Flaky vanadium pentoxide and preparation method thereof

Abstract

The invention discloses flaky vanadium pentoxide and a preparation method thereof.The method comprises the steps that ammonium vanadate compounds are sequentially subjected to drying dehydration, deamination and oxidation in hot air flow, and hot-state powdery vanadium pentoxide is obtained; the hot-state powdery vanadium pentoxide is rapidly melted in a microwave and / or electric heating mode; and the molten vanadium pentoxide is rapidly cooled and tableted, and the flaky vanadium pentoxide is obtained. Atmospheric flow generated by combustion of coal gas, natural gas and combustion-supporting air can be greatly reduced, and the service life of the melting furnace is prolonged; meanwhile, a large amount of heat energy consumption required by heating a large amount of gas such as coal gas, natural gas and combustion-supporting air in the melting stage can be greatly reduced; the volume of the melting furnace can be reduced by fully utilizing the characteristic that microwave directly and rapidly heats materials, and the construction and maintenance cost of the melting furnace is further reduced.

Description

Technical Field

[0001] This invention relates to the field of vanadium product preparation technology, and in particular to a sheet-like vanadium pentoxide and its preparation method. Background Technology

[0002] Currently, both internationally and domestically, the preparation of flake vanadium pentoxide involves directly heating ammonium vanadate followed by dehydration, deammoniation, oxidation, melting, and flake forming. This process primarily employs either a one-step or three-step method, both using a single heat source such as coal gas, natural gas, electric heating, or microwave heating. The one-step process, compared to the three-step process, suffers from significant drawbacks, including lower production efficiency, lower capacity, lower heat utilization, and lower vanadium yield, and is gradually being phased out. The three-step process has become the dominant production method. However, the three-step process, currently using a single heat source such as coal gas, natural gas, electric heating, or microwave heating, still suffers from issues such as low heat utilization, higher system failure rates, shorter furnace lifespan, and higher system maintenance costs.

[0003] In view of this, improvements should be made to the existing technology. Summary of the Invention

[0004] The main objective of this invention is to provide a method for preparing flake vanadium pentoxide, which employs a multi-heat source for segmented heating. Combining the different material states, characteristics, and correlations in the three-step process (dehydration, deammoniation, oxidation, and melting), the invention proposes a process technology that uses gas flow heating in the dehydration, deammoniation, and oxidation stages, and direct microwave or electric heating in the vanadium powder melting stage. This significantly reduces the atmospheric flow generated by the combustion of coal gas, natural gas, and combustion air, thus extending the service life of the melting furnace. Simultaneously, it greatly reduces the large amount of heat energy consumed during the melting stage due to heating large quantities of coal gas, natural gas, and combustion air. Furthermore, it fully utilizes the direct and rapid heating characteristics of microwaves to reduce the furnace volume, further decreasing the construction and maintenance costs of the melting furnace.

[0005] According to one aspect of the present invention, a method for preparing flake-shaped vanadium pentoxide is provided, comprising: Ammonium vanadate compounds were sequentially dried, dehydrated, deammonized, and oxidized in a hot gas stream to obtain hot powdered vanadium pentoxide. Hot powdered vanadium pentoxide is rapidly melted using microwave and / or electric heating. The molten vanadium pentoxide is rapidly cooled and pressed into sheets to obtain flake vanadium pentoxide.

[0006] According to one embodiment of the present invention, the hot gas flow is provided by direct combustion of the heat source medium.

[0007] According to one embodiment of the present invention, the heat source medium includes coal gas and / or natural gas.

[0008] According to one embodiment of the present invention, hot powdered vanadium pentoxide is directly fed into a melting furnace and then rapidly melted using microwave and / or electric heating.

[0009] According to one embodiment of the present invention, the preparation method is performed in a segmented and serial manner.

[0010] According to one embodiment of the present invention, the drying and dehydration control temperature range is 100~350℃, the deammoniation control temperature range is 300~580℃, the oxidation control temperature range is 300~580℃, and the melting control temperature range is 600~850℃.

[0011] According to one embodiment of the present invention, rapid melting includes melting hot powdered vanadium pentoxide within 1 to 30 minutes, and rapid cooling includes cooling liquid vanadium pentoxide to below 300°C at a cooling rate of ≤2 minutes.

[0012] According to one embodiment of the present invention, the ammonia gas generated in the deammoniation stage is absorbed by the acid washing tower to form an ammonium sulfate solution, which is then evaporated and crystallized to be output as a by-product.

[0013] According to one embodiment of the present invention, tableting is achieved by a double roll crusher and / or a jaw crusher, and the flow rate of liquid vanadium pentoxide is controlled in the range of 800~1600 kg / h.

[0014] According to another aspect of the present invention, a sheet-like vanadium pentoxide is provided, which is prepared by any of the methods mentioned in the above technical solutions.

