Pyrolysis device material for producing high-purity vanadium pentoxide

Abstract

A preparation method of the pyrolysis device material for producing high-purity vanadium pentoxide comprises the following steps: (1) ultrasonic treatment; (2) electric pulse treatment; (3) microwave treatment; and (4) heat treatment is conducted, specifically, the 316 stainless steel plate subjected to microwave treatment in the step (3) is placed in a closed reactor, vacuumizing is conducted, the temperature is increased to 200-300 DEG C, heat preservation is conducted, octanol is added, the octanol exists in a gaseous state, the pressure in the reactor is made to be 1000-2000 Pa, the temperature is kept for 10-30 min, vacuumizing is conducted to discharge the octanol, then the temperature continues to be increased to 850-950 DEG C, heat treatment is conducted, and the 316 stainless steel plate is obtained. Through octanol treatment, octanol can permeate and be adsorbed on the surface of the stainless steel material, the performance of the stainless steel material is improved, element precipitation is resisted, and the performance of the 316 stainless steel is more stable. The problem of impurity element precipitation of the 316 stainless steel material in the prior art is mainly solved through physical means, main chemical components of the stainless steel material are not changed, and the chemical performance of the stainless steel material is hardly influenced.

Description

Technical Field

[0001] The invention relates to the technical field of high-price vanadium production, in particular to a pyrolysis device material for producing high-purity vanadium pentoxide. Background Art

[0002] Ammonium metavanadate, with the molecular formula of NH4VO3, is a white or slightly yellowish crystalline powder with a relative density of 2.326 and a molecular weight of 116.98. It is slightly soluble in cold water, hot ethanol and ether, but soluble in hot water and dilute ammonium hydroxide. It turns into vanadium pentoxide when burned in the air.

[0003] Ammonium metavanadate is an intermediate product of vanadium refining, mainly used to produce vanadium pentoxide (powder or flake), and then further produce metallic vanadium, ferrovanadium alloy or other vanadium-based alloys. It can also be used as a chemical reagent, catalyst, drying agent, mordant, etc. It is widely used as a glaze in the ceramic industry.

[0004] Vanadium is an important reserve metal with a wide range of uses. Vanadium can be added as an additive to metal materials such as steel to enhance the performance of metal materials, and can also be used as a battery material to prepare high-density energy storage materials such as vanadium batteries. It is an indispensable raw material in the fields of aerospace, energy engineering, biomedicine, metal processing, etc. Metallic vanadium is mainly obtained by reducing vanadium compounds such as vanadium pentoxide. In recent years, with the advancement of technology, the industrial production of some downstream high-end vanadium technology products has higher requirements for the quality of vanadium compounds, especially vanadium pentoxide. Especially with the development of vanadium batteries and vanadium energy storage equipment, the domestic supply of high-purity vanadium pentoxide is far from meeting market demand and mainly relies on imports. Therefore, the production of high-purity vanadium pentoxide has broad prospects in my country, and the development of high-purity vanadium pentoxide production technology has great application value and social significance.

[0005] In the process of producing high-purity vanadium pentoxide by pyrolysis of high-purity ammonium metavanadate, other impurities are easily introduced into the device or carrier under high temperature conditions, which seriously affects the product quality. Existing high-purity ammonium metavanadate pyrolysis devices mostly use 316 stainless steel materials. In the national standard, the elements of 316 stainless steel materials are limited as follows (%): SUS316 carbon C≤0.08, manganese Mn≤1.5, silicon Si≤1.5, phosphorus P≤0.04, sulfur S≤0.04, chromium Cr18.00-21.00, nickel Ni 9.00-12.00, molybdenum Mo 2.00-3.00. In order to maintain the performance of 316 stainless steel, the element content therein cannot be easily changed, but in the process of producing high-purity vanadium pentoxide by pyrolysis of high-purity ammonium metavanadate, the part in contact with high-purity ammonium metavanadate will precipitate some impurity elements under long-term high temperature, which will affect the quality of the obtained vanadium pentoxide.

