Carrier-supported silicon-zirconium composite adsorbent, preparation method and application thereof

Abstract

The present application relates to a carrier-supported silicon-zirconium composite adsorbent, a preparation method and application thereof. The carrier-supported silicon-zirconium composite adsorbent is in a microcrystalline state, wherein the carrier-supported silicon-zirconium composite adsorbent has substantially no sharp X-ray diffraction peak in the X-ray diffraction spectrum. Preferably, the carrier-supported silicon-zirconium composite adsorbent has a half-peak width in the range of 15° to 30°, preferably in the range of 18° to 29° in the X-ray diffraction spectrum. The adsorbent according to the present application can remove Sr 2+ , Ba 2+ , Co 2+ , uranyl ion (UO2 2+ ), Nd 3+ , Mg 2+ , Ca 2+ , Mn 2+ , Cs + , Rb + , Fe 2+ , Fe 3+ , Ce 3+ , Am 3+ , and can simultaneously adsorb and remove Sr 2+ , Co 2+ , Am 3+ and uranyl ion (UO2 2+ ) in a multi-nuclide waste liquid, achieving the purpose of efficient and convenient treatment of radioactive waste liquid. Moreover, the adsorption process composed of the above adsorbent and a cesium adsorbent can be directly applied to a radioactive waste liquid containing multi-nuclides, and the equipment is simple and has low energy consumption.

Description

Technical Field

[0001] This application relates to a zirconium-based adsorbent, specifically, to a carrier-supported silicon-zirconium composite adsorbent, its preparation method, and its application in the simultaneous adsorption and removal of multiple nuclides from spent fuel reprocessing and nuclear facility decommissioning waste liquids. Background Technology

[0002] The waste liquid from spent fuel reprocessing and nuclear facility decommissioning has a complex composition and contains multiple nuclides, such as... 90 Sr、 99 Tc, 137 Cs and α nuclides such as U, Np, Pu, and Am, with mass concentrations of 10 -6 For concentrations below mg / L, deep purification requires separation technologies with both high precision and high selectivity. Common treatment processes include evaporation and ion exchange. Typically, a single evaporation treatment can achieve a radionuclide decontamination factor of 10. 2 -10 3 Multi-stage evaporation treatment can reach 10 4 -10 6 The concentrated liquid formed by evaporation is generally solidified with cement to encapsulate radioactive nuclides within the cement solid phase. Methods for directly concentrating radioactive nuclides into the solid phase mainly include chemical precipitation, ion exchange, and selective adsorption. Chemical precipitation is a mature technology, but its decontamination efficiency is limited, and it is usually used as a pretreatment. Ion exchange resins have a broad-spectrum exchange and adsorption capacity for different types of nuclide ions or non-radioactive ions. However, due to their definite total exchange capacity, they are only suitable for treating waste liquids with low salinity. Under high salinity conditions, the resin quickly reaches saturation and fails due to the adsorption of salt ions. Compared with ion exchange resins, inorganic ion adsorbents have high selectivity for trace nuclides, are less affected by coexisting non-radioactive ions, and can characteristically and efficiently remove target nuclide ions from high-salinity radioactive waste liquids. Therefore, adsorbents are selective for nuclide ions, have a long service life, produce less solid waste, and also have strong radiation resistance and thermal stability. Therefore, inorganic adsorbent materials have been widely used in the field of radioactive waste liquid treatment in recent years.

[0003] A key characteristic of adsorbents is their specificity; typically, a single adsorbent can only adsorb one or a few nuclide ions with similar properties. Therefore, when treating radioactive waste containing multiple nuclides, multiple adsorbents need to be used in combination. As a common selective adsorbent, zirconium phosphate (ZPphosphate) adsorbents exhibit excellent adsorption and exchange performance for metal ions. Currently known zirconium phosphate (ZPphosphate) adsorbents include inorganic zirconium phosphate and organophosphonate zirconium. However, current research on organophosphonate zirconium is very limited. Chinese patent application CN102675364 discloses a method for preparing organophosphonate zirconium. In this patent, a fluorine complexation method is used to form a stable complex (ZrF6) between hydrofluoric acid and zirconium in zirconium oxychloride, which serves as the zirconium source. 2- Subsequently, during the reaction with the organophosphonic acid aminotrimethylphosphonic acid (AMTP), the complex ion (ZrE6) was utilized. 2- The equilibrium dissociation slowly releases Zr 4+ A slow reaction with organophosphonic acid forms zirconium organophosphonate with a regular spherical structure of about 10 micrometers. This material has both an ordered crystal structure and a good mesoporous structure. However, the preparation of this zirconium phosphonate adsorbent is complex and requires the use of highly corrosive hydrofluoric acid, which is not conducive to industrial application.

[0004] Therefore, the radioactive waste treatment industry urgently needs new zirconium phosphonate adsorbents suitable for industrial application. Summary of the Invention

[0005] In view of the above objectives, the present invention aims to design a novel zirconium-based inorganic adsorbent, which is effective for adsorbing Sr... 2+ Ba 2+ Co 2+ Uranyl ion (UO2) 2+ )Nd 3+ Mg 2+ Ca 2+ Mn 2+ Cs + 、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ (where Am) 3+ (Representing minor actinides and other rare earth nuclides) exhibits excellent adsorption properties, and can even simultaneously adsorb and remove Sr from multi-nucleon waste liquid. 2+ Co 2 + Am 3+ and uranyl ions (UO2) 2+ Therefore, this adsorbent can be combined with cesium adsorbents to form an engineering-grade fixed-bed adsorption device, which can efficiently treat common spent fuel nuclear facility radioactive waste liquids, while simultaneously adsorbing and removing Sr from multi-nuclear waste liquids.2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + 、Rb + It features simple equipment, low energy consumption, and the ability to remove multiple nuclides simultaneously.

[0006] Therefore, one aspect of this application provides a carrier-supported silicon-zirconium composite adsorbent, which is microcrystalline, wherein the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has substantially no sharp X-ray diffraction peaks. Preferably, the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (FWHM) in the range of 15° to 30°, and more preferably, it has a FWHM in the range of 18° to 29°.

[0007] Another aspect of the present invention provides a method for preparing a carrier-supported silicon-zirconium composite adsorbent, the method comprising the following steps:

[0008] i) subject the carrier to vacuum degassing at 0.1 atmospheres or less;

[0009] ii) An aqueous solution of a zirconium source with a certain degree of acidity is injected into the support to achieve a solid-liquid equilibrium state, and then dried to obtain an intermediate loaded with the zirconium source; and

[0010] iii) The obtained intermediate is mixed with a mixed solution of organophosphoric acid and metasilicate, and the reaction is carried out under sealed conditions to form the carrier-supported silicon-zirconium composite adsorbent.

[0011] The obtained carrier-supported silicon-zirconium composite adsorbent is microcrystalline, and the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent basically has no sharp X-ray diffraction peaks.

[0012] Preferably, the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (WHM) in the X-ray diffraction spectrum in the range of 15° to 30°, and more preferably, it has a WHM in the range of 18° to 29°.

