Adsorbent for chemical ruthenium removal as well as preparation method and application thereof

Abstract

The invention discloses an adsorbent for chemical ruthenium removal as well as a preparation method and application thereof, the preparation method comprises the following steps: S1, mixing yttrium sol with carrier microspheres, carrying out vacuum impregnation treatment to enable the carrier microspheres to adsorb the yttrium sol, and then filtering to obtain a complex; s2, drying the complex to obtain a dried body; and S3, calcining the dried body, and cooling to obtain the yttrium oxide-based adsorbent for chemical ruthenium removal. The adsorbent for chemical ruthenium removal is high in adsorption capacity and large in adsorption capacity, ruthenium tetroxide gas can be adsorbed and subjected to chemical reaction fixation, and the ruthenium removal effect is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear engineering, and particularly relates to an adsorbent for chemical ruthenium removal, a preparation method thereof, and an application thereof. Background Art

[0002] The treatment of spent fuel (i.e., nuclear fuel after being burned in a reactor) is a crucial link. Since spent fuel contains a large amount of radioactive substances and long-lived nuclides, such as uranium, plutonium, and ruthenium, etc. Among them, ruthenium, as an important fission product, has a relatively high content in spent fuel and has high radioactivity, posing a potential threat to the environment and human health.

[0003] In order to effectively remove ruthenium element (ruthenium tetroxide) from spent fuel, a ruthenium removal adsorbent is required to adsorb ruthenium through the ruthenium removal adsorbent, so as to achieve the purpose of ruthenium removal. For example, Patent CN1076543A discloses a method for trapping gaseous ruthenium on polyvinylpyridine, which uses an adsorbent containing an ethylene pyridine polymer or copolymer to adsorb ruthenium tetroxide gas. The ethylene pyridine-based adsorbent belongs to organic polymer materials and has defects such as poor high-temperature resistance (100 - 150 °C) and easy decomposition. In addition, some studies have found that CaO, CaCO3, SrCO3, BaCO3, Y2O3, and Nd2O3 all have different degrees of trapping

[0004] abilities for ruthenium tetroxide. However, alkaline earth metal compounds such as BaCO3 and SrCO3 have harmful effects on human health, and chemical methods using alkaline earth metal compounds will also cause problems such as partial blockage of the flow channel due to the flying out of fine powder; the product formed by the reaction of CaO and ruthenium tetroxide is CaRuO3, and its stability is relatively poor; while the product formed by the reaction of Y2O3 and ruthenium tetroxide is Y2Ru2O7, and its thermal stability is as high as 1400 °C, which is significantly better than that of CaO. However, the pure Y2O3 ruthenium removal adsorbent has deficiencies such as low adsorption capacity, and there is a large difference from the theoretical adsorption capacity. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an adsorbent for chemical ruthenium removal, a preparation method thereof, and an application thereof, aiming at the above deficiencies existing in the prior art. The adsorbent has strong adsorption ability and large adsorption capacity, can adsorb ruthenium tetroxide gas and carry out chemical reaction fixation, and has good ruthenium removal effect.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] According to the first aspect of the present invention, a preparation method of an adsorbent for chemical ruthenium removal is provided, including:

[0008] S1, mixing yttrium sol and carrier microspheres, performing vacuum impregnation treatment to enable the carrier microspheres to adsorb the yttrium sol, and then filtering to obtain a composite body;

[0009] S2. Dry the complex to obtain a dried product.

[0010] S3. Calcinate the dried product and cool it to obtain an adsorbent for chemical ruthenium removal based on yttrium oxide.

[0011] Preferably, the mixing mass ratio of the yttrium sol to the carrier microspheres is 3 - 4:1.

[0013] Preferably, the vacuum degree in the vacuum impregnation process is 0.1 - 0.15 Pa.

[0014] Preferably, the temperature of the drying treatment is 50 - 55 °C and the time is 2 - 3 h.

[0015] Preferably, the calcination treatment includes: first heating to 230 - 235 °C at a rate of 3 °C / min and holding for 30 - 40 min; then heating to 550 - 600 °C at a rate of 5 °C / min and holding for 1 - 1.5 h.

[0016] Preferably, the carrier microspheres are prepared according to the following steps:

[0017] Add methyl acrylate and deionized water to the reaction kettle in sequence and stir and mix.

[0018] Introduce a protective gas into the reaction kettle to discharge the air in the reaction kettle.

[0019] Add an initiator, then keep it warm in a water bath for a period of time, stir at a speed of 450 - 500 r / min for a period of time, and then cool to room temperature to obtain a mixture.

[0020] Centrifuge the mixture, collect the precipitate, wash and dry it to obtain the carrier microspheres.

[0021] Preferably, the mixing volume ratio of methyl acrylate to deionized water is 1:10 - 15.

[0023] Preferably, the initiator is potassium peroxide and its dosage is 5 - 6% of the mass of methyl acrylate.

[0024] Preferably, the drying temperature of the mixture is 55 - 60 °C.

