The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside gra...The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside grain associated with ringwoodite and lingunite was found in a melt vein of this meteorite.Our electron microprobe,transmission electron microscopic and Raman spectroscopic analyses revealed four silicate phases with different compositions and structures inside this shock-metamorphosed diopside grain,termed phase A,B,C and D in this paper.Phase A is identified as orthorhombic(Ca_(0.663)-Mg_(0.314))SiO_(3)-perovskite which is closely associated with phase B,the vitrified(Mg_(0.642)Ca_(0.290)Fe_(0.098))SiO_(3)perovskite.Phase D is assigned to be(Mg_(0.578)Ca_(0.414))SiO_(3)majorite which is associated with phase C,the vetrified Carich Mg-perovskite with a(Mg_(0.853)Ca_(0.167))SiO_(3)composition.Based on high-pressure and high-temperature experiments,the diopside grain in the melt vein of the Suizhou meteorite would have experienced a P–T regime of 20–24GPa and 1800–>2000℃.Such P–T conditions are high enough for the decomposition of the diopside and the formation of four different silicate phases.The orthorhombic(Ca_(0.663)Mg_(0.314))SiO_(3)perovskite found in the Suizhou L6 chondrite might be considered as the third lower-mantle silicate mineral after bridgmanite and davemaoite after the detailed analyses of its crystal structure and physical properties being completed.展开更多
UV-visible light induced photocatalytic degradation of methylene blue (MB) over Fe-doped diopside was investigated. The structure, composition, morphology and absorption property of UV-visible light of as-prepared sam...UV-visible light induced photocatalytic degradation of methylene blue (MB) over Fe-doped diopside was investigated. The structure, composition, morphology and absorption property of UV-visible light of as-prepared samples were characterized using XRD, SEM, FTIR and UV-vis DRS. The experimental results show that doping Fe3+ induced the formation of some new species in diopside, and promoted light adsorption property of diopside in UV-visible region. Photochemical reactivity of Fe-doped diopside obviously depended on the content of doping Fe3+. The diopside with 1.848% Fe3+ exhibited the superior photocatalytic activity with 95% degradation of MB under UV-visible light for 3 h. The photocatalytic degradation kinetics of MB over all samples showed the first-order reaction nature.展开更多
The exsolutious of diopside and magnetite occur as intergrowth and orient within olivine from the mantle dunite, Luobusa ophiolite, Tibet. The dunite is very fresh with a mineral assemblage of olivine (〉95%) + chr...The exsolutious of diopside and magnetite occur as intergrowth and orient within olivine from the mantle dunite, Luobusa ophiolite, Tibet. The dunite is very fresh with a mineral assemblage of olivine (〉95%) + chromite (1%-4%) + diopside (〈1%). Two types of olivine are found in thin sections: one (Fo = 94) is coarse-grained, elongated with development of kink bands, wavy extinction and irregular margins; and the other (Fo = 96) is fine-grained and poly-angied. Some of the olivine grains contain minor Ca, Cr and Ni. Besides the exsolutions in olivine, three micron-size inclusions are also discovered. Analyzed through energy dispersive system (EDS) with unitary analytical method, the average compositions of the inclusions are: Na20, 3.12%-3.84%; MgO, 19.51%-23.79%; Al2O3, 9.33%-11.31%; SiO2, 44.89%-46.29%; CaO, 11.46%-12.90%; Cr2O3, 0.74%-2.29%; FeO, 4.26%- 5.27%, which is quite similar to those of amphibole. Diopside is anhedral f'dling between olivines, or as micro-inclusions oriented in olivines. Chromite appears euhedral distributed between olivines, sometimes with apparent compositional zone. From core to rim of the chromite, Fe content increases and Cr decreases; and A! and Mg drop greatly on the rim. There is always incomplete magnetite zone around the chromite. Compared with the nodular chromite in the same section, the euhedral chromite has higher Fe3O4 and lower MgCr2O4 and MgAI2O4 end member contents, which means it formed under higher oxygen fugacity environment. With a geothermometer estimation, the equilibrium crystalline temperature is 820℃-960℃ for olivine and nodular chromite, 630℃-770℃ for olivine and euhedral chromite, and 350℃-550℃ for olivine and exsoluted magnetite, showing that the exsolutions occurred late at low temperature. Thus we propose that previously depleted mantle harzburgite reacted with the melt containing Na, Al and Ca, and produced an olivine solid solution added with Na^+, Al^3+, Ca^2+, Fe^3+, Cr^3+. With temperature decreasing, the olivine solid solution decomposed; and Fe^3+, Cr^3+ diffused into magnetite and Ca^2+ and Na^+ into clinopyroxene, both of which formed intergrowth textures. A few Fe^3+ and Cr^3+ entered interstitial chromite. Through later tectonism, the peridotite recrystallized and formed deformational coarse grained olivine, fine grained and poly-angled olivine, and euhedral grained chromite. Due to the fast cooling rate of the rock or rapid tectonic emplacement, the exsolution textures in olivine and compositional zones of chromite are preserved.展开更多
