Room-temperature preparation method of vanadyl oxalate

Abstract

The invention provides a room-temperature preparation method of vanadyl oxalate, which comprises the following steps: mixing submillimeter powdery vanadium pentoxide with certain granularity and oxalic acid according to a certain molar ratio, adding a small amount of water, and stirring to obtain a mixture; and keeping the mixture at room temperature for 32-84 hours to obtain a solid vanadyl oxalate product. A certain raw material granularity and a proper amount of water are controlled, the small-scale effect, the interface effect and the time-temperature equivalence principle of the raw materials are utilized, the addition of the proper amount of water is beneficial to the fusion reaction of the surfaces of the small-size particles, the reaction energy barrier is reduced, and the reaction kinetics is improved; through mutual cooperation, the solid-phase reaction temperature can be reduced to the room temperature (such as 20-25 DEG C), lower-temperature and ultralow-energy-consumption preparation of vanadyl oxalate is successfully achieved, irritant oxalic acid steam volatilization is avoided, environmental protection is achieved, no three wastes are generated, and the product yield and purity are guaranteed.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to a method for preparing vanadyl oxalate at room temperature. Background Art

[0002] Vanadium is an important raw material that is indispensable for the development of modern industry, national defense and science and technology. Vanadium-based compounds have key uses in many fields such as metallurgy, new energy, new materials, catalysts, electronics, etc. Vanadyl oxalate, as a highly water-soluble, low-priced organic vanadium compound, is a basic vanadium chemical raw material and an intermediate raw material for the preparation of high-performance vanadium products including vanadium dioxide.

[0003] The common vanadium oxalate in the market today is sold in the form of aqueous solution, with a small proportion of solid products and a high price. The currently publicly reported vanadium oxalate preparation method usually uses oxalic acid and vanadium pentoxide to react in an aqueous phase to generate a crude vanadium oxalate aqueous solution product, and then filters the solid particles and adds water to adjust the concentration to obtain a vanadium oxalate solution product. To obtain a solid vanadium oxalate product, it is generally necessary to go through heating concentration, cooling crystallization, separation, drying and other processes. However, the process is complicated, energy-intensive, and time-consuming, and the high concentration of vanadium oxalate at the wall of the reactor is easily decomposed or carbonized during thermal concentration, affecting the product quality. On the other hand, the traditional solid-phase reaction preparation method requires a higher reaction temperature to overcome the energy barrier required for the reaction. The reaction temperature is generally above 100°C (100-200°C), or stirring is required to ensure that the reaction is complete. However, too high a temperature can easily lead to the volatilization of oxalic acid or the decomposition and discoloration of vanadium oxalate. Summary of the invention

[0004] In view of this, the present invention provides a room temperature preparation method of vanadium oxalate. The preparation method of the present invention can reduce the solid phase reaction temperature to room temperature (such as 20-25°C), successfully achieves a lower temperature and ultra-low energy consumption preparation of vanadium oxalate and avoids the volatilization of irritating oxalic acid vapor, is environmentally friendly and does not produce three wastes.

[0005] The present invention provides a room temperature preparation method of vanadyl oxalate, comprising:

[0006] A) mixing submillimeter powdered vanadium pentoxide, oxalic acid and water, and stirring to obtain a mixture;

[0007] in,

[0008] The sub-millimeter powdered vanadium pentoxide has a particle size distribution of 0.01 to 0.5 mm and an average particle size of 0.02 to 0.2 mm;

[0009] B) keeping the mixture at room temperature for 32 to 84 hours to obtain a solid vanadyl oxalate product.

[0010] Preferably, in step A), the molar ratio of vanadium pentoxide to oxalic acid is 1:(2.8-3.2).

[0011] Preferably, in step A), the molar ratio of vanadium pentoxide to oxalic acid is 1:3.0.

[0012] Preferably, in step A), the amount of water used is 5% to 20% of the total mass of the vanadium pentoxide and oxalic acid.

