Thermodynamic stability, microvoid distribution and phases transformation of natural pozzolana opal shale(POS) were studied systematically in this work. XRD analysis showed that opal-CT, including microcrystal crist...Thermodynamic stability, microvoid distribution and phases transformation of natural pozzolana opal shale(POS) were studied systematically in this work. XRD analysis showed that opal-CT, including microcrystal cristobalite and tridymite, is a major component of POS. DTA and FT-IR indicated that there were many hydroxyl groups and acid sites on the surface of amorphous SiO2 materials. FE-SEM analysis exhibited amorphous SiO2 particles(opal-A) covering over stacking sequences microcrystal cristobalite and tridymite. Meanwhile, MIP analysis demonstrated that porosity and pore size distribution of POS remained uniform below 600 ℃. Because stable porous microstructure is a key factor in improving photocatalyst activity, POS is suited to preparing highly active supported.展开更多
Fifty-two samples of Miocene pelitic sedimentary rock from outcrops on Medvednica,Moslavacka Gora and Psunj Mts.,and boreholes in the Sava Depression and the Pozega Sub-depression were investigated.These sediments for...Fifty-two samples of Miocene pelitic sedimentary rock from outcrops on Medvednica,Moslavacka Gora and Psunj Mts.,and boreholes in the Sava Depression and the Pozega Sub-depression were investigated.These sediments formed in different marine(with normal and reduced salinity),brackish,and freshwater environments,depending on the development stage of the Pannonian Basin System.Carbonate minerals,clay minerals and quartz are the main constituents of all pelitic sedimentary rocks,except in those from Moslavacka Gora Mt in which carbonate minerals are not present.Feldspars,pyrite,opal-CT,and hematite are present as minor constituents in some rocks.Besides calcite,dependent on the sedimentary environment and diagenetic changes,high-magnesium calcite,aragonite,dolomite and ankerite/Cadolomite are also present.Smectite or illite-smectite is the main clay minerals in the samples.Minor constituents,present in almost all samples,are detrital illite and kaolinite.In some samples chlorite is also present in a low amount.Major elements,trace elements and rare earth elements patterns used in provenance analysis show that all analysed samples have a composition similar to the values of the upper continental crust(UCC).The contents of major and trace elements as well as SiO2/Al2O3,K2O/Al2O3,Na2O/K2O,Eu/Eu*,La/Sc,Th/Sc,La/Co Th/Co,Th/Cr,Ce/Ce* and LREE/HREE ratios,show that the analysed pelitic sedimentary rocks were formed by weathering of different types of mostly acidic(silicic),i.e.felsic rocks.展开更多
Brownshale is a lithology unit in the middle of the Pematang Formation consisting of brown to black shale that is deposited in the lacustrine environment. Brownshale from the results of previous studies stated as the ...Brownshale is a lithology unit in the middle of the Pematang Formation consisting of brown to black shale that is deposited in the lacustrine environment. Brownshale from the results of previous studies stated as the main source rock in the Central Sumatra Basin, which is spread over several troughs, namely Balam, Aman, Rangau, Kiri, and Bengkalis Troughs, where Bengkalis Trough is the most extensive Trough. In the shale hydrocarbon prospecting analysis, Brownshale from previous researchers concluded that it had good prospects, based on several parameters including: TOC values with poor to very good quality. Brownshale formation is a type of kerogene as kerogen type of II/III, brittleness index greater than 0.48, and rock compressive strength below 10,000 Psi. One method in the development phase of shale hydrocarbon is to determine the fracable sweetspot window using drill cuttings and TOC, because there is no core data available. Based on the results of the well log analysis of well BS-03, it is obtained information that the Brownshale formation has a thickness of 1028 feet with intercalation laminated shale/sand section, so the mineral content varies greatly. From the ternary diagram of XRD (bulk analysis) results of drill cuttings of Brownshale formation of well BS-03, it can be seen that mineral distribution of Quartz-Clay-Calcite (Q-C-C) is spread between zone 1 to zone 3, namely: Dominant Quartz - Minor Clay & Carbonate (Zone 1: Brittle Quartz Rich), Dominant Carbonate - Quartz & Minor Clay (Zone 2: Brittle Carbonate Rich), and Quartz & Carbonate Balance - Clay minor (Zone 3: Ductile, hard to frac). This shows that not all Brownshale formation intervals are easy to frac (high fracability). From the XRD result, percentage of mineral content (bulk analysis) of Brownshale drill cuttings, there is an interesting phenomenon, <i>i.e. </i> the presence of sillimanite and kaliophilite minerals significantly starting at a depth of 10,780 ft and below, where both minerals have tenacity: brittle, and also from the results of the MBT analysis seen an interesting phenomenon, <i>i.e. </i> at a depth interval of about 10,780 ft the value of CEC drops below 3 meq/100 grams, and can be categorized as the brittle shale. Referring to the presence of sillimanite and kaliophilite minerals, as well as low MBT values, then at intervals of 10,780 ft below, it can be seen that at the bottom of the depth interval as a fracable sweetspot window, and at the upper depth interval of the Brownshale formation, it is believed to be a fracture barrier.展开更多
