Standardized high-purity quartz sand sample pretreatment and element detection method
By combining high-precision weighing and a standardized process of acid treatment with a perforated graphite digester, the problems of incomplete digestion and poor consistency of quartz sand samples were solved, achieving efficient and accurate detection of quartz sand impurities and reducing instrument maintenance costs.
Patent Information
- Application Number
- CN202511039662.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-28
- Publication Date
- 2025-10-17
AI Technical Summary
In traditional elemental analysis of quartz sand, the graphite heating plate has poor temperature control accuracy, incomplete sample digestion, and the sample preparation process cannot be standardized, resulting in poor test consistency and result deviation.
Quartz sand samples were weighed using a high-precision electronic balance and digested using a perforated graphite digester. The digestion was combined with treatment with high-purity hydrofluoric acid and nitric acid. A standardized process was used to ensure thorough digestion and reliable results. Elemental analysis was performed using ICP-OES.
It improves the accuracy and efficiency of quartz sand impurity detection, reduces instrument maintenance costs, has a wide range of applications, and provides good reproducibility of test results, making it suitable for large-scale analysis.
Smart Images
Figure CN120800940A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of quartz sand sample detection methods, and in particular to a standardized high-purity quartz sand sample pretreatment and element detection method. Background Art
[0002] High purity quartz sand ( Quartz sand (purity ≥99.99%) is a key material in semiconductor chip manufacturing, photovoltaic monocrystalline silicon production and other fields. Its impurity elements, such as aluminum, iron, potassium, sodium, titanium, etc., their content directly affects the yield and performance of the product. ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer), with its advantages such as multi-element detection and high sensitivity, has become the core means of impurity analysis in the quartz sand industry.
[0003] The traditional quartz sand element detection sample preparation method has the following technical limitations: ① The commonly used digestion instrument for traditional sample preparation is a graphite heating plate, but its temperature control accuracy is poor and the temperature distribution is uneven, resulting in poor sample test consistency; ② The traditional method has a low digestion temperature, which results in incomplete sample digestion, affecting the release of impurities. Meanwhile, residual particles clog the ICP-OES nebulizer, increasing instrument maintenance costs. ③ The sample preparation process is not standardized, which may introduce variables, making the experimental results difficult to reproduce or the test results biased.
[0004] Therefore, in order to address the problems that the commonly used digestion instrument for traditional sample preparation is a graphite heating plate, but its temperature control accuracy is poor, the sample digestion is incomplete, and the sample preparation process cannot be standardized for detection, a standardized high-purity quartz sand sample pretreatment and element detection method can be designed. Summary of the Invention
[0005] In order to overcome the problems of traditional sample preparation, the commonly used digestion instrument is a graphite heating plate, but its temperature control accuracy is poor, the sample digestion is incomplete, and the sample preparation process cannot be standardized for detection.
[0006] The technical solution of the present invention is: a standardized high-purity quartz sand sample pretreatment and element detection method, the steps of which are as follows: S1: Sample preparation Place the quartz sand sample in a suitable drying device for drying, and then use a high-precision electronic balance to accurately weigh 1g of the dried quartz sand sample; S2: Sample digestion S21: Acidification operation Transfer the weighed quartz sand sample into a polytetrafluoroethylene digestion tube and accurately add 10 ml of high-purity hydrofluoric acid using a pipette; S22: Digestion process Put the polytetrafluoroethylene digestion tube containing the sample and hydrofluoric acid into a hole type graphite digestion instrument to digest the sample, make the strong acid vapor reflux, fully contact with the quartz sand, accelerate the conversion of the silicon matrix, release the metal element impurities therein, and realize complete digestion; S3: acid chasing treatment After the digestion is completed, the cover of the digestion tube is opened, and the digestion tube is continuously placed in the graphite digestion instrument for constant temperature heating for 60 minutes, so that the excess hydrofluoric acid is fully evaporated until the volume of the solution is less than 0.5 ml. S4: dissolution and constant volume After the acid chasing is completed, after the digestion tube is slightly cooled, 15 ml of nitric acid solution is added by using a pipette, and the remaining solids are fully dissolved by using the residual heat of the digestion tube for continuous heating. S5: constant volume operation The dissolved solution is transferred to a volumetric flask, a small amount of nitric acid solution is used to rinse the digestion tube for multiple times, the rinsing liquid is transferred to the volumetric flask, and then the volumetric flask is added with the nitric acid solution to 1-2 cm below the scale line, waits for 1-2 minutes to fully mix the solution, and then the nitric acid solution is added drop by drop to the scale line by using a dropper to obtain a sample solution to be measured. S6: standard curve drawing A series of standard solutions with different concentrations are prepared and are sequentially introduced into an inductively coupled plasma optical emission spectrometer (ICP-OES) for determination. S7: sample detection and data analysis The prepared sample solution to be measured is introduced into the ICP-OES instrument, and determination and analysis are performed according to the same instrument parameters as those for drawing the standard curve.