[0025] Preferably, the yttrium sol is prepared according to the following steps:

[0026] Add yttrium nitrate to deionized water and stir and mix evenly to obtain a yttrium nitrate solution.

[0027] Add citric acid to the yttrium nitrate solution, adjust the temperature to 30 - 35 °C, and stir evenly to obtain a mixed solution.

[0028] The mixed solution is ultrasonically dispersed, and then the temperature is adjusted to 65-70 °C, and it is kept warm and stirred for a period of time to obtain the yttrium sol.

[0029] Preferably, the mixing ratio of yttrium nitrate to deionized water is 20-30 mmol∶100-150 ml.

[0030] Preferably, the molar ratio of yttrium nitrate to citric acid is 1∶2-3.

[0031] According to the second aspect of the present invention, an adsorbent for chemical ruthenium removal is provided, which is prepared by the above-mentioned preparation method and has a porous structure composed of nano-yttrium oxide and nano-carbon particles.

[0032] Preferably, the specific surface area of the adsorbent is 118-125 m / g, and the porosity is 70-75%.

[0033] According to the third aspect of the present invention, an application of the above-mentioned adsorbent for chemical ruthenium removal is provided, which is used for adsorbing ruthenium tetroxide gas and enabling a chemical reaction between the ruthenium tetroxide gas and the yttrium oxide component in the adsorbent.

[0034] Preferably, the temperature of the chemical reaction is 900-950 °C.

[0035] Beneficial effects:

[0036] The adsorbent for chemical ruthenium removal of the present invention, its preparation method and application, the adsorbent is a yttrium oxide-based adsorbent, that is, based on nano-yttrium oxide. This yttrium oxide-based adsorbent has a porous structure composed of nano-yttrium oxide and a large number of nano-scale carbon particles, and there are abundant pores inside. The sizes of these pores range from a few nanometers to dozens of nanometers, so that the yttrium oxide-based adsorbent has an extremely high specific surface area and porosity. This unique pore structure provides a large number of active sites for the subsequent adsorption process, thereby greatly enhancing its adsorption capacity and improving the adsorption capacity, and can adsorb ruthenium tetroxide gas in the introduced gas to achieve the effect of removing ruthenium.

[0037] Moreover, through the van der Waals force interaction between the yttrium oxide-based adsorbent and ruthenium tetroxide gas, combined with its large specific surface area, it has a higher surface energy, and the adsorption capacity is greatly improved. Therefore, it can better attract and fix the surrounding ruthenium tetroxide gas to achieve a better ruthenium removal effect.

[0038] In addition to having excellent physical adsorption ability, the yttrium-based adsorbent also exhibits strong chemisorption characteristics. At high temperatures, when ruthenium tetroxide gas reacts chemically with the yttrium component in the yttrium-based adsorbent, the reaction formula is Y2O3 + 2RuO2 → Y2Ru2O7, thus forming a chemisorption effect and further enhancing the adsorption and fixation of ruthenium tetroxide gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a diagram of the preparation method of the adsorbent for chemical ruthenium removal in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0041] Aiming at the problems of existing ruthenium removal adsorbents such as low adsorption capacity, the present invention discloses a preparation method of an adsorbent for chemical ruthenium removal, including:

[0042] S1, mixing yttrium sol with carrier microspheres, performing vacuum impregnation treatment to make the carrier microspheres adsorb yttrium sol, and then filtering to obtain a composite;

[0043] S2, drying the composite to obtain a dried body;

[0044] S3, calcining the dried body, and after cooling, obtaining an adsorbent for chemical ruthenium removal based on yttrium oxide.

[0045] Correspondingly, the present invention also provides an adsorbent for chemical ruthenium removal, which is prepared by the above-mentioned preparation method and has a porous structure composed of nano yttrium oxide and nano carbon particles.

[0046] Correspondingly, the present invention also provides an application of the above-mentioned adsorbent for chemical ruthenium removal, which is used to adsorb ruthenium tetroxide gas and enable the chemical reaction between ruthenium tetroxide gas and yttrium oxide in the adsorbent.

[0047] Example 1

[0048] As Figure 1 shown, this embodiment discloses a preparation method of an adsorbent for chemical ruthenium removal, including the following steps S1 to S3:

[0049] S1, mixing the yttrium sol and the carrier microspheres, performing vacuum impregnation treatment to allow the carrier microspheres to adsorb the yttrium sol, and then filtering to obtain a composite.

[0050] In some embodiments, the mass ratio of the yttrium sol to the carrier microspheres is 3 to 4: 1. Experiments have found that at this ratio, the optimal active ingredient ratio of the yttrium oxide-based adsorbent can be obtained, which can improve the adsorption efficiency of the adsorbent.

