A release agent for vitrification of radioactive nuclear waste using white glass microspheres and its preparation.

Abstract

This invention belongs to the field of glass microsphere preparation technology, and provides a release agent for fire polishing of white glass microspheres used in the vitrification of radioactive nuclear waste, and its preparation method. The release agent comprises the following components by mass fraction: 10-70% alumina powder, 20-90% quartz sand, 1-3% cerium oxide powder, and 1-6% white flour. By introducing white flour, the release agent of this invention can both protect the color of the white beads themselves and prevent the formation of twins or triplets during the fire polishing process. It also prevents the introduction of major chemical elements into the surface of the glass beads during the release process, thus increasing the compositional stability of the glass beads.

Description

Technical Field

[0001] This invention relates to the field of glass microsphere preparation technology, and in particular to a release agent for fire polishing of white glass microspheres used for glass curing of radioactive nuclear waste, and its preparation. Background Technology

[0002] Glass beads are prepared through processes such as mold pressing, crushing, fire polishing, and cleaning and drying. During fire polishing, a release agent is used to separate the glass bead blanks to prevent the glass beads from sticking together in the fire polishing tube and to prevent the glass beads from sticking together.

[0003] Carbon can increase the smoothness between glass beads at high temperatures, and existing technologies generally increase this smoothness by introducing graphite into the release agent. However, the introduction of graphite often makes the surface of white glass beads appear dark.

[0004] Chinese Patent CN114014529A discloses a release agent for fire blasting of borosilicate glass beads. The release agent is composed of the following components by mass percentage: 10-60% alumina powder, 30-80% quartz sand, 3-0.5% salt, 1-3% cerium oxide powder, and 1-3% magnesium oxide powder. This release agent ensures that no impurities are introduced into the glass beads during high-temperature contact between the borosilicate glass bead blank and the release agent in the actual fire blasting process, thus ensuring that the composition of the finished borosilicate glass beads meets the required specifications. Although it describes how designing the particle size distribution of the release agent raw materials and adjusting it to an appropriate angle of repose ensures good flowability of the release agent during use, reducing the possibility of glass beads sticking together in the fire blasting furnace drum and improving the efficiency of fire blasting, the glass beads prepared using the above release agent still exhibit issues such as large glass beads and small glass beads sticking together, forming twins or triplets. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a release agent for fire blasting of white glass microspheres used in the vitrification of radioactive nuclear waste, and its preparation method. The release agent for fire blasting of white glass microspheres used in the vitrification of radioactive nuclear waste provided by this invention can further reduce the occurrence of twins and triplets in the glass beads.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a release agent for the fire polishing of white glass microspheres used in the vitrification of radioactive nuclear waste, comprising the following components by mass fraction:

[0008] Alumina powder 10-70%, quartz sand 20-90%, cerium oxide powder 1-3%, wheat flour 1-6%.

[0009] Preferably, the water content of the release agent is less than 1%.

[0010] This invention also provides a method for preparing the release agent for the fire polishing of white glass microspheres used for vitrification of radioactive nuclear waste as described in the above technical solution, comprising the following steps:

[0011] Alumina powder, quartz sand, cerium oxide powder and wheat flour are mixed and ground to obtain fine powder.

[0012] The fine powder is baked to obtain the release agent for the fire polishing of white glass microspheres used for the glass curing of radioactive nuclear waste.

[0013] Preferably, the alumina powder has a particle size of 140-200 mesh.

[0014] Preferably, the particle size of the quartz sand is 40 to 140 mesh.

[0015] Preferably, the cerium oxide powder has a particle size of 180-220 mesh.

[0016] Preferably, the particle size of the white flour is 325 mesh.

[0017] Preferably, the baking temperature is 80–120°C.

[0018] Preferably, after baking, the material is further subjected to ball milling; the particle size of the material obtained by ball milling is less than 200 mesh.

[0019] This invention provides a release agent for the fire polishing of white glass microspheres used for the glass curing of radioactive nuclear waste, comprising the following components by mass fraction: 10-70% alumina powder, 20-90% quartz sand, 1-3% cerium oxide powder, and 1-6% wheat flour.

[0020] The release agent of this invention, by introducing white flour, can both protect the color of the white beads themselves and allow the glass bead blanks to be fully separated, thereby avoiding adhesion and reducing the occurrence of twins, triplets, and other fire-polished glass bead products during the fire polishing process. In addition, it avoids the introduction of the main chemical elements in the release agent to the surface of the glass bead products, thus increasing the compositional stability of the glass bead products. Attached Figure Description

[0021] Figure 1 A photograph of a glass bead obtained using the release agent obtained in Example 1. Detailed Implementation

[0022] This invention provides a release agent for the fire polishing of white glass microspheres used in the vitrification of radioactive nuclear waste, comprising the following components by mass fraction:

[0023] Alumina powder 10-70%, quartz sand 20-90%, cerium oxide powder 1-3%, wheat flour 1-6%.

