The tabular beryl found in Huya Country, Sichuan Province is a rare and special member among beryls. Chemical analysis reveals that the beryl is a new type of Cs-rich Na-Li beryl, and the content of alkalis （Li20, Na...The tabular beryl found in Huya Country, Sichuan Province is a rare and special member among beryls. Chemical analysis reveals that the beryl is a new type of Cs-rich Na-Li beryl, and the content of alkalis （Li20, Na2O, K2O, Rb2O, Cs2O） is up to 2.41%. The CCD system on the SMART APEX four circle single crystal diffractometer was used in this experiment to determine the structure of the sample accurately. The beryl belongs to the hexagonal system; its space group is P6/mcc. The dimensions of the unit cell are as follows： a = 0.91961（3） nm, c = 0.91969（7） nm, c/a = 1.0000, V= 0.67357 nm3, 7 = 120°, α= 90°, β = 90°. The accurate atomic coordinates of alkali metal ions and other crystallographic parameters are also obtained： Z = 2, the calculated density D = 2.754 g/cm^3 and final R （ I 〉 2 σ （/3）= 0.046 for 5597 reflections. The crystal structure was described by coordination polyhedron. Based on the data gained, a three-dimensional graph of the crystal structure of tabular beryl was made with the ATOMS 6.0 software. The refinement of crystal structure indicates that there are two main reasons for the cause of the tabular configuration： （1） The substitution of Be by Li into the tetrahedral framework weakened the stacked six-sided rings [Si6O18]^12- of the tetrahedral Si; （2） Alkalis （mainly Na and Cs） are too large to substitute in four-fold or six-fold coordination within the structure and are accommodated in the vacant channel. The accommodation of these alkalis strengthened the structure of six-sided rings of the tetrahedral Si. And other alkali metal ions and free volatile molecules such as H2O and CO2 occupy variable positions in the channel. The equation of the electrovalence is Li＋＋Na＋→Be^2＋. According to structural and compositional differences, the monoclinic crystal of tabular beryl is considered to be a new member of the beryl group. Chemical constraints of the environment, namely, the bulk-rock chemistry and the fluid-phase composition and physical-chemical conditions during the growth of the mineral may account for these occurrences of rare elements. In addition, that Li and Be have appro^mate physical parameters is also the key factor for the substitution. The direction of the mineralized hydrothermal liquid and the special occurrence conditions of the beryl such as the pH, temperature and pressure are also considered to be the main causes of the configuration of the tabular beryl.展开更多
Effects of multivalent metallic cations, such as Ca2+ and Fe3+, on the flotation of spodumene and beryl were studied. The results show that Fe3+ and Ca2+ exhibit efficient activation on the flotation of spodumene and ...Effects of multivalent metallic cations, such as Ca2+ and Fe3+, on the flotation of spodumene and beryl were studied. The results show that Fe3+ and Ca2+ exhibit efficient activation on the flotation of spodumene and beryl. The ac- tivation of Fe3+ happens quite well within a pH range of 6-9 while the concentration of Fe3+ is 35 mg/L. Efficient acti- vation of Ca2+ takes place over at a pH over 11.6 at a concentration of 140 mg/L. The zeta potential of beryl and spo- dumene shifts slightly to positive values when activated by Ca2+, but markedly by Fe3+. New stretching frequencies of 1594.24 cm-1 and 1587.13 cm-1 have been found in the FTIR spectra of the two minerals after their interaction with Fe3+ and the collector. These new stretching frequencies are the asymmetric stretching frequencies of COO-(carboxyl anion), so thecollector may be chemically absorbed on the surface of Fe3+-activated beryl and spodumene.展开更多