With the development of arsenic removal technologies, biological method and sulfide method have been applied in industrial fields, other methods have also been applied in arsenic-containing copper flotation, including...With the development of arsenic removal technologies, biological method and sulfide method have been applied in industrial fields, other methods have also been applied in arsenic-containing copper flotation, including coagulation process, ion exchange method, direct precipitation method and so on. In the paper, a short review on the progress of arsenic removal technologies of copper flotation during the last decade is presented, and the importance and the trend of arsenic removal are discussed. The existing and possible strategies of improving copper recovery in porphyry copper ores and rejection of penalty elements such as Tennantite and Enargite in copper flotation concentrates are also presented.展开更多
Dredged soil and phosphogypsum are frequently regarded as wasted materials,which require further treatment to control their environmental impact.Hence,phosphogypsum is proposed as a binder to stabilize dredged soil,ai...Dredged soil and phosphogypsum are frequently regarded as wasted materials,which require further treatment to control their environmental impact.Hence,phosphogypsum is proposed as a binder to stabilize dredged soil,aiming at efficiently reducing and reusing these waste materials.In this study,the engineering properties of cement-phosphogypsum stabilized dredged soils were investigated through a series of unconfined compression tests,and the effects of plasticity index of original soils on the strength improvement were identified.Then,the microstructure test and mineralogical test were performed to understand the mechanism of physical role of original soils in strength improvement.The results revealed that the unconfined compressive strength significantly decreased with the increase in plasticity index at the same binder content.The essential factor for strength improvement was found to be the formation of cementitious materials identified as calcium silicate hydrate(CSH),calcium aluminate hydrate(CAH),and ettringite(Aft).The normalized integrated intensity of cementitious materials(CSH+CAH+Aft)by pore volume decreased with the increase in plasticity index.Consequently,the density of cementitious materials filling the soil pores controlled the effectiveness of strength improvement.More cementitious materials per pore volume were observed for the original soils with lower values of plasticity index.That is,the higher strength of stabilized soils with lower values of plasticity index was attributed to a packed structure forming by integrated fabric through denser cementitious components.It can be anticipated from the above findings that the effectiveness of stabilization treatment will significantly reduce with the increase in plasticity of origin soil.展开更多
Mushroom shaped rocks are not uncommon in nature, but their origin is often misunderstood because they can be formed by different natural forces. A huge mushroom stone in a stream valley of the Xiqiao Mountain of Guan...Mushroom shaped rocks are not uncommon in nature, but their origin is often misunderstood because they can be formed by different natural forces. A huge mushroom stone in a stream valley of the Xiqiao Mountain of Guangdong,China is widely believed to be formed through the way of stream water erosion. However, the result of the simulation performed with Flow-3 D in this study indicates that the mushroom shape of the rock could not have been sculpted by the flowing water erosion because the simulation result contradicts that of the field investigations:(1) the sediment brought by upstream flowing water tends to be deposited on the leeward side of the flowing water preventing the rock on this side form being eroded, but the narrowest part of the rock bottom is exactly located on this side of the rock and(2) the stream flow should erode the bed sediment and produce high abrasion on the rock surface on the upstream and lateral sides of the rock,respectively, but no abrasion marks are found on the same sides of the rock. Subsequent geological analyses in this study provide evidence that the narrow bottom of the mushroom stone was resulted from chemical and physical weathering happening within the sediment that used to deposit on the lee side of the stone.展开更多
