Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of ...Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of hydrogen sulfide(SOH_(2)S) to elemental sulfur(S) has emerged as a sustainable and environmentally friendly solution.Due to its unique properties,iron oxide has been extensively investigated as a catalyst for SOH_(2)S;however,rapid deactivation has remained a significant drawback.The causes of iron oxide-based catalysts deactivation mechanisms in SOH_(2)S,including sulfur or sulfate deposition,the transformation of iron species,sintering and excessive oxygen vacancy formation,and active site loss,are thoroughly examined in this review.By focusing on the deactivation mechanisms,this review aims to provide valuable insights into enhancing the stability and efficiency of iron-based catalysts for SOH_(2)S.展开更多
40Ar-39Ar dating of albite from the Meishan and Taocun iron deposits yields plateau ages of 122.90±0.16 Ma and 124.89±0.30 Ma, and isochron ages of 122.60±0.16 Ma and 124.90±0.29 Ma, respectively. ...40Ar-39Ar dating of albite from the Meishan and Taocun iron deposits yields plateau ages of 122.90±0.16 Ma and 124.89±0.30 Ma, and isochron ages of 122.60±0.16 Ma and 124.90±0.29 Ma, respectively. Phlogopite from the Zhongshan-Gushan ore field has a plateau age of 126.7±0.17 Ma and an isochron age of 127.21±1.63 Ma. Analysis of regional geodynamic evolution of the middle-lower Yangtze River region suggests that the porphyry iron deposits were formed as a result of large-scale lithosphere delamination and strong sinistral strike-slip movement of the Tancheng Lujiang fault zone. The copper, molybdenum and gold deposit system in the middle-lower Yangtze River region was formed during the stress transition period of the eastern China continent.展开更多
Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones (i.e. iron ores) of individual deposits. The assemblage includes magn...Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones (i.e. iron ores) of individual deposits. The assemblage includes magnetite, apatite and actinolite (or diopside). The second type occurs within magnetite-apatite veins in the iron ores. The third type is seen in magnetite-apatite veins and (or) nodules in host rocks (i.e. gabbro-diorite porphyry or gabbro-diorite or pyroxene diorite).The fourth type occurs within apatite-pyrite-quartz veins f'dfing fractures in the Xiangshan Group. Rare earth elements (REE) geochemistry of apatite of the four occurrences in porphyry iron deposits is presented. The REE distribution patterns of apatite are generally similar to those of apatites in the Kiruna-type iron ores, nelsonites. They are enriched in fight REE, with pronounced negative Eu anomalies. The similarity of REE distribution patterns in apatites from various deposits in different locations in the world indicates a common process of formation for various ore types, e.g. immiscibility. Early magmatic apatites contain 3031.48-12080 ×10^-6 REE. Later hydrothermal apatite contains 1958 ×10^-6 REE, indicating that the later hydrothermal ore-forming solution contains lower REE. Although gabbro-diorite porphyry and apatite show similar REE patterns, gabbro-diorite porphyries have no europium anomalies or feeble positive or feeble negative europium anomalies, caused both by reduction environment of mantle source region and by fractionation and crystallization (immiscibility) under a high oxygen fugacity condition. Negative Eu anomalies of apatites were formed possibly due to acquisition of Eu^2+ by earlier diopsite during ore magma cooling. The apatites in the Aoshan and Taishan iron deposits yield a narrow variation range of ^87Sr/^86Sr values from 0.7071 to 0.7073, similar to those of the volcanic and subvolcaulc rocks, indicating that apatites were formed by liquid immiscibility and differentiation of intermediate and basic magmas.展开更多
Long-standing controversy persists over the presence and role of iron-rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron-rich and silica-rich melt inclusions observed in thin-sections ar...Long-standing controversy persists over the presence and role of iron-rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron-rich and silica-rich melt inclusions observed in thin-sections are considered as direct evidence for the presence of iron-rich melt, yet unequivocal outcrop-scale evidence of iron-rich melts are still lacking in volcanic rock-hosted iron deposits. Submarine volcanic rock-hosted iron deposits, which are mainly distributed in the western and eastern Tianshan Mountains in Xinjiang, are important resources of iron ores in China, but it remains unclear whether iron-rich melts have played a role in the mineralization of such iron ores. In this study, we observed abundant iron-rich agglomerates in the brecciated andesite lava of the Heijianshan submarine volcanic rock-hosted iron deposit, Eastern Tianshan, China. The iron-rich agglomerates occur as irregular and angular masses filling fractures of the host brecciated andesite lava. They show concentric potassic alteration with silicification or epidotization rims, indicative of their formation after the wall rocks. The iron-rich agglomerates have porphyritic and hyalopilitic textures, and locally display chilled margins in the contact zone with the host rocks. These features cannot be explained by hydrothermal replacement of wall rocks (brecciated andesite lava) which is free of vesicle and amygdale, rather they indicate direct crystallization of the iron-rich agglomerates from iron-rich melts. We propose that the iron-rich agglomerates were formed by open-space filling of volatile-rich iron-rich melt in fractures of the brecciated andesite lava. The iron-rich agglomerates are compositionally similar to the wall-rock brecciated andesite lava, but have much larger variation. Based on mineral assemblages, the iron-rich agglomerates are subdivided into five types, i.e., albite-magnetite type, albite-K-feldspar- magnetite type, K-feldspar-magnetite type, epidote-magnetite type and quartz-magnetite type, representing that products formed at different stages during the evolution of a magmatic-hydrothermal system. The albite-magnetite type represents the earliest crystallization product from a residual iron- rich melt; the albite-K-feldspar-magnetite and K-feldspar-magnetite types show features of magmatic- hydrothermal transition, whereas the epidote-magnetite and quartz-magnetite types represent products of hydrothermal alteration. The occurrence of iron-rich agglomerates provides macroscopic evidence for the presence of iron-rich melts in the mineralization of the Heijianshan iron deposit. It also indicates that iron mineralization of submarine volcanic rock-hosted iron deposits is genetically related to hydrothermal fluids derived from iron-rich melts.展开更多
