便携式X-荧光仪与ICP-AES联同检测废塑料金属涂层含量

提出利用便携式X-荧光仪与ICP-AES联同检测废塑料金属涂层中5种金属元素含量的方法。以稳定性为优化原则选择仪器的工作条件,研究共存元素的影响和酸度效应,铝、铜、锌、镍、铬等金属元素检出限为0.006%~0.009%,相对标准偏差为0.5%~1.5%,回收率为90%~106%。该方法为控制废塑料金属涂层产生的危害和污染提供更为合理的检测手段,已应用于实际检测工作当中。

X-射线荧光分析仪常见故障及排除方法

本文详细介绍了岛津MXF-2100型X-射线荧光分析仪测量原理、结构、常见故障、排除方法及维护注意事项。

X—荧光仪用混合型离子交换树脂失效分析与再生

本文研究了X-荧光仪用混合型离子交换树脂失效原因，介绍了失效树脂的再生方法。

X-射线荧光光谱法测定冶金原辅料中的磷

利用不同的化学融样方法确定铁合金、铁精粉、球团矿、白灰中的磷含量,结合X-射线荧光工作曲线实现了冶金企业原辅料中有害元素磷的在线快速、准确分析,对冶金生产单位开发新品种、改进生产工艺起了重要作用。

Use of sampling based correction for non-radioactivity X-ray energy calibration

As the requirement of non-radioactivity measurement has increased in recent years,various energy cali- bration methods applied in portable X-ray fluorescence (XRF) spectrometers have been developed. In this paper,a sampling based correction energy calibration has been discussed. In this method both history information and current state of the instrument are considered and relative high precision and reliability can be obtained.

Extraction of nickel from molybdenum leaching residue of metalliferous black shale by segregation roasting and acid leaching

The recovery of nickel from molybdenum leach residue by the process of segregation roasting-sulfuric acid leaching-solvent extraction was investigated. The residue was characterized by microscopic investigations, using X-ray fluorescence spectrometry （XRF） and X-ray diffractometry （XRD） techniques and the residue after segregation roasting was characterized by chemical phase analysis method. A series of experiments were conducted to examine the mass ratio of activated carbon （AC） to the residue, segregation roasting time and temperature, sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, addition amount of 30% H2O2, stirring speed （a constant） on the leaching efficiency of nickel. A maximum nickel leaching efficiency of 90.5% is achieved with the mass ratio of AC to the residue of 1：2.5, segregation roasting time of 2 h, segregation roasting temperature of 850 ℃, sulfuric acid concentration of 4.5 mol/L, liquid-to-solid ratio of 6：1, leaching time of 5 h, leaching temperature of 80 ℃, addition of 30% H202 of 0.6 mL for 1 g dry residue. Under these optimized conditions, the average leaching efficiency of nickel is 89.3%. The nickel extraction efficiency in the examined conditions is about 99.6%, and the nickel stripping efficiency in the examined conditions is about 99.2%.

On the genesis of granite pits on top of the Shigujian Peak of the Dayangshan Mountain in Jinyun County,Zhejiang Province

On top of Shigujian Peak(1477 m a.s.l.) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to around one meter and depth from 10 cm to 45 cm are found on rock surface.These pits mainly appear on the NE and SE sides, and their drainage mouths are in the same direction.The identification results through micropolariscope and X-ray fluorescence spectrometer reveal that bedrock of pits is from middle to fine-grained moyite being apt to be weathered and modified.In Dayangshan region the annual mean temperature is 9.2℃ and annual precipitation is over 1700 mm.On the one hand, there always experiences a period of periglacial action with temperature oscillating near 0℃ for 4 months, i.e., from December to March next year.As a consequence, the freezing-thawing cycles may be remarkable to disintegrate the bedrock.On the other hand, the windward slope of Shigujian Peak meets typhoon of over force 10 on the Beaufort scale in summer, therefore, the blowing makes suspending sands or pebbles grind in swirling form.Based on field investigation and periglacial geomorphic theory, the pits on top of Shigujian Peak are attributed to freez-ing-thawing of periglacial action.Meanwhile, storm and strong wind accelerate the process.Observation shows that both the actions are still undergoing and variant directions of wind are the main cause for making different shapes of the pits.Because the top of Shigujian is 1500 m lower than the present snow line, some scholars considered that"glacial pothole"formed in the Quaternary is hard to work, even though in the Last Glacial Maximum(LGM).

Prediction of XRF analyzers error for elements on-line assaying using Kalman Filter

Determination of chemical elements assay plays an important role in mineral processing operations.This factor is used to control process accuracy,recovery calculation and plant profitability.The new assaying methods including chemical methods,X-ray fluorescence and atomic absorption spectrometry are advanced and accurate.However,in some applications,such as on-line assaying process,high accuracy is required.In this paper,an algorithm based on Kalman Filter is presented to predict on-line XRF errors.This research has been carried out on the basis of based the industrial real data collection for evaluating the performance of the presented algorithm.The measurements and analysis for this study were conducted at the Sarcheshmeh Copper Concentrator Plant located in Iran.The quality of the obtained results was very satisfied;so that the RMS errors of prediction obtained for Cu and Mo grade assaying errors in rougher feed were less than 0.039 and 0.002 and in final flotation concentration less than 0.58 and 0.074,respectively.The results indicate that the mentioned method is quite accurate to reduce the on-line XRF errors measurement.