[0013] Another aspect of the present invention provides the above-described carrier-supported silicon-zirconium composite adsorbent or the carrier-supported silicon-zirconium composite adsorbent prepared by the above method for adsorbing Sr. 2+ Ba 2+ Co 2+ Uranyl ion (UO2) 2+ )Nd 3+ Mg 2+ Ca 2+ Mn 2+ Cs +、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ Its uses.

[0014] Another aspect of the present invention provides the above-mentioned carrier-supported silicon-zirconium composite adsorbent or the carrier-supported silicon-zirconium composite adsorbent prepared by the above method for simultaneously adsorbing and removing Sr from multi-nucleoside waste liquid. 2+ Co 2+ Am 3 + and uranyl ions (UO2) 2+ The uses of ).

[0015] Another aspect of the present invention provides the above-mentioned carrier-supported silicon-zirconium composite adsorbent, or a combination of the above-mentioned carrier-supported silicon-zirconium composite adsorbent prepared by the above method and a cesium adsorbent, for simultaneously adsorbing and removing Sr from multi-nucleon waste liquid. 2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + and Rb + Its uses.

[0016] As mentioned above, the methods disclosed in the prior art for preparing organophosphonate zirconium have drawbacks such as complex processes, the need for highly corrosive hydrofluoric acid, and the impracticality for industrial application. Currently, the radioactive waste treatment industry requires novel zirconate adsorbents suitable for industrial application. The inventors of this invention have discovered that when using a zirconium source such as zirconium oxychloride and aminotrimethylenephosphonic acid (C3H... 12When using NO9P3)ATMP as a raw material to prepare zirconium phosphonate, the aminotrimethylene phosphonate microcrystalline active material composited with silicon oxide can be directly loaded onto the carrier microspheres, thereby easily preparing zirconium phosphonate adsorbents on an industrial scale. The carrier-supported silicon-zirconium composite adsorbent prepared above has a microcrystalline structure, which is structurally different from the zirconium phosphonate adsorbent with an ordered crystal structure prepared by the method disclosed in Chinese Patent CN102675364. Specifically, in the preparation method of the carrier-supported silicon-zirconium composite adsorbent according to the present invention, the zirconium source as a reactant is uniformly loaded onto a carrier with a high specific surface area, thereby forming highly dispersed zirconium oxychloride microcrystals on the carrier; the zirconium source in the form of small microcrystalline particles thus formed then reacts with aminotrimethylene phosphonic acid, and the resulting zirconium phosphonate product is also in the form of small crystals. In addition, during the formation of the zirconium phosphonate product, the additionally added metasilicate is rapidly hydrolyzed under the catalysis of the zirconium source in the form of a strong acid to form a silicon oxide film. This film coats the surface of the formed zirconium phosphonate microcrystals and inhibits further crystal growth. Therefore, the carrier-supported silicon-zirconium composite adsorbent prepared according to the method of the present invention has a microcrystalline structure and its X-ray diffraction spectrum has basically no sharp X-ray diffraction peaks, which is structurally different from the zirconium phosphonate adsorbent with an ordered crystal structure prepared by the method disclosed in CN102675364 (which has sharp X-ray diffraction peaks in its X-ray diffraction spectrum).

[0017] The inventors of this invention have also discovered that the carrier-supported silicon-zirconium composite adsorbent prepared according to the method of this invention exhibits particularly excellent adsorption performance for various metal ions, not only for Sr... 2+ Ba 2+ Co 2+ Uranyl ion (UO2) 2+ )Nd 3+ Mg 2 + Ca 2+ Mn 2+ Cs + 、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ (where Am) 3+ (Representing minor actinides and other rare earth nuclides) exhibits excellent adsorption properties, and can also simultaneously adsorb and remove Sr from multi-nucleon waste liquid. 2+ Co 2+ Am 3+ and uranyl ions (UO2) 2 +This was unforeseen prior to this application. The inventors of this invention also surprisingly discovered that the carrier-supported silicon-zirconium composite adsorbent according to the present invention, when combined with a cesium adsorbent, can achieve the adsorption of Sr in multi-nucleon waste liquid. 2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + and Rb + The adsorption and removal of [something] is an additional benefit.

[0018] Details of one or more embodiments of the present invention are set forth in the following description. Other features, objects, and advantages of the invention will become clear from the description and claims.

[0019] definition

[0020] When describing the contents of this invention, the absence of quantifiers (especially in the content of the claims) should be interpreted as covering both singular and plural forms, unless otherwise stated or clearly contradicted by the context.

[0021] Where a method is described as including or comprising specific process steps, it is expected that optional process steps not explicitly specified are not excluded from the method, and the method may also be constituted or composed of the process steps involved.

[0022] For simplicity, this paper only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an undefined range; and any lower limit can be combined with other lower limits to form an undefined range, just as any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can serve as its own lower or upper limit and be combined with any other point or individual value, or with other lower or upper limits, to form an undefined range.

[0023] In the context of this invention, the phrase "the carrier-supported silicon-zirconium composite adsorbent is microcrystalline" means that the crystals of the carrier-supported silicon-zirconium composite adsorbent are extremely small, even undetectable. Therefore, the carrier-supported silicon-zirconium composite adsorbent can also be considered amorphous.

[0024] When used in the context of "carrier-supported silicon-zirconium composite adsorbents," the term "substantially no sharp X-ray diffraction peaks" means that when the carrier-supported silicon-zirconium composite adsorbent is subjected to X-ray diffraction analysis, the resulting X-ray diffraction pattern contains no sharp peaks from the carrier-supported silicon-zirconium composite adsorbent, and all diffraction peaks have a full width at half maximum (FWHM) of at least 5° or greater. It is known that in X-ray diffraction patterns, "FWHM" refers to the distance between the intersection of a straight line drawn parallel to the base of each peak from the midpoint of its peak height and the two sides of the peak.

[0025] When used in the context of “carrier-supported silicon-zirconium composite adsorbent”, the term “substantially no hysteresis loop” means that when the carrier-supported silicon-zirconium composite adsorbent is tested for adsorption and desorption using a BJH pore size distribution analyzer via a nitrogen adsorption experiment, the adsorption and desorption amounts are substantially consistent, with no significant hysteresis phenomenon.

[0026] The terms "preferred" and "ideally" refer to embodiments of the invention that provide certain benefits in certain circumstances. However, other embodiments may also be preferred in the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the invention. Attached Figure Description

[0027] Figure 1 The image shows an XRD pattern of a carrier-supported silicon-zirconium composite adsorbent according to one embodiment of the present invention.

[0028] Figure 2 The adsorption-desorption curve of a carrier-supported silicon-zirconium composite adsorbent according to one embodiment of the present invention is shown.

[0029] Figure 3 The image shows the XRD pattern of a zirconium phosphonate adsorbent prepared according to the method disclosed in CN102675364.

