CN112760659B - Oxidation decontamination gel and preparation method and application thereof - Google Patents
Oxidation decontamination gel and preparation method and application thereof Download PDFInfo
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Abstract
The invention belongs to the technical field of radioactive decontamination, and relates to an oxidation decontamination gel, and a preparation method and application thereof. The oxidation decontamination gel comprises the following components in percentage by weight: 5-15% of gel base material as gel framework material, 5-10% of surfactant, 0.5-5% of thixotropic multiplying agent, 3-20% of strong oxidant, 3-20% of acid, 1-5% of modifier and 25-82.5% of water. The oxidation decontamination gel and the preparation method and application thereof can be used for better preparing the oxidation decontamination gel, the prepared oxidation decontamination gel is the oxidation gel for second-generation radioactive contamination metal decontamination, water washing is not needed after decontamination, the residual oxidation decontamination gel can be automatically dried and cracked, and a brush is convenient to clean, or a dust collector is adopted for suction collection, so that liquid secondary waste is not generated in decontamination, and the oxidation decontamination gel is more suitable for on-site decontamination.
Description
Technical Field
The invention belongs to the technical field of radioactive decontamination, and relates to an oxidation decontamination gel, and a preparation method and application thereof.
Background
The nuclear industry in China has developed over decades to produce a huge amount of radioactively contaminated metals. The radioactive contamination metal is decontaminated deeply, the surface contamination level is reduced, the pollution metal amount is reduced, and meanwhile, the radiation staff can be protected and are irradiated less.
Since the oxidizing substance has a corrosive action on the metal, in the field of radioactive decontamination, the metal surface can be corroded by the strong oxidizing substance, so that the radioactive substance can be removed. Oxidizing substances commonly used for this purpose include higher silver ions, higher cerium ions, and higher cobalt ions.
The common oxidative decontamination means is to mix high valence state ions with acid, take liquid acid as a carrier, and adopt means such as spraying and soaking to decontaminate metals. However, liquid decontamination produces more secondary liquid waste.
The gel is a non-Newtonian fluid with good thixotropy, the apparent viscosity of the gel is reduced under the action of a shearing force, and the apparent viscosity is rapidly increased after the shearing force is removed. Furthermore, the above properties of the inorganic gel are not deteriorated by strong acid, strong base and strong oxidizing agent.
The first generation of oxidation gel for decontaminating radioactive contaminated metals introduces a mixture of a strong oxidant and an acid into the inorganic gel, and can combine the corrosion performance of the strong oxidant to the metals with the excellent rheological property of the inorganic gel to form the oxidation decontamination gel. The oxidized decontamination gel can be sprayed or brushed on the surface of the metal to be decontaminated, and the residual oxidized decontamination gel can be collected only by washing with a small amount of water after decontamination is finished, so that the quantity of secondary waste liquid is greatly reduced.
Disclosure of Invention
The invention aims to provide an oxidation decontamination gel for decontamination of second-generation radioactive contaminated metals, which can automatically dry and crack without washing with water after decontamination is finished, and is convenient to clean with a brush or collected by suction of a dust collector, so that liquid secondary waste is not generated in decontamination, and the oxidation decontamination gel is more suitable for on-site decontamination.
To achieve this object, in a basic embodiment, the present invention provides an oxidative stain removal gel comprising, in weight percent: 5-15% of gel base material as gel framework material, 5-10% of surfactant, 0.5-5% of thixotropic multiplying agent, 3-20% of strong oxidant, 3-20% of acid, 1-5% of modifier and 25-82.5% of water.
The relevant principle of the invention is as follows:
the oxidation decontamination gel takes inorganic gel as a carrier and takes a strong oxidizer as an effective corrosion decontamination substance. The oxidation decontamination gel can be coated on the metal surface by a spraying or brushing way, the thixotropy of the gel carrier ensures that the gel carrier can not flow on the vertical surface and the top surface, and the strong oxidant in the gel carrier reacts with the metal to corrode and dissolve the metal material and the radionuclide on the surface or the shallow layer thereof into the oxidation decontamination gel together, and the metal material and the radionuclide are collected after being dried to finish decontamination.
The research and screening process of the invention is as follows.
