Top access

  • Published in last 1 year
  • In last 2 years
  • In last 3 years
  • All

Please wait a minute...
  • Select all
    |
  • OUYANG Yu, HU Jingyu, SHAO Qiuwen, HOU Yanxia, YANG Guowu
    Metallurgical Analysis. 2024, 44(12): 1-6. https://doi.org/10.13228/j.boyuan.issn1000-7571.012515
    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(RSFStd), 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.
  • SONG Yan, WANG Peng, YANG Zhigang, LI Dongling, BAO Lei, WANG Haizhou
    Metallurgical Analysis. 2024, 44(11): 1-8. https://doi.org/10.13228/j.boyuan.issn1000-7571.012492
    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.
  • FAN Xin, ZHAO Yanbing
    Metallurgical Analysis. 2024, 44(12): 7-13. https://doi.org/10.13228/j.boyuan.issn1000-7571.012537
    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).
  • LI Jingyan, CHU Xiaoli, CHEN Pu, XU Yupeng, LIU Dan
    Metallurgical Analysis. 2024, 44(10): 1-9. https://doi.org/10.13228/j.boyuan.issn1000-7571.012513
    In recent years,the integration of modern spectroscopic analysis technologies with development characteristics of the times (such as artificial intelligence,big data,cloud computing and the internet of things) is closer and closer,and it has been widely used in various fields including agriculture,food,petrochemicals,petrochemical engineering,metallurgy and geology.Some large-scale application achievements have been obtained in several fields,which makes a contribution to the development of technology and economy.This paper mainly introduces the constitution and characteristics of modern spectroscopic analysis technologies integrated with chemometrics,and summarizes the chemometric methodologies and advancements employed for quantitative and qualitative analysis in spectroscopy.Based on some representative instances,the application status of modern spectroscopic analysis technologies in various fields were introduced according to the application scenarios,for example,the laboratory high-throughput analysis scenarios such as rapid crude oil evaluation,grain sorting and port iron ore classification;on-site rapid analysis scenarios such as soil detection,mineral exploration,fruit picking assessment,and forensic identification;the industrial on-line analysis scenarios such as gasoline blending,smelting process material analysis,on-line coal quality analysis,and waste plastic classification.In the future,grounded in the miniaturization of spectrometers,in-depth exploration of new spectroscopic theories,and the profound amalgamation of deep learning algorithms with spectroscopic technology,the rapid developments in precision agriculture,smart factories,precision medicine,and intelligent environmental protection will offer robust impetus for the progressive evolution of modern spectroscopic analysis technologies,thus heralding further innovations and advancements.
  • YUAN Qi, ZUO Hongyi, ZHU Zanfang
    Metallurgical Analysis. 2024, 44(11): 53-59. https://doi.org/10.13228/j.boyuan.issn1000-7571.012648
    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.
  • LIU Qiang, LI Xiang, CHENG Huijing, GAO Ming, LIU Wei, YANG Shufeng
    Metallurgical Analysis. 2024, 44(11): 20-27. https://doi.org/10.13228/j.boyuan.issn1000-7571.012514
    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.
  • XUN Kanyu, ZHONG Yixin, YAO Huimin, WAN Qian, LIU Jie, TAN Jing
    Metallurgical Analysis. 2024, 44(11): 45-52. https://doi.org/10.13228/j.boyuan.issn1000-7571.012576
    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.
  • CAO Haotian, XU Kang, FU Jianxun, SHEN Ping
    Metallurgical Analysis. 2024, 44(11): 9-19. https://doi.org/10.13228/j.boyuan.issn1000-7571.012463
    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.
  • BAI Weihua, ZHOU Haishou, HAN Weiru, LIU Liyuan, WANG Changhua, LI Na
    Metallurgical Analysis. 2024, 44(11): 72-77. https://doi.org/10.13228/j.boyuan.issn1000-7571.012488
    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%.
  • YANG Yanhui, LIAO Shiying, CHEN Ge, ZHANG Jie, JIANG Xianfang, CHEN Yijun
    Metallurgical Analysis. 2024, 44(12): 33-39. https://doi.org/10.13228/j.boyuan.issn1000-7571.012570
    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%.
  • ZHANG Zhuojia, LIU Jie, ZHOU Jiaolian, XIE Lifang
    Metallurgical Analysis. 2024, 44(12): 14-20. https://doi.org/10.13228/j.boyuan.issn1000-7571.012516
    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%.
  • AN Xiaokang, ZHANG Min, KOU Xiaoxiao, LEI Lei, MA Yuhua
    Metallurgical Analysis. 2024, 44(11): 97-102. https://doi.org/10.13228/j.boyuan.issn1000-7571.012451
    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%.