[0030] Figure 4 The adsorption-desorption curves of zirconium phosphonate adsorbent prepared according to the method disclosed in CN102675364 are shown.

[0031] Figure 5 According to one embodiment of the present invention, a carrier-supported silicon-zirconium composite adsorbent for Sr 2+ Co 2+ and Nd 3 + Static adsorption isotherm of ions;

[0032] Figure 6 This is a block diagram illustrating the competitive adsorption of multiple ions by a carrier-supported silicon-zirconium composite adsorbent according to one embodiment of the present invention.

[0033] Figure 7 This is a static adsorption isotherm of uranyl ions on a carrier-supported silicon-zirconium composite adsorbent and a single carrier according to an embodiment of the present invention.

[0034] Figure 8 is a dynamic adsorption point diagram of various ions by a carrier-supported silicon-zirconium composite adsorbent according to an embodiment of the present invention, wherein... Figure 8A It is a dynamic adsorption diagram for Nd ions; Figure 8B It is a dynamic adsorption diagram for Sr ions; Figure 8C This is a dynamic adsorption diagram for Co ions. Detailed Implementation

[0035] As is well known, zirconium phosphonate adsorbents exhibit excellent adsorption and exchange performance for metal ions. However, current known methods for preparing zirconium phosphonate adsorbents are complex, require the use of highly corrosive hydrofluoric acid, and are not conducive to industrial application. Furthermore, the demand for higher-performance zirconium phosphonate adsorbents is constantly increasing in the radioactive waste treatment industry. Therefore, this invention provides a novel carrier-supported silicon-zirconium composite adsorbent.

[0036] According to embodiments of the present invention, a carrier-supported silicon-zirconium composite adsorbent is provided, which is microcrystalline, wherein the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent is substantially free of sharp X-ray diffraction peaks. In other words, when the carrier-supported silicon-zirconium composite adsorbent is subjected to X-ray diffraction analysis, the resulting X-ray diffraction pattern does not contain sharp peaks from the carrier-supported silicon-zirconium composite adsorbent, and the resulting diffraction peaks all have a full width at half maximum (FWHM) of at least 5° or greater. In some embodiments of the present invention, the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a FWHM in the range of 15° to 30°, preferably in the range of 18° to 29°. The above-mentioned X-ray diffraction pattern suggests that the carrier-supported silicon-zirconium composite adsorbent according to the present invention has a microcrystalline structure, which is structurally different from the zirconium phosphonate adsorbent with an ordered crystal structure prepared by the method disclosed in Chinese Patent CN102675364. The inventors of this invention have surprisingly discovered that the microcrystalline structure of the carrier-supported silicon-zirconium composite adsorbent according to the present invention is related not only to the use of a carrier but also to the silicon element incorporated therein. As described above, in the preparation method of the carrier-supported silicon-zirconium composite adsorbent according to the present invention, a zirconium source as a reactant is uniformly loaded onto a carrier with a high specific surface area, thereby forming highly dispersed zirconium oxychloride microcrystals on the carrier; the zirconium source in the form of small-particle microcrystals thus formed then reacts with aminotrimethylenephosphonic acid, and the resulting zirconium phosphonate product is also in the form of small crystals. In addition, during the formation of the zirconium phosphonate product, additionally added metasilicate is rapidly hydrolyzed under the catalysis of a strongly acidic zirconium source to form a silicon oxide film, which coats the surface of the formed zirconium phosphonate microcrystals and inhibits further crystal growth. Thus, the carrier-supported silicon-zirconium composite adsorbent prepared according to the method of the present invention has a microcrystalline structure.

[0037] In some embodiments of the present invention, the silicon in the carrier-supported silicon-zirconium composite adsorbent exists in the form of a silicon oxide coating, which is derived from metasilicates, preferably from sodium metasilicate, potassium metasilicate, or a combination thereof.

[0038] In some embodiments of the present invention, the carrier of the carrier-supported silicon-zirconium composite adsorbent includes inorganic oxides, activated carbon, or combinations thereof, preferably silica gel, titanium dioxide, zirconium oxide, activated carbon, or combinations thereof.

[0039] In one specific embodiment of the present invention, the carrier-supported silicon-zirconium composite adsorbent is a reaction product of an organophosphoric acid containing aminotrimethylphosphonic acid and zirconium oxychloride.

[0040] The carrier-supported silicon-zirconium composite adsorbent according to the present invention, having the above structure, is a particulate product with a particle size ranging from 0.3 to 1.2 mm. Furthermore, the carrier-supported silicon-zirconium composite adsorbent according to the present invention has a substantially uniform pore size, ranging from 2 nm to 3 nm. Such a carrier-supported silicon-zirconium composite adsorbent exhibits more stable adsorption-desorption performance and substantially lacks hysteresis loops characteristic of mesoporous structures.

[0041] The aforementioned carrier-supported silicon-zirconium composite adsorbent with a specific structure is prepared using the specific method of this invention. Therefore, another aspect of this invention relates to a method for preparing a carrier-supported silicon-zirconium composite adsorbent, the method comprising the following steps:

[0042] i) subject the carrier to vacuum degassing at 0.1 atmospheres or less, preferably at 0.01 atmospheres or less;

[0043] ii) An aqueous solution of a zirconium source with a certain degree of acidity is injected into the support to achieve a solid-liquid equilibrium state, and then dried to obtain an intermediate loaded with the zirconium source; and

[0044] iii) The obtained intermediate is mixed with a mixed solution of organophosphoric acid and metasilicate, and the reaction is carried out under sealed conditions to form the carrier-supported silicon-zirconium composite adsorbent.

[0045] The obtained carrier-supported silicon-zirconium composite adsorbent is microcrystalline, and the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has essentially no sharp X-ray diffraction peaks. Preferably, the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (WHM) in the range of 15° to 30°, and more preferably, it has a WHM in the range of 18° to 29°.

[0046] In step i) of the above method, the carrier undergoes deep vacuum degassing, thus possessing the largest specific surface area. Preferably, the carrier undergoes vacuum degassing at 0.1 atmospheres or less for 20 hours or longer, thereby ensuring that the original air in the carrier pores is removed, creating a negative pressure state within the pores. This facilitates the rapid adsorption of the zirconium-containing solution and allows it to enter almost all pores, which is beneficial for the high dispersion of zirconium nuclei and increases the zirconium loading.

[0047] In step ii) of the above method, a zirconium source, serving as a reaction raw material, is uniformly loaded onto a support with a high specific surface area, thereby forming highly dispersed zirconium oxychloride microcrystals on the support. The inventors of this invention have discovered that to obtain zirconium source microcrystals, the mass ratio of the support to the zirconium source can be adjusted. If the mass ratio of the zirconium source to the support is too large, the zirconium source microcrystal particles will be too large, which is detrimental to adsorption applications; if the mass ratio of the zirconium source to the support is too small, the content of the active component in the adsorbent will be too low, which is also detrimental to adsorption applications. Therefore, in some embodiments according to this invention, the mass ratio of the zirconium source to the support is controlled within the range of 1:1 to 1:5.

