Method for separating molybdenum and rhenium to prepare high-purity ammonium rhenate

Abstract

The application discloses a method for preparing high-purity ammonium rhenate by separating molybdenum and rhenium, which comprises a reaction device and a reaction process. The reaction device is a T-shaped quartz tube, which is divided into four temperature zones. The first, second and third temperature zones are located in the horizontal tube section of the T-shaped quartz tube, and the fourth temperature zone is the vertical tube section of the T-shaped quartz tube. Oxide raw materials containing molybdenum and rhenium are placed in the first temperature zone. Under the oxygen atmosphere, the high-valence molybdenum and rhenium oxides are separated in the horizontal straight tube by the temperature difference between the temperature zones. The gaseous high-valence rhenium is condensed in the fourth temperature zone to generate high-purity rhenium heptoxide. Under the assistance of high-purity ammonia water, high-purity ammonium rhenate is prepared by cooling and crystallization. The quality of the ammonium rhenate can reach 4N or above.

Description

Technical Field

[0001] This invention relates to a method for preparing high-purity ammonium rhenium by separating molybdenum and rhenium, belonging to the fields of hydrometallurgy and preparation of high-purity chemical raw materials. Background Technology

[0002] Molybdenum and rhenium, as rare, insoluble, and dispersed metals respectively, are extremely important and scarce strategic metals. Rhenium is often found in association with molybdenum, copper, and other metals, particularly in molybdenum concentrate dust, where molybdenum and rhenium exist as oxides and sulfides, respectively. Generally, rhenium in flue dust is transferred to solution through acidic leaching, alkaline leaching, and neutral leaching, thereby achieving molybdenum and rhenium recovery. Few experimental attempts have been made to separate molybdenum and rhenium by utilizing the difference in sublimation temperatures between molybdenum and rhenium oxides. This application, through continuous experimental improvements, utilizes a self-developed multi-temperature zone sublimation furnace to achieve the separation of molybdenum and rhenium oxides and obtain high-purity ammonium rhenate with a purity of 4N or higher. Summary of the Invention

[0003] The purpose of this invention is to provide a method for separating molybdenum and rhenium to prepare high-purity ammonium perlite, so as to ensure that the sublimation temperature difference between the high-valence oxides of molybdenum and rhenium can be used to simultaneously achieve the separation of molybdenum and rhenium and the preparation of high-purity ammonium perlite.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for preparing high-purity ammonium rhenium by separating molybdenum and rhenium includes the following steps:

[0006] 1) Take a reaction apparatus, which includes a T-shaped quartz tube. The T-shaped quartz tube consists of a horizontal section and a vertical section. One end of the horizontal section is connected to a sealed quartz tube with a gas inlet via a flange. The sealed quartz tube is filled with O-ring ceramic rings. The other end is connected to the middle of the vertical section, and the connection opening is narrowed. The horizontal section is also equipped with multiple ceramic alumina tube plugs, which divide the horizontal section into three temperature zones along the gas flow direction, from left to right: the first temperature zone, the second temperature zone, and the third temperature zone. The first temperature zone, the second temperature zone, and the third temperature zone are respectively equipped with heating devices for the first temperature zone, the second temperature zone, and the third temperature zone. The entire vertical section forms a fourth temperature zone, and a heating device for the fourth temperature zone is installed on the outside of the vertical section. The top of the vertical section is connected to a tube plug plate via a flange. A serpentine condenser tube, a gas venting pipe, and an ammonia inlet pipe are inserted into the tube plug plate. The bottom of the vertical section is connected to a liquid discharge pipe.

[0007] The first temperature zone heating device, the second temperature zone heating device, the third temperature zone heating device and the fourth temperature zone heating device all adopt laboratory tubular electric heating furnaces or electric heating jackets;

[0008] 2) Take a sample-carrying quartz boat and add a mixture containing molybdenum and rhenium oxide into the sample-carrying quartz boat. Then place the sample-carrying quartz boat filled with the mixture into the first temperature zone of the horizontal section of the T-shaped quartz tube.

[0009] 3) After verifying the airtightness of the reaction apparatus, oxygen is introduced into the T-shaped quartz tube through the gas inlet. Simultaneously, the heating devices for the first, second, third, and fourth temperature zones are activated to preheat the entire system to 100-150°C. After 30-60 minutes, compressed air is introduced into the serpentine condenser, and the temperatures of the first to fourth temperature zones are set to 380-420°C, 350-390°C, 430-470°C, and 350-390°C, respectively. The first temperature zone is used to sublimate high-valence rhenium oxide; the second temperature zone is used to deposit and separate some of the impurities of molybdenum oxide; the third temperature zone is used to ensure that rhenium oxide can enter the fourth temperature zone in a gaseous state; and the fourth temperature zone is used to prevent low-boiling-point impurities from crystallizing, thereby improving the purity of the rhenium oxide.