  • CAI Weiting, ZHAO Changyu, WANG Anli, RONG Wenna, SONG Junpeng, LI Bei
    Metallurgical Analysis. 2024, 44(11): 84-88. https://doi.org/10.13228/j.boyuan.issn1000-7571.012499
    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%.
  • LIANG Yuefeng, YAN Zhuowen, TANG Manna, XUAN Jianwen, XIAO Dahui, HE Yingxian
    Metallurgical Analysis. 2024, 44(12): 27-32. https://doi.org/10.13228/j.boyuan.issn1000-7571.012555
    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.
  • FENG Junli, HE Hongping, XUE Ya, ZHANG Qingjian
    Metallurgical Analysis. 2024, 44(11): 34-44. https://doi.org/10.13228/j.boyuan.issn1000-7571.012640
    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.
  • LIU Fangmei
    Metallurgical Analysis. 2024, 44(11): 60-65. https://doi.org/10.13228/j.boyuan.issn1000-7571.012469
    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.
  • WU Yuanyuan, JIN Chuanwei, ZHANG Jiming
    Metallurgical Analysis. 2024, 44(11): 28-33. https://doi.org/10.13228/j.boyuan.issn1000-7571.012454
    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.
  • XUE Ning, SUN Gaihua
    Metallurgical Analysis. 2024, 44(12): 55-59. https://doi.org/10.13228/j.boyuan.issn1000-7571.012585
    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).
  • WANG Xuewei, CHEN Chunyong, FENG Liqiong, JIN Tingting, CHEN Na, FANG Wentao
    Metallurgical Analysis. 2024, 44(11): 89-96. https://doi.org/10.13228/j.boyuan.issn1000-7571.012509
    The content of CaF2 in cassiterite and lead zinc sulfide co/associated fluorite is in range of 1%-50% (mass fraction, the same below). However, the current industry standard method is applicable for fluorite samples with CaF2 content higher than 3%. There is an empirical correction coefficient of 0.30% in industry standard methods, so the accuracy of CaF2 determination results below 10% is not high. In this study, acetic acid (1+9) was used to separate and remove calcium containing impurities such as CaCO3 and CaSO4 that are easily soluble in acetic acid. Then the content of F- which was slightly soluble in the filtrate was determined by ion selective electrode method. The residue was extracted using AlCl3, and In was selected as the internal standard element. The content of Ca in the extraction solution was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results of two methods were converted into CaF2 and then added together to obtain the CaF2 content in fluorite. Therefore, a method for the determination of calcium fluoride in cassiterite and lead zinc sulfide co/associated fluorite by ion selective electrode combined with ICP-AES was established. The effects of AlCl3 solution mass concentration, AlCl3 solution extraction time, and the selection of Ca and its internal standard element spectral lines on the determination of Ca were investigated. The limit of detection of CaF2 in the method was 0.010%, and the limit of quantification was 0.040%. The contents of CaF2 in actual samples of cassiterite, lead zinc sulfide, and fluorite certified reference material were determined according to the experimental method. The relative deviations (RSD, n=6) of the measurement results were between 0.22% and 0.90%, and the relative errors (RE) were between 0.08% and 0.63%. The method solved the problem of empirical correction coefficient in the CaF2 determination process. The internal standard method was employed in ICP-AES to eliminate the impact of instrument drift caused by environmental temperature fluctuations and changes in electronic component performance on the analysis results. The measurement range of the proposed method was effectively improved, and it could be used for the determination of CaF2 in cassiterite and lead zinc sulfide co/associated fluorite.
  • WANG Xiangde, LIU Hanxiao, BAI Zhanming, GU Xusheng, YANG Xueru, LIU Kai
    Metallurgical Analysis. 2024, 44(12): 47-54. https://doi.org/10.13228/j.boyuan.issn1000-7571.012532
    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 (sR) 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(Rw)/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.
  • MENG Wei, LI Yahua, ZHOU Shengqiang
    Metallurgical Analysis. 2024, 44(12): 72-77. https://doi.org/10.13228/j.boyuan.issn1000-7571.012541
    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).
