The presence of oxygen and nitrogen impurities will seriously affect the performance of high purity copper. In this study, the sample surface was treated with lathe finishing followed by acid corrosion. Under the condition without flux, a method for the determination of trace oxygen and nitrogen in high purity copper by inert gas fusion-infrared absorption/thermal conductivity was established. The analytical power was 4 500 W. The effect of three surface treatment methods, including acid corrosion, lathe finishing, and lathe finishing followed by acid corrosion, on the determination of oxygen and nitrogen was investigated. The results showed that the influence of three surface treatment methods on the determination of nitrogen could be ignored. However, for the determination of oxygen, the determination results of lathe finishing followed by acid corrosion were much lower than those obtained by other two methods, indicating that the method of lathe finishing followed by acid corrosion could effectively remove the oxygen on sample surface. The certified reference materials of copper with low mass fraction as possible were selected to calibrate the analyzer for the determination of oxygen and nitrogen. The limits of quantification were 0.17 μg/g and 0.31μg/g for oxygen and nitrogen, respectively. The contents of oxygen and nitrogen in high purity copper sample were determined for seven times according to the experimental method. The results showed that the standard deviation (SD, n=7) of oxygen measurement values was 0.13-0.19 μg/g, and the SD (n=7) of nitrogen measurement values was 0.062-0.070 μg/g. The content of oxygen was also determined by glow discharge mass spectrometry (GD-MS) for method comparison. The measurement results of two methods were basically consistent. The high purity copper sample was selected and determined according to the experimental method. In addition, the certified reference material of copper was added for the spiked recovery test. The results showed that the recoveries of oxygen and nitrogen were between 80% and 120%.

When glow-discharge mass spectrometry (GDMS) is used to determine trace cadmium in nickel-based superalloy,it is interfered by ¹¹⁴Sn⁺ and MoO⁺ polyatomic ions. After pre-correction with standard relative sensitivity factor(RSF_Std), the mass spectral interferences of multi-atomic ions including ¹¹⁴Sn⁺ and MoO⁺ were corrected by interference correction equation. Thus, a method for determination of trace cadmium in nickel-based superalloy was realized by GDMS at high-resolution mode with ¹¹⁴Cd as analytical isotope. The instrument parameters were optimized as follows:the discharge current was 48 mA; the flow rate of discharge gas was 450 mL/min; the pre-sputtering time was 20 min. The certified reference materials of nickel-based wrought superalloy with Cd certified value less than 0.1 μg/g and Mo mass fraction of 3% were used as blank samples and determined for 11 times consecutively. The limit of election and limit of quantifiation, which were calculated according to three-fold and ten-fold of standard deviation of blank sample, were 0.081 μg/g and 0.27 μg/g, respectively. The content of cadmium in certified reference material or reference material of nickel-based superalloy were determined according to the proposed method, and the results were in good agreement with the certified value/standard value. The relative standard deviations(RSD,n=6) were less than 12%. The contents of cadmium in 3 nickel-based superalloy samples were determined according to the proposed method as well as inductively coupled plasma tandem mass spectrometry (ICP-MS/MS),respectively. The results showed that the results of the above two methods were basically consistent.

The high-throughput intelligent integrated characterization techniques,which were developed by researchers home and abroad based on the combination of high-throughput characterization techniques with intelligent integration concepts,were reviewed in this article.These new methods could help researchers accelerate the screening and experimentation by quickly exploring data and optimizing research conditions.The researches of high-throughput intelligent integrated characterization techniques included the modular chemical autonomous experimentation platforms,autonomous drug synthesis laboratories,and autonomous thin-film preparation and characterization platforms.These studies integrated intelligent robots with discrete combination modules,high-throughput preparation systems,and high-throughput physical and chemical performance testing systems to conduct autonomous experiments on material preparation and characterization.An automated,integrated,and intelligent physical experimental platform was constructed.And on this basis,an automated process of screening-preparation-collection-transmission-storage-analysis-feedback was established.An integrated positioning system and statistical mapping database were independently developed to provide new ideas for high-throughput characterization of materials and data support for material research and development.

