کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5782983 1637527 2016 49 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of etch pit development on the surface area and dissolution kinetics of the orthoclase (001) surface
ترجمه فارسی عنوان
تأثیر توسعه بتنی اچ در سطح و سینتیک انحلال سطح اوروکلاز (001)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
چکیده انگلیسی
The (001) orthoclase surface was dissolved at 180 °C and at far from equilibrium conditions with an alkaline solution (pH180 °C = 9) in a titanium open flow reactor. Vertical scanning interferometer (VSI) and atomic force microscope (AFM) surface monitoring were periodically used during the reaction process in order to quantify the surface topography evolution. The dissolution of the (001) orthoclase face occurs with the formation of diamond shape etch pits. Diamond pit diagonals are parallel to the [100] and [010] axes, and the pit walls are parallel to (6 5 6), 65¯6, (6¯511) and 6¯5¯11 planes. The etch pit size and global surface retreat of the (001) surface were found to increase linearly with time. Based on statistical treatments of etch pit development monitoring by AFM, we designed a numerical model aimed at reproducing and quantifying the total surface evolution. Numerical results show that the stabilization of etch pits doubles the calculated dissolution rate, partly due to the intrinsically higher reactivity of pit walls, consistent with a dissolution process in line with the periodic bond chain (PBC) theory. In addition, normalizing the dissolution rate by the initial surface area of the (001) orthoclase surface induces a 20% overestimation of the calculated dissolution rate, while the total surface area of the dissolving face reaches a steady state after a few days of reaction. Additional simulations conducted to assess the impact of defect parameters revealed a weak dependence of the dissolution rate on dislocation density, consistent with previous experimental observations. Overall, the combined effect of the various defect parameters does not affect the dissolution rate by more than an order of magnitude, and probably contributes to a moderate extent to the dispersion of mineral dissolution rate data reported in the literature.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Geology - Volume 447, 30 December 2016, Pages 79-92
نویسندگان
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