The glass and mineral chemistry of basaits examined from the northern central Indian ridge (NCIR) provides an insight into magma genesis around the vicinity of two transform faults: Vityaz (VT) and Vema (VM). T...The glass and mineral chemistry of basaits examined from the northern central Indian ridge (NCIR) provides an insight into magma genesis around the vicinity of two transform faults: Vityaz (VT) and Vema (VM). The studied mid-ocean ridge basalts (MORBs) from the outer ridge flank (VT area) and a near-ridge seamount (VM area) reveal that they are moderately phyric plagioclase basalts composed of plagioclase (phenocryst [An60-90] and groundmass [An35-79]), olivine (Fo81-88), diopside (Wo45-51, En25-37, Fs14-24), and titanomagnetite (FeOt -63.75 wt% and TiO2 -22.69 wt%). The wholerock composition of these basalts has similar Mg# [mole Mg/mole(Mg+Fe2+)] (VT basalt: -0.56-0.58; VM basalt: -0.57), but differ in their total alkali content (VT basalt: -2.65; VM basalt: -3.24). The bulk composition of the magma was gradually depleted in MgO and enriched in FeOt, TiO2, P2O5, and Na2O with progressive fractionation, the basalts were gradually enriched in Y and Zr and depleted in Ni and Cr. In addition, the ∑REE of magma also increased with fractionation, without any change in the (La/ Yb)N value. Glass from the VM seamount shows more fractionated characters (Mg#: 0.56-0.57) compared to the outer ridge flank lava of the VT area (Mg#: 0.63-0.65). This study concludes that present basalts experienced low-pressure crystallization at a relatively shallow depth. The geochemical changes in the NCIR magmas resulted from fractional crystallization at a shallow depth. As a consequence, spinel was the first mineral to crystallize at a pressure 〉10 kbar, followed by Fe-rich olivine at 〈10 kbar pressure.展开更多
Zabuye Salt Lake in Tibet,China is a carbonate-type salt lake,which has some unique characteristics that make it different from other types of salt lakes.The lake is at the latter period in its evolution and contains ...Zabuye Salt Lake in Tibet,China is a carbonate-type salt lake,which has some unique characteristics that make it different from other types of salt lakes.The lake is at the latter period in its evolution and contains liquid and solid resources.Its brine is rich in Li,B,K and other useful minor elements that are of great economic value.We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15℃and 25℃.The crystallization sequence of the primary salts from the brine at 25℃is halite(NaCl)→aphthitalite (3K_2SO_4·Na_2SO_4)→zabuyelite(Li_2CO_3)→trona(Na_2CO_3·NaHCO_3·2H_2O)→thermonatrite (Na_2CO_3·H_2O)→sylvite(KCl),while the sequence is halite(NaCl)→sylvite(KCl)→trona (Na_2CO_3·NaHCO_3·2H_2O)→zabuyelite(Li_2CO_3)→thermonatrite(Na_2CO_3·H_2O)→aphthitalite (3K_2SO_4·Na_2SO_4) at 15℃.They are in accordance with the metastable phase diagram of the Na~+,K~+-Cl^-, CO_3^(2-),SO_4^(2-)-H_2O quinary system at 25℃,except for Na_2CO_3·7H_2O which is replaced by trona and thermonatrite.In the 25℃experiment,zabuyelite(Li_2CO_3) was precipitated in the early stage because Li_2CO_3 is supersaturated in the brine at 25℃,in contrast with that at 15℃,it precipitated in the later stage.Potash was precipitated in the middle and late stages in both experiments,while boron was concentrated in the early and middle stages and precipitated in the late stage.展开更多
Production of lithium carbonate from brines has become the dominate trend in the world from the beginning of this century.Dangxiongcuo,a carbonate-type salt lake,is located in the interior of the Tibetan Plateau,China...Production of lithium carbonate from brines has become the dominate trend in the world from the beginning of this century.Dangxiongcuo,a carbonate-type salt lake,is located in the interior of the Tibetan Plateau,China.As a salt lake deposit,rich in Li,B,K and other useful trace展开更多