The mechanisms of interaction between tannic acid and calcium ions either added externally to or inherently present in the (?)olution ( dissociated from mineral surface ) , are studied by the use of Inductively Couple...The mechanisms of interaction between tannic acid and calcium ions either added externally to or inherently present in the (?)olution ( dissociated from mineral surface ) , are studied by the use of Inductively Coupled Plasma Atomic Emission Spectroscopy ( ICP-AES ) , Ultraviolet Spectroscopy (UV). It is found that wollastonite has a high solubility in the concentration of calcium ions, calcium ions are able to interact with tannic acid.展开更多
The depression mechanisms of tannin on the diopside surface have been studied by the rise of Infrared spectroscopy (IR), simulated pulp and mixed solution tests, It is found that the first order hydroxy completes of c...The depression mechanisms of tannin on the diopside surface have been studied by the rise of Infrared spectroscopy (IR), simulated pulp and mixed solution tests, It is found that the first order hydroxy completes of calcium are able to interact with tannin, and to form chemical complexes. es. The functional groups in tannin molecules participating in the chemical complexation are the hydroxyl groups, and carboxyl groups derived from the hydrolysis of hydroxyl groups.展开更多
The floatabilities of single mineral samples of Tvollas-tonite and diopside have been studied with addition of a cationic collector , dodecylamine hydrochloride (DDA ?HC1) , and modifiers. A mixture of two minerals wa...The floatabilities of single mineral samples of Tvollas-tonite and diopside have been studied with addition of a cationic collector , dodecylamine hydrochloride (DDA ?HC1) , and modifiers. A mixture of two minerals was successfully separated , when DDA ?HC1 and tannic acid (as depressant)were used together . The interaction between tannic acid and wollastonite and diopside in the pulp and the adsorption of tannic acid on the surface of the two minerals was sttidide with the help of ultra-violet (UV) spectroscopy and X-ray photoelectron spectroscopy (XPS) , re-spectively.展开更多
Anorthite -diopside ceramics were prepared by sintering iron ore railings, calcium carbonate, and silicon dioxide. Rare-earth cerium nitrate was evaluated as a sintering additive for the ceramics, whose mass percentag...Anorthite -diopside ceramics were prepared by sintering iron ore railings, calcium carbonate, and silicon dioxide. Rare-earth cerium nitrate was evaluated as a sintering additive for the ceramics, whose mass percentage was 3% , 5%, 7% , 9% , and 11% , respectively. The sinterability of anorthite - diopside ceramics during heat treatment was confirmed hy X-ray diffiaction, transmission^scanning electron micrascopy, thermogravi- metric analysis- differential thermal analysis, and hotstage microscopy, respectively. The obtained results show that the density of ceramics gradnally increases, while the sintering temperature and sintering activation energy of anorthite -diopside ceramics are notably decreased with the increasing cerium content. Rare-earth cerium not only is beneficial to the complete reaction of raw materials, but a/so can accelerate the mass transfer process through forming eutectic phase with aluminum.展开更多
The elastic properties of glasses along Diopside (CaMgSi2O6)-Jadeite (NaAlSi2O6) join (Dix - Jd1-x where x=20, 40, 60, 80, 100 mole %), were obtained by the ultrasonic echography technique, at room temperature. The co...The elastic properties of glasses along Diopside (CaMgSi2O6)-Jadeite (NaAlSi2O6) join (Dix - Jd1-x where x=20, 40, 60, 80, 100 mole %), were obtained by the ultrasonic echography technique, at room temperature. The correlation of elastic moduli with the atomic packing density of these glasses was discussed. The derived experimental values of Young’s modulus, bulk modulus, shear modulus and Poisson’s ratio for investigated glasses were compared with those theoretically calculated values in terms of the Makishima–Mackenzie model and the modified model presented by Rocherulle.展开更多
