This article summarized the sources of endogenous inclusions and exogenous inclusions in detail.The inclusions were classified according to the morphology,composition,deformability and size.The influences of inclusions on the fatigue performance,strength,elongation performance,cutting performance,corrosion property,welding performance,and hydrogen induced cracking of steel were elaborated.Several two-dimensional and three-dimensional detection methods of inclusions were systemically discussed.The extraction methods and detection instruments for various inclusions as well as the removal methods were introduced.

Municipal solid waste incineration fly ash contains harmful substances such as heavy metals and dioxins (PCDD/Fs), so it is classified as hazardous waste. The common disposal method of fly ash is sanitary landfilling after solidification/stabilization treatment. However, this method occupies a large amount of land resources and poses a risk of secondary pollution, which cannot meet the requirements of urban sustainable development. The incineration fly ash is rich in effective mineral components such as CaCO₃, SiO₂, and Al₂O₃. With the rapid development of waste incineration technologies, resource utilization has become an important development trend. In this paper, the formation process, basic composition, and typical physical and chemical properties of incineration fly ash were systematically introduced. The main sources and migration and transformation mechanisms of heavy metals in fly ash were analyzed. Then the formation pathways of PCDD/Fs in fly ash were discussed. The differences in pollutant contents in fly ash across different regions and seasons were compared. Finally, the progresses on representative resource utilization disposal technologies and heavy metal separation-extraction technologies were summarized based on the main components of fly ash.

The top-blown furnace smelting slag in copper smelting is a kind of slag containing high content lead and various impurities.In this paper,a method for the determination of lead content in top-blown furnace smelting slag by precipitation separation-EDTA back titration combined with inductively coupled plasma atomic emission spectrometry(ICP-AES) was established.The sample was dissolved with saturated nitric acid solution of potassium chlorate and ammonium hydrogen fluoride.15 mL of sulfuric acid (1+1) was used to precipitate lead ion and barium ion in the solution,achieving the separation from zinc,iron,calcium,copper and aluminum.5 mL of hydrogen bromide was added to volatilize arsenic and antimony in the solution.Excessive EDTA standard titration solution and 5 mL of ammonia were added to the lead-barium sulfate double salt precipitate. The double salt precipitate was dissolved by heating and boiling in the ammonia medium. Hydrochloric acid(1+1) and 30 mL of acetic acid-sodium acetate buffer solution was added,and the pH of solution was adjusted to 5.5.The solution was heated to slightly boiling to fully complex Pb-EDTA and Ba-EDTA.The separation of lead and barium could be achieved due to the stability difference of complex.5 mL of mercaptoacetic acid(1+99) and 0.1 g of ascorbic acid were added to mask bismuth and iron,respectively.Xylenol orange was added as the indicator.Lead acetate solution was used to titrate the residual EDTA standard titration solution and replace the barium ion complexed with EDTA.The dosage of lead acetate solution was appropriately excessive.Then the excessive lead acetate was titrated with EDTA standard titration solution to calculate the lead content. The lead content in the filtrate was determined by ICP-AES to correct the results.The content of lead in copper smelting top-blown furnace smelting slag was determined according to the experimental method,and the relative standard deviations(RSD,n=11) were 0.24% and 0.29%.The relative error of determination results was -0.092%-0.042% for the simulated samples,which could meet the requirements of process production analysis.

In this paper, a precise registration method for three-dimensional reconstruction of continuous slice images for focused ion beam-scanning electron microscope (FIB-SEM) was proposed. GH4096 polycrystalline high temperature was selected as an example. The sample surface for three-dimensional reconstruction area was etched with the focused ion beam to form a groove, and a specific preset registration marking line was set. The groove of the etched registration marking line was filled with Pt, and a protective layer of Pt was deposited on the surface area of the sample according to the requirements of three-dimensional reconstruction. The microstructure of the material was subsequently characterized according to the normal three-dimensional reconstruction process. Through the preset registration marking lines on the surface of three-dimensional reconstructed area, the accurate and clear feature points could be obtained on all the slice images during continuous slicing, which could be used for the registration of three-dimensional reconstructed images and the measurement of the spacing between neighboring slices, thus improving the accuracy and efficiency of the image registration. Meanwhile, a new method for accurate registration of FIB-SEM three-dimensional reconstruction images was formed by combining the sum of squared differences (SSD) algorithm of the three-dimensional reconstruction software, based on the specific registration marking settings proposed in this paper. The proposed method overcame the problem of jagged dislocations in the usual registration methods and improved the quality and structural clarity of three-dimensional reconstruction.

The content of silicon dioxide in silica is one of the important parameters that play a crucial role in the application and trading of silica. However, the existing methods for measuring silicon dioxide in silica were time-consuming, and the errors of results are usually large. In this study, 0.30 g of sample was treated by alkali fusion with 5.0 g of sodium peroxide. After leaching with water, it was acidified with hydrochloric acid (1+1). Twice dehydration was conducted with 10 mL of perchloric acid. Then the sample was burned to constant mass. Then hydrofluoric acid was added to react with silicon to form silicon tetrafluoride, which could be removed by volatilization. The content of silicon dioxide could be calculated based on the mass difference before and after adding hydrofluoric acid. The method for determination of silicon dioxide in silica by gravimetric method with alkali fusion was established. The contents of silicon dioxide in standard sample of silica (BH-0122-1) and three silica samples were determined according to the experimental method. The relative standard deviations (RSD, n=11) of determination results were between 0.11% and 0.19%. The measured result of silicon dioxide content in BH-0122-1 was consistent with the standard value.

Trace impurities in high purity lead can significantly affect the product quality, and their contents are essential indicators for determination. In this study, the high purity lead sample was dissolved with nitric acid (1+2). The lead matrix was precipitated with sulfuric acid (1+2) and then separated by centrifugation. Fe was determined in He collision mode (He flow rate at 4.8 mL/min), and other elements were determined in standard mode. Meanwhile, the volume error was corrected by volume correction factors. The analysis method of 13 trace impurities (i.e., magnesium, aluminum, manganese, iron, nickel, copper, zinc, arsenic, silver, cadmium, tin, antimony and bismuth) in high purity lead by inductively coupled plasma mass spectrometry was established. The tests indicated that 5.0 g of sample could be completely dissolved with 25 mL of nitric acid (1+2). When 5.0 mL of sulfuric acid (1+2) was added into solution of 5.0 g lead sample for precipitation separation, about 0.93 mL of sulfuric acid (1+2) was residue in sample solution, and the mass concentration of residual lead was approximately 0.13 mg/mL. Scandium or yttrium was selected as internal standard to correct magnesium, aluminum, iron, manganese, nickel, copper, zinc, arsenic, silver, cadmium, tin and antimony, while rhenium selected as internal standard to correct bismuth. The influence of residual sulfuric acid and lead in solution on the determination could be ignored. The linear correlation coefficients of the calibration curves for each tested element were not less than 0.999 1. The limits of detection of this method were in range of 0.002 6-0.15 ng/mL, and the limits of quantification were in range of 0.000 1-0.005 0 μg/g. The proposed method was applied for the determination of 13 trace impurity elements in high purity lead samples. The relative standard deviations (RSD, n=7) of determination results were between 0.59% and 14%, and the recoveries were between 90% and 110%. The impurity elements in high purity lead samples were determined according to the experimental method and inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the found results of two methods were basically consistent.