[0051] In some embodiments, the vacuum level during the vacuum impregnation process is 0.1 to 0.15 Pa. Experiments have found that impregnation at this vacuum level can enhance the combination of the two and improve dispersion uniformity, resulting in a more uniform dispersion of yttrium oxide in the yttrium oxide-based adsorbent prepared by this method, thereby ensuring uniform adsorption performance overall. The vacuum impregnation treatment lasts for 2 to 3 hours, preferably 2 hours.

[0052] S2, drying the composite to obtain a dried product;

[0053] In some embodiments, the drying temperature is 50-55° C. and the drying time is 10-11 hours to ensure that the moisture is fully removed to prevent the moisture from affecting the subsequent formation of the porous structure.

[0054] S3, calcining the dried product to form a porous structure composed of nano-yttrium oxide and a large number of nano-scale carbon particles, and cooling the product to obtain a yttrium oxide-based adsorbent for chemical ruthenium removal.

[0055] In some embodiments, the calcination treatment includes: first heating the temperature to 230-235°C at a rate of 3-4°C / min and keeping it warm for 30-40 minutes; then heating the temperature to 550-600°C at a rate of 5-6°C / min and keeping it warm for 1-1.5 hours to ensure that a yttrium oxide-based adsorbent with a rich porous structure is obtained.

[0056] In some embodiments, the carrier microspheres are prepared according to the following steps:

[0057] Add methyl acrylate and deionized water to the reactor in sequence, and stir and mix for a period of time, for example, for 10 to 11 minutes;

[0058] Introduce protective gas into the reactor and exhaust the air in the reactor;

[0059] Add an initiator, then heat in a water bath for a period of time, for example, 40 to 50 minutes, and then stir at a speed of 450 to 500 rpm for a period of time, for example, 30 to 40 minutes, and then cool to room temperature to obtain a mixture;

[0060] Centrifuge the mixture at a rotational speed of 12,000 - 13,000 r / min, collect the precipitate, wash it, and dry it to obtain the carrier microspheres.

[0061] By using the above-mentioned carrier microspheres and the carrier microsphere confinement growth technology, this method can adsorb, carry, and disperse yttrium oxide. After calcination, a heterojunction interface is formed between the nano-carbon framework formed by calcining the carrier microspheres and the yttrium oxide nanoparticles, realizing the directional anchoring of nano-yttrium oxide and the collaborative construction of a porous carbon framework, forming an interconnected mesoporous network, and obtaining a yttrium oxide-based adsorbent with a rich pore structure, which can provide a large number of active sites and significantly improve the adsorption capacity for ruthenium tetroxide through the charge transfer effect.

[0062] In some embodiments, the mixing volume ratio of methyl acrylate to deionized water is 1:10 - 15.

[0063] In some embodiments, the protective gas is nitrogen.

[0064] In some embodiments, the initiator is potassium peroxide, and its dosage is 5 - 6% of the mass of methyl acrylate.

[0065] In some embodiments, the washing is carried out with deionized water, and the drying temperature of the mixture is 55 - 60 °C.

[0066] In some embodiments, the yttrium sol is prepared according to the following steps:

[0067] Add yttrium nitrate to deionized water, stir and mix evenly to obtain a yttrium nitrate solution;

[0068] Add citric acid to the above yttrium nitrate solution, adjust the temperature to 30 - 35 °C, and stir evenly to obtain a mixed solution;

[0069] Perform ultrasonic dispersion on the mixed solution for 5 - 6 min, then adjust the temperature to 65 - 70 °C, and keep stirring for a period of time, for example, keep stirring for 2 - 2.5 h to obtain the yttrium sol.

[0070] By adopting the design of the yttrium nitrate - citric acid complex yttrium sol precursor, this method can facilitate its impregnation and dispersion in the carrier microspheres, and then form yttrium oxide nanocrystals with a high defect concentration under calcination conditions, with more surface active sites, obtaining highly active nano-yttrium oxide.

[0071] In some embodiments, the mixing ratio of yttrium nitrate to deionized water is 20 - 30 mmol:100 - 150 ml.

[0072] In some embodiments, the molar ratio of yttrium nitrate to citric acid is 1:2 - 3.

[0073] The preparation method of the adsorbent for chemical ruthenium removal in this embodiment adopts a three-step method of emulsion polymerization to prepare carrier microspheres → vacuum impregnation with yttrium sol → gradient calcination, achieving uniform dispersion of nano-yttrium oxide in the carbon framework. The prepared adsorbent is a yttrium oxide-based adsorbent, that is, based on nano-yttrium oxide. This yttrium oxide-based adsorbent has a porous structure composed of nano-yttrium oxide and a large number of nano-scale carbon particles, and there are abundant pores inside. The sizes of these pores range from a few nanometers to dozens of nanometers, so that the yttrium oxide-based adsorbent has an extremely high specific surface area and porosity. The specific surface area of the adsorbent reaches 118 - 125 m / g, and the porosity reaches 70 - 75%. This unique pore structure provides a large number of active sites for the subsequent adsorption process. Compared with traditional vinylpyridine-based adsorbents, the density of active sites is increased by 3 - 4 times, thereby greatly enhancing its adsorption capacity and improving the adsorption capacity. It can adsorb ruthenium tetroxide gas in the introduced gas to achieve the effect of ruthenium removal.