Numerous empirical and experimental studies have documented the consumption of orthopyroxene and production of clinopyroxene in mantle peridotite during carbonatite metasomatism,whereas little attention has been paid ...Numerous empirical and experimental studies have documented the consumption of orthopyroxene and production of clinopyroxene in mantle peridotite during carbonatite metasomatism,whereas little attention has been paid to whether and how olivine is compositionally modified through the same process of carbonatite metasomatism.Here,we present the discovery of well-preserved reaction features in olivine from typical calciocarbonatites from Sri Lanka.The olivine grains experienced serpentinization along the cracks and in their rims and are generally surrounded outwardly by serpentine,tremolite and diopside zones.The inner serpentine zone is dominated by serpentine with tiny magnetite,whereas the mantle tremolite zone is characterized by euhedral tremolite and intergrowth of dolomite with small amounts of serpentine relics and diopside.The outer diopside zone shows spongy texture and commonly encloses olivine,serpentine,tremolite and dolomite,which are also observed in interstitial diopside grains in the carbonatites.Compositional profile analyses reveal that these olivine grains display decreasing FeO and increasing MgO contents and thus elevating Fo values from their cores to the reaction rims,while the serpentine inherits compositions from the olivine.Elemental mapping images demonstrate outward diffusion of Si and Mg in the serpentine zones and contribution of Ca from carbonatite melts during tremolite formation.Further interaction with carbonatite melts produced Si-and Mg-poor and Ca-rich diopside relative to the reactant tremolite.These observations suggest that the interaction with carbonatite melts first transformed olivine to diopside through serpentinization,followed by tremolitization.The diopside formed through olivine-carbonatite melt interaction is anomalously depleted in Na and Al and enriched in Ca,which are distinct from those generated in interactions between orthopyroxene and both carbonatite and silicate melts.This implies that for the first time some wehrlites and clinopyroxenites in the mantle might originate from intense interaction between peridotites(including dunite)and carbonatite melts.This mechanism can be invoked to explain the formation of other global occurrences of wehrlite and clinopyroxenite suites.展开更多
Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydro...Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydrous uvarovite garnet having Cr_(2)O_(3) upto 19.66 wt% and CaO of 32.12–35.14 wt% in the serpentinized mantle peridotites of Naga Hills Ophiolite(NHO), India. They occur in association with low-Cr diopsides. They are enriched in LILE(Ba, Sr), LREEs, with fractionating LREE-MREE [avg.(La/Sm)_(N) = 2.16] with flat MREE/HREE patterns [avg.(Sm/Yb)_(N) = 0.95]. Raman spectra indicate the presence of hydroxyl(OH^(–)) peaks from 3500 to 3700 cm^(-1). Relative abundances in fluid mobile elements and their close association with clinopyroxenes are suggestive of the formation of uvarovite garnets through low temperature metasomatic alteration of low-Cr diopsides by hydrothermal slab fluids. The high LREE concentration and absence of Eu anomaly in the garnet further attest to alkaline nature of the transporting slab dehydrated fluid rather the involvement of low-p H solution. The chemical characteristics of the hydroxyl bearing uvarovite hosted by the mantle peridotite of NHO deviate from the classical features of uvarovite garnet, and their origin is attributed to the fluid-induced metasomatism of the sub arc mantle wedge in a suprasubduction zone regime.展开更多
Mechanical strength and its long-term stability of bioceramic scaffolds is still a problem to treat the osteonecrosis of the femoral head.Considering the long-term stability of diopside(DIO)ceramic but poor mechanical...Mechanical strength and its long-term stability of bioceramic scaffolds is still a problem to treat the osteonecrosis of the femoral head.Considering the long-term stability of diopside(DIO)ceramic but poor mechanical strength,we developed the DIO-based porous bioceramic composites via dilute magnesium substituted wollastonite reinforcing and three-dimensional(3D)printing.The experimental results showed that the secondary phase(i.e.10%magnesium substituting calcium silicate;CSM10)could readily improve the sintering property of the bioceramic composites(DIO/CSM10-x,x=0-30)with increasing the CSM10 content from 0%to 30%,and the presence of the CSM10 also improved the biomimetic apatite mineralization ability in the pore struts of the scaffolds.Furthermore,the flexible strength(12.5 -30 MPa)and compressive strength(14-37 MPa)of the 3D printed porous bioceramics remarkably increased with increasing CSM10 content,and the compressive strength of DIO/CSM10-30 showed a limited decay(from 37 MPa to 29 MPa)in the Tris buffer solution for a long time stage(8 weeks).These findings suggest that the new CSM10-reinforced diopside porous constructs possess excellent mechanical properties and can potentially be used to the clinic,especially for the treatment of osteonecrosis of the femoral head work as a bioceramic rod.展开更多