Brain iron deposition has been proposed to play an important role in the pathophysiology of Alzheimer disease(AD).The aim of this study was to investigate the correlation of brain iron accumulation with the severity...Brain iron deposition has been proposed to play an important role in the pathophysiology of Alzheimer disease(AD).The aim of this study was to investigate the correlation of brain iron accumulation with the severity of cognitive impairment in patients with AD by using quantitative MR relaxation rate R2' measurements.Fifteen patients with AD,15 age-and sex-matched healthy controls,and 30 healthy volunteers underwent 1.5T MR multi-echo T2 mapping and T2* mapping for the measurement of transverse relaxation rate R2'(R2'=R2*-R2).We statistically analyzed the R2' and iron concentrations of bilateral hippocampus(HP),parietal cortex(PC),frontal white matter(FWM),putamen(PU),caudate nucleus(CN),thalamus(TH),red nucleus(RN),substantia nigra(SN),and dentate nucleus(DN) of the cerebellum for the correlation with the severity of dementia.Two-tailed t-test,Student-Newman-Keuls test(ANOVA) and linear correlation test were used for statistical analysis.In 30 healthy volunteers,the R2' values of bilateral SN,RN,PU,CN,globus pallidus(GP),TH,and FWM were measured.The correlation with the postmortem iron concentration in normal adults was analyzed in order to establish a formula on the relationship between regional R2' and brain iron concentration.The iron concentration of regions of interest(ROI) in AD patients and controls was calculated by this formula and its correlation with the severity of AD was analyzed.Regional R2' was positively correlated with regional brain iron concentration in normal adults(r=0.977,P0.01).Iron concentrations in bilateral HP,PC,PU,CN,and DN of patients with AD were significantly higher than those of the controls(P0.05);Moreover,the brain iron concentrations,especially in parietal cortex and hippocampus at the early stage of AD,were positively correlated with the severity of patients' cognitive impairment(P0.05).The higher the R2' and iron concentrations were,the more severe the cognitive impairment was.Regional R2' and iron concentration in parietal cortex and hippocampus were positively correlated with the severity of AD patients' cognitive impairment,indicating that it may be used as a biomarker to evaluate the progression of AD.展开更多
The northern Xinjiang region is one of the most significant iron metallogenic provinces in China.Iron deposits are found mainly within three regions:the Altay,western Tianshan,and eastern Tianshan orogenic belts.Previ...The northern Xinjiang region is one of the most significant iron metallogenic provinces in China.Iron deposits are found mainly within three regions:the Altay,western Tianshan,and eastern Tianshan orogenic belts.Previous studies have elaborated on the genesis of Fe deposits in the Altay orogenic belt and western Tianshan.However,the geological characteristics and mineralization history of iron deposits in the eastern Tianshan are still poorly understood.In this paper I describe the geological characteristics of iron deposits in the eastern Tianshan,and discuss their genetic types as well as metallogenic-tectonic settings,Iron deposits are preferentially distributed in central and southern parts of the eastern Tianshan.The known iron deposits in the eastern Tianshan show characteristics of magmatic Fe-Ti-V(e.g.,Weiya and Niumaoquan),sedimentary-metamorphic type(e.g.,Tianhu),and iron skarn(e.g.,Hongyuntan).In addition to the abovementioned iron deposits,many iron deposits in the eastern Tianshan are hosted in submarine volcanic rocks with well-developed skarn mineral assemblages.Their geological characteristics and magnetite compositions suggest that they may belong to distal skarns.SIMS zircon U-Pb analyses suggest that the Fe-Ti oxide ores from Niumaoquan and Weiya deposits were formed at 307.7±1.3 Ma and 242.7±1.9 Ma,respectively.Combined with available isotopic age data,the timing of Fe mineralization in the eastern Tianshan can be divided into four broad intervals:Early Ordovician-Early Silurian(476-438 Ma),Carboniferous(335-303 Ma),Early Permian(295-282 Ma),and Triassic(ca.243 Ma).Each of these episodes corresponds to a period of subduction,post-collision,and intraplate tectonics during the Paleozoic and Mesozoic time.展开更多
In general,the purpose of the mineralization modeling is the advancement of a mineral exploration project and ultimately,the extractive design of a deposit,which is one of the most important stages in mining engineeri...In general,the purpose of the mineralization modeling is the advancement of a mineral exploration project and ultimately,the extractive design of a deposit,which is one of the most important stages in mining engineering.Mineralization modeling is divided into two general categories,superficial and deep modeling.In surface modeling,the aim is finding abnormal locations in terms of mineralization at the study area,which is commonly used in the early stages of exploration as one of the means for locating exploratory boreholes.After drilling in the study area with the aim of identifying mineralization and reserve estimation it is necessary to obtain deep mineralization position and its geometric features,using statistical and modeling methods.Using mathematical,statistical and modeling methods,we can predict the position of iron mineralization in places where drilling is not done and eventually reach a three-dimensional model of the mineral materials underground.As a case study,the deep information about the boreholes of the sheytoor mining area in Yazd province of Iran was investigated.Iron mineralization was modeled as 2D cumulative model and 3D block model,and the results were presented.Finally the geochemical threshold and the anomalous limit of iron element are calculated by concentration-volume(C-V)fractal method in this deposit.Geochemical threshold and the anomalous limit for Fe in this deposit are 24.7%and 34.3%respectively.展开更多