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.

The addition of a high content niobium (Nb) in IN718 alloy leads to the precipitation of a large number of niobium-containing phases. The morphology, area fraction, quantity and shape of these niobium-containing phases are main factors affecting the properties of IN718 alloy. Therefore, the quantitative characterization of niobium-containing phases is of great significance for the study of the structure-activity relationship of the alloy. In this paper, the images of niobium-containing phases in the large field of view of IN718 alloy were efficiently acquired using high-throughput field emission scanning electron microscope based on its characteristics such as high imaging flux, fast automatic scanning speed and strong data processing ability. The image segmentation, recognition and statistical analysis module of niobium-containing phases were established by MIPAR image processing software, realizing the high efficiency extraction and quantitative statistical distribution characterization of niobium-containing phases in large size range of alloys. 1 225 backscattered electron (BSE) images were collected for each sample. These images were rapidly processed in batch using the established image processing module of niobium-containing phases. The information such as morphology and area fraction of niobium-containing phases in different regions of the cross section of IN718 alloy forged bar was obtained. It was found that the niobium phases in the core mostly had the shape of needles and long strips, and the area fraction was relatively high. However, there were more short-rod and round granular precipitated phases at the edge of the forgings. These data would provide guidance for the improvement of forging process and performance.

Q690D steel has excellent properties in strength and toughness. The inclusion in the steel is an important factor affecting the strength and toughness. The modification of inclusions is an important measure to improve the product performance. In order to investigate the modification effect of magnesium on inclusions in Q690D steel for construction machinery, the distribution pattern and size of inclusions in the steel before and after magnesium treatment were compared and analyzed using metallurgical microscopy, scanning electron microscopy, inclusion three-dimensional etcher and FactSage thermodynamic software. The results showed that the inclusions in Q690D steel after calcium treatment were mainly composed of CaO-Al₂O₃, and some of them were wrapped by CaS. The inclusions in magnesium treated steel were mainly composed of MgO·Al₂O₃ or MgO, and some of them were wrapped by MgS. Magnesium could make Al₂O₃ finer and more uniformly distributed, and the average equivalent diameter of inclusions was reduced. The number density and area fraction of inclusions in the magnesium treated rolling stock were 65 mm² and 0.031%, respectively, which were lower than those after treatment by calcium, i.e., 96 mm² and 0.050%, respectively. Magnesium treatment showed better effect to purity the molten steel and improve the size and distribution of inclusions.

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.

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 contents of Se,Ce,Zr,Ta and Te in nickel-based alloy will affect its processability, thermoplasticity, fatigue performance and creeping property. Therefore, their determination is of great significance. The sample was dissolved with hydrochloric acid, hydrogen peroxide and hydrofluoric acid. ⁷⁸Se, ¹⁴⁰Ce, ⁹⁰Zr, ¹⁸¹Ta and ¹²⁵Te were selected as test isotopes. The calibration curve was prepared by standard addition method to overcome the matrix effect. ¹⁰³Rh was used to correct ⁷⁸Se and ⁹⁰Zr, while ¹¹⁵In was used to correct ¹⁴⁰Ce, ¹⁸¹Ta and ¹²⁵Te. Consequently, a method for simultaneous determination of trace Se, Ce, Zr, Ta and Te (mass fraction below 0.005%) in nickel-based alloy N06625 was established by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the correlation coefficients of calibration curves of elements were all higher than 0.999 0. The limits of detection and limits of quantification were 0.004 5-0.38 μg/g and 0.015-1.28 μg/g, respectively. The samples of nickel-based alloy N06625 were determined according to the proposed method. The relative standard deviations (RSD, n=11) of determination results of 5 elements were between 0.87% and 9.9%, and the recoveries were between 92% and 107%. The proposed method was applied for determination of trace Se, Ce, Zr, Ta and Te in sample of nickel-based alloy N06625. The results of Se and Te were basically consistent with those obtained by hydride generation atomic fluorescence spectrometry(HG-AFS), and the results of Ce and Zr were basically consistent with those obtained by inductively coupled plasma atomic emission spectrometry(ICP-AES).