In-Situ Differentiation of Acidic and Non-Acidic Tundra via Portable X-ray Fluorescence (PXRF) Spectrometry

Frozen soils or those with permafrost cover large areas of the earth's surface and support unique vegetative ecosystems. Plants growing in such harsh conditions have adapted to small niches, which allow them to survive. In northern Alaska, USA, both moist acidic and non-acidic tundra occur, yet determination of frozen soil p Hs currently requires thawing of the soil so that electrometric pH methods can be utilized. Contrariwise, a portable X-ray fluorescence(PXRF) spectrometer was used in this study to assess elemental abundances and relate those characteristics to soil pH through predictive multiple linear regressions. Two operational modes, Soil Mode and Geochem Mode, were utilized to scan frozen soils in-situ and under laboratory conditions, respectively, after soil samples were dried and ground. Results showed that lab scanning produced optimal results with adjusted coefficient of determination(R^2) of 0.88 and 0.33 and root mean squared errors(RMSEs) of 0.87 and 0.34 between elemental data and lab-determined pH for Soil Mode and Geochem Mode, respectively. Even though the presence of ice attenuated fluoresced radiation under field conditions, adjusted R^2 and RMSEs between the datasets still provided reasonable model generalization(e.g., 0.73 and 0.49 for field Geochem Mode). Principal component analysis qualitatively separated multiple sampling sites based on elemental data provided by PXRF, reflecting differences in the chemical composition of the soils studied. Summarily, PXRF can be used for in-situ determination of soil pH in arctic environments without the need for sample modification and thawing. Furthermore, use of PXRF for determination of soil pH may provide higher sample throughput than traditional eletrometric-based methods, while generating elemental data useful for the prediction of multiple soil parameters.

Quantitative analysis of elements (C,N,O,Al,Si and Fe) in polyamide with wavelength dispersive X-ray fluorescence spectrometry

A wavelength dispersive X-ray fluorescence （WD-XRF） spectrometry combined with calibration curve method was estab- lished for simultaneously analyzing low-Z elements （C, N, O） and A1, Si, Fe in polyamide. To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines, polyamide 6 （PA 6, an engineering plastic） was chosen as the study object on account of its common use in industry. The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6. Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C, N, O elements. PA 6 particles were firstly smashed to uniform powder in liquid nitrogen, and then mixed with inorganic standard powders （Fe203, A1203, SIO2, and Na2SiO3）. The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis. The quantitative property of the calibration curve method for each element was re- liable. The limits of detection （S/N≤3） of C, N, O, A1, Si and Fe using WD-XRF were 249, 120, 101, 6.2, 3.3, and 1.8 μg/g, respectively. To confirm the accuracy of the proposed WD-XRF calibration curve method, inductively coupled plasma optical emission spectroscopy （ICP-OES） detection for A1, Si, Fe and elemental analyzer （EA） analysis for C, N, O were utilized. A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.

Cellular Tolerance, Accumulation and Distribution of Cadmium in Leaves of Hyperaccumulator Picris divaricata

Knowledge of cellular metal homeostasis will provide a better understanding of the mechanisms involved in metal tolerance and hyperaccumulation in metal-hyperaccumulating plants. Energy dispersive X-ray spectrometry （EDS） was used to determine the localization of cadmium （Cd） in leaves of the Zn/Cd hyperaccumulator Picris divaricata which had a shoot Cd concentration of 565 mg kg-1 after 2 weeks of growth in solution culture supplying 10μ tmol L^-1 CdCl2. The results indicated that Cd was distributed mainly in the trichomes, upper and lower epidermis and bundle sheath cells, with a relatively low level of Cd in mesophyll cells. Mesophyll protoplasts isolated from leaves remained viable after 24 h exposure to CdCl2 at a concentration up to 1 mmol L^-1, indicating their high tolerance to Cd. The intracellular Cd was visualized by staining with Leadmium Green dye, a cellular permeable Cd fluorescence probe. The results showed that the majority of protoplasts （〉 82%） did not accumulate Cd, with only a minority （〈 18%） showing Cd accumulation. In the Cd-accumulating protoplasts, Cd accumulation was depressed by the addition of Fe^2＋, Mn^2＋ and the metabolic inhibitor carbonyl cyanide m-chlorophenylhydrazone （CCCP）, but not by Ca^2＋ or Zn^2＋. Furthermore, the entire process of Cd uptake from external solution into the cytoplasm and subsequent sequestration into vacuoles was successfully recorded by confocal images. These results suggested that reduced cellular Cd accumulation and efficient Cd vacuolar sequestration in mesophyll cells might be responsible for cellular Cd tolerance and distribution in the leaves of P. divaricata.

Gold Supported on Metal Oxides for Carbon Monoxide Oxidation

Au has been loaded （1% wt.） on different commercial oxide supports （CuO, La2O3, Y2O3, NiO） by three different methods： double impregnation （DIM）, liquid-phase reductive deposition （LPRD）, and ultrasonication （US）. Samples were characterised by N2 adsorption at -196℃, high-resolution transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectrometry, high-angle annular dark-field imaging （Z-contrast）, X-ray diffraction, and temperature programmed reduction. CO oxidation was used as a test reaction to compare the catalytic activities. The best results were obtained with Au loaded by DIM on the NiO support, with an activity of 7.2 × 10^（-4） molco·gAu^（-1）·s^（-1） at room temperature. This is most likely related to the Au nanoparticle size being the smallest in this catalyst （average 4.8 nm）, since it is well known that gold particle size determines the catalytic activity. Other samples, having larger Au particle sizes （in the 2-12 nm range, with average sizes ranging from 4.8 to 6.8 nm）, showed lower activities. Nevertheless, all samples prepared by DIM had activities （from 1.1 × 10^（-4） to 7.2 × 10^（-4） molco·gAu^（-1）·S^（-1）, at room temperature） above those reported in the literature for gold on similar oxide supports. Therefore, this method gives better results than the most usual methods of deposition-precipitation or co-precipitation.