Method for wet extraction of potassium rhenate from rhenium-containing alloy waste

Abstract

The invention provides a method for wet extraction of potassium rhenate from rhenium-containing alloy waste, which comprises the following steps: (1) pretreating the rhenium-containing alloy waste, mixing the pretreated rhenium-containing alloy waste with a potassium-containing inorganic substance, and reacting in a muffle furnace to obtain a product; and (2) adding water into the product, mixing and stirring, refrigerating in a refrigerator for a period of time, filtering, recrystallizing, and drying to obtain the potassium rhenate. According to the method, the rhenium-containing alloy waste is placed in a muffle furnace to react to generate a rhenium-containing compound, the rhenium-containing compound is separated according to the solubility rule, and the obtained insoluble solid is potassium rhenate; compared with other recovery methods, the method provided by the invention can improve the purity and recovery rate of potassium rhenate.

Description

Technical Field

[0001] The invention relates to the technical field of rare metal recovery, and in particular to a method for wet extracting potassium rhenate from rhenium-containing alloy waste. Background Art

[0002] Rhenium is one of the rarest elements on Earth and is also an extremely dispersed element, with an average abundance of <10 -9 , lower than gold and silver. Due to its high heat resistance, high corrosion resistance, high hardness and mechanical strength, rhenium is widely used in manufacturing, national defense, military industry, aviation industry, petroleum catalysis and electronics. However, rhenium resources are not abundant, and there is no single independent mineral with mining value. Rhenium is usually associated with molybdenum, copper, lead, zinc and other minerals in trace amounts and sparsely, and it is difficult to mine and utilize alone. The rhenium-containing minerals with economic value are molybdenite, molybdenum concentrate and copper concentrate. The rhenium content of molybdenite is between 0.001% and 0.031%, which is the main source of rhenium. With the decreasing rhenium primary mineral resources, the issue of recovering rhenium from rhenium-containing alloy waste has attracted much attention. my country's rhenium resources are scarce. In addition, with the development of the aerospace industry and scientific and technological progress in the fields of chemical industry and medical treatment, the demand for rhenium continues to grow. Therefore, the significance of recovering rhenium from rhenium-containing alloy waste is becoming more and more important.

[0003] Rhenium has unique physical and chemical properties, and its recovery process is usually complicated and difficult. At present, the main technologies for recovering rhenium from rhenium-containing alloy waste are pyrometallurgy and hydrometallurgy. Pyrometallurgy is a method of extracting rhenium by high-temperature treatment of rhenium-containing waste. Pyrometallurgy is carried out under high temperature conditions. During the roasting process, the rhenium in the rhenium-containing waste is easily oxidized to form volatile and water-soluble Re2O7 gas. Re2O7 is leached with ammonia or water, and rhenium is enriched in the solution in the form of ammonium perrhenate or perrhenic acid. Evaporation, concentration and crystallization are carried out to obtain ammonium perrhenate or perrhenic acid crystals, which are finally reduced with hydrogen to obtain metallic rhenium.

[0004] Hydrometallurgy is a metal recovery technology performed in solution and is suitable for extracting rhenium from rhenium-containing waste. The main steps of hydrometallurgy include: Leaching: using oxidizing acids or bases to convert the rhenium in the waste into soluble ReO4 - ; Separation and enrichment: Rhenium is separated and enriched from a rhenium-containing solution through techniques such as solvent extraction, ion exchange or chemical precipitation; Purification: The enriched rhenium needs to be further purified to remove impurities; Reduction: Rhenium compounds are converted into metallic rhenium through chemical reduction methods.

[0005] Among them, molybdenum and rhenium have high and similar melting points. The melting point of molybdenum is about 2620℃, and the melting point of rhenium is 3180℃. They are both high melting point metals. In the separation process, higher temperature and energy are required to melt or change their state, which increases the difficulty and cost of separation, and also puts high demands on the high temperature resistance of the equipment. Therefore, if pyrometallurgy is used to recover rhenium, the process energy consumption is high, harmful gases may be produced, and there is a certain impact on the environment. There are problems such as low tungsten-rhenium separation efficiency, insufficient rhenium recovery rate and purity; hydrometallurgy does not require very high temperature and high temperature resistant equipment, saves energy, and is a sustainable way to recover rhenium. Summary of the invention

[0006] The technical problem to be solved by the present invention is how to provide a method for wet extraction of potassium rhenate from rhenium-containing alloy waste, which can improve the recovery rate of potassium rhenate.