A method for analysing and characterizing the three-dimensional morphology and three-dimensional structural characteristic parameters of inclusions in steel was developed based on X-ray microscopy. Three different types of steels were selected to analyse the three-dimensional structural characteristic parameters and three-dimensional spatial distribution of inclusions, including the volume fraction, equivalent diameter, shape factor, diameter and volume distribution, sphericity and orientation. The results showed that the X-ray microscope could accurately characterize the inclusions with size of 1-500 μm in steel. It could also distinguish the high-density phase, non-metallic inclusions and micro-porosity based on the difference of contrast or grey. When the deformation of stainless steel reached 50%, the three-dimensional morphology of plastic inclusions evolved from spherical to flat, and the shape factor decreased from 0.67 to 0.57, and the spatial orientation angle (Phi) increased from 63.48° to 77.40°. For the steel treated with Te, the element of Te was wrapped outside the MnS to form a composite inclusion, which improved the corrosion resistance of the steel. According to the three-dimensional structural characteristic parameters of MnS inclusions, the three-dimensional grain boundaries of sulphur-containing steel were divided, and the relationship between the precipitation process of grain boundary inclusions and solidification selective crystallization was explained. A new method for characterizing the three-dimensional morphology and structural of inclusions in steels was established instead of synchrotron radiation, which was to promote the research of controlling the inclusions modification evolution of characterizing inclusions using X-ray microscopy. The proposed method provided more accurate and reliable analytical and testing approaches for the control of inclusions.

The accurate determination of calcium fluoride content in low-grade fluorite tailings is of great significance for the evaluation and improvement of comprehensive recycling process.The semi-quantitative component analysis of low-grade fluorite tailings sample was first conducted by wavelength dispersion X-ray fluorescence spectrophotometer (WDXRF) and X-ray diffractometer (XRD). It was found that fluorine mainly existed in the form of calcium fluoride, and the sample mainly contained silicon, aluminum, iron, calcium, magnesium, potassium, sodium, sulfur and manganese. 4.0 g of potassium hydroxide and 0.35 g of potassium nitrate were used as flux. The sample was melted at 650 ℃ for 8 min and then leached with hot water. IC-Na pretreatment column was used to separate alkaline earth and transition metal cations such as aluminum, iron, calcium, magnesium and manganese. Thus, a method for determination of calcium fluoride in low-grade fluorite tailings was established by alkali fusion-ion chromatography. The results showed that the mass concentrations of cations such as aluminum, iron, calcium, magnesium and manganese in test solution were all lower than 0.1 μg/mL after separation with IC-Na pretreatment column. Therefore, the interference of these elements with the determination could be ignored. The calibration curve was drawn with the mass concentration of fluorine ion as x-axis and its corresponding peak area response as y-axis. The results indicated that its correlation coefficient was 0.999 6 with calcium fluoride in range of 1-30 μg/mL. Two fluorite tailings samples and one reference material of fluorite ore were determined according to the proposed method. Meanwhile, different amounts of high-grade fluorite ore certified reference material were added for recovery tests. The recoveries were between 96% and 104%. The proposed method was applied for determination of calcium fluoride in low-grade fluorite tailings samples and fluorite ore reference materials. The relative standard deviations (RSD, n=7) were between 0.54% and 1.5%. The results were consistent with those obtained by ion selective electrode method or the standard values. The proposed method was applicable for determination of calcium fluoride in low-grade fluorite tailings samples with mass fraction in range of 5%-60%.

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.

Selenium (Se) is an amphoteric non-metallic element. As one of the essential trace elements for human body, the insufficient or excessive intake of Se will be harmful to human health. As the material basis for human survival, soil is the most fundamental source for people to obtain Se from the outside world. Therefore, it is of great practical significance to establish a highly sensitive and accurate method for the detection of Se in soil and stream sediments. Due to the characteristics of simple analysis operation, high sensitivity, fast analysis speed and low operating cost, the hydride generation-atomic fluorescence spectrometry (HG-AFS) is widely used for the determination of Se. However, the pretreatment method, light source and coexisting elements may interfere with the determination of Se, affecting the test results. In this paper, the sources and causes of the interference of Se in soil and stream sediments by atomic fluorescence spectrometry were focused on. The research and application progress of Se interference elimination were summarized and discussed. Moreover, the future development direction of hydride generation-atomic fluorescence spectrometry in the determination of Se in soil and stream sediments were prospected.