[0048] In step iii) of the above method, the zirconium source in the form of small-particle microcrystals formed in step ii) then reacts with aminotrimethylenephosphonic acid, and the resulting zirconium phosphonate product is also in the form of small crystals.

[0049] Furthermore, in step iii), when the zirconium source in the form of small microcrystalline particles reacts with aminotrimethylenephosphonic acid, the additionally added metasilicate rapidly hydrolyzes under the catalysis of the strongly acidic zirconium source to form a silicon oxide film. This film coats the surface of the formed zirconium phosphonate microcrystals, which can both enhance the binding force between the active particles and the support and inhibit further crystal growth. Thus, the support-supported silicon-zirconium composite adsorbent prepared according to the method of the present invention has a microcrystalline structure. The inventors of the present invention have discovered that a strong acidity is required in the system to achieve rapid hydrolysis of metasilicate. Therefore, in some embodiments of the present invention, the aqueous solution of the zirconium source has a pH value of 0.1 or lower.

[0050] Furthermore, during the subsequent reaction of the zirconium source in the form of small microcrystalline particles formed in step ii) above with aminotrimethylenephosphonic acid, the system is under sealed conditions, and the hydrothermal reaction is carried out at a temperature of 100-120°C for 20 hours or longer, preferably 24 hours or longer. These process conditions are also important for obtaining the microcrystalline carrier-supported silicon-zirconium composite adsorbent.

[0051] In some embodiments of the present invention, the concentration of the zirconium source aqueous solution is in the range of 30-50 wt%; and / or the concentration of the organophosphoric acid aqueous solution is in the range of 10-60 wt%; and / or the concentration of the metasilicate aqueous solution is in the range of 1-10 wt%.

[0052] In some embodiments of the present invention, the zirconium source is zirconium oxychloride; and / or the metasilicate includes sodium metasilicate, potassium metasilicate, or a combination thereof; and / or the organophosphoric acid includes aminotrimethylphosphonic acid.

[0053] In some embodiments of the present invention, the carrier comprises inorganic oxides, activated carbon, or combinations thereof, preferably silica gel, titanium dioxide, zirconium oxide, activated carbon, or combinations thereof.

[0054] In one specific embodiment of the present invention, the carrier-supported silicon-zirconium composite adsorbent according to the present invention can be prepared by the following industrial-scale process.

[0055] Zirconium oxychloride, sodium metasilicate, AMPT (trimethylmethylene phosphate), and particulate carriers were used as raw materials. The production equipment used was industrially known, including a forced-air drying oven, a double-cone reactor system, a vertical high-temperature and high-pressure reactor, a falling film absorption tower, and a self-circulating cleaning column system.

[0056] The specific production process is as follows:

[0057] 1) The silica gel carrier is sieved, preferably into particles of 0.3-1.2 mm, and loaded into a double cone dryer. The vacuum system is turned on and heated to thoroughly dry the carrier material and perform deep degassing. Once the vacuum level stabilizes to a certain value, the temperature is lowered to room temperature, and the vacuum pump is turned off, but the system is maintained under vacuum throughout the process. In this step, silica gel is the preferred carrier. Alternatively, the carrier can be activated carbon particles, titanium dioxide microspheres, or zirconium oxide microspheres.

[0058] 2) Prepare an aqueous solution of zirconium oxychloride with a concentration of 30-50 wt%. A measured amount of the solution is injected into a double-cone reactor using a pump. During this process, the double-cone reactor is kept rotating to allow the particles to flow and achieve uniform mixing of the solid and liquid phases. In this step, the mass ratio of zirconium oxychloride to the carrier is controlled within the range of 1:1 to 1:5.

[0059] 3) After the liquid injection is completed, seal the reactor and keep it rotating at room temperature for 5-10 hours to reach the impregnation equilibrium state.

[0060] 4) Start the heating and vacuum pump to carry out the material drying process. The volatile gas in this process contains hydrochloric acid. The design adopts a falling film absorption tower and uses NaOH to absorb and treat the tail gas to prevent the release of corrosive gases. The material is discharged after being completely dried and cooled to room temperature to obtain the intermediate Zr-support loaded with zirconium oxychloride.

[0061] 5) Prepare a mixed solution of AMPTA and sodium metasilicate in a vertical reactor. The concentration of AMPTA is 10-60 wt%, and the concentration of sodium metasilicate is 1-10 wt%. Under continuous stirring at room temperature, add the particulate intermediate Zr-support loaded with zirconium oxychloride to the vertical reactor. After sealing, react at room temperature for 1-2 hours, then heat to 100℃-120℃ and react for 24 hours. Due to the closed system, the reaction process is under high temperature and high pressure hydrothermal conditions. In this step, the molar ratio of AMPTA to Zr is 1:1 to 5:1, and the molar ratio of sodium metasilicate to zirconium oxychloride is 0.01 to 0.1.

[0062] 6) After the reaction is completed, the particles are dehydrated by centrifuge, dried at 100°C in a sealed drying room, sieved to remove fine powder, and preferably have a particle size of 0.3-1.2 mm.

[0063] 7) Load the crude product into the washing column, turn on the water treatment equipment of the washing system, and perform dynamic rinsing with pure water until the turbidity, pH value, and conductivity decrease to a certain level. Then stop rinsing and dry the product again at 100℃, and sieve it again to ensure that the optimal particle size is 0.3-1.2mm. During this washing process, the pH is neutral, the turbidity is controlled to be less than 50 NTU, and the conductivity is less than 50 μS / cm.

[0064] Without being bound by any theory, the inventors of this application speculate that the reaction mechanism of the above process is as follows. In step 2), the mixed solution is strongly acidic, with a pH of approximately 0.1. In step 3), the carrier, after deep vacuum degassing, has the largest specific surface area, allowing the ZrOCl2 solution to quickly enter the micropores of the carrier and be uniformly loaded onto the carrier with a high specific surface area, forming highly dispersed ZrOCl2 microcrystals during the drying process. In the reaction of step 5), a solution of ATMPA and sodium metasilicate is added dropwise to the dried intermediate material. While the aqueous solution is rapidly adsorbed by the solid material, the ZrOCl2 microcrystals loaded on the carrier dissolve and quickly react with ATMPA to form Zr-ATMP precipitate. Simultaneously, under the strong acid catalysis of the ZrOCl2 solution, metasilicate rapidly hydrolyzes to form a SiO2 film, which coats the outer layer of Zr-ATMP. This not only enhances the binding force between Zr-ATMP and the carrier but also blocks the growth of Zr-ATMP particles themselves, which is beneficial for forming amorphous or microcrystalline Zr-ATMP particles.

[0065] The inventors of this application were surprised to discover that the carrier-supported silicon-zirconium composite adsorbent prepared according to the method of the present invention has excellent adsorption performance for a large number of ions, including but not limited to Sr. 2+ Ba 2+ Co 2+ Uranyl ion (UO2) 2+ )Nd3+ Mg 2+ Ca 2+ Mn 2+ Cs + 、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ (where Am) 3+ (Representing minor actinides and other rare earth nuclides) has good adsorption properties.