The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analy...The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analysis,field emission scanning electron microscopy,energy dispersive spectrometer,and automatic mineral analysis software.Results identified that 91.69%of ThO2 in the combined samples was mainly distributed in rare earth minerals(bastnaesite,huanghoite,monazite;56.43%abundance in the samples),iron minerals(magnetite,hematite,pyrite;20.97%),niobium minerals(aeschynite;14.29%),and gangue minerals(aegirine,riebeckite,mica,dolomite,apatite,fluorite;4.22%).An unidentified portion(4.09%)of ThO2 may occur in other niobium minerals(niobite,ilmenorutile,pyrochlore).Only a few independent minerals of thorium occur in the iron ore samples.Thorium mainly occurs in rare earth minerals in the form of isomorphic substitution.Analyses of the geochemical characteristics of the major elements indicate that thorium mineralization in the Main Ore Body was related to alkali metasomatism,which provided source material and favorable porosity for hydrothermal mineralization.Trace elements such as Sc,Nb,Zr,and Ta have higher correlation coefficients with thorium,which resulted from being related to the relevant minerals formed during thorium mineralization.In addition,correlation analysis of ThO2 and TFe,and REO and TFe in the six types of iron ore samples showed that ThO2 did not always account for the highest distribution rate in rare earth minerals,and the main occurrence minerals of ThO2 were closely related to iron ore types.展开更多
The metamorphosed sedimentary type of iron deposits(BIF) is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Caraj...The metamorphosed sedimentary type of iron deposits(BIF) is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces(belts), such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type(BIF), magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type(BIF) as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.展开更多
The Cihai iron-cobalt deposit is located in the southern part of the eastern Tianshan iron- polymetallic metallogenic belt. Anomalous native gold and bismuth have been newly identified in Cinan mining section of the C...The Cihai iron-cobalt deposit is located in the southern part of the eastern Tianshan iron- polymetallic metallogenic belt. Anomalous native gold and bismuth have been newly identified in Cinan mining section of the Cihai deposit. Ore formation in the deposit can be divided into three stages based on geological and petrographical observations: (I) skarn, with the main mineral assemblage being garnet-pyroxene-magnetite; (II) retrograde alteration, forming the main iron ores and including massive magnetite, native gold, native bismuth, and cobalt-bearing minerals, with the main mineral assemblage being ilvaite-magnetite-native gold-native bismuth; and (III) quartz-calcite- sulfide assemblage that contains quartz, calcite, pyrrhotite, cobaltite, and safflorite. Native gold mainly coexists with native bismuth, and they are paragenetically related. The temperature of initial skarn formation was higher than 340~C, and then subsequently decreased to -312~C and ~266~C. The temperature of the hydrothermal fluid during the iron ore depositional event was higher than the melting point of native bismuth (271~C), and native bismuth melt scavenged gold in the hydrothermal fluid, forming a Bi-Au melt. As the temperature decreased, the Bi-Au melt was decomposed into native gold and native bismuth. The native gold and native bismuth identified during this study can provide a scientific basis for prospecting and exploration for both gold- and bismuth-bearing deposits in the Cihai mining area. The gold mineralization in Cihai is a part of the Early Permian Cu-Ni-Au-Fe polymetallic ore-forming event, and its discovery has implications for the resource potential of other iron skarn deposits in the eastern Tianshan.展开更多
As a consequence of mining, heavy metal ions can be exposed to the environment hence contaminate ground water and surface water amongst others. The natural polymer chitosan was proved to be an excellent adsorber mater...As a consequence of mining, heavy metal ions can be exposed to the environment hence contaminate ground water and surface water amongst others. The natural polymer chitosan was proved to be an excellent adsorber material for the effective removal of iron and sulfate ions in batch as well as in column experiments. The adsorption behavior of iron ions, as well as sulfate ions was investigated by utilizing chitosan flakes as a natural adsorbent. The removal was studied using adsorbance measurements, SEM and SEM-EDX. The adsorption capacity of chitosan was determined at different times. The received adsorption capacities for iron ions were very promising with a maximum adsorption capacity of 85 mg/g and a rate of separation of 100%. The maximum adsorption capacity obtained for sulfate ions was 188.8 mg/g and a rate of 80%.展开更多
Iron deposited TiO 2 was prepared by photo reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO 2 was deposited with iron, and the optimum n (Fe)/ n (Ti) is 0.25%. TiO...Iron deposited TiO 2 was prepared by photo reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO 2 was deposited with iron, and the optimum n (Fe)/ n (Ti) is 0.25%. TiO 2 and iron deposited TiO 2 are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, the XRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe 3+ and Fe 2+ are present on the surface of 0.5% iron deposited TiO 2, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe 3+ /Fe 2+ couple seems plausible, but Fe 2+ can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO 2, because iron deposited traps photo generated electrons and holes. The fluorescence intensity order of TiO 2 and iron deposited TiO 2, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO 2 and iron deposited TiO 2, from low to high.展开更多
The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, n...The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, nC 17 and nC18, and contain abundant pristane and phytane. These results indicate that iron stromatolite and iron oncolites in orebodies are sedimentary structures of algal origin. Sedimentary iron accumulation mainly results from activity of blue algae. This study provides new valuable evidence for the origin of Xuanlong-type iron deposits.展开更多
Fe(Ⅱ) was deposited into the bottom of the mesopores of highly ordered large caged cubic mesoporous silica by electrodeposition. And the deposited Fe mesoporous silica thin film was treated by 1%---4% HF to remove ...Fe(Ⅱ) was deposited into the bottom of the mesopores of highly ordered large caged cubic mesoporous silica by electrodeposition. And the deposited Fe mesoporous silica thin film was treated by 1%---4% HF to remove the SiO2 template and then calcined. It was found that nanowire bundles, dendritic plates of porous iron oxide, dense parallel backbones of porous iron oxide were obtained at -1.4-- -1.6 V and 0.08--0.1 mol/L electrolyte concentration after calcinations; the dendritic pattern of porous iron oxide film templated by the SBA-16 film was obtained in macrostructure at a higher absolute value of cathode potential(-1.7-- -1.8 V) and a lower electrolyte concentration(0.02-0.05 mol/L), the dendritic pattern of porous iron oxide film could copy the microstructure of SBA-16 film; Fe(II) nanowires grew and formed in one dimension(1D) and two-dimension(2D) electrocrystallization at a potential of-l.6-- -1.7 V and an electrolyte concentration of 0.05 mol/L, and the shape of the ID or 2D crystalline iron oxide nanowires calcined was similar to the original shape of the SBA-16 channels. The desired morphology and size of porous nanocrystal iron oxide can be obtained by adjusting the applied potential value and electrolyte concentration, and all kinds of morphologies of porous nanostructure crystal iron oxide can be prepared.展开更多
