Cubic boron nitride (cBN) and orthorhombic boron nitride (oBN) crystals have been prepared in hydrothermal solutions by reacting H3BO3+NaN3+P and H3BO3+NaN3+N2H4 respectively. The experimental results indicated that, ...Cubic boron nitride (cBN) and orthorhombic boron nitride (oBN) crystals have been prepared in hydrothermal solutions by reacting H3BO3+NaN3+P and H3BO3+NaN3+N2H4 respectively. The experimental results indicated that, if the temperature was increased rapidly, both the yield and perfectness of BN crystals became poor. On the contrast, the yield and perfectness of BN crystals can be improved very much by slowly increasing the temperature of the reaction mixture. The results of X-ray powder diffraction (XRD), Fourier transform infrared spectrum (FTIR) and high resolution transmission electron microscopy (HRTEM) proved that the samples were composed of oBN and cBN.展开更多
A novel utilization way of the sludge from wet calcium-based flue gas desulfurization （FGD） processes has been developed in this paper. This study focused on the conversion of the FGD gypsum into α-hemihydrate calc...A novel utilization way of the sludge from wet calcium-based flue gas desulfurization （FGD） processes has been developed in this paper. This study focused on the conversion of the FGD gypsum into α-hemihydrate calcium sulfate by a hydrothermal salt solution method at atmospheric pressure. Experimental study has been carried out in a batch reactor. Qualitative and quantitative analyses were made by DSC/TG thermal analysis, SEM, XRD, metalloscope and chemical analysis. The experimental results showed that the modification of FGD gypsum was controlled by the dissolution and recrystallization mechanisms. With the introduction of FGD gypsum the salt solution was supersaturated, then crystal nucleus of α-hemihydrate calcium sulfate were produced in the solution. With the submicroscopic structure of FGD gypsum crystal changed, the crystal nucleus grew up into α-hemihydrate calcium sulfate crystals. Thus ,the modification of FGD gypsum was fulfilled.展开更多
The Taishang-Shuiwangzhuang gold deposit is located in the southeastern margin of Linglong gold field in the northern part of the Zhaoping Fault metallogenic belt of the Jiaodong gold province-the world’s third-large...The Taishang-Shuiwangzhuang gold deposit is located in the southeastern margin of Linglong gold field in the northern part of the Zhaoping Fault metallogenic belt of the Jiaodong gold province-the world’s third-largest gold metallogenic area.Major prospecting breakthroughs have been made at the depth of 600‒2500 m in recent years,with cumulative proven gold resources exceeding 700 t.Based on a large number of exploration data,the main characteristics of the deposit are described in detail,and the spatial coupling relationship between ore-controlling fault and main orebodies is discussed.The main orebodies occur as regular large veins,exhibiting branching and combination,expansion and contraction,and pinch-out and reoccurrence.They extend in a gentle wave pattern along their strikes and dip directions and generally have a pitch direction of NEE and a plunge direction of NEE.As the ore-controlling fault,the Zhaoping Fault has the characteristics of wave-like fluctuation,with its dip angle presenting three steps of steep-slow transition within the depth range of 2500 m.The gold mineralization enrichment area is mainly distributed in the step parts where the fault plane changes from steeply to gently.The ore-forming age,ore-forming fluid and ore-forming material sources and the genesis of the ore deposit are analyzed based on the research results of ore deposit geochemistry.The ore-forming fluids were H_(2)O-CO_(2)-NaCl-type hydrothermal solutions with a medium-low temperature and medium-low salinity.The H-O isotopic characteristics indicate that the fluids in the early ore-forming stage were possibly formed by degassing of basic magma and that meteoric water gradually entered the ore-forming fluids in the late ore-forming stage.The S and Pb isotopes indicate that the ore-forming materials mainly originate from the lower crust and contain a small quantity of mantle-derived components.The comprehensive analysis shows that the Taishang-shuiwangzhuang gold deposit was a typical“Jiaodong type”gold deposit.The strong crust-mantle interactions,large-scale magmatism,and the material exchange arising from the transformation from the ancient lower crust to the juvenile lower crust during the Early Cretaceous provided abundant fluids and material sources for mineralization.Moreover,the detachment faults formed by the rapid magmatic uplift and the extensional tectonism created favorable temperature and pressure conditions and space for fluid accumulation and gold precipitation and mineralization.展开更多