[0010] 4) After reacting for 1-2 hours, each temperature zone is cooled at a rate of 3-8℃ / min. When the fourth temperature zone drops below 60℃, oxygen is replaced with nitrogen and ammonia is introduced into the fourth temperature zone through the ammonia inlet pipe until the solid is completely dissolved. Cooling to below 60℃ is to prevent cold liquid ammonia from entering the system and avoiding large local temperature differences in the quartz tube, which could lead to equipment damage. At the same time, using liquid ammonia to dissolve rhenium heptoxide directly converts it into ammonium perrhenate, simplifying the traditional preparation steps of dissolving in water to generate perrhenic acid and adjusting the pH with ammonia to prepare ammonium perrhenate.

[0011] 5) Adjust the temperature of the fourth temperature zone to 90℃ to slowly evaporate the solvent until almost no droplets appear at the outlet of the gas vent pipe. Then, open the valve on the liquid discharge pipe and discharge the liquid from the device while it is still hot. Cool and crystallize to obtain high-purity ammonium perrhenate with a purity of 4N or higher. Evaporation at 90℃ is to prevent the liquid from boiling violently, which would cause the crystallized ammonium perrhenate to splash onto the quartz surface and result in material loss. Molybdenum oxide exists as a high-boiling-point oxide on the quartz sample boat and horizontal quartz tube.

[0012] The purification principle of this invention is as follows: This invention combines sublimation and crystallization methods to purify and prepare ammonium perrhenate from molybdenum rhenium oxide dust. Sublimation is carried out in horizontal and vertical tubes using a T-shaped quartz tube and a tubular furnace, respectively, and then rhenium heptaoxide crystals are obtained in the vertical tube. After the crystals are dissolved in ammonia water, they are transformed into ammonium perrhenate, and then high-purity ammonium perrhenate is generated by crystallization using the saturated solubility of ammonium perrhenate.

[0013] In summary, this invention, based on traditional sublimation and crystallization methods, develops a method for recovering molybdenum and rhenium from smelting dust containing molybdenum and rhenium, and prepares high-purity ammonium perrhenate. This transforms the high-value-added rhenium within the dust from rhenium dioxide into high-purity ammonium perrhenate, a raw material for high-purity rhenium production. This method differs from purely wet processing by incorporating sublimation, simplifying the separation and extraction steps of molybdenum and rhenium smelting dust, and improving the efficiency and purity of rhenium recovery. Attached Figure Description

[0014] Figure 1 The present invention relates to a reaction apparatus for purifying and preparing high-purity ammonium perrylate.

[0015] In the diagram, 1-O-type ceramic ring, 2-sealing quartz tube, 3-T-shaped quartz tube, 4-first temperature zone heating device, 5-sample quartz boat, 6-second temperature zone heating device, 7-third temperature zone heating device, 8-pipe plug plate, 9-fourth temperature zone heating device, 10-liquid discharge pipe, 11-serpentine condenser, 12-gas vent pipe, 13-ammonia water inlet pipe, 14-connecting port, 15-ceramic alumina pipe plug, 16-gas inlet. Detailed Implementation

[0016] like Figure 1 As shown, the reaction apparatus for purifying and preparing high-purity ammonium rhenium oxide according to the present invention includes a T-shaped quartz tube 3, which consists of a horizontal section and a vertical section. One end of the horizontal section is connected to a sealed quartz tube 2 with a gas inlet 16 via a flange. The sealed quartz tube 2 is also filled with an O-ring ceramic ring 1. The other end of the horizontal section is connected to the middle of the vertical section, and the connection opening 14 is narrowed. The horizontal section is also equipped with multiple ceramic alumina plugs 15, which divide the horizontal section into three temperature zones along the gas flow direction. From left to right, the three temperature zones are designated as the first, second, and third temperature zones. Heating devices 4, 6, and 7 are respectively installed on the outer sides of the first, second, and third temperature zones. The entire vertical pipe section forms the fourth temperature zone, and a heating device 9 for the fourth temperature zone is installed on the outer side of the vertical pipe section. A pipe plug plate 8 is connected to the top of the vertical pipe section via a flange. A serpentine condenser pipe 11, a gas vent pipe 12, and an ammonia inlet pipe 13 are inserted into the pipe plug plate 8. A liquid discharge pipe 10 is connected to the bottom of the vertical pipe section.