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.

Calcium, magnesium, iron, silicon, aluminum, manganese, beryllium and phosphorus in spodumene are determined by the series of methods 3, 4, 5, 6, 7, 8 and 10 in industrial standard YS/T 509-2008 of Methods for chemical analysis of spodumene and lepidolite concentrates. The results are accurate, but there are many kinds of reagents used and the process is complicated. After the spodumene sample was treated by alkali fusion with sodium hydroxide at 630 ℃ for 15 min, it was acidified and leached with hydrochloric acid (1+3). By selecting the optimal analytical lines of elements, the contents of calcium, magnesium, iron, silicon, aluminum, manganese, beryllium and phosphorus in spodumene were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The calibration curve was drawn by matrix matching method to eliminate the influence of matrix effect. The linear correlation coefficients of calibration curves for elements were all higher than 0.999 7. The limits of quantification of elements were between 0.061 5 μg/g and 123.9 μg/g. The contents of calcium, magnesium, iron, silicon, aluminum, manganese, beryllium and phosphorus in two spodumene samples were determined according to the proposed method, and the relative standard deviations (RSD, n=7 or n=8) of determination results were all less than 2.5%. The contents of calcium, magnesium, iron, silicon, aluminum, manganese, beryllium and phosphorus in certified reference material of spodumene were determined according to the proposed method. The relative errors (RE) of determination results were between -5.00% and 7.31%.

The accurate determination of iron in copper concentrate will affect the pricing and transaction of copper concentrate, the regulation of slag pattern in melting process, and the heat effect of smelting furnace. In this study, the sample was decomposed by hydrochloric acid, nitric acid, bromine, and sulfuric acid. Matrix copper in sample was converted into copper (Ⅱ), which was used as the reduction end-point indicator of iron (Ⅲ) as well as the catalyst of iron (Ⅲ) reduction. Iron (Ⅲ) was reduced to iron (Ⅱ) with potassium borohydride in sulfuric acid medium. Then the method for determination of iron content in copper concentrate by potassium dichromate titration was established using sodium diphenylamine sulfonate as the indicator. In experiments, 0.20 g of sample was dissolved with 0.1 g of ammonium bifluoride, 10 mL of hydrochloric acid, 5 mL of nitric acid, 0.5 mL of bromine, and 10 mL of sulfuric acid (1+1). After sulfuric acid smoke until the volume of solution was 1 mL, the acidity of potassium borohydride reduction process could be ensured. Copper (Ⅱ) in test solution had a catalytic effect on the reduction of iron (Ⅲ) by potassium borohydride, and it had no interference with the determination of iron. When the concentration of potassium borohydride was 20 g/L, iron (Ⅲ) could be effectively reduced to iron (Ⅱ), and meanwhile, it did not affect the determination of iron. The titration endpoint was clear when the amount of sulfuric acid and phosphoric acid mixture was 15 mL. The interference tests indicated that the interference of coexisting elements in sample with the determination of iron could be ignored. The copper concentrate reference materials and actual samples with different contents of copper were selected, and the content of iron was determined according to the experimental method. The relative standard deviations (RSD, n=7) of the determination results were between 0.20% and 0.55%. The national standard method GB/T 3884.15-2014 was used for method comparison,the t-test was conducted on the measurement results of the two methods, and the results showed that there was no significant difference between the two methods.The proposed method could be used for the rapid analysis and determination of iron content in copper concentrate in large quantities in smelting enterprises.

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%.