Beryllium aluminum cyclosilicate, an ore of beryllium was reinforced in Aluminum matrix to fabricate Al-beryl composites using powder metallurgy. Effect of the content of beryllium aluminum cyclosilicate on microstruc...Beryllium aluminum cyclosilicate, an ore of beryllium was reinforced in Aluminum matrix to fabricate Al-beryl composites using powder metallurgy. Effect of the content of beryllium aluminum cyclosilicate on microstructural hardness and thermal expansion was studied. The coefficient of thermal expansion of Al-beryl composite was measured in the temperature range between 50oC to 360oC using dilatometer and was theoretically studied using thermo-elastic models, and these models were used to explain abnormalities observed experimentally. The hardness of Al-beryl metal matrix composites increased with the increase in beryl percentage. Vacuum sintering of Al-beryl metal matrix composites at 600oC inhibited excellent bonding between the matrix and the particulate increasing the strength of the composite. The result shows the CTE significantly increased with increasing temperature but decreased with increasing reinforcement. At higher temperatures, CTE of Al-beryl metal matrix composites with 5 wt%, 10 wt% and 15 wt% of beryllium aluminum cyclosilicate was 21 ppm/K, 18.2 ppm/K, and 16.8 ppm/K. The CTE values were found to be comparable with theoretical results. The turner model showed conformance with experimental results, was well suited to the experimental results.展开更多
The Beryl Embayment is situated at the south end of the North Viking Graben in the North Sea. Three sets of normal faults, with N-S, NW-SE and NE-SW orientations, have been recognized in the Beryl Embayment. High-reso...The Beryl Embayment is situated at the south end of the North Viking Graben in the North Sea. Three sets of normal faults, with N-S, NW-SE and NE-SW orientations, have been recognized in the Beryl Embayment. High-resolution subsidence analysis of 73 wells, combined with some seismic data, has been used to document Middle to Late Jurassic subsidence patterns in this area. The high temporal resolution achieved （1 to 2 million years per data point） has also allowed an assessment to be made of temporal evolution of faults with different orientations, and a study made of how and when the East Shetland Fault was linked and controlled sedimentary facies distributions. The results indicate that the East Shetland Fault can be divided into northern and southern parts which were linked together during the Early-Mid Oxfordian. The Mid-Late Jurassic syn-rift phase can be divided into four stages： minor active extension stage during the Bathonian-Middle Callovian, early syn-rotational stage during the Late Callovian-Early-Mid Oxfordian, syn-rotational climax stage during the Late Oxfordian-Early Volgian, and late syn-rotational stage during the Mid-Late Volgian. The results also show that there was a sequential variation of extension direction of active normal faults with different orientations, with an overall shift in the dominant orientation of active normal faults from N-S in the Bathonian-Middle Oxfordian, through NNW-SSE in the Late Oxfordian-Early Volgian （≈N30°E）, to NW-SE （≈N45°E） in the Mid-Late Volgian.展开更多
Since most beryls are characterized by prismatic configuration and originate from pegmatite and granite,platy beryl is considered especially rare.Therefore,the aims of this study are to determine the spectrographic an...Since most beryls are characterized by prismatic configuration and originate from pegmatite and granite,platy beryl is considered especially rare.Therefore,the aims of this study are to determine the spectrographic and chemical characteristics of the platy beryl;examine the relationships between the spectrographic parameters and alkali elements and discuss the possible genesis of its platy habit based on those results.To accomplish this,ICP-MS,ICP-AES,XRF,XRD and IR analyses were all performed on platy beryls from the Xuebaoding hydrothermal W-Sn-Be deposit.The results revealed that the samples represent alkali-rich beryl which could therefore be named as sodic-lithian and cesium-rich beryl and was showed to be a tetrahedron-substituted beryl.展开更多
