Indirect CO2 mineral sequestration that involves two separate steps,with acetic acid as the recycling medium,was limited by a crystallization conversion of only 20% in the second gas-liquid reactive crystallization st...Indirect CO2 mineral sequestration that involves two separate steps,with acetic acid as the recycling medium,was limited by a crystallization conversion of only 20% in the second gas-liquid reactive crystallization step.In this paper,the second carbonation step was greatly improved by coupling reactive crystallization and solvent extraction with the introduction of an organic solvent,tributyl phosphate(TBP),to the process.The effect of the initial concentration of calcium acetate in the aqueous solution on the crystallization conversion was studied experimentally.The obtained calcium conversion was above 40%,which was one time higher than that reported in the literature.Based on the mechanism discussion and thermodynamic equilibrium calculation analysis,it can be concluded that adding TBP to the step can consume the produced acetic acid,and it is in favor of the precipitation of calcium carbonate.While the challenge presented by the strong interaction between calcium ions and acetate ions for further improving crystallization conversion cannot be solved only by the addition of TBP.展开更多
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
文摘Indirect CO2 mineral sequestration that involves two separate steps,with acetic acid as the recycling medium,was limited by a crystallization conversion of only 20% in the second gas-liquid reactive crystallization step.In this paper,the second carbonation step was greatly improved by coupling reactive crystallization and solvent extraction with the introduction of an organic solvent,tributyl phosphate(TBP),to the process.The effect of the initial concentration of calcium acetate in the aqueous solution on the crystallization conversion was studied experimentally.The obtained calcium conversion was above 40%,which was one time higher than that reported in the literature.Based on the mechanism discussion and thermodynamic equilibrium calculation analysis,it can be concluded that adding TBP to the step can consume the produced acetic acid,and it is in favor of the precipitation of calcium carbonate.While the challenge presented by the strong interaction between calcium ions and acetate ions for further improving crystallization conversion cannot be solved only by the addition of TBP.
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.