Platinum and palladium are precious metal elements with high price. The contents of platinum and palladium in crude selenium is an important indicator for trade settlement, so it is of great significance to accurately determine the contents of platinum and palladium in crude selenium. In this study, a method for the determination of platinum and palladium in crude selenium by inductively coupled plasma atomic emission spectrometry (ICP-AES) after selenium volatilization with perchloric acid was established. The samples were dissolved in aqua regia. The interference of selenium matrix was eliminated by perchloric acid smoke to volatilize the selenium. Pt 265.945 nm and Pd 360.955 nm were used as the analytical lines for the determination in the medium of 10% aqua regia. The results showed that 1.0 g of sample could be completely dissolved by adding 15 mL of aqua regia. Most of the selenium matrix could be removed by adding 10 mL of perchloric acid for volatilization at high temperature. A small amount of residual selenium matrix and other coexisting elements had no interference with the measurement. The weighing method was adopted during whole test to reduce the personal error and measurement instrument error caused by volume calculation method. The content of platinum and palladium in range of 0.02-15.0 μg/g was linear to the corresponding intensity. The correlation coefficients were 0.999 93 and 0.999 98, respectively. The limits of detection for platinum and palladium were 0.000 094% and 0.000 11%, and the limits of quantification were 0.000 31% and 0.000 33%, respectively. The experimental method was used to determine platinum and palladium in crude selenium, the relative standard deviations (RSD, n=7) were less than 5%. The measured results were consistent with those obtained by oxidizing roasting-lead fire assay-ICP-AES. The precision and trueness were superior to the conventional volume calculation method. The recoveries of platinum and palladium in crude selenium sample were 98%-105% and 99%-104%, respectively.

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 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.

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.

A special zinc sulfate solution has appeared in the raw material procurement market for wet zinc smelting. Such zinc sulfate solution contains high contents of manganese and aluminum, which will cause interference with the determination of zinc content, seriously affecting the determination results. In this study, the zinc sulfate solution containing high content of manganese and aluminum were treated for precipitation separation of manganese in solution. Then, excessive EDTA was added to complex zinc and aluminum in acetate-sodium acetate buffer solution. The excess EDTA was titrated with zinc standard solution to obtain the total amount of EDTA that was used to complex zinc and aluminum. The Al-EDTA complex was then decomposed with ammonium fluoride, and the released EDTA was titrated with zinc standard solution. The content of zinc in zinc sulfate solution could be indirectly measured by subtracting the amount of Al-EDTA complex released EDTA from the total amount of EDTA. The contents of zinc in three high-manganese and high-aluminum zinc sulfate solution samples were determined according to the experimental method. The relative standard deviations (RSD,n=11) of measurement results were between 0.27% and 0.29%, which was less than the 0.30% required in general titration operations. The recoveries were between 95% and 101%.

The content of lithium oxide in lithium ore is the key factor affecting the price of lithium ore. The atmospheric decomposition method is commonly adopted for the determination of lithium oxide in lithium ore, but it has some problems such as complicated operation and large consumption of acid. The sample was treated with 1.5 mL of sulfuric acid and 2.0 mL of hydrofluoric acid by super microwave digestion at 280 ℃. After digestion, the solution was continuously heated until sulfuric acid fuming to remove silicon and excessive hydrofluoric acid. The salts were redissolved with 1.0 mL of sulfuric acid and 25 mL of water by heating, and lithium in the test solution was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) with Li 610.365 nm as analytical line and emission power as 0.95 kW. Consequently, a method for determination of lithium oxide in lithium ore was established by ICP-AES after super microwave digestion. The mass concentration of lithium in range of 0.50-50.0 mg/L showed good linear relationship with its corresponding emission intensity. The correlation coefficient (r) was 0.999 7. The limit of detection of this method was 1.5 mg/kg for lithium oxide. The contents of lithium oxide in three lithium ore samples were determined according to the proposed method, and the relative standard deviations (RSD, n=8) of determination results were between 0.92% and 2.0%. The proposed method was applied for determination of two certified refence materials of lithium ore, and the results were consistent with the certified values. Two assay laboratories were selected for determination of the contents of lithium oxide in lithium ore samples according to the proposed method, and the results were consistent. Compared with the current standard methods of GB/T 509.1-2008 and GB/T 17413.1-2010, this method could save 80% of hydrofluoric acid dosage during digestion, and it is suitable for rapid inspection and clearance of imported and exported lithium ore.