Beryl is the commercial source of beryllium and several varieties of it are valued as a gemstone.To contribute to understanding the mechanism of beryl formation,we carried out detailed geological,petrographical,and ge...Beryl is the commercial source of beryllium and several varieties of it are valued as a gemstone.To contribute to understanding the mechanism of beryl formation,we carried out detailed geological,petrographical,and geochemical investigations on beryl mineralization occurrences in the Zabara-Wadi El Gemal(Z-WG)region.This region is an NW-SE trending tract that includes six berylhosting areas.The green gem variety of beryl(emerald)is restricted to phlogopite schist,pegmatite,and quartz veins.Prismatic hexagonal emerald crystals are well-developed in phlogopite schist and pegmatite.The gem variety emerald examined is sodic and Cr-dominant.It contains high concentrations of chromophore transition elements ordering Cr(up to 1511 ppm)>V(up to 242 ppm)>Sc(up to 245 ppm),giving rise to its vivid green color,refl ecting mafic-ultramafic source contribution.Among the investigated emeralds,the Sikait area contains the highest BeO(av.10.76wt.%)concentration.The compositional variability of emeralds is most likely attributed to the contribution from the host rocks.This is revealed by the examined emerald mineralization,for instance;the Abu Rusheid area(one of the best areas exposing rare metal-bearing granitoids)possesses the highest average of trace and REEs concentrations.In contrast,Um Kabu emerald has the highest contents of Co(av.20 ppm),Ni(av.299 ppm),MgO(av.8.2wt.%),Fe_(2)O_(3)(av.3.12wt.%),and CaO(avg.3.4wt.%)relative to other areas,which may be linked to contribution of ultramafic rocks exposed there.The proposed mechanism we suggest for emerald genesis is metasomatic interaction between felsic intrusions,that are enriched with K,Na,Be,Li,and B,with mafic-ultramafic rocks that are enriched in Cr,V,Mg,Fe,and Ca.This interaction is marked by the formation of phlogopite schist,the growth of emerald crystals,and desilicated pegmatite.展开更多
Beryl-Al6061 alloy composites having 2-12 wt% of beryl particles were fabricated by liquid metallurgy (stir cast) method. The tensile and wear properties of beryl-Al6061 composites have been evaluated and compared wit...Beryl-Al6061 alloy composites having 2-12 wt% of beryl particles were fabricated by liquid metallurgy (stir cast) method. The tensile and wear properties of beryl-Al6061 composites have been evaluated and compared with its base alloy. The results revealed that the Al6061-10 wt% of beryl composites shows an improvement of 15.38% in tensile strength and specific wear rate decreases by 8.9% at normal load of 9.81N when compared to matrix i.e. base alloy. Significant improvement in tensile properties and hardness are noticed as the wt% of the beryl particles increases. The microstructures of the composites were studied to know the uniform dispersion of the beryl particles in matrix. It has been observed that addition of beryl particles significantly improves ultimate tensile strength and hardness properties as compared with that of unreinforced matrix.展开更多
The present investigation aims at developing copper chilled aluminum alloy (LM-13) reinforced with beryl using stir casting method. Matrix alloy was melted in a composite making furnace to a temperature of about 700&#...The present investigation aims at developing copper chilled aluminum alloy (LM-13) reinforced with beryl using stir casting method. Matrix alloy was melted in a composite making furnace to a temperature of about 700°C to which preheated reinforcement particles was added (3 wt.% to 12 wt.% in steps of 3 wt.%), stirred well and finally poured in to an AFS standard mold containing copper end chills of different thickness (10, 15, 20 and 25 mm) placed judiciously for directional solidification. The resulting chilled composites were subjected to microstructural, XRD, mechanical properties (strength and hardness) and tribological behavior.Results of the microstructural and XRD analysis indicate that the chilled castings were sound with good distribution and presence of all the particles. The bonding between beryl reinforcement and Al alloy matrix (LM-13) leads to excellent isotropic properties without?any shrinkage or microporosity. Mechanical characterization indicates that both strength and hardness were maximum in the case of copper chilled MMC containing 9 wt.% and 12 wt.% reinforcement respectively. Strength and hardness of chilled MMC are found to increase by 9.88% and 16.66% as compared against the matrix alloy. It is observed that because of the ceramic (beryl) reinforcement in aluminum alloy, the wear resistance of the chilled composite developed has increased with increase in reinforcement content. At lower load, chilled MMCs exhibited mild wear regime with high coefficient of friction and at higher loads they exhibited severe wear with better wear resistance compared to un-chilled composite. It is observed that the increase in mechanical properties and wear resistance are due to incorporation of beryl reinforcement, the effect of chilling that has resulted in grain refined microstructure with good bonding of the matrix and the reinforcement.展开更多
