Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in therm...Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.展开更多
One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In genera...One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In general, gold refractory ores occurs in various types of deposits associated with a range of minerals. Among the refractory ores, the sulfide type is the most common. The methodology employed in the mining process depends on the mode of occurrence of the ore and on the particle size, shape and degree of purity of the auriferous species. We have undertaken a mineralogical investigation of a representative sample of a complex gold mining ore collected in the municipality of Princesa Isabel, Paraiba, Brazil, using X-ray fluorescence spectrometry, X-ray diffractometry, infrared spectroscopy, inductively coupled plasma-atomic emission spectrometry and the Fire Assay. The results showed that the arsenic content of the ore was closely related to the gold content, and that the occurrence of “invisible gold” was associated primarily with pyrite and secondarily with arsenopyrite. The sulfur content of the ore was directly related to its refractoriness. It is concluded that gold mineralization in the study area is mainly of the gold-quartz-sulfide veins (lode gold), while the gold found in the mini-fractures of the deposits is probably associated with the hydrothermal processes that occurred in the region.展开更多
Organic geochemistry methods such as high temperature combustion, Rock-Eval pyrolysis and gas analysis were used to analyze oil shale from Babouri-Figuil Basin. Results show that the average content of organic matter ...Organic geochemistry methods such as high temperature combustion, Rock-Eval pyrolysis and gas analysis were used to analyze oil shale from Babouri-Figuil Basin. Results show that the average content of organic matter is 36.25 %wt, while that of mineral matter is 63.75 %wt. The total organic carbon (TOC) is between 15.93 %wt and 26.82 %wt. The HI vs. Tmax diagram indicates an immature Type I kerogen. The average value of the oil potential (S2b) is 149.95 mg HC/g rock. The gases obtained by retort process are H2, CO2, CO and CnH2n, CnH2n+2. Finally, it emerges that, the organic matter of Babouri-Figuil shales was immature or has just reached the beginning of the oil window. The mineralogical study of Babouri-Figuil oil shale has been carried out by means of XRD (X-Ray Diffractometry) and XRF (X-Ray Fluorescence spectrometry). The results show that mineral matrix contains silica, carbonates, sulphates, oxides and clay minerals. Besides, compounds contain metals and metalloids like Fe, In, Ca. The main oxides are SiO2 (majority), CaO, Fe2O3, Al2O3, SO3, and K2O.展开更多
Excess calcium(Ca)in soils of semi-arid and arid regions has negative effects on soil structure and chemical properties,which limits the crop root growth as well as the availability of soil water and nutrients.Quantif...Excess calcium(Ca)in soils of semi-arid and arid regions has negative effects on soil structure and chemical properties,which limits the crop root growth as well as the availability of soil water and nutrients.Quantifying the spatial variability of soil Ca contents may reveal factors influencing soil erosion and provide a basis for site-specific soil and crop management in semi-arid regions.This study sought to assess the spatial variability of soil Ca in relation to topography,hydraulic attributes,and soil types for precision soil and crop management in a 194-ha production field in the Southern High Plains of Texas,USA.Soils at four depth increments(0-2,0-15,15-30,and 30-60 cm)were sampled at 232 points in the spring of 2017.The Ca content of each sample was determined with a DP-6000 Delta Premium portable X-ray fluorescence(PXRF)spectrometer.Elevation data was obtained using a real-time kinematic GPS receiver with centimeter-level accuracy.A digital elevation model(DEM)was derived from the elevation data,and topographic and hydraulic attributes were generated from this DEM.A generalized least-squares model was then developed to assess the relationship between soil Ca contents of the four layers and the topographic and hydraulic attributes.Results showed that topographic attributes,especially slope and elevation,had a significant effect on soil Ca content at different depths(P<0.01).In addition,hydraulic attributes,especially flow length and sediment transport index(STI),had a significant effect on the spatial distribution of soil Ca.Spatial variability of soil Ca and its relationships with topographic and hydraulic attributes and soil types indicated that surface soil loss may occur due to water or wind erosion,especially on susceptible soils with high slopes.Therefore,this study suggests that the application of PXRF in assessing soil Ca content can potentially facilitate a new method for soil erosion evaluation in semi-arid lands.The results of this study provide valuable information for site-specific soil conservation and crop management.展开更多
Heavy metal contamination in the El-Gharbia Governorate(District)of Egypt was identified by using remote sensing,Geographical Information Systems(GIS),and X-ray fluorescence(XRF)spectrometry as the main research tools...Heavy metal contamination in the El-Gharbia Governorate(District)of Egypt was identified by using remote sensing,Geographical Information Systems(GIS),and X-ray fluorescence(XRF)spectrometry as the main research tools.Digital Elevation Model(DEM),Landsat 8 and contour map images were used to map the landforms.Different physiographic units in the study area are represented by nine soil profiles.X-ray fluorescence spectrometry(XRF)was used for geochemical analysis of 33 soil samples.Vanadium(V),nickel(Ni),chromium(Cr),copper(Cu)and zinc(Zn)concentrations were measured and they all exceeded the average global concentrations identified by Wedepohl(1995).Ni and Cr concentrations exceeded recommended values in all soil profile horizons(Canadian Soil Quality Guidelines,2007),while Cu had a variable distribution.Zn concentrations are under recommended concentration limits in most soil samples.Contamination Factor,Pollution Load Index and Degree of Contamination indices were used to assess the environmental risks of heavy metal contamination from the soils.All analysed metals pose some potential hazard and pollution levels were particularly high near industrial and urban areas.展开更多
基金supported by National Energy R&D Center of Petroleum Refining Technology of China(RIPP,SINOPEC)National Key Research and Development Program of China(No.2017YFA0304203)+5 种基金Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R70)National Natural Science Foundation of China(Nos.61975103,61875108,61775125 and 11434007)Industrial Application Innovation Project(No.627010407)Scientific and Technological Innovation Project of Shanxi Gemeng US-China Clean Energy R&D Center Co.,Ltd111 Project(D18001)Fund for Shanxi‘1331KSC’。
文摘Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.