[0015] According to an embodiment of the present invention, a method for preparing flake vanadium pentoxide is proposed, which employs multiple heat sources for segmented heating. Combining the different material states, characteristics, and correlations in the three-step process (dehydration, deammoniation, oxidation, and melting), a process technology is proposed that uses airflow heating in the dehydration, deammoniation, and oxidation stages, and direct microwave heating in the vanadium powder melting stage. This technology can significantly reduce the atmospheric flow generated by the combustion of coal gas, natural gas, and combustion air, thereby increasing the service life of the melting furnace. Simultaneously, it can greatly reduce the large amount of heat energy consumed during the melting stage due to heating large quantities of coal gas, natural gas, and combustion air. Furthermore, it can fully utilize the characteristics of microwave direct and rapid heating of materials to reduce the furnace volume, further reducing the construction and maintenance costs of the melting furnace. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some implementation examples of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A process flow diagram of a method for preparing sheet-like vanadium pentoxide according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0018] The following detailed description of the embodiments is intended to exemplify the principles of the present invention, but should not be construed as limiting the scope of the invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0019] These embodiments are provided to make this disclosure thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0020] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0022] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0024] like Figure 1 As shown, the present invention provides a method for preparing flake-shaped vanadium pentoxide, comprising: Ammonium vanadate compounds were sequentially dried, dehydrated, deammonized, and oxidized in a hot gas stream to obtain hot powdered vanadium pentoxide. Hot powdered vanadium pentoxide is rapidly melted using microwave and / or electric heating. The molten vanadium pentoxide is rapidly cooled and pressed into sheets to obtain flake vanadium pentoxide.

[0025] Specifically, ammonium vanadate compounds include ammonium polyvanadate, ammonium metavanadate, or a mixture of the two.

[0026] In the method for preparing flake vanadium pentoxide according to an embodiment of the present invention, ammonium vanadate compounds are first dried, dehydrated, deammonized, and oxidized using a hot gas flow. This fully utilizes the large hot gas flow to rapidly remove moisture and decomposed ammonia from the material, while simultaneously oxidizing vanadium oxide to vanadium pentoxide. The oxidized powdered vanadium pentoxide is then fed into a melting furnace for rapid melting using microwave or electric heating. This process fully utilizes the heat energy brought in by the material from the previous stage, while also completely reducing the large amount of heat energy required for heating large quantities of gases such as coal gas, natural gas, and combustion air. This directly reduces the heat energy consumption required for microwave or electric heating and the associated equipment investment costs. Furthermore, this process allows for the reduction of the melting furnace volume by fully utilizing the direct and rapid heating characteristic of microwaves, further reducing the construction and maintenance costs of the melting furnace. On the other hand, using microwave or electric heating during the melting process significantly reduces the atmospheric flow generated by the combustion of coal gas, natural gas, and combustion air, directly reducing the scouring effect of this atmospheric flow on the melting furnace and system, thereby improving the service life of the melting furnace and the system's production efficiency, while also greatly reducing the system's carbon neutralization emissions. The use of this technology can create significant economic benefits and has broad application prospects.

[0027] In some specific embodiments, the hot gas flow is provided by direct combustion of the heat source medium. Direct combustion enables rapid coupling between the heat source and the hot gas flow, reducing intermediate heat exchange links; by precisely controlling the burner flame intensity, the temperature requirements of each stage of drying, deammoniation, and oxidation can be matched in real time, with small temperature fluctuations, avoiding over-burning or under-burning; by adjusting the air / fuel ratio, the oxygen content of the hot gas flow generated by direct combustion can be controlled, promoting the complete oxidation of ammonium vanadate compounds to vanadium pentoxide, reducing the generation of by-products (such as V2O4); the equipment structure is simplified (no steam boiler or heat transfer oil system is required).

[0028] Based on the above embodiments, the heat source medium includes coal gas and / or natural gas. Coal gas (containing CO and H2) and natural gas (mainly CH4) have high calorific value and combustion efficiency of over 90%, which can rapidly heat the gas to the temperature required by the process. The combustion exhaust gas mainly contains CO2 and H2O, which can meet emission standards after simple dust removal, making it more environmentally friendly than coal-based fuels. The gas supply is stable and suitable for continuous production.

[0029] In some specific embodiments, hot powdered vanadium pentoxide is directly fed into a melting furnace and then rapidly melted using microwave and / or electric heating. Direct feeding into the melting furnace avoids the waste of heat energy and activity degradation caused by cooling; microwave heating rapidly increases the core temperature of the powder through volumetric heating, while electric heating supplements the heat at the edges to ensure uniformity, eliminating intermediate cooling and staged heating steps and improving thermal efficiency.

[0030] Based on the above embodiments, the preparation method is implemented in a segmented and series manner. The raw material undergoes continuous drying, dehydration, deammoniation, and oxidation via a hot gas stream (heated by direct combustion of coal gas / natural gas). The hot, powdered vanadium pentoxide is directly conveyed to the melting furnace, where it is rapidly melted using a combination of microwave and electric heating. The molten material is then rapidly cooled and pressed into sheet-like structures. This process eliminates intermediate processing stages, enabling continuous production from raw materials to finished products, and offers both high efficiency and energy savings.

[0031] In some specific embodiments, the drying and dehydration control temperature range is 100~350℃, the deammoniation control temperature range is 300~580℃, the oxidation control temperature range is 300~580℃, and the melting control temperature range is 600~850℃.