[0024] Unless otherwise specified, all raw materials used in this invention are preferably commercially available products.

[0025] The release agent for the fire polishing of white glass microspheres for the glass curing of radioactive nuclear waste provided by the present invention comprises 10-70% alumina powder by mass, preferably 15-50%, and more preferably 30-40%.

[0026] The release agent for the fire polishing of white glass microspheres for the vitrification of radioactive nuclear waste provided by the present invention comprises 20-90% by mass of quartz sand, preferably 21-86%, and more preferably 70-80%.

[0027] The release agent for the fire polishing of white glass microspheres for the glass curing of radioactive nuclear waste provided by the present invention comprises 1-3% cerium oxide powder by mass, preferably 1.5-2.5%, and more preferably 2%.

[0028] The release agent for fire polishing of white glass microspheres used for glass curing of radioactive nuclear waste provided by the present invention comprises 1-6% by mass of white flour, preferably 2-5%, and more preferably 3-4%. In the present invention, the white flour is preferably ordinary white flour.

[0029] In this invention, the water content of the separating agent is preferably less than 1%, and more preferably 0.5%.

[0030] In this invention, the particle size of the separating agent is preferably less than 200 mesh.

[0031] This invention also provides a method for preparing the release agent for the fire polishing of white glass microspheres used for vitrification of radioactive nuclear waste as described in the above technical solution, comprising the following steps:

[0032] Alumina powder, quartz sand, cerium oxide powder and wheat flour are mixed and ground to obtain fine powder.

[0033] The fine powder is baked to obtain the release agent for the fire polishing of white glass microspheres used for the glass curing of radioactive nuclear waste.

[0034] This invention involves mixing alumina powder, quartz sand, cerium oxide powder, and wheat flour, then grinding them to obtain a fine powder.

[0035] In this invention, the particle size of the alumina powder is preferably 140-200 mesh. In this invention, the particle size of the quartz sand is preferably 40-140 mesh. In this invention, the particle size of the cerium oxide powder is preferably 180-220 mesh. In this invention, the particle size of the wheat flour is preferably 325 mesh.

[0036] This invention does not specifically limit the grinding parameters, as long as the material is ground until there are no obvious particles. In a specific embodiment of this invention, the grinding is preferably performed three times.

[0037] After obtaining the fine powder, the present invention bakes the fine powder to obtain the release agent for the fire polishing of white glass microspheres for the glass curing of radioactive nuclear waste.

[0038] In this invention, the baking temperature is preferably 80–120°C. This invention does not specifically limit the baking time, as long as the moisture content of the baked material is less than 1%.

[0039] After baking, the present invention preferably further includes ball milling. The present invention does not specifically limit the parameters of the ball milling, as long as the particle size of the material obtained by ball milling is below 200 mesh.

[0040] The following detailed description, in conjunction with embodiments, illustrates the release agent for the fire polishing of white glass microspheres used for the glass curing of radioactive nuclear waste provided by the present invention and its preparation thereof. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0041] Example 1

[0042] The release agent mix is ​​prepared by mixing 70% alumina powder (140-200 mesh), 21% quartz sand (40-140 mesh), 3% cerium oxide powder (180-220 mesh), and 6% wheat flour (325 mesh).

[0043] Mix and stir the release agent compound, sieve it three times and grind it until no obvious particles are present.

[0044] The ground mixture was baked at 80°C for 60 minutes, and then the release agent was ground in a ball mill to a mesh size of less than 200 to obtain the release agent.

[0045] Measure the water content in the release agent and ensure that the water content is less than 1%. If the requirement is not met, dry the prepared mixture for 30 minutes to meet the water content requirement.

[0046] By measuring the composition of the glass bead product prepared using the release agent obtained in Example 1, it was found that the elemental composition of the glass bead product before and after fire polishing was almost unchanged, and the main components of the glass bead product, SiO2 and Al2O3, showed no significant fluctuation.

[0047] Example 2

[0048] The release agent mix is ​​prepared by mixing 10% alumina powder (140-200 mesh), 86% quartz sand (40-140 mesh), 3% cerium oxide powder (180-220 mesh), and 1% wheat flour (325 mesh).

[0049] Mix and stir the release agent compound, sieve it three times and grind it until no obvious particles are present.

[0050] The ground mixture was baked at 120°C for 60 minutes, and then the release agent was ground in a ball mill to below 200 mesh to obtain the release agent.

[0051] Measure the water content in the release agent and ensure that the water content is less than 1%. If the requirement is not met, dry the prepared mixture for 30 minutes to meet the water content requirement.