The contents of impurities in industrial magnesium hydroxide directly affect the downstream application fields. Therefore, the accurate and rapid determination of impurities is crucial. In this study, the sample was dissolved with nitric acid (1+1). K 766.490 nm, Na 589.592 nm, Ca 317.933 nm, Li 670.784 nm, Fe 259.940 nm, and B 249.773 nm were selected as the analytical lines of potassium, sodium, calcium, lithium, iron, and boron, respectively. The calibration curves were prepared by matrix matching method to eliminate the influence of matrix effect. The contents of potassium, sodium, calcium, lithium, iron, and boron were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method for the determination of six trace impurity elements in industrial magnesium hydroxide was established. The mass concentration of potassium, sodium, calcium, lithium, iron, and boron in range of 0.50-5.00 mg/L showed good linearity to the corresponding emission spectral intensity. The linear correlation coefficients of calibration curves were not less than 0.999 6. The limit of detection of each element in this method was 0.000 02%-0.000 6%, and the limit of quantification was 0.000 08%-0.002 4%. The proposed method was applied for the determination of potassium, sodium, calcium, lithium, iron, and boron in industrial magnesium hydroxide sample. The relative standard deviations (RSD, n=6) of determination results were between 0.80% and 12%, and the recoveries were between 90.8% and 106.5%, which could both meet the requirements of GB/T 32465-2015 Requirement for verification & validation of detection methods and internal quality control on chemical analysis.

Aluminum ash residue has been listed in the National Catalogue of Hazardous Wastes for strict management due to its environmental hazards. However, with its high aluminum content, aluminum ash residue possesses significant recycling value. This paper tracks the latest environmental regulatory requirements for aluminum ash residue. It identifies its main components and environmental hazard characteristics, particularly heavy metal leaching toxicity and Al/AlN reactivity. The environmental risk sources associated with aluminum ash residue are analyzed, and its environmental and health risks are evaluated. The progress in both harmless disposal (including wet, thermal, and combined methods) and resource utilization (primarily in the production of water purification materials, building materials, and refractory materials) of aluminum ash residue is reviewed. Finally, key research directions for developing safe and green resource utilization technologies for aluminum ash residue are proposed, providing technical support for its future effective environmental management.

The development of X-ray fluorescence spectrometry (XRF) has undergone 65 years in China,and the quantity of relevant technical literatures has exceeded 14 000. In 2019, the publication of paper Bibliometric analysis on research trend of X-ray fluorescence spectrometry based on CNKI and the book The literature index of X-ray fluorescence spectrometry analysis in China (1960-2015) opened up the statistical and quantitative research on the X-ray fluorescence spectrometry(XRF) literatures in China.On the basis of above two literatures and referring to the recently published review papers,this paper summarized the basic situation of Chinese XRF literatures from 1960 to 2024 in terms of bibliometric statistics,review papers and monographs(translated works),as well as the development process of technology and new technologies and applications.The section of literature metrology and statistics briefly introduced the types of XRF literatures in China,and focused on the main achievements of statistical research,which mainly included the annual distribution of total number of literatures,the overall distribution of journal literatures and the top 10 journals with the largest number of literatures.The section of paper review compiled 226 various review papers published over a span of 65 years from 1960 to 2024.The papers were reviewed according to the categorization of comprehensive reviews,annual reviews,and thematic reviews.The thematic reviews included the instrument (devices) and core components,software and sample preparation techniques,advancements in various application fields.The evaluations of these advancements included geological sample analysis,metallurgy and non-ferrous metals,environment and materials science,agriculture,food, and biomedicine,petrochemicals and process analysis,scientific archaeology and criminal investigation,precious metal jewelry and gemstones testing,and standard methods.The section of specialized(translated) works collected 31 specialized(translated) works officially published in China since the development of X-ray fluorescence spectrometry analysis,and provided a brief introduction by category.

Rapid and accurate determination of metallogenic elements in polymetallic ores is of great significance to the development and utilization of mineral resources. During the simultaneous determination of multi-elements in polymetallic ores, three elements (i.e., tin, tungsten and molybdenum) are hardly decomposed by the ordinary acid dissolution method. In addition, the silver content is low and the linear range is narrow, so it is difficult to provide a reasonable optimization scheme to meet the needs of simultaneous determination of multiple elements.In this study, the polymetallic ore sample was treated by microwave digestion in hydrochloric acid-nitric acid-hydrofluoric acid system. The contents of nine metallogenic elements (including copper, lead, zinc, cobalt, nickel, silver, tungsten, molybdenum and tin) in polymetallic ore sample were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The correlation coefficients of calibration curves of elements were not less than 0.999 7. The limits of detection in this method were between 0.000 3% and 0.007% (0.4 μg/g for silver). Six national first-class reference materials of polymetallic ores were determined according to the experimental method. The relative standard deviations (RSD, n=6) of determination results for most elements were between 0.42%-6.5%, and the determination results for most elements were within the error range of the identified values. The contents of nine elements in polymetallic ore were determined according to the experimental method and compared with the national standard methods. The results were consistent.

The analysis of major and minor components in iron ore usually adopts X-ray fluorescence spectrometry(XRF) with fusion sample preparation.In this study,the mixture of Li₂B₄O₇-LiBO₂ (m(Li₂B₄O₇)∶m(LiBO₂)=67∶33) was selected as the flux.0.5 mL of 400 g/L LiBr-400 g/L LiNO₃ was added as the demolding-oxidation mixed reagent.The sample fusion temperature was 1 050 ℃ and the fusion time was 15 min to prepare the glass melt.The contents of 20 components in iron ore (including total iron,silicon dioxide,manganese oxide,phosphorus,sulfur,calcium oxide,magnesium oxide,aluminum oxide,titanium oxide,potassium oxide,sodium oxide,vanadic oxide,chromium,nickel,copper,lead,arsenic,zinc,tin,and barium oxide) were determined by XRF. The certified reference materials or reference materials of tungsten-tin-bismuth ore,tin-lead-copper ore and iron ore as well as artificially synthesized calibration sample series containing copper,lead,arsenic,zinc,and tin were selected to prepare the calibration curves by the empirical coefficient method. The spectral line overlapping correction,matrix correction and internal standard correction were conducted in sequence for the calibration curves. The fitting of calibration curves was good for each component. The contents of 20 components in three iron ore samples were determined according to the experimental method,and the relative standard deviations (RSD,n=11) of determination results were not more than 7.9%. The contents of 20 components in three standard samples and two actual samples of iron ore were determined according to the experimental method,and the found results were consistent with the certified/reference values (determined by national standard methods).

