Experimental measurements of the graphite C−O equilibrium and CO2 fugacities at high temperature and pressure
Experimental measurements of the graphite C−O equilibrium and CO2 fugacities at high temperature and pressure
复制标题
高温高压下石墨C−O平衡和CO2逸度的实验测量
DOI：
10.1007/bf02688245
复制
发表时间：
1995
影响因子：
3.5
通讯作者：
B. Wood
中科院分区：
文献类型：
--
作者：
D. Frost;B. Wood
用（Ni，Mn）O+Ni金属组成的滑动式氧化还原传感器，在15-30 kbar和1100-1400°C下测定了石墨与C−O流体之间的平衡f0 ~ 2。在每个实验中，从两个方向接近与金属共存的氧化物的平衡组成，收敛到1摩尔% NiO以内。由于在实验的P-T范围内，C-O流体的CO2含量大于90%，因此我们对CO2的测量转化为CO2逸度的测定，其不确定度为±0.1 log单位。GCO平衡的P-T-fo 2平面的这些新测定与Ulmer和Luth（1991）使用纯金属-金属氧化物传感器的主要非可逆测量以及Saxena和Fei（1987）的状态方程非常一致。Redlich-Kwong（MRK）状态方程的修正形式（霍洛威1977;弗劳尔斯1979;克里克和雅各布斯1981）预测GCO平衡时的fo 2值比实验确定的要高。这意味着CO2比MRK预测的更可压缩。
Thefo2of the equilibrium between graphite and C−O fluid has been determined from 15–30 kbar and 1100–1400°C using a sliding redox sensor consisting of (Ni, Mn) O+Ni metal. The equilibrium composition of oxide coexisting with metal was approached from both directions in each experiment with convergence to within 1 mol% NiO. Since, in theP−Trange of the experiments, C−O fluids are >90% CO2our measurements offo2translate into determinations of CO2fugacity with an uncertainty of ±0.1 log units. These new determinations of theP−T−fo2plane of GCO equilibrium are in excellent agreement with the mainly unreversed measurements of Ulmer and Luth (1991) using pure metal-metal oxide sensors and with the equation of state of Saxena and Fei (1987). Modified forms of the Redlich-Kwong (MRK) equation of state (Holloway 1977; Flowers 1979; Kerrick and Jacobs 1981) predict higher values offo2for the GCO equilibrium than determined experimentally. This implies that CO2is more compressible than the MRK predicts.