(I) preliminary selection results of gel modification materials
1. Drying the gel
The oxidation decontamination gel researched by the invention is a gel formed by taking fumed silica as a framework, and the drying process can be divided into three drying stages according to the gel drying theory, namely a constant-speed drying stage, a first deceleration drying stage and a second deceleration drying stage in sequence, as shown in figure 1.
The constant-speed drying stage is mainly characterized in that free water in a gel skeleton network is evaporated, the correlation with the internal structure, capillary tension and the like of the gel is not large, and the evaporation rate is similar to pure water volatilization, so that the evaporation rate at the stage is almost the same.
As the water in the gel evaporates, the volume of the gel shrinks; as the liquid evaporates, a large meniscus forms in the gel well, and capillary action presses the particles together, as shown in fig. 2.
The capillary contraction action extrudes the particles to compress the aperture of the liquid phase channel in the gel hole, and the action can cause the liquid phase channel to be reduced and the mass transfer resistance to be increased when the liquid phase in the pore channel is extruded out of the pore channel, and the liquid phase is bound in smaller pores, so that the drying speed of the first deceleration drying stage and the second deceleration drying stage is greatly reduced.
According to the above drying process and microscopic analysis, the drying rate of the oxidized decontamination gel is increased mainly by increasing the drying rate of the two subsequent drying stages, possibly by two methods.
The first is that fumed silica with proper pore diameter (specific surface area) is adopted as a gel thixotropic agent, the mode of increasing large-particle-diameter silica is adopted to improve the framework structure, and the proportion of large capillary pores is increased, so that the drying performance is improved.
Secondly, particles with a certain particle size are added in the gel drying process, so that the particles can be used as the pivot of a gel network in the gel drying process, the network gaps are uniform, the strength of the gel skeleton can be increased, the capillary force effect can be better resisted, the phenomenon that the pore passages of the gel network are extruded and closed too early under the action of the capillary force in the drying process is avoided, and the drying period is shortened.
According to the analysis, in order to improve the drying speed of the oxidation decontamination gel, the resistance of the microstructure to the movement and diffusion of water molecules can be reduced by enhancing the skeleton structure of the gel, so that the drying energy consumption is reduced, and the drying is accelerated.
2. Theory of adhesion
Bonding refers to the joining of surfaces of homogeneous or heterogeneous objects together with an adhesive, and the generation of adhesive force includes physical, chemical and mechanical actions between the adhesive and the adherend.
As can be seen from the existing micrographs of the stainless steel surface before and after corrosion, the surface of the stainless steel surface before corrosion is uniform in appearance, and the crystal grain gaps are smaller; after the corrosion of the oxidized decontamination gel, the grain gaps are obviously enlarged, and the depth is deepened compared with the depth before the corrosion. Therefore, it is supposed that the adhesion between the oxidized decontamination gel and the metal substrate after decontamination and drying is mainly mechanical adhesion, and the essence thereof is that the silica skeleton structure penetrates into the gaps of the grooves on the surface of the substrate to form hooking or embedding, so as to form adhesion, and the gel after drying is difficult to peel off from the decontamination surface.
In the process of the oxidation decontamination gel decontamination, the framework structure-wrapped aqueous decontaminating agent is in full contact with the surface of the base material, so that the surface of the base material is oxidized and dissolved and separated from the base material, and the better decontamination can be realized. In order to realize better infiltration and contact of the oxidation decontamination gel to a base material in a wet state and easy stripping in a dry state, the available method only reduces the size of a crack fragment generated by the oxidation decontamination gel in the drying process, thereby reducing the mechanical bonding force between the crack xerogel fragment and the base material, and being easier to strip the gel from a decontamination surface more completely.
3. Preliminary selection and result analysis of modified materials
(1) Preliminary selection results
From the analysis results and the selection principle of the modified material, the idea is to add inorganic fibers or other inorganic layered substances into the oxidation decontamination gel, and the modified material is expected to support the silica framework material in the gel system to improve the drying speed, and assist the oxidation decontamination gel to agglomerate and be easy to strip after drying.