This study established a method for identifying the solid waste attributes of imported aluminum scrap claimed as “Recycled Casting Aluminum Alloy Raw Materials”. A combination of techniques was employed, including visual inspection, ultra-depth-of-field microscopy for microstructural morphology, inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray fluorescence spectrometry (XRF), and X-ray diffraction (XRD) for compositional, phase, and characteristic element analysis (e.g., lithium, nickel, cobalt). Residual carbon content was measured using an infrared carbon-sulfur analyzer, and the suitability of the sample for direct use as high-quality recycled aluminum feedstock was evaluated via a high-frequency melting furnace. Results showed that the sample consisted of fine gray-white particles. Under microscopy, the aluminum scrap exhibited a wrinkled morphology with numerous black granular inclusions. After sieving through a 120-mesh sieve, XRF revealed a significant decrease in aluminum content in the fine fraction, along with synchronous increases in nickel, cobalt, manganese, and copper. ICP-AES further confirmed the abundance of copper, nickel, cobalt, manganese, and lithium in the sieved fraction. XRD and infrared carbon-sulfur analysis detected lithium nickel cobalt manganese oxide and a small amount of carbon in the sample. During high-frequency melting, the sample produced intense flashing and left substantial residue, with a metal recovery rate below 30% and failure to form liquid metal. These characteristics neither comply with the quality requirements for aluminum scrap stipulated in GB/T 38472-2023 of Recycled Casting Aluminum Alloy Raw Materials nor align with those of conventional machined aluminum scraps. The elemental composition and phase characteristics are consistent with the properties of recycled lithium battery cathode materials. Based on the analysis of the recycling process for aluminum foil current collectors from ternary lithium battery cathodes and in accordance with GB 34330-2017 of General Principles for Identification of Solid Waste Attributes, the sample is identified as solid waste derived from recycled aluminum scrap of ternary lithium battery cathode materials.

The accurate determination of titanium carbide content in titanium carbide slag(titanium carbide) plays a key role in the guidance of carbonization production process.In this study,the hydrochloric acid-sulfuric acid-hydrofluoric acid system was used to selectively dissolve titanium oxide,realizing the rapid separation of titanium oxide and titanium carbide phases in titanium carbide slag.After separation,the residue and filter paper were ashed and burned at 600-700 ℃ for 20 min,and then burned at 1 100 ℃ for 2-3 min.Lithium tetraborate-lithium carbonate was selected as the flux,and lithium bromide was selected as the release agent.The sample was fused at 1 100 ℃ for 20 min to prepare the transparent bead.A method for the determination of titanium carbide in titanium carbide slag by X-ray fluorescence spectrometry with fusion sample preparation was established.After the titanium carbide slag sample was separated using the hydrochloric acid-sulfuric acid-hydrofluoric acid system,titanium carbide in the residue could be converted to titanium dioxide through burning at high temperature.Therefore,nine samples of spectrally pure titanium dioxide(5.0-80.0 mg) were used to draw the calibration curve.The linear correlation coefficient was r=0.999 98,and the determination range of titanium dioxide was 1.25%-20.0%.The contents of titanium carbide in two titanium carbide slag samples were determined according to the experimental method,and the relative standard deviations(RSD,n=6) of the determination results were not more than 0.5%.Three titanium carbide slag samples were selected and determined according to the experimental method.Then the high-purity titanium carbide was added for the spiked recovery test.The recoveries were between 97% and 102%.The contents of titanium carbide in titanium carbide slag samples were determined by the experimental method and spectrophotometry respectively,and the results were consistent.

When the electron probe micro analyzer(EPMA) is used for the quantitative analysis of oxide minerals,the Oxide ZAF correction method (without measurement of O element K factor, abbreviated as Oxide ZAF method) is usually used instead of Metal ZAF method(measurement of O element K factor).Although the results are very reliable,it is not consistent with the previous understanding of ZAF correction(all elements are required to participate in the analysis especially for the high-content elements).In order to have a deeper understanding on the correction process of Oxide ZAF,and so that the most suitable correction method can be selected for the quantitative analysis of different substances in the future,the ferromagnesia olivine[w(O)=44.00%,w(Mg)=31.41%,w(Fe)=6.27%,w(Si)=18.35%,w(Ni)=0.33%,w(Mn)=0.06%] was taken as the sample in this study,and the two correction methods were used for quantitative analysis and comparison.Then the iterative calculation process was shown by the ZAF simulation program,and the important theory that the K factor of O element in Oxide ZAF method was not measured directly,but it still participated in ZAF correction was verified.In addition,the application range of Oxide ZAF method was discussed,that was,the sample should strictly follow the oxide formula and the chemical valence state of each cation was single.A more widely used CAL quantitative analysis method was proposed.This method could be used for the quantitative analysis of carbonate,water-containing samples and minerals containing F,Cl,OH and Li and Be elements.

In research and development of high temperature alloy,the accurate characterization of global composition distribution characteristics of materials is of great significance for process optimization,service performance improvement,and material quality monitoring or evaluation.In this study,the global and regional composition distribution of GH4169 high temperature alloy bar sample was characterized using original position statistic distribution analysis system for ultra large metal components.Various key parameters were systematically optimized,and the optimal experimental conditions were finally determined as follows:the capacitance parameter was 0.10,the spark excitation frequency was 400 Hz,the scanning speed was 45 mm/min,the processing rotational speed was 250 r/min,and the electrode distance was 4.0 mm.A characterization and evaluation model for segregation degree of GH4169 high temperature alloy was established.The results showed that the selected GH4169 high temperature alloy sample had no defects in the central area.The product segregation could meet the standard range according to the standard sampling area evaluation.The global segregation analysis data indicated that on the whole,the uniformity of each element was good,but there was still room for improvement in the uniformity of Fe.The proposed method had guiding significance for the optimization of GH4169 high temperature alloy production process as well as the research and development of high-performance materials.

The accurate determination of high field strength elements(HFSE) in geochemical exploration samples such as hafnium(Hf),niobium(Nb),tantalum(Ta) and zirconium(Zr) is the important prerequisite for achieving information on the diagenetic evolution of rocks.In this study,the solid melt digestion method using ammonium fluoride was combined with the sensitization technology using triethylamine as the matrix modifier.The method for the determination of Hf,Nb,Ta and Zr in geochemical exploration sample by inductively coupled plasma mass spectrometry(ICP-MS) was established.The pretreatment of sample had two steps.Firstly,the sample was melted with ammonium fluoride at 240 ℃ for 2.5 h,where the mass ratio of ammonium fluoride and sample was 6∶1.Then,certain amount of perchloric acid were added to dissolve the sample.After evaporation,the nitric acid and a small amount of hydrochloric acid was added for redissolution-evaporation,realizing the complete digestion of sample.After evaporating the solution to almost dryness,the residue was redissolved with nitric acid.2%(volume fraction,the same below) nitric acid-0.2% hydrofluoric acid was added as the determination medium to avoid the hydrolysis or polymerization of Nb and Ta.10% triethylamine was used as matrix modifier for determination.The normalized signal intensity of Hf,Nb,Ta and Zr increased by 1.8,12.5,2.9 and 3.3 times,respectively.The linear correlation coefficients of calibration curves of elements were all higher than 0.999.The limits of detection of method were between 2.23 and 22.7 μg/kg,and the limits of quantification were between 7.43 and 75.8 μg/kg.The contents of Hf,Nb,Ta and Zr in certified reference materials of soil,rock and stream sediment were analyzed according to the experimental method.Each sample was determined for 12 times in parallel.The results showed that the measured values were basically consistent with the certified values.The logarithmic deviations(ΔlgC) between measurement average and standard value were all less than 0.05.The relative errors(RE) were between -1.7% and 8.0%,and relative standard deviations(RSDs,n=12) were between 1.7% and 9.0%,which could meet the accuracy requirements specified in industry standard DZ/T 0167-2006.Two soil samples from northern area of Henan were determined according to the experimental method and standard method,i.e.,hydrofluoric acid-nitric acid closed dissolution-ICP-MS in GB/T 14506.30-2010.Each sample was determined for 6 times in parallel.The results showed that the measurement values of two methods were basically consistent. The RSDs of analytical results of experimental method were between 1.5% and 6.1%.

