Preparation method of zirconium molybdate

Abstract

The invention discloses a preparation method of zirconium molybdate particles, and belongs to the technical field of inorganic functional materials. In the preparation process, zirconium nitrate pentahydrate and ammonium molybdate tetrahydrate are used as raw materials, and deionized water is used as a solvent. The preparation method comprises the following steps: respectively dissolving the two raw materials in water, mixing, washing a reaction white gel product with water, washing with alcohol, centrifuging, drying, grinding and screening to obtain a precursor, roasting and recrystallizing to obtain zirconium molybdate particles, and controlling the particle size of the particles by the screening mesh number. The method has the advantages of few types of raw materials, simple preparation process and controllable particle size, and is beneficial to large-scale production and material performance optimization of zirconium molybdate.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic functional materials, and particularly relates to a method for preparing zirconium molybdate. Background Art

[0002] Transition metal molybdates are a class of inorganic compounds with diverse applications. Molybdates can be used as catalysts, exhibiting particularly good catalytic performance in redox reactions. When combined with organic pigments, they can produce a remarkably bright sheen, high hue, and strong hiding power, making them suitable for high-end coatings requiring excellent weather resistance. Zirconium molybdate, a key member of this class, exhibits broad application prospects, including in optical materials, chemical conversion coatings, and biological fluorescent markers. These applications demonstrate the diversity and importance of zirconium molybdate in industry and scientific research, necessitating the development of a simple, efficient, and size-controllable preparation method.

[0003] Currently, commonly used methods for preparing molybdate materials include hydrothermal synthesis, ultrasonic synthesis, microwave radiation, and solid-phase synthesis. Chinese patent CN115611312B discloses a method for preparing zirconium molybdate nanoparticles via a hydrothermal method, capable of producing zirconium molybdate particles with a particle size of 200-300 nm. However, the preparation requires numerous raw materials, the preparation method is complex, and there are numerous intermediate steps, resulting in a limited size range for the resulting zirconium molybdate particles. The present invention aims to develop zirconium molybdate particles with simple raw materials, a simple preparation process, and controllable particle size. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing zirconium molybdate.

[0007] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing zirconium molybdate, characterized in that: it comprises:

[0008] mixing zirconium nitrate pentahydrate with deionized water to obtain a zirconium nitrate pentahydrate solution, and mixing ammonium molybdate tetrahydrate with deionized water to obtain an ammonium molybdate tetrahydrate solution;

[0009] The ammonium molybdate tetrahydrate solution and the zirconium nitrate pentahydrate solution are mixed, allowed to stand, and then washed with water, washed with alcohol, centrifuged, dried, ground, and sieved to obtain a precursor;

[0010] The precursor is heated, cooled in the furnace, and then taken out and air-cooled to obtain the zirconium molybdate particles.

[0011] As a preferred embodiment of the preparation method of the present invention, the concentration of the zirconium nitrate pentahydrate solution is 0.1 to 1.5 mol / L.

[0012] As a preferred embodiment of the preparation method of the present invention, the concentration of the ammonium molybdate tetrahydrate solution is 0.01 to 0.3 mol / L.

[0013] As a preferred embodiment of the preparation method of the present invention, wherein: Zr4+ in the zirconium nitrate pentahydrate solution and (MoO4) in the ammonium molybdate tetrahydrate solution 2- The molar ratio is 0.1 to 10.

[0014] As a preferred embodiment of the preparation method of the present invention, the centrifugal speed is 3500-5000 r / min.

[0015] As a preferred embodiment of the preparation method of the present invention, the centrifugation time is 0.5 to 2 hours.

[0016] As a preferred embodiment of the preparation method of the present invention, the drying temperature is 60-90°C.

[0017] As a preferred embodiment of the preparation method of the present invention, the drying time is 15 to 30 hours.

[0018] As a preferred embodiment of the preparation method of the present invention, the mesh size of the sieving is 70-500 mesh.

[0019] As a preferred embodiment of the preparation method of the present invention, the precursor is heated, then cooled in the furnace and then taken out for air cooling, wherein the heating temperature is 400-900°C, the heating rate is 4-6°C / min, and the holding time is 100-200min.

[0020] Beneficial effects of the present invention:

[0021] The present invention has few types of raw materials and a simple preparation method. Only two reaction raw materials, zirconium nitrate pentahydrate and ammonium molybdate tetrahydrate, are used, and the solvent deionized water raw material is easy to obtain, and no auxiliary reagents such as crystallization templates are required. The subsequent steps of cleaning, centrifugation, drying, grinding, and roasting are easy to implement in engineering, which is conducive to large-scale production; and the particle size of the obtained zirconium molybdate particles is controllable. The raw materials zirconium nitrate pentahydrate and ammonium molybdate tetrahydrate are both easily soluble in water. Even if they are not completely reacted and remain in the mixed solution, they can be easily removed by the water washing step, and the reaction product has high purity. The zirconium molybdate precursor after drying is in block form and needs to be ground into a smaller size and sieved to ensure that the precursor reacts uniformly during the roasting process. By selecting sieves with different mesh sizes, the size of the precursor can be accurately controlled, and the recrystallization process will not change the volume of the precursor. Therefore, the size of the prepared zirconium molybdate particles can be regulated to broaden the application range of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0023] Figure 1 This is the XRD pattern of the zirconium molybdate particles prepared in Example 1 of the present invention.