Selecting 100-mesh, 800-mesh and 1500-mesh glass fibers with different scales, 1500-mesh kaolin and precipitated barium sulfate as modified materials, respectively using 1%, 3% and 5% of the weight of the oxidized decontamination gel as additive amounts, drying for 72h in a constant temperature and humidity chamber at the temperature of 30 ℃ and the humidity of 50%, collecting by using a soft brush after drying, and primarily selecting the modified materials according to the drying and collecting conditions. Table 1 is the case of the preliminary selection test, wherein the basic formulation of the oxidizing decontamination gel is: the gel base material of the lithium magnesium silicate accounts for 9 percent of the mass percent of the modified oxidation decontamination gel; surfactant AT904, accounting for 5% by mass of the modified oxidation decontamination gel; the thixotropic multiplying agent Y1010 accounts for 1 percent of the mass percent of the modified oxidation decontamination gel; the strong oxidant ammonium cerium nitrate accounts for 12 percent of the modified oxidation decontamination gel by mass percent; and the nitric acid accounts for 15 percent of the mass percent of the modified oxidation decontamination gel.
TABLE 1 Primary selection test drying and stripping conditions of modified oxidized soil release gel
From the results in table 1, the oxidative soil release gels of each formulation were completely dried. In all of the initially selected formulations, the best peel was achieved with 1% glass fiber (1500 mesh) and 3% kaolin (1500 mesh), and further validation tests were performed using both formulations.
(2) Drying Performance test
The formulations with 1% glass fiber (1500 mesh) and 3% kaolin (1500 mesh) added and the original formulation oxidized soil release gel were used for drying performance tests, and the cumulative water loss rate during drying was plotted at 30 ℃ and 50% humidity, and the results are shown in FIG. 3.
As can be seen from the graph of the change of the drying time and the cumulative water loss rate in FIG. 3, the drying speed and the final drying degree of the oxidized decontamination gel are improved to a certain extent after the modified material is added. Starting to dry for about 5 hours, namely a constant-speed drying stage, wherein the drying speed of the stage is basically the same; about 5 hours to about 25 hours is a slow drying stage followed by a slow drying stage, which substantially coincides with the three stages of the gel drying process described previously.
After the first reduced speed drying stage, water in a free state, which is partially bound by the network, still exists in the gel network. Compared with the original formula, the formula added with the modified material has the advantages that the drying speed of the formula added with 1% of glass fiber (1500 meshes) is basically the same as that of the original formula, and the addition amount is possibly too small, so that the network structure in the oxidation decontamination gel cannot be effectively supported; the formulation added with 3% kaolin (1500 mesh) has a faster drying speed, and probably the gel network effectively resists the extrusion of capillary force generated by water evaporation to the pore canal of the gel network under the supporting action of dispersed kaolin particles, so that the water evaporation channel can be well maintained. From the drying chart, the glass fiber modified oxidized detersive gel is mainly used for improving the drying speed of the second deceleration drying stage, and the kaolin modified oxidized detersive gel plays a role in promoting drying in the first and second deceleration drying stages.
(3) Analysis of results
Particles with high aspect ratios tend to agglomerate in a packed manner within the dispersion, creating more interstitial spaces, as shown in figure 4 below.
The kaolin and the glass fiber powder are materials with high length-diameter ratio, the length-diameter ratio of the materials is 5-20, and the length-diameter ratio is respectively shown in figures 5 and 6. The added modified material changes the network structure of the silica gel system to a certain extent, the supporting effect generated by the mutual accumulation of the modified material effectively resists the extrusion of capillary force generated by evaporation on silica particles, gaps generated by the accumulation of the particles better keep a channel for the solvent to evaporate and rise, the smoothness of a silica pore channel is kept, the drying speed is accelerated, and the drying degree is increased.
As can be seen from FIG. 7 of the dried test piece, the staged cracking phenomenon is more obvious when the original formula oxidized decontamination gel is cracked by drying (FIG. 7, left), and longer and wide cracks and shorter and thinner cracks can be seen in the picture, which is more consistent with the standard staged cracking phenomenon. Longer and wider cracks are formed in the early stage of drying, shorter and finer cracks are formed in the later stage of drying, and the cracks are narrow and short because part of the stress is released after the early cracks are formed and the stress of the later cracks is limited. Therefore, the overall dimension of the split block is larger, and the split block is firmly bonded with the base material.
