TWI719686B - Method of evaluating dispersion of pollutants in whole rock matrix through scanning electron microscopy and energy scatter analysis - Google Patents

Abstract

A method is provided for evaluating the dispersion of pollutants in a whole rock matrix. The method is done through scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). On obtaining a rock sample, detection and examination of contaminant diffusion are processed. A clean-cut method is used to ensure reduction in redistribution or contamination on a section of the sample. SEM is used to analyze an image of a cross-sectional area of the contaminated sample. Inductively coupled plasma atomic emission spectrometry (ICP-AES) or inductively coupled plasma-mass spectrometry (ICP-MS) is supplemented to identify spectrum for confirming and analyzing elements of the contaminated sample. At last, SEM is combined with EDS to analyze specific contaminants in the cross-sectional area of the contaminated sample. When EDS is combined with image tools, a region having a diameter smaller than nano-meter scale is provided to process elemental analysis for image scanning and analysis of the sample. Thus, the characterized X-rays of the elements of the contaminated sample obtained by striking the contaminated sample with an electron beam is used to determine the elemental composition at a single point for analysis of the diffusion degree of the pollutant elements in the section of the contaminated sample. In such a way, a lateral concentration profile of pollutant elements in the imaged region is plotted.

Description

Analytical method to evaluate the diffusion of pollutants in intact rock matrix by scanning electron microscope and energy dispersion analysis

The present invention relates to a scanning electron microscope and energy dispersion analysis and evaluation Analysis methods for the diffusion of pollutants in intact rock substrates, especially those that can be applied to the study of the diffusion of radioactive contaminants in rocks for the final disposal of used nuclear fuel, environmental protection, and the identification and analysis of industrial pollution diffusion.

The traditional analysis method for analyzing the diffusion of pollutants in the intact parent rock matrix is penetration diffusion Method, internal diffusion, or use the well site to conduct on-site tracer tests. Among them, the penetration diffusion method in the rock diffusion analysis method takes too long to complete, and it takes several years to complete; the internal diffusion method currently known in the literature requires the use of X-ray photoelectron spectrometer (X-ray photoelectron spectrometer, XPS), pull plug Rutherford backscattering spectrometer (RBS), secondary ion mass spectrometer (SIMS) and other expensive precision instruments can only be carried out; however, the tracer test and test used for on-site excavation will cause environmental pollution. Of doubts. Traditional grinding and cutting samples will also redistribute or contaminate part of the material components in the sample slices, causing analytical uncertainty.

In view of the current domestic and foreign analysis methods for the diffusion of pollutants in the intact parent rock, traditional research Grinding and cutting the sample will redistribute or contaminate part of the material components in the sample slice, causing analysis inconsistencies. Certainty; traditional radioactive pollutants are diffused in the environment, and tracer testing cannot be performed on-site due to environmental protection and safety factors; the traditional penetrating diffusion method is limited by the long experimental time and the result cannot be known in a short time; traditional internal diffusion The method requires expensive precision instruments to perform analysis. Although there have been patents that cover scanning electron microscopes that can use multi-pixel solid-state electronic detectors for image magnification and inspection of the sample surface, it does not mention the application of combining energy dispersive spectroscopy to analyze the element distribution of samples. Therefore, general users cannot meet the needs of users in actual use.

The main purpose of the present invention is to overcome the above-mentioned problems encountered by the prior art and to improve Provide a scanning electron microscope combined with an energy dispersion analysis instrument to analyze the cut rock or geological sample section. First, perform scanning electron microscope analysis on the surface of the sample surface image analysis, supplemented by inductively coupled plasma atomic emission spectroscopy or inductively coupled electrical The plasma mass spectrometer identified the spectrum to confirm and analyze the element composition of the contaminated sample, and finally scanned with the energy dispersive analysis instrument to map the horizontal distribution of the contaminant elements in the imaging area, ensuring that radioactive contaminants can be used in the laboratory to study the diffusion behavior of geological materials. Scanning electron microscopy and energy dispersion analysis are an analytical method to evaluate the diffusion of pollutants in the intact rock matrix.

The secondary objective of the present invention is to provide a method that can be applied to the final Disposal of radioactive contaminants in rock diffusion research, environmental protection, and industrial pollution diffusion identification analysis. Scanning electron microscope and energy dispersion analysis are used to evaluate the analysis method of pollutant diffusion in intact rock substrates.