  • CHANG Gao, FENG Cheng, LI Liang, ZHANG Jingru, ZHANG Zuoyu
    Metallurgical Analysis. 2024, 44(11): 66-71. https://doi.org/10.13228/j.boyuan.issn1000-7571.012494
    The test of alkaline value can be used to evaluate the content of alkaline additives in engine oil, and it is one of important indicators for evaluating the performance of engine oil. In this study, the dissociation constants of 20 types of engine oils were introduced into the Henderson-Hasselbalch equation. By combining with the Nernst equation, the theoretical endpoint pH values of different engine oils were calculated. The statistical analysis was conducted using the robust statistical algorithm A in statistics, and it was found that the endpoint pH value applicable for all engine oils was -4.5. A method for determining the alkaline value of engine oil by pH potentiometric titration was established using the mixture of acetic acid and chlorobenzene as the solvent and using the mixture of perchloric acid and acetic acid as the titrant. The limit of detection of this method was 0.004 1 mg KOH/g. The standard substance of alkaline engine oil was diluted with base oil that contained no alkaline substances. After well mixing, the blank spiked samples with alkaline content of 2, 5, and 20 mg KOH/g were prepared and determined according to the experimental method. The relative standard deviations (RSD, n=6) of the measurement results were between 0.60% and 1.2%, and the recoveries of blank spiked samples were between 99% and 102%. Various engine oil Petroleum Product Alkalinity Determination Method (Perchlorate Potentiometric Titration Method) was used for method comparison. The results showed that the difference between the two methods was within the repeatability limit required by the industry standard SH/T 0251-1993. Four standard substances of engine oil with different alkaline levels were selected and determined according to the experimental method. The test results were within the range of standard deviation, and the RSDs (n=6) were between 0.37% and 0.81%. The proposed method was applied for the determination of five types of engine oil samples, and the RSDs (n=10) of measurement results were less than 1%.
  • MU Yinghua, HU Weizhu, WANG Yapeng
    Metallurgical Analysis. 2024, 44(11): 78-83. https://doi.org/10.13228/j.boyuan.issn1000-7571.012482
    Silicon carbide deoxidizer is a kind of high-performance complex deoxidizer. The determination of titanium content can trace the elemental introduction and loss in smelting process, thus more effectively improving the properties of steel. The composition of silicon carbide deoxidizer is complicated. In this study, the sample was treated by melting at high temperature. Sodium carbonate and sodium peroxide were used as mixed flux. The nickel crucible containing sample and mixed flux was heated in high-temperature furnace at 400 ℃. Then the temperature was increased to 900 ℃ and kept for 30 min to melt the sample. After complete fusion, the sample was leached with hot water and acidified with hydrochloric acid. After dilution to the mark, the solution was filtered. Ti 334.941 nm was selected as the analytical line for titanium. The calibration curve was plotted by matrix matching method. The content of titanium in filtrate was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Consequently, the determination of titanium in silicon carbide deoxidizer was established. The linear correlation coefficient of calibration curve for titanium was above 0.999 9. The limit of detection was 0.000 5% (mass fraction). The content of titanium in silicon carbide deoxidizer sample was determined according to the experimental method, and the relative standard deviation (RSD, n=7) of measurement results was 2.0%. The spiked recoveries were between 98% and 102%. The contents of titanium in seven silicon carbide deoxidizer samples were determined according to the experimental method and spectrophotometry in national standard GB/T 16555-2017. The results were consistent.
  • GUAN Yanchao, HAN Zhengpeng, XU Xiangyu, FU Jianxun
    Metallurgical Analysis. 2025, 45(2): 1-9. https://doi.org/10.13228/j.boyuan.issn1000-7571.012593
    630 stainless steel (hereinafter referred to as SUS630) stands out in cutting-edge industries due to its exceptional mechanical properties and corrosion resistance. The customers require very high standards on its purity. In this paper, the cleanliness of five SUS630 products from three processes (continuous casting, mold casting, and electroslag remelting) was investigated. The types, distribution, three-dimensional morphology, and microstructure of inclusions were compared using optical microscopy (OM), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and electron probe microanalysis (EPMA). The results showed that the domestic A sample produced by the electroslag process was the cleanest, with an inclusion density of 18 inclusions/mm2 and an area fraction of 0.009%. The domestic B sample from the continuous casting process had the highest inclusion density and contained large-sized sulfide inclusions. The Japanese sample produced by the same mold casting process exhibited a uniform distribution of inclusions, while the domestic C sample showed significant Nb(N,C) segregation, posing a risk of pitting corrosion. This study filled a gap in the research on inclusions in SUS630 and provided data support for the future development of high-grade SUS630.