[0006] Therefore, there is an urgent need for a pyrolysis device material for producing high-purity vanadium pentoxide, so that no harmful impurities are precipitated during the reaction process and the quality of the obtained vanadium pentoxide product is not affected. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a pyrolysis device material for producing high-purity vanadium pentoxide, wherein no harmful impurities are precipitated during the pyrolysis reaction of ammonium metavanadate and the quality of the obtained vanadium pentoxide product is not affected.

[0008] The technical solution adopted by the present invention to solve the technical problem is a pyrolysis device material for producing high-purity vanadium pentoxide, and a preparation method thereof comprises the following steps:

[0009] (1) Ultrasound: The 316 stainless steel plate is placed in a closed reactor and subjected to ultrasonic treatment;

[0010] Furthermore, in step (1), the frequency of ultrasound is 2.0-3.0 kHz, and the duration of ultrasound is more than 5 minutes (preferably 8-10 minutes). Too high or too low ultrasound frequency will affect the final effect; too short ultrasound duration will affect the performance of the final product; too long ultrasound duration will not help improve the performance of the finished product, resulting in a waste of energy and an increase in cost, which is unnecessary.

[0011] (2) Electric pulse: using an electric pulse device to perform electric pulse treatment on the 316 stainless steel plate after ultrasonic treatment in step (1);

[0012] Furthermore, in step (2), during the electric pulse treatment process, the output function of the electric pulse device is: f(t) = Ae -αt ; In the formula, A is the amplitude; α is the discharge rate; t is the action time;

[0013] Furthermore, in step (2), when the temperature of the 316 stainless steel plate is raised to 600° C. to 650° C., the electric pulse treatment is started.

[0014] Furthermore, in step (2), during the electric pulse treatment, the pulse voltage is 500V to 1000V, and the pulse frequency is 4Hz to 5Hz.

[0015] Studies have shown that the effect of electric pulse treatment is better when the temperature of 316 stainless steel plate is raised first, and the precipitation of trace elements in the final product at high temperature is less. The present invention can improve the organizational structure of the stainless steel plate and reduce the precipitation of elements in the organization by performing electric pulse treatment and reasonably adjusting the electric pulse treatment parameters.

[0016] (3) Microwave treatment: subjecting the 316 stainless steel plate treated with electric pulses in step (2) to microwave treatment;

[0017] Furthermore, in step (3), the power of the microwave reaction is 400 to 600 W, and the reaction time is 30 to 60 minutes.

[0018] Studies have shown that microwave treatment can shorten the time of subsequent heat treatment, improve efficiency, and make the performance of 316 stainless steel plates more stable.

[0019] (4) Heat treatment: The 316 stainless steel plate subjected to microwave treatment in step (3) is placed in a sealed reactor, evacuated, heated to 200-300° C., kept warm, and octanol is added, wherein the octanol exists in gaseous form, so that the pressure in the reactor is 1000-2000 Pa, maintained for 10-30 minutes, evacuated to remove the octanol, and then continued to heat to 850-950° C. for heat treatment.

[0020] Furthermore, in step (4), the heat treatment time at 850-950°C is ≥ 0.8 min / mm×H, where H is the thickness of the steel plate in mm. The heat treatment time is more preferably 1-2 min / mm×H.

[0021] Research shows that the present invention heats up to 200-300°C after vacuuming, adds octanol, and the octanol exists in the atmosphere in gaseous form at a pressure of 1000-2000 Pa. After the treatment is completed, the octanol is discharged and heat-treated under vacuum. The long-term thermal aging performance of the stainless steel material can be well improved by octanol treatment and heat treatment, and the problem of precipitation of impurity elements can be avoided.