[0074] Moreover, through the van der Waals force interaction between the yttrium oxide-based adsorbent and ruthenium tetroxide gas, combined with its large specific surface area and higher surface energy, the adsorption capacity is greatly improved. Therefore, it can better attract and fix the surrounding ruthenium tetroxide gas to achieve a better ruthenium removal effect.

[0075] In addition, in addition to having excellent physical adsorption ability, the yttrium oxide-based adsorbent also exhibits strong chemisorption characteristics. At high temperatures, when ruthenium tetroxide gas reacts chemically with the yttrium oxide component in the yttrium oxide-based adsorbent, the reaction formula is Y2O3 + 2RuO2 → Y2Ru2O7, thereby forming a chemisorption effect and further improving the adsorption and fixation effect on ruthenium tetroxide gas.

[0076] Example 2

[0077] This embodiment discloses an adsorbent for chemical ruthenium removal, which is prepared by the above-mentioned preparation method. The adsorbent has a porous structure composed of nano-yttrium oxide and nano-carbon particles.

[0078] In some embodiments, the specific surface area of the adsorbent is 118 - 125 m / g, and the porosity is 70 - 75%.

[0079] Example 3

[0080] This embodiment discloses an application of the above-mentioned adsorbent for chemical ruthenium removal, which is used for physically adsorbing ruthenium tetroxide gas and enabling a chemical reaction between ruthenium tetroxide gas and the yttrium oxide component in the adsorbent to achieve a chemisorption effect.

[0081] Specifically, place the adsorbent described above in a container (such as an adsorption column), and pass a gas containing ruthenium tetroxide gas (such as the off-gas from spent fuel reprocessing) into the above container. Utilize the unique structure and excellent adsorption performance of the adsorbent to adsorb the ruthenium tetroxide gas and cause a chemical reaction under high-temperature conditions of 900-950 °C, thereby removing the ruthenium tetroxide gas and achieving the effect of removing ruthenium.

[0082] Example 4

[0083] This example discloses a preparation method of an adsorbent for chemical ruthenium removal, and the steps include:

[0084] Prepare carrier microspheres: Add methyl acrylate and deionized water to the reaction kettle in a volume ratio of 1:10 in sequence, and then stir and mix for 10 min; then introduce nitrogen into the reaction kettle to discharge the air in the reaction kettle; then add potassium peroxide, and the addition amount of potassium peroxide is 5% of the mass of methyl acrylate, and keep warm in a water bath for 40 min; then stir at a speed of 450 r / min for 30 min, cool to room temperature, obtain a mixture, centrifuge the mixture at a speed of 12,000 r / min, collect the precipitate, wash with deionized water, and place it in a drying oven to dry at 55 °C for 10 h to obtain carrier microspheres.

[0085] Prepare yttrium sol: Add yttrium nitrate to deionized water, and the mixing ratio of yttrium nitrate to deionized water is 20 mmol:100 mL, stir and mix evenly to obtain a yttrium nitrate solution; add citric acid to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid is 1:2, adjust the temperature to 30 °C, stir for 10 min to obtain a mixed solution; then ultrasonically disperse the mixed solution for 5 min, and then adjust the temperature to 65 °C and keep warm and stir for 2 h to obtain yttrium sol.

[0086] Add the prepared yttrium sol and carrier microspheres to the vacuum impregnation reaction in a mass ratio of 3:1, mix, and perform vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment is 0.1 Pa and the time is 2 h to enable the carrier microspheres to adsorb the yttrium sol, and then filter to obtain a composite body;

[0087] Place the composite body in a drying oven and perform a drying treatment on the composite body. The drying temperature is 50 °C and the time is 10 h to obtain a dried body;

[0088] Add the dried body to a tubular furnace for calcination treatment. The calcination process includes: first heat up to 230 °C at a rate of 3 °C / min, keep warm for 30 min, and then heat up to 550 °C at a rate of 5 °C / min and keep warm for 1 h to complete the calcination treatment; then cool, and after cooling to room temperature, obtain an adsorbent for chemical ruthenium removal based on yttrium oxide.

[0089] Example 5

[0090] This embodiment discloses a preparation method of an adsorbent for chemical ruthenium removal, and the steps include:

[0091] Preparing carrier microspheres: Methyl acrylate and deionized water are sequentially added to a reaction kettle according to a volume ratio of 1:12, and then stirred and mixed for 10 min; then nitrogen is introduced into the reaction kettle to discharge the air in the reaction kettle; then potassium peroxide is added, and the addition amount of potassium peroxide is 5% of the mass of methyl acrylate, and the water bath is kept warm for 40 min; then stirring is carried out at a speed of 450 r / min for 30 min, and after cooling to room temperature, a mixture is obtained, and the mixture is centrifuged at a speed of 12000 r / min, the precipitate is collected, washed with deionized water, and placed in a drying oven for drying at 55 °C for 10 h to obtain carrier microspheres.