Among the various xenoliths entrained by the Cenozoic Hannuoba basalts, peridotite is the most abundant one. The trace elements of the diopsides from the peridotite xenoliths were analysed by LA-ICP-MS. The overall de...Among the various xenoliths entrained by the Cenozoic Hannuoba basalts, peridotite is the most abundant one. The trace elements of the diopsides from the peridotite xenoliths were analysed by LA-ICP-MS. The overall depletion and some heterogeneity of the continental mantle beneath northern North China Craton were indicated by the characteristics of the trace elements. The ∑REE amount in diopside correlates with the Cr/(Cr+Al) ratio of diopside which is indicative of xenolith’s partial melting degree. As the peridotite hosts and pyroxenite veins show similar REE distribution patterns, the composite xenoliths are probably formed by mantle deformation, rather than by the late metasomatism of mantle fluids/melts.展开更多
The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2(CMAS) glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry(DSC).The structure and phase analyse...The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2(CMAS) glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry(DSC).The structure and phase analyses were made by Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD).The experiment results show that the endothermic peak temperature about 760℃ is associated with transition and the exothermic peak temperature about 1000℃ is associated with crystallization.The crystallization peak temperature decreases with increasing the Fe203 content.The crystallization mechanism is changed from two-dimensional crystallization to one-dimensional growth,and the intensity of diopside peaks becomes stronger gradually.There is a saltation for the crystallization temperature with the addition of 0.5%Fe2O3 due to the decomposition of Fe2O3.Si-O-Si,O-Si-O and T-O-T(T=Si,Fe,Al) linkages are observed in Fe2O3-CaO-MgO-Al2O3-SiO2 glass.展开更多
The wear performance of fine grain alumina ball adding diopside as fluxing agent are reported for the first time in this paper. The ball (average grain size 3 mum) exhibits excellent toughness and low wear rates. Plou...The wear performance of fine grain alumina ball adding diopside as fluxing agent are reported for the first time in this paper. The ball (average grain size 3 mum) exhibits excellent toughness and low wear rates. Ploughing grooves and traces of micro-cutting occur at the place with no pore. And the wear process is mainly caused by plastic deformation mechanism. Yet, the ordinary alumina balls (average grain size 6 and 15 mum) are brittle and the wear rates are high. The intergranular and transgranular dropping pits occur, and the wear process in mainly caused by brittle fracture mechanism.展开更多
The crystallization behavior and mechanism of CaO–Al2O3–MgO–SiO2(CAMS)-based diopside glass ceramics with nano-ZrO2 nucleators and CeO2 agents have been investigated.The use of nanoscale ZrO2 as nucleators is favor...The crystallization behavior and mechanism of CaO–Al2O3–MgO–SiO2(CAMS)-based diopside glass ceramics with nano-ZrO2 nucleators and CeO2 agents have been investigated.The use of nanoscale ZrO2 as nucleators is favorable to the crystallization of glass ceramic at a relatively lower temperature due to the reduction of the activation energy, while the activation energy is increased after adding the CeO2 agent.The microstructure and orientation have been analyzed by scanning electron microscopy and electron backscatter diffraction.Two discernible layers are observed, featured in glass and crystalline phases, respectively.Remarkably textured polycrystalline diopsides are verified for the samples(A and B)free of CeO2 agents, with c-axes perpendicular to the interface of the two layers.Comparatively, the c-axes of diopside grains of the sample(C) with CeO2 agents are proved to be parallel to the interface.Nanocrystals are detected in the vicinity of the interface for sample C.展开更多
When liquid steel slag produced from steelmaking process was treated into the post-cold slag by conventional methods,the great deal of slag heat was dissipated into the environment,causing a lot of energy waste and en...When liquid steel slag produced from steelmaking process was treated into the post-cold slag by conventional methods,the great deal of slag heat was dissipated into the environment,causing a lot of energy waste and environmental pollution.In this study,a novel approach of direct utilization of hot steel slag as a raw material and slag heat for the production of glass-ceramics was proposed and experimentally tested.In order to simulate liquid slag from steelmaking electric furnace,40%water-quenched slag was remelted at 1 450℃and then mixed with 60%melting additives(silica powder,alumina powder and sodium oxide, etc.)and subsequently melted together at 1 500℃for 1 h into modified liquid slag which was cast,heat-treated, annealed and transformed into glass-ceramics.The heat-treated glass samples were investigated using differential thermal analysis(DTA),X-ray diffraction(XRD),and scanning electron microscopy(SEM). The results show that dominant crystalline phase is diopside[CaFe(SiO_3)_2]and the shape of the crystal is like the granule,diameter is about 0.2 -0.6μm.A glass-ceramic with nucleation temperature of 695℃for two hours and crystallization temperature of 893℃for one hour and 1 163℃for half-hour exhibited the best combination of properties.This method of slag mixed with melting additives to adjust the composition of the parent glass is important for the industrial production of glass-ceramics by direct utilization of hot steel slag.展开更多