[0022] The present invention uses octanol treatment, and octanol can penetrate and be adsorbed on the surface of the stainless steel material, thereby improving the performance of the stainless steel material, resisting element precipitation, and making the performance of the 316 stainless steel more stable. After the treatment is completed, the octanol can be removed from the system in a vacuum and high-temperature environment.

[0023] The present invention mainly solves the problem of precipitation of impurity elements in 316 stainless steel materials in the prior art by physical means, does not change the main chemical composition of the stainless steel material, and has almost no effect on its chemical properties. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to specific embodiments.

[0025] The raw steel plates used in the embodiments and comparative examples are the same. The raw steel plate 316 stainless steel material has the following element contents (%): SUS316 carbon C is 0.07, manganese Mn is 1.4, silicon Si is 1.3, phosphorus P is 0.03, sulfur S is 0.03, chromium Cr20.00, nickel Ni 10.00, and molybdenum Mo 2.50.

[0026] Example 1

[0027] A pyrolysis device material for producing high-purity vanadium pentoxide, and a preparation method thereof, comprising the following steps:

[0028] (1) Ultrasound: The 316 stainless steel plate is placed in a closed reactor and subjected to ultrasonic treatment;

[0029] In step (1), the ultrasonic frequency is 2.0 kHz and the ultrasonic time is 8 minutes. Too high or too low an ultrasonic frequency will affect the final effect; too short an ultrasonic time will affect the performance of the final product; too long an ultrasonic time will not help improve the performance of the finished product, resulting in a waste of energy and an increase in cost, which is unnecessary.

[0030] (2) Electric pulse: using an electric pulse device to perform electric pulse treatment on the 316 stainless steel plate after ultrasonic treatment in step (1);

[0031] In step (2), during the electric pulse processing, the output function of the electric pulse device is: f(t) = Ae -αt ; In the formula, A is the amplitude; α is the discharge rate; t is the action time;

[0032] In step (2), when the temperature of the 316 stainless steel plate is raised to 600° C., electric pulse treatment is started on it.

[0033] In step (2), during the electric pulse treatment, the pulse voltage is 500V and the pulse frequency is 5Hz.

[0034] Studies have shown that the effect of electric pulse treatment is better when the temperature of 316 stainless steel plate is raised first, and the precipitation of trace elements in the final product at high temperature is less. The present invention can improve the organizational structure of the stainless steel plate and reduce the precipitation of elements in the organization by performing electric pulse treatment and reasonably adjusting the electric pulse treatment parameters.

[0035] (3) Microwave treatment: subjecting the 316 stainless steel plate treated with electric pulses in step (2) to microwave treatment;

[0036] In step (3), the power of the microwave reaction is 600 W and the reaction time is 30 minutes.

[0037] Studies have shown that microwave treatment can shorten the time of subsequent heat treatment, improve efficiency, and make the performance of 316 stainless steel plates more stable.

[0038] (4) Heat treatment: Place the 316 stainless steel plate treated with microwaves in step (3) in a sealed reactor, evacuate the reactor, raise the temperature to 300° C., keep the temperature, add octanol in gaseous form, make the pressure in the reactor 2000 Pa, maintain the pressure for 10 minutes, evacuate the reactor to remove the octanol, and continue to raise the temperature to 950° C. for heat treatment.

[0039] In step (4), the time of heat treatment at 950° C. is 1 min / mm×H, where H is the thickness of the steel plate in mm.

[0040] Research shows that the present invention heats up to 300°C after vacuuming, adds octanol, and the octanol exists in the atmosphere in gaseous form at a pressure of 2000 Pa. After the treatment is completed, the octanol is discharged and heat-treated under vacuum. The long-term thermal aging performance of the stainless steel material can be well improved by octanol treatment and heat treatment, and the problem of precipitation of impurity elements can be avoided.

[0041] The present invention uses octanol treatment, and octanol can penetrate and be adsorbed on the surface of the stainless steel material, thereby improving the performance of the stainless steel material, resisting element precipitation, and making the performance of the 316 stainless steel more stable. After the treatment is completed, the octanol can be removed from the system in a vacuum and high-temperature environment.