  • XU Xinxia, LIU Jia, CUI Feipeng, LI Yaqiang, GUO Feifei, SHEN Xuejing
    Metallurgical Analysis. 2024, 44(10): 31-37. https://doi.org/10.13228/j.boyuan.issn1000-7571.012434
    In recent years,some intelligent sorting technologies for scrap metals based on algorithms and material composition have gradually emerged,including machine vision,X-ray fluorescence spectrometry(XRF),X-ray diffraction topography(XRT) and laser-induced breakdown spectroscopy(LIBS).The latest progress of these technologies in classification of scrap metals were reviewed.It indicated that the machine vision had achieved industrial application demonstration with a high level of automation,but further improvements were needed to address its sensitivity to the environmental conditions.The elemental identification capabilities of XRF/XRT were strong,but limited to specific metal types.Currently,the commercial instruments for sorting metals,plastics,and ores are quite mature in the market.LIBS technology,with its wide elemental detection range that theoretically covers the entire periodic table,suffers from low detection efficiency and is still under research and development.Each technology above has its advantages and disadvantages,requiring integration and innovation to optimize the sorting results.In the future,the combination use of multiple technologies should be explored to enhance sorting capabilities,customized to meet market demands,and independent research and development should be strengthened to enhance core competitiveness.Full-process automation will improve efficiency,and the integration of artificial intelligence(AI),blockchain,and cloud computing technologies will push the scrap metal intelligent sorting industry to a new level.
  • LI Xiaohui, HU Xinying, GAO Zhijun, SUN Huiying, YU Yahui, LIU Chunxia
    Metallurgical Analysis. 2024, 44(12): 21-26. https://doi.org/10.13228/j.boyuan.issn1000-7571.012518
    It is of great significance for ecological environment protection to determine accurately and efficiently volatile phenol content in sediment. The liquid-solid ratio was controlled at 15∶1. Volatile phenol in the sample was extracted with 10 g/L sodium hydroxide solution after oscillation at 180 r/min for 15 min. Meanwhile, 3.0 g of copper sulfate was added to remove the interference of sulfides in the sample. Thus, the determination of volatile phenol in sediment was realized by flow injection analyzer. The results showed that the mass concentration of volatile phenol in range of 0.02-1.0 mg/L exhibited linear relationship to its corresponding peak area with correlation coefficient of 0.999 9. The limit of detection and lower limit of determination for this method were 0.08 mg/kg and 0.32 mg/kg, respectively. Three sediment samples with different concentrations of volatile phenol content in sediment were determined according to the proposed method, and the relative standard deviations (RSD, n=6) of determination results were between 0.83% and 1.4%. Two types of sediment sample were selected for recovery tests with three content levels, respectively. The recoveries were between 93% and 104%. The contents of volatile phenol in six sediment samples were determined according to the proposed method as well as 4-ampyrone spectrophotometry in standard method of HJ 998-2018. The results of the two above methods were basically consistent.
  • XU Hua, ZENG Zhiping, SHI Yihua, CHEN Chao, CHEN Jiarong
    Metallurgical Analysis. 2024, 44(12): 66-71. https://doi.org/10.13228/j.boyuan.issn1000-7571.012539
    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%.
  • ZHOU Wei, YANG Jingwei, WANG Xuehua, SUN Ye, WANG Runpeng, HE Yuan
    Metallurgical Analysis. 2024, 44(8): 27-33. https://doi.org/10.13228/j.boyuan.issn1000-7571.012511
    To enhance the development and utilization of metal materials, the precise control of physical properties and mechanical performance of metal materials is crucial, wherein the hydrogen plays a particularly key role in influencing these aspects. In this paper, the impact and hazards of hydrogen on the performance of metal materials were summarized. The methods for determining hydrogen content in metal materials in recent years were introduced, mainly including physicochemical method, tube furnace heating-thermal conductivity/infrared method, inert gas protection pulse furnace heating-thermal conductivity/infrared method, inert gas protection pulse furnace heating-mass spectrometry method, thermal desorption-mass spectrometry method, etc. The corresponding analysis principles, instrument structures, and technical characteristics were summarized. The review of applicable detection objects, analysis range, detection limits, and other specifications could enable the technicians in relevant fields to have a comprehensive understanding of hydrogen content detection in metal materials.
  • BAI Jian, QU Zhi, ZHANG Yunfeng, REN Xudong
    Metallurgical Analysis. 2024, 44(12): 40-46. https://doi.org/10.13228/j.boyuan.issn1000-7571.012545
    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.
  • ZHAO Rui, ZHONG Zhenqian, FU Hang
    Metallurgical Analysis. 2024, 44(12): 84-92. https://doi.org/10.13228/j.boyuan.issn1000-7571.012501
    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.