Laser-induced breakdown spectroscopy (LIBS) system is mostly used in the field of material identification. There are few studies on the fine classification of scrap stainless steel in this field. In addition, the existing LIBS system is sensitive to material height changes and cannot adapt to the classification of scrap stainless steel with variable sizes. At present, there is a lack of intelligent detection and classification equipment in scrap stainless steel industry in China, which has led to the downgrading of a large number of stainless steel scraps. Therefore, it is necessary to further study the use of LIBS equipment for fine sorting of scrap stainless steel by brand. In this paper, the existing LIBS system was improved by using a reflective light receiving optical path to solve the problems of light path obstruction and light path deviation during classification and detection of scrap stainless steel due to the various shapes and sizes of scrap stainless steel. The system could collect the spectral signals of samples within the range of ±3 cm in height. In view of the demand for rapid sorting of scrap stainless steel, a random forest (RF) classification model based on the sparrow search algorithm (SSA) was proposed. The improved system was used to collect spectral data, and the SSA-RF model was imported for training and verification of the classification results. The results showed that the average recognition accuracy of the SSA-RF classification model was 98.31%, and the average recognition time was 0.016 s. The combination of the improved LIBS system and the SSA-RF algorithm could realize the classification of scrap stainless steel of variable sizes with high efficiency and stability, providing a reference method for the classification of scrap stainless steel.

In order to detect gold in ore quickly, accurately and nondestructively, a physical model for the direct determination of gold by energy dispersive X-ray fluorescence spectrometry (EDXRF) was established by GEANT4 program and Monte Carlo method. The trajectory of particles going through three stages in the whole optical path, i.e., electron targeting, filter and sample excitation, was simulated. The counting effects and X-ray fluorescence spectra at different stages were analyzed. Monte Carlo method was used to simulate different parameters of various key components in EDXRF including optical tube target, tube voltage and filter. A simulation method for direct and rapid determination of gold in ores was established, which further broadened the detection means of gold and improved the detection efficiency. The simulation results using GEANT4 software showed that the high efficiency excitation of gold could be achieved under the following conditions: molybdenum target was selected as the anode target, the tube voltage was 40 kV, and the filter material was aluminum. The test platform was set up to test the different optical tube voltages and filters with different materials. The variation trend of testing results was basically consistent with the simulation results, indicating that the established simulation method could provide a design basis for the follow-up research gold determination by X-ray fluorescence spectrometry (XRF).

This paper systematically investigated the differences among the standard curve method,the certified reference material(CRM) curve method,and the standard addition method in inductively coupled plasma atomic emission spectrometry(ICP-AES) analysis,as well as their requirements for blank solutions.By deconstructing the spectral intensity composition of the calibration,sample,and blank solutions,the following conclusions were drawn:1)For the calibration curve based on the concentration of the added standard solution versus the spectral intensity,its intercept comprised the blank value,the content of matrix elements,and the fitting error.The measurement results required compensation for the over-deducted analyte content in the matrix metal.For the calibration curve based on the sum of the standard solution concentration and the matrix element content versus the spectral intensity,its intercept reflected only the blank value and fitting error,and the measurement results were final.No dedicated blank solution preparation was necessary in both cases.2)In the CRM curve method,the intercept encompassed the blank,CRM uncertainty,and fitting error.The test results were final,blank solution preparation was unnecessary,and abnormalities could not be judged solely by the blank value.3)The standard addition method required a blank solution and had the limitation of being unable to eliminate spectral interference from coexisting elements completely.4)When the calibration and sample solutions were prepared in separate batches,deducting their respective reagent blanks before calibration effectively eliminated blank variations caused by reagent batch differences.This approach solved the problem of reusing calibration solutions and yielded accurate test results.The study also showed that a full-process blank should be used when the matrix effect is minor,whereas a matrix metal blank solution should be employed when the matrix effect is strong (with results compensation).Moreover,the content of the analyte in the blank solution must be strictly controlled below half of the quantification limit to ensure accurate determination of elements at that level.

The comprehensive utilization of vanadium ore resources requires the accurate determination of its components.The vanadium ore resources in China are abundant,which mainly exist in vanadium-titanium magnetite and stone coal vanadium ore.The vanadium-titanium magnetite is a kind of ore which is hardly decomposed,while the stone coal vanadium ore contains high content of carbon or organic matters,so the decomposition of sample is usually incomplete.Moreover,vanadium and titanium are easily hydrolyzed.In this study,the sample was treated by microwave digestion in nitric acid-hydrofluoric acid system.V 310.230 nm,Ti 334.940 nm,Fe 239.562 nm,Al 396.153 nm,Co 228.616 nm,P 214.914 nm,Cu 327.393 nm and Mn 259.372 nm were selected as the analytical line of vanadium,titanium,iron,aluminum,cobalt,phosphorus,copper,and manganese,respectively.The method for determination of vanadium and coexisting(associated) elements(including iron,titanium,aluminum,cobalt,phosphorus,copper and manganese) in vanadium ore by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. The medium for test solution was 5%(volume fraction)hydrochloric acid in experiments to prevent the hydrolysis of vanadium and titanium.The linear correlation coefficients of calibration curves of elements were all higher than 0.999.The limit of detection of this method was in range of 20-158 μg/g.The proposed method was applied for the determination of vanadium,titanium,iron,aluminum,cobalt,phosphorus,copper,and manganese contents in certified reference materials (GBW07224 and GBW07875),and the relative standard deviations (RSD, n=12) of determination results were between 0.2% and 6.0%,which could meet the requirements of DZ/T 0130 The specification of testing quality management for geological laboratories.The determination results were basically consistent with the certified values,and the relative error(RE) was between -6.72% and 11.00%.GBW07877 and one vanadium ore sample were selected and determined according to the experimental method and ICP-AES after high-pressure closed acid dissolution.The results showed that the measurement values of two methods were consistent.