[0092] Preparing yttrium sol: Yttrium nitrate is added to deionized water, and the mixing ratio of yttrium nitrate to deionized water is 25 mmol:125 mL, and stirred and mixed evenly to obtain a yttrium nitrate solution; citric acid is added to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid is 1:2, the temperature is adjusted to 30 °C, and stirred for 10 min to obtain a mixed solution; then the mixed solution is ultrasonically dispersed for 5 min, and then the temperature is adjusted to 65 °C and kept warm and stirred for 2 h to obtain yttrium sol.

[0093] The yttrium sol prepared above and the carrier microspheres are added to a vacuum impregnation reaction according to a mass ratio of 3:1, mixed, and subjected to vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment is 0.12 Pa, and the time is 2 h to enable the carrier microspheres to adsorb the yttrium sol, and then filtered to obtain a composite body;

[0094] The composite body is placed in a drying oven and dried. The drying temperature is 50 °C and the time is 10 h to obtain a dried body;

[0095] The dried body is added to a tubular furnace for calcination treatment. The calcination process includes: first heating at a rate of 3 °C / min to 230 °C, keeping warm for 30 min, and then heating at a rate of 5 °C / min to 555 °C, keeping warm for 1 h to complete the calcination treatment; then cooling, and after cooling to room temperature, an adsorbent for chemical ruthenium removal based on yttrium oxide is obtained.

[0096] Example 6

[0097] This embodiment discloses a preparation method of an adsorbent for chemical ruthenium removal, and the steps include:

[0098] Preparation of carrier microspheres: Methyl acrylate and deionized water were sequentially added to a reaction kettle at a volume ratio of 1:14, and then stirred and mixed for 10 min; then nitrogen was introduced into the reaction kettle to discharge the air in the reaction kettle; then potassium peroxide was added, and the addition amount of potassium peroxide was 5% of the mass of methyl acrylate, and the mixture was kept warm in a water bath for 40 min; then it was stirred at a speed of 450 r / min for 30 min. After cooling to room temperature, a mixture was obtained. The mixture was centrifuged at a speed of 12,000 r / min, the precipitate was collected, washed with deionized water, and dried in a drying oven at 55 °C for 10 h to obtain the carrier microspheres.

[0099] Preparation of yttrium sol: Yttrium nitrate was added to deionized water, and the mixing ratio of yttrium nitrate to deionized water was 22 mmol:130 mL. After stirring and mixing evenly, a yttrium nitrate solution was obtained; citric acid was added to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid was 1:2. The temperature was adjusted to 30 °C and stirred for 10 min to obtain a mixed solution; then the mixed solution was ultrasonically dispersed for 5 min, and then the temperature was adjusted to 65 °C and kept warm and stirred for 2 h to obtain the yttrium sol.

[0100] The yttrium sol prepared above and the carrier microspheres were added to a vacuum impregnation reaction at a mass ratio of 3:1, mixed, and subjected to vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment was 0.13 Pa and the time was 2 h to enable the carrier microspheres to adsorb the yttrium sol, and then filtered to obtain a composite.

[0101] The composite was placed in a drying oven and dried. The drying temperature was 50 °C and the time was 10 h to obtain a dried body.

[0102] The dried body was added to a tubular furnace for calcination treatment. The calcination process included: first heating at a rate of 3 °C / min to 230 °C and keeping warm for 30 min, and then heating at a rate of 5 °C / min to 554 °C and keeping warm for 1 h to complete the calcination treatment; then cooling. After cooling to room temperature, an adsorbent for chemical ruthenium removal based on yttrium oxide was obtained.

[0103] Example 7

[0104] This example discloses a preparation method of an adsorbent for chemical ruthenium removal. The steps include:

[0105] Preparation of carrier microspheres: Methyl acrylate and deionized water were sequentially added to a reaction kettle at a volume ratio of 1:13, and then stirred and mixed for 10 min; nitrogen was then introduced into the reaction kettle to discharge the air in the reaction kettle; then potassium peroxide was added, and the addition amount of potassium peroxide was 5% of the mass of methyl acrylate, and the mixture was kept warm in a water bath for 40 min; then stirred at a speed of 450 r / min for 30 min, and after cooling to room temperature, a mixture was obtained. The mixture was centrifuged at a speed of 12,000 r / min, the precipitate was collected, washed with deionized water, and dried in a drying oven at 55 °C for 10 h to obtain the carrier microspheres.

[0106] Preparation of yttrium sol: Yttrium nitrate was added to deionized water, and the mixing ratio of yttrium nitrate to deionized water was 26 mmol:140 mL, and stirred and mixed evenly to obtain a yttrium nitrate solution; citric acid was added to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid was 1:2, the temperature was adjusted to 30 °C, and stirred for 10 min to obtain a mixed solution; then the mixed solution was ultrasonically dispersed for 5 min, and then the temperature was adjusted to 65 °C and kept warm and stirred for 2 h to obtain the yttrium sol.