  • XIA Xiang, LU Haichuan, DING Yang, GONG Cang, LIU Tao, LIAO Xuanzhe
    Metallurgical Analysis. 2025, 45(2): 25-33. https://doi.org/10.13228/j.boyuan.issn1000-7571.012597
    Accurate determination of trace element contents, including rare earths, in mudstone can be used to assess its potential as an energy resource, serving geological research and the strategic action for a new round of mineral exploration breakthroughs. In this paper, the mudstone sample was treated using an open acid digestion method with a five-acid system of nitric acid, hydrochloric acid, hydrofluoric acid, perchloric acid, and sulfuric acid. A mixed solution of hydrogen peroxide and aqua regia was added for extraction. Rh and Re were used as internal standards for correction. The method for the determination of 33 elements in mudstone including rare earths (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y, Be, Mn, Co, Ni, Cu, Zn, Rb, Sr, Mo, Tl, Pb, Bi, Th, U, Ti, Nb, and Ta) by inductively coupled plasma mass spectrometry (ICP-MS) was established. The results showed that the linear correlation coefficients of the calibration curves for 33 elements were all greater than 0.999 5. The limits of detection and limits of quantification in this method were 0.000 1-0.9 μg/g and 0.000 4-3.6 μg/g, respectively. GBW07104 and five mudstone samples collected from the Turpan-Hami Basin in Shanshan, Xinjiang, were selected. The contents of 33 elements including rare earths were determined according to the experimental method. The results showed that the relative standard deviations (RSD,n=12) of the measurement results for each element ranged from 0.16% to 9.9%, which could meet the requirement of RSD ≤ 10% specified in DZ/T 0011-2015. The certified reference materials of rock (GBW07103 and GBW07104) with similar compositions to the mudstone samples were selected. The contents of 33 elements including rare earths were determined according to the experimental method. The results showed that the measured values of each element were basically consistent with the certified values. The logarithmic differences (Δlg) ranged from 0.00 to 0.08, which could meet the requirement of Δlg≤ 0.11 specified in DZ/T 0011-2015. Two mudstone samples were measured according to the experimental method, and a certain amount of mixed standard solution was added to each sample to conduct the recovery experiments. The results showed that the spiked recoveries of 33 elements including rare earths in the mudstone samples ranged from 92% to 110%, which could meet the requirement of 90%-110% specified in DZ/T 0130-2006 Specification for Quality Management of Geological and Mineral Laboratory Testing.
  • LIU Minghong, XIONG Dinggan, XIAO Juan, YUAN Qi
    Metallurgical Analysis. 2025, 45(2): 70-75. https://doi.org/10.13228/j.boyuan.issn1000-7571.012567
    At present, the determination of tantalum pentoxide and niobium pentoxide in tantalum-iron and niobium-iron concentrate usually adopts gravimetric method, while the determination of titanium dioxide adopts diantipyrylmethane spectrophotometry or inductively coupled plasma atomic emission spectrometry (ICP-AES). However, these determination methods have long operation procedures, and the sample cannot be determined simultaneously in once sample preparation, which hardly meet the requirements of detection efficiency. In this study, the determination method of tantalum pentoxide, niobium pentoxide and titanium dioxide in tantalum-iron and niobium-iron concentrates by wavelength dispersive X-ray fluorescence spectrometry (WDXRF) with fusion sample preparation was established. The working parameters of the instrument were optimized by experiments, and the melting temperature and time were studied. It was found that the optimal melting temperature and time were 1 100 ℃ and 10 min, respectively. The fluidity of melt flow good, the test piece was uniform without non-melt. In addition, the effects of internal standard correction and direct determination on the linear correlation coefficient of the calibration curve were compared. The results showed that the linear correlation coefficient of the calibration curve of tantalum pentoxide was significantly improved after correction with hafnium dioxide. There was no significant difference in the linear correlation coefficient of the calibration curve using internal standard and direct determination for niobium pentoxide and titanium dioxide. The contents of tantalum pentoxide, niobium pentoxide and titanium dioxide in three tantalum-iron and niobium-iron concentrate samples were determined according to the experimental method. The relative standard deviations (RSD, n=9) of determination results were less than 3%. The components of tantalum-iron and niobium-iron concentrate samples were determined by this method and the chemical wet method, and there was no significant difference in the results.