Large non-deformable inclusions are one of the main causes of wire breakage for tire cord steels during drawing and stranding.Therefore,it is necessary to study the types and evolution law of inclusions in the tire cord steel.In the paper,the type and morphological evolution law of inclusions in 82A tire cord steel from billet to wire rod were investigated by the means of focused ion beam-electron beam scanning electron microscopy(FIB-SEM),energy disperse spectroscopy(EDS) and three-dimensional reconstruction software.The results showed that the main types of inclusions were MnS,MnS-SiO₂ and MnS-SiO₂-CaMgAlMnSiO.The planar morphology of MnS inclusions in the billet were mostly elliptical or nearly round,while the morphology of MnS in the wire rod became elongated strip shape.The planar morphology of MnS-SiO₂ inclusions in the billet had the core of nearly round SiO₂, and the outer layer was wrapped MnS.In the wire rod,its morphology was still maintained in the nearly round SiO₂ as the core,but the MnS wrapped on outer layer became long stripes,showing the overall appearance of "eye-shaped".The planar morphology of MnS-SiO₂-CaMgAlMnSiO inclusions in the billet was based on SiO₂ as the core,which was wrapped with composite oxides enriched in Ca,Mg,Al,Mn,Si and O,and the outermost layer was MnS.In wire rod,the deformation of SiO₂ was not obvious,and composite oxides became fragmented. Moreover,MnS was elongated,and the whole morphology showed string-like distribution along the drawing direction.The study on the evolution law of inclusions type and morphology provided process control direction for the analysis of inclusions harm and the development of high-end tire cord steel.

It is difficult to determine the content of silver and cadmium in soil directly and accurately by inductively coupled plasma mass spectrometry (ICP-MS) due to the mass spectral interference of zirconium and molybdenum.In this study,the soil samples were treated by rapid digestion method followed by zirconium separation with ammonia precipitation.¹⁰⁷Ag and ¹¹¹Cd were used as analytical isotopes and the interference of ⁹⁵Mo¹⁶O⁺ with the determination of ¹¹¹Cd in solution was reduced by collision mode.The method for the determination of silver and cadmium in soil by ICP-MS after rapid digestion and ammonia separation was established.The dosage of ammonia and helium flow rate were optimized.The reference materials and samples of soil were analyzed.The results showed that the limit of detection of silver and cadmium in soil was 0.003 and 0.005 mg/kg,respectively.The determination results of soil reference materials were within the certified value and uncertainty range,and the relative standard deviation(RSD) was 1.3%-8.2% and 2.1%-7.9%,respectively. For soil sample,the determination results of ICP-MS method had no significant difference with those obtained by graphite furnace atomic absorption spectrometry(GFAAS).The proposed method could meet the detection requirements of trace silver and cadmium in soil samples.

The application of intelligent rapid analysis system,which integrated automatic sampling,pneumatic transmission,automatic sample preparation and rapid analysis,in sinter analysis was introduced in this study.A series of comparative experiments were conducted to compare the differences between this automatic system and manual sampling,manual sample preparation,and manual analysis.The experiment results showed that the implementation of the intelligent rapid analysis system confirmed the existence of systematic deviations in the traditional manual sampling,sample preparation and analysis of TFe,SiO₂,CaO,MgO,Al₂O₃,and S in sinter by X-ray fluorescence spectrometry(XRF),with deviation of -0.512%,0.377%,0.550%,-0.092%,-0.195%,and 0.007%,respectively.The F-test values of MgO and Al₂O₃ were both below the critical value,indicating that there was no significant difference in sampling accuracy between two methods.However,the F-test values of TFe,SiO₂,CaO,S contents and basicity were all above the critical value,indicating that the sampling accuracy of the intelligent rapid separation system was better than that of manual sampling.In addition,it could be concluded that there was no significant difference between the methods based on the P value of the t test between pressed powder pellet and high temperature fusion sample preparation,as well as the P value of the t test between manual and automatic pressed powder pellet.Of particular importance,the daytime fluctuations(standard deviation) of content of TFe,SiO₂,CaO,S,and alkalinity in automatic sampling decreased by 43.35%,49.11%,48.96%,48.76%,and 38.68% compared to manual sampling,respectively.By adopting the intelligent rapid analysis system,not only the material quality management process could be optimized to improve the sampling representativeness and sample preparation efficiency,but also the accuracy and reliability of data could be significantly enhanced.

With the development of new technologies,some novel ferroboron alloys with different properties are developed.The contents of different elements in ferroboron determines the properties of alloys.At present,the alkali melting method or acid dissolution slag method is usually used for pretreatment of ferroboron sample before detection of elements.Although the sample can be dissolved completely and the simultaneous determination can be achieved,these methods are cumbersome if some elements are determined separately.Therefore,it is very important to choose the appropriate decomposition method for different elements in consideration of the perspective of economy and time cost.In this study,the certified reference materials(CRM) of ferroboron were digested using various decomposition methods including direct acid dissolution method(nitric acid+hydrofluoric acid+perchloric acid),microwave digestion method,acid dissolution slag method and alkali melting method.Then, the contents of chromium,nickel,vanadium,copper,titanium,manganese,aluminum and phosphorus in the digestion solution using different decomposition methods were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The results showed that there were few black insoluble matters in the solution when the direct acid dissolution and microwave digestion were used,but the accurate determination of chromium,nickel,vanadium,copper,titanium and manganese was not affected.However,the determination results of aluminum and phosphorus were relatively lower than the certified values or standard values,especially for phosphorus.It indicated that the degree of dissolution of the sample had significant influence on the accurate determination of aluminum and phosphorus.Therefore,for the determination of chromium,nickel,vanadium,copper,titanium and manganese,the four dissolution methods above were all acceptable.However,for the determination of aluminum and phosphorus,the sample must be completely dissolved using acid dissolution slag method and alkali melting method to obtain accurate results.

The chemical composition inspection of carbon steel and middle-low alloy steel thin plate plays a key role in the quality control of outgoing products and the development of new products.In experiments,the content of 13 elements in carbon steel and middle-low alloy steel thin plates,including C,Si,Mn,P,S,Cr,Ni,Cu,Al,Nb,V,Ti and N,were determined by spark discharge atomic emission spectrometry.The effects of sample preparation method, spectral excitation limit sample thickness and sample flatness were investigated,and the use of specific sample fixtures was also discussed.It was found that the sample with a thickness less than 0.30 mm should be polished with manual sandpaper,while sample with a thickness of 0.30-2.00 mm should be polished with a sand belt machine.The sample with a thickness less than 0.20 mm was not suitable for the determination by spark discharge atomic emission spectrometry.After using a special fixture and pressure block combination,the back of the sample almost showed no indentation or color change to blue.According to the experimental method,the carbon steel and middle-low alloy steel thin plate samples with different thicknesses were tested.The results showed that except for ultra-low carbon,sulfur and nitrogen,the relative standard deviations (RSD,n=10) of determination results of other elements were all less than 5%.The content of 13 elements in carbon steel and middle-low alloy steel thin plate samples with different thickness was determined according to the experimental method and national standard method (where C and S were determined according to GB/T 20123-2006,N was determined according to GB/T 20124-2006,and other elements were determined according to GB/T 20125-2006).The result showed that the determination values of two methods were consistent.The proposed method effectively solved the problem in the national standard GB/T 4336-2016 that samples with a thickness less than 2 mm could not be directly analyzed using spark discharge atomic emission spectrometry,and it expanded the thickness of carbon steel and middle-low alloy steel thin plate samples in direct inspection by spark discharge atomic emission spectrometry.