[0107] The yttrium sol prepared above and the carrier microspheres were added to a vacuum impregnation reaction at a mass ratio of 3:1, mixed, and subjected to vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment was 0.12 Pa and the time was 2 h to enable the carrier microspheres to adsorb the yttrium sol, and then filtered to obtain a composite;

[0108] The composite was placed in a drying oven and dried. The drying temperature was 50 °C and the time was 10 h to obtain a dried body;

[0109] The dried body was added to a tubular furnace for calcination treatment. The calcination process included: first heating at a rate of 3 °C / min to 230 °C and holding for 30 min, and then heating at a rate of 5 °C / min to 558 °C and holding for 1 h to complete the calcination treatment; then cooling, and after cooling to room temperature, an adsorbent for chemical ruthenium removal based on yttrium oxide was obtained.

[0110] Example 8

[0111] This example discloses a preparation method of an adsorbent for chemical ruthenium removal. The steps include:

[0112] Preparation of carrier microspheres: Methyl acrylate and deionized water were sequentially added to a reaction kettle at a volume ratio of 1:15, and then stirred and mixed for 10 min; then nitrogen was introduced into the reaction kettle to discharge the air in the reaction kettle; then potassium peroxide was added, and the addition amount of potassium peroxide was 5% of the mass of methyl acrylate, and the mixture was kept warm in a water bath for 40 min; then stirred at a speed of 450 r / min for 30 min, cooled to room temperature, and a mixture was obtained. The mixture was centrifuged at a speed of 12,000 r / min, the precipitate was collected, washed with deionized water, and dried in a drying oven at 55 °C for 10 h to obtain carrier microspheres.

[0113] Preparation of yttrium sol: Yttrium nitrate was added to deionized water, and the mixing ratio of yttrium nitrate to deionized water was 30 mmol:150 mL, and stirred and mixed evenly to obtain a yttrium nitrate solution; citric acid was added to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid was 1:2, the temperature was adjusted to 30 °C, and stirred for 10 min to obtain a mixed solution; then the mixed solution was ultrasonically dispersed for 5 min, and then the temperature was adjusted to 65 °C and kept warm and stirred for 2 h to obtain yttrium sol.

[0114] The prepared yttrium sol and carrier microspheres were added to a vacuum impregnation reaction at a mass ratio of 3:1, mixed, and subjected to vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment was 0.15 Pa and the time was 2 h to enable the carrier microspheres to adsorb the yttrium sol, and then filtered to obtain a composite.

[0115] The composite was placed in a drying oven and dried at a drying temperature of 50 °C for 10 h to obtain a dried body.

[0116] The dried body was added to a tubular furnace for calcination treatment. The calcination process included: first heating at a rate of 3 °C / min to 230 °C and keeping warm for 30 min, and then heating at a rate of 5 °C / min to 600 °C and keeping warm for 1 h to complete the calcination treatment; then cooled, and after cooling to room temperature, an adsorbent for chemical ruthenium removal based on yttrium oxide was obtained.

[0117] Example 9

[0118] This example discloses a preparation method of an adsorbent for chemical ruthenium removal. The steps include:

[0119] Preparation of carrier microspheres: Methyl acrylate and deionized water were sequentially added to a reaction kettle at a volume ratio of 1:11, and then stirred and mixed for 10 min; nitrogen was then introduced into the reaction kettle to discharge the air in the reaction kettle; then potassium peroxide was added, and the addition amount of potassium peroxide was 6% of the mass of methyl acrylate, and the mixture was kept warm in a water bath at 50 °C for 50 min; then stirred at a speed of 500 r / min for 40 min, cooled to room temperature, and a mixture was obtained. The mixture was centrifuged at a speed of 13000 r / min, the precipitate was collected, washed with deionized water, and dried in a drying oven at 60 °C for 11 h to obtain carrier microspheres.

[0120] Preparation of yttrium sol: Yttrium nitrate was added to deionized water, and the mixing ratio of yttrium nitrate to deionized water was 20 mmol:150 mL, and stirred and mixed evenly to obtain a yttrium nitrate solution; citric acid was added to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid was 1:3, the temperature was adjusted to 35 °C, and stirred for 10 min to obtain a mixed solution; then the mixed solution was ultrasonically dispersed for 6 min, and then the temperature was adjusted to 70 °C and kept warm and stirred for 2.5 h to obtain yttrium sol.

[0121] The prepared yttrium sol and carrier microspheres were added to a vacuum impregnation reaction at a mass ratio of 4:1, mixed, and subjected to vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment was 0.15 Pa and the time was 3 h to enable the carrier microspheres to adsorb the yttrium sol, and then filtered to obtain a composite.

[0122] The composite was placed in a drying oven and subjected to drying treatment. The drying temperature was 55 °C and the time was 11 h to obtain a dried body.