  • SONG Xiaoran, NIU Guanghui, TANG Yue, XU Yingtong, LIN Qingyu, DUAN Yixiang
    Metallurgical Analysis. 2024, 44(9): 8-13. https://doi.org/10.13228/j.boyuan.issn1000-7571.012503
    In order to improve the flexible analysis capability of laser-induced breakdown spectroscopy(LIBS) under various extreme environments, the miniaturization design of remote LIBS instrument was realized in this study. The instrument adopted modular design, and the tripod head was used as base support. It was applicable for the flexible detection and analysis of remote targets. 8 certified reference materials of alloy steel were used as the experimental subject. The spectral acquisition was carried out under the condition of 2 m. 3 elements in certified reference materials, including Si, Mo and Cr, were quantitatively analyzed. The quantitative models of 3 elements were established by random forest (RF) algorithm, and the coefficients of determination were 0.999 8, 0.998 8 and 0.999 1, respectively. During the model validation, the minimum relative errors of predicted contents of 3 elements (Si, Mo and Cr) in validation samples were 14.6%, 12.9% and 11.6%, respectively. The developed miniaturized remote laser-induced breakdown spectroscopy instrument showed good remote quantitative detection capability.
  • GAO Yanqiang, QI Wei, LIU Yanhui, CHANG Limin, ZHAO Liuwei
    Metallurgical Analysis. 2025, 45(2): 76-81. https://doi.org/10.13228/j.boyuan.issn1000-7571.012582
    The chemical composition of refined slag in iron and steel metallurgical enterprises is generally determined by X-ray fluorescence spectrometry (XRF). Although there are national standard methods for reference, the analysis speed cannot meet the production requirements in front of the smelting furnace. In this study, the sample was prepared by pressed powder pellet method. The grinding time was 40 s, the pressure was 40 MPa, and the holding time was 40 s. Eight self-made refined slag samples were selected as calibration samples to establish the calibration curve. The method for determination of eight major components in refined slag, including silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, phosphorus pentoxide, manganese oxide, titanium dioxide, and iron, was established by XRF with pressed powder pellet sample preparation. The linear correlation coefficients of calibration curves of components were all greater than 0.98. The contents of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, phosphorus pentoxide, manganese oxide, titanium dioxide, and iron in the refined slag sample were determined according to the experimental method. The relative standard deviations (RSD, n=11) of determination results were all less than 0.06%. Three refined slag samples were determined according to the experimental method, and the measured results were consistent with those obtained by the chemical wet methods (where, the content of silicon dioxide was determined by perchloric acid dehydration gravimetry-silicon molybdenum blue spectrophotometry; the contents of aluminum oxide and calcium oxide were determined by EDTA titration; the contents of magnesium oxide, phosphorus pentoxide, manganese oxide, titanium dioxide, and iron were analyzed by inductively coupled plasma atomic emission spectrometry).
  • LI Jing, DING Dongmei
    Metallurgical Analysis. 2024, 44(12): 60-65. https://doi.org/10.13228/j.boyuan.issn1000-7571.012534
    It is of great significance to determine chromium (Ⅵ) accurately in site soil for the management and remediation of contaminated site. Alkali solution extraction-flame atomic absorption spectrometry is one of the main analysis methods for determination of chromium (Ⅵ) in site soil. The certified reference materials and actual samples of site soil were used as research object, and the effects of heating method, stirring speed, liquid-solid ratio and reducing remediation reagent on the determination of chromium (Ⅵ) were investigated. The results showed that the extraction of chromium (Ⅵ) in site soil was more complete when the water bath heating was used, and the stability of determination results were better than that of electrical heating. The stirring rate could significantly affect the determination results of chromium (Ⅵ), and the continuous and steady medium speed stirring showed best effect. Under normal conditions, the liquid-solid ratio of 10∶1 could satisfy the effective extraction of chromium (Ⅵ) in conventional soil samples. However, for the site soil samples with chromium (Ⅵ) content exceeding the upper limit of linear range of calibration curve, the optimal liquid-solid ratio should be obtained by reducing sample mass to ensure the accuracy and reliability of determination results. The reducing remediation reagent had negative interference with the standard addition tests of chromium (Ⅵ). Hydrogen peroxide was added before extraction followed by ultrasonic reaction at room temperature for 5 min. It could change the reducing properties of sample matrix, and meanwhile, keep the chemical form stability of chromium (Ⅵ) in soil sample. The spiked recoveries of chromium (Ⅵ) increased to 75.0%-97.5%. Therefore, the interference of reducing remediation reagent with the spiked recovery test of chromium (Ⅵ) could be effectively eliminated.