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 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.

The solid waste resource regeneration is crucial for achieving the goals of "carbon peaking and carbon neutrality" and "zero-waste city construction", and it is also a key link in comprehensively promoting the achievement of a beautiful China. Zinc oxide concentrate (ZnO-C) is a mixture mainly containing ZnO obtained by pyrometallurgical volatilization and enrichment of Zn-containing solid waste. The impurities include metallic elements (such as iron, aluminum and calcium) and nonmetallic elements (such as fluorine, chlorine, silicon and sulfur). ZnO-C is powder-like with color of grey and black, and it is a typical waste resource utilization product. The quality of ZnO enrichment by pyrometallurgical method is different due to the difference of raw material components and technology level. In this study, the typical regeneration ZnO-C enriched material was focused on. The raw material components, enrichment process and technical parameters of pyrometallurgical enrichment were investigated. The production process and main physicochemical characteristics of ZnO-C were systematically discussed. Given that the composition of ZnO-C was crucial for subsequent processing and utilization, the content of ZnO phase as well as the composition and content of other phases in typical ZnO-C were also paid attention to. The accurately analysis and identification of ZnO-C was the key to port supervision of imported renewable resources and a prerequisite for achieving resource utilization.

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.

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.

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.

Effect of heat treatment temperature and time on phase variation characteristic of decomposition product of crystalline aluminum chloride was investigated. The composition and microtopography of crystalline aluminum chloride were analyzed and discussed by inductively coupled plasma atomic emission spectrometer (ICP-AES) and metallographic microscope. The results showed that the purity of crystalline aluminum chloride was relatively high. It contained trace impurity elements such as sodium and calcium, and it belonged to orthorhombic structure. While, aluminum oxide showed irregular elliptic with particle size of 100-210 μm. The phase change characteristics of decomposition product were investigated with thermal gravimetric analyzer and X-ray diffractometer (XRD). The results showed that the crystalline aluminum chloride lost small amount of free water under heat treatment at 80-100 ℃. The decomposition rate after 120 min was 6.95%, and the phase was still crystalline aluminum chloride. The decomposition rate was 35.84% after heat treatment at 150 ℃ for 120 min. The decomposition rate was 87.31% after heat treatment at 200 ℃ for 120 min. The decomposition velocity at 600-1 200 ℃ was very fast, and the sample could be completely decomposed within 5 min. The decomposition rate of crystalline aluminum chloride was in direct proportion to heat treatment temperature and time, and heat temperature was the dominant factor. When the heat treatment temperature was 200-700 ℃, the decomposition product phase was ρ-type or amorphous aluminum oxide. When the heat treatment temperature was 800-1 000 ℃, the decomposition product phase was mainly in γ-type, δ-type and or η-type aluminum oxide. Wherein, a small amount of α-type aluminum oxide was observed in decomposition product at 1 000 ℃. When the heat treatment temperature reached 1 200 ℃, all phases were converted into α-type aluminum oxide with most stable energy. This study provided data basis for the theoretical research and pilot equipment selection in heat treatment of crystalline aluminum chloride in the laboratory. It also provided data support for the process parameter optimization in heat treatment of crystalline aluminum chloride.

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.

Accurate prediction of bolt fatigue life is very important to guarantee the engineering safety and draw up the maintenance plan. Paris formula is a model which is widely accepted in fatigue analysis. The importance of Paris formula in fatigue life calculation was discussed by analyzing the fatigue fracture of 10.9-grade bolts for pressure vessel. Moreover, the accuracy of Paris formula in failure prediction was also verified. The chemical element analysis, metallographic structure analysis and electron microscopy observation were conducted. The fatigue bands were measured and the data fitting of fatigue band width was performed for the inversion of the fatigue life of two bolt fracture. The results indicated that the crack propagation life of #1 bolt and 2# bolt were 17 251 cycles and 19 549 cycles, respectively. The finite element model verification results showed that the crack propagation life of #1 bolt and 2# bolt were 16 228 cycles and 18 525 cycles, respectively, which were in good agreement with the proposed data. The relative error of fatigue life between the analogue simulation and calculation result were not more than 6%. It was indicated that Paris formula could be used for the accurate prediction of bolt failure under certain conditions, and it provided reliable reference for the improvement of structural part safety.

