains tungsten, molybdenum, and copper, characterized in that, include: The molybdenum-removed slag undergoes a first high-temperature leaching treatment using ammonia and manganese dioxide to obtain tungsten-containing copper slag and an ammonium molybdate solution. The resulting tungsten-containing copper slag is then subjected to a second high-temperature leaching treatment using ammonia and manganese dioxide to obtain a copper-ammonia solution. The reaction temperature for the first high-temperature leaching treatment is 85-100℃, and the reaction temperature for the second high-temperature leaching treatment is 120-150℃. The ammonia concentration in the first high-temperature leaching treatment is 1.5-3 mol / L, and the ammonia concentration in the second high-temperature leaching treatment is 4-6 mol / L. The copper ammonia solution is used to remove molybdenum from molybdenum-containing ammonium tungstate solution.

2. The method according to claim 1, characterized in that, The first high-temperature leaching time is 6-10 hours.

3. The method according to claim 1, characterized in that, The ratio of the molar amount of ammonia water in the first high-temperature leaching treatment to the mass of the molybdenum-removed slag is (0.375 mol: 100 g) - (1.2 mol: 100 g).

4. The method according to claim 1, characterized in that, The ratio of the mass of manganese dioxide in the first high-temperature leaching treatment to the mass of the molybdenum-removed slag is (1g:50g) - (1g:100g).

5. The method according to claim 1, characterized in that, The second high-temperature leaching time is 6-12 hours.

6. The method according to claim 1, characterized in that, The ratio of the molar amount of ammonia water in the second high-temperature leaching treatment to the mass of the tungsten-containing copper slag is (0.667 mol: 100 g) - (1.667 mol: 100 g).

7. The method according to claim 1, characterized in that, The ratio of the mass of manganese dioxide in the second high-temperature leaching treatment to the mass of the tungsten-containing copper slag is (1g:45g) - (1g:90g).

8. The method according to claim 1, characterized in that, Using the copper ammonia solution to remove molybdenum from molybdenum-containing ammonium tungstate solution includes: taking the ammonium tungstate solution to be removed from industrial production, adding ammonium sulfide for sulfidation, wherein the amount of ammonium sulfide added is 1.5-2.5 times the amount of molybdenum, then adding 1.5-3 times the amount of molybdenum in copper ammonia solution, stirring at room temperature for 1-2 hours, separating the solid and liquid, and obtaining the solid as the molybdenum-removed slag.