[0007] As preferred, in the S1 step, the drying equipment is specifically a constant temperature drying box, the drying temperature is between 105-110°C, and the time is between 4-6 hours. The drying can remove the water in the sample, ensure the stable state of the sample, and after the drying is completed, the sample is taken out and cooled to room temperature in a desiccator.
[0008] As preferred, in the S21 step, the high-purity hydrofluoric acid is UPS grade with a concentration of 49%. After the hydrofluoric acid is added, the cover of the digestion tube is immediately covered to prevent the volatilization of the hydrofluoric acid. This step needs to be performed in an anti-corrosion fume hood, and the operator needs to wear special protective equipment for hydrofluoric acid.
[0009] As preferred, in the S22 step, the temperature difference between the holes of the hole type graphite digestion instrument is less than 2°C to ensure the uniformity of the digestion temperature. The hole type graphite digestion instrument is set with appropriate digestion temperature and time parameters according to the characteristics of the quartz sand sample and experimental requirements. The initial temperature is set to 80°C and is maintained for 30 minutes, then is increased to 120°C and is maintained for 60 minutes, and then is increased to 180°C and is maintained for 120 minutes.
[0010] As preferred, in the step S3, the temperature of the graphite digester is set to 150-180 DEG C, and the volume change of the solution is closely observed during the acid-removing process to prevent the solution from being evaporated to dryness and causing the loss of elements.
[0011] As preferred, in the step S4, the concentration of the nitric acid solution is 2-100, i.e. 2% nitric acid solution, and the inner wall of the digestion tube is rinsed with the nitric acid solution for 3 times to ensure that the sample is completely dissolved and transferred into the solution.
[0012] As preferred, in the step S5, a 50ml volumetric flask is used, and the nitric acid solution is added dropwise to the graduation line, and then the solution is tangent to the graduation line at the lowest point of the concave liquid surface, and then the volumetric flask is capped and inverted for 15-20 times to mix the solution evenly.
[0013] As preferred, in the step S6, the concentration range of the standard solution can cover the possible content range of the elements in the sample to be measured, and the mixed standard solution with the concentrations of 0.1ug / ml, 0.5ug / ml, 1.0ug / ml, 5.0ug / ml and 10.0ug / ml is prepared, and during the preparation process, the high-precision pipetting equipment is used to accurately measure the standard stock solution and the diluent to ensure the accuracy of the concentration of the standard solution.
[0014] As preferred, in the step S6, when the prepared mixed standard series is introduced into the inductively coupled plasma emission spectrometer, the determination is performed according to the pump speed of 12rpm, the power of 1.2KW, the atomizer flow of 0.7L / min, the plasma gas flow of 12.0L / min and the auxiliary gas flow of 1L / min, the characteristic spectral line intensity of each element in each standard solution is recorded, the standard curve is drawn by using the data processing software or Origin with the concentration of the standard solution as the abscissa and the characteristic spectral line intensity as the ordinate, and the linear relationship equation between the element concentration and the characteristic spectral line intensity is obtained.