Gypsum is widely distributed in Tunisia occurring in the formation of Triassic age. The gypsum deposit of Mellegue is the alabastine type with a little of the porphyroblast type and contains traces of clay minerals an...Gypsum is widely distributed in Tunisia occurring in the formation of Triassic age. The gypsum deposit of Mellegue is the alabastine type with a little of the porphyroblast type and contains traces of clay minerals and calcite. It is a moderately strong rock in terms of its unconfined compressive strength of 16 Mpa and tensile strength of 3.35 Mpa. Triaxial testing values indicated an apparent cohesion of 10 Mpa and an angle of friction of 26°. The gypsum studied had a percentage of SO<sub>3</sub> of 41.71% and a percentage of CaO of 32.9%. All the samples had low densities according to the International Association of Engineering Geology (IAEG) classification and exhibited a moderate porosity whether effective or absolute. The gypsum proved to be moderately strong when tested in unconfined compression and tensile strength. Thermal analysis indicated a total weight loss of 20.27% and the whiteness index about 90%. This proved a high degree of whiteness. The time of setting can be considered short and medium, which is quite favorable for industrial application compared with other gypsum deposits currently operated.展开更多
The sodium roasted-acid leaching tailing(SRALT)of vanadium slag with a certain amount of vanadium exhibits potential environmental risk.To investigate the leaching behavior of vanadium from the SRALT,neutral batch lea...The sodium roasted-acid leaching tailing(SRALT)of vanadium slag with a certain amount of vanadium exhibits potential environmental risk.To investigate the leaching behavior of vanadium from the SRALT,neutral batch leaching tests were performed.The evolution of vanadium concentration,pH,redox potential(Eh),dissolved oxygen,and conductivity as a function of time was measured.Pourbaix diagrams of V–H2O system with different vanadium concentrations were obtained to identify the ionic speciation of vanadium in leachate.X-ray diffraction,X-ray photoelectron spectroscopy,field emission-scanning electron microscopy,and thermogravimetry–differential scanning calorimetry analysis were conducted to investigate the mineralogical evolution of the SRALT during the leaching process.It was found that the major minerals of the original SRALT are titanomagnetite,spinel,olivine,and augite.The valence states of V existing in the original SRALT are V^(3+)and V^(5+).The pH and Eh values of the obtained leachates are 10.00–10.58 and(−43)–(+67)mV,respectively.In this pH and Eh region,the released vanadium is mainly present as HVO_(4)^(2−).The FeOOH and CaCO_(3)would form during the leaching process.The HVO_(4)^(2−)would be mainly adsorbed by the FeOOH and slightly incorporated into the CaCO_(3),resulting in the decline in the vanadium concentration.The vanadium concentration above 27 mg L^(−1)and the dissolved oxygen value below 5.0 mg L^(−1)can be obtained after a short leaching period.As a V(V)-releasing and oxygen-depleting substance,the leaching toxicity of the SRALT should not be ignored.展开更多
Awide range of pulmonary pathology is attributed to aluminum dust exposure, including interstitial fibrosis^1-5 desquamative interstitial pneumonia^6 and pulmonary alveolar proteinosis^7 To our knowledge, granulomatou...Awide range of pulmonary pathology is attributed to aluminum dust exposure, including interstitial fibrosis^1-5 desquamative interstitial pneumonia^6 and pulmonary alveolar proteinosis^7 To our knowledge, granulomatous lung disease induced by aluminum dust is rare, only two cases were reported in literatures^8.9 We had the opportunity to make a diagnosis of pulmonary sarcoid-like granulomatosis in a patient exposed to aluminum dust. Herein, we report the clinical history, radiographic and histopathological findings in this patient, and the detailed mineralogical analyses performed on lung tissue obtained by open lung biopsy.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51278086,51578108)Special Fund for Scientific Research in the Public Interest by Ministry of Water Resource of the People’s Republic of China(No.201501003)
文摘Thermodynamic stability, microvoid distribution and phases transformation of natural pozzolana opal shale(POS) were studied systematically in this work. XRD analysis showed that opal-CT, including microcrystal cristobalite and tridymite, is a major component of POS. DTA and FT-IR indicated that there were many hydroxyl groups and acid sites on the surface of amorphous SiO2 materials. FE-SEM analysis exhibited amorphous SiO2 particles(opal-A) covering over stacking sequences microcrystal cristobalite and tridymite. Meanwhile, MIP analysis demonstrated that porosity and pore size distribution of POS remained uniform below 600 ℃. Because stable porous microstructure is a key factor in improving photocatalyst activity, POS is suited to preparing highly active supported.