The formation of the Mufushan granopegmahte was closey related to the Late Yenshanianmultiphase and multistage magmatic activities. More than one generation of beryl and aquamarineoccur in different types of pegmatite...The formation of the Mufushan granopegmahte was closey related to the Late Yenshanianmultiphase and multistage magmatic activities. More than one generation of beryl and aquamarineoccur in different types of pegmatite in the granitcs’ The presence of melt and melt-fluid inclusionsstrongly indhates a melt-solution character of the pegmatitic magma. Forming temperatures of the different generations of beryl in a Na +- K + -Ca2 + -CO3- -Cl- S4 - solution ranges fr0m 990℃ to200℃ touamarine was formed at 720- 180℃ The contents of alkali metals (Na+ + K+ ) in theore-formming solution of aquamarine are lower than those in the bery, but the contents of alkaliearths （Ca) and salinity are higher. The granite was generated by remlting of the basement formation (meta-sedimentary rocks of the Lengiiaki Group) which also served as the souree of ore-formingmaterial. Beryllium in the pegtnatite was transpbrted tnainly in the form of Na2[Be(CO3)2], withpart of it being complexed with Cl- and SO4 During the generation and evolution of thepegmatite, equilibrium might have been reached in the solid-melt-fluid or solid-fluid system. Theintergranular solutions may have reacted with the early crystallized minerals resulting in pot-ash-feldspartiation, albitization and muscovitisation during which the ore-forming elements were mobilized and transported in favour of ore deposition.展开更多
Laser Raman spectrochemical analysis on single inclusion reveals that multi-phase fluid inclusions exist in the Xuebaoding Beryl- Scheelite Vein Deposit. Besides the solid daughter mineral, there are vapor CO2, liquid...Laser Raman spectrochemical analysis on single inclusion reveals that multi-phase fluid inclusions exist in the Xuebaoding Beryl- Scheelite Vein Deposit. Besides the solid daughter mineral, there are vapor CO2, liquid CO2, water-deficient CO2 and salt water solution from its center to the border. A close study on the fluid inclusion components and carbon, oxygen, helium and argon isotope tracing and dating suggests that the volatile-rich ore fluid might derive from postmagmatic fluid and rare element enrichment is the result of the mixture of the plutonic alkali granite with crustal material.展开更多
AT present, it is universally accepted that pegmatite can be crystallized from volatile-rich peraluminousresidual granitic melt in a relatively closed environment from liquidus to solidus. However, there still exist c...AT present, it is universally accepted that pegmatite can be crystallized from volatile-rich peraluminousresidual granitic melt in a relatively closed environment from liquidus to solidus. However, there still exist controversies on the properties of magmatic/hydrothermal transition, the presence of an independentfluid-phase and internal evolution in the system of equilibrium, the crystallization temperature of mineralstructural zones, the time and scale of the occurrence of metasomatosis and the process of rock/fluid interaction. The method of crush-leach analysis of fluid inclusions is still widely used in the study of theproperties of magmatic/hydrothermal transition because analysis of single inclusion is limited by the techniques. Thus the result of crush-leach analysis unavoidably encounters the contamination from inclusionsof multi-generations. Recently, Taylor and Giuliani et al. successively provided some important information about the volatile evolution （mainly H<sub>2</sub>O） of pegmatite and genesis of emerald ore deposits by use展开更多
基金This investigation was supported financially by the Ministry of Education of China （Nos. 01037 and 03178）the National Natural Science Foundation of China （Nos. 40304007 and 40172036） the Fund of State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences （Nos. GPMR0530）.