[0015] As preferred, in the step S7, during the determination, the sample solution is atomized by the instrument to enter the plasma in the form of aerosol, and is fully evaporated, atomized, ionized and excited in the high temperature and inert atmosphere to emit the characteristic spectral line of the contained elements, and then the characteristic spectral line intensity of each element in the sample solution is recorded, the characteristic spectral line intensity of each element in the sample solution is substituted into the linear relationship equation of the standard curve to calculate the concentration of the corresponding element in the sample, the content of each element impurity in the quartz sand is further calculated by combining the weighing mass and the constant volume of the sample, the qualitative and quantitative analysis of the elements in the quartz sand sample is completed, and the repeatability and accuracy of the experimental data are verified to ensure the reliability of the detection results.
[0016] The beneficial effects of the present application are as follows: The application significantly improves the precision and efficiency of quartz sand impurity detection by innovative sample preparation method and device, and has the comprehensive advantages of low cost and easy operation. Compared with the traditional quartz sand element detection method, the core progress is as follows: first, by increasing the sample preparation temperature, the detection of samples of different processes of different mineral sources can be applied, the application range is wide, and the detection accuracy is high; second, the whole process does not need to use too many reagents and processing steps, which is very suitable for large-scale analysis and detection, and improves the detection efficiency; third, after sample preparation, the digestion is complete, there is no obvious sample particle, the residual hydrofluoric acid is less, the instrument corrosion and damage are reduced, and the instrument maintenance cost is reduced; fourth, the process is standardized, the number of introduced variables is small, and the experimental results have good reproducibility. The scheme provides an efficient, economical and reliable integrated solution for quartz sand impurity detection, and has important application value for high-purity quartz sand product quality control. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 A flowchart of the standardized high-purity quartz sand sample pretreatment and element detection method of the application is shown. DETAILED DESCRIPTION
[0018] The application will be further described below in combination with the drawings and examples.
[0019] The application provides an example of a standardized high-purity quartz sand sample pretreatment and element detection method, which comprises the following steps: S1: sample preparation The quartz sand sample is placed in a suitable drying device for drying, which can remove the water in the sample and ensure the stability of the sample state. After drying, the sample is taken out and cooled to room temperature in a desiccator. Then, 1g of the dried quartz sand sample is accurately weighed using a high-precision electronic balance. The drying device specifically uses a constant temperature drying box, and the drying temperature is between 105-110 DEG C, and the time is between 4-6 hours. S2: sample digestion S21: acid addition operation The weighed quartz sand sample is transferred to a polytetrafluoroethylene digestion tube, and 10ml of high-purity hydrofluoric acid is accurately added using a pipette. After adding the hydrofluoric acid, immediately cover the digestion tube cap to prevent the volatilization of the hydrofluoric acid. This step needs to be carried out in an anti-corrosion fume hood, and the operator must wear hydrofluoric acid special protective equipment. The high-purity hydrofluoric acid is UPS grade, and the concentration is 49%. S22: digestion process Put the polytetrafluoroethylene digestion tube containing the sample and hydrofluoric acid into the hole type graphite digestion instrument to digest the sample, make the strong acid vapor reflux, and fully contact with the quartz sand to accelerate the conversion of the silicon matrix and release the metal element impurities therein, realize complete digestion, the temperature difference between the holes of the hole type graphite digestion instrument is less than 2°C, and the uniformity of the digestion temperature is ensured; the hole type graphite digestion instrument is set with appropriate digestion temperature and time parameters according to the sample characteristics and experimental requirements of the quartz sand, the initial temperature is set to 80°C and maintained for 30 minutes, then the temperature is raised to 120°C and maintained for 60 minutes, and then the temperature is raised