[0013] Preferably, step B) specifically comprises:

[0014] The mixture is kept at room temperature for 8 to 36 hours, the material is scraped flat to a thickness of 1 to 2 cm and then air-dried at room temperature for 1 to 2 days to obtain a solid vanadyl oxalate product.

[0015] Preferably, step B) specifically comprises: scraping the mixture discharge to a thickness of 1 to 2 cm and air-drying at room temperature for 32 to 84 hours to obtain a solid vanadyl oxalate product.

[0016] Preferably, in step B), after keeping the mixture at room temperature for 32 to 84 hours, the method further comprises: crushing or grinding.

[0017] Preferably, in step A), the stirring speed is 10 to 60 rpm and the stirring time is 5 to 20 min.

[0018] Preferably, the container used in step B) is a static container, or a stirring or drum reactor.

[0019] Preferably, the container material / lining used in step B) is plastic, enamel, ceramic or corrosion-resistant metal.

[0020] The present invention provides a room temperature preparation method of vanadium oxalate, which is a method for preparing vanadium oxalate under ultra-low energy consumption and room temperature conditions. The method first mixes submillimeter powdered vanadium pentoxide of a certain particle size and oxalic acid according to a certain molar ratio, and adds a small amount of water to stir to obtain a mixture; then the mixture is kept at room temperature for 32 to 84 hours to obtain a solid vanadium oxalate product. The present invention controls a certain raw material particle size and an appropriate amount of water, utilizes the small-scale effect, interface effect and time-temperature equivalence principle of the raw materials, and the addition of an appropriate amount of water is conducive to the dissolution reaction on the surface of small-sized particles, reduces the reaction energy barrier, and improves the reaction kinetics; the above mutually cooperates to reduce the solid phase reaction temperature to room temperature (such as 20 to 25° C.), successfully realizes the preparation of vanadium oxalate at a lower temperature and ultra-low energy consumption, avoids the volatilization of irritating oxalic acid vapor, is environmentally friendly and does not produce three wastes, and ensures the product yield and purity. Therefore, it will have important technical value and market prospects in the fields of vanadium chemical industry and vanadium-based new materials. The process is simple in procedure, mild in conditions, ultra-low in energy consumption, and highly extensible, and is suitable for large-scale production. This technology breaks through the general thinking of ordinary technicians, breaks the technical prejudice of traditional chemical preparation, overcomes the shortcomings of existing synthesis / preparation technology, solves long-standing related technical problems, and achieves unexpected results.

[0021] The experimental results show that the present invention successfully prepares solid vanadium oxalate product under room temperature conditions, and the yield is above 95% and the purity is above 98%, thus ensuring a better preparation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0023] Figure 1 The XRD diagram of the vanadium pentoxide raw material used in the present invention;

[0024] Figure 2 is the XRD pattern of the oxalic acid raw material used in the present invention;

[0025] Figure 3 This is the XRD pattern of the solid vanadyl oxalate product obtained in Example 1;

[0026] Figure 4 This is the XRD pattern of the solid vanadium oxalate product obtained in Example 2. DETAILED DESCRIPTION

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0028] In this article, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0029] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] Herein, when it comes to numerical ranges, unless otherwise specified, the numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0031] In this article, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 0.01-0.5mm means that the units of the left endpoint "0.01" and the right endpoint "0.5" are both mm.

[0032] Only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0033] The present invention provides a room temperature preparation method of vanadyl oxalate, comprising:

[0034] A) mixing submillimeter powdered vanadium pentoxide, oxalic acid and water, and stirring to obtain a mixture;

[0035] in,

[0036] The sub-millimeter powdered vanadium pentoxide has a particle size distribution of 0.01 to 0.5 mm and an average particle size of 0.02 to 0.2 mm;

[0037] B) keeping the mixture at room temperature for 32 to 84 hours to obtain a solid vanadyl oxalate product.

[0038] [About Step A]:

[0039] A) Submillimeter powdered vanadium pentoxide, oxalic acid and water are mixed and stirred to obtain a mixture.