[0007] The present invention solves the above technical problems through the following technical means:

[0008] The present invention provides a method for wet extraction of potassium rhenate from rhenium-containing alloy waste, comprising the following steps:

[0009] (1) pre-treating the rhenium-containing alloy waste, and then mixing the pre-treated rhenium-containing alloy waste with a potassium-containing inorganic substance and placing them in a muffle furnace for reaction to obtain a product;

[0010] (2) adding water to the product, mixing and stirring, placing the product in a refrigerator for a period of time, filtering, recrystallizing, and drying to obtain potassium rhenate.

[0011] Beneficial effects: The present invention places rhenium-containing alloy waste in a muffle furnace for reaction to generate rhenium-containing compounds, separates the rhenium-containing compounds according to the solubility law, and obtains crystals of potassium rhenate; compared with other recovery methods, the present invention can improve the purity and recovery rate of potassium rhenate.

[0012] Preferably, the pretreatment is to wash the rhenium alloy waste with water, acid wash and water, and finally dry it.

[0013] Beneficial effects: The present invention pre-treats the rhenium-containing alloy waste to remove impurities, oil stains and oxides on the surface of the rhenium-containing alloy waste, and the metal surface of the rhenium-containing alloy waste is restored to a relatively pure state, thereby improving the purity of the subsequent extraction of potassium rhenate.

[0014] Preferably, the pickling acid is dilute hydrochloric acid.

[0015] Preferably, the mass ratio of the rhenium-containing alloy waste to the potassium-containing inorganic matter is 1:3.

[0016] Preferably, the potassium-containing inorganic substance is KOH and K2CO3.

[0017] Preferably, the mass ratio of KOH to K2CO3 is 4-5:1.

[0018] Preferably, the reaction temperature is 800-900° C., and the reaction time is 1-2 h.

[0019] Preferably, the heating rate of the reaction temperature is 5 to 10° C. / min.

[0020] Beneficial effects: The present invention can generate an intermediate product that is easier to handle by reacting KOH and K2CO3 with rhenium-containing alloy waste, which is convenient for subsequent separation and purification processes.

[0021] Preferably, the mass ratio of water to product is 3-5:1; and the stirring time is 30 to 120 minutes.

[0022] Preferably, the refrigeration time is 60 to 180 minutes.

[0023] Beneficial effects: The present invention utilizes the different solubility of different compounds in the product in water, and can obtain relatively pure potassium rhenate solid through stirring, refrigeration and filtration. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The tungsten-molybdenum-rhenium alloy waste is used in the embodiment;

[0025] Figure 2 It is the potassium rhenate crystal obtained after filtration in the embodiment;

[0026] Figure 3 is a schematic flow chart of a method for wet extraction of potassium rhenate from rhenium-containing alloy waste in Example 1;

[0027] Figure 4 This is the ICP analysis table of potassium rhenate in Example 1. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0030] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0031] Example 1

[0032] This embodiment provides a method for wet extraction of potassium rhenate from rhenium alloy waste. This embodiment uses tungsten-molybdenum-rhenium alloy waste, and specifically includes the following steps:

[0033] (1) Pre-treat the tungsten-molybdenum-rhenium alloy waste by first placing the tungsten-molybdenum-rhenium alloy waste in a beaker, adding 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, then repeating the above operation with 100 ml of dilute hydrochloric acid, and finally using 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, taking out the tungsten-molybdenum-rhenium alloy waste and putting it into a drying oven for drying.

[0034] (2) Weigh 5 g of the pretreated tungsten-molybdenum-rhenium alloy waste, mix and stir evenly with 12 g of KOH and 3 g of K2CO3, place them in a crucible, and then place the crucible in a muffle furnace for reaction. The heating rate is adjusted to 5°C / min and the peak temperature is 800°C. After reacting at 800°C for 1 hour, the mixture is cooled to room temperature with the furnace and taken out to obtain a product.

[0035] The reaction equation for the chemical reaction in the muffle furnace is shown below:

[0036] 2W+4KOH+3O2=2K2WO4+2H2O (1)

[0037] 2W+2K2CO3+3O2=2K2WO4+2CO2 (2)

[0038] 4Re+2K2CO3+7O2=4KReO4+2CO2 (3)

[0039] 4Re+4KOH+7O2=4KReO4+2H2O (4)

[0040] 2Mo+2K2CO3+3O2=2K2MoO4+2CO2 (5)

[0041] 2Mo+4KOH+3O2=2K2MoO4+2H2O (6)

[0042] (3) The obtained product was added to 60 ml of water and mixed, and heated and stirred in an ultrasonic stirrer for 60 min to fully dissolve it. The heating temperature was 50° C. to obtain a solution.