The dissolubility of hydroxyapatite(HA) in the hydrothermal solution was investigated in Mo-rey-type autoclave over a temperature range of 150 to 350℃ and the pH value range of 5 to 9. It is shown that the dissolubil...The dissolubility of hydroxyapatite(HA) in the hydrothermal solution was investigated in Mo-rey-type autoclave over a temperature range of 150 to 350℃ and the pH value range of 5 to 9. It is shown that the dissolubility of HA is determined as a function of temperature and time under a constant filling ratio of autoclave , and the temperature coefficient for the solubility of HA is positive. The equilibrium time attained in the hydrothermal solution is shortened with the increase of hydroihermal temperature, and the effect of temperature on the solubility is obviously stronger than that of pH value. The solubility data suggest that HA has higher dissolubility in the HA-H2 O system under the hydrothermal condition than that under the normal temperature-pressure.展开更多
A series of CeO2–ZrO2–WO3（CZW）catalysts prepared by a hydrothermal synthesis method showed excellent catalytic activity for selective catalytic reduction（SCR）of NO with NH3 over a wide temperature of 150–550℃....A series of CeO2–ZrO2–WO3（CZW）catalysts prepared by a hydrothermal synthesis method showed excellent catalytic activity for selective catalytic reduction（SCR）of NO with NH3 over a wide temperature of 150–550℃.The effect of hydrothermal treatment of CZW catalysts on SCR activity was investigated in the presence of 10% H2O.The fresh catalyst showed above 90% NOx conversion at 201–459℃,which is applicable to diesel exhaust NOx purification（200–440℃）.The SCR activity results indicated that hydrothermal aging decreased the SCR activity of CZW at low temperatures（below 300℃）,while the activity was notably enhanced at high temperature（above 450℃）.The aged CZW catalyst（hydrothermal aging at 700℃ for 8 hr）showed almost 80% NOx conversion at 229–550℃,while the V2O5–WO3/TiO2 catalyst presented above 80% NOx conversion at 308–370℃.The effect of structural changes,acidity,and redox properties of CZW on the SCR activity was investigated.The results indicated that the excellent hydrothermal stability of CZW was mainly due to the CeO2–ZrO2 solid solution,amorphous WO3 phase and optimal acidity.In addition,the formation of WO3 clusters increased in size as the hydrothermal aging temperature increased,resulting in the collapse of structure,which could further affect the acidity and redox properties.展开更多
The 40Ar-39Ar age method is employed in this work to analyze fluid inclusions of quartz in the ore bodies from the Kuo'erzhenkuola and Bu'erkesidai gold deposits in the Sawur gold belt, northern Xinjiang. The ...The 40Ar-39Ar age method is employed in this work to analyze fluid inclusions of quartz in the ore bodies from the Kuo'erzhenkuola and Bu'erkesidai gold deposits in the Sawur gold belt, northern Xinjiang. The results show that the main mineralization occurred in 332.05±2.02-332.59±0.51 Ma and 335.53±0.32 Ma-336.78±0.50 Ma for the Kuo'erzhenkuola and Bu'erkesidai gold deposits respectively, indicating that the two deposits are formed almost at the same time, and the metallogenic time of the two deposits are close to those of the hosting rocks formed by volcanic activity of the Sawur gold belt. This geochronological study supplies new evidence for determining the timing of gold mineralization, the geneses of gold deposits, and identifies that in the Hercynian period, the Altay area developed a tectonic-magmatic-hydrothermal mineralization of the Early Carboniferous period, except the two known mineralization periods including the tectonic-magmatic-hydrothermal mineralization of the Devonian period and Late Carboniferous- Permian period.展开更多
The NaCl-H_2O binary system is a major component of solutions coexisting with ores. Observation ofsaturated solutions of NaCl-H_2O by using the method of hydrothermal diamond anvil cell (HDAC) is a new approach tothe ...The NaCl-H_2O binary system is a major component of solutions coexisting with ores. Observation ofsaturated solutions of NaCl-H_2O by using the method of hydrothermal diamond anvil cell (HDAC) is a new approach tothe study of ore-forming fluids. The salinities of NaCl-H_2O solutions in experimental observation are in a range of 32-55%. The observed temperature range is 25℃-850℃, and the pressure range 1 atm-10 kb. In this temperature-pressure range, the supercritical single phase, two phases (L,V) close to the critical state and two-phased (L+V) immis-cible region were observed. And for the salinity of 35% the two phase L+V immiscible region of NaCl-H_2O solutionwas