The phenomena of drying and grading cracking of the oxidized decontamination gel added with the glass fiber (in figure 7) and the oxidized decontamination gel added with the kaolin (on the right side of figure 7) are not obvious, the dried gel is uniformly cracked into smaller and shorter cracks, and the number of the cracks is more than that of the original oxidized decontamination gel, so that more solvent volatilization channels are formed, which can also show that after the modified material is added, the drying speed is higher than that of the original oxidized decontamination gel, and the boundary of two deceleration drying stages is not obvious. After the oxidative decontamination gel cracks into smaller pieces, the mechanical adhesion between each piece and the substrate is reduced and the pieces are more easily peeled off.
(II) thixotropic Performance test of improved Oxidation decontamination gel
The results of the gel thixotropy test are shown in Table 2. Wherein, the basic formula of the oxidation decontamination gel is as follows: the gel base material of the lithium magnesium silicate accounts for 9 percent of the mass percent of the modified oxidation decontamination gel; surfactant AT904, accounting for 5% by mass of the modified oxidation decontamination gel; the thixotropic multiplying agent Y1010 accounts for 1 percent of the modified oxidation decontamination gel by mass percent; the strong oxidant ammonium cerium nitrate accounts for 12 percent of the modified oxidation decontamination gel by mass percent; the nitric acid accounts for 15 percent of the modified oxidation decontamination gel by mass percent.
TABLE 2 rheological test results for oxidized stain removal gels and modified oxidized stain removal gels
The thixotropy can directly reflect the sensitivity of the thixotropy of the object. The higher the thixotropic energy, the more sensitive the thixotropy of the object and the more susceptible the morphological transformation occurs under the influence of the shearing action. The viscosity of the oxidized decontamination gel after the kaolin modification is basically not changed, and the thixotropic energy is reduced to a certain extent; the viscosity and thixotropic energy of the glass fiber modified oxidized decontamination gel are greatly reduced, and the spraying performance is supposed to be reduced.
As shown in fig. 8, the viscosity profile of the kaolin modified oxidized soil removal gel, although thixotropic energy is lost, can recover viscosity in a shorter time after shearing is removed, has the same type of viscosity profile as the original oxidized soil removal gel, and does not change the original rheological behavior of the gel. Through actual spraying construction, the oxidation decontamination gel modified by adding 3% of kaolin (1500 meshes) can meet the requirement of spraying wall hanging, and the oxidation decontamination gel modified by adding 1% of glass fiber (1500 meshes) has sagging phenomenon, as shown in figure 8.
(III) modified oxidation decontamination gel decontamination simulation test research
From the test results, the modified oxidized decontamination gel with the addition amount of 3% of kaolin (1500 meshes) is selected to carry out a simulated decontamination test, and the corrosion performance and the stripping performance of the gel are verified.
1. Corrosion performance test
The prepared oxidation decontamination gel is coated on a 06Cr19Ni10 stainless steel plate by a film coater, and 4 parallel samples are selected. The reaction conditions at 0h, 2h and 24h were analyzed as follows.
From the photographs of the oxidized decontamination gel coated on the steel plates for 0h and 2h, it can be seen that the color of the oxidized decontamination gel changes from orange to colorless when the oxidized decontamination gel is acted on the steel plates for 2h under the drying condition that the relative humidity is 50% and the temperature is 30 ℃, which indicates that the reaction of Ce (IV) in the oxidized decontamination gel and the steel plates is basically finished. Upon drying at this temperature and humidity for 24 hours, the drying of the oxidized detersive gel layer is substantially complete, forming a dry oxidized detersive gel layer having a plurality of cracks. The light brush is stripped by a soft brush, the edge part forms stronger adhesive force with the base material because the coating formed after drying is too thin, and the soft brush is difficult to strip; the xerogel in the middle part can be basically stripped after being brushed off once.
The gel dosage, coating area, steel plate weight loss and corrosion thickness in the oxidation decontamination gel simulated decontamination test are shown in table 3 below.
TABLE 3 Corrosion of stainless steel sheet with modified oxidative decontamination gel
(06Cr19Ni10 stainless steel density according to 7.93g/cm 3 Meter)
From the results in Table 3, it can be seen that the amount of modified oxidized soil release gel used is about 0.05g/cm 2 I.e. 0.5kg/m 2 The thickness of the corrosion to the 06Cr19Ni10 stainless steel plate can reach 0.6-0.7 μm, which is equivalent to the thickness of the corrosion to the stainless steel by the original oxidation decontamination gel, and shows that the oxidation decontamination gel with the improved formula has no significant difference in the corrosion capability to the stainless steel from the original formula.