[0032] Based on the above embodiments, rapid melting includes melting hot powdered vanadium pentoxide within 1 to 30 minutes, and rapid cooling includes cooling liquid vanadium pentoxide to below 300°C with a cooling rate ≤ 2 minutes.

[0033] In some specific embodiments, the ammonia gas generated during the deammoniation stage is absorbed by an acid washing tower to form an ammonium sulfate solution, which is then evaporated and crystallized to be output as a byproduct. Converting waste gas into a byproduct achieves resource recycling and reduces environmental pollution caused by direct ammonia emissions; the ammonium sulfate can be sold directly as nitrogen fertilizer, offsetting some production costs and improving the economic efficiency of the process.

[0034] Based on the above embodiments, tableting is achieved by a double roll crusher and / or a jaw crusher, and the flow rate of liquid vanadium pentoxide is controlled within the range of 800~1600 kg / h.

[0035] This application also proposes a sheet-like vanadium pentoxide, which is prepared by any of the methods mentioned in the above technical solutions.

[0036] The vanadium pentoxide flakes prepared by the method of this application have high purity and uniform flake structure. The entire process is continuous, with short melting time, which improves production efficiency, high thermal energy utilization, and low energy consumption. The ammonia recovery rate in the deammoniation stage is high, and the by-products can offset part of the production cost, which meets clean production standards. The final product directly meets the needs of high-end alloys, catalysts and energy storage materials, and has the advantages of both quality stability and economy.

[0037] The method of this application can effectively solve the problems of high gas flow rate, high equipment failure rate, large amount of oxidized vanadium powder introduced into the dehydration and deammoniation stages, low vanadium yield, insufficient system thermal energy utilization, high dust removal system pressure, large melting furnace volume, low melting furnace utilization rate, and high melting furnace maintenance cost in systems using a single hot gas flow to dehydrate, deammonize, oxidize, and melt ammonium vanadate to prepare flake vanadium pentoxide. It can also effectively solve the prominent problems of high power consumption, high equipment cost, and insufficient oxidation during the process affecting the vanadium pentoxide grade and other quality deficiencies in systems using a single electric or microwave method to dehydrate, deammonize, oxidize, and melt ammonium vanadate to prepare flake vanadium pentoxide.

[0038] After implementation, this application will have at least the following beneficial effects: (1) It can greatly reduce the atmospheric flow generated by the combustion of coal gas, natural gas and combustion air, directly reduce the impact of the atmospheric flow on the melting furnace and reduce the carbon neutralization emissions of the system, thereby improving the service life of the melting furnace; (2) It can greatly reduce the large amount of heat energy required for heating a large amount of gas such as coal gas, natural gas and combustion air during the melting stage, and directly reduce the investment cost of related equipment required for microwave or electric heating. (3) The characteristics of microwave direct and rapid heating of materials can be fully utilized to reduce the volume of the melting furnace, thereby further reducing the construction and maintenance costs of the melting furnace; (4) It can reduce the risk of vanadium powder being carried into the early dehydration, deammoniation and oxidation stages by the gas flow, thus reducing equipment failure and vanadium loss; (5) It can reduce the amount of impurities brought in by the combustion of large amounts of coal gas, natural gas and combustion air, thereby improving the quality and stability of vanadium pentoxide and greatly improving the system's production efficiency.

[0039] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0040] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for preparing flake-shaped vanadium pentoxide, characterized in that, include: Ammonium vanadate compounds were sequentially dried, dehydrated, deammonized, and oxidized in a hot gas stream to obtain hot powdered vanadium pentoxide. The hot powdered vanadium pentoxide is rapidly melted using microwave and / or electric heating. The molten liquid vanadium pentoxide is rapidly cooled and pressed into tablets to obtain vanadium pentoxide in flake form.

2. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The hot gas flow is provided by the direct combustion of the heat source medium.

3. The method for preparing flake-shaped vanadium pentoxide according to claim 2, characterized in that, The heat source medium includes coal gas and / or natural gas.

4. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The hot powdered vanadium pentoxide is directly fed into the melting furnace and then rapidly melted using microwave and / or electric heating.

5. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The preparation method is performed in a segmented and connected manner.

6. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The drying and dehydration temperature range is 100~350℃, the deammoniation temperature range is 300~580℃, the oxidation temperature range is 300~580℃, and the melting temperature range is 600~850℃.

7. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The rapid melting includes melting the hot powdered vanadium pentoxide within 1 to 30 minutes, and the rapid cooling includes cooling the liquid vanadium pentoxide to below 300°C at a cooling rate of ≤2 minutes.

8. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The ammonia gas generated in the deammoniation stage is absorbed by the acid washing tower to form an ammonium sulfate solution, which is then evaporated and crystallized to be output as a byproduct.

9. The method for preparing flake-shaped vanadium pentoxide according to claim 1, characterized in that, The pressing is achieved by a double-roll crusher and / or a jaw crusher, and the flow rate of the liquid vanadium pentoxide is controlled within the range of 800~1600 kg / h.

10. A sheet-like vanadium pentoxide, characterized in that, It is prepared by the method described in any one of claims 1-9.

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