observed in a range of 253-720℃. Another temperature range, 400-817℃, was observed for the immiscible two-phased region of 50% salinity solution. In the high-temperature part of the two-phased immiscible region, the phase na-ture is very unstable. A "critical phenomenon" was observed when the heating path was very close to the critical state.It is possible to observe a 'critical phenomenon': an "explosion" occurred almost constantly at the interface between theliquid and vapour and the interface is rather obscure. A continuous transition between phases L and V could be foundin the immiscible L+V phase while heating continuously. Moreover, as the NaCl-H_2O solution was separated into liq-uid and vapour phases, static charges surrounding each vapour bubble could be seen, and these bubbles were attractedtogether by the static charges to form a special solution structure. Besides, critical states of different salinities of NaCl-H_2O were observed in order to study the properties of the fluids occurring in the rocks in the earth interior, the origin ofore-bearing fluids and the significance of supercritical fluid with respect to the ore formation. The comparison of the sa-linity data of the fluid inclusions in the minerals of ore deposits with observations of NaCl-H_2O under HDAC in theconditions of high temperatures and pressures, combined with further thermodynamic analysis of ore-formation condi-tions would explain in depth the factors determining the ore formation.展开更多
Five gold deposits (mineralization) were found in the study area by means of geologi</span><span style="font-family:Verdana;">cal mapping, soil geochemical survey and trough exploration engineeri...Five gold deposits (mineralization) were found in the study area by means of geologi</span><span style="font-family:Verdana;">cal mapping, soil geochemical survey and trough exploration engineering. The</span><span style="font-family:Verdana;"> ore-bearing lithology is mainly metam</span></span><span style="font-family:Verdana;">orphic feldspar sandstone of </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation, and the gold (mineralization) body is controlled by both structural factors </span><span style="font-family:Verdana;">and stratigraphic factors of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation. The genetic</span><span style="font-family:""><span style="font-family:Verdana;"> type is preliminary concluded to be volcanic hyd</span><span style="color:black;font-family:Verdana;">rothermal type, and the metallogenic age is late Variscan. In this paper, by studying the geological characteristics and metallogenic geological conditions of the gold orebody in the area, a regional prospecting model has been established, which is of great significance to better guide the prospecting work of similar gold deposits in the area and the region.展开更多
基金Project supported by the Natural Science Foundation of China (Nos. 50272036 90101016 and 90206042) the Natural Science Foundation of Shan-dong Province and the Foundation of Doctorate Education Discipline by the Ministry of Education of China.
文摘Cubic boron nitride (cBN) and orthorhombic boron nitride (oBN) crystals have been prepared in hydrothermal solutions by reacting H3BO3+NaN3+P and H3BO3+NaN3+N2H4 respectively. The experimental results indicated that, if the temperature was increased rapidly, both the yield and perfectness of BN crystals became poor. On the contrast, the yield and perfectness of BN crystals can be improved very much by slowly increasing the temperature of the reaction mixture. The results of X-ray powder diffraction (XRD), Fourier transform infrared spectrum (FTIR) and high resolution transmission electron microscopy (HRTEM) proved that the samples were composed of oBN and cBN.
文摘A novel utilization way of the sludge from wet calcium-based flue gas desulfurization （FGD） processes has been developed in this paper. This study focused on the conversion of the FGD gypsum into α-hemihydrate calcium sulfate by a hydrothermal salt solution method at atmospheric pressure. Experimental study has been carried out in a batch reactor. Qualitative and quantitative analyses were made by DSC/TG thermal analysis, SEM, XRD, metalloscope and chemical analysis. The experimental results showed that the modification of FGD gypsum was controlled by the dissolution and recrystallization mechanisms. With the introduction of FGD gypsum the salt solution was supersaturated, then crystal nucleus of α-hemihydrate calcium sulfate were produced in the solution. With the submicroscopic structure of FGD gypsum crystal changed, the crystal nucleus grew up into α-hemihydrate calcium sulfate crystals. Thus ,the modification of FGD gypsum was fulfilled.