The accurate determination of silicon content in chromium carbide is of great significance for the quality control of products. The sample was fused with sodium peroxide. After leaching with hot water and acidification, chromium was removed by volatilization with hydrochloric acid. Under certain acidity conditions, silicon could react with ammonium molybdate to form silicon molybdenum yellow. The mixture of oxalic acid and sulfuric acid was added to eliminate the interference of phosphorus and iron, and ascorbic acid was added to reduce silicon molybdenum yellow to silicon molybdenum blue for spectrophotometric determination at 810 nm. Thus, a method for determination of silicon in chromium carbide was established by silicon molybdenum blue spectrophotometry with alkali fusion. The results showed that the mass concentration of silicon in range of 0.05-1.20 μg/mL showed good linear relationship with its corresponding absorbance with correlation coefficient of 0.999 9. The apparent molar absorptivity was ε=22.41×10³ L·mol^-1·cm^-1. The limit of detection and limit of quantification for this method were 0.001 7% and 0.005 2%, respectively. The interference tests of coexisting ions showed that the residual chromium in test solution as well as phosphorus and iron in sample had no interference with the determination of silicon. The contents of silicon in three chromium carbide samples were determined according to the proposed method, and the relative standard deviations (RSD, n=9) were between 0.51% and 5.8%. Two chromium carbide samples were conducted for standard addition recovery tests, and the recoveries were between 97% and 102%.

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.

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).

The determination uncertainty could intuitively reflect the quality control level of determination process. With the issue and implementation of standards such as GB/T 22553, Top-down method has attracted more and more attention. The determination uncertainty of niobium content in IN718 nickel-based superalloy was evaluated and compared based on Top-down method and GUM method. It was found that the uncertainty evaluated by reproducibility standard deviation (s_R) in Top-down method was much higher than that in GUM method. The related references about the uncertainty evaluation of metal materials in recent years were analyzed. The simplified Top-down method was used. The ratio (U(R_w)/U(w)) of the uncertainty evaluated by intermediate precision to the uncertainty evaluated by GUM method was treated by robust statistical method. It was found that the robust mean value was 1.20, and the robust standard deviation was 0.48, indicating that the evaluation results of the two above methods were in good agreement. Compared to GUM method, the simplified Top-down method did not require to identify the components of weighing, certified reference material and repeatability. Moreover, the complicated calculation and combination were not necessary. The evaluation process was simple and easily conducted. The proposed method could help the laboratories evaluate the uncertainty conveniently and rapidly, which could promote the improvement of laboratory quality control level.

As an advanced means of micro and nano processing, the focused ion beam technology has a wide application prospect in the steel industry. In this paper, 82A cord steel billets and 55SiCr spring steel billets were selected as the test materials. A series of slicing and three-dimensional (3D) reconstruction of the composite inclusions were performed using the focused ion beam(FIB). It was found that there were some factors having adverse effects on the results in the 3D reconstruction process, such as method calibration and phase contrast differences. The results showed that the problems of distortion of reconstructed morphology and large deviation of size determination could be solved by introducing the offset calculation formula. Moreover, the reconstruction possibility of phases with insignificant differences in phase contrasts was realized by introducing energy dispersive spectroscopy mapping analysis in the series slicing process, which effectively solved the difficulties encountered in the current 3D reconstruction process and made the reconstruction results better support the project of research and development.