文摘The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside grain associated with ringwoodite and lingunite was found in a melt vein of this meteorite.Our electron microprobe,transmission electron microscopic and Raman spectroscopic analyses revealed four silicate phases with different compositions and structures inside this shock-metamorphosed diopside grain,termed phase A,B,C and D in this paper.Phase A is identified as orthorhombic(Ca_(0.663)-Mg_(0.314))SiO_(3)-perovskite which is closely associated with phase B,the vitrified(Mg_(0.642)Ca_(0.290)Fe_(0.098))SiO_(3)perovskite.Phase D is assigned to be(Mg_(0.578)Ca_(0.414))SiO_(3)majorite which is associated with phase C,the vetrified Carich Mg-perovskite with a(Mg_(0.853)Ca_(0.167))SiO_(3)composition.Based on high-pressure and high-temperature experiments,the diopside grain in the melt vein of the Suizhou meteorite would have experienced a P–T regime of 20–24GPa and 1800–>2000℃.Such P–T conditions are high enough for the decomposition of the diopside and the formation of four different silicate phases.The orthorhombic(Ca_(0.663)Mg_(0.314))SiO_(3)perovskite found in the Suizhou L6 chondrite might be considered as the third lower-mantle silicate mineral after bridgmanite and davemaoite after the detailed analyses of its crystal structure and physical properties being completed.
基金Projects (50874029, 51090384) supported by the National Natural Science Foundation of China
文摘UV-visible light induced photocatalytic degradation of methylene blue (MB) over Fe-doped diopside was investigated. The structure, composition, morphology and absorption property of UV-visible light of as-prepared samples were characterized using XRD, SEM, FTIR and UV-vis DRS. The experimental results show that doping Fe3+ induced the formation of some new species in diopside, and promoted light adsorption property of diopside in UV-visible region. Photochemical reactivity of Fe-doped diopside obviously depended on the content of doping Fe3+. The diopside with 1.848% Fe3+ exhibited the superior photocatalytic activity with 95% degradation of MB under UV-visible light for 3 h. The photocatalytic degradation kinetics of MB over all samples showed the first-order reaction nature.
文摘The exsolutious of diopside and magnetite occur as intergrowth and orient within olivine from the mantle dunite, Luobusa ophiolite, Tibet. The dunite is very fresh with a mineral assemblage of olivine (〉95%) + chromite (1%-4%) + diopside (〈1%). Two types of olivine are found in thin sections: one (Fo = 94) is coarse-grained, elongated with development of kink bands, wavy extinction and irregular margins; and the other (Fo = 96) is fine-grained and poly-angied. Some of the olivine grains contain minor Ca, Cr and Ni. Besides the exsolutions in olivine, three micron-size inclusions are also discovered. Analyzed through energy dispersive system (EDS) with unitary analytical method, the average compositions of the inclusions are: Na20, 3.12%-3.84%; MgO, 19.51%-23.79%; Al2O3, 9.33%-11.31%; SiO2, 44.89%-46.29%; CaO, 11.46%-12.90%; Cr2O3, 0.74%-2.29%; FeO, 4.26%- 5.27%, which is quite similar to those of amphibole. Diopside is anhedral f'dling between olivines, or as micro-inclusions oriented in olivines. Chromite appears euhedral distributed between olivines, sometimes with apparent compositional zone. From core to rim of the chromite, Fe content increases and Cr decreases; and A! and Mg drop greatly on the rim. There is always incomplete magnetite zone around the chromite. Compared with the nodular chromite in the same section, the euhedral chromite has higher Fe3O4 and lower MgCr2O4 and MgAI2O4 end member contents, which means it formed under higher oxygen fugacity environment. With a geothermometer estimation, the equilibrium crystalline temperature is 820℃-960℃ for olivine and nodular chromite, 630℃-770℃ for olivine and euhedral chromite, and 350℃-550℃ for olivine and exsoluted magnetite, showing that the exsolutions occurred late at low temperature. Thus we propose that previously depleted mantle harzburgite reacted with the melt containing Na, Al and Ca, and produced an olivine solid solution added with Na^+, Al^3+, Ca^2+, Fe^3+, Cr^3+. With temperature decreasing, the olivine solid solution decomposed; and Fe^3+, Cr^3+ diffused into magnetite and Ca^2+ and Na^+ into clinopyroxene, both of which formed intergrowth textures. A few Fe^3+ and Cr^3+ entered interstitial chromite. Through later tectonism, the peridotite recrystallized and formed deformational coarse grained olivine, fine grained and poly-angled olivine, and euhedral grained chromite. Due to the fast cooling rate of the rock or rapid tectonic emplacement, the exsolution textures in olivine and compositional zones of chromite are preserved.