[0042] The present invention mainly solves the problem of precipitation of impurity elements in 316 stainless steel materials in the prior art by physical means, does not change the main chemical composition of the stainless steel material, and has almost no effect on its chemical properties.

[0043] Example 2

[0044] A pyrolysis device material for producing high-purity vanadium pentoxide, and a preparation method thereof, comprising the following steps:

[0045] (1) Ultrasound: The 316 stainless steel plate is placed in a closed reactor and subjected to ultrasonic treatment;

[0046] In step (1), the ultrasonic frequency is 3.0 kHz and the ultrasonic time is 10 minutes. Too high or too low ultrasonic frequency will affect the final effect; too short ultrasonic time will affect the performance of the final product; too long ultrasonic time will not help improve the performance of the finished product, resulting in energy waste and cost increase, which is unnecessary.

[0047] (2) Electric pulse: using an electric pulse device to perform electric pulse treatment on the 316 stainless steel plate after ultrasonic treatment in step (1);

[0048] In step (2), during the electric pulse processing, the output function of the electric pulse device is: f(t) = Ae -αt ; In the formula, A is the amplitude; α is the discharge rate; t is the action time;

[0049] In step (2), when the temperature of the 316 stainless steel plate is raised to 650° C., electric pulse treatment is started on the plate.

[0050] In step (2), during the electric pulse treatment, the pulse voltage is 800V and the pulse frequency is 4Hz.

[0051] Studies have shown that the effect of electric pulse treatment is better when the temperature of 316 stainless steel plate is raised first, and the precipitation of trace elements in the final product at high temperature is less. The present invention can improve the organizational structure of the stainless steel plate and reduce the precipitation of elements in the organization by performing electric pulse treatment and reasonably adjusting the electric pulse treatment parameters.

[0052] (3) Microwave treatment: subjecting the 316 stainless steel plate treated with electric pulses in step (2) to microwave treatment;

[0053] In step (3), the power of the microwave reaction is 500 W and the reaction time is 40 minutes.

[0054] Studies have shown that microwave treatment can shorten the time of subsequent heat treatment, improve efficiency, and make the performance of 316 stainless steel plates more stable.

[0055] (4) Heat treatment: Place the 316 stainless steel plate treated with microwaves in step (3) in a sealed reactor, evacuate the reactor, raise the temperature to 200° C., keep the temperature, add octanol in gaseous form, make the pressure in the reactor 1000 Pa, maintain the pressure for 10 to 30 minutes, evacuate the reactor to remove the octanol, and continue to raise the temperature to 850° C. for heat treatment.

[0056] In step (4), the heat treatment time at 850° C. is 2 min / mm×H, where H is the thickness of the steel plate in mm.

[0057] Research shows that the present invention heats up to 200°C after vacuuming, adds octanol, and the octanol exists in the atmosphere in gaseous form at a pressure of 1000 Pa. After the treatment is completed, the octanol is discharged and heat-treated under vacuum. The long-term thermal aging performance of the stainless steel material can be well improved by octanol treatment and heat treatment, and the problem of precipitation of impurity elements can be avoided.

[0058] The present invention uses octanol treatment, and octanol can penetrate and be adsorbed on the surface of the stainless steel material, thereby improving the performance of the stainless steel material, resisting element precipitation, and making the performance of the 316 stainless steel more stable. After the treatment is completed, the octanol can be removed from the system in a vacuum and high-temperature environment.

[0059] The present invention mainly solves the problem of precipitation of impurity elements in 316 stainless steel materials in the prior art by physical means, does not change the main chemical composition of the stainless steel material, and has almost no effect on its chemical properties.

