Solubility of H2O in rhyolitic melts at low pressures and a new empirical model for mixed H2O-CO2 solubility in rhyolitic melts
Solubility of H2O in rhyolitic melts at low pressures and a new empirical model for mixed H2O-CO2 solubility in rhyolitic melts
复制标题
DOI：
10.1016/j.jvolgeores.2004.09.019
复制
发表时间：
2005-05-01
影响因子：
2.9
通讯作者：
Behrens, H
中科院分区：
文献类型：
--
作者：
Liu, Y;Zhang, YX;Behrens, H
在700-1200 ℃和0.098-25 MPa条件下，进行了H_2O在人工合成的单花岗岩和天然流纹质熔体中溶解度的实验。通过使用具有不同初始H2O含量的起始材料的逆转证明平衡的达到。采用傅里叶变换红外光谱法测定溶解H2O含量。当温度从1000 ℃降低到700 ℃时，H2O的溶解度从0.100增加到0。124重量%在0.098 MPa下，0.99至1.36重量%在11 MPa下，和1.46至2.17重量%压力为25 MPa。在6 MPa下，H2O的溶解度从0.63增加到0.77 wt.%从1200到850摄氏度结合我们的数据与文献中的纯H2O和纯CO2溶解度，混合H2O-CO2溶解度，H2O-H-2气体混合物的H2O溶解度（240测量H2O和59点CO2），我们开发了一个单一的经验模型的纯H2O蒸汽，纯CO2蒸汽，以及混合H2O-CO2蒸汽在metaluminous高硅流纹岩熔体中的溶解度。该模型适用于700-1200 ℃、0-500 MPa的条件，由两个方程组成：H2 Ot =（354.94便士（w））（0.5）+ 9.623P（w）- 1.5223P（w）（1.5））/T + 0.0012439P（w）（1.5）+ P-CO2（-1.084 x 10（-4）P（w））（0.5）- 1.362 x 10（-5）P（w））CO2 = PCO 2（5668 - 55.99P（w））/T + P-CO2（0.4133 P（w）（0.5）+2.041 X 10（-3）P（w）（1.5））其中H2Ot是以重量%计的总溶解H2O含量，CO2含量以质量ppm计，T是以开尔文计的温度，P-w=（XwP）-P-f和P-CO2-（XCO 2 P）-P-f（以MPa计），其中X-w（f）和X-CO2（f）是流体中水和CO2的微粒分数。H2O方程的2 sigma相对不确定度为15%，CO2方程为20%。上述H2O方程也适用于H2O在混合H2O-H-2流体中的溶解度，其中X-H（2）f在100 MPa时< 0.54，X-H（2）f在200 MPa时< 0.49，X-H（2）f在200 MPa时< 0.49，
Experiments of H2O solubility in synthetic haplogranitic and natural rhyolitic melts were conducted at 700-1200 degrees C and 0.098-25 MPa. Attainment of equilibrium was proven by reversals using starting materials with different initial H2O contents. Dissolved H2O contents were determined using Fourier transform infrared spectroscopy. When temperature decreases from 1000 to 700 degrees C, the solubility of H2O increases from 0.100 to 0. 124 wt.% at 0.098 MPa, from 0.99 to 1.36 wt.% at 11 MPa, and from 1.46 to 2.17 wt.% at 25 MPa. At 6 MPa, the solubility of H2O increases from 0.63 to 0.77 wt.% from 1200 to 850 degrees C. Combining our data with those from the literature on pure H2O and pure CO2 solubility, mixed H2O-CO2 solubility, and H2O solubility for H2O-H-2 gas mixture (240 measurements for H2O and 59 points for CO2) we develop a single empirical model for solubility of pure H2O vapor, that of pure CO2 vapor, as well as that of mixed H2O-CO2 vapor in metaluminous high-silica rhyolitic melt. This model applies to the conditions of 700-1200 degrees C and 0-500 MPa, and consists of two equations:H2Ot = (354.94P(w)(0.5) + 9.623P(w) - 1.5223P(w)(1.5)) /T + 0.0012439P(w)(1.5) + P-CO2 (- 1.084 x 10(-4)P(w)(0.5) - 1.362 x 10(-5)P(w))CO2 = PCO2 (5668 - 55.99P(w))/T + P-CO2 (0.4133P(w)(0.5) + 2.041 X 10(-3)P(w)(1.5))where H2Ot is total dissolved H2O content in wt.%, CO2 content is in ppm by mass, and T is temperature in Kelvin, P-w=(XwP)-P-f and P-CO2-(XCO2P)-P-f (in MPa), where X-w(f) and X-CO2(f) are the mote fraction of water and CO2 in the fluid. The 2 sigma relative uncertainty is 15% for the H2O equation, and 20% for the CO2 equation. The above H2O equation also applies to H2O solubility in mixed H2O-H-2 fluid for X-H(2)f < 0.54 at 100 MPa, for X-H(2)f < 0.49 at 200 MPa, and X-H(2)f