[0040] In the present invention, the particle size distribution of the submillimeter powdered vanadium pentoxide is 0.01-0.5 mm, and the average particle size is 0.02-0.2 mm. The average particle size can be specifically 0.02 mm, 0.05 mm, 0.1 mm, 0.15 mm, and 0.2 mm. The above particle size is one of the keys to the realization of the present invention. The present invention controls the above particle size to facilitate the room temperature reaction. If the particle size is too large, the reaction is slow or affects the sufficiency of the reaction. The present invention has no special restrictions on the source of the submillimeter powdered vanadium pentoxide, and it can be a commercial product.

[0041] In the present invention, the source of the oxalic acid is not particularly limited and can be any commercial product.

[0042] In the present invention, the molar ratio of vanadium pentoxide to oxalic acid is preferably 1:(2.8-3.2), specifically 1:2.8, 1:2.9, 1:3.0, 1:3.1, 1:3.2, and more preferably 1:3.0.

[0043] In the present invention, a small amount of water is added to the raw material, and the amount of water is preferably 5% to 20% of the total mass of the vanadium pentoxide and oxalic acid, and can be specifically 5%, 10%, 15%, and 20%. Adding an appropriate amount of water in this process is beneficial to the dissolution reaction on the surface of small-sized particles, reduces the reaction energy barrier, and improves the reaction kinetics. If the amount of water is too little, it will have an adverse effect on the reaction, and if the amount of water is too much, it will affect the subsequent treatment, which is not conducive to the stable acquisition of solid vanadium oxalate products and the guarantee of their yield and purity.

[0044] In the present invention, the order of mixing submillimeter powdered vanadium pentoxide, oxalic acid and water is preferably: first mix the submillimeter powdered vanadium pentoxide and oxalic acid, and then add water. After all materials are in contact, they are stirred. Wherein, the stirring speed is preferably 10 to 60 rpm, specifically 10 rpm, 20 rpm, 30 rpm, 40 rpm, 50 rpm, 60 rpm. The stirring time is preferably 5 to 20 min, specifically 5 min, 10 min, 15 min, 20 min. After the above stirring, a wet powder or slurry mixture is obtained.

[0045] [About step B]:

[0046] B) keeping the mixture at room temperature for 32 to 84 hours to obtain a solid vanadyl oxalate product.

[0047] In the present invention, the room temperature condition is preferably 20-25°C, specifically 20°C, 21°C, 22°C, 23°C, 24°C, or 25°C.

[0048] In the present invention, in the first mode, the step B) preferably specifically includes: keeping the mixture at room temperature for 8 to 36 hours, scraping the material to a thickness of 1 to 2 cm, and then air-drying at room temperature for 1 to 2 days to obtain a solid vanadium oxalate product. Wherein, first keep it at room temperature for 8 to 36 hours, specifically 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, 32 hours, 34 hours, 36 hours. The material is scraped to 1 to 2 cm, that is, the material is scraped thin, and the thickness can be specifically 1 cm, 1.5 cm, 2 cm. After scraping, continue to air-dry at room temperature for 1 to 2 days, specifically 1 day or 2 days. The room temperature air-drying is to dry naturally at room temperature. After the above treatment, a blue solid vanadium oxalate product is obtained.

[0049] In the present invention, the second method, the step B) preferably specifically includes: scraping the mixture to a thickness of 1 to 2 cm and air-drying it at room temperature for 32 to 84 hours to obtain a solid vanadium oxalate product. Among them, the discharge is scraped to 1 to 2 cm, that is, the material is scraped thin, and the thickness can be specifically 1 cm, 1.5 cm, or 2 cm. After scraping, it is air-dried at room temperature for 32 to 84 hours, specifically 32 hours, 2 days, 3 days, or 84 hours. The room temperature air-drying is to dry naturally at room temperature. After the above treatment, a blue solid vanadium oxalate product is obtained. Compared with the first method, it is equivalent to combining two room temperature placements into one (that is, combining the reaction and air-drying into one). After obtaining the mixture in step A), the discharge is directly scraped and air-dried at room temperature.