基金funded by the Ministry of Science,Education and Sports,Republic of Croatia,Projects:Basic Geological Map of the Republic of Croatia,1:50,000(181-1811096-1093)the Map of Mineral and Energy Resources of the Republic of Croatia(1811811096-1104)+1 种基金Metamorphic and Magmatic Events in the Panonnian Basin Basement and Dinarides(119-1191155-1156)Evolutionary Changes of the Dinarides from Subduction to Modern Adriatic Beaches(119-1191155-1159)
文摘Fifty-two samples of Miocene pelitic sedimentary rock from outcrops on Medvednica,Moslavacka Gora and Psunj Mts.,and boreholes in the Sava Depression and the Pozega Sub-depression were investigated.These sediments formed in different marine(with normal and reduced salinity),brackish,and freshwater environments,depending on the development stage of the Pannonian Basin System.Carbonate minerals,clay minerals and quartz are the main constituents of all pelitic sedimentary rocks,except in those from Moslavacka Gora Mt in which carbonate minerals are not present.Feldspars,pyrite,opal-CT,and hematite are present as minor constituents in some rocks.Besides calcite,dependent on the sedimentary environment and diagenetic changes,high-magnesium calcite,aragonite,dolomite and ankerite/Cadolomite are also present.Smectite or illite-smectite is the main clay minerals in the samples.Minor constituents,present in almost all samples,are detrital illite and kaolinite.In some samples chlorite is also present in a low amount.Major elements,trace elements and rare earth elements patterns used in provenance analysis show that all analysed samples have a composition similar to the values of the upper continental crust(UCC).The contents of major and trace elements as well as SiO2/Al2O3,K2O/Al2O3,Na2O/K2O,Eu/Eu*,La/Sc,Th/Sc,La/Co Th/Co,Th/Cr,Ce/Ce* and LREE/HREE ratios,show that the analysed pelitic sedimentary rocks were formed by weathering of different types of mostly acidic(silicic),i.e.felsic rocks.