[0123] The dried body was added to a tubular furnace for calcination treatment. The calcination process included: first heating at a rate of 4 °C / min to 235 °C, holding for 35 min, and then heating at a rate of 6 °C / min to 600 °C, holding for 1.5 h to complete the calcination treatment; then cooling, and after cooling to room temperature, an adsorbent for chemical ruthenium removal based on yttrium oxide was obtained.

[0124] Example 10

[0125] This example discloses a preparation method of an adsorbent for chemical ruthenium removal. The steps include:

[0126] Preparation of carrier microspheres: Methyl acrylate and deionized water were sequentially added to a reaction kettle at a volume ratio of 1:13, and then stirred and mixed for 10 min; then nitrogen was introduced into the reaction kettle to discharge the air in the reaction kettle; then potassium peroxide was added, and the addition amount of potassium peroxide was 5.5% of the mass of methyl acrylate, and the mixture was kept warm in a water bath for 40 min; then it was stirred at a speed of 450 r / min for 30 min, and after cooling to room temperature, a mixture was obtained. The mixture was centrifuged at a speed of 12,000 r / min, the precipitate was collected, washed with deionized water, and placed in a drying oven for drying at 60 °C for 10 h to obtain the carrier microspheres.

[0127] Preparation of yttrium sol: Yttrium nitrate was added to deionized water, and the mixing ratio of yttrium nitrate to deionized water was 30 mmol:100 mL, and it was stirred and mixed evenly to obtain a yttrium nitrate solution; citric acid was added to the obtained yttrium nitrate solution, and the molar ratio of yttrium nitrate to citric acid was 1:2.5. The temperature was adjusted to 30 °C and stirred for 10 min to obtain a mixed solution; then the mixed solution was ultrasonically dispersed for 5 min, and then the temperature was adjusted to 65 °C and kept warm and stirred for 2 h to obtain the yttrium sol.

[0128] The prepared yttrium sol and carrier microspheres were added to a vacuum impregnation reaction at a mass ratio of 3.5:1, mixed, and subjected to vacuum impregnation treatment. The vacuum degree of the vacuum impregnation treatment was 0.14 Pa and the time was 2 h to enable the carrier microspheres to adsorb the yttrium sol, and then filtered to obtain a composite.

[0129] The composite was placed in a drying oven and dried at a drying temperature of 60 °C for 10 h to obtain a dried body.

[0130] The dried body was added to a tubular furnace for calcination treatment. The calcination process included: first heating at a rate of 3 °C / min to 230 °C and keeping warm for 40 min, and then heating at a rate of 5 °C / min to 590 °C and keeping warm for 1 h to complete the calcination treatment; then cooling, and after cooling to room temperature, an adsorbent for chemical ruthenium removal based on yttrium oxide was obtained.

[0131] Comparative Example 1

[0132] This Comparative Example 1 was basically the same as Example 4, except that:

[0133] On the basis of Example 1, carrier microspheres were not used during the preparation process, and the rest of the technical solutions remained unchanged.

[0134] The following tests were carried out:

[0135] (1) Tests on the theoretical maximum capture capacity of ruthenium tetroxide were carried out on CaO, CaCO3, SrCO3, BaCO3, Y2O3, and Nd2O3 under the same conditions respectively, and the results are shown in Table 1.

[0136] Table 1

[0137] Capture ability of g-Ru / g-material CaO 1.82 <![CDATA[CaCO3]]> 1.01 <![CDATA[SrCO3]]> 0.68 <![CDATA[BaCO3]]> 0.51 <![CDATA[Y2O3]]> 0.89 <![CDATA[Nd2O3]]> 0.20

[0138] As can be seen from Table 1, the capture capabilities of various materials for Ru (ruthenium) are not the same. However, alkaline earth metal compounds such as BaCO3 and SrCO3 have harmful effects on human health, and chemical methods using alkaline earth metal compounds will also cause problems such as partial blockage of the flow channel due to the flying out of fine powder; the product of the reaction between CaO and ruthenium tetroxide is CaRuO3, and its stability is relatively poor; while the product of the reaction between Y2O3 and ruthenium tetroxide is Y2Ru2O7, and its thermal stability is as high as 1400 °C, which is significantly better than that of CaO. Therefore, through comprehensive analysis, using Y2O3 as the ruthenium tetroxide adsorbent material is the best choice.

[0139] (2) The specific surface areas of the adsorbents prepared in Examples 4 to 10 and Comparative Example 1 were tested, and the results are shown in Table 2.

[0140] Table 2

[0141]

[0142]

[0143] As can be seen from Table 2, the preparation method of the present invention can obtain yttrium-based adsorbents with a higher specific surface area, thereby having a larger adsorption capacity and being able to improve the adsorption efficiency of yttrium-based adsorbents.

[0144] (3) The adsorbents prepared in Examples 4 to 10 and Comparative Example 1 were respectively used to capture ruthenium tetroxide gas (i.e., the adsorption capacity). Among them, the wind speed during the test process was 0.5 m / s, and the temperature was 900 °C. The results are shown in Table 3.