2. Dry collected results of elemental analysis of modified oxidized decontamination gel
In the glue analysis, when the ED-XRF (energy dispersive fluorescence spectrometer) method is adopted for analysis, K for semi-quantitative analysis of Fe element α Angle of spectral line diffraction peak and L of Ce element α Diffraction peak angles of spectral lines are similar, and the spectral line of Fe element is covered by L of Ce element α The spectral lines are completely shielded and cannot be semi-quantitatively analyzed. Therefore, the analysis of the dry-oxidation decontamination gel can only be carried out by a WD-XRF (wavelength dispersive fluorescence spectrometer) method, the analysis pattern is shown in FIG. 9, and the calculation results of the element content are shown in Table 4.
TABLE 4 analysis result (wt%) of element content in oxidized decontaminating gel
From the analysis results, it is clear that the dry-oxidation decontamination gel after the action with the steel sheet contains elements such as Fe, Cr, Ni, and the like. The contents of the elements in the 06Cr19Ni10 stainless steel according to the GB/T2451-2017 specification are shown in the following table 5.
TABLE 506 elemental content (wt%) of Cr19Ni10
Wherein the ratio of Fe, Cr and Ni elements is 6.09: 1.82: 1-8.375: 2.25:1, the mass ratio of the three elements in the dry oxidation decontamination gel product is 8.1:1.8:1, and the mass ratio is close to the content ratio of the elements in the standard. Because the modified oxidation decontamination gel does not contain Fe, Cr and Ni elements in the production process, the analysis result shows that the corrosion product formed by the oxidation decontamination gel corroding the stainless steel surface layer enters the xerogel layer and is collected together with the dry oxidation decontamination gel.
3. Surface topography analysis of decontamination stainless steel sheet
The surface of the stainless steel plate is observed by a scanning electron microscope, and the microscopic morphologies of the modified oxidized decontamination gel before and after corrosion are analyzed, and the results are respectively shown in fig. 10 and fig. 11.
As can be seen from the SEM image of the stainless steel plate, before the oxidation decontamination gel is corroded, the surface of the stainless steel has striation lines generated in the processing process, has a certain depth (on the left of figure 10), and also has punctiform or blocky bulges or recesses (on the right of figure 10). After the corrosion of the modified oxidation decontamination gel, the stripe-shaped lines on the surface of the steel plate are not as clear as those on the original plate surface, the corrosion effect generates a grinding effect on the surface of the steel plate (fig. 11 left), and in a 200nm SEM picture, it can be seen that very dense honeycomb-shaped corrosion pits (fig. 11 right) are generated on the surface of the stainless steel plate, and the oxidation decontamination gel is shown to form obvious corrosion on the surface of the stainless steel plate.
In a preferred embodiment, the present invention provides an oxidative stain removal gel wherein:
the gel substrate is selected from one or more of magnesium lithium silicate, calcium oxide or silicon dioxide;
the surfactant is selected from CH 3 (CH 2 ) 5 (OCH 2 CH 2 ) 2 One or more combinations of OH, AT904, or alkyl diphenyl oxide disulfonate;
the thixotropic doubling agent is selected from one or more of Y1010 (Shanghai Yingjia development Co., Ltd.), T2-815 (Guangzhou Tengtang chemical industry Co., Ltd.) or hydrogenated castor oil.
In a preferred embodiment, the present invention provides an oxidative stain removal gel wherein the strong oxidizing agent is selected from one or more combinations of cobalt hexaammine trichloride, cerium ammonium nitrate or silver diammine chloride.
In a preferred embodiment, the present invention provides an oxidising decontamination gel, wherein the acid is selected from nitric acid and/or hydrochloric acid.
In a preferred embodiment, the present invention provides an oxidative decontamination gel, wherein the modifier is selected from one or more of kaolin, nano glass fibres, barium sulphate in combination.
In a preferred embodiment, the present invention provides an oxidative stain removal gel, wherein the oxidative stain removal gel further comprises 0.1-3% by weight of an antifoaming agent selected from the group consisting of XWC-7100 (SyncHexini Wan environmental protection technologies, Ltd.), n-octanol, and silicone emulsion in combination with one or more of these.