[0050] In the present invention, in step B), the room temperature is maintained for 32 to 84 hours to allow the material to react at low temperature. The container used can be a static container, or a stirring or drum reactor. The reaction vessel can be plastic, enamel, ceramic, corrosion-resistant metal, or a conventional material container equipped with a coating of the above materials (i.e. plastic, enamel, ceramic or corrosion-resistant metal) (e.g. iron can + enamel coating, but not limited to this). That is, the material / lining of the reactor can be plastic, enamel, ceramic, corrosion-resistant metal; that is to say, the material of the reactor can be the above types, or the lining of the reactor can be the above types (equivalent to the tank body being equipped with the above types of coatings).

[0051] In the present invention, after the mixture is kept at room temperature for 32 to 84 hours, it is preferably further subjected to: crushing or grinding. The present invention has no particular limitation on the method of crushing or grinding, which may be any conventional method in the art.

[0052] The chemical principle of the present invention is that oxalic acid and vanadium pentoxide generate vanadyl oxalate through enhanced interface chemical reaction and time-temperature equivalence principle. The reaction formula is as follows:

[0053] H 2 C 2 O 4 ·nH 2 O+V 2 O 5 →VOC 2 O 4 ·xH 2 O+H 2 O+CO 2 ↑

[0054] As the reaction proceeds to the right, the gas and / or water gradually evaporates to obtain a vanadyl oxalate paste or solid product. The product obtained in the present invention is vanadyl oxalate pentahydrate VOC 2 O 4 ·5H 2 O product.

[0055] The present invention provides a method for preparing vanadium oxalate, firstly mixing submillimeter powdered vanadium pentoxide of a certain particle size and oxalic acid in a certain molar ratio, adding a small amount of water, and stirring to obtain a mixture; then keeping the mixture at room temperature for 32 to 84 hours to obtain a solid vanadium oxalate product. The present invention controls a certain raw material particle size and an appropriate amount of water, utilizes the small-scale effect, interface effect and time-temperature equivalence principle of the raw materials, and the addition of an appropriate amount of water is conducive to the dissolution reaction on the surface of small-sized particles, reduces the reaction energy barrier, and improves the reaction kinetics; the above mutually cooperates, and the solid phase reaction temperature can be reduced to room temperature (such as 20 to 25°C), successfully realizing the preparation of vanadium oxalate at a lower temperature and ultra-low energy consumption, and avoiding the volatilization of irritating oxalic acid vapor, which is environmentally friendly and does not produce three wastes, and ensures the product yield and purity. Therefore, it will have important technical value and market prospects in the field of vanadium chemical industry and vanadium-based new materials. The process is simple in procedure, mild in condition, ultra-low in energy consumption, and highly extensible, and is suitable for large-scale production. This technology breaks through the general thinking of ordinary technicians, breaks the technical prejudice of traditional chemical preparation, overcomes the shortcomings of existing synthesis / preparation technology, solves long-standing related technical problems, and achieves unexpected results.

[0056] The vanadyl oxalate product prepared by the present invention can be used to prepare downstream vanadium products including vanadium-based catalysts, vanadium dioxide, energy storage materials and many other high value-added vanadium products.

[0057] The experimental results show that the present invention successfully prepares solid vanadium oxalate product under room temperature conditions, and the yield is above 95% and the purity is above 98%, thus ensuring a better preparation effect.

[0058] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0059] Example 1

[0060] A) Submillimeter powdered vanadium pentoxide (particle size distribution: 0.01-0.5 mm, average particle size: 0.05 mm) and oxalic acid are mixed in a molar ratio of 1:3.0, and water accounting for 10% of the total mass of the above raw materials is added, and stirred to form a wet powder.

[0061] B) The wet powder was kept at room temperature for 24 hours, then scraped to a thickness of 1 cm, air-dried at room temperature for 1 day, and crushed to obtain a blue solid vanadium oxalate product (specifically VOC 2 O 4 ·5H 2 O).