The mineralogical characteristics of the integrated process from blast furnace slag to carbide slag to chlorinated residue, along with the occurrence and transformation behavior of titanium, were systematically studied using the AMICS automatic mineral analysis system. Results indicate that titanium in blast furnace slag primarily resides in perovskite (51.76%), titanium-rich pyroxene (26.96%), and titanian diopside (21.17%). Mineral crystallization followed the sequence: metallic iron > perovskite > titanium-rich pyroxene > titanian diopside. During high-temperature carbonization, titanium in perovskite transformed into titanium carbide. Titanium carbide particles (0.5-5 μm) were encapsulated within titanian augite, forming titanium carbide coatings surrounding metallic iron. The low-temperature chlorination process demonstrated significant selectivity: successful chlorination of most titanium carbide increased the titanian augite content in the residue to 94.90%(mass fraction, the same below). Unreacted titanium carbide (3.38%) concentrated within the core zones of titanian augite grains, and zones with well-developed fractures exhibited higher chlorination completeness. These findings elucidate the phase transformation mechanism of titanium during blast furnace slag valorization, providing a theoretical basis for enhancing titanium recycling efficiency.

The primary γ′ phase is the main strengthening phase that determines the properties of superalloys, so it is of great significance to analyze the size and volume fraction of the primary γ′ phase. This study focused on the microstructure characteristics of the primary γ′ phase in GH4096 superalloy. The three-dimensional morphology of the primary γ′ phase was accurately characterized by focused ion beam (FIB) three-dimensional reconstruction technology. The two-dimensional large-field characterization was conducted using high-throughput scanning electron microscopy. It was found that the primary γ′ phase in the three-dimensional slice had several interference factors such as irregular shape, similar gray level to the background, and containing twin crystals inside some crystalline grains, which was not easy to identify. Therefore, the artificial intelligence technology was introduced to rapidly identify the primary γ′ phase in images of three-dimensional slice, and the three-dimensional visual characterization was finally realized. The three-dimensional characterization and two-dimensional characterization were compared, and the results showed that the size of the primary γ′ phase was concentrated above 1.5 μm in two methods. The cumulative volume fraction and area fraction were basically consistent, i.e., 14.915% and 14.925%, respectively. Compared to the conventional two-dimensional image analysis, the three-dimensional characterization could provide more information to comprehensively describe the microstructure of the primary γ′ phase, and the spatial arrangement of primary γ′ phase could be displayed more clearly.

The quality of glass products is directly affected by the content of ferric oxide (Fe₂O₃) in the silicon glass raw materials. In this study, the method for determination of Fe₂O₃ in silicon glass raw materials by X-ray fluorescence spectrometry with powder pellet preparation was investigated to solve the problems of traditional chemical analysis methods such as long analysis time, complex operation and high cost. The pellet preparation conditions, including the particle size, preparation pressure, pressing time, and the type and ratio of binder, were focused on. A series of calibration samples were self-prepared with Fe₂O₃ and quartz sand to establish the calibration curve. The experimental results indicated that the pellet exhibited good moldability and a smooth, flat surface when it was prepared under the following conditions: 10% microcrystalline cellulose was added into sample with particle size of 75 μm (D90); the mixture was pressed at 15 MPa for 20 s. The linear correlation coefficient of calibration curve for Fe₂O₃ was 0.999 9. The limit of detection of Fe₂O₃ was 0.000 51%, and the determination range of this method was from 0.001 5% to 0.10%. The contents of Fe₂O₃ in two samples of silicon glass raw materials were determined according to the experimental method. The relative standard deviation (RSD, n=7) of determination results was 0.87% and 1.1%, respectively. One certified reference material for component analysis of silicon sandstone and six actual samples of silicon glass raw material were selected. The contents of Fe₂O₃ were determined according to the experimental method and other methods (phenanthroline spectrophotometry and atomic absorption spectrometry). The results showed that the measured value of certified reference material was consistent with the certified value, and the determination results of actual samples by two methods were consistent. The propose method for determination of Fe₂O₃ in silicon glass raw materials by XRF with powder pellet preparation could reduce the detection period, save the testing time and economic cost. Moreover, it was easy to operate. The expensive accessories or large amounts of reagents were not required. In addition, no waste liquid was produced. Thereby the proposed method exhibited significant green advantages.

For the determination of carbon content in titanium alloy,the sample is usually treated by high-temperature combustion in an oxygen flow to release carbon in the form of carbon dioxide for detection.At present,the most mature method is high-frequency combustion coupled with infrared absorption analysis.However,there are still few systematic investigations on the types of flux and sample mass using this method for carbon determination in titanium alloy.In this study,three different brands of titanium alloys (TA2, TB13, and TC4) were selected.The effect of sample mass,flux mass,flux type,and the stacking order of flux and sample in the crucible on the melting efficiency of titanium alloy and the measurement results of carbon during the determination of carbon content in titanium alloy by high frequency combustion infrared absorption were systematically explored using orthogonal experimental method.The experimental results demonstrated that the sample mass exerted the most significant influence on the determination results of carbon, and the optimal sample mass was 0.2 g.For the type of flux,the melting effect was good when pure copper or copper+tin+iron (m_Cu∶m_Sn∶m_Fe=2∶1∶1) was selected as the flux.The combustion was complete without splashing.The peak shape was normally distributed without tailing.As the flux was mixed uniformly with the sample,the carbon release efficiency was optimal,and the measured results were most close to the reference values.For the flux mass,when the dosage of flux was 2.1 g,the release rate of carbon was the highest,and the requirements of GB/T 4698.14-2011 could be met.The content of carbon in titanium alloy certified reference material GBW(E)020180 was determined according to the optimized experimental method,and the relative standard deviation(RSD,n=11) was 0.53%.This study provided an optimized protocol for high-frequency combustion infrared absorption analysis of carbon in titanium alloy, and it had significant practical application value.

The solid waste attributes of two samples declared as "lead concentrate powder" and "lead-zinc ore" were identified and analyzed. Based on characteristics such as element content, phase composition, microscopic morphology, and particle size distribution, it was concluded that the two samples were lead-containing fume and lead pyrometallurgical slag, respectively. The main elements in the "lead concentrate powder" sample were lead, sulfur, zinc, tin, chlorine and copper, and the main phases were lead sulfate, basic lead chloride and zinc stannate. The particle size was very fine, and the microscopic morphology consisted of extremely fine spherical particle aggregates. These features are inconsistent with the characteristics of common lead ores, indicating it is lead-containing fume produced during pollution control processes. The main elements in the "lead-zinc ore" sample were silicon, zinc, iron, calcium, aluminum and lead, and its main phases were hardystonite, willemite, calcium zinc silicate and gatena. Its microscopic morphology showed a honeycomb-like microporous structure, consistent with lead pyrometallurgical slag. According to GB 34330-2017, both samples were identified as solid wastes.