[0066] As is well known, adsorbents generally exhibit high selectivity for only one type of ion. Therefore, when dealing with complex multi-nuclear waste liquids, a wide variety of adsorbents must be selected, resulting in highly complex adsorption systems for treating multi-nuclear waste liquids. However, the inventors of this invention have surprisingly discovered that the carrier-supported silicon-zirconium composite adsorbent prepared according to the method of this invention effectively removes Sr from multi-nuclear waste liquids such as spent fuel reprocessing and nuclear facility decommissioning waste liquids. 2+ Co 2+ Am 3+ and UO2 2 It features selective synchronization, thus enabling the simultaneous adsorption of Sr from multi-nucleoside wastewater. 2+ Co 2+ Am 3+ and UO2 2+ This was something that would have been difficult to anticipate before this application.

[0067] Furthermore, the inventors of this invention were surprised to discover that the carrier-supported silicon-zirconium composite adsorbent according to the present invention does not interfere with each other when combined with conventional cesium adsorbents. Therefore, when the carrier-supported silicon-zirconium composite adsorbent according to the present invention is combined with conventional cesium adsorbents (as is well known, conventional cesium adsorbents are effective against Cs in wastewater), the adsorbent does not interfere with each other. + and Rb + When combined, these adsorbents (possessing excellent adsorption properties) can effectively remove Sr from multi-nucleoside wastewater. 2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + and Rb + The adsorption and removal of polynuclear wastewater greatly simplifies the adsorption treatment device. In other words, the inventors of this invention have created a well-functioning adsorption device suitable for treating polynuclear wastewater, such as spent fuel reprocessing and nuclear facility decommissioning wastewater, using only a combination of two adsorbents—an added benefit.

[0068] Therefore, another aspect of the present invention provides a carrier-supported silicon-zirconium composite adsorbent according to the present invention, or a carrier-supported silicon-zirconium composite adsorbent prepared by the method according to the present invention, for adsorbing Sr. 2+ Ba 2+ Co 2+ UO2 2+ 、Nd 3+ Mg 2+ Ca 2+ Mn 2+ Cs + 、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ Its uses.

[0069] Another aspect of the present invention provides the above-mentioned carrier-supported silicon-zirconium composite adsorbent or the carrier-supported silicon-zirconium composite adsorbent prepared by the above method for simultaneously adsorbing and removing Sr from multi-nucleoside waste liquid. 2+ Co 2+ Am 3 + and uranyl ions (UO2) 2+ The uses of ).

[0070] Another aspect of the present invention provides the above-mentioned carrier-supported silicon-zirconium composite adsorbent, or a combination of the above-mentioned carrier-supported silicon-zirconium composite adsorbent prepared by the above method and a cesium adsorbent, for simultaneously adsorbing and removing Sr from multi-nucleon waste liquid. 2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + and Rb + Its uses.

[0071] Example

[0072] The disclosure of this invention is described in more detail through the examples below. These examples are merely illustrative and are not limited to these specific examples. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight, and all reagents used in the examples are commercially available and ready for use without further processing.

[0073] Example 1 Laboratory size

[0074] Add 12.75 g of zirconium oxychloride octahydrate to 10 mL of water and stir until completely dissolved. Add 10 g of vacuum-dried silica gel carrier to the resulting zirconium oxychloride solution under 0.1 atm. The carrier particles, pre-selected with a diameter of 0.3–1.2 mm, are dried at 110 °C under 0.1 atm for 24 h. After impregnation at room temperature for 2–4 h, the carrier particles are evaporated in a water bath to ensure uniform loading of zirconium oxychloride onto the carrier.

[0075] 10 mL of water was added to a hydrothermal reactor, followed by a certain amount of sodium metasilicate. After complete dissolution, a certain amount of ATMPA solid material was added and stirred until completely dissolved. The zirconium oxychloride particles prepared above were added to the mixed solution, stirred until uniform adsorption, and then allowed to stand at room temperature for 2 hours. The system was then sealed and reacted at 100°C under hydrothermal conditions for 10–48 hours. The obtained adsorbent particles were washed with pure water until the pH was neutral and the conductivity was less than 50 μS / cm. The particles were then dried to obtain the target adsorbent Zr-ATMP-Si.

[0076] Example 2 Industrial scale

[0077] The silica gel carrier is first sieved with a 0.3mm sieve, and 100kg of large particles are placed in a double cone reactor. It is heated to 80-90℃ under a vacuum of 0.01atm and dried for 20h. Then it is cooled to room temperature while maintaining a vacuum.

[0078] Add 100L of pure water to a vertical reactor, then add 120kg of zirconium oxychloride and stir until completely dissolved.

[0079] The zirconium oxychloride solution is injected into the reactor using a pump designed for a double cone reactor. The reactor is rotated continuously during injection to ensure uniform mixing of the solid and liquid phases.

[0080] A 0.1M NaOH solution was injected into the slurry film absorption tower connected to the double-cone reactor. After the absorption tower was turned on and running normally, the heating and vacuum systems of the double-cone reactor were turned on. The acidic vapors volatilized during the material drying process were absorbed by the falling film absorption tower. This stage yielded the dried intermediate Zr / support.

[0081] Add 150L of pure water to a vertical reactor, then add 15kg of sodium metasilicate. After it is completely dissolved, add 120kg of ATMPA and stir until it is completely dissolved.

[0082] The dried intermediate Zr / support was added to a vertical reactor, the reactor was sealed, and the mixture was heated to 90-100℃ under continuous stirring for 10-24 hours.

[0083] After cooling, the reactants are separated into solid and liquid phases by a centrifuge below the reactor to obtain crude Zr-ATMPA-Si adsorbent. The crude adsorbent is then dried in a forced-air drying oven and sieved, preferably with a particle size of 0.3-1.2 mm.

[0084] The particulate adsorbent is loaded into the cleaning column and cleaned with a cleaning device equipped with an RO membrane treatment system until the pH is neutral and the conductivity is less than 50 μS / cm. The obtained product is dried and stored.

[0085] The obtained target adsorbent was subjected to XRD analysis, and adsorption-desorption pore analysis was performed using a BJH pore size distribution analyzer (i.e., a nitrogen adsorption-desorption analyzer). Figure 1 The XRD patterns of the samples provided show that the adsorbent Zr-ATMP-Si / support synthesized by this method forms a microcrystalline state with an amorphous structure and exhibits high dispersibility. Figure 2 As shown, the adsorbent has a microporous structure, a weak hysteresis loop, a pore size of 2.73 nm, a pore volume of 0.155 mL / g, and a large specific surface area of ​​123.3 m². 2 / g.