The accurate determination of iron content in lanthanum cerium carbonate is of great significance for quality control and subsequent application of its products. The content of iron in lanthanum cerium carbonate is commonly measured by spectrophotometry. However, when the iron content was low (below 0.3%), the color change was not obvious in the determination. Moreover, the coloring process is very easily affected by other impurity ions. In this study, the sample was dissolved with hydrochloric acid, and its acidity in solution was controlled at 2%. Fe 259.939 nm was selected as the analytical line for iron. The calibration curve was prepared by standard addition method to eliminate the influence of factors such as lanthanum cerium carbonate matrix on the determination results. The content of iron in lanthanum cerium carbonate was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The linear correlation coefficient of calibration curve was 0.999 9. The limit of detection of the method was 0.001%. The content of iron in lanthanum cerium carbonate was determined according to the experimental method. The relative standard deviations (RSD, n=11) of the measurement results were between 1.3% and 3.3%, and the spiked recoveries were between 98% and 103%.

With the increasing application of magnesium and magnesium alloy, there are more and more requirements for the determination of harmful element arsenic. The sample was dissolved in nitric acid in batches by heating at low temperature. Then the acidity was adjusted with hydrochloric acid followed by adding 10 mL of thiourea-ascorbic acid solution in order to reduce As(Ⅴ) to As(Ⅲ). Thus, a method for determination of trace arsenic in magnesium and magnesium alloy was established by hydride generation atomic fluorescence spectrometry (HG-AFS). Since there are many product types and groups of magnesium and magnesium alloy, such as magnesium-aluminum series, magnesium-zinc series, magnesium-manganese series, magnesium-lithium series and magnesium-rare earth series, the effects of magnesium matrix as well as the maximum content of aluminum, zinc, manganese, copper, nickel, lithium, lanthanum, cerium, praseodymium, neodymium, gadolinium, yttrium, erbium and dysprosium in magnesium alloy on the determination of arsenic were investigated. The results showed that the interference of magnesium matrix and major alloying elements in magnesium alloy with the determination of arsenic could be ignored. It was found that the mass concentration of arsenic in range of 1.00-10.00 μg/L had linear relationship with its corresponding fluorescence intensity. The correlation coefficient of calibration curve was 0.999 7. The limit of detection of method was 0.001 4 μg/g, and the limit of quantification was 0.004 2 μg/g. Three magnesium alloy samples were determined according to the proposed method, and arsenic standard solution was added for recovery test. The relative standard deviations (RSD, n=6) of determination results were between 2.4% and 5.3%, and the recoveries were between 98% and 106%. The method comparison tests indicated that the determination results of the proposed method were basically consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS).

Manganese could enhance the toughness of ferroboron. The accurate determination of manganese is helpful for the production of high-quality ferroboron alloy materials. The sample was dissolved in aqua regia at low temperature and digested by perchloric acid fuming. Manganese was oxidized to septivalent with sodium periodate in sulfuric acid-phosphoric acid medium and then determined at 530 nm by spectrophotometry. Thus, a method for determination of manganese in ferroboron was established by periodate sodium oxidization spectrophotometry. The samples were treated by three methods, i.e., perchloric acid fuming in presence of sulfuric acid and phosphoric acid, perchloric acid fuming followed by adding sulfuric acid-phosphoric acid, and slag dissolution with acid. The results showed that the determination results of manganese in ferroboron samples were basically consistent by the three methods above. The determination results of manganese in certified reference materials/reference material of ferroboron were consistent with the certified values/standard value. Wherein, the operation of perchloric acid fuming followed by adding sulfuric acid-phosphoric acid was the most simple. The determination range of method was 0.050%-1.00% (mass fraction, the same below). The correlation coefficient of calibration curve was 0.999 99. The apparent molar absorptivity was 2.3×10³ L·mol^-1·cm^-1. The limits of detection and limits of quantification for this method were 0.004% and 0.012%, respectively. The contents of manganese in certified reference material and actual samples of ferroboron were determined according to the proposed methods. The relative standard deviations (RSD, n=11) of determination results were between 0.25% and 0.46%. The contents of manganese in three certified reference materials/reference material and two actual samples of ferroboron were determined according to the proposed methods. The determination results of certified reference materials/reference material were consistent with the certified values/standard value, and the determination results of actual samples were consistent with those obtained by slag dissolution with acid-inductively coupled plasma atomic emission spectrometry (ICP-AES).