[0017] The heating devices 4 (first temperature zone), 6 (second temperature zone), 7 (third temperature zone), and 9 (fourth temperature zone) all use laboratory electric heating jackets.

[0018] In the above-mentioned device structure, fluororubber or asbestos is used as sealing gasket at each port connection flange to ensure the airtightness of the entire reaction device; the function of the O-ring ceramic ring 1 is to disperse the gas, reduce the gas flow rate, and allow the gas to pass through the quartz tube smoothly and disorderly, thereby reducing the gas interference with sublimation separation and preventing the molybdenum oxide particles from entering the vertical tube and splashing the sample in the quartz boat caused by the gas passing through the horizontal tube in the form of central turbulence; the connecting port 14 is narrowed to prevent the sublimation gas entering the vertical tube from flowing back into the horizontal tube.

[0019] The purification process of the present invention will be explained below with reference to specific embodiments.

[0020] Example 1

[0021] use Figure 1 The reaction apparatus shown purifies 50 g of a molybdenum oxide-rhenium mixture (molybdenum trioxide: rhenium dioxide = 80%: 20%, mass ratio), controlling the atmospheric gas flow rate at 50 L / h and the condensate gas flow rate at 1.5 m / s. 3 / h. The specific steps are as follows:

[0022] 1) Take the sample-carrying quartz boat 5 and add molybdenum oxide rhenium mixture into the sample-carrying quartz boat 5. Then place the loaded sample-carrying quartz boat 5 into the first temperature zone of the horizontal section of the T-shaped quartz tube 3.

[0023] 2) After the airtightness check is confirmed to be correct, high-purity oxygen is introduced into the T-shaped quartz tube 3 through the gas inlet 16 as an atmosphere gas. At the same time, the heating devices 4, 6, 7 and 9 of the first temperature zone are turned on to preheat the entire system to 150°C. After 30 minutes, condensing gas (compressed air) is introduced into the serpentine condenser tube 11 and the temperatures of the first to fourth temperature zones are set to 420°C, 390°C, 470°C and 390°C respectively.

[0024] 4) After the equipment has reached the set temperature and run stably for 1.5 hours, cool each temperature zone at a rate of 3~8℃ / min. When the fourth temperature zone drops below 60℃, replace the high-purity oxygen (99.9%) with high-purity nitrogen (99.9%) and introduce high-purity ammonia (30% concentration) into the fourth temperature zone through ammonia inlet pipe 13 until the solid is completely dissolved.

[0025] 5) Adjust the temperature of the fourth temperature zone to 90℃ to slowly evaporate the solvent until there are basically no liquid droplets at the outlet of the gas venting pipe 12. Then open the valve on the liquid discharge pipe 10 and discharge the liquid from the device while it is still hot. Cool and crystallize to obtain high-purity ammonium rheniumate. Analysis shows that the purity of NH4ReO4 can reach 99.99%.

[0026] 6) Turn off the power to the reaction equipment and shut off the gas. After the device cools to room temperature, collect the residue in the quartz boat. The purity of the molybdenum trioxide remaining in the quartz boat can reach 99.95%.

[0027] Example 2

[0028] use Figure 1 The reaction apparatus shown purifies 1000g of rhenium and molybdenum-containing flue dust (40% molybdenum, 0.15% rhenium) obtained from molybdenum concentrate smelting in four stages, controlling the atmospheric gas flow rate at 10 L / h and the condensate gas flow rate at 2.5 m. 3 / h. The specific steps are as follows:

[0029] 1) Take the sample-carrying quartz boat 5 and add rhenium and molybdenum-containing ash into the sample-carrying quartz boat 5. Then place the loaded sample-carrying quartz boat 5 into the first temperature zone of the horizontal section of the T-shaped quartz tube 3.

[0030] 2) After the airtightness check is confirmed to be correct, high-purity oxygen is introduced into the T-shaped quartz tube 3 through the gas inlet 16 as an atmosphere gas. At the same time, the heating devices 4, 6, 7 and 9 of the first temperature zone are turned on to preheat the entire system to 120°C. After 60 minutes, condensing gas (compressed air) is introduced into the serpentine condenser tube 11 and the temperatures of the first to fourth temperature zones are set to 410°C, 365°C, 430°C and 390°C respectively.