In a preferred embodiment, the present invention provides an oxidative stain removal gel wherein the oxidative stain removal gel further comprises from 0.1 to 0.5% by weight of a color indicator selected from one or more of methylene blue, sodium di-bentiaminate or ruthenium pyrimidinate.
In a preferred embodiment, the present invention provides an oxidative stain removal gel wherein the oxidative stain removal gel further comprises 0.1-2% by weight of a thickening agent selected from HK-315 (cantonese, guangzhou) and/or diethylene glycol monohexyl ether.
The second purpose of the invention is to provide a preparation method of the oxidation decontamination gel, which can be used for better preparing the oxidation decontamination gel, the prepared oxidation decontamination gel is the oxidation gel for second-generation radioactive contamination metal decontamination, water washing is not needed after decontamination, and the residual oxidation decontamination gel can be automatically dried and cracked, and is convenient to clean by a brush or collected by a suction cleaner, so that liquid secondary waste is not generated in decontamination, and the oxidation decontamination gel is more suitable for on-site decontamination.
To achieve this object, in a basic embodiment, the present invention provides a process for the preparation of the aforementioned oxidative soil release gel, said process comprising the steps of:
(1) adding the gel base material in the formula amount into the water in the formula amount, and fully stirring and emulsifying to be uniform;
(2) adding other components with the formula amount except the gel base material, the water, the surfactant and the thixotropic multiplying agent and uniformly mixing;
(3) the surfactant and the thixotropic multiplying agent with the formula amount are added and mixed evenly before use.
And (3) putting the prepared oxidized decontamination gel into a feeding hole of a spraying machine for construction operation, after the oxidized decontamination gel is coated to an area to be decontaminated, enabling the oxidized decontamination gel not to flow and hang, naturally drying for 4-10h, and collecting the oxidized decontamination gel by a dry method (brush cleaning or suction by a dust collector).
The third purpose of the invention is to provide the application of the oxidation decontamination gel for radioactive contamination metal decontamination, so that the residual oxidation decontamination gel can be automatically dried and cracked without being washed by water after decontamination is finished, and the cleaning is convenient by a brush or is collected by suction of a dust collector, so that liquid secondary waste is not generated in decontamination, and the oxidation decontamination gel is more suitable for on-site decontamination.
To achieve this object, in a basic embodiment, the present invention provides the use of the aforementioned oxidative decontamination gel for the decontamination of radioactively contaminated metals.
The invention has the beneficial effects that by utilizing the oxidized decontamination gel and the preparation method and application thereof, the oxidized decontamination gel can be better prepared, the prepared oxidized decontamination gel is the second-generation oxidized gel for radioactive contamination metal decontamination, water washing is not needed after decontamination, the residual oxidized decontamination gel can be automatically dried and cracked, and a brush is convenient to clean, or a dust collector is adopted for suction collection, so that liquid secondary waste is not generated in decontamination, and the oxidized decontamination gel is more suitable for on-site decontamination.
The oxidation decontamination gel disclosed by the invention is simple to prepare, convenient to apply and capable of being remotely coated and collected, and has the following beneficial effects:
(1) the method has high decontamination efficiency for radioactive metals, and has the same decontamination efficiency as corrosion decontamination of strong acid and strong oxidant.
(2) The decontamination process does not generate secondary waste liquid, and is particularly suitable for decontaminating places without liquid collection capacity.
(3) The decontamination depth is controllable: the depth of stain removal of the oxidized stain removal gel is related only to its amount and duration of action (see figure 12 for experimental data). As can be seen from FIG. 12, when the action time is sufficient, the decontamination depth and the gel dosage are basically in a linear relationship, and the controllability of the decontamination depth is ensured.
(4) The decontamination result is visual, and is convenient to distinguish: when the gel acts for about 2 hours, part of the gel has a color change phenomenon; after the gel is acted for 5-6h, the applied gel is completely discolored and loses efficacy, and the phenomenon can also be used for judging whether the gel decontamination is finished.
(5) Can be remotely operated: and by matching with corresponding spraying equipment and collecting equipment, the whole decontamination process can realize remote operation and can be used for radioactive metal decontamination work in environments with higher dosage rate.