基金the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq,grant no.550261/2010-9)for financial support
文摘One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In general, gold refractory ores occurs in various types of deposits associated with a range of minerals. Among the refractory ores, the sulfide type is the most common. The methodology employed in the mining process depends on the mode of occurrence of the ore and on the particle size, shape and degree of purity of the auriferous species. We have undertaken a mineralogical investigation of a representative sample of a complex gold mining ore collected in the municipality of Princesa Isabel, Paraiba, Brazil, using X-ray fluorescence spectrometry, X-ray diffractometry, infrared spectroscopy, inductively coupled plasma-atomic emission spectrometry and the Fire Assay. The results showed that the arsenic content of the ore was closely related to the gold content, and that the occurrence of “invisible gold” was associated primarily with pyrite and secondarily with arsenopyrite. The sulfur content of the ore was directly related to its refractoriness. It is concluded that gold mineralization in the study area is mainly of the gold-quartz-sulfide veins (lode gold), while the gold found in the mini-fractures of the deposits is probably associated with the hydrothermal processes that occurred in the region.
基金financial and material supports from the“University Commission for Development”(UCD)and University of Liege-Belgium(ULg).
文摘Organic geochemistry methods such as high temperature combustion, Rock-Eval pyrolysis and gas analysis were used to analyze oil shale from Babouri-Figuil Basin. Results show that the average content of organic matter is 36.25 %wt, while that of mineral matter is 63.75 %wt. The total organic carbon (TOC) is between 15.93 %wt and 26.82 %wt. The HI vs. Tmax diagram indicates an immature Type I kerogen. The average value of the oil potential (S2b) is 149.95 mg HC/g rock. The gases obtained by retort process are H2, CO2, CO and CnH2n, CnH2n+2. Finally, it emerges that, the organic matter of Babouri-Figuil shales was immature or has just reached the beginning of the oil window. The mineralogical study of Babouri-Figuil oil shale has been carried out by means of XRD (X-Ray Diffractometry) and XRF (X-Ray Fluorescence spectrometry). The results show that mineral matrix contains silica, carbonates, sulphates, oxides and clay minerals. Besides, compounds contain metals and metalloids like Fe, In, Ca. The main oxides are SiO2 (majority), CaO, Fe2O3, Al2O3, SO3, and K2O.
基金supported by Texas Tech UniversityCotton IncorporatedTexas Water Development Board,USA。
文摘Excess calcium(Ca)in soils of semi-arid and arid regions has negative effects on soil structure and chemical properties,which limits the crop root growth as well as the availability of soil water and nutrients.Quantifying the spatial variability of soil Ca contents may reveal factors influencing soil erosion and provide a basis for site-specific soil and crop management in semi-arid regions.This study sought to assess the spatial variability of soil Ca in relation to topography,hydraulic attributes,and soil types for precision soil and crop management in a 194-ha production field in the Southern High Plains of Texas,USA.Soils at four depth increments(0-2,0-15,15-30,and 30-60 cm)were sampled at 232 points in the spring of 2017.The Ca content of each sample was determined with a DP-6000 Delta Premium portable X-ray fluorescence(PXRF)spectrometer.Elevation data was obtained using a real-time kinematic GPS receiver with centimeter-level accuracy.A digital elevation model(DEM)was derived from the elevation data,and topographic and hydraulic attributes were generated from this DEM.A generalized least-squares model was then developed to assess the relationship between soil Ca contents of the four layers and the topographic and hydraulic attributes.Results showed that topographic attributes,especially slope and elevation,had a significant effect on soil Ca content at different depths(P<0.01).In addition,hydraulic attributes,especially flow length and sediment transport index(STI),had a significant effect on the spatial distribution of soil Ca.Spatial variability of soil Ca and its relationships with topographic and hydraulic attributes and soil types indicated that surface soil loss may occur due to water or wind erosion,especially on susceptible soils with high slopes.Therefore,this study suggests that the application of PXRF in assessing soil Ca content can potentially facilitate a new method for soil erosion evaluation in semi-arid lands.The results of this study provide valuable information for site-specific soil conservation and crop management.
文摘Heavy metal contamination in the El-Gharbia Governorate(District)of Egypt was identified by using remote sensing,Geographical Information Systems(GIS),and X-ray fluorescence(XRF)spectrometry as the main research tools.Digital Elevation Model(DEM),Landsat 8 and contour map images were used to map the landforms.Different physiographic units in the study area are represented by nine soil profiles.X-ray fluorescence spectrometry(XRF)was used for geochemical analysis of 33 soil samples.Vanadium(V),nickel(Ni),chromium(Cr),copper(Cu)and zinc(Zn)concentrations were measured and they all exceeded the average global concentrations identified by Wedepohl(1995).Ni and Cr concentrations exceeded recommended values in all soil profile horizons(Canadian Soil Quality Guidelines,2007),while Cu had a variable distribution.Zn concentrations are under recommended concentration limits in most soil samples.Contamination Factor,Pollution Load Index and Degree of Contamination indices were used to assess the environmental risks of heavy metal contamination from the soils.All analysed metals pose some potential hazard and pollution levels were particularly high near industrial and urban areas.