to 180°C and maintained for 120 minutes; S3: acid chasing treatment After the digestion is completed, open the cover of the digestion tube, continue to place the digestion tube in the graphite digestion instrument, and maintain constant temperature heating for 60 minutes to fully evaporate the excess hydrofluoric acid until the solution volume is less than 0.5ml, closely observe the solution volume change during the acid chasing process to prevent the solution from being evaporated dry and causing element loss, and the temperature of the graphite digestion instrument is set to 150-180°C; S4: dissolution and constant volume After the acid chasing is completed, after the digestion tube is slightly cooled, 15ml of nitric acid solution is added using a pipette, the remaining heat of the digestion tube is used for continuous heating to fully dissolve the remaining solid, and the inner wall of the digestion tube is rinsed with the nitric acid solution for three times to ensure that the sample is completely dissolved and transferred to the solution, and the concentration of the nitric acid solution is 2→100, i.e. 2% nitric acid solution; S5: constant volume operation Transfer the dissolved solution to a volumetric flask, use a 50ml volumetric flask, rinse the digestion tube with a small amount of nitric acid solution for multiple times, transfer the rinsing liquid to the volumetric flask, then add the nitric acid solution to the volumetric flask to 1-2cm below the scale line, wait for 1-2 minutes to fully mix the solution, add the nitric acid solution drop by drop to the scale line using a dropper, the lowest point of the solution concave liquid surface is tangent to the scale line, then cover the volumetric flask plug, invert the volumetric flask 15-20 times to fully mix the solution, and obtain the sample solution to be measured; S6: standard curve drawing Prepare a series of standard solutions with different concentrations, sequentially introduce into an inductively coupled plasma optical emission spectrometer (ICP-OES) for determination, the concentration range of the standard solution can cover the possible content range of the elements in the sample to be measured, and specifically, a mixed standard solution with concentrations of 0.1μg / ml, 0.5μg / ml, 1.0μg / ml, 5.0μg / ml and 10.0μg / ml is prepared; during the preparation process, high-precision pipetting equipment is used to accurately measure the standard stock solution and the diluent to ensure the accuracy of the concentration of the standard solution; The prepared mixed standard series is introduced into the inductively coupled plasma emission spectrometer in sequence, and the determination is performed at a pump speed of 12 rpm, a power of 1.2 KW, an atomizer flow of 0.7 L / min, a plasma gas flow of 12.0 L / min, and an auxiliary gas flow of 1 L / min; the characteristic spectral line intensity of each element in each standard solution is recorded, the concentration of the standard solution is taken as the abscissa, and the characteristic spectral line intensity is taken as the ordinate; the standard curve is drawn by using the data processing software or Origin, and the linear relationship equation between the element concentration and the characteristic spectral line intensity is obtained; S7: sample detection and data analysis The prepared sample solution to be detected is introduced into the ICP-OES instrument, and the determination and analysis are performed according to the same instrument parameters as those for drawing the standard curve; During the determination, the instrument automatically atomizes the sample solution, which enters the plasma in the form of aerosol, is fully evaporated, atomized, ionized and excited in the high temperature and inert atmosphere, emits the characteristic spectral lines of the contained elements, and then records the characteristic spectral line intensity of each element in the sample solution; According to the linear relationship equation of the standard curve, the characteristic spectral line intensity of each element in the sample solution is substituted into the equation to calculate the concentration of the corresponding element in the sample, and the content of each element impurity in the quartz sand is further calculated by combining the weighing mass and the constant volume of the sample, thereby completing the qualitative and quantitative analysis of the elements in the quartz sand sample. At the same time, the repeatability and accuracy of the experimental data are verified to ensure the reliability of the detection results.
[0020] The detection wavelengths and observation modes of each element are as follows:
[0021] Experimental example Select high-purity quartz sand samples of different mineral sources (purity ≥ 99.99%) Prepare sufficient samples of each mineral source for experimental group and control group experiments.
