Arsenopyrite oxidative dissolution in NaCl solution at high-temperature and high-pressure conditions: kinetics, pathways, dissolution mechanism and geological implications
Arsenopyrite oxidative dissolution in NaCl solution at high-temperature and high-pressure conditions: kinetics, pathways, dissolution mechanism and geological implications
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高温高压条件下毒砂在氯化钠溶液中的氧化溶解：动力学、途径、溶解机制和地质意义
DOI：
10.1007/s00410-022-01929-2
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发表时间：
2022-06
影响因子：
3.5
通讯作者：
Heping Li
中科院分区：
文献类型：
--
作者：
Qingyou Liu;Kai Zheng;Shuai Wang;Luying Wang;Sen Lin;Heping Li
毒砂(FeAsS)是海底块状硫化物矿床的硫化物矿物之一。氯化钠的存在和高温高压地质条件严重影响毒砂风化过程。然而，电化学氧化溶解从来没有在海底被考虑过，尽管它已经被证明在陆地沉积物中显著增加溶解。本文采用现场电化学技术和表面分析技术，研究了在280~360℃、12.0~20.0 Mpa的压力范围内，不同浓度的氯化钠溶液中毒砂的氧化溶解行为。在初始阶段，毒砂被氧化成S0、As(III)和Fe(II)。S0和As(III)最终转化为SO42−和AsO43−并进入溶液。Fe(II)被转化为α-FeOOH、γ-FeOOH和Fe2O_3作为钝化膜。Cl-−离子的存在促进了毒砂的氧化溶解，但不改变其氧化机理。更高的温度或更高的压力通过促进电荷迁移和离子扩散来促进毒砂的氧化溶解。在实验高温高压条件下，毒砂的氧化溶解速率常数为8.0×10-5moL∙m−2∙S−1。这项工作拓展了对Fe、As和S地球化学旋回的认识，为海底热液条件下毒砂风化形成次生矿物提供了实验依据。
Arsenopyrite (FeAsS) is one of the sulfide minerals of seafloor massive sulfide deposits. The presence of sodium chloride and high-temperature and high-pressure (HTHP) geological conditions seriously affect the process of arsenopyrite weathering. However, electrochemical oxidative dissolution has never been considered in the context of seafloors, though it has already been shown to increase dissolution significantly in terrestrial deposits. In this work, in situ electrochemical techniques and surface analysis were used to investigate the behaviors of oxidative arsenopyrite dissolution in different concentrations of NaCl at temperatures ranging from 280 to 360 °C and pressures ranging from 12.0 to 20.0 MPa. In the initial stage, arsenopyrite was oxidized to S0, As(III), and Fe(II). The S0 and As(III) were ultimately converted into SO42− and AsO43− and entered the solution. The Fe(II) was converted into α-FeOOH, γ-FeOOH, and Fe2O3 as a passivation film. The presence of Cl− ions promoted the oxidative dissolution of arsenopyrite without changing its oxidation mechanism. Higher temperatures or greater pressures promoted the oxidative dissolution of arsenopyrite by enhancing charge migration and ion diffusion. Under the experimental HTHP conditions, the oxidative arsenopyrite dissolution rate constant was 8.0 × 10–5 mol∙m−2∙s−1. This work expands the understanding of the geochemical cycles of Fe, As and S and provides an experimental basis for the formation of secondary minerals from arsenopyrite weathering under the hydrothermal solution conditions of the seafloor.
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DOI：
10.1016/j.scitotenv.2016.05.143
发表时间：
2016-10
期刊：
The Science of the total environment
影响因子：
--
作者：
Hugo Ramírez-Aldaba;O. P. Valles;J. Vazquez‐Arenas;J. Rojas-Contreras;D. Valdez-Pérez;E. Ruiz-Baca
通讯作者：
Hugo Ramírez-Aldaba;O. P. Valles;J. Vazquez‐Arenas;J. Rojas-Contreras;D. Valdez-Pérez;E. Ruiz-Baca
影响因子：
8.3
作者：
Kwon, Sang-Koo;Shinoda, Kozo;Waseda, Yoshio
通讯作者：
Waseda, Yoshio
DOI：
10.1007/bf03402923
发表时间：
1991-02
期刊：
Mining, Metallurgy & Exploration
影响因子：
--
作者：
V. M. Sánchez;J. Hiskey
通讯作者：
V. M. Sánchez;J. Hiskey
影响因子：
1.6
作者：
N. Boucherit;A. H. Goff;S. Joiret
通讯作者：
N. Boucherit;A. H. Goff;S. Joiret
影响因子：
11.4
作者：
C. Neil;Y. Je;rey Yang;D. Schupp;Young-Shin Jun
通讯作者：
C. Neil;Y. Je;rey Yang;D. Schupp;Young-Shin Jun