The influence of NaCl-CaCl2 on thermal decomposition of REPO4（RE： Ce, La, Nd, Th） with CaO was studied. The heat decomposing process of REPO4 was tested with TG-DTA experiments. The results showed that the decompos...The influence of NaCl-CaCl2 on thermal decomposition of REPO4（RE： Ce, La, Nd, Th） with CaO was studied. The heat decomposing process of REPO4 was tested with TG-DTA experiments. The results showed that the decomposition temperature of REPO4 with CaO was reduced because of adding NaCl-CaCl2 mixture （NaCl：CaCl2 = 1：1 ）. The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with CaO was studied. The results showed that the decomposition ratio of REPO4with CaO was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.展开更多
对恒温热处理后的 NaCl-CaCl_2样品进行差热分析、室温和高温 X 射线粉末照相,并对恒温热处理快速淬火后样品进行了 X 射线衍射结构分析。实验证明了 NaCl-CaCl_2二元体系不存在包晶反应所形成的化合物4NaCl·CaCl_2,属共晶体系,共...对恒温热处理后的 NaCl-CaCl_2样品进行差热分析、室温和高温 X 射线粉末照相,并对恒温热处理快速淬火后样品进行了 X 射线衍射结构分析。实验证明了 NaCl-CaCl_2二元体系不存在包晶反应所形成的化合物4NaCl·CaCl_2,属共晶体系,共晶温度为773K,共晶组成为49mol%NaCl、5lmol%CaCl_2;在 NaCl 一侧有固溶体存在;在共晶温度处的固溶度约为18mol%CaCl_2。该二元系的实验测定结果与理论计算结果吻合也很好。展开更多
By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been checked.It is.a simple eutectic system with a solid solubility in the sodium chloride side...By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been checked.It is.a simple eutectic system with a solid solubility in the sodium chloride side.The eutectic point is at 773K,49 mol% NaCl.The experimental results,especially those of the X-ray diffraction studies have showed that the incongruent compound 4NaCl-CaCl_2 does not exist in the NaCl-CaCl_2 system.展开更多
The composition of fluid inclusions in the H_2O-NaCl-CaCl_2 system has been generally graphically estimated using the melting temperatures of hydrohalite(T_(m-HH))and ice(T_(m-ice)).Here we present two equations that ...The composition of fluid inclusions in the H_2O-NaCl-CaCl_2 system has been generally graphically estimated using the melting temperatures of hydrohalite(T_(m-HH))and ice(T_(m-ice)).Here we present two equations that can be used to calculate the relative proportion of NaCl(i.e.,NaCl/[NaCl+CaCl_2],or X_(NaCl))and the total salinity( i.e.,NaC1 + CaC12,wt% )for fluid inclusions with ice as the last melting phase.X_(NaCl)can be calculated from T_(m-HH)using the following equation: y=(a+bx)^(-1/c) where y is X_(NaCl),x is T_(m-HH),a=0.33124402,b=-0.031518028,and c=0.22932736.In the cases where only T_(m-ice)is measured and T_(m-HH)is not known,T_(m-ice)can be used as the maximum possible TIn.nil to calculate the maximum value of X_(NaCl)using the above equation.In these cases,the following equation can be used to calculate the maximum total salinity: y=(a+bx+cx^2)^(-1) where y is salinity,x is T_(m-HH),a=0.057184817,b=0.00078565757,and c=5.7262766E-6.Because the isothems in the field of ice are sub-parallel to the NaCl-CaCl_2 binary side in the H20-NaC1-CaC12 ternary system,the errors in salinity calculation introduced by the above approximation are small(less than 2 wt% ).A Windows program for calculation of X_(NsCl)and salinity is available at: http://uregina.ca/~chiguox.展开更多
Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, ...Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.展开更多
For increasing reaction rate and reducing decomposing temperature,TG-DTA,XRD,SEM and Chemical analysis were used to study the kinetics of mixed rar e earths minerals decomposed by CaO with NaCl-CaCl2. The results show...For increasing reaction rate and reducing decomposing temperature,TG-DTA,XRD,SEM and Chemical analysis were used to study the kinetics of mixed rar e earths minerals decomposed by CaO with NaCl-CaCl2. The results showed that the reaction rate increased with increasing of NaC-CaCl2 addition,CaO addition,an d decomposition temperature. The kinetics of mixed rare earths minerals decompos ed by CaO conformed to 1-2/3X-(1-X) 2/3=kdt mode. The decomposition reaction rate was controlled by two steps,and the activation energy was decreased with addin g of NaCl-CaCl2 melting salt. The micro-pattern of products was loosening and po rous with NaCl-CaCl2 in decomposition system.展开更多