[0052] Example 3

[0053] The release agent mix is ​​prepared by mixing 15% alumina powder (140-200 mesh), 80% quartz sand (40-140 mesh), 2% cerium oxide powder (180-220 mesh), and 3% wheat flour (325 mesh).

[0054] Mix and stir the release agent compound, sieve it three times and grind it until no obvious particles are present.

[0055] The ground mixture was baked at 100℃ for 60 minutes, and then the release agent was ground in a ball mill to below 200 mesh to obtain the release agent.

[0056] Measure the water content in the release agent and ensure that the water content is less than 1%. If the requirement is not met, dry the prepared mixture for 30 minutes to meet the water content requirement.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that white flour is replaced with graphite powder.

[0059] Replacing the white flour in the release agent of Example 1 with graphite powder, which is also composed of carbon, revealed the following: Before flame polishing, the glass beads were white; after flame polishing, and following washing and drying, the glass beads obtained using the release agent with added graphite powder had a darker surface. In contrast, the glass beads obtained using the release agent with added white flour had a smooth and transparent surface. Figure 1 As shown.

[0060] Comparative Example 2

[0061] A release agent for fire polishing borosilicate glass beads, the release agent comprising the following components by mass percentage: 40% alumina powder (140 mesh), 55% quartz sand (90 mesh), 3% industrial grade salt, 1% cerium oxide powder (200 mesh), and 1% magnesium oxide powder (200 mesh).

[0062] The method for preparing the release agent used in the fire polishing of borosilicate glass beads includes:

[0063] (1) According to the formula of the release agent, weigh alumina powder, quartz sand, salt, cerium oxide powder and magnesium oxide powder to prepare the release agent mixture.

[0064] (2) Mix the release agent mixture and sieve it through a 30-mesh sieve.

[0065] (3) The release agent is dried so that its moisture content is less than 1% by mass.

[0066] The resulting release agent has a water content of less than 1% by mass and a powder rest angle of 30–45°.

[0067] Among them, the conductivity of the prepared release agent powder in aqueous solution was tested, and the change in conductivity after more than three random samplings reached more than 95%.

[0068] The release agents obtained in Examples 1-3 and Comparative Examples 1-2 were mixed with borosilicate glass bead blanks and sent into a fire blasting furnace for fire blasting treatment to obtain borosilicate glass beads.

[0069] Table 1 lists the presence of twins and triplets in the finished beads obtained with different release agents.

[0070] Table 1. Presence of twins and triplets in finished beads obtained with different release agents.

[0071] Twin content (wt%) Triplets content (wt%) Single fetus content (wt%) Example 1 0 0 100 Example 2 0.5 0.05 99.45 Example 3 0.3 0.02 99.68 Comparative Example 1 0 0 100 Comparative Example 2 2 1.5 96.5

[0072] As can be seen from Table 1, the number of twins and triplets in the glass beads prepared using the isolating agent product of the present invention is significantly reduced, and the final product yield is greater than 99%, while the product in the comparative example is dark in color and the yield is less than 98%.

[0073] 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 considered within the scope of protection of the present invention.

Claims

1. A release agent for white glass microbead fire polishing for radioactive nuclear waste glass solidification, characterized by, Composed of the following components by mass fraction: Alumina powder 10~70%, quartz sand 21~86%, cerium oxide powder 1~3%, white flour 1~6%; The preparation method of the isolating agent for the white glass microbead fire polishing for the radioactive nuclear waste glass solidification comprises the following steps: Mixing alumina powder, quartz sand, cerium oxide powder and white flour, grinding to obtain fine powder; Roasting the fine powder to obtain the isolating agent for the white glass microbead fire polishing for the radioactive nuclear waste glass solidification; The particle size of the alumina powder is 140~200 mesh; The particle size of the quartz sand is 40~140 mesh; The particle size of the cerium oxide powder is 180~220 mesh; The particle size of the white flour is 325 mesh; The roasting temperature is 80~120℃.

2. The sequestering agent of claim 1, wherein, The water content of the isolating agent is less than 1%.

3. The method for producing a release agent for the thermal polishing of white glass beads for the vitrification of radioactive waste according to any one of claims 1 to 2, characterized in that, Comprising the following steps: Mixing alumina powder, quartz sand, cerium oxide powder and white flour, grinding to obtain fine powder; Roasting the fine powder to obtain the isolating agent for the white glass microbead fire polishing for the radioactive nuclear waste glass solidification; The particle size of the alumina powder is 140~200 mesh; The particle size of the quartz sand is 40~140 mesh; The particle size of the cerium oxide powder is 180~220 mesh; The particle size of the white flour is 325 mesh; The roasting temperature is 80~120℃.

4. The production method according to claim 3, characterized by, After the roasting, it further comprises ball milling; the particle size of the material obtained by the ball milling is 200 mesh or less.

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