In order to achieve the above purpose, the present invention is a scanning electron microscope and energy dispersing An analytical method for analyzing and evaluating the diffusion of contaminants in the intact rock matrix, which at least includes the following steps: Sample An analysis method for analyzing and evaluating the diffusion of contaminants in a complete rock matrix, which at least includes the following steps: Sample pretreatment step: Obtain a rock sample, cut, grind and polish the rock sample before processing, and cut the rock sample into rock Among the thin slice samples, the rock thin slice samples are processed to a thickness of 0.03～0.5 millimeters (mm), and then they are ground and polished to form a flat rock thin slice sample; the pollution diffusion step: the rock thin slice sample with a flat surface is first subjected to water saturation treatment. Then soak the contaminants for contamination diffusion to form a rock flake contaminated sample; non-polluting cutting steps: stick a glass slice on the back of the rock flake contaminated sample, and use a diamond knife scribing or laser scribing method to cut the end of the glass slice during the slicing process. Make the sliced rock flakes contaminated sample can be completely adhered to the glass sheet and not easily broken, so as to reduce the redistribution or pollution on the section; and the scanning analysis section step: scan the section of the rock flakes contaminated sample after the slicing process. Microscope (SEM) analyzes the image of the cross-sectional area of the contaminated sample, supplemented by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS) to identify the spectrum to confirm and analyze the element composition of the contaminated sample, and finally Scanning electron microscope combined with energy dispersion analysis instrument (SEM-EDS) analyzes specific pollutant elements in the cross-sectional area of the contaminated sample. When the energy dispersion analysis instrument is combined with these imaging tools, it can provide an area as small as nm in diameter for element analysis. Analyze, perform image scanning and analysis of the sample. By using the electron beam to collide with the contaminated sample, the characteristic X-ray of the contaminated sample element will be generated, which can be used to determine the elemental composition of a single point and analyze the contaminant element in the rock flake contaminated sample The degree of diffusion in the imaging area draws the horizontal concentration distribution map of the pollutant elements in the imaging area.

In the above-mentioned embodiment of the present invention, the rock sample is hard granite, basalt The igneous rock of martial or andesite.

In the above-mentioned embodiment of the present invention, the water saturation treatment time for the rock flake sample is For 7 to 30 days.

In the above embodiment of the present invention, the rock flake sample is immersed in a concentration greater than For 0.001M pollutants, the soaking time is 7-30 days.

In the above-mentioned embodiment of the present invention, the diamond knife scribing system adds a notch to the cut to make Local stress is concentrated and breakage is achieved.

In the above-mentioned embodiment of the present invention, the laser scribing is made by using a high-energy density laser in the brittle The surface of the glass sheet of the material is scanned, the material is heated to evaporate a small groove, and then a certain pressure is applied to crack the glass sheet along the small groove.

Please refer to "Figure 1 to Figure 3", which are the flow of the analysis method of the present invention. The schematic diagram of the process, the schematic diagram of the pollution-free cutting process of the present invention, and the schematic diagram of image analysis of the analysis method of the present invention. As shown in the figure: The present invention is an analysis method for evaluating the diffusion of pollutants in the intact rock matrix by scanning electron microscope and energy dispersion analysis. It is mainly for the pollutant diffusion test and detection after the rock sample is obtained. It includes at least the following step:

Sample pre-processing step s11: Obtain a rock sample 1, which can be quality For the hard granite, basalt or andesite igneous rock, the rock sample 1 is cut, ground and polished, and the rock sample is cut into rock flake sample 1a, and the thickness of the rock flake sample 1a is processed to 0.03～0.5 Millimeter (mm), and then ground and polished into a flat rock flake sample 1a.

Pollution diffusion step s12: After cutting and grinding in the laboratory, the rock with a smooth surface The rock flake sample 1a is subjected to water saturation treatment for 7-30 days. After the rock flake sample 1a is saturated with water, it is immersed in a pollutant with a concentration greater than 0.001M for 7-30 days for pollution diffusion to form a rock flake pollution sample 1b.

Non-polluting cutting step s13: paste glass on the back of the rock flake contaminated sample 1b Sheet 2, the slicing process uses a diamond knife scribing or laser scribing method to cut the 2 ends of the glass sheet. The diamond knife scribing utilizes the brittleness, low tensile stress and residual stress characteristics of the sample, and adds a moment to the cut. This laser scribing system uses a high-energy density laser to scan the surface of the glass sheet 2 of the brittle material, so that the material is heated to evaporate a small groove, and then a certain pressure is applied to make the glass Piece 2 splits along the small groove. The cut rock slice contaminated sample 1b can be completely adhered to the glass sheet 2 and not easily broken. This method can ensure that the sample can achieve the reduction of redistribution or pollution on the cut surface.