Previous cryogenic Raman spectroscopic analysis of H_2O-NaCl-CaCl_2 solutions has identified the Raman peaks of various hydrates of NaCl and CaCl_2,and established a linear relationship between Raman band intensity of...Previous cryogenic Raman spectroscopic analysis of H_2O-NaCl-CaCl_2 solutions has identified the Raman peaks of various hydrates of NaCl and CaCl_2,and established a linear relationship between Raman band intensity of the hydrates and the composition of the solution（NaCl/（NaCl＋CaCl_2） molar ratio,or X_（NaC1）） using synthetic fluids,which created the opportunity to quantitatively determine the solute composition of aqueous fluid inclusions with cryogenic Raman spectroscopy.This paper aims to test the feasibility of this newly established method with natural fluid inclusions.Twenty-five fluid inclusions in quartz from various occurrences which show a high degree of freezing during the cooling processes were carefully chosen for cryogenic Raman analysis.X_（Na）Cl was calculated using their spectra and an equation established in a previous study.These inclusions were then analyzed with the thermal decrepitation-SEM-EDS method.The X_（NaCl） values estimated from the two methods show a 1：1 correlation,indicating that the new,non-destructive cryogenic Raman spectroscopic analysis method can indeed be used for fluid inclusion compositional study.展开更多
钢铁企业富钾烧结电除尘灰水浸液经脱除重金属杂质后可看作四元水盐体系KCl-NaCl-CaCl2-H2O,从该体系分离出氯化钾,需要首先通过蒸发浓缩及蒸发结晶。为了合理有效的控制蒸发操作过程,今采用静态法实验测定了四元水盐体系KCl-NaCl-CaCl2...钢铁企业富钾烧结电除尘灰水浸液经脱除重金属杂质后可看作四元水盐体系KCl-NaCl-CaCl2-H2O,从该体系分离出氯化钾,需要首先通过蒸发浓缩及蒸发结晶。为了合理有效的控制蒸发操作过程,今采用静态法实验测定了四元水盐体系KCl-NaCl-CaCl2-H2O在KCl浓度为0～3 mol L 1,NaCl浓度为0～2 mol L 1,CaCl2浓度为0～1 mol L 1,温度为303.15～373.15 K的蒸气压,并通过数学线性回归得出了该体系的蒸气压与温度和体系组成的关系式,该关系式的获得有望为实际蒸发操作过程控制提供理论依据。展开更多
GC technology was used to study escaping fluorine in calcined process of mixed rare earth concentrate. The mixed rare earth concentrate and it adding assistant of CaO-NaCl-CaCl2 were calcined at 400～750 ℃ for 30～12...GC technology was used to study escaping fluorine in calcined process of mixed rare earth concentrate. The mixed rare earth concentrate and it adding assistant of CaO-NaCl-CaCl2 were calcined at 400～750 ℃ for 30～120 min, and then total amount of fluorine, exhausting ratio of fluorine, decomposition ratio and the component were determined. The results showed that adding CaO-NaCl-CaCl2 the decomposition ratio was up to 90% at 700 ℃ in 1 h, and the escaping ratio of fluorine decreased from 29.52% to 0.948%. The average inhabitation ratio was 98.39%. This method supplied basis for low energy and clean decomposition of mixed rare earth concentrate.展开更多
基金Project supported by the National Natural Science Foundation of China (50574031)
文摘The influence of NaCl-CaCl2 on thermal decomposition of REPO4（RE： Ce, La, Nd, Th） with CaO was studied. The heat decomposing process of REPO4 was tested with TG-DTA experiments. The results showed that the decomposition temperature of REPO4 with CaO was reduced because of adding NaCl-CaCl2 mixture （NaCl：CaCl2 = 1：1 ）. The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with CaO was studied. The results showed that the decomposition ratio of REPO4with CaO was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.
文摘对恒温热处理后的 NaCl-CaCl_2样品进行差热分析、室温和高温 X 射线粉末照相,并对恒温热处理快速淬火后样品进行了 X 射线衍射结构分析。实验证明了 NaCl-CaCl_2二元体系不存在包晶反应所形成的化合物4NaCl·CaCl_2,属共晶体系,共晶温度为773K,共晶组成为49mol%NaCl、5lmol%CaCl_2;在 NaCl 一侧有固溶体存在;在共晶温度处的固溶度约为18mol%CaCl_2。该二元系的实验测定结果与理论计算结果吻合也很好。
基金Projects Supported by the National Natural Science Fundation of China.
文摘By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been checked.It is.a simple eutectic system with a solid solubility in the sodium chloride side.The eutectic point is at 773K,49 mol% NaCl.The experimental results,especially those of the X-ray diffraction studies have showed that the incongruent compound 4NaCl-CaCl_2 does not exist in the NaCl-CaCl_2 system.