文摘The tabular beryl found in Huya Country, Sichuan Province is a rare and special member among beryls. Chemical analysis reveals that the beryl is a new type of Cs-rich Na-Li beryl, and the content of alkalis （Li20, Na2O, K2O, Rb2O, Cs2O） is up to 2.41%. The CCD system on the SMART APEX four circle single crystal diffractometer was used in this experiment to determine the structure of the sample accurately. The beryl belongs to the hexagonal system; its space group is P6/mcc. The dimensions of the unit cell are as follows： a = 0.91961（3） nm, c = 0.91969（7） nm, c/a = 1.0000, V= 0.67357 nm3, 7 = 120°, α= 90°, β = 90°. The accurate atomic coordinates of alkali metal ions and other crystallographic parameters are also obtained： Z = 2, the calculated density D = 2.754 g/cm^3 and final R （ I 〉 2 σ （/3）= 0.046 for 5597 reflections. The crystal structure was described by coordination polyhedron. Based on the data gained, a three-dimensional graph of the crystal structure of tabular beryl was made with the ATOMS 6.0 software. The refinement of crystal structure indicates that there are two main reasons for the cause of the tabular configuration： （1） The substitution of Be by Li into the tetrahedral framework weakened the stacked six-sided rings [Si6O18]^12- of the tetrahedral Si; （2） Alkalis （mainly Na and Cs） are too large to substitute in four-fold or six-fold coordination within the structure and are accommodated in the vacant channel. The accommodation of these alkalis strengthened the structure of six-sided rings of the tetrahedral Si. And other alkali metal ions and free volatile molecules such as H2O and CO2 occupy variable positions in the channel. The equation of the electrovalence is Li＋＋Na＋→Be^2＋. According to structural and compositional differences, the monoclinic crystal of tabular beryl is considered to be a new member of the beryl group. Chemical constraints of the environment, namely, the bulk-rock chemistry and the fluid-phase composition and physical-chemical conditions during the growth of the mineral may account for these occurrences of rare elements. In addition, that Li and Be have appro^mate physical parameters is also the key factor for the substitution. The direction of the mineralized hydrothermal liquid and the special occurrence conditions of the beryl such as the pH, temperature and pressure are also considered to be the main causes of the configuration of the tabular beryl.
基金Project 2005CB623701 supported by the National Key Basic Research & Development Program (973) of China
文摘Effects of multivalent metallic cations, such as Ca2+ and Fe3+, on the flotation of spodumene and beryl were studied. The results show that Fe3+ and Ca2+ exhibit efficient activation on the flotation of spodumene and beryl. The ac- tivation of Fe3+ happens quite well within a pH range of 6-9 while the concentration of Fe3+ is 35 mg/L. Efficient acti- vation of Ca2+ takes place over at a pH over 11.6 at a concentration of 140 mg/L. The zeta potential of beryl and spo- dumene shifts slightly to positive values when activated by Ca2+, but markedly by Fe3+. New stretching frequencies of 1594.24 cm-1 and 1587.13 cm-1 have been found in the FTIR spectra of the two minerals after their interaction with Fe3+ and the collector. These new stretching frequencies are the asymmetric stretching frequencies of COO-(carboxyl anion), so thecollector may be chemically absorbed on the surface of Fe3+-activated beryl and spodumene.
文摘Beryllium aluminum cyclosilicate, an ore of beryllium was reinforced in Aluminum matrix to fabricate Al-beryl composites using powder metallurgy. Effect of the content of beryllium aluminum cyclosilicate on microstructural hardness and thermal expansion was studied. The coefficient of thermal expansion of Al-beryl composite was measured in the temperature range between 50oC to 360oC using dilatometer and was theoretically studied using thermo-elastic models, and these models were used to explain abnormalities observed experimentally. The hardness of Al-beryl metal matrix composites increased with the increase in beryl percentage. Vacuum sintering of Al-beryl metal matrix composites at 600oC inhibited excellent bonding between the matrix and the particulate increasing the strength of the composite. The result shows the CTE significantly increased with increasing temperature but decreased with increasing reinforcement. At higher temperatures, CTE of Al-beryl metal matrix composites with 5 wt%, 10 wt% and 15 wt% of beryllium aluminum cyclosilicate was 21 ppm/K, 18.2 ppm/K, and 16.8 ppm/K. The CTE values were found to be comparable with theoretical results. The turner model showed conformance with experimental results, was well suited to the experimental results.
文摘The Beryl Embayment is situated at the south end of the North Viking Graben in the North Sea. Three sets of normal faults, with N-S, NW-SE and NE-SW orientations, have been recognized in the Beryl Embayment. High-resolution subsidence analysis of 73 wells, combined with some seismic data, has been used to document Middle to Late Jurassic subsidence patterns in this area. The high temporal resolution achieved （1 to 2 million years per data point） has also allowed an assessment to be made of temporal evolution of faults with different orientations, and a study made of how and when the East Shetland Fault was linked and controlled sedimentary facies distributions. The results indicate that the East Shetland Fault can be divided into northern and southern parts which were linked together during the Early-Mid Oxfordian. The Mid-Late Jurassic syn-rift phase can be divided into four stages： minor active extension stage during the Bathonian-Middle Callovian, early syn-rotational stage during the Late Callovian-Early-Mid Oxfordian, syn-rotational climax stage during the Late Oxfordian-Early Volgian, and late syn-rotational stage during the Mid-Late Volgian. The results also show that there was a sequential variation of extension direction of active normal faults with different orientations, with an overall shift in the dominant orientation of active normal faults from N-S in the Bathonian-Middle Oxfordian, through NNW-SSE in the Late Oxfordian-Early Volgian （≈N30°E）, to NW-SE （≈N45°E） in the Mid-Late Volgian.