Scanning and analyzing section step s14: contaminate the sample 1b of the rock slice after the slice processing Scanning electron microscopy (SEM) analysis of the profile of the contaminated sample profile area image, supplemented by inductively coupled plasma atomic emission spectrometry (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS) to identify the spectrum to confirm the analysis of the contaminated sample The element composition is finally analyzed by scanning electron microscope combined with energy dispersion analysis instrument (SEM-EDS) to analyze specific pollutant elements in the section area of the contaminated sample. When the energy dispersion analysis instrument is combined with these imaging tools, the diameter can be as small as Elemental analysis is performed in the nm region, and image scanning and analysis of the sample are performed. As shown in Figure 3, the black dots in the figure are the distribution of pollutants. The characteristic X-rays excited by the electron beam are used to analyze the element distribution of the rock flake contamination sample 1b to distinguish the sample matrix and the rock flake contamination. The element distribution analysis of sample 1b analyzes the degree of diffusion of pollutant elements in the rock flake contamination sample, and plots the horizontal distribution of pollutant elements in the imaging area. It can also be applied to the experimental study of nuclear species migration evaluation for the final disposal of used nuclear fuel. . If so, the above-mentioned disclosure process constitutes a brand new one.

The following examples are only examples for understanding the details and connotation of the present invention, but not for limitation The scope of patent application of the present invention.

In a specific embodiment, the obtained rock sample 1 is granite as an example. When in use, first perform granite pre-processing, cutting, grinding, and polishing steps, and process the rock flake sample 1a to a thickness of 0.03mm. After cutting and grinding in the laboratory, the rock flake sample 1a with a flat surface is subjected to water saturation treatment for 7 days. After the granite rock flake sample 1a is saturated with water, it is immersed in a gold-containing colloid solution and formed by immersion treatment for 7 days. After the rock flakes contaminate the sample for 1b, follow-up sectioning is performed. In the sample slicing step, the glass sheet 2 must be attached to the back of the rock flake contaminated sample 1b. The slicing process uses a diamond knife scribing or laser scribing method to cut the 2 ends of the glass sheet, and the diamond knife scribing is based on the sample. The characteristics of brittleness, low tensile stress and residual stress, add a notch to the cutting place, causing local stress concentration, and then it can be broken; this laser scribing system uses a high-energy density laser to scan the surface of brittle materials. The material is heated to evaporate into a small groove, and then a certain pressure is applied, and the brittle material will crack along the small groove. The cut rock flake contaminated sample 1b can be completely adhered to the glass flake 2 and will not break easily. This method can ensure that the sample reduces redistribution or contamination on the cut surface. After the sample is sliced and processed, follow-up scanning electron microscope analysis of the contaminated sample section of the rock slice to be analyzed is performed to analyze the composition of the contaminated sample section area, supplemented by inductively coupled plasma atomic emission spectroscopy or inductively coupled plasma mass spectrometer to identify the spectrum confirmation Analyze the element composition of the contaminated sample, and finally analyze the specific pollutant elements in the cross-sectional area of the contaminated sample with a scanning electron microscope combined with an energy dispersion analysis instrument. When the energy dispersion analysis instrument is combined with these imaging tools, it can provide diameters as small as nm Elemental analysis of the area. The impact of the electron beam on the contaminated sample will produce the characteristic X-ray of the contaminated sample element. The energy dispersion analysis instrument analysis can be used to determine the elemental composition of a single point. It can analyze the diffusion of colloidal gold in the granite and map out the gold element in the imaging area. Lateral concentration distribution diagram. The diffusion behavior of the solute is expressed by Fick's law. The diffusion behavior of the solute in the porous medium uses Fick's second law (one-dimensional diffusion equation in the medium). The diffusion can be obtained by the equation It can be calculated that the diffusion coefficient of 20nm gold colloid on granite ranges from 10 ^-16 m ² /s to 10 ^-17 m ² /s.