文摘Brownshale is a lithology unit in the middle of the Pematang Formation consisting of brown to black shale that is deposited in the lacustrine environment. Brownshale from the results of previous studies stated as the main source rock in the Central Sumatra Basin, which is spread over several troughs, namely Balam, Aman, Rangau, Kiri, and Bengkalis Troughs, where Bengkalis Trough is the most extensive Trough. In the shale hydrocarbon prospecting analysis, Brownshale from previous researchers concluded that it had good prospects, based on several parameters including: TOC values with poor to very good quality. Brownshale formation is a type of kerogene as kerogen type of II/III, brittleness index greater than 0.48, and rock compressive strength below 10,000 Psi. One method in the development phase of shale hydrocarbon is to determine the fracable sweetspot window using drill cuttings and TOC, because there is no core data available. Based on the results of the well log analysis of well BS-03, it is obtained information that the Brownshale formation has a thickness of 1028 feet with intercalation laminated shale/sand section, so the mineral content varies greatly. From the ternary diagram of XRD (bulk analysis) results of drill cuttings of Brownshale formation of well BS-03, it can be seen that mineral distribution of Quartz-Clay-Calcite (Q-C-C) is spread between zone 1 to zone 3, namely: Dominant Quartz - Minor Clay & Carbonate (Zone 1: Brittle Quartz Rich), Dominant Carbonate - Quartz & Minor Clay (Zone 2: Brittle Carbonate Rich), and Quartz & Carbonate Balance - Clay minor (Zone 3: Ductile, hard to frac). This shows that not all Brownshale formation intervals are easy to frac (high fracability). From the XRD result, percentage of mineral content (bulk analysis) of Brownshale drill cuttings, there is an interesting phenomenon, <i>i.e. </i> the presence of sillimanite and kaliophilite minerals significantly starting at a depth of 10,780 ft and below, where both minerals have tenacity: brittle, and also from the results of the MBT analysis seen an interesting phenomenon, <i>i.e. </i> at a depth interval of about 10,780 ft the value of CEC drops below 3 meq/100 grams, and can be categorized as the brittle shale. Referring to the presence of sillimanite and kaliophilite minerals, as well as low MBT values, then at intervals of 10,780 ft below, it can be seen that at the bottom of the depth interval as a fracable sweetspot window, and at the upper depth interval of the Brownshale formation, it is believed to be a fracture barrier.
文摘With the development of arsenic removal technologies, biological method and sulfide method have been applied in industrial fields, other methods have also been applied in arsenic-containing copper flotation, including coagulation process, ion exchange method, direct precipitation method and so on. In the paper, a short review on the progress of arsenic removal technologies of copper flotation during the last decade is presented, and the importance and the trend of arsenic removal are discussed. The existing and possible strategies of improving copper recovery in porphyry copper ores and rejection of penalty elements such as Tennantite and Enargite in copper flotation concentrates are also presented.
基金supported by the National Natural Science Foundation of China(Grant Nos.52178328 and 52178361)Partial financial support from the Open-end Research Fund of State Key Laboratory for Geomechanics and Deep Underground Engineering(Grant No.SKLGDUEK2114)。
文摘Dredged soil and phosphogypsum are frequently regarded as wasted materials,which require further treatment to control their environmental impact.Hence,phosphogypsum is proposed as a binder to stabilize dredged soil,aiming at efficiently reducing and reusing these waste materials.In this study,the engineering properties of cement-phosphogypsum stabilized dredged soils were investigated through a series of unconfined compression tests,and the effects of plasticity index of original soils on the strength improvement were identified.Then,the microstructure test and mineralogical test were performed to understand the mechanism of physical role of original soils in strength improvement.The results revealed that the unconfined compressive strength significantly decreased with the increase in plasticity index at the same binder content.The essential factor for strength improvement was found to be the formation of cementitious materials identified as calcium silicate hydrate(CSH),calcium aluminate hydrate(CAH),and ettringite(Aft).The normalized integrated intensity of cementitious materials(CSH+CAH+Aft)by pore volume decreased with the increase in plasticity index.Consequently,the density of cementitious materials filling the soil pores controlled the effectiveness of strength improvement.More cementitious materials per pore volume were observed for the original soils with lower values of plasticity index.That is,the higher strength of stabilized soils with lower values of plasticity index was attributed to a packed structure forming by integrated fabric through denser cementitious components.It can be anticipated from the above findings that the effectiveness of stabilization treatment will significantly reduce with the increase in plasticity of origin soil.
基金funded by the Natural Science Foundation of China(Grants No.41571002,42171007 and 42171005)Natural Science Foundation of Guangdong,China(2015A030313385)Foundation for the Young Creative Talent Foundation in Higher Education of Guangdong,China(2014KQNCX193)。
文摘Mushroom shaped rocks are not uncommon in nature, but their origin is often misunderstood because they can be formed by different natural forces. A huge mushroom stone in a stream valley of the Xiqiao Mountain of Guangdong,China is widely believed to be formed through the way of stream water erosion. However, the result of the simulation performed with Flow-3 D in this study indicates that the mushroom shape of the rock could not have been sculpted by the flowing water erosion because the simulation result contradicts that of the field investigations:(1) the sediment brought by upstream flowing water tends to be deposited on the leeward side of the flowing water preventing the rock on this side form being eroded, but the narrowest part of the rock bottom is exactly located on this side of the rock and(2) the stream flow should erode the bed sediment and produce high abrasion on the rock surface on the upstream and lateral sides of the rock,respectively, but no abrasion marks are found on the same sides of the rock. Subsequent geological analyses in this study provide evidence that the narrow bottom of the mushroom stone was resulted from chemical and physical weathering happening within the sediment that used to deposit on the lee side of the stone.