Copper was surfaced on the Q235 substrate by shielded metal arc welding (SMAW) and tungsten inert-gas (TIG) arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning ele...Copper was surfaced on the Q235 substrate by shielded metal arc welding (SMAW) and tungsten inert-gas (TIG) arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers' numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.展开更多
The Jalal-Abad iron ore deposit, with a reserve of more than 200 Mt ore, is located in NW of Zarand region, southeastern Iran. The ore deposit occurs in the form of an elongated lens-shaped body incorporated in a fold...The Jalal-Abad iron ore deposit, with a reserve of more than 200 Mt ore, is located in NW of Zarand region, southeastern Iran. The ore deposit occurs in the form of an elongated lens-shaped body incorporated in a folded structure of Rizu volcano-sedimentary unit. Mineralization occurred mainly in siltstones, acidic volcanic rocks and dolomitized limestones. The ore minerals include magnetite, hematite, pyrite, chalcopyrite, goethite, malachite and azurite. Chloritization and silicification are the two most widespread alteration types in the Jalal-Abad area. Cu and Ti are among the associated elements with iron in the ore samples. In comparison, the concentrations of Cu, Ti and REE are relatively low in the samples analyzed. The combined concentrations of Ce, La and Y show that geochemical background values for most areas have been measured. The Pearson correlation coefficient values and the results of cluster and principal component analyses indicate a strong correlation between REE, La, Ce, and Y with Sr in the same geochemical group suggesting a common source for these elements. A close association between Cu and Cl with metasomatic host rock and among Pb, Zn and Ba with carbonate host rocks is observed.展开更多
The Shilu iron ore deposit,located in the western Hainan Province,South China,is one of the most important iron-ore mining districts in China not only for its huge reserves of hematite-rich ores,but also for its poten...The Shilu iron ore deposit,located in the western Hainan Province,South China,is one of the most important iron-ore mining districts in China not only for its huge reserves of hematite-rich ores,but also for its potentially economic significance of associated metals of copper,cobalt,nickel,silver,lead and zinc,and of non-metals of dolomite,quartzite,barite,gypsum and sulfur.展开更多
The Shaytor apatite-rich iron deposit is located in the Kashmar-Kerman tectonic zone in the central of the Iranian plat, which is an important polymetallic belt in Iran. The ore bodies are interbedded with the upper i...The Shaytor apatite-rich iron deposit is located in the Kashmar-Kerman tectonic zone in the central of the Iranian plat, which is an important polymetallic belt in Iran. The ore bodies are interbedded with the upper inferacaamberian calc-alkaline igneous rocks that show well-preserved porphyritic and volcaniclastic textures. The iron ores have massive, disseminated, and brecciated structures. Magnetite from the Shaytor deposit is low in Ti (TiO<sub>2</sub> = up to 0.70 wt.%) and different ore types show similar rare earth element (REE) and trace element-normalized patterns with weak-to-moderate enrichment in light REE and negative Eu anomalies, indicating a common source and genesis. The similar REE patterns for the magnetite and volcanic basaltic host rocks suggest their close genetic linkage and support a magmatic origin for the deposit. The Shaytor deposit shows the typical characteristics of Kiruna-type deposits with regard to the mineral assemblages, ore texture and structure, and the apatite and magnetite geochemistry. We propose that the Kiruna-type Shaytor apatite-rich iron deposit was derived from Fe-P-rich melt through liquid immiscibility and the activity of hydrothermal fluids.展开更多
The Phlaythong large iron deposit in Shampasak of southern Laos,is located in the Kon Tum microblock (Fig.1A),central-southern part of the Indo-China block,and the geographic coordinate of the central mining area is...The Phlaythong large iron deposit in Shampasak of southern Laos,is located in the Kon Tum microblock (Fig.1A),central-southern part of the Indo-China block,and the geographic coordinate of the central mining area is 14°43′04″ N and 106°07′02″ E.展开更多
The precision of Aster data is higher than that of Landsat series of multispectral remote sensing data,which can more accurately reveal the distribution of altered minerals.It plays an important role in prospecting,bu...The precision of Aster data is higher than that of Landsat series of multispectral remote sensing data,which can more accurately reveal the distribution of altered minerals.It plays an important role in prospecting,but it is rarely used in areas with complex terrain and high vegetation coverage.Based on this purpose,this study used Aster remote sensing data,and took Gongchangling iron deposit as a case study.It combined the mineral spectrum theory and the basic geologic data of the study area,using the model of principal component analysis(PCA)and color synthesis to extract abnormal altered minerals.The results show that the distribution of identified anomalies is basically consistent with the existing geological data in this study area,which provides a reliable reference for the mineral resources ex-ploration and delineation of mining areas.展开更多
基金supported by Thailand Science Research and Innovation Fund Chulalongkorn University,Thailand(IND66210014)。
文摘Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of hydrogen sulfide(SOH_(2)S) to elemental sulfur(S) has emerged as a sustainable and environmentally friendly solution.Due to its unique properties,iron oxide has been extensively investigated as a catalyst for SOH_(2)S;however,rapid deactivation has remained a significant drawback.The causes of iron oxide-based catalysts deactivation mechanisms in SOH_(2)S,including sulfur or sulfate deposition,the transformation of iron species,sintering and excessive oxygen vacancy formation,and active site loss,are thoroughly examined in this review.By focusing on the deactivation mechanisms,this review aims to provide valuable insights into enhancing the stability and efficiency of iron-based catalysts for SOH_(2)S.