Therefore, the present invention mainly uses scanning electron microscope combined with energy dispersion analyzer Analyze the cut rock or geological sample section, first perform scanning electron microscope analysis on the surface of the sample surface image analysis, supplemented by inductively coupled plasma atomic emission spectroscopy or inductively coupled plasma mass spectrometer to identify spectra confirmation analysis of contaminated sample elements The composition is finally scanned with an energy dispersion analysis instrument to map the horizontal distribution of pollutant elements in the imaging area, ensuring that radioactive pollutants can be studied in the laboratory for the diffusion behavior of geological materials.

In summary, the present invention is a scanning electron microscope and energy dispersion analysis evaluation The analysis method for estimating the diffusion of pollutants in the complete rock matrix can effectively improve the various shortcomings of the conventional use. It can be applied to the study of the diffusion of radioactive contaminants in the rock, environmental protection and industrial pollution diffusion identification and analysis of the used nuclear fuel. The creation of an invention can be more advanced, more practical, and more in line with the needs of users, and it has indeed met the requirements of an invention patent application, and a patent application is filed in accordance with the law.

However, the above are only the preferred embodiments of the present invention, and should not be limited by this The scope of implementation of the present invention; therefore, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the description of the invention should still fall within the scope of the patent of the present invention.

1: Rock samples 1a: Rock slice sample 1b: Rock flake contamination sample 2: Glass sheet s11～s14: steps

Figure 1 is a schematic flow diagram of the analysis method of the present invention. Figure 2 is a schematic diagram of the pollution-free cutting process of the present invention. Figure 3 is a schematic diagram of image analysis of the analysis method of the present invention.

1: Rock sample

1a: Rock flake sample

1b: Rock flake contamination sample

2: glass sheet

s11~s14: steps

Claims (4)

An analysis method for evaluating the diffusion of pollutants in an intact rock matrix by scanning electron microscope and energy dispersive analysis, which at least includes the following steps: Sample pretreatment step: Obtain a rock sample, and process the rock sample before cutting, grinding and polishing Processing, cutting the rock sample into rock flake samples, processing the rock flake sample to a thickness of 0.03~0.5 millimeters (mm), and then grinding and polishing to form a rock flake sample with a flat surface; pollution diffusion step: flatten the surface The rock flake samples are first saturated with water, and then the contaminants are soaked for contamination and diffusion to form rock flake contaminated samples; non-polluting cutting steps: a glass flake is pasted on the back of the rock flake contaminated sample, and the slicing process is cut with a diamond knife or thunder The end of the glass piece is cut by shooting scribing. The diamond knife scribing system adds a notch to the cutting position to concentrate local stress and achieve breakage. The laser scribing system uses high-energy density lasers on the surface of the glass sheet of brittle materials. Scanning, heat the material to evaporate into a small groove, and then apply a certain pressure to crack the glass sheet along the small groove, so that the cut rock flake contaminated sample can be completely adhered to the glass sheet and is not easy to break, reducing the cut surface Redistribution or contamination on the surface; and scanning analysis section steps: Scanning electron microscopy (SEM) analysis of the contaminated sample section area image of the contaminated sample section of the rock slice after the slicing process, supplemented by inductively coupled plasma atomic emission spectroscopy ( ICP-AES) or Inductively Coupled Plasma Mass Spectrometer (ICP-MS) identified the spectra to confirm and analyze the elemental composition of the contaminated sample, and finally analyzed the specific pollutants in the section of the contaminated sample with scanning electron microscope combined with energy dispersive analysis instrument (SEM-EDS) When the energy dispersion analysis instrument is combined with these imaging tools, it can provide an area as small as nm in diameter for element analysis. Analyze, perform image scanning and analysis of the sample. By using the electron beam to collide with the contaminated sample, the characteristic X-ray of the contaminated sample element will be generated, which can be used to determine the element composition of a single point and analyze the contaminant element in the rock flake contaminated sample The degree of diffusion in the imaging area draws the horizontal concentration distribution map of the pollutant elements in the imaging area. According to the first item of the scope of patent application, scanning electron microscope and energy dispersive analysis are used to evaluate the diffusion of pollutants in a complete rock matrix, wherein the rock sample is igneous rock of hard granite, basalt or andesite. According to the first item of the scope of patent application, the scanning electron microscope and energy dispersive analysis method is used to evaluate the diffusion of pollutants in the intact rock matrix, wherein the water saturation treatment time for the rock flake samples is 7 to 30 days. According to the first item of the scope of patent application, scanning electron microscope and energy dispersive analysis are used to evaluate the diffusion of pollutants in the intact rock matrix, wherein the rock flake sample is immersed in pollutants with a concentration greater than 0.001M. The time is 7 to 30 days.

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