Method for synthesizing zirconium silicate ceramic by using mineralizer to assist solid phase sintering

Abstract

The invention discloses a method for synthesizing zirconium silicate ceramic by using mineralizer assisted solid phase sintering, relates to the technical field of ceramic manufacturing, and aims to solve the problem of developing a novel and efficient mineralizer system. The preparation method comprises the following specific steps: S1, mixing nanoscale zirconium dioxide, silicon dioxide, a mineralizing agent and a grinding solvent in an agate mortar, and pressing to obtain a rough blank; and S2, heating the rough blank to 900-1500 DEG C at a speed of 5 DEG C / min in a muffle furnace, and sintering for 6 hours to obtain the ZrSiO4 ceramic body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic manufacturing, and particularly relates to a method for synthesizing zirconium silicate ceramic by using a mineralizer to assist solid-phase sintering. BACKGROUND

[0002] Zircon (ZrSiO4) is widely used in high-grade refractory materials, ceramic pigments, structural ceramics and nuclear waste immobilization due to its high melting point, low thermal expansion system, excellent chemical stability and corrosion resistance. Traditionally, the synthesis of ZrSiO4 mainly relies on the purification of natural zircon sand, but the resources of high-quality natural zircon sand are increasingly scarce, and its composition fluctuates greatly, which is difficult to meet the stringent requirements of high-end applications on material purity and uniformity. Therefore, it has become an important development direction in this field to prepare high-purity and performance-controllable ZrSiO4 powder by chemical synthesis method.

[0003] At present, the solid-phase reaction method using zirconia and silica as raw materials is the main way to synthesize zircon in the laboratory and industry. However, there is a core technical bottleneck in this synthesis process. Because the Zr-O bond and the Si-O bond have very high bond energy, the solid-phase reaction kinetics between zirconia and silica is extremely slow, and the reaction is incomplete. In order to achieve the full generation of ZrSiO4, very high synthesis temperature (usually higher than 1500℃) and long holding time are usually required. Such harsh process conditions not only result in huge energy consumption and high production cost, but also easily cause abnormal growth of powder particles and serious sintering, forming hard agglomeration, which seriously deteriorates the sintering activity of the final powder, the wide particle size distribution, and the microstructure and macroscopic performance of the subsequent products. In order to overcome the above problems, the introduction of mineralizers in the solid-phase reaction has become a key and effective technical strategy. The mineralizer can significantly enhance the diffusion and migration ability of ions by forming a liquid phase at high temperature or by intermediate compounds in the process, thereby effectively reducing the synthesis temperature and time of ZrSiO4 and accelerating the reaction process.

[0004] By selecting the appropriate type of mineralizer and optimizing its addition amount, ZrSiO4 powder with pure phase composition, regular crystal morphology and uniform particle size distribution can be obtained while significantly reducing the synthesis temperature and shortening the reaction time. Therefore, the development of new and efficient mineralizer systems and their application processes is of great industrial significance and commercial value for the low-temperature, energy-saving and low-cost preparation of high-performance synthetic zircon. SUMMARY

[0005] The present application aims to solve the problem of developing new and efficient mineralizer systems, and proposes a method for synthesizing zirconium silicate ceramic by using a mineralizer to assist solid-phase sintering, which includes the following specific steps: S1: Nano-sized zirconium dioxide, silicon dioxide, mineralizing agent and grinding solvent are mixed in an agate mortar and pressed to obtain a rough blank; S2: The rough blank is sintered in a muffle furnace at 5℃ / min to 900-1500℃ for 6h to obtain ZrSiO4 ceramic body.

[0006] A further provision of the present invention is that the mineralizing agent is any one of calcium fluoride, manganese oxide, manganese fluoride, copper oxide, and magnesium fluoride.

[0007] A further setting of the present invention is that the mass percentage of the mineralizing agent is 0.1-25 wt%.

[0008] A further feature of the present invention is that the particle size of the nano-sized zirconium dioxide powder is <50nm.

[0009] A further provision of the present invention is that the grinding solvent is anhydrous ethanol.

[0010] A further setting of the present invention is that the pressing pressure is 20 MPa and the time is 6 min.

[0011] A further provision of the present invention is that the sintering process is carried out in an air environment.

[0012] The beneficial effects of this invention are: by adding mineralizers, the sintering temperature can be reduced to 1000℃ and the sintering time can be reduced to 6h, which greatly improves the production efficiency of ZrSiO4 ceramic bodies and reduces energy consumption. Attached Figure Description

[0013] Figure 1 The XRM spectra of the products from Examples 2-8 with different amounts of magnesium fluoride added and sintered at 1000°C for 6 hours are shown.

[0014] Figure 2 The XRM spectra of the products sintered at different temperatures for 6 hours in Examples 2, 9-14 are shown. Detailed Implementation

[0015] Those skilled in the art can refer to the content of this document and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.