基金the State Basic Research Program of China(Grant No.G1999043206)
文摘40Ar-39Ar dating of albite from the Meishan and Taocun iron deposits yields plateau ages of 122.90±0.16 Ma and 124.89±0.30 Ma, and isochron ages of 122.60±0.16 Ma and 124.90±0.29 Ma, respectively. Phlogopite from the Zhongshan-Gushan ore field has a plateau age of 126.7±0.17 Ma and an isochron age of 127.21±1.63 Ma. Analysis of regional geodynamic evolution of the middle-lower Yangtze River region suggests that the porphyry iron deposits were formed as a result of large-scale lithosphere delamination and strong sinistral strike-slip movement of the Tancheng Lujiang fault zone. The copper, molybdenum and gold deposit system in the middle-lower Yangtze River region was formed during the stress transition period of the eastern China continent.
基金This paper is financially aided by the National Natural Science Foundation of China (Grant No. 40472055).
文摘Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones (i.e. iron ores) of individual deposits. The assemblage includes magnetite, apatite and actinolite (or diopside). The second type occurs within magnetite-apatite veins in the iron ores. The third type is seen in magnetite-apatite veins and (or) nodules in host rocks (i.e. gabbro-diorite porphyry or gabbro-diorite or pyroxene diorite).The fourth type occurs within apatite-pyrite-quartz veins f'dfing fractures in the Xiangshan Group. Rare earth elements (REE) geochemistry of apatite of the four occurrences in porphyry iron deposits is presented. The REE distribution patterns of apatite are generally similar to those of apatites in the Kiruna-type iron ores, nelsonites. They are enriched in fight REE, with pronounced negative Eu anomalies. The similarity of REE distribution patterns in apatites from various deposits in different locations in the world indicates a common process of formation for various ore types, e.g. immiscibility. Early magmatic apatites contain 3031.48-12080 ×10^-6 REE. Later hydrothermal apatite contains 1958 ×10^-6 REE, indicating that the later hydrothermal ore-forming solution contains lower REE. Although gabbro-diorite porphyry and apatite show similar REE patterns, gabbro-diorite porphyries have no europium anomalies or feeble positive or feeble negative europium anomalies, caused both by reduction environment of mantle source region and by fractionation and crystallization (immiscibility) under a high oxygen fugacity condition. Negative Eu anomalies of apatites were formed possibly due to acquisition of Eu^2+ by earlier diopsite during ore magma cooling. The apatites in the Aoshan and Taishan iron deposits yield a narrow variation range of ^87Sr/^86Sr values from 0.7071 to 0.7073, similar to those of the volcanic and subvolcaulc rocks, indicating that apatites were formed by liquid immiscibility and differentiation of intermediate and basic magmas.
基金financially supported by the Geological Survey Program of China(grants No.K1410 and DD20160346)the National Natural Foundation of China(grants No.41672078 and 41402067)
文摘Long-standing controversy persists over the presence and role of iron-rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron-rich and silica-rich melt inclusions observed in thin-sections are considered as direct evidence for the presence of iron-rich melt, yet unequivocal outcrop-scale evidence of iron-rich melts are still lacking in volcanic rock-hosted iron deposits. Submarine volcanic rock-hosted iron deposits, which are mainly distributed in the western and eastern Tianshan Mountains in Xinjiang, are important resources of iron ores in China, but it remains unclear whether iron-rich melts have played a role in the mineralization of such iron ores. In this study, we observed abundant iron-rich agglomerates in the brecciated andesite lava of the Heijianshan submarine volcanic rock-hosted iron deposit, Eastern Tianshan, China. The iron-rich agglomerates occur as irregular and angular masses filling fractures of the host brecciated andesite lava. They show concentric potassic alteration with silicification or epidotization rims, indicative of their formation after the wall rocks. The iron-rich agglomerates have porphyritic and hyalopilitic textures, and locally display chilled margins in the contact zone with the host rocks. These features cannot be explained by hydrothermal replacement of wall rocks (brecciated andesite lava) which is free of vesicle and amygdale, rather they indicate direct crystallization of the iron-rich agglomerates from iron-rich melts. We propose that the iron-rich agglomerates were formed by open-space filling of volatile-rich iron-rich melt in fractures of the brecciated andesite lava. The iron-rich agglomerates are compositionally similar to the wall-rock brecciated andesite lava, but have much larger variation. Based on mineral assemblages, the iron-rich agglomerates are subdivided into five types, i.e., albite-magnetite type, albite-K-feldspar- magnetite type, K-feldspar-magnetite type, epidote-magnetite type and quartz-magnetite type, representing that products formed at different stages during the evolution of a magmatic-hydrothermal system. The albite-magnetite type represents the earliest crystallization product from a residual iron- rich melt; the albite-K-feldspar-magnetite and K-feldspar-magnetite types show features of magmatic- hydrothermal transition, whereas the epidote-magnetite and quartz-magnetite types represent products of hydrothermal alteration. The occurrence of iron-rich agglomerates provides macroscopic evidence for the presence of iron-rich melts in the mineralization of the Heijianshan iron deposit. It also indicates that iron mineralization of submarine volcanic rock-hosted iron deposits is genetically related to hydrothermal fluids derived from iron-rich melts.