[0043] (4) Potassium rhenate is separated by using the solubility law. At room temperature: S(K2MoO4=150)>S(K2WO4=100)>>S(KReO4=0.1). Therefore, 60 ml of water is added to the solution. After sufficient shaking, the solution is placed in a refrigerator for 120 minutes. Crystals precipitate during the refrigeration process. The solution is then filtered and the crystals attached to the filter paper are potassium rhenate.

[0044] (5) In order to improve the purity of potassium rhenate, the crystals obtained in step (4) were added with 60 ml of water for dissolution, refrigerated again for 120 min, filtered again, and the crystals attached to the filter paper were placed in a drying oven for drying to obtain potassium rhenate.

[0045] (6) Take 0.02 g of potassium rhenate obtained in step (5) and place it in a beaker. Then add 5 ml of concentrated nitric acid and stir it thoroughly with a glass rod. Prepare the analytical solution at 50 ppm and analyze the precipitate.

[0046] (7) The purity of potassium rhenate was 95.95% and the recovery rate was 88.7%.

[0047] Example 2

[0048] This embodiment provides a method for wet extraction of potassium rhenate from rhenium alloy waste. This embodiment uses tungsten-molybdenum-rhenium alloy waste, and specifically includes the following steps:

[0049] (1) Pre-treat the tungsten-molybdenum-rhenium alloy waste by first placing the tungsten-molybdenum-rhenium alloy waste in a beaker, adding 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, then repeating the above operation with 100 ml of dilute hydrochloric acid, and finally using 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, taking out the tungsten-molybdenum-rhenium alloy waste and putting it into a drying oven for drying.

[0050] (2) Weigh 4 g of the pretreated tungsten-molybdenum-rhenium alloy waste, 12.8 g of KOH and 3.2 g of K2CO3, mix and stir evenly, place in a crucible, and then place the crucible in a muffle furnace for reaction. The heating rate is adjusted to 5°C / min and the peak temperature is 900°C. After reacting at 900°C for 1 hour, the mixture is cooled to room temperature with the furnace and taken out to obtain a product.

[0051] The reaction equation for the chemical reaction in the muffle furnace is shown below:

[0052] 2W+4KOH+3O2=2K2WO4+2H2O (1)

[0053] 2W+2K2CO3+3O2=2K2WO4+2CO2 (2)

[0054] 4Re+2K2CO3+7O2=4KReO4+2CO2 (3)

[0055] 4Re+4KOH+7O2=4KReO4+2H2O (4)

[0056] 2Mo+2K2CO3+3O2=2K2MoO4+2CO2 (5)

[0057] 2Mo+4KOH+3O2=2K2MoO4+2H2O (6)

[0058] (3) The obtained product was added to 60 ml of water and mixed, and heated and stirred in an ultrasonic stirrer for 60 min to fully dissolve it. The heating temperature was 60° C. to obtain a solution.

[0059] (4) Potassium rhenate is separated by using the solubility law. At room temperature: S(K2MoO4=150)>S(K2WO4=100)>>S(KReO4=0.1). Therefore, 60 ml of water is added to the solution. After sufficient shaking, the solution is placed in a refrigerator for 120 minutes. Crystals precipitate during the refrigeration process. The solution is then filtered and the crystals attached to the filter paper are potassium rhenate.

[0060] (5) In order to improve the purity of potassium rhenate, the crystals obtained in step (4) were added with 60 ml of water for dissolution, refrigerated again for 120 min, filtered again, and the crystals attached to the filter paper were placed in a drying oven for drying to obtain potassium rhenate.

[0061] (6) Take 0.02 g of potassium rhenate obtained in step (5) and place it in a beaker. Then add 5 ml of concentrated nitric acid and stir it thoroughly with a glass rod. Prepare the analytical solution at 50 ppm and analyze the precipitate.

[0062] (7) The purity of potassium rhenate was 95.20% and the recovery rate was 81.5%.

[0063] Comparative Example 1

[0064] This comparative example provides a method for wet extraction of potassium rhenate from rhenium alloy waste. This comparative example uses tungsten-molybdenum-rhenium alloy waste, and specifically includes the following steps:

[0065] (1) Pre-treat the tungsten-molybdenum-rhenium alloy waste by first placing the tungsten-molybdenum-rhenium alloy waste in a beaker, adding 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, then repeating the above operation with 100 ml of dilute hydrochloric acid, and finally using 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, taking out the tungsten-molybdenum-rhenium alloy waste and putting it into a drying oven for drying.