基金financially supported by the National Key Research and Development Program of China(Grant No.2023YFC2906900)Key Research and Development Program of Shandong Province(Grant No.2023CXGC011001)+2 种基金The Taishan Scholars Talent Project(TSTP 20240847)The Open Project of Technology Innovation Center for Deep Gold Resources Exploration and Mining,Ministry of Natural Resources(Grant No.SDK202211,SDK202214)Science and Technology Project of Shandong Bureau of Geology and Mineral Exploration and Development(Grant No.KY202208)。
文摘The Taishang-Shuiwangzhuang gold deposit is located in the southeastern margin of Linglong gold field in the northern part of the Zhaoping Fault metallogenic belt of the Jiaodong gold province-the world’s third-largest gold metallogenic area.Major prospecting breakthroughs have been made at the depth of 600‒2500 m in recent years,with cumulative proven gold resources exceeding 700 t.Based on a large number of exploration data,the main characteristics of the deposit are described in detail,and the spatial coupling relationship between ore-controlling fault and main orebodies is discussed.The main orebodies occur as regular large veins,exhibiting branching and combination,expansion and contraction,and pinch-out and reoccurrence.They extend in a gentle wave pattern along their strikes and dip directions and generally have a pitch direction of NEE and a plunge direction of NEE.As the ore-controlling fault,the Zhaoping Fault has the characteristics of wave-like fluctuation,with its dip angle presenting three steps of steep-slow transition within the depth range of 2500 m.The gold mineralization enrichment area is mainly distributed in the step parts where the fault plane changes from steeply to gently.The ore-forming age,ore-forming fluid and ore-forming material sources and the genesis of the ore deposit are analyzed based on the research results of ore deposit geochemistry.The ore-forming fluids were H_(2)O-CO_(2)-NaCl-type hydrothermal solutions with a medium-low temperature and medium-low salinity.The H-O isotopic characteristics indicate that the fluids in the early ore-forming stage were possibly formed by degassing of basic magma and that meteoric water gradually entered the ore-forming fluids in the late ore-forming stage.The S and Pb isotopes indicate that the ore-forming materials mainly originate from the lower crust and contain a small quantity of mantle-derived components.The comprehensive analysis shows that the Taishang-shuiwangzhuang gold deposit was a typical“Jiaodong type”gold deposit.The strong crust-mantle interactions,large-scale magmatism,and the material exchange arising from the transformation from the ancient lower crust to the juvenile lower crust during the Early Cretaceous provided abundant fluids and material sources for mineralization.Moreover,the detachment faults formed by the rapid magmatic uplift and the extensional tectonism created favorable temperature and pressure conditions and space for fluid accumulation and gold precipitation and mineralization.
基金Funded by the Nature Science Foundation of Hubei Prov-ince of China.
文摘The dissolubility of hydroxyapatite(HA) in the hydrothermal solution was investigated in Mo-rey-type autoclave over a temperature range of 150 to 350℃ and the pH value range of 5 to 9. It is shown that the dissolubility of HA is determined as a function of temperature and time under a constant filling ratio of autoclave , and the temperature coefficient for the solubility of HA is positive. The equilibrium time attained in the hydrothermal solution is shortened with the increase of hydroihermal temperature, and the effect of temperature on the solubility is obviously stronger than that of pH value. The solubility data suggest that HA has higher dissolubility in the HA-H2 O system under the hydrothermal condition than that under the normal temperature-pressure.
基金supported by the National Natural Science Foundation of China(Nos.U1137603,21307047)the Opening Project of Key Laboratory of Green Catalysis of Sichuan Institutes of High Education(No.LYJ1309)
文摘A series of CeO2–ZrO2–WO3（CZW）catalysts prepared by a hydrothermal synthesis method showed excellent catalytic activity for selective catalytic reduction（SCR）of NO with NH3 over a wide temperature of 150–550℃.The effect of hydrothermal treatment of CZW catalysts on SCR activity was investigated in the presence of 10% H2O.The fresh catalyst showed above 90% NOx conversion at 201–459℃,which is applicable to diesel exhaust NOx purification（200–440℃）.The SCR activity results indicated that hydrothermal aging decreased the SCR activity of CZW at low temperatures（below 300℃）,while the activity was notably enhanced at high temperature（above 450℃）.The aged CZW catalyst（hydrothermal aging at 700℃ for 8 hr）showed almost 80% NOx conversion at 229–550℃,while the V2O5–WO3/TiO2 catalyst presented above 80% NOx conversion at 308–370℃.The effect of structural changes,acidity,and redox properties of CZW on the SCR activity was investigated.The results indicated that the excellent hydrothermal stability of CZW was mainly due to the CeO2–ZrO2 solid solution,amorphous WO3 phase and optimal acidity.In addition,the formation of WO3 clusters increased in size as the hydrothermal aging temperature increased,resulting in the collapse of structure,which could further affect the acidity and redox properties.