[0086] Comparative Example 1 :

[0087] Comparative Example 1 describes the preparation of Zr-ATMP powder material using the method disclosed in CN102675364. According to CN102675364, the HF acid complexation method is employed, firstly adding HF acid to a zirconium oxychloride solution to form ZrF6. 2- Ions were then added dropwise to the mixed solution at room temperature, resulting in a white precipitate. The precipitate was transferred to a hydrothermal reactor and reacted at 90-100°C to obtain a white powder. The powder was then washed with pure water and ultrafiltration until the pH was neutral.

[0088] The obtained target adsorbent was subjected to XRD analysis, and the adsorption-desorption pores were analyzed using a BJH pore size distribution analyzer (i.e., a nitrogen adsorption-desorption analyzer). Figure 3 The XRD results of the powder sample are given. Its diffraction peaks are consistent with those of the sample given in CN102675364. It has sharp diffraction peaks, which indicates that the obtained Zr-ATMP powder has good crystallinity. There are small-angle diffraction peaks at 2θ < 5° that could not be detected completely, suggesting that the material has a mesoporous structure. Figure 4 The pore structure analysis results of this material are presented. Figure 4In the BJH adsorption-desorption curve, the hysteresis loop is clearly visible, proving that the material has a distinct mesoporous structure. Pore testing results show that the material contains both pores with diameters of 3.7 nm and 18.6 nm, with a pore volume of 0.306 cm³. 3 / g, with a specific surface area of ​​68.6m². 2 / g.

[0089] Example 3 ZrP-Si / SiO2 type adsorbent for Sr 2+ Co 2+ and Nd 3+ Static adsorption isotherm of ions

[0090] The static shake-flask cold test method was used to determine the adsorption isotherms of several typical nuclide ions for the particulate adsorbent ZrP-Si / SiO2. Sr-90 is a major nuclide found in various radioactive waste liquids, while Co-58 and Co-60 are common nuclides found in nuclear power plant and isotope production waste liquids. Nd2+ was used in the experiment. 3+ Representing nuclides with similar properties, such as Am 3+ Cm 3+ And rare earth metal nuclides such as Y 3+ wait.

[0091] Figure 5 This demonstrates the effect of ZrP-Si / SiO2 type adsorbents on Sr 2+ Co 2+ and Nd 3+ The static adsorption isotherm of ions. (From...) Figure 5 As shown by the isotherms, the particulate adsorbent ZrP-Si / SiO2 exhibits excellent adsorption performance for the aforementioned ions, Co. 2+ 、Nd 3+ and Sr 2+ The adsorption capacities were 1.6 meq / g, 1.2 meq / g, and 1.1 meq / g, respectively.

[0092] Example 4 Competitive adsorption performance of ZrP-Si / SiO2 type adsorbents for multiple ions

[0093] Static experimental methods were used to determine the concentrations of metal ions M and Sr in equivalent amounts. 2+ The selectivity coefficient of particulate adsorbent ZrP-Si / SiO2 for Sr under coexisting conditions.

[0094] Figure 6 The competitive adsorption performance of ZrP-Si / SiO2 type adsorbents for multiple ions is shown, where the ordinate logSx represents the logarithm of the selectivity coefficient Sx-Sr / M for Sr relative to other ions. Figure 6The experimental results show that the selectivity coefficients of the adsorbent for Sr and other competing ions follow the following rules: 1) When the ion concentration is equivalent to Sr, the selectivity order of ZrP-Si / SiO2 for Mg, Ca, Sr, and Ba is: Sr>Ba>Mg>Ca; 2) Compared with other +2 valence transition metals, the preferential adsorption order of ZrP for Sr is: Co>Sr>Mn>>Fe(2+); 3) Compared with other ions, the preferential adsorption order of Sr on ZrP is: Co>Sr>Ba>Ca>Mg>Nd>Cs~Rb>Fe(2+)>>Fe(3+)>Ce(4+).

[0095] Example 5 Adsorption isotherms of uranyl ions by ZrP-Si / SiO2 type adsorbent

[0096] A static experimental method was used to determine the effect of ZrP-Si / SiO2 type adsorbent on uranyl ions (UO2) in pure water and 1 g / L ammonium nitrate solution. 2+ The adsorption isotherm was determined. As a control, the adsorption isotherm of uranyl ions (UO2) on the silica gel support used in the preparation of the above-mentioned ZrP-Si / SiO2 type adsorbent was also measured in pure water and 1 g / L ammonium nitrate solution. 2+ Adsorption isotherms.

[0097] Figure 7 The adsorption isotherms for uranyl ions by ZrP-Si / SiO2 type adsorbents and corresponding silica supports are shown. Figure 7 The results show that the ZrP-Si / SiO2 type adsorbent has an adsorption capacity of nearly 180 mg / g for uranyl ions in pure aqueous solution and an adsorption capacity of more than 120 mg / g in 1 g / L ammonium nitrate solution.

[0098] As can be seen from the results of Examples 3-5 above, the carrier-supported silicon-zirconium composite adsorbent prepared according to the method of the present invention is effective against a variety of ions, especially Sr. 2+ Ba 2+ Co 2+ Uranyl ion (UO2) 2+ )Nd 3+ Mg 2+ Ca 2+ Mn 2+ Cs + 、Rb + Fe 2 + Fe 3+ Ce 3+ Am 3+ (where Am) 3+ (Representing minor actinides and other rare earth nuclides) has good adsorption properties.

[0099] Example 6 Dynamic adsorption performance of ZrP-Si / SiO2 type adsorbents for various ions

[0100] A fixed-bed adsorption reactor was used to determine the effect of ZrP-Si / SiO2 adsorbent on Sr. 2+ Co 2+ and Nd 3+ Dynamic adsorption performance. Adsorption column structural parameters: adsorbent volume 100 mL, adsorption column diameter 3 cm; solution composition: sodium nitrate solution with trace amounts of Sr. 2+ C0 2+ and Nd 3+ The sodium nitrate concentration was 1 g / L, the metal ion concentration was 0.57 mmol / L, and the water flow rate was 20 BV / h (2 L / h).

[0101] Figure 8 shows the dynamic adsorption performance of ZrP-Si / SiO2 type adsorbents for various ions, among which, Figure 8A It is a dynamic adsorption diagram for Nd ions; Figure 8B It is a dynamic adsorption diagram for Sr ions; Figure 8C This is a dynamic adsorption diagram for Co ions. In the above... Figures 8A-8C In the figure, the vertical axis represents the logarithm of the decontamination factor DF, logDF, where DF = C0 / Ce, and C0 and Ce are the concentrations of metal ions in the raw water and effluent, respectively. As shown in Figure 8, the decontamination factor of the adsorption reactor is controlled at DF = 1000, i.e., logDF = 3, indicating that the purification factor of the waste liquid is 1000. Under the condition of a purification factor of 1000, the adsorbent exhibits excellent decontamination performance for the three ions, and for Sr... 2+ C0 2+ and Nd 3+ The treatment capacity of the waste liquid was greater than 5000 BV, meaning the concentration factor of the radioactive waste reached over 5000. In other words, the results in Figure 8 demonstrate that the carrier-supported silicon-zirconium composite adsorbent according to the present invention can simultaneously and effectively adsorb Sr, Co, and Nd ions.