文摘The mechanisms of interaction between tannic acid and calcium ions either added externally to or inherently present in the (?)olution ( dissociated from mineral surface ) , are studied by the use of Inductively Coupled Plasma Atomic Emission Spectroscopy ( ICP-AES ) , Ultraviolet Spectroscopy (UV). It is found that wollastonite has a high solubility in the concentration of calcium ions, calcium ions are able to interact with tannic acid.
文摘The depression mechanisms of tannin on the diopside surface have been studied by the rise of Infrared spectroscopy (IR), simulated pulp and mixed solution tests, It is found that the first order hydroxy completes of calcium are able to interact with tannin, and to form chemical complexes. es. The functional groups in tannin molecules participating in the chemical complexation are the hydroxyl groups, and carboxyl groups derived from the hydrolysis of hydroxyl groups.
文摘The floatabilities of single mineral samples of Tvollas-tonite and diopside have been studied with addition of a cationic collector , dodecylamine hydrochloride (DDA ?HC1) , and modifiers. A mixture of two minerals was successfully separated , when DDA ?HC1 and tannic acid (as depressant)were used together . The interaction between tannic acid and wollastonite and diopside in the pulp and the adsorption of tannic acid on the surface of the two minerals was sttidide with the help of ultra-violet (UV) spectroscopy and X-ray photoelectron spectroscopy (XPS) , re-spectively.
基金supported by the Program for New Century Excellent Talents(NCET-13-0408)
文摘Anorthite -diopside ceramics were prepared by sintering iron ore railings, calcium carbonate, and silicon dioxide. Rare-earth cerium nitrate was evaluated as a sintering additive for the ceramics, whose mass percentage was 3% , 5%, 7% , 9% , and 11% , respectively. The sinterability of anorthite - diopside ceramics during heat treatment was confirmed hy X-ray diffiaction, transmission^scanning electron micrascopy, thermogravi- metric analysis- differential thermal analysis, and hotstage microscopy, respectively. The obtained results show that the density of ceramics gradnally increases, while the sintering temperature and sintering activation energy of anorthite -diopside ceramics are notably decreased with the increasing cerium content. Rare-earth cerium not only is beneficial to the complete reaction of raw materials, but a/so can accelerate the mass transfer process through forming eutectic phase with aluminum.
文摘The elastic properties of glasses along Diopside (CaMgSi2O6)-Jadeite (NaAlSi2O6) join (Dix - Jd1-x where x=20, 40, 60, 80, 100 mole %), were obtained by the ultrasonic echography technique, at room temperature. The correlation of elastic moduli with the atomic packing density of these glasses was discussed. The derived experimental values of Young’s modulus, bulk modulus, shear modulus and Poisson’s ratio for investigated glasses were compared with those theoretically calculated values in terms of the Makishima–Mackenzie model and the modified model presented by Rocherulle.