Co-gasification of industrial sludge(IS)and coal was an effective approach to achieve harmless and sustainable utilization of IS.The long-term and stable operation of a co-gasification largely depends on fluidity of c...Co-gasification of industrial sludge(IS)and coal was an effective approach to achieve harmless and sustainable utilization of IS.The long-term and stable operation of a co-gasification largely depends on fluidity of coal-ash slag.Herein,the effects of IS addition on the crystallization and viscosity of Shuangmazao(SMZ)coal were investigated by means of high temperature stage coupled with an optical microscope(HTSOM),a scanning electron microscopy coupled with an energy dispersive Xray spectrometry(SEM-EDS),X-ray diffraction(XRD),a Fourier transform infrared spectrometer(FTIR),and FactSage software.The results showed that when the proportion of IS was less than 60%,with the addition of IS,the slag existed in an amorphous form.This was due to the high content of SiO_(2) and Al_(2)O_(3) in SMZ ash and blended ash,which had a high glass-forming ability(GFA).The slag formed at a high temperature had a higher polymerization degree and viscosity,which led to a decrease in the migration ability between ions,and ultimately made the slag difficult to crystallize during the cooling.When the proportion of IS was higher than 60%,the addition of IS increased the CaO and FeO content in the system.As network modifiers,CaO and FeO could provide O^(2−)at a high temperature,which reacted with silicate network structure and continuously destroyed the complexity of network structure,thus reducing the polymerization degree and viscosity of slag.At this time,the migration ability between ions was enhanced,and needle-shaped/rod-shaped crystals were precipitated during the cooling process.Finally,the viscosity calculated by simulation and Einstein-Roscoe empirical formula demonstrated that the addition of IS could significantly improve the fluidity of coal ash and meet the requirements of the liquid slag-tapping gasifier.The purpose of this work was to provide theoretical support for slag flow mechanisms during the gasifier slagging-tapping process and the resource treatment of industrial solid waste.展开更多
基金supported largely by the Office of Naval Research,USA (grant no.:00144-97-1-0925,CLP 0886).This is NIO's contribution # 4362
文摘The glass and mineral chemistry of basaits examined from the northern central Indian ridge (NCIR) provides an insight into magma genesis around the vicinity of two transform faults: Vityaz (VT) and Vema (VM). The studied mid-ocean ridge basalts (MORBs) from the outer ridge flank (VT area) and a near-ridge seamount (VM area) reveal that they are moderately phyric plagioclase basalts composed of plagioclase (phenocryst [An60-90] and groundmass [An35-79]), olivine (Fo81-88), diopside (Wo45-51, En25-37, Fs14-24), and titanomagnetite (FeOt -63.75 wt% and TiO2 -22.69 wt%). The wholerock composition of these basalts has similar Mg# [mole Mg/mole(Mg+Fe2+)] (VT basalt: -0.56-0.58; VM basalt: -0.57), but differ in their total alkali content (VT basalt: -2.65; VM basalt: -3.24). The bulk composition of the magma was gradually depleted in MgO and enriched in FeOt, TiO2, P2O5, and Na2O with progressive fractionation, the basalts were gradually enriched in Y and Zr and depleted in Ni and Cr. In addition, the ∑REE of magma also increased with fractionation, without any change in the (La/ Yb)N value. Glass from the VM seamount shows more fractionated characters (Mg#: 0.56-0.57) compared to the outer ridge flank lava of the VT area (Mg#: 0.63-0.65). This study concludes that present basalts experienced low-pressure crystallization at a relatively shallow depth. The geochemical changes in the NCIR magmas resulted from fractional crystallization at a shallow depth. As a consequence, spinel was the first mineral to crystallize at a pressure 〉10 kbar, followed by Fe-rich olivine at 〈10 kbar pressure.