[0060] Example 3

[0061] A pyrolysis device material for producing high-purity vanadium pentoxide, and a preparation method thereof, comprising the following steps:

[0062] (1) Ultrasound: The 316 stainless steel plate is placed in a closed reactor and subjected to ultrasonic treatment;

[0063] In step (1), the ultrasonic frequency is 2.5kHz and the ultrasonic time is 15 minutes. Too high or too low an ultrasonic frequency will affect the final effect; too short an ultrasonic time will affect the performance of the final product; too long an ultrasonic time will not help improve the performance of the finished product, resulting in a waste of energy and an increase in cost, which is unnecessary.

[0064] (2) Electric pulse: using an electric pulse device to perform electric pulse treatment on the 316 stainless steel plate after ultrasonic treatment in step (1);

[0065] In step (2), during the electric pulse processing, the output function of the electric pulse device is: f(t) = Ae -αt ; In the formula, A is the amplitude; α is the discharge rate; t is the action time;

[0066] In step (2), when the temperature of the 316 stainless steel plate is raised to 600° C., electric pulse treatment is started on it.

[0067] In step (2), during the electric pulse treatment, the pulse voltage is 500V and the pulse frequency is 4Hz.

[0068] Studies have shown that the effect of electric pulse treatment is better when the temperature of 316 stainless steel plate is raised first, and the precipitation of trace elements in the final product at high temperature is less. The present invention can improve the organizational structure of the stainless steel plate and reduce the precipitation of elements in the organization by performing electric pulse treatment and reasonably adjusting the electric pulse treatment parameters.

[0069] (3) Microwave treatment: subjecting the 316 stainless steel plate treated with electric pulses in step (2) to microwave treatment;

[0070] In step (3), the power of the microwave reaction is 600 W and the reaction time is 30 minutes.

[0071] Studies have shown that microwave treatment can shorten the time of subsequent heat treatment, improve efficiency, and make the performance of 316 stainless steel plates more stable.

[0072] (4) Heat treatment: The 316 stainless steel plate subjected to microwave treatment in step (3) is placed in a sealed reactor, evacuated, heated to 250° C., kept warm, and octanol is added, wherein the octanol exists in gaseous form, so that the pressure in the reactor is 1500 Pa, maintained for 20 minutes, evacuated to remove the octanol, and then heated to 900° C. for heat treatment.

[0073] In step (4), the time of heat treatment at 900° C. is 1.5 min / mm×H, where H is the thickness of the steel plate in mm.

[0074] Studies have shown that the present invention heats up to 250°C after vacuuming, adds octanol, and the octanol exists in the atmosphere in gaseous form at a pressure of 1500 Pa. After the treatment is completed, the octanol is discharged and heat-treated under vacuum. The long-term thermal aging performance of stainless steel materials can be well improved through octanol treatment and heat treatment, and the problem of precipitation of impurity elements can be avoided.

[0075] The present invention uses octanol treatment, and octanol can penetrate and be adsorbed on the surface of the stainless steel material, thereby improving the performance of the stainless steel material, resisting element precipitation, and making the performance of the 316 stainless steel more stable. After the treatment is completed, the octanol can be removed from the system in a vacuum and high-temperature environment.

[0076] The present invention mainly solves the problem of precipitation of impurity elements in 316 stainless steel materials in the prior art by physical means, does not change the main chemical composition of the stainless steel material, and has almost no effect on its chemical properties.

[0077] Comparative Example 1

[0078] In this comparative example, except that the ultrasonic treatment in step (1) is not performed, other operations and parameters are the same as those in Example 1.

[0079] Comparative Example 2

[0080] In this comparative example, except that the electric pulse treatment in step (2) is not performed, other operations and parameters are the same as those in Example 1.

[0081] Comparative Example 3

[0082] In this comparative example, except that the microwave treatment in step (3) is not performed, other operations and parameters are the same as those in Example 1.

[0083] Comparative Example 4

[0084] In this comparative example, except that the "adding octanol" treatment in step (4) is not performed, other operations and parameters are the same as those in Example 1.