[0102] In conventional waste liquid adsorption tests, considering that radioactive Am-241 ions are a dangerous ion that poses a significant threat to human health, stable rare earth ions such as Nd are often used as substitutes for Am-241 ions to verify the adsorption effect of the test adsorbent on Am-241 ions. In the experiment of Example 6 above, the carrier-supported silicon-zirconium composite adsorbent according to the present invention can simultaneously and effectively adsorb Sr, Co, and Nd ions, which also demonstrates that the carrier-supported silicon-zirconium composite adsorbent according to the present invention can simultaneously and effectively adsorb Sr, Co, and Am ions.

[0103] Furthermore, uranyl ions are radioactive nuclides, and long-term dynamic adsorption of uranyl ions cannot be supported in general experiments. Therefore, the results can be illustrated by static adsorption in a specialized thermochemical laboratory. As shown in the static experiment of Example 5 of this application, the carrier-supported silicon-zirconium composite adsorbent according to the present invention also exhibits good adsorption performance for uranyl ions.

[0104] The results of the above embodiments show that the carrier-supported silicon-zirconium composite adsorbent according to the present invention is effective for simultaneously adsorbing and removing Sr from multi-nucleoside waste liquid. 2+ Co 2+ Am 3+ and uranyl ions (UO2) 2+ ).

[0105] Exemplary but non-limiting implementations are as follows:

[0106] Implementation Method 1. A carrier-supported silicon-zirconium composite adsorbent, which is microcrystalline, wherein the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has essentially no sharp X-ray diffraction peaks.

[0107] Implementation Method 2. The carrier-supported silicon-zirconium composite adsorbent according to Implementation Method 1, wherein the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (WHM) in the range of 15° to 30°, preferably in the range of 18° to 29°.

[0108] Implementation Method 3. The carrier-supported silicon-zirconium composite adsorbent as described in Implementation Method 1 or 2, wherein the carrier-supported silicon-zirconium composite adsorbent comprises a silicon oxide coating.

[0109] Embodiment 4. The carrier-supported silicon-zirconium composite adsorbent as described in any one of Embodiments 1 to 3, wherein the carrier-supported silicon-zirconium composite adsorbent is a reaction product of an organophosphoric acid containing aminotrimethylphosphonic acid and zirconium oxychloride.

[0110] Embodiment 5. The carrier-supported silicon-zirconium composite adsorbent as described in any one of Embodiments 1 to 4, wherein the carrier of the carrier-supported silicon-zirconium composite adsorbent includes inorganic oxides, activated carbon or a combination thereof, preferably including silica gel, titanium dioxide, zirconium oxide, activated carbon or a combination thereof.

[0111] Embodiment 6. The carrier-supported silicon-zirconium composite adsorbent as described in any one of Embodiments 1 to 5, wherein the carrier-supported silicon-zirconium composite adsorbent has a particle size in the range of 0.3 to 1.2 mm.

[0112] Embodiment 7. The carrier-supported silicon-zirconium composite adsorbent as described in any one of Embodiments 1 to 6, wherein the pore size of the carrier-supported silicon-zirconium composite adsorbent is in the range of 2 nm to 3 nm.

[0113] Implementation Method 8. The carrier-supported silicon-zirconium composite adsorbent as described in any one of Implementation Methods 1 to 6, wherein the carrier-supported silicon-zirconium composite adsorbent has essentially no hysteresis loop.

[0114] Implementation Method 9. A method for preparing a carrier-supported silicon-zirconium composite adsorbent, the method comprising the following steps:

[0115] i) subject the carrier to vacuum degassing at 0.1 atmospheres or less;

[0116] ii) An aqueous solution of a zirconium source with a certain degree of acidity is injected into the support to achieve a solid-liquid equilibrium state, and then dried to obtain an intermediate loaded with the zirconium source; and

[0117] iii) The obtained intermediate is mixed with a mixed solution of organophosphoric acid and metasilicate, and the reaction is carried out under sealed conditions to form the carrier-supported silicon-zirconium composite adsorbent.

[0118] The obtained carrier-supported silicon-zirconium composite adsorbent is microcrystalline, and the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has essentially no sharp X-ray diffraction peaks. Preferably, the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (WHM) in the range of 15° to 30°, and more preferably, it has a WHM in the range of 18° to 29°.

[0119] Implementation 10. The method as described in Implementation 9, wherein the aqueous solution of the zirconium source has a pH value of 0.1 or lower.

[0120] Implementation Method 11. The method as described in Implementation Method 9, wherein the mass ratio of the zirconium source to the carrier is controlled within the range of 1:1 to 1:5.

[0121] Implementation Method 12. The method as described in Implementation Method 9, wherein step iii) is performed at a temperature of 100-120°C for a period of 20 hours or longer, preferably for a period of 24 hours or longer.

[0122] Implementation Method 13. The method as described in Implementation Method 9, wherein the concentration of the zirconium source aqueous solution is in the range of 30-50 wt%; and / or the concentration of the organophosphoric acid aqueous solution is in the range of 10-60 wt%; and / or the concentration of the metasilicate aqueous solution is in the range of 1-10 wt%.

[0123] Implementation Method 14. The method as described in Implementation Method 9, wherein the zirconium source is zirconium oxychloride; and / or the metasilicate includes sodium metasilicate, potassium metasilicate, or a combination thereof; and / or the organophosphoric acid includes aminotrimethylphosphonic acid.

[0124] Implementation Method 15. The method as described in Implementation Method 9, wherein the carrier comprises inorganic oxides, activated carbon, or a combination thereof, preferably comprising silica gel, titanium dioxide, zirconium oxide, activated carbon, or a combination thereof.

[0125] Implementation Method 16. A carrier-supported silicon-zirconium composite adsorbent prepared by any one of Implementation Methods 1-8 or by any one of Implementation Methods 9-15 is used to adsorb Sr. 2+ Ba 2+ Co 2+ UO2 2+ 、Nd 3+ Mg 2+ Ca 2+ Mn 2+ Cs + 、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ Its uses.

[0126] Implementation Method 17. A carrier-supported silicon-zirconium composite adsorbent prepared by any one of Implementation Methods 1-8 or by any one of Implementation Methods 9-15 is used to simultaneously adsorb and remove Sr from multi-nucleoside waste liquid. 2+ Co 2+ Am 3+ and uranyl ions (UO2) 2+ The uses of ).

[0127] Implementation Method 18. A combination of a carrier-supported silicon-zirconium composite adsorbent prepared by any one of Implementation Methods 1-8 or by any one of Implementation Methods 9-15 with a cesium adsorbent is used to simultaneously adsorb and remove Sr from multi-nucleon waste liquid. 2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + and Rb + Its uses.

[0128] Although the present invention has been described with reference to numerous embodiments and examples, it will be readily apparent to those skilled in the art that modifications can be made to the invention without departing from the principles disclosed in the foregoing description. For example, combining multiple features or preferred embodiments described herein without departing from the principles disclosed in the foregoing description should be understood as part of the scope of this description. Such modifications are considered to be included in the following claims unless expressly specified otherwise. Accordingly, the embodiments detailed herein are merely exemplary and not intended to limit the scope of the invention, which is the full scope of the appended claims and any and all equivalents.