基金supported by grants from the National Natural Science Foundation of China (No. 30870702 and No.30570531)863 Project of China (No. 2006AA02Z4A1)
文摘Brain iron deposition has been proposed to play an important role in the pathophysiology of Alzheimer disease(AD).The aim of this study was to investigate the correlation of brain iron accumulation with the severity of cognitive impairment in patients with AD by using quantitative MR relaxation rate R2' measurements.Fifteen patients with AD,15 age-and sex-matched healthy controls,and 30 healthy volunteers underwent 1.5T MR multi-echo T2 mapping and T2* mapping for the measurement of transverse relaxation rate R2'(R2'=R2*-R2).We statistically analyzed the R2' and iron concentrations of bilateral hippocampus(HP),parietal cortex(PC),frontal white matter(FWM),putamen(PU),caudate nucleus(CN),thalamus(TH),red nucleus(RN),substantia nigra(SN),and dentate nucleus(DN) of the cerebellum for the correlation with the severity of dementia.Two-tailed t-test,Student-Newman-Keuls test(ANOVA) and linear correlation test were used for statistical analysis.In 30 healthy volunteers,the R2' values of bilateral SN,RN,PU,CN,globus pallidus(GP),TH,and FWM were measured.The correlation with the postmortem iron concentration in normal adults was analyzed in order to establish a formula on the relationship between regional R2' and brain iron concentration.The iron concentration of regions of interest(ROI) in AD patients and controls was calculated by this formula and its correlation with the severity of AD was analyzed.Regional R2' was positively correlated with regional brain iron concentration in normal adults(r=0.977,P0.01).Iron concentrations in bilateral HP,PC,PU,CN,and DN of patients with AD were significantly higher than those of the controls(P0.05);Moreover,the brain iron concentrations,especially in parietal cortex and hippocampus at the early stage of AD,were positively correlated with the severity of patients' cognitive impairment(P0.05).The higher the R2' and iron concentrations were,the more severe the cognitive impairment was.Regional R2' and iron concentration in parietal cortex and hippocampus were positively correlated with the severity of AD patients' cognitive impairment,indicating that it may be used as a biomarker to evaluate the progression of AD.
基金This research was jointly supported by the National Key R&D Program of China(Nos.2018YFC0603801 and 2018YFC0604004)National Natural Science Foundation of China(Nos.41903042 and 41530206)+1 种基金China Postdoctoral Science Foundation(Nos.2016LH0003 and 2017M610984)open fund of the Key Lab of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences(No.KLMM20170202).
文摘The northern Xinjiang region is one of the most significant iron metallogenic provinces in China.Iron deposits are found mainly within three regions:the Altay,western Tianshan,and eastern Tianshan orogenic belts.Previous studies have elaborated on the genesis of Fe deposits in the Altay orogenic belt and western Tianshan.However,the geological characteristics and mineralization history of iron deposits in the eastern Tianshan are still poorly understood.In this paper I describe the geological characteristics of iron deposits in the eastern Tianshan,and discuss their genetic types as well as metallogenic-tectonic settings,Iron deposits are preferentially distributed in central and southern parts of the eastern Tianshan.The known iron deposits in the eastern Tianshan show characteristics of magmatic Fe-Ti-V(e.g.,Weiya and Niumaoquan),sedimentary-metamorphic type(e.g.,Tianhu),and iron skarn(e.g.,Hongyuntan).In addition to the abovementioned iron deposits,many iron deposits in the eastern Tianshan are hosted in submarine volcanic rocks with well-developed skarn mineral assemblages.Their geological characteristics and magnetite compositions suggest that they may belong to distal skarns.SIMS zircon U-Pb analyses suggest that the Fe-Ti oxide ores from Niumaoquan and Weiya deposits were formed at 307.7±1.3 Ma and 242.7±1.9 Ma,respectively.Combined with available isotopic age data,the timing of Fe mineralization in the eastern Tianshan can be divided into four broad intervals:Early Ordovician-Early Silurian(476-438 Ma),Carboniferous(335-303 Ma),Early Permian(295-282 Ma),and Triassic(ca.243 Ma).Each of these episodes corresponds to a period of subduction,post-collision,and intraplate tectonics during the Paleozoic and Mesozoic time.
文摘In general,the purpose of the mineralization modeling is the advancement of a mineral exploration project and ultimately,the extractive design of a deposit,which is one of the most important stages in mining engineering.Mineralization modeling is divided into two general categories,superficial and deep modeling.In surface modeling,the aim is finding abnormal locations in terms of mineralization at the study area,which is commonly used in the early stages of exploration as one of the means for locating exploratory boreholes.After drilling in the study area with the aim of identifying mineralization and reserve estimation it is necessary to obtain deep mineralization position and its geometric features,using statistical and modeling methods.Using mathematical,statistical and modeling methods,we can predict the position of iron mineralization in places where drilling is not done and eventually reach a three-dimensional model of the mineral materials underground.As a case study,the deep information about the boreholes of the sheytoor mining area in Yazd province of Iran was investigated.Iron mineralization was modeled as 2D cumulative model and 3D block model,and the results were presented.Finally the geochemical threshold and the anomalous limit of iron element are calculated by concentration-volume(C-V)fractal method in this deposit.Geochemical threshold and the anomalous limit for Fe in this deposit are 24.7%and 34.3%respectively.