Drawings
FIG. 1 is a schematic representation of the general drying stage of an aqueous dispersion (latex evaporation 3 stage as found by Vanderhoff et al).
Fig. 2 is a schematic diagram of capillary action during drying.
Fig. 3 is a graph of the cumulative water loss for an improved oxidized detersive gel.
FIG. 4 is a schematic diagram of high aspect ratio filler packing.
FIG. 5 is an SEM image of kaolin.
FIG. 6 is a SEM image of the glass fiber.
FIG. 7 is a graph of cracks after drying of the oxidized decontaminating gel.
Fig. 8 is a graph of the viscosity of the oxidized soil release gel and the kaolin modified oxidized soil release gel.
FIG. 9 is a WD-XRF pattern of the dry oxidation decontamination gel after interaction with a steel plate.
FIG. 10 is an SEM electron micrograph of a 06Cr19Ni10 stainless steel plate before corrosion.
FIG. 11 is an SEM electron micrograph of a 06Cr19Ni10 stainless steel plate after corrosion.
FIG. 12 is a graph of the amount of oxidizing decontamination gel used versus average corrosion thickness obtained in example 1.
Detailed Description
The following description will further explain embodiments of the present invention by referring to the examples and the accompanying drawings.
Example 1:
the formulation of the oxidized soil release gel prepared in this example was as follows:
14% of gel base material silicon dioxide, a surfactant AT 9048%, a thixotropic multiplying agent T2-8151%, a strong oxidant hexammoniated cobalt trichloride 8%, 9% of hydrochloric acid, 1% of modifier kaolin (purchased from Takara Kaolin Limited liability company in inner Mongolia), 1% of defoamer n-octanol, 0.5% of color indicator sodium di-aniline sulfonate and 57.5% of water.
The specific preparation method of the oxidation decontamination gel is as follows:
(1) adding the gel base material in the formula amount into the water in the formula amount, and fully stirring and emulsifying to be uniform;
(2) adding other components except the gel base material, water, surfactant and thixotropic multiplying agent according to the formula amount, uniformly mixing, and sealing for later use;
(3) the surfactant and the thixotropic multiplying agent with the formula amount are added and mixed evenly before use.
The oxidation decontamination gel prepared by the method is defoamed and then is coated on the surface of 304 stainless steel in a scraping way, and the action is carried out for 8 hours. The amount of the gel is variable, the gel is collected after being completely dried, and the corrosion depth of the stainless steel sample is measured by adopting a weight loss method. The field environmental conditions were 65% humidity and 10 ℃ temperature, and the results are shown in fig. 12.
As can be seen from fig. 12, under otherwise identical conditions, the thickness of the corrosion of the oxidized soil release gel was essentially linear with gel usage, a property that facilitates quantitative soil release.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations. The foregoing examples or embodiments are merely illustrative of the present invention, which may be embodied in other specific forms or in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the invention should be indicated by the appended claims, and any changes that are equivalent to the intent and scope of the claims should be construed to be included therein.
Claims (9)
1. An oxidative decontamination gel, characterized in that the oxidative decontamination gel comprises, by weight: 5-15% of gel base material as gel skeleton material, 5-10% of surfactant, 0.5-5% of thixotropic multiplying agent, 3-20% of strong oxidant, 3-20% of acid, 1-5% of modifier, 25-82.5% of water,
the gel substrate is selected from one or more of magnesium lithium silicate, calcium oxide or silicon dioxide;
the modifier is selected from one or more of kaolin, nano glass fiber and barium sulfate.
2. The oxidative decontamination gel of claim 1, wherein:
the surfactant is selected from CH 3 (CH 2 ) 5 (OCH 2 CH 2 ) 2 One or more combinations of OH, AT904, or alkyl diphenyl oxide disulfonate;
the thixotropic multiplying agent is one or a combination of Y1010, T2-815 or hydrogenated castor oil.
3. The oxidative decontamination gel of claim 1, wherein: the strong oxidant is selected from one or more of hexaammine cobalt trichloride, ammonium cerium nitrate or silver diammine chloride.
4. The oxidative decontamination gel of claim 1, wherein: the acid is selected from nitric acid and/or hydrochloric acid.