[0145] Table 3

[0146]

[0147] As can be seen from Table 3, the yttrium-based adsorbent prepared by the preparation method of the present invention can maintain a high ruthenium tetroxide capture capacity, which is closer to the maximum theoretical adsorption value of yttrium, while the capture capacity of the adsorbent used in Comparative Example 1 decreases under the same conditions.

[0148] In summary, the preparation method of the present invention can improve the adsorption capacity of the adsorbent, enhance the adsorption ability, prepare an adsorbent with a large adsorption capacity, a strong adsorption ability, and good ruthenium removal effect.

[0149] It is understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A preparation method of an adsorbent for chemical ruthenium removal, characterized in that, Comprising: S1. Mix yttrium sol with carrier microspheres, conduct vacuum impregnation treatment to enable the carrier microspheres to adsorb the yttrium sol, and then filter to obtain a composite; S2. Conduct drying treatment on the composite to obtain a dried body; S3. Conduct calcination treatment on the dried body, and after cooling, obtain an adsorbent for chemical ruthenium removal based on yttrium oxide.

2. The preparation method of the adsorbent for chemical ruthenium removal according to claim 1, characterized in that, The mixing mass ratio of the yttrium sol to the carrier microspheres is 3 - 4:

1.

3. The preparation method of the adsorbent for chemically removing ruthenium according to claim 1, characterized in that, The vacuum degree in the vacuum impregnation treatment process is 0.1 - 0.15 Pa.

4. The preparation method of the adsorbent for chemical ruthenium removal according to claim 1, characterized in that, The temperature of the drying treatment is 50 - 55 °C, and the time is 2 - 3 h.

5. The preparation method of the adsorbent for chemical ruthenium removal according to claim 1, characterized in that, The calcination treatment includes: First, heat up to 230 - 235 °C at a rate of 3 °C / min and keep warm for 30 - 40 min; Then, heat up to 550 - 600 °C at a rate of 5 °C / min and keep warm for 1 - 1.5 h.

6. The preparation method of the adsorbent for chemical ruthenium removal according to any one of claims 1 to 5, characterized in that, The carrier microspheres are prepared according to the following steps: Add methyl acrylate and deionized water to the reaction kettle in sequence and stir and mix; Introduce a protective gas into the reaction kettle to discharge the air in the reaction kettle; Add an initiator, then keep warm in a water bath for a period of time, stir at a rotation speed of 450 - 500 r / min for a period of time, and then cool to room temperature to obtain a mixture; Conduct centrifugal separation on the mixture, collect the precipitate, wash, and dry to obtain the carrier microspheres.

7. The preparation method of the adsorbent for chemical ruthenium removal according to claim 6, characterized in that, The mixing volume ratio of the methyl acrylate to the deionized water is 1:10 - 15.

8. The preparation method of the adsorbent for chemically removing ruthenium according to claim 6, characterized in that, The initiator is potassium peroxide, and its dosage is 5 - 6% of the mass of methyl acrylate.

9. The preparation method of the adsorbent for chemical ruthenium removal according to claim 6, characterized in that, The drying temperature of the mixture is 55 - 60 °C.

10. The preparation method of the adsorbent for chemical ruthenium removal according to claim 6, characterized in that, The yttrium sol is prepared according to the following steps: Add yttrium nitrate to deionized water, stir and mix evenly to obtain a yttrium nitrate solution; Add citric acid to the above yttrium nitrate solution, adjust the temperature to 30 - 35 °C, and stir evenly to obtain a mixed solution; Conduct ultrasonic dispersion on the mixed solution, then adjust the temperature to 65 - 70 °C, keep warm and stir for a period of time to obtain the yttrium sol.

11. The preparation method of the adsorbent for chemical ruthenium removal according to claim 10, characterized in that, The mixing ratio of the yttrium nitrate to the deionized water is 20 - 30 mmol:100 - 150 ml.

12. The preparation method of the adsorbent for chemical ruthenium removal according to claim 11, wherein, The molar ratio of the yttrium nitrate to the citric acid is 1:2 - 3.

13. An adsorbent for chemical ruthenium removal, characterized in that, Prepared by using the preparation method according to any one of claims 1 - 12, having a porous structure composed of nano yttrium oxide and nano carbon particles.

14. The adsorbent for chemical ruthenium removal according to claim 13, wherein The specific surface area of the adsorbent is 118 - 125 m / g, and the porosity is 70 - 75%.

15. Use of the adsorbent for chemical ruthenium removal according to any one of claims 13 to 14, characterized in that, For adsorbing ruthenium tetroxide gas and enabling a chemical reaction between the ruthenium tetroxide gas and the yttrium oxide component in the adsorbent.

16. The application of the adsorbent for chemically removing ruthenium according to claim 15, wherein, The temperature of the chemical reaction is 900 - 950 °C.

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