基金supported by the National Basic Research Program of China (973 Program) (2012CBA01200)Northern Rare Earth Science and Technology Project (BFXT-2015D-0002) and (2016H1928)
文摘The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analysis,field emission scanning electron microscopy,energy dispersive spectrometer,and automatic mineral analysis software.Results identified that 91.69%of ThO2 in the combined samples was mainly distributed in rare earth minerals(bastnaesite,huanghoite,monazite;56.43%abundance in the samples),iron minerals(magnetite,hematite,pyrite;20.97%),niobium minerals(aeschynite;14.29%),and gangue minerals(aegirine,riebeckite,mica,dolomite,apatite,fluorite;4.22%).An unidentified portion(4.09%)of ThO2 may occur in other niobium minerals(niobite,ilmenorutile,pyrochlore).Only a few independent minerals of thorium occur in the iron ore samples.Thorium mainly occurs in rare earth minerals in the form of isomorphic substitution.Analyses of the geochemical characteristics of the major elements indicate that thorium mineralization in the Main Ore Body was related to alkali metasomatism,which provided source material and favorable porosity for hydrothermal mineralization.Trace elements such as Sc,Nb,Zr,and Ta have higher correlation coefficients with thorium,which resulted from being related to the relevant minerals formed during thorium mineralization.In addition,correlation analysis of ThO2 and TFe,and REO and TFe in the six types of iron ore samples showed that ThO2 did not always account for the highest distribution rate in rare earth minerals,and the main occurrence minerals of ThO2 were closely related to iron ore types.
基金supported by the National Natural Science Foundation of China (grant No. 40773038the Program of High-level Geological Talents (201309)Youth Geological Talents (201112) of the China Geological Survey
文摘The metamorphosed sedimentary type of iron deposits(BIF) is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces(belts), such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type(BIF), magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type(BIF) as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.
基金jointly supported by the National Basic Research Program of China (grant No.2012CB416803)the Ministry of Land and Resources Public Welfare Industry Special Funds for Scientific Research Project (grant No.201211073)NSFC (grant No.41372062)
文摘The Cihai iron-cobalt deposit is located in the southern part of the eastern Tianshan iron- polymetallic metallogenic belt. Anomalous native gold and bismuth have been newly identified in Cinan mining section of the Cihai deposit. Ore formation in the deposit can be divided into three stages based on geological and petrographical observations: (I) skarn, with the main mineral assemblage being garnet-pyroxene-magnetite; (II) retrograde alteration, forming the main iron ores and including massive magnetite, native gold, native bismuth, and cobalt-bearing minerals, with the main mineral assemblage being ilvaite-magnetite-native gold-native bismuth; and (III) quartz-calcite- sulfide assemblage that contains quartz, calcite, pyrrhotite, cobaltite, and safflorite. Native gold mainly coexists with native bismuth, and they are paragenetically related. The temperature of initial skarn formation was higher than 340~C, and then subsequently decreased to -312~C and ~266~C. The temperature of the hydrothermal fluid during the iron ore depositional event was higher than the melting point of native bismuth (271~C), and native bismuth melt scavenged gold in the hydrothermal fluid, forming a Bi-Au melt. As the temperature decreased, the Bi-Au melt was decomposed into native gold and native bismuth. The native gold and native bismuth identified during this study can provide a scientific basis for prospecting and exploration for both gold- and bismuth-bearing deposits in the Cihai mining area. The gold mineralization in Cihai is a part of the Early Permian Cu-Ni-Au-Fe polymetallic ore-forming event, and its discovery has implications for the resource potential of other iron skarn deposits in the eastern Tianshan.
文摘As a consequence of mining, heavy metal ions can be exposed to the environment hence contaminate ground water and surface water amongst others. The natural polymer chitosan was proved to be an excellent adsorber material for the effective removal of iron and sulfate ions in batch as well as in column experiments. The adsorption behavior of iron ions, as well as sulfate ions was investigated by utilizing chitosan flakes as a natural adsorbent. The removal was studied using adsorbance measurements, SEM and SEM-EDX. The adsorption capacity of chitosan was determined at different times. The received adsorption capacities for iron ions were very promising with a maximum adsorption capacity of 85 mg/g and a rate of separation of 100%. The maximum adsorption capacity obtained for sulfate ions was 188.8 mg/g and a rate of 80%.
文摘Iron deposited TiO 2 was prepared by photo reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO 2 was deposited with iron, and the optimum n (Fe)/ n (Ti) is 0.25%. TiO 2 and iron deposited TiO 2 are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, the XRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe 3+ and Fe 2+ are present on the surface of 0.5% iron deposited TiO 2, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe 3+ /Fe 2+ couple seems plausible, but Fe 2+ can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO 2, because iron deposited traps photo generated electrons and holes. The fluorescence intensity order of TiO 2 and iron deposited TiO 2, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO 2 and iron deposited TiO 2, from low to high.