Yttrium,neodymium and gadolinium are important alloying elements of magnesium alloy,and greatly affect the properties of magnesium alloy.Therefore,the accurate determination and evaluation of their contents is of great importance.In this study,the problem of sample segregation was solved by equally spaced multipoint drilling and sampling.The sample was dissolved with HCl(1+1).Y 371.029 mn,Nd 430.358 nm and Gd 335.047 nm were selected as analysis lines for yttrium,neodymium and gadolinium,respectively.The matrix effect and interference of coexisting elements were investigated,and the interference among zirconium,neodymium and gadolinium was eliminated using interference coefficient correction method.The method for the determination of yttrium,neodymium and gadolinium in rare earth magnesium alloy by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established.The linear correlation coefficients of calibration curves for yttrium,neodymium and gadolinium in linear range all reach 0.999 9.The limit of detection for elements in this method was in range of 0.000 002%-0.000 17%(mass fraction,similarly hereinafter),and the limit of quantification was in range of 0.000 005%-0.000 58%,respectively.The content of yttrium,neodymium and gadolinium in rare earth magnesium alloy samples was determined according to the experimental method,and the relative standard deviation(RSD, n=11) of determination results was 0.86%-6.6%,0.95%-2.4% and 0.82%-5.3% for yttrium,neodymium and gadolinium,respectively.The recovery was 98%-105%,99%-104% and 98%-103%,respectively.

Ferromolybdenum is mainly used as an additive of molybdenum(Mo) in the process of steelmaking.The accurate determination of Mo content is of great significance for steel quality control and commercial settlement.The impurity elements in ferromolybdenum such as Si,Cu and As have certain influence on the steel property.In this study,high-purity iron bead was selected as the flux.The mass ratio of sample to flux was 1∶4.The sample was melted to prepare the mushroom-shaped test blocks by high frequency fusion sample preparation.Then a layer with thickness of 1.50 mm was milled from the surface of test block,and the exposed surface was used as the final testing surface.A series of ferromolybdenum reference materials and artificially synthesized calibration samples were selected to draw the calibration curves.The content of Mo,Si,Cu and As in ferromolybdenum was determined by X-ray fluorescence spectrometry(XRF).The linear correlation coefficients of the calibration curves for each element were all greater than 0.999.The limit of detection for Si,Cu,and As was 11.48-427.7 μg/g.The content of Mo,Si,Cu and As in ferromolybdenum sample was determined according to the experimental method,and the relative standard deviation(RSD, n=11) of the measurement results was less than 10%.The experimental method was applied to the determination of Mo,Si,Cu and As in ferromolybdenum certified reference materials and samples.The determination results of reference materials were consistent with the standard values,and the determination results of samples were consistent with reference values which obtained by standard methods including GB/T 5059.1-2014 (Mo),NACIS/C H147:2019 (Si),GB/T 5059.3-2014(Cu) and NACIS/C H147:2019(As).The errors were all less than the critical difference CD_0.95.

When the inductively coupled plasma atomic emission spectrometry in standard method GB/T 12689.12-2004 is used to determine aluminum and iron in zinc alloy,the chemical pretreatment is time-consuming and the operation is cumbersome.In this study,the surface of zinc alloy sample was prepared using a fully automatic milling machine.The zinc alloy certified reference material/standard sample and nine zinc alloy production samples (1#-9#) where were certified by standard method GB/T 12689.12-2004 were used as calibration sample series to draw the calibration curves.The waiting time for sample analysis was controlled to be 0-5 min.The method for the determination of aluminum and iron in zinc alloy by X-ray fluorescence spectrometry (XRF) was established.The results indicated that the determination coefficient/correlation coefficient of the calibration curves for aluminum and iron were both not less than 0.999 5.The determination ranges for aluminum and iron were 0.117%-0.397% and 0.000 85%-0.023%,respectively.The limits of detection of this method were 7.46 and 4.21 μg/g,respectively.The content of aluminum and iron in three zinc alloy samples was determined according to the experimental method,and relative standard deviations (RSD, n=11) of the results were both less than 5%.The measured results of aluminum and iron in zinc alloy certified reference material/standard sample were consistent with the certified values/standard values.The experimental method and standard method GB/T 12689.12-2004 were used to determine aluminum and iron in zinc alloy production samples,and the absolute error could meet the requirements of the interlaboratory allowable difference in standard method GB/T 12689.12-2004.

Online diagnosis and testing of γ-TiAl components in aircraft engines during processing and manufacturing is an important part for aircraft engine manufacturing and intelligent testing. Due to the fact that laser-induced breakdown spectroscopy(LIBS) technology can only be used to detect the elemental composition of materials,there is a lack of direct judgment on the microstructure of materials.In this study,the identification of γ-TiAl microstructure was realized based on the combination of LIBS with deep learning algorithms.In experiments,γ-TiAl samples were subjected to six different heat treatments to obtain different microstructures under electron microscope.Subsequently,LIBS experiments were conducted on γ-TiAl with different microstructures,and the obtained spectra were denoised through baseline correction and wavelet transform.In order to improve the simplicity and interpretability of the data,principal component analysis(PCA) was used to take the first 32 principal components as the dimensionality reduced data,which were used as the inputs for classification by three deep learning models, i.e.,BP neural network(BP),convolutional neural network(CNN),and long short-term memory neural network(LSTM).Among them,the LSTM model had the best performance with accuracy of 96.04%,while the BP and CNN models also had excellent results,with accuracy of 95.57% and 93.35%, respectively.Meanwhile,the training of three models was completed within 30 s.Therefore,the combination of LIBS and deep learning models could achieve the accurate classification of γ-TiAl with different microstructures,which provided new means and ideas for intelligent detection in industrial production in the future.

Silicon-based ferroalloys are widely used in the steel metallurgy and casting industries as deoxidizers,alloying agents and inoculants.For the scientific guidance of production and application,it is of great significance to accurately and rapidly detect the main and trace alloy components in silicon-based ferroalloys.Due to the advantages of high precision,high sensitivity,accuracy,rapidity and high degree of automation,X-ray fluorescence spectrometry(XRF) analysis has played a crucial role in many fields such as on-site quality control in production,research and development of new materials,exploration of physical and mineral resources,environmental protection and cultural relic identification.As an important analytical method for characterizing the chemical composition and properties of substances,XRF has gradually been deeply studied and widely applied in the composition detection of silicon-based ferroalloys since the 1990s.The author has retrieved that 4 monographs related to the analysis of silicon-based ferroalloys have been compiled by chemical detection technicians in China. 30 classic chemical analysis standard methods and 27 modern instrumental analysis standard methods for silicon-based ferroalloys were studied and formulated.A total of 44 research papers on the analysis of the chemical composition and technology of silicon-based ferroalloys by XRF method have been published in various journals,magazines and national industry conference paper collections,including 21 papers on the analysis of silicon-based ferroalloys by XRF with pressed powder pellet and 23 papers on the analysis of silicon-based ferroalloys by XRF method with fusion sample preparation.The sample preparation technology,the selection of reference materials,the calibration of working curves,the scientific nature of detection data and the application prospects of silicon-based ferroalloys analyzed by XRF were briefly reviewed in this paper. Total 105 articles were cited.