[0016] Example 1

[0017] This invention proposes a method for solid-phase sintering to form zirconium silicate ceramics using a mineralizer-assisted method, comprising the following specific steps:

[0018] S1: Nano-sized zirconium dioxide, silicon dioxide, mineralizing agent and grinding solvent are mixed in an agate mortar and pressed to obtain a rough blank.

[0019] S2: The rough blank is sintered in a muffle furnace at 5℃ / min to 900-1500℃ for 6 hours to obtain the ceramic body.

[0020] The mineralizing agent is any one of calcium fluoride, manganese oxide, manganese fluoride, copper oxide, and magnesium fluoride.

[0021] The mineralizer has a mass percentage of 0.1-25 wt% based on the total mass of nano-sized zirconium dioxide, silica, and mineralizer.

[0022] The particle size of nano-sized zirconium dioxide powder is <50nm.

[0023] The grinding solvent is anhydrous ethanol.

[0024] The pressing pressure is 20 MPa, and the time is 6 minutes.

[0025] The sintering process is carried out in an air environment.

[0026] Example 2

[0027] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0028] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 0.027g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 0.3wt%.

[0029] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0030] Example 3

[0031] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0032] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 0.092g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 1wt%.

[0033] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0034] Example 4

[0035] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0036] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 0.283g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 3wt%.

[0037] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0038] Example 5

[0039] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0040] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 0.482g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 5wt%.

[0041] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0042] Example 6

[0043] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0044] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 1.017g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 10wt%.

[0045] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0046] Example 7

[0047] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0048] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 1.670g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 15wt%.

[0049] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0050] Example 8

[0051] This embodiment prepares zirconium silicate ceramics according to the method disclosed in Example 1, specifically including the following steps:

[0052] S1: 6.16g of nano-sized zirconium dioxide, 3g of silicon dioxide, 2.290g of magnesium fluoride, and grinding solvent were mixed in an agate mortar and pressed at 20MPa to obtain a rough blank. That is, the mass percentage of magnesium fluoride was 20wt%.

[0053] S2: The dried blank is sintered in a muffle furnace at 5℃ / min to 1000℃ for 6 hours to obtain ZrSiO4 ceramic body.

[0054] Example 9

[0055] The only difference between this embodiment and Embodiment 2 is that the temperature is raised to 900°C and sintered for 6 hours. All other conditions are the same.

[0056] Example 10

[0057] The only difference between this embodiment and Embodiment 2 is that the temperature is raised to 1100℃ and sintered for 6 hours. All other conditions are the same.

[0058] Example 11

[0059] The only difference between this embodiment and Embodiment 2 is that the temperature is raised to 1200℃ and sintered for 6 hours. All other conditions are the same.

[0060] Example 13

[0061] The only difference between this embodiment and Embodiment 2 is that the temperature is raised to 1400℃ and sintered for 6 hours. All other conditions are the same.

[0062] Example 14

[0063] The only difference between this embodiment and Embodiment 2 is that the temperature is raised to 1500℃ and sintered for 6 hours. All other conditions are the same.

[0064] This invention significantly reduces the synthesis temperature and time of ZrSiO4 ceramics by introducing magnesium fluoride as a mineralizing agent, combined with... Figure 1 , 2 It can be seen that the ZrSiO4 ceramic body synthesized at 1000℃ with the addition of 15wt% mineralizer has higher purity and better crystallinity, providing a new route for the large-scale industrial application of ZrSiO4 ceramic body prepared by solid-state sintering.

[0065] In summary, by adding a mineralizer, this invention can reduce the sintering temperature to 1000℃ and the sintering time to 6 hours, which greatly improves the production efficiency of ZrSiO4 ceramic bodies and reduces energy consumption.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be within the scope of protection of the present invention.

Claims

1. A method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer, characterized in that, The specific steps include the following: S1: Nano-sized zirconium dioxide, silicon dioxide, mineralizing agent and grinding solvent are mixed in an agate mortar and pressed to obtain a rough blank; S2: The rough blank is sintered in a muffle furnace at 5℃ / min to 900-1500℃ for 6h to obtain ZrSiO4 ceramic body.

2. The method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer according to claim 1, characterized in that, The mineralizing agent is any one of calcium fluoride, manganese oxide, manganese fluoride, copper oxide, and magnesium fluoride.

3. The method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer according to claim 1, characterized in that, The mineralizer has a mass percentage of 0.1-25 wt%.

4. The method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer according to claim 1, characterized in that, The particle size of the nano-sized zirconium dioxide powder is <50nm.

5. The method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer according to claim 1, characterized in that, The grinding solvent is anhydrous ethanol.

6. The method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer according to claim 1, characterized in that, The pressing pressure is 20 MPa, and the time is 6 minutes.

7. The method for forming zirconium silicate ceramics by solid-phase sintering assisted by a mineralizer according to claim 1, characterized in that, The sintering process is carried out in an air environment.

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