基金This study was supported by China National Natural Science Foundation Grants DI 48970108 and SHENG 39070073
文摘The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, nC 17 and nC18, and contain abundant pristane and phytane. These results indicate that iron stromatolite and iron oncolites in orebodies are sedimentary structures of algal origin. Sedimentary iron accumulation mainly results from activity of blue algae. This study provides new valuable evidence for the origin of Xuanlong-type iron deposits.
基金Supported by the National Natural Science Foundation of China(No.20676027)Postdoctoral Foundation of Heilongjiang Province,China(No.LBH-Q07111)
文摘Fe(Ⅱ) was deposited into the bottom of the mesopores of highly ordered large caged cubic mesoporous silica by electrodeposition. And the deposited Fe mesoporous silica thin film was treated by 1%---4% HF to remove the SiO2 template and then calcined. It was found that nanowire bundles, dendritic plates of porous iron oxide, dense parallel backbones of porous iron oxide were obtained at -1.4-- -1.6 V and 0.08--0.1 mol/L electrolyte concentration after calcinations; the dendritic pattern of porous iron oxide film templated by the SBA-16 film was obtained in macrostructure at a higher absolute value of cathode potential(-1.7-- -1.8 V) and a lower electrolyte concentration(0.02-0.05 mol/L), the dendritic pattern of porous iron oxide film could copy the microstructure of SBA-16 film; Fe(II) nanowires grew and formed in one dimension(1D) and two-dimension(2D) electrocrystallization at a potential of-l.6-- -1.7 V and an electrolyte concentration of 0.05 mol/L, and the shape of the ID or 2D crystalline iron oxide nanowires calcined was similar to the original shape of the SBA-16 channels. The desired morphology and size of porous nanocrystal iron oxide can be obtained by adjusting the applied potential value and electrolyte concentration, and all kinds of morphologies of porous nanostructure crystal iron oxide can be prepared.
文摘Copper was surfaced on the Q235 substrate by shielded metal arc welding (SMAW) and tungsten inert-gas (TIG) arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers' numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.
文摘The Jalal-Abad iron ore deposit, with a reserve of more than 200 Mt ore, is located in NW of Zarand region, southeastern Iran. The ore deposit occurs in the form of an elongated lens-shaped body incorporated in a folded structure of Rizu volcano-sedimentary unit. Mineralization occurred mainly in siltstones, acidic volcanic rocks and dolomitized limestones. The ore minerals include magnetite, hematite, pyrite, chalcopyrite, goethite, malachite and azurite. Chloritization and silicification are the two most widespread alteration types in the Jalal-Abad area. Cu and Ti are among the associated elements with iron in the ore samples. In comparison, the concentrations of Cu, Ti and REE are relatively low in the samples analyzed. The combined concentrations of Ce, La and Y show that geochemical background values for most areas have been measured. The Pearson correlation coefficient values and the results of cluster and principal component analyses indicate a strong correlation between REE, La, Ce, and Y with Sr in the same geochemical group suggesting a common source for these elements. A close association between Cu and Cl with metasomatic host rock and among Pb, Zn and Ba with carbonate host rocks is observed.
文摘The Shilu iron ore deposit,located in the western Hainan Province,South China,is one of the most important iron-ore mining districts in China not only for its huge reserves of hematite-rich ores,but also for its potentially economic significance of associated metals of copper,cobalt,nickel,silver,lead and zinc,and of non-metals of dolomite,quartzite,barite,gypsum and sulfur.
文摘The Shaytor apatite-rich iron deposit is located in the Kashmar-Kerman tectonic zone in the central of the Iranian plat, which is an important polymetallic belt in Iran. The ore bodies are interbedded with the upper inferacaamberian calc-alkaline igneous rocks that show well-preserved porphyritic and volcaniclastic textures. The iron ores have massive, disseminated, and brecciated structures. Magnetite from the Shaytor deposit is low in Ti (TiO<sub>2</sub> = up to 0.70 wt.%) and different ore types show similar rare earth element (REE) and trace element-normalized patterns with weak-to-moderate enrichment in light REE and negative Eu anomalies, indicating a common source and genesis. The similar REE patterns for the magnetite and volcanic basaltic host rocks suggest their close genetic linkage and support a magmatic origin for the deposit. The Shaytor deposit shows the typical characteristics of Kiruna-type deposits with regard to the mineral assemblages, ore texture and structure, and the apatite and magnetite geochemistry. We propose that the Kiruna-type Shaytor apatite-rich iron deposit was derived from Fe-P-rich melt through liquid immiscibility and the activity of hydrothermal fluids.
基金financially supported by the Special fund for Foreign Mineral Resources Risk Exploration (Grant No.Sichuan Financial Investment (2010)331)China Geological Survey (Grant No.12120114012501)
文摘The Phlaythong large iron deposit in Shampasak of southern Laos,is located in the Kon Tum microblock (Fig.1A),central-southern part of the Indo-China block,and the geographic coordinate of the central mining area is 14°43′04″ N and 106°07′02″ E.
基金Supported by projects of Institute of Geology,Chinese Academy of Geological Sciences(No.DD20160121)the National Key Research and Development Program of China(No.2020YFA0714103).
文摘The precision of Aster data is higher than that of Landsat series of multispectral remote sensing data,which can more accurately reveal the distribution of altered minerals.It plays an important role in prospecting,but it is rarely used in areas with complex terrain and high vegetation coverage.Based on this purpose,this study used Aster remote sensing data,and took Gongchangling iron deposit as a case study.It combined the mineral spectrum theory and the basic geologic data of the study area,using the model of principal component analysis(PCA)and color synthesis to extract abnormal altered minerals.The results show that the distribution of identified anomalies is basically consistent with the existing geological data in this study area,which provides a reliable reference for the mineral resources ex-ploration and delineation of mining areas.