基金supported by project of K0722 from the Institute of Mineral Resources,Chinese Academy of Geological Sciences
文摘Zabuye Salt Lake in Tibet,China is a carbonate-type salt lake,which has some unique characteristics that make it different from other types of salt lakes.The lake is at the latter period in its evolution and contains liquid and solid resources.Its brine is rich in Li,B,K and other useful minor elements that are of great economic value.We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15℃and 25℃.The crystallization sequence of the primary salts from the brine at 25℃is halite(NaCl)→aphthitalite (3K_2SO_4·Na_2SO_4)→zabuyelite(Li_2CO_3)→trona(Na_2CO_3·NaHCO_3·2H_2O)→thermonatrite (Na_2CO_3·H_2O)→sylvite(KCl),while the sequence is halite(NaCl)→sylvite(KCl)→trona (Na_2CO_3·NaHCO_3·2H_2O)→zabuyelite(Li_2CO_3)→thermonatrite(Na_2CO_3·H_2O)→aphthitalite (3K_2SO_4·Na_2SO_4) at 15℃.They are in accordance with the metastable phase diagram of the Na~+,K~+-Cl^-, CO_3^(2-),SO_4^(2-)-H_2O quinary system at 25℃,except for Na_2CO_3·7H_2O which is replaced by trona and thermonatrite.In the 25℃experiment,zabuyelite(Li_2CO_3) was precipitated in the early stage because Li_2CO_3 is supersaturated in the brine at 25℃,in contrast with that at 15℃,it precipitated in the later stage.Potash was precipitated in the middle and late stages in both experiments,while boron was concentrated in the early and middle stages and precipitated in the late stage.
基金financially supported in part by the National Natural Science Foundation of China (No. 41073050)
文摘Production of lithium carbonate from brines has become the dominate trend in the world from the beginning of this century.Dangxiongcuo,a carbonate-type salt lake,is located in the interior of the Tibetan Plateau,China.As a salt lake deposit,rich in Li,B,K and other useful trace
基金supported by the project of Key Research Plan of Ningxia(2019BEB04030 and 2019BCH01001)the project of CHN Energy Ningxia Coal Industry Co.,Ltd.(NXMY2112).
文摘Co-gasification of industrial sludge(IS)and coal was an effective approach to achieve harmless and sustainable utilization of IS.The long-term and stable operation of a co-gasification largely depends on fluidity of coal-ash slag.Herein,the effects of IS addition on the crystallization and viscosity of Shuangmazao(SMZ)coal were investigated by means of high temperature stage coupled with an optical microscope(HTSOM),a scanning electron microscopy coupled with an energy dispersive Xray spectrometry(SEM-EDS),X-ray diffraction(XRD),a Fourier transform infrared spectrometer(FTIR),and FactSage software.The results showed that when the proportion of IS was less than 60%,with the addition of IS,the slag existed in an amorphous form.This was due to the high content of SiO_(2) and Al_(2)O_(3) in SMZ ash and blended ash,which had a high glass-forming ability(GFA).The slag formed at a high temperature had a higher polymerization degree and viscosity,which led to a decrease in the migration ability between ions,and ultimately made the slag difficult to crystallize during the cooling.When the proportion of IS was higher than 60%,the addition of IS increased the CaO and FeO content in the system.As network modifiers,CaO and FeO could provide O^(2−)at a high temperature,which reacted with silicate network structure and continuously destroyed the complexity of network structure,thus reducing the polymerization degree and viscosity of slag.At this time,the migration ability between ions was enhanced,and needle-shaped/rod-shaped crystals were precipitated during the cooling process.Finally,the viscosity calculated by simulation and Einstein-Roscoe empirical formula demonstrated that the addition of IS could significantly improve the fluidity of coal ash and meet the requirements of the liquid slag-tapping gasifier.The purpose of this work was to provide theoretical support for slag flow mechanisms during the gasifier slagging-tapping process and the resource treatment of industrial solid waste.