Claims

1. A carrier-supported silicon-zirconium composite adsorbent, which is microcrystalline, wherein the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent contains essentially no sharp X-ray diffraction peaks. in, The carrier-supported silicon-zirconium composite adsorbent is a reaction product of an organophosphate containing aminotrimethylphosphonic acid and zirconium oxychloride. In this embodiment, the silicon in the carrier-supported silicon-zirconium composite adsorbent exists in the form of a silicon oxide coating; and The phrase "basically no sharp X-ray diffraction peaks" means that when the carrier-supported silicon-zirconium composite adsorbent is subjected to X-ray diffraction analysis, the obtained X-ray diffraction pattern does not contain any sharp peaks from the carrier-supported silicon-zirconium composite adsorbent, and the obtained diffraction peaks all have a full width at half maximum (FWHM) of at least 5° or greater.

2. The carrier-supported silicon-zirconium composite adsorbent according to claim 1, wherein, The X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (FWHM) in the range of 15º to 30º.

3. The carrier-supported silicon-zirconium composite adsorbent according to claim 1, wherein, The X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (FWHM) in the range of 18º to 29º.

4. The carrier-supported silicon-zirconium composite adsorbent as described in any one of claims 1 to 3, wherein, The carrier of the carrier-supported silicon-zirconium composite adsorbent includes inorganic oxides, activated carbon, or a combination thereof.

5. The carrier-supported silicon-zirconium composite adsorbent as described in any one of claims 1 to 3, wherein, The carrier of the carrier-supported silicon-zirconium composite adsorbent includes silica gel, titanium dioxide, zirconium oxide, activated carbon, or a combination thereof.

6. The carrier-supported silicon-zirconium composite adsorbent according to any one of claims 1 to 3, wherein, The carrier-supported silicon-zirconium composite adsorbent has a particle size in the range of 0.3 to 1.2 mm.

7. The carrier-supported silicon-zirconium composite adsorbent according to any one of claims 1 to 3, wherein, The pore size of the carrier-supported silicon-zirconium composite adsorbent is in the range of 2 nm to 3 nm.

8. The carrier-supported silicon-zirconium composite adsorbent as described in any one of claims 1 to 3, wherein, The carrier-supported silicon-zirconium composite adsorbent has virtually no hysteresis loop. "Visibly no hysteresis loop" means that when the carrier-supported silicon-zirconium composite adsorbent is tested for adsorption and desorption using a BJH pore size distribution analyzer via a nitrogen adsorption experiment, no significant hysteresis phenomenon is observed in the adsorption and desorption amounts.

9. A method for preparing a carrier-supported silicon-zirconium composite adsorbent, the method comprising the following steps: i) subject the carrier to vacuum degassing at 0.1 atmospheres or less; ii) An aqueous solution of a zirconium source with a certain degree of acidity is injected into the support to achieve a solid-liquid equilibrium state, and then dried to obtain an intermediate loaded with the zirconium source; and iii) The obtained intermediate is mixed with a mixed solution of organophosphoric acid and metasilicate, and the reaction is carried out under sealed conditions to form the carrier-supported silicon-zirconium composite adsorbent. in, The obtained carrier-supported silicon-zirconium composite adsorbent is microcrystalline, and the X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has basically no sharp X-ray diffraction peaks. The carrier-supported silicon-zirconium composite adsorbent is a reaction product of organic phosphoric acid containing aminotrimethylphosphonic acid and zirconium oxychloride. In this embodiment, the silicon in the carrier-supported silicon-zirconium composite adsorbent exists in the form of a silicon oxide coating; and The phrase "basically no sharp X-ray diffraction peaks" means that when the carrier-supported silicon-zirconium composite adsorbent is subjected to X-ray diffraction analysis, the obtained X-ray diffraction pattern does not contain any sharp peaks from the carrier-supported silicon-zirconium composite adsorbent, and the obtained diffraction peaks all have a full width at half maximum (FWHM) of at least 5° or greater.

10. The method of claim 9, wherein, The X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (FWHM) in the range of 15º to 30º.

11. The method of claim 9, wherein, The X-ray diffraction spectrum of the carrier-supported silicon-zirconium composite adsorbent has a full width at half maximum (FWHM) in the range of 18º to 29º.

12. The method of claim 9, wherein, The aqueous solution of the zirconium source has a pH value of 0.1 or lower.

13. The method of claim 9, wherein, The mass ratio of the zirconium source to the carrier is controlled within the range of 1:1 to 1:

5.

14. The method of claim 9, wherein, Step iii) involves reacting at a temperature of 100-120°C for 20 hours or longer.

15. The method of claim 9, wherein, Step iii) involves reacting at a temperature of 100-120°C for 24 hours or longer.

16. The method of claim 9, wherein, The concentration of the zirconium source aqueous solution is in the range of 30-50 wt%; and / or the concentration of the organophosphoric acid aqueous solution is in the range of 10-60 wt%; and / or the concentration of the metasilicate aqueous solution is in the range of 1-10 wt%.

17. The method of claim 9, wherein, The zirconium source is zirconium oxychloride; and / or the metasilicate includes sodium metasilicate, potassium metasilicate, or a combination thereof; and / or the organophosphoric acid includes aminotrimethylphosphonic acid.

18. The method of claim 9, wherein, The carrier includes inorganic oxides, activated carbon, or a combination thereof.

19. The method of claim 9, wherein, The carrier includes silica gel, titanium dioxide, zirconium oxide, activated carbon, or a combination thereof.

20. The carrier-supported silicon-zirconium composite adsorbent according to any one of claims 1-8 or the carrier-supported silicon-zirconium composite adsorbent prepared by the method according to any one of claims 9-19 is used for adsorbing Sr. 2+ Ba 2+ Co 2+ UO2 2+ 、Nd 3+ Mg 2+ Ca 2+ Mn 2+ Cs + 、Rb + Fe 2+ Fe 3+ Ce 3+ Am 3+ Its uses.

21. The carrier-supported silicon-zirconium composite adsorbent according to any one of claims 1-8 or the carrier-supported silicon-zirconium composite adsorbent prepared by the method according to any one of claims 9-19 is used to simultaneously adsorb and remove Sr from multi-nucleoside waste liquid. 2+ Co 2+ Am 3+ and uranyl ions (UO2) 2+ The uses of ).

22. A combination of the carrier-supported silicon-zirconium composite adsorbent according to any one of claims 1-8 or the carrier-supported silicon-zirconium composite adsorbent prepared by the method according to any one of claims 9-19 and a cesium adsorbent, used for simultaneously adsorbing and removing Sr from multi-nucleoside waste liquid. 2+ Co 2+ Am 3+ Uranyl ion (UO2) 2+ ), Cs + and Rb + Its uses.

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