基金the Innovative Project of the Chinese Academy of Sciences(Grant No.KZC3-Sw-137) 305 Project ofthe State Science and technology Program of China(GrantNo.2001BA609A-07-08).
文摘The 40Ar-39Ar age method is employed in this work to analyze fluid inclusions of quartz in the ore bodies from the Kuo'erzhenkuola and Bu'erkesidai gold deposits in the Sawur gold belt, northern Xinjiang. The results show that the main mineralization occurred in 332.05±2.02-332.59±0.51 Ma and 335.53±0.32 Ma-336.78±0.50 Ma for the Kuo'erzhenkuola and Bu'erkesidai gold deposits respectively, indicating that the two deposits are formed almost at the same time, and the metallogenic time of the two deposits are close to those of the hosting rocks formed by volcanic activity of the Sawur gold belt. This geochronological study supplies new evidence for determining the timing of gold mineralization, the geneses of gold deposits, and identifies that in the Hercynian period, the Altay area developed a tectonic-magmatic-hydrothermal mineralization of the Early Carboniferous period, except the two known mineralization periods including the tectonic-magmatic-hydrothermal mineralization of the Devonian period and Late Carboniferous- Permian period.
文摘The NaCl-H_2O binary system is a major component of solutions coexisting with ores. Observation ofsaturated solutions of NaCl-H_2O by using the method of hydrothermal diamond anvil cell (HDAC) is a new approach tothe study of ore-forming fluids. The salinities of NaCl-H_2O solutions in experimental observation are in a range of 32-55%. The observed temperature range is 25℃-850℃, and the pressure range 1 atm-10 kb. In this temperature-pressure range, the supercritical single phase, two phases (L,V) close to the critical state and two-phased (L+V) immis-cible region were observed. And for the salinity of 35% the two phase L+V immiscible region of NaCl-H_2O solutionwas observed in a range of 253-720℃. Another temperature range, 400-817℃, was observed for the immiscible two-phased region of 50% salinity solution. In the high-temperature part of the two-phased immiscible region, the phase na-ture is very unstable. A "critical phenomenon" was observed when the heating path was very close to the critical state.It is possible to observe a 'critical phenomenon': an "explosion" occurred almost constantly at the interface between theliquid and vapour and the interface is rather obscure. A continuous transition between phases L and V could be foundin the immiscible L+V phase while heating continuously. Moreover, as the NaCl-H_2O solution was separated into liq-uid and vapour phases, static charges surrounding each vapour bubble could be seen, and these bubbles were attractedtogether by the static charges to form a special solution structure. Besides, critical states of different salinities of NaCl-H_2O were observed in order to study the properties of the fluids occurring in the rocks in the earth interior, the origin ofore-bearing fluids and the significance of supercritical fluid with respect to the ore formation. The comparison of the sa-linity data of the fluid inclusions in the minerals of ore deposits with observations of NaCl-H_2O under HDAC in theconditions of high temperatures and pressures, combined with further thermodynamic analysis of ore-formation condi-tions would explain in depth the factors determining the ore formation.
文摘Five gold deposits (mineralization) were found in the study area by means of geologi</span><span style="font-family:Verdana;">cal mapping, soil geochemical survey and trough exploration engineering. The</span><span style="font-family:Verdana;"> ore-bearing lithology is mainly metam</span></span><span style="font-family:Verdana;">orphic feldspar sandstone of </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation, and the gold (mineralization) body is controlled by both structural factors </span><span style="font-family:Verdana;">and stratigraphic factors of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation. The genetic</span><span style="font-family:""><span style="font-family:Verdana;"> type is preliminary concluded to be volcanic hyd</span><span style="color:black;font-family:Verdana;">rothermal type, and the metallogenic age is late Variscan. In this paper, by studying the geological characteristics and metallogenic geological conditions of the gold orebody in the area, a regional prospecting model has been established, which is of great significance to better guide the prospecting work of similar gold deposits in the area and the region.