[0022] Divide the quartz sand samples of each mineral source into two groups, one group uses the above embodiment as experimental example 1, and the other group uses the traditional method as experimental example 2. The traditional method uses a traditional graphite heating plate, sets a fixed digestion temperature of 100℃ and a relatively short digestion time, such as 60 minutes, and performs digestion. Other operation steps are consistent with the experimental group as much as possible, but do not follow the standardized process, and the sample preparation process has certain randomness.
[0023] Repeat the operation of the experimental group and the control group of each mineral source for 3 times respectively, clean and maintain the ICP-OES instrument after each experiment, and record the problems found during the instrument maintenance and the maintenance cost; Data recording content: 1) The digestion degree of the sample in each experiment is judged by observing whether the solution is clear and whether there are residual particles, and is divided into three levels of complete digestion, partial digestion and incomplete digestion; 2) The characteristic spectral line intensity of each element such as aluminum, iron, potassium, sodium and titanium, and the calculated element content; 3) The relative deviation of the test result, the relative deviation=(single measurement value-average value) / average value*100%, which is used to measure the test consistency; 4) The reproducibility of the experimental results, whether the results of multiple experiments are similar, divided into three levels of easy reproducibility, relatively difficult reproducibility and difficult reproducibility; 5) The instrument maintenance cost, that is, the cost required for maintenance after each experiment is recorded; The data records are as follows:
[0024] Through the comparison of the experimental data of different mineral source quartz sand samples, it can be known that the high-purity quartz sand sample pretreatment and element detection method is significantly better than the traditional method in the aspects of digestion effect, test consistency, experimental result reproducibility and reduction of instrument maintenance cost, the method can more stably, accurately and efficiently detect the impurity element content in the quartz sand, effectively solves the technical limitations existing in the traditional method, and provides more reliable technical support for the quality detection of quartz sand in the fields of semiconductor chip manufacturing, photovoltaic monocrystalline silicon production and the like.
Claims
1. A standardized high-purity quartz sand sample pretreatment and element detection method, characterized in that: The steps are as follows: S1: Sample preparation Place the quartz sand sample in a suitable drying device for drying, and then use a high-precision electronic balance to accurately weigh 1g of the dried quartz sand sample; S2: Sample digestion S21: Acidification operation Transfer the weighed quartz sand sample into a polytetrafluoroethylene digestion tube and accurately add 10 ml of high-purity hydrofluoric acid using a pipette; S22: Digestion process Place the polytetrafluoroethylene digestion tube containing the sample and hydrofluoric acid into a perforated graphite digester to digest the sample, allowing the strong acid vapor to reflux and fully contact with the quartz sand, accelerating the transformation of the silicon matrix and releasing the metal element impurities therein to achieve complete digestion; S3: Acid removal treatment After digestion is completed, open the lid of the digestion tube and continue to place the digestion tube in the graphite digester. Keep heating at a constant temperature for 60 minutes to fully evaporate the excess hydrofluoric acid until the solution volume is less than 0.5 ml. S4: Dissolve and adjust to volume After the acid is removed, wait for the digestion tube to cool slightly, add 15 ml of nitric acid solution using a pipette, and continue heating with the residual temperature of the digestion tube to fully dissolve the remaining solids. S5: Constant volume operation Transfer the dissolved solution to a volumetric flask, rinse the digestion tube several times with a small amount of nitric acid solution, transfer the rinse solution to the volumetric flask, then add nitric acid solution to the volumetric flask to 1-2 cm below the scale line, wait 1-2 minutes to allow the solution to be fully mixed, and use a dropper to add nitric acid solution dropwise to the scale line to obtain the sample solution to be tested; S6: Standard curve drawing Prepare a series of standard solutions with different concentrations and introduce them into inductively coupled plasma optical emission spectrometer (ICP-OES) for measurement; S7: Sample testing and data analysis The prepared sample solution to be tested is introduced into the ICP-OES instrument and measured and analyzed according to the same instrument parameters as those used to draw the standard curve.
2. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S1, the drying equipment specifically uses a constant temperature drying oven with a drying temperature between 105-110°C and a drying time between 4-6 hours. Drying can remove moisture from the sample and ensure that the sample state is stable. After drying is completed, the sample is taken out and placed in a desiccator to cool to room temperature.
3. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S21, the high-purity hydrofluoric acid is UPS grade with a concentration of 49%. After adding hydrofluoric acid, the digestion tube lid should be immediately covered to prevent the volatilization of hydrofluoric acid. This step must be performed in a corrosion-resistant fume hood, and the operator must wear special hydrofluoric acid protective equipment.
4. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S22, the temperature difference between the holes of the hole-type graphite digester is less than 2°C to ensure the uniformity of the digestion temperature; the hole-type graphite digester sets appropriate digestion temperature and time parameters according to the characteristics of the quartz sand sample and the experimental requirements. The initial temperature is set to 80°C, maintained for 30 minutes, then raised to 120°C, maintained for 60 minutes, and then raised to 180°C, maintained for 120 minutes.
5. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S3, the temperature of the graphite digester is set to 150-180°C. During the acid removal process, the volume change of the solution is closely observed to prevent the solution from evaporating and causing element loss.
6. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S4, the concentration of the nitric acid solution is 2→100, i.e., a 2% nitric acid solution; at the same time, the inner wall of the digestion tube is rinsed with nitric acid solution three times to ensure that all the samples are dissolved and transferred into the solution.
7. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S5, a 50 ml volumetric flask is used, and the nitric acid solution is added dropwise to the scale line until the lowest point of the concave liquid surface of the solution is tangent to the scale line. Then, the volumetric flask is capped and the volumetric flask is turned upside down 15-20 times to fully mix the solution.
8. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S6, the concentration range of the standard solution can cover the possible content range of the element in the sample to be tested. Specifically, mixed standard solutions with concentrations of 0.1μg / ml, 0.5μg / ml, 1.0μg / ml, 5.0μg / ml, and 10.0μg / ml are prepared. During the preparation process, high-precision pipetting equipment is used to accurately measure the standard stock solution and diluent to ensure the accuracy of the standard solution concentration.
9. A standardized high-purity quartz sand sample pretreatment and element detection method according to claim 8, characterized in that: In step S6, the prepared mixed standard series working liquid is sequentially introduced into the inductively coupled plasma emission spectrometer, and the measurement is performed according to a pump speed of 12 rpm, a power of 1.2 kW, a nebulizer flow rate of 0.7 L / min, a plasma gas flow rate of 12.0 L / min, and an auxiliary gas flow rate of 1 L / min; the characteristic spectral line intensity of each element in each standard solution is recorded, and the standard solution concentration is used as the horizontal axis and the characteristic spectral line intensity is used as the vertical axis. The standard curve is drawn using the instrument's built-in data processing software or Origin to obtain the linear relationship equation between the element concentration and the characteristic spectral line intensity.
10. The standardized high-purity quartz sand sample pretreatment and element detection method according to claim 1, characterized in that: In step S7, during the measurement, the instrument automatically atomizes the sample solution, which enters the plasma in the form of an aerosol. In the high temperature and inert atmosphere, it is fully evaporated, atomized, ionized, and excited, emitting characteristic spectral lines of the elements contained therein. The intensity of the characteristic spectral lines of each element in the sample solution is then recorded. According to the linear relationship equation of the standard curve, the characteristic spectral line intensity of each element in the sample solution is substituted into the equation to calculate the concentration of the corresponding element in the sample. Combined with the weighed mass and constant volume of the sample, the content of each element impurity in the quartz sand is further calculated to complete the qualitative and quantitative analysis of the elements in the quartz sand sample. At the same time, the experimental data is verified for repeatability and accuracy to ensure the reliability of the test results.