文摘The composition of fluid inclusions in the H_2O-NaCl-CaCl_2 system has been generally graphically estimated using the melting temperatures of hydrohalite(T_(m-HH))and ice(T_(m-ice)).Here we present two equations that can be used to calculate the relative proportion of NaCl(i.e.,NaCl/[NaCl+CaCl_2],or X_(NaCl))and the total salinity( i.e.,NaC1 + CaC12,wt% )for fluid inclusions with ice as the last melting phase.X_(NaCl)can be calculated from T_(m-HH)using the following equation: y=(a+bx)^(-1/c) where y is X_(NaCl),x is T_(m-HH),a=0.33124402,b=-0.031518028,and c=0.22932736.In the cases where only T_(m-ice)is measured and T_(m-HH)is not known,T_(m-ice)can be used as the maximum possible TIn.nil to calculate the maximum value of X_(NaCl)using the above equation.In these cases,the following equation can be used to calculate the maximum total salinity: y=(a+bx+cx^2)^(-1) where y is salinity,x is T_(m-HH),a=0.057184817,b=0.00078565757,and c=5.7262766E-6.Because the isothems in the field of ice are sub-parallel to the NaCl-CaCl_2 binary side in the H20-NaC1-CaC12 ternary system,the errors in salinity calculation introduced by the above approximation are small(less than 2 wt% ).A Windows program for calculation of X_(NsCl)and salinity is available at: http://uregina.ca/~chiguox.
基金supported by an NSERC-Discovery grant(to Chi)in part by the Knowledge Innovation Program of Chinese Academy of Sciences(SIDSSE201302)
文摘Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.
基金Project supported by the National Natural Science Foundation of China (50974042)Scientific Research Special Foundation of Doctor Subject of Chinese Universities (20090042120015)The Fundamental Research Funds for the Central Universities (N090302007)
文摘For increasing reaction rate and reducing decomposing temperature,TG-DTA,XRD,SEM and Chemical analysis were used to study the kinetics of mixed rar e earths minerals decomposed by CaO with NaCl-CaCl2. The results showed that the reaction rate increased with increasing of NaC-CaCl2 addition,CaO addition,an d decomposition temperature. The kinetics of mixed rare earths minerals decompos ed by CaO conformed to 1-2/3X-(1-X) 2/3=kdt mode. The decomposition reaction rate was controlled by two steps,and the activation energy was decreased with addin g of NaCl-CaCl2 melting salt. The micro-pattern of products was loosening and po rous with NaCl-CaCl2 in decomposition system.
文摘Previous cryogenic Raman spectroscopic analysis of H_2O-NaCl-CaCl_2 solutions has identified the Raman peaks of various hydrates of NaCl and CaCl_2,and established a linear relationship between Raman band intensity of the hydrates and the composition of the solution（NaCl/（NaCl＋CaCl_2） molar ratio,or X_（NaC1）） using synthetic fluids,which created the opportunity to quantitatively determine the solute composition of aqueous fluid inclusions with cryogenic Raman spectroscopy.This paper aims to test the feasibility of this newly established method with natural fluid inclusions.Twenty-five fluid inclusions in quartz from various occurrences which show a high degree of freezing during the cooling processes were carefully chosen for cryogenic Raman analysis.X_（Na）Cl was calculated using their spectra and an equation established in a previous study.These inclusions were then analyzed with the thermal decrepitation-SEM-EDS method.The X_（NaCl） values estimated from the two methods show a 1：1 correlation,indicating that the new,non-destructive cryogenic Raman spectroscopic analysis method can indeed be used for fluid inclusion compositional study.
文摘钢铁企业富钾烧结电除尘灰水浸液经脱除重金属杂质后可看作四元水盐体系KCl-NaCl-CaCl2-H2O,从该体系分离出氯化钾,需要首先通过蒸发浓缩及蒸发结晶。为了合理有效的控制蒸发操作过程,今采用静态法实验测定了四元水盐体系KCl-NaCl-CaCl2-H2O在KCl浓度为0～3 mol L 1,NaCl浓度为0～2 mol L 1,CaCl2浓度为0～1 mol L 1,温度为303.15～373.15 K的蒸气压,并通过数学线性回归得出了该体系的蒸气压与温度和体系组成的关系式,该关系式的获得有望为实际蒸发操作过程控制提供理论依据。
基金National Natural Science Foundation of China (50574031)
文摘GC technology was used to study escaping fluorine in calcined process of mixed rare earth concentrate. The mixed rare earth concentrate and it adding assistant of CaO-NaCl-CaCl2 were calcined at 400～750 ℃ for 30～120 min, and then total amount of fluorine, exhausting ratio of fluorine, decomposition ratio and the component were determined. The results showed that adding CaO-NaCl-CaCl2 the decomposition ratio was up to 90% at 700 ℃ in 1 h, and the escaping ratio of fluorine decreased from 29.52% to 0.948%. The average inhabitation ratio was 98.39%. This method supplied basis for low energy and clean decomposition of mixed rare earth concentrate.