[0024] Figure 2 This is the XRD pattern of the zirconium molybdate particles prepared in Example 2 of the present invention.

[0025] Figure 3 This is the XRD pattern of the zirconium molybdate particles prepared in Example 3 of the present invention.

[0026] Figure 4 This is a real picture of the zirconium molybdate particles prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0030] Unless otherwise specified, all raw materials used in the examples of the present invention are commercially available. Details are shown in Table 1.

[0031] Table 1

[0032] name Commercial channels Item No. Zirconium nitrate pentahydrate Maclean Z822551 Ammonium molybdate tetrahydrate Maclean A915065

[0033] Example 1

[0034] This embodiment provides a method for preparing zirconium molybdate particles:

[0035] (1) Prepare zirconium nitrate solution with a molar concentration of 0.15 mol / L and ammonium molybdate solution with a molar concentration of 0.043 mol / L at room temperature. 4+ and ammonium molybdate solution (MoO4) 2- The molar ratio is 1:2.

[0036] (2) Slowly add the ammonium molybdate solution to the continuously stirred zirconium nitrate solution, and continue stirring for 10 minutes after the addition is completed to ensure sufficient reaction to obtain a white gel product.

[0037] (3) The white gel product was washed twice with water and once with alcohol, and then centrifuged at 3500 r / min for 90 minutes. The lower white precipitate was vacuum dried at 80°C for 16 hours, maintaining a high vacuum in the chamber.

[0038] (4) The dried white block product needs to be ground and sieved using a 200-mesh sieve to obtain a precursor.

[0039] (5) The precursor was placed in a muffle furnace and calcined at a temperature of 650°C, a heating rate of 6°C / min, and a holding time of 120 minutes. The precursor was cooled to 200°C in the furnace and then taken out for air cooling.

[0040] Figure 1 The XRD results showed that the product was zirconium molybdate (Zr(MoO4) 2 ) crystals, and no spots were observed in the diffraction peaks, indicating that the precursor was completely transformed into zirconium molybdate crystals. Figure 4 This is a real picture of the zirconium molybdate particles prepared in Example 1 of the present invention.

[0041] Example 2

[0042] This embodiment provides a method for preparing zirconium molybdate particles:

[0043] (1) Prepare zirconium nitrate solution with a molar concentration of 0.6 mol / L and ammonium molybdate solution with a molar concentration of 0.17 mol / L at room temperature. 4+ and ammonium molybdate solution (MoO4) 2- The molar ratio is 1:2.

[0044] (2) Slowly add the ammonium molybdate solution to the continuously stirred zirconium nitrate solution, and continue stirring for 20 minutes after the addition is completed to ensure sufficient reaction to obtain a white gel product.

[0045] (3) The white gel product was washed twice with water and once with alcohol, and then centrifuged at 4500 r / min for 120 minutes. The lower white precipitate was vacuum dried at 80°C for 30 hours, maintaining a high vacuum in the chamber.

[0046] (4) The dried white block product needs to be ground and sieved using a 400-mesh sieve to obtain a precursor.

[0047] (5) The precursor was placed in a muffle furnace and calcined at a temperature of 400°C, a heating rate of 6°C / min, and a holding time of 120 minutes. After cooling to 200°C in the furnace, the precursor was taken out and air-cooled.

[0048] Figure 2 It is shown that due to the low calcination temperature, the obtained product does not show crystalline properties, indicating that the precursor has not reacted to transform into zirconium molybdate.

[0049] Example 3

[0050] This embodiment provides a method for preparing zirconium molybdate particles:

[0051] (1) Prepare zirconium nitrate solution with a molar concentration of 0.2 mol / L and ammonium molybdate solution with a molar concentration of 0.057 mol / L at room temperature. 4+ and ammonium molybdate solution (MoO4) 2- The molar ratio is 1:2.

[0052] (2) Slowly add the ammonium molybdate solution to the continuously stirred zirconium nitrate solution, and continue stirring for 10 minutes after the addition is completed to ensure sufficient reaction to obtain a white gel product.

[0053] (3) The white gel product was washed twice with water and once with alcohol, and then centrifuged at 3500 r / min for 70 minutes. The lower white precipitate was vacuum dried at 80°C for 20 hours, maintaining a high vacuum in the chamber.

[0054] (4) The dried white block product needs to be ground and sieved using a 300-mesh sieve to obtain a precursor.

[0055] (5) The precursor was placed in a muffle furnace and calcined at a temperature of 800°C, a heating rate of 10°C / min, and a holding time of 120 minutes. After cooling to 200°C in the furnace, the precursor was taken out and air-cooled.

[0056] Figure 3 The main reaction product is zirconium molybdate (Zr(MoO4)2) crystals, but due to the high reaction temperature, a small amount of zirconium molybdate further decomposes to form zirconium oxide (ZrO2). The product is composed of zirconium molybdate (95.1%) and zirconium oxide (4.9%), resulting in a low purity.