文摘Gypsum is widely distributed in Tunisia occurring in the formation of Triassic age. The gypsum deposit of Mellegue is the alabastine type with a little of the porphyroblast type and contains traces of clay minerals and calcite. It is a moderately strong rock in terms of its unconfined compressive strength of 16 Mpa and tensile strength of 3.35 Mpa. Triaxial testing values indicated an apparent cohesion of 10 Mpa and an angle of friction of 26°. The gypsum studied had a percentage of SO<sub>3</sub> of 41.71% and a percentage of CaO of 32.9%. All the samples had low densities according to the International Association of Engineering Geology (IAEG) classification and exhibited a moderate porosity whether effective or absolute. The gypsum proved to be moderately strong when tested in unconfined compression and tensile strength. Thermal analysis indicated a total weight loss of 20.27% and the whiteness index about 90%. This proved a high degree of whiteness. The time of setting can be considered short and medium, which is quite favorable for industrial application compared with other gypsum deposits currently operated.
基金supported by the Natural Science Foundation of Hebei Province(Nos.E2020209195,E2021209043,E2020209043),National Natural Science Foundation of China(No.51574108),Tangshan Municipal Project of Science and Technology(No.19150201E)Science and Technology Project of Hebei Education Department(Nos.BJ2020022,BJ2021034).
文摘The sodium roasted-acid leaching tailing(SRALT)of vanadium slag with a certain amount of vanadium exhibits potential environmental risk.To investigate the leaching behavior of vanadium from the SRALT,neutral batch leaching tests were performed.The evolution of vanadium concentration,pH,redox potential(Eh),dissolved oxygen,and conductivity as a function of time was measured.Pourbaix diagrams of V–H2O system with different vanadium concentrations were obtained to identify the ionic speciation of vanadium in leachate.X-ray diffraction,X-ray photoelectron spectroscopy,field emission-scanning electron microscopy,and thermogravimetry–differential scanning calorimetry analysis were conducted to investigate the mineralogical evolution of the SRALT during the leaching process.It was found that the major minerals of the original SRALT are titanomagnetite,spinel,olivine,and augite.The valence states of V existing in the original SRALT are V^(3+)and V^(5+).The pH and Eh values of the obtained leachates are 10.00–10.58 and(−43)–(+67)mV,respectively.In this pH and Eh region,the released vanadium is mainly present as HVO_(4)^(2−).The FeOOH and CaCO_(3)would form during the leaching process.The HVO_(4)^(2−)would be mainly adsorbed by the FeOOH and slightly incorporated into the CaCO_(3),resulting in the decline in the vanadium concentration.The vanadium concentration above 27 mg L^(−1)and the dissolved oxygen value below 5.0 mg L^(−1)can be obtained after a short leaching period.As a V(V)-releasing and oxygen-depleting substance,the leaching toxicity of the SRALT should not be ignored.
文摘Awide range of pulmonary pathology is attributed to aluminum dust exposure, including interstitial fibrosis^1-5 desquamative interstitial pneumonia^6 and pulmonary alveolar proteinosis^7 To our knowledge, granulomatous lung disease induced by aluminum dust is rare, only two cases were reported in literatures^8.9 We had the opportunity to make a diagnosis of pulmonary sarcoid-like granulomatosis in a patient exposed to aluminum dust. Herein, we report the clinical history, radiographic and histopathological findings in this patient, and the detailed mineralogical analyses performed on lung tissue obtained by open lung biopsy.