5. The oxidative decontamination gel of claim 1, wherein: the oxidation decontamination gel also contains 0.1-3% of defoaming agent by weight percentage, which is selected from one or more of XWC-7100, n-octanol or silicone emulsion.
6. The oxidative decontamination gel of claim 1, wherein: the oxidation decontamination gel also contains 0.1-0.5% of color indicator by weight percentage, which is selected from one or more of methylene blue, sodium di-aniline sulfonate or ruthenium pyrimidine.
7. The oxidative decontamination gel of claim 1, wherein: the oxidation decontamination gel also contains 0.1-2% of thickener selected from HK-315 and/or diethylene glycol monohexyl ether.
8. A method of preparing an oxidising decontamination gel according to any of claims 1-7, characterised in that the method of preparation comprises the steps of:
(1) adding the gel base material in the formula amount into the water in the formula amount, and fully stirring and emulsifying to be uniform;
(2) adding other components with formula amount except the gel base material, water, surfactant and thixotropic multiplying agent, and uniformly mixing;
(3) the surfactant and the thixotropic multiplying agent with the formula amount are added and mixed evenly before use.
9. Use of an oxidative decontamination gel according to any one of claims 1-7 for the decontamination of radioactively contaminated metals.
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| CN113481065A (en) * | 2021-06-18 | 2021-10-08 | 中国辐射防护研究院 | Foam gel and preparation method thereof |
| CN114672816B (en) * | 2022-01-07 | 2024-04-05 | 航天科工防御技术研究试验中心 | Composition for removing corrosion on aluminum alloy surface as well as preparation method and application thereof |
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| GB1435855A (en) * | 1973-08-28 | 1976-05-19 | Bayer Ag | Process for consolidating radioactive waste solutions |
| CN102557577A (en) * | 2011-11-01 | 2012-07-11 | 厦门纳美特新材料科技有限公司 | Preparation and method of silicon dioxide aerogel composite material |
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| US3126352A (en) * | 1958-12-31 | 1964-03-24 | Certificate of correction | |
| FR2717709B1 (en) * | 1994-03-22 | 1996-04-26 | Commissariat Energie Atomique | Gel capable of retaining radioactive contamination and its use to protect or decontaminate a surface. |
| FR2827530B1 (en) * | 2001-07-17 | 2004-05-21 | Commissariat Energie Atomique | PROCESS FOR TREATING A SURFACE WITH A TREATMENT GEL, AND TREATMENT GEL |
| FR2891470B1 (en) * | 2005-10-05 | 2007-11-23 | Commissariat Energie Atomique | ASPIRABLE GEL FOR DECONTAMINATION OF SURFACES AND USE |
| JP2013234918A (en) * | 2012-05-09 | 2013-11-21 | Osaka Yushi Kogyo Kk | Composition for adsorbing radioactive material, coating peeling type radioactive decontamination material, decontamination technique, and decontamination and shielding technique |
| FR3054839B1 (en) * | 2016-08-05 | 2020-06-26 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | SUCTION GEL AND METHOD FOR ELIMINATING RADIOACTIVE CONTAMINATION CONTAINED IN AN ORGANIC LAYER ON THE SURFACE OF A SOLID SUBSTRATE. |
| WO2018044728A1 (en) * | 2016-09-01 | 2018-03-08 | Commscope Technologies Llc | End face cleaning gel for hardened multi-fiber optical connectors; and methods |
| CN106565224B (en) * | 2016-10-18 | 2019-04-26 | 深圳市华天启科技有限公司 | A kind of method of mullite fiber enhancing aerosil |
| CN109799528B (en) * | 2019-01-17 | 2022-08-19 | 中国辐射防护研究院 | Oxidized gel for sampling radioactive contaminated metal shallow layer and preparation method thereof |
| CN111909559B (en) * | 2020-08-14 | 2022-05-10 | 西南科技大学 | Radioactive surface strippable detergent and preparation method thereof |
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| GB1435855A (en) * | 1973-08-28 | 1976-05-19 | Bayer Ag | Process for consolidating radioactive waste solutions |
| CN102557577A (en) * | 2011-11-01 | 2012-07-11 | 厦门纳美特新材料科技有限公司 | Preparation and method of silicon dioxide aerogel composite material |
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