文摘Since most beryls are characterized by prismatic configuration and originate from pegmatite and granite,platy beryl is considered especially rare.Therefore,the aims of this study are to determine the spectrographic and chemical characteristics of the platy beryl;examine the relationships between the spectrographic parameters and alkali elements and discuss the possible genesis of its platy habit based on those results.To accomplish this,ICP-MS,ICP-AES,XRF,XRD and IR analyses were all performed on platy beryls from the Xuebaoding hydrothermal W-Sn-Be deposit.The results revealed that the samples represent alkali-rich beryl which could therefore be named as sodic-lithian and cesium-rich beryl and was showed to be a tetrahedron-substituted beryl.
文摘Beryl is the commercial source of beryllium and several varieties of it are valued as a gemstone.To contribute to understanding the mechanism of beryl formation,we carried out detailed geological,petrographical,and geochemical investigations on beryl mineralization occurrences in the Zabara-Wadi El Gemal(Z-WG)region.This region is an NW-SE trending tract that includes six berylhosting areas.The green gem variety of beryl(emerald)is restricted to phlogopite schist,pegmatite,and quartz veins.Prismatic hexagonal emerald crystals are well-developed in phlogopite schist and pegmatite.The gem variety emerald examined is sodic and Cr-dominant.It contains high concentrations of chromophore transition elements ordering Cr(up to 1511 ppm)>V(up to 242 ppm)>Sc(up to 245 ppm),giving rise to its vivid green color,refl ecting mafic-ultramafic source contribution.Among the investigated emeralds,the Sikait area contains the highest BeO(av.10.76wt.%)concentration.The compositional variability of emeralds is most likely attributed to the contribution from the host rocks.This is revealed by the examined emerald mineralization,for instance;the Abu Rusheid area(one of the best areas exposing rare metal-bearing granitoids)possesses the highest average of trace and REEs concentrations.In contrast,Um Kabu emerald has the highest contents of Co(av.20 ppm),Ni(av.299 ppm),MgO(av.8.2wt.%),Fe_(2)O_(3)(av.3.12wt.%),and CaO(avg.3.4wt.%)relative to other areas,which may be linked to contribution of ultramafic rocks exposed there.The proposed mechanism we suggest for emerald genesis is metasomatic interaction between felsic intrusions,that are enriched with K,Na,Be,Li,and B,with mafic-ultramafic rocks that are enriched in Cr,V,Mg,Fe,and Ca.This interaction is marked by the formation of phlogopite schist,the growth of emerald crystals,and desilicated pegmatite.
文摘Beryl-Al6061 alloy composites having 2-12 wt% of beryl particles were fabricated by liquid metallurgy (stir cast) method. The tensile and wear properties of beryl-Al6061 composites have been evaluated and compared with its base alloy. The results revealed that the Al6061-10 wt% of beryl composites shows an improvement of 15.38% in tensile strength and specific wear rate decreases by 8.9% at normal load of 9.81N when compared to matrix i.e. base alloy. Significant improvement in tensile properties and hardness are noticed as the wt% of the beryl particles increases. The microstructures of the composites were studied to know the uniform dispersion of the beryl particles in matrix. It has been observed that addition of beryl particles significantly improves ultimate tensile strength and hardness properties as compared with that of unreinforced matrix.