  • PAN Hongtao, LI Zhaoguo, ZHANG Youyu
    Metallurgical Analysis. 2024, 44(12): 78-83. https://doi.org/10.13228/j.boyuan.issn1000-7571.012506
    The oxide scale samples of full hydrogen batch annealing steel coil of 40Cr13Mo and 40Cr13 produced by the same process were analyzed by scanning electron microscopy (SEM), X-ray energy dispersion spectrum (EDS) and X-ray diffraction (XRD). The results showed that the oxide scale of stainless steel 40Cr13Mo was dense with low peeling degree due to the addition of Mo. Only few small defects were observed inside. There was pressure stress in some parts and the strength was slightly higher than that of oxide scale. The bonding regions with matrix were colloidal, and there were “small wedge prominences” of 2FeO·SiO2 (fayalite) with pinning depth of 0.81 μm. The oxide scale thickness was small but the range was large, and the bonding surface with matrix was uneven. The energy distribution trend of Cr was consistent with O in EDS surface scanning. The high-level regions accounted for above 90%, which were distributed in middle and lining of oxide scale. The middle-level regions of 10% were distributed in periphery of oxide scale, and there were no low-level regions. In the bonding regions with matrix, Si showed continuous middle-level stripes with width of 3 μm, and there were 3 μm high-level spots in stripes. The reduction process of oxide scale with hydrogen lagged behind seriously. The phases were mainly FeCr2O4 and FeO. Their contentsaccounted for 90.2% (mass fraction, the same above), and the contents of Fe, Cr and Cr0.7Fe0.3 were only 9.6%.
  • XIA Chuanbo, ZHENG Jianye, TIAN Xinglei, WANG Jingyun LIU Jiwei, CHENG Xuehai
    Metallurgical Analysis. 2025, 45(2): 18-24. https://doi.org/10.13228/j.boyuan.issn1000-7571.012556
    Rare metal ores are often associated with various dispersed metal elements such as zirconium, hafnium, uranium, thorium, thallium, gallium, tungsten and tin. However, there are few literatures on the related testing methods, and the existing rare metal ore reference materials also are in lack of certified values for associated elements such as zirconium, hafnium, gallium, thallium, uranium, and thorium. In this study, six types of rare metal ore reference materials were digested with nitric acid-hydrofluoric acid system with high pressure closed digestion. The residue was redissolved with aqua regia (1+1). The determination of zirconium, hafnium, gallium, thallium, uranium and thorium by inductively coupled plasma mass spectrometry (ICP-MS) was realized. The reference values of six associated elements in six rare metal ore reference materials were provided. The digestion effects of rare metal ore reference materials by three methods, namely open digestion with nitric acid-hydrofluoric acid-perchloric acid, open digestion with nitric acid-hydrochloric acid-hydrofluoric acid-perchloric acid, and closed digestion with nitric acid-hydrofluoric acid, were compared. The results showed that the sample could be completely digested by the high pressure closed digestion method. The rare metal ore reference materials were selected to investigate the redissolution effect by aqua regia (1+1). The results showed that the measurement values of zirconium and hafnium after redissolution with aqua regia (1+1) were consistent with those obtained by alkali fusion-ICP-MS and X-ray fluorescence spectrometry (XRF). It indicated that the hydrolysis problem of zirconium and hafnium could be solved using the oxidability of nitric acid and complexation effect of chlorine ion. The linear correlation coefficients of calibration curves of elements in this method were all higher than 0.999 9. The limit of detection and limit of quantification were 0.01-0.04 μg/g and 0.04-0.16 μg/g, respectively. The proposed method was applied for the determination of elements in certified reference materials GBW07103 (granite), GBW07832 (dispersed element ore), GBW07834 (dispersed element ore) and GBW04132 (sandstone uranium ore) with similar matrix and contents of testing elements. The relative standard deviations (RSD, n=8) of determination results were between 1.5% and 6.4%, which could meet the requirements in DZ/T 0130-2006 The specification of testing quality management for geological laboratories. The measurement results were basically consistent with the certified values of reference materials, and the relative errors (RE) were between -2.6% and 3.2%. The contents of zirconium, hafnium, gallium, thallium, uranium, and thorium in reference materials of rare metal ore (GBW07152-GBW07155, GBW07184 and GBW07185) were determined according to the experimental method, and the reference values of elements were provided. These data could be used as a reference for other studies and provided a foundation for further collaborative study and other work.