[0057] Example 4

[0058] The difference from Example 1 is that the centrifugal speed in step (3) is set to 4000 r / min, the centrifugal time is 60 minutes, the drying temperature is 80°C, and the drying time is 20 hours; the sintering temperature in step (5) is 650°C, the heating rate is 4°C / min, and the holding time is 30 minutes. The other steps are consistent with Example 1.

[0059] Due to the short reaction time, the precursor did not react fully and was only partially converted into zirconium molybdate crystals, with the proportion of the precursor that reacted being 73%.

[0060] Example 5

[0061] The difference from Example 1 is that the centrifugal speed in step (3) is set to 5000 r / min, the centrifugal time is 40 minutes, the drying temperature is 90°C, and the drying time is 15 hours; the sintering temperature in step (5) is 850°C, the heating rate is 6°C / min, and the holding time is 50 minutes. The other steps are consistent with Example 1.

[0062] The reaction product consists of zirconium molybdate and zirconium oxide, of which zirconium molybdate accounts for 80.5% and zirconium oxide accounts for 19.5%.

[0063] Comparative Example 1

[0064] The difference from Example 1 is that in step (1), a zirconium nitrate solution with a molar concentration of 0.3 mol / L and an ammonium molybdate solution with a molar concentration of 0.043 mol / L are prepared at room temperature, and the zirconium nitrate solution participating in the reaction contains Zr 4+and ammonium molybdate solution (MoO4) 2- The molar ratio of is 1:1, and the other steps are consistent with Example 1.

[0065] The zirconium nitrate that did not participate in the reaction has been completely removed during the two water washing processes, and the precursor has high purity. The obtained product is zirconium molybdate (Zr(MoO4) 2 ) crystals, indicating that the precursor is completely transformed into zirconium molybdate crystals.

[0066] Comparative Example 2

[0067] The difference from Example 2 is that the centrifugal speed in step (3) is set to 5000 r / min and the centrifugation time is 120 minutes; in step (4), the dried white block product is ground and sieved using a 500-mesh screen to obtain a precursor; and in step (5), the sintering temperature is 650°C, the heating rate is 8°C / min, and the holding time is 100 minutes. The other steps are the same as in Example 2.

[0068] The obtained product is zirconium molybdate (Zr(MoO4) 2 ) crystals, indicating that the precursor is completely transformed into zirconium molybdate crystals.

[0069] Comparative Example 3

[0070] The difference from Example 3 is that in step (1), a zirconium nitrate solution with a molar concentration of 0.2 mol / L and an ammonium molybdate solution with a molar concentration of 0.057 mol / L are prepared at room temperature, and the zirconium nitrate solution participating in the reaction contains Zr 4+ and ammonium molybdate solution (MoO4) 2- The molar ratio of the precursor is 1:4; Step (4) is sieved using a 500-mesh sieve to obtain a precursor. The other steps are the same as those in Example 3.

[0071] The unreacted ammonium molybdate was completely removed during the two water washes. The resulting product contains no ammonium molybdate. Due to the high sintering temperature, the product is a mixture of zirconium molybdate and zirconium oxide, with zirconium molybdate accounting for 94.3% and zirconium oxide accounting for 5.7%.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the present invention.

Claims

1. A method for preparing zirconium molybdate, characterized in that: include, mixing zirconium nitrate pentahydrate with deionized water to obtain a zirconium nitrate pentahydrate solution, and mixing ammonium molybdate tetrahydrate with deionized water to obtain an ammonium molybdate tetrahydrate solution; The ammonium molybdate tetrahydrate solution and the zirconium nitrate pentahydrate solution are mixed, allowed to stand, and then washed with water, washed with alcohol, centrifuged, dried, ground, and sieved to obtain a precursor; The precursor is heated, cooled in the furnace, and then taken out and air-cooled to obtain the zirconium molybdate particles.

2. The preparation method according to claim 1, wherein: The concentration of the zirconium nitrate pentahydrate solution is 0.1-1.5 mol / L.

3. The preparation method according to claim 1, wherein: The concentration of the ammonium molybdate tetrahydrate solution is 0.01-0.3 mol / L.

4. The preparation method according to claim 3 or 4, wherein: The Zr in the zirconium nitrate pentahydrate solution 4+ With (MoO4) in ammonium molybdate tetrahydrate solution 2- The molar ratio is 0.1 to 10.

5. The preparation method according to claim 4, wherein: The centrifugal speed is 3500-5000 r / min.

6. The preparation method according to claim 5, wherein: The centrifugation time is 0.5 to 2 hours.

7. The preparation method according to claim 1, wherein: The drying temperature is 60-90°C.

8. The preparation method according to claim 7, wherein: The drying time is 15 to 30 hours.

9. The preparation method according to claim 1, wherein: The mesh number of the screening is 70-500 mesh.

10. The preparation method according to claim 1, wherein: The precursor is heated, cooled in the furnace, and then taken out for air cooling, wherein the heating temperature is 400-900° C., the heating rate is 4-6° C. / min, and the holding time is 100-200 min.

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