文摘The present investigation aims at developing copper chilled aluminum alloy (LM-13) reinforced with beryl using stir casting method. Matrix alloy was melted in a composite making furnace to a temperature of about 700°C to which preheated reinforcement particles was added (3 wt.% to 12 wt.% in steps of 3 wt.%), stirred well and finally poured in to an AFS standard mold containing copper end chills of different thickness (10, 15, 20 and 25 mm) placed judiciously for directional solidification. The resulting chilled composites were subjected to microstructural, XRD, mechanical properties (strength and hardness) and tribological behavior.Results of the microstructural and XRD analysis indicate that the chilled castings were sound with good distribution and presence of all the particles. The bonding between beryl reinforcement and Al alloy matrix (LM-13) leads to excellent isotropic properties without?any shrinkage or microporosity. Mechanical characterization indicates that both strength and hardness were maximum in the case of copper chilled MMC containing 9 wt.% and 12 wt.% reinforcement respectively. Strength and hardness of chilled MMC are found to increase by 9.88% and 16.66% as compared against the matrix alloy. It is observed that because of the ceramic (beryl) reinforcement in aluminum alloy, the wear resistance of the chilled composite developed has increased with increase in reinforcement content. At lower load, chilled MMCs exhibited mild wear regime with high coefficient of friction and at higher loads they exhibited severe wear with better wear resistance compared to un-chilled composite. It is observed that the increase in mechanical properties and wear resistance are due to incorporation of beryl reinforcement, the effect of chilling that has resulted in grain refined microstructure with good bonding of the matrix and the reinforcement.
文摘The formation of the Mufushan granopegmahte was closey related to the Late Yenshanianmultiphase and multistage magmatic activities. More than one generation of beryl and aquamarineoccur in different types of pegmatite in the granitcs’ The presence of melt and melt-fluid inclusionsstrongly indhates a melt-solution character of the pegmatitic magma. Forming temperatures of the different generations of beryl in a Na +- K + -Ca2 + -CO3- -Cl- S4 - solution ranges fr0m 990℃ to200℃ touamarine was formed at 720- 180℃ The contents of alkali metals (Na+ + K+ ) in theore-formming solution of aquamarine are lower than those in the bery, but the contents of alkaliearths （Ca) and salinity are higher. The granite was generated by remlting of the basement formation (meta-sedimentary rocks of the Lengiiaki Group) which also served as the souree of ore-formingmaterial. Beryllium in the pegtnatite was transpbrted tnainly in the form of Na2[Be(CO3)2], withpart of it being complexed with Cl- and SO4 During the generation and evolution of thepegmatite, equilibrium might have been reached in the solid-melt-fluid or solid-fluid system. Theintergranular solutions may have reacted with the early crystallized minerals resulting in pot-ash-feldspartiation, albitization and muscovitisation during which the ore-forming elements were mobilized and transported in favour of ore deposition.
基金This work was supported by NSFC (Grant No. 49873019) NKBRSF Project (Grant No. 1999043205)
文摘Laser Raman spectrochemical analysis on single inclusion reveals that multi-phase fluid inclusions exist in the Xuebaoding Beryl- Scheelite Vein Deposit. Besides the solid daughter mineral, there are vapor CO2, liquid CO2, water-deficient CO2 and salt water solution from its center to the border. A close study on the fluid inclusion components and carbon, oxygen, helium and argon isotope tracing and dating suggests that the volatile-rich ore fluid might derive from postmagmatic fluid and rare element enrichment is the result of the mixture of the plutonic alkali granite with crustal material.
文摘AT present, it is universally accepted that pegmatite can be crystallized from volatile-rich peraluminousresidual granitic melt in a relatively closed environment from liquidus to solidus. However, there still exist controversies on the properties of magmatic/hydrothermal transition, the presence of an independentfluid-phase and internal evolution in the system of equilibrium, the crystallization temperature of mineralstructural zones, the time and scale of the occurrence of metasomatosis and the process of rock/fluid interaction. The method of crush-leach analysis of fluid inclusions is still widely used in the study of theproperties of magmatic/hydrothermal transition because analysis of single inclusion is limited by the techniques. Thus the result of crush-leach analysis unavoidably encounters the contamination from inclusionsof multi-generations. Recently, Taylor and Giuliani et al. successively provided some important information about the volatile evolution （mainly H<sub>2</sub>O） of pegmatite and genesis of emerald ore deposits by use