  • LU Chaochao, SUN Xuejiao, FANG Jinlin, DONG Bingcheng, WU Hongjian
    Metallurgical Analysis. 2025, 45(2): 10-17. https://doi.org/10.13228/j.boyuan.issn1000-7571.012439
    In the research of inclusions control, how to accurately characterize and analyze the inclusions in steel is the key link. Focused ion beam (FIB)-scanning electron microscopy (SEM) can realize the internal structure analysis and three-dimensional reconstruction of inclusions in steel as well as the sample preparation for transmission electron microscopy (TEM), so it has become an important detection method for the study of inclusions in alloy steel. In this paper, the working principle of FIB-SEM and its application in internal structure analysis, three-dimensional reconstruction of inclusions and TME sample preparation were discussed. By examining the structure, composition and distribution of inclusions in low alloy steel, high strength steel, bis steel and bearing steel, the formation process and reason of various inclusions such as magnesium aluminum spinel and sulfide complex inclusions, nitride and manganese sulfide complex inclusions, calcium aluminate and titanium nitride complex inclusions were analyzed. Through the three-dimensional reconstruction of inclusions in bearing steel, the size, three-dimensional morphology and spatial distribution of (Ti,V)N solid solution inclusions in steel were obtained. Moreover, the sample preparation for TEM was conducted. This paper provided method reference and theoretical reference for solving the problem of tracing the inclusions in alloy steel.
  • LIAN Weijie, ZHAI Yuxin, TIAN Zhaoyong, LI Shuang, MA Lan
    Metallurgical Analysis. 2025, 45(2): 56-63. https://doi.org/10.13228/j.boyuan.issn1000-7571.012612
    The accurate determination of alloying elements and impurities in titanium alloy is important for the performance study and quality control of alloy products. In experiments, the samples were prepared by turning or milling. After correcting the interference of coexisting elements, the analytical lines of each element were selected, i.e., Al 396.110 nm and Al 394.403 nm, Cr 425.433 nm and Cr 313.210 nm, Cu 324.710 nm and Cu 510.514 nm, Fe 259.940 nm, Mn 257.660 nm and Mn 293.310 nm, Mo 386.411mm and Mo 281.610 nm, Ni 231.604 nm, Si 288.158 nm, Sn 147.510 nm and Sn 317.505 nm, V 437.924 nm and V 290.810 nm, Zr 357.247 nm. A series of standard samples of titanium alloy for spectral analysis were used to draw the calibration curves, which were then fitted and optimized. A method for the determination of 11 alloying elements and impurities including aluminum, chromium, copper, iron, manganese, molybdenum, nickel, silicon, tin, vanadium and zirconium by spark discharge atomic emission spectrometry was established. The determination coefficients of the calibration curves were all greater than 0.999. The limits of detection were between 0.000 03% and 0.002 94%. The contents of eleven elements in the standard samples of titanium alloy were determined according to the experimental method, the relative standard deviations (RSD, n=11) of determination results were between 0.31% and 4.9%. The absolute value of relative errors (RE) between the determination results and standard values of elements were not more than 8.1%. Three grades of titanium alloy samples were analyzed and compared. The samples were determined according to the experimental method, and the found results were basically consistent with those obtained by YS/T 1262-2018.
  • ZHANG Chuang, CHEN Xiongfei, GAO Lin, XU Qing, ZHANG Jing, LIU Mei
    Metallurgical Analysis. 2025, 45(2): 87-93. https://doi.org/10.13228/j.boyuan.issn1000-7571.012592
    The accurate determination of potassium content in tungsten-rhenium alloys is of great significance for studying the high-temperature properties of materials and the room temperature plasticity after recrystallization. In this study, the sample was dissolved with nitric acid and hydrofluoric acid. The cesium chloride solution was added as an ionizing agent to suppress the ionization of potassium and eliminate ionization interference. A method for the determination of potassium with mass fraction of 0.000 5%-0.010% in tungsten-rhenium alloy by flame atomic absorption spectrometry (FAAS) was established. The interference test showed that tungsten or rhenium matrices had a significant impact on the measurement. Therefore, the matrix matching method was used to draw calibration curves to overcome the matrix effect of tungsten or rhenium. The influence of other elements in the sample, except for the matrix tungsten and rhenium, on the determination could be ignored. The experimental results showed that the correlation coefficients of calibration curves for sample WRe5 and WRe25 were 0.999 8 and 0.999 6, respectively, and the characteristic concentrations of potassium were both 0.007 6 μg/mL. The precision tests were conducted using four tungsten-rhenium alloy samples with different potassium content levels according to the experimental methods, and the relative standard deviations (RSD, n=9) of the measurement results ranged from 1.7% to 3.1%. The contents of potassium in WRe5 and WRe25 tungsten-rhenium alloy samples were determined according to the experimental method. Different amounts of 1 μg/mL potassium standard solution were added for the spiked recovery tests, with recovery rates ranging from 98% to 104%. The inductively coupled plasma mass spectrometry (ICP-MS) was used for method comparison and validation. The t-test analysis showed that there was no significant difference between the ICP-MS and the experimental method.