[0062] Among them, the XRD spectrum of the raw material vanadium pentoxide is as follows Figure 1 As shown, the XRD pattern of raw material oxalic acid is as follows Figure 2 As shown, the XRD spectrum of the solid vanadium oxalate product is as follows Figure 3 As shown, it can be seen that the present invention successfully produces vanadium oxalate product with a yield of 95% and a purity of 98%.

[0063] Example 2

[0064] A) Submillimeter powdered vanadium pentoxide (particle size distribution: 0.01-0.5 mm, average particle size: 0.05 mm) and oxalic acid are mixed in a molar ratio of 1:3.0, and water accounting for 20% of the total mass of the above raw materials is added, and stirred to form a wet powder.

[0065] B) The wet powder was kept at room temperature for 12 hours, then the material was scraped to a thickness of 2 cm and air-dried at room temperature for 2 days, and then ground to obtain a blue solid vanadium oxalate product (specifically VOC 2 O 4 ·5H 2 O).

[0066] The XRD spectrum of the solid vanadium oxalate product is as follows: Figure 4 As shown, it can be seen that the present invention successfully produces vanadium oxalate product with a yield of 99% and a purity of 99.5%.

[0067] Example 3

[0068] A) Submillimeter powdered vanadium pentoxide (particle size distribution: 0.01-0.5 mm, average particle size: 0.1 mm) and oxalic acid are mixed in a molar ratio of 1:3.0, and water accounting for 30% of the total mass of the above raw materials is added, and stirred to form a wet powder.

[0069] B) The wet powder was kept at room temperature for 8 hours, and then the material was scraped flat to a thickness of 2 cm and air-dried at room temperature for 2 days to obtain a blue solid vanadium oxalate product (specifically VOC 2 O 4 ·5H 2 O). The yield is 99% and the purity is 99%.

[0070] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A room temperature preparation method of vanadyl oxalate, characterized in that: include: A) mixing submillimeter powdered vanadium pentoxide, oxalic acid and water, and stirring to obtain a mixture; in, The sub-millimeter powdered vanadium pentoxide has a particle size distribution of 0.01 to 0.5 mm and an average particle size of 0.02 to 0.2 mm; B) keeping the mixture at room temperature for 32 to 84 hours to obtain a solid vanadyl oxalate product.

2. The preparation method according to claim 1, characterized in that: In step A), the molar ratio of vanadium pentoxide to oxalic acid is 1:(2.8-3.2).

3. The preparation method according to claim 1 or 2, characterized in that: In step A), the molar ratio of vanadium pentoxide to oxalic acid is 1:3.

0.

4. The preparation method according to claim 1, characterized in that: In step A), the amount of water used is 5% to 20% of the total mass of the vanadium pentoxide and oxalic acid.

5. The preparation method according to claim 1, characterized in that: Step B) specifically includes: The mixture is kept at room temperature for 8 to 36 hours, the material is scraped flat to a thickness of 1 to 2 cm and then air-dried at room temperature for 1 to 2 days to obtain a solid vanadyl oxalate product.

6. The preparation method according to claim 1, characterized in that: Step B) specifically comprises: scraping the mixture discharge to a thickness of 1 to 2 cm and air-drying at room temperature for 32 to 84 hours to obtain a solid vanadyl oxalate product.

7. The preparation method according to claim 1, characterized in that: In step B), after the mixture is kept at room temperature for 32 to 84 hours, the method further comprises: crushing or grinding.

8. The preparation method according to claim 1, characterized in that: In step A), the stirring speed is 10 to 60 rpm and the stirring time is 5 to 20 min.

9. The preparation method according to claim 1, characterized in that: The container used in step B) is a static container, or a stirring or drum reactor.

10. The preparation method according to claim 1, characterized in that: The container material / lining used in step B) is plastic, enamel, ceramic or corrosion-resistant metal.

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