[0031] 4) After the equipment has reached the set temperature and run stably for 1.5 hours, cool each temperature zone at a rate of 3~8℃ / min. After the system temperature drops to room temperature, replace the smelting ash from the molybdenum concentrate and repeat steps 1) to 4) three times.

[0032] 5) When the fourth temperature zone drops below 60℃, replace the high-purity oxygen with high-purity nitrogen and introduce high-purity ammonia (30%) into the fourth temperature zone through ammonia inlet pipe 13 until the solid is completely dissolved; adjust the temperature of the fourth temperature zone to 90℃ to slowly evaporate the solvent until there are basically no liquid droplets at the outlet of gas vent pipe 12, then open the valve on liquid discharge pipe 10 and discharge the liquid from the device while it is hot, cool and crystallize to obtain high-purity ammonium rheniumate; analysis shows that the purity of NH4ReO4 can reach 99.995%;

[0033] 6) Turn off the power to the reaction equipment and shut off the gas. After the device cools to room temperature, collect the residue in the quartz boat. The purity of the molybdenum trioxide remaining in the quartz boat can reach 65%, and it also contains 32% silicon dioxide.

Claims

1. A method for preparing high-purity ammonium rhenium by separating molybdenum and rhenium, characterized in that, Includes the following steps: 1) Take the reaction apparatus, which includes a T-shaped quartz tube (3). The T-shaped quartz tube (3) consists of a horizontal section and a vertical section. One end of the horizontal section is connected to a sealed quartz tube (2) with a gas inlet (16) via a flange, and the other end is connected to the middle of the vertical section with the connection port (14) being narrowed. The horizontal section is also equipped with multiple ceramic alumina plugs (15), which divide the horizontal section into three temperature zones along the gas flow direction, from left to right: the first temperature zone, the second temperature zone, and the third temperature zone. The third temperature zone is provided with heating devices (4), (6) and (7) for the first, second and third temperature zones respectively. The entire vertical pipe section forms the fourth temperature zone, and heating devices (9) for the fourth temperature zone are provided on the outside of the vertical pipe section. A pipe plug plate (8) is connected to the top of the vertical pipe section through a flange. A serpentine condenser (11), a gas vent pipe (12) and an ammonia inlet pipe (13) are inserted into the pipe plug plate (8). A liquid discharge pipe (10) is connected to the bottom of the vertical pipe section. 2) Take a sample-carrying quartz boat (5) and add a mixture containing molybdenum rhenium oxide into the sample-carrying quartz boat (5). Then place the loaded sample-carrying quartz boat (5) into the first temperature zone of the horizontal section of the T-shaped quartz tube (3). 3) After the airtightness of the reaction device is checked and found to be correct, oxygen is introduced into the T-shaped quartz tube (3) through the gas inlet (16). At the same time, the heating devices of the first temperature zone (4), the second temperature zone (6), the third temperature zone (7) and the fourth temperature zone (9) are turned on to heat the entire system to 100~150℃ for preheating treatment. After 30~60 minutes, compressed air is introduced into the serpentine condenser (11) and the temperatures of the first temperature zone to the fourth temperature zone are set to 380~420℃, 350~390℃, 430~470℃ and 350~390℃ respectively. 4) After the reaction has been going on for 1 to 2 hours, the temperature of each zone is cooled at a rate of 3 to 8 °C / min. When the fourth zone is cooled to below 60 °C, the oxygen is replaced with nitrogen and ammonia is introduced into the fourth zone through the ammonia inlet pipe (13) until the solid is completely dissolved. 5) Adjust the temperature of the fourth temperature zone to 90°C to slowly evaporate the solvent until there are basically no liquid droplets at the outlet of the gas venting pipe (12). Then open the valve on the liquid discharge pipe (10) and discharge the liquid out of the device while it is hot. Cool and crystallize to obtain high-purity ammonium rhenium with a purity of 4N or higher.

2. The method for preparing high-purity ammonium rhenium by separating molybdenum and rhenium as described in claim 1, characterized in that, In step 1), the sealing quartz tube (2) is filled with an O-ring ceramic ring (1).

3. The method for preparing high-purity ammonium rhenium by separating molybdenum and rhenium as described in claim 1, characterized in that, In step 1), the first temperature zone heating device (4), the second temperature zone heating device (6), the third temperature zone heating device (7) and the fourth temperature zone heating device (9) all adopt laboratory tubular electric heating furnaces or electric heating jackets.

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