基金financially supported by the Youth Innovation Promotion Association,Chinese Academy of Sciences。
文摘Numerous empirical and experimental studies have documented the consumption of orthopyroxene and production of clinopyroxene in mantle peridotite during carbonatite metasomatism,whereas little attention has been paid to whether and how olivine is compositionally modified through the same process of carbonatite metasomatism.Here,we present the discovery of well-preserved reaction features in olivine from typical calciocarbonatites from Sri Lanka.The olivine grains experienced serpentinization along the cracks and in their rims and are generally surrounded outwardly by serpentine,tremolite and diopside zones.The inner serpentine zone is dominated by serpentine with tiny magnetite,whereas the mantle tremolite zone is characterized by euhedral tremolite and intergrowth of dolomite with small amounts of serpentine relics and diopside.The outer diopside zone shows spongy texture and commonly encloses olivine,serpentine,tremolite and dolomite,which are also observed in interstitial diopside grains in the carbonatites.Compositional profile analyses reveal that these olivine grains display decreasing FeO and increasing MgO contents and thus elevating Fo values from their cores to the reaction rims,while the serpentine inherits compositions from the olivine.Elemental mapping images demonstrate outward diffusion of Si and Mg in the serpentine zones and contribution of Ca from carbonatite melts during tremolite formation.Further interaction with carbonatite melts produced Si-and Mg-poor and Ca-rich diopside relative to the reactant tremolite.These observations suggest that the interaction with carbonatite melts first transformed olivine to diopside through serpentinization,followed by tremolitization.The diopside formed through olivine-carbonatite melt interaction is anomalously depleted in Na and Al and enriched in Ca,which are distinct from those generated in interactions between orthopyroxene and both carbonatite and silicate melts.This implies that for the first time some wehrlites and clinopyroxenites in the mantle might originate from intense interaction between peridotites(including dunite)and carbonatite melts.This mechanism can be invoked to explain the formation of other global occurrences of wehrlite and clinopyroxenite suites.
基金the funding received from the Science and Engineering Research Board (SERB), Govt. of India under GAP 3291funded by Ministry of Earth Science (MoES) with project reference number Mo ES/ P.O. (Seismic) 8 (09)-Geochron/2012。
文摘Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydrous uvarovite garnet having Cr_(2)O_(3) upto 19.66 wt% and CaO of 32.12–35.14 wt% in the serpentinized mantle peridotites of Naga Hills Ophiolite(NHO), India. They occur in association with low-Cr diopsides. They are enriched in LILE(Ba, Sr), LREEs, with fractionating LREE-MREE [avg.(La/Sm)_(N) = 2.16] with flat MREE/HREE patterns [avg.(Sm/Yb)_(N) = 0.95]. Raman spectra indicate the presence of hydroxyl(OH^(–)) peaks from 3500 to 3700 cm^(-1). Relative abundances in fluid mobile elements and their close association with clinopyroxenes are suggestive of the formation of uvarovite garnets through low temperature metasomatic alteration of low-Cr diopsides by hydrothermal slab fluids. The high LREE concentration and absence of Eu anomaly in the garnet further attest to alkaline nature of the transporting slab dehydrated fluid rather the involvement of low-p H solution. The chemical characteristics of the hydroxyl bearing uvarovite hosted by the mantle peridotite of NHO deviate from the classical features of uvarovite garnet, and their origin is attributed to the fluid-induced metasomatism of the sub arc mantle wedge in a suprasubduction zone regime.
基金This work was supported by the Zhejiang Provincial Natural Science Foundation of China(LZ14E020001,LQ14H060003)gs2:National Science Foundation of China(51372218,81271956,81301326)the Science and Technology Department of Zhejiang Province Foundation(2015C33119,2014C33202).
文摘Mechanical strength and its long-term stability of bioceramic scaffolds is still a problem to treat the osteonecrosis of the femoral head.Considering the long-term stability of diopside(DIO)ceramic but poor mechanical strength,we developed the DIO-based porous bioceramic composites via dilute magnesium substituted wollastonite reinforcing and three-dimensional(3D)printing.The experimental results showed that the secondary phase(i.e.10%magnesium substituting calcium silicate;CSM10)could readily improve the sintering property of the bioceramic composites(DIO/CSM10-x,x=0-30)with increasing the CSM10 content from 0%to 30%,and the presence of the CSM10 also improved the biomimetic apatite mineralization ability in the pore struts of the scaffolds.Furthermore,the flexible strength(12.5 -30 MPa)and compressive strength(14-37 MPa)of the 3D printed porous bioceramics remarkably increased with increasing CSM10 content,and the compressive strength of DIO/CSM10-30 showed a limited decay(from 37 MPa to 29 MPa)in the Tris buffer solution for a long time stage(8 weeks).These findings suggest that the new CSM10-reinforced diopside porous constructs possess excellent mechanical properties and can potentially be used to the clinic,especially for the treatment of osteonecrosis of the femoral head work as a bioceramic rod.