[0066] (2) Weigh 4 g of the pretreated tungsten-molybdenum-rhenium alloy waste, 12.8 g of KOH and 3.2 g of K2CO3, mix and stir evenly, place in a crucible, and then place the crucible in a muffle furnace for reaction. The heating rate is adjusted to 5°C / min and the peak temperature is 700°C. After reacting at 700°C for 1 hour, the mixture is cooled to room temperature with the furnace and taken out to obtain a product.

[0067] (3) The obtained product was added to 60 ml of water and mixed, and heated and stirred in an ultrasonic stirrer for 60 min to fully dissolve it. The heating temperature was 60° C. to obtain a solution.

[0068] (4) Potassium rhenate is separated by using the solubility law. At room temperature: S(K2MoO4=150)>S(K2WO4=100)>>S(KReO4=0.1). Therefore, 60 ml of water is added to the solution. After sufficient shaking, the solution is placed in a refrigerator for 120 minutes. Crystals precipitate during the refrigeration process. The solution is then filtered and the crystals attached to the filter paper are potassium rhenate.

[0069] (5) In order to improve the purity of potassium rhenate, the crystals obtained in step (4) were added with 60 ml of water for dissolution, refrigerated again for 120 min, filtered again, and the crystals attached to the filter paper were placed in a drying oven for drying to obtain potassium rhenate.

[0070] (6) Take 0.02 g of potassium rhenate obtained in step (5) and place it in a beaker. Then add 5 ml of concentrated nitric acid and stir it thoroughly with a glass rod. Prepare the analytical solution at 50 ppm and analyze the precipitate.

[0071] (7) The purity of potassium rhenate was 93.72% and the recovery rate was 66.3%.

[0072] The reaction in this comparative example was carried out in a muffle furnace at a reaction temperature of 700°C, which is lower than that in Example 1-2, resulting in incomplete reaction of the metal in the tungsten-molybdenum-rhenium alloy waste with KOH and K2CO3. Although the potassium rhenate obtained had a higher purity, the amount of potassium rhenate was small, so the recovery rate was much reduced.

[0073] Comparative Example 2

[0074] This comparative example provides a method for wet extraction of potassium rhenate from rhenium alloy waste. This comparative example uses tungsten-molybdenum-rhenium alloy waste, and specifically includes the following steps:

[0075] (1) Pre-treat the tungsten-molybdenum-rhenium alloy waste by first placing the tungsten-molybdenum-rhenium alloy waste in a beaker, adding 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, then repeating the above operation with 100 ml of dilute hydrochloric acid, and finally using 100 ml of deionized water, stirring it fully with a glass rod, letting it stand and filtering it, taking out the tungsten-molybdenum-rhenium alloy waste and putting it into a drying oven for drying.

[0076] (2) Weigh 4 g of the pretreated tungsten-molybdenum-rhenium alloy waste, mix and stir evenly with 12.8 g of KOH and 3.2 g of K2CO3, place them in a crucible, and then place the crucible in a muffle furnace for reaction. The heating rate is adjusted to 5°C / min and the peak temperature is 1000°C. After reacting at 1000°C for 1 hour and cooling to room temperature with the furnace, no product can be obtained because the reaction temperature is too high and all the tungsten-molybdenum-rhenium alloy waste is volatilized. Therefore, no product can be obtained.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for wet extraction of potassium rhenate from rhenium-containing alloy waste, characterized in that: The following steps are involved: (1) pre-treating the rhenium-containing alloy waste, and then mixing the pre-treated rhenium-containing alloy waste with a potassium-containing inorganic substance and placing them in a muffle furnace for reaction to obtain a product; (2) adding water to the product, mixing and stirring, placing the mixture in a refrigerator for a period of time, filtering and drying the mixture to obtain potassium rhenate.

2. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 1, characterized in that: The pretreatment is to wash the rhenium alloy waste with water, acid and water, and finally dry it.

3. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 2, characterized in that: The acid used for pickling is dilute hydrochloric acid.

4. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 1, characterized in that: The mass ratio of the pretreated rhenium-containing alloy waste to the potassium-containing inorganic matter is 1:

3.

5. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 4, characterized in that: The potassium-containing inorganic substances are KOH and K2CO3.

6. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 5, characterized in that: The mass ratio of KOH to K2CO3 is 4 to 5:

1.

7. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 1, characterized in that: The reaction temperature is 800-900° C., and the reaction time is 1-2 hours.

8. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 7, characterized in that: The heating rate of the reaction temperature is 5-10°C / min.

9. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 1, characterized in that: The stirring time is 30 to 120 minutes, and heating is performed during stirring at a heating temperature of 50 to 80°C.

10. The method for wet extraction of potassium rhenate from rhenium-containing alloy waste according to claim 1, characterized in that: The refrigeration time is 60 to 180 minutes.

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