The content of C,Si,P,S,Cr,Mo,Nb,Al,Co,Ti,and Ta in nickel-based superalloy GH4169(hereinafter referred to as GH4169) has an impact on the thermal and mechanical properties of material.Therefore,it is necessary to accurately determine the content of these 11 elements.In this study,the spark discharge atomic emission spectrometry was employed for the determination of above elements in GH4169.The instrument parameters were optimized and the following experimental conditions were finally selected:the argon flushing time was 5 s,the flushing flow rate was 60 L/h,the pre-combustion time was 13 s,the argon analysis flow rate was 60 L/h,and the exposure time of Task 1,Task 2,and Task 3 was 3 s.Pure nickel reference material was selected for the determination of limit of detection.The results showed that the limit of detection of P,S,and Co was less than the lower limit of built-in curve,while the limit of detection of other elements was below 0.003 0%.The certified reference material SRM1249 was selected for the precision testing,and the results showed that the relative standard deviations (RSD) for each element could meet the requirements of the coefficient of variation in GB/T 27417.The certified reference material GH4169 in different batches were selected for the accuracy testing.It was found that the absolutes of the differences between analysis results and certified values were less than the critical difference CD_0.95.The influence of traditional type standardization and virtual type standardization on the analysis results was compared.The results indicated that analysis result of Si had great difference with that obtained by inductively coupled plasma atomic emission spectrometry(ICP-AES) when the certified reference material SRM1249 was used as a type standardized sample to determine GH4169.However,when GH4169 control sample and SRM1249 certified reference material were used as virtual type standardization sample to determine GH4169,the measurement results were consistent with those obtained by ICP-AES and carbon sulfur analyzer.

Superalloys have high alloying degree and complex composition of precipitated phases.The qualitative and quantitative analysis of precipitated phases in superalloys is of great significance for the service evaluation of superalloys.In this paper,the precipitated phases in GH4169 superalloy were extracted and analyzed by electrolytic extraction.The effects of electrolysis parameters,including electric current density,electrolysis time and temperature,on extraction of precipitated phases were investigated by scanning electron microscope(SEM) observation and X-ray diffraction(XRD).The results showed that the ambient temperature could not exceed 20 ℃ when ammonium sulfate-citric acid solution was used as electrolyte,otherwise it would lead to the hydrolysis of nickel.The time of single electrolysis could not be too long,otherwise it would lead to anode precipitation pollution.The optimum electrolysis conditions for extracting the precipitated phases in GH4169 superalloy were obtained as follows:the electrolyte was 10 g/L ammonium sulfate-10 g/L citric acid solution;the time of single electrolysis extraction was not more than 8 h;the current density was about 0.05 A/cm²;the electrolysis temperature was 17-20 ℃.

Molybdenite sample was digested with nitric acid-hydrogen peroxide-sulfuric acid-hydrofluoric acid system in experiments,and the content of molybdenum in molybdenite was determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The results showed that 0.1-0.5 g of sample could be completely dissolved with 5 mL of nitric acid,1 mL of hydrogen peroxide,5 drops of sulfuric acid and 3 mL of hydrofluoric acid.5%(V/V,similarly hereinafter) hydrochloric acid was selected as the testing medium.As the mass concentration of molybdenum was in range of 50.0-3 000 μg/L,the calibration curve exhibited good linearity with correlation coefficient (r) of 0.999 996.The limit of detection was 0.336 μg/g,and the limit of quantification was 1.12 μg/g.The content of molybdenum in five molybdenite samples was determined according to the experimental method,and the relative standard deviation(RSD,n=11) was 0.67%-4.1%.The content of molybdenum in certified reference materials of molybdenum ore (GBW07141) and tungsten ore(GBW07241) and five molybdenite samples was determined by the proposed method and spectrophotometric method in GB/T 14352.2-2010.The determination results of two methods were consistent.The measured results of molybdenum in two certified reference materials were consistent with the certified values.

Wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) is increasingly utilized in environmental monitoring for determining inorganic elements in soil and sediment samples. The empirical coefficient method is one of the most commonly employed approach in calibration models. Incorporating appropriate matrix elements into the calibration model can significantly enhance the linear correlation between target elements and measured intensities, thereby improving the accuracy of results for unknown samples. However, an excessive number of matrix elements or unsuitable combinations in the calibration model may lead to "overfitting", where the model exhibits excellent fitting quality during calibration but yields analytical errors significantly higher than the fitting results when applied to real samples, failing to meet quality control (QC) requirements. This study proposed the use of stepwise regression analysis and single-element rotation optimization to efficiently screen matrix element combinations that satisfy QC criteria. After optimizing the matrix elements in the calibration model, the correlation coefficients of fitting indicators showed notable improvement. Experimental data from soil and sediment reference materials across 6 WD-XRF laboratories were used to validate the computational process. Results indicated that the screening outcomes of matrix elements depended on the reference materials included in the calibration model. Different combinations of reference materials might correspond to distinct screening results. For different target elements, 24-31 soil and sediment reference materials were employed as validation samples to evaluate the accuracy of the optimized calibration model. The qualification rates generally met QC requirements. Key considerations for practical application of the method were also discussed.

Yttrium(Y) and neodymium(Nd) are two important alloying elements in wrought magnesium alloy ingot.Therefore,the accurate determination of Y and Nd contents in wrought magnesium alloy ingot is of great significance for the product performance development.In this study,the samples were dissolved with 25 mL of hydrochloric acid(1+1) at room temperature for 5 min.Y 377.433 nm and Nd 401.225 nm were selected as the analytical lines for Y and Nd.The calibration curve was prepared by matrix matching method to eliminate the influence caused by matrix effect.A method for the determination of Y and Nd in wrought magnesium alloy flat ingot by inductively coupled plasma atomic emission spectrometry(ICP-AES) was established.The results showed that the linear correlation coefficients of calibration curves of Y and Nd were both 0.999 9. The limits of detection of Y and Nd were 0.000 84% and 0.000 73%,and the limits of quantification were 0.002 8% and 0.002 4%,respectively.The proposed method was applied for the determination of Y and Nd in magnesium alloy CRMs,the measurement results were consistent with the standard values.The contents of Y and Nd in three wrought magnesium alloy flat ingot samples were determined according to the experimental method,and the precision investigation and spiked recovery experiment were carried out.The relative standard deviations(RSD, n=6) of determination results were between 0.30% and 1.3%.The recoveries were between 94% and 101%.