文摘Among the various xenoliths entrained by the Cenozoic Hannuoba basalts, peridotite is the most abundant one. The trace elements of the diopsides from the peridotite xenoliths were analysed by LA-ICP-MS. The overall depletion and some heterogeneity of the continental mantle beneath northern North China Craton were indicated by the characteristics of the trace elements. The ∑REE amount in diopside correlates with the Cr/(Cr+Al) ratio of diopside which is indicative of xenolith’s partial melting degree. As the peridotite hosts and pyroxenite veins show similar REE distribution patterns, the composite xenoliths are probably formed by mantle deformation, rather than by the late metasomatism of mantle fluids/melts.
基金Projects(51264023,51364020,U1202271)supported by the National Natural Science Foundation of ChinaProject(IRT1250)supported by the Program for Innovative Research Team in University of Ministry of Education of ChinaProject(2014HA003)supported by the Science and Technology Leading Talent of Yunnan Province,China
文摘The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2(CMAS) glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry(DSC).The structure and phase analyses were made by Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD).The experiment results show that the endothermic peak temperature about 760℃ is associated with transition and the exothermic peak temperature about 1000℃ is associated with crystallization.The crystallization peak temperature decreases with increasing the Fe203 content.The crystallization mechanism is changed from two-dimensional crystallization to one-dimensional growth,and the intensity of diopside peaks becomes stronger gradually.There is a saltation for the crystallization temperature with the addition of 0.5%Fe2O3 due to the decomposition of Fe2O3.Si-O-Si,O-Si-O and T-O-T(T=Si,Fe,Al) linkages are observed in Fe2O3-CaO-MgO-Al2O3-SiO2 glass.
基金Funded by Hubei Province Key ScientificTechnological Development Foundation (No.951P0301).
文摘The wear performance of fine grain alumina ball adding diopside as fluxing agent are reported for the first time in this paper. The ball (average grain size 3 mum) exhibits excellent toughness and low wear rates. Ploughing grooves and traces of micro-cutting occur at the place with no pore. And the wear process is mainly caused by plastic deformation mechanism. Yet, the ordinary alumina balls (average grain size 6 and 15 mum) are brittle and the wear rates are high. The intergranular and transgranular dropping pits occur, and the wear process in mainly caused by brittle fracture mechanism.
基金Project supported by the National Natural Sciences Foundation of China(Grant No.51590881)the National Key Research Program of China(Grant No.2016YFB0700903)+1 种基金the Inner Mongolia Science and Technology Major Project of China 2016the Fujian Institute of Innovation,Chinese Academy of Sciences(Grant No.FJCXY18040302)
文摘The crystallization behavior and mechanism of CaO–Al2O3–MgO–SiO2(CAMS)-based diopside glass ceramics with nano-ZrO2 nucleators and CeO2 agents have been investigated.The use of nanoscale ZrO2 as nucleators is favorable to the crystallization of glass ceramic at a relatively lower temperature due to the reduction of the activation energy, while the activation energy is increased after adding the CeO2 agent.The microstructure and orientation have been analyzed by scanning electron microscopy and electron backscatter diffraction.Two discernible layers are observed, featured in glass and crystalline phases, respectively.Remarkably textured polycrystalline diopsides are verified for the samples(A and B)free of CeO2 agents, with c-axes perpendicular to the interface of the two layers.Comparatively, the c-axes of diopside grains of the sample(C) with CeO2 agents are proved to be parallel to the interface.Nanocrystals are detected in the vicinity of the interface for sample C.
文摘When liquid steel slag produced from steelmaking process was treated into the post-cold slag by conventional methods,the great deal of slag heat was dissipated into the environment,causing a lot of energy waste and environmental pollution.In this study,a novel approach of direct utilization of hot steel slag as a raw material and slag heat for the production of glass-ceramics was proposed and experimentally tested.In order to simulate liquid slag from steelmaking electric furnace,40%water-quenched slag was remelted at 1 450℃and then mixed with 60%melting additives(silica powder,alumina powder and sodium oxide, etc.)and subsequently melted together at 1 500℃for 1 h into modified liquid slag which was cast,heat-treated, annealed and transformed into glass-ceramics.The heat-treated glass samples were investigated using differential thermal analysis(DTA),X-ray diffraction(XRD),and scanning electron microscopy(SEM). The results show that dominant crystalline phase is diopside[CaFe(SiO_3)_2]and the shape of the crystal is like the granule,diameter is about 0.2 -0.6μm.A glass-ceramic with nucleation temperature of 695℃for two hours and crystallization temperature of 893℃for one hour and 1 163℃for half-hour exhibited the best combination of properties.This method of slag mixed with melting additives to adjust the composition of the parent glass is important for the industrial production of glass-ceramics by direct utilization of hot steel slag.