[0085] Comparative Example 5

[0086] In this comparative example, except that step (4) of "continuing to raise the temperature to 950° C. for heat treatment" is not performed, other operations and parameters are the same as those of Example 1.

[0087] Performance test results

[0088] The raw steel plate, the 316 stainless steel plate obtained in Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests, and the test results are shown in Table 1:

[0089] Table 1

[0090]

[0091] As can be seen from Table 1, there is almost no difference in the performance of the raw steel plate and the steel plates of Comparative Examples 1-5 and Examples 1-3, which shows that the operation of the present invention hardly affects the performance of the steel plate itself.

[0092] The raw steel plate, the 316 stainless steel plate obtained in Examples 1-3 and Comparative Examples 1-5 were used as materials for the pyrolysis device to prepare a carrier for the pyrolysis device, which was used to calcine ammonium metavanadate to prepare vanadium pentoxide. The calcination conditions and parameters of each embodiment and comparative example are exactly the same, and the raw materials used are also exactly the same. The specific operation is: calcine ammonium metavanadate in the carrier of the pyrolysis device at a temperature of 550°C for 3 hours to obtain vanadium pentoxide. The purity of the obtained vanadium pentoxide and the content of impurity elements are detected. The results are shown in Table 2.

[0093] Table 2

[0094]

[0095] As can be seen from Table 2, the raw steel plates and the steel plates of Comparative Examples 1-5 used as carrier materials contain chromium, nickel, molybdenum and iron which will precipitate to varying degrees and affect the purity and impurity content of the obtained vanadium pentoxide.

Claims

1. A pyrolysis device material for producing high-purity vanadium pentoxide, characterized in that: The preparation method thereof comprises the following steps: (1) Ultrasound: The 316 stainless steel plate is placed in a closed reactor and subjected to ultrasonic treatment; (2) Electric pulse: using an electric pulse device to perform electric pulse treatment on the 316 stainless steel plate after ultrasonic treatment in step (1); (3) Microwave treatment: subjecting the 316 stainless steel plate treated with electric pulses in step (2) to microwave treatment; (4) Heat treatment: The 316 stainless steel plate subjected to microwave treatment in step (3) is placed in a sealed reactor, evacuated, heated to 200-300° C., kept warm, and octanol is added, wherein the octanol exists in gaseous form, so that the pressure in the reactor is 1000-2000 Pa, maintained for 10-30 minutes, evacuated to remove the octanol, and then continued to heat to 850-950° C. for heat treatment.

2. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1, characterized in that: In the step (1) of the preparation method, the frequency of ultrasound is 2.0 to 3.0 kHz, and the time of ultrasound is more than 5 minutes.

3. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 2, characterized in that: In the step (1) of the preparation method, the ultrasonication time is 8 to 10 minutes.

4. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1 or 2, characterized in that: In the preparation method step (2), during the electric pulse treatment, the output function of the electric pulse device is controlled as follows: f(t)=Ae -αt ; In the formula, A is the amplitude; α is the discharge rate; t is the action time.

5. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1 or 2, characterized in that: In step (2) of the preparation method, when the temperature of the 316 stainless steel plate is raised to 600° C. to 650° C., electric pulse treatment is started on the plate.

6. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1 or 2, characterized in that: In step (2) of the preparation method, during the electric pulse treatment, the pulse voltage is 500V to 1000V and the pulse frequency is 4Hz to 5Hz.

7. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1 or 2, characterized in that: In step (3) of the preparation method, the power of the microwave reaction is 400-600W, and the reaction time is 30-60 minutes.

8. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1 or 2, characterized in that: In step (4) of the preparation method, the heat treatment time at 850-950° C. is ≥0.8 min / mm×H, where H is the thickness of the steel plate in mm.

9. The pyrolysis device material for producing high-purity vanadium pentoxide according to claim 1 or 2, characterized in that: In step (4) of the preparation method, the heat treatment time is 1 to 2 min / mm×H.

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