Redox control and measurement in low-temperature (< 450 degrees C) hydrothermal experiments

doi:10.2138/am-2021-7687

CORC > 深海科学与工程研究所 > 中国科学院深海科学与工程研究所 > 深海科学研究部 > 深海极端环境模拟研究实验室

	Redox control and measurement in low-temperature (< 450 degrees C) hydrothermal experiments
	Fang, Jing 1,2; Chou, I-Ming 1
刊名	AMERICAN MINERALOGIST
	2021-08-01
卷号	106 期号:8 页码:1333-1340
关键词	Redox buffer and control techniques hydrothermal experiments redox reactions hydrogen fugacity sensor fused silica capillary
ISSN号	0003-004X
DOI	10.2138/am-2021-7687
英文摘要	Redox control in hydrothermal experiments is routinely achieved through double-capsule and Shaw membrane techniques. These techniques control oxygen fugacity (f(O2)) by imposing a defined hydrogen fugacity (f(H2)) on a studied sample enclosed, together with H2O, in a hydrogen membrane capsule made of Pt or Ag-Pd alloys. However, due to the low permeability of these membranes to H-2 at low temperatures (T), these techniques do not work efficiently below 450 degrees C. Here, we tested fused silica as a new hydrogen membrane and successfully applied it to monitor and control the redox states of studied samples at T down to 200 degrees C in hydrothermal experiments. Our results showed that 3, 8, 16, 36, 96, and 216 h are sufficient for a fused silica capillary capsule (FSCC) to reach osmotic equilibrium with the externally imposed 1 bar of H-2 at 350, 300, 250, 200, 150, and 100 degrees C, respectively, and H-2 pressures inside a FSCC was very close to the externally imposed values after osmotic equilibrium. By using FSCC as a hydrogen fugacity sensor, equilibrium H-2 pressures for Ni-NiO-H2O and Co-CoO-H2O redox buffer assemblages at 250-400 degrees C and 1000 bar total pressure were measured. The equilibrated f(O2) calculated are consistent with those derived from previous literature. Besides, FSCC can be used as a sample container, where fH(2) and f(O2) of enclosed samples can be continuously controlled. Furthermore, FSCC is an ideal container for sulfur-bearing samples, and its transparency allows spectroscopic analyses of the sample. Our work extended the low-T limit of previously well-developed redox control techniques and may open up a new research avenue in low-T hydrothermal experiments.
资助项目	Key Frontier Science Program of Chinese Academy of Sciences[QYZDY-SSW-DQC008] ; (Chinese) National Natural Science Foundation[41973055]
WOS关键词	ELEVATED-TEMPERATURES ; PRESSURE-VESSELS ; OXYGEN FUGACITY ; WATER-VAPOR ; HYDROGEN ; FRACTIONATION ; CALIBRATION ; SOLUBILITY ; STABILITY ; TRANSPORT
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	MINERALOGICAL SOC AMER
WOS记录号	WOS:000679806000011
资助机构	Key Frontier Science Program of Chinese Academy of Sciences ; (Chinese) National Natural Science Foundation
内容类型	期刊论文
源URL	[http://ir.idsse.ac.cn/handle/183446/8801]
专题	深海科学研究部_深海极端环境模拟研究实验室
通讯作者	Chou, I-Ming
作者单位	1.Chinese Acad Sci, Inst Deep Sea Sci & Engn, CAS Key Lab Expt Study Deep Sea Extreme Condit, Sanya 572000, Hainan, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100871, Peoples R China
推荐引用方式 GB/T 7714	Fang, Jing,Chou, I-Ming. Redox control and measurement in low-temperature (< 450 degrees C) hydrothermal experiments[J]. AMERICAN MINERALOGIST,2021,106(8):1333-1340.
APA	Fang, Jing,&Chou, I-Ming.(2021).Redox control and measurement in low-temperature (< 450 degrees C) hydrothermal experiments.AMERICAN MINERALOGIST,106(8),1333-1340.
MLA	Fang, Jing,et al."Redox control and measurement in low-temperature (< 450 degrees C) hydrothermal experiments".AMERICAN MINERALOGIST 106.8(2021):1333-1340.