کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10676960 1011864 2011 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media
چکیده انگلیسی
Aqueous dissolution of a synthetic chloride-containing Mg2+-Al3+ layered double hydroxide was studied at 298 K as a function of pH. Mild acidification (final pH 9 -5) results in incongruent dissolution of Mg2+, exclusively. Formation of an amorphous Al(OH)3 passive layer prevents further Mg2+ leaching, thus dissolved Mg2+ amounts for only 20% of the solid. At lower pH values, massive dissolution readily takes place in a congruent fashion. Congruent dissolution profiles are accounted for by a contracting volume kinetic law. The pH dependence of the observed rate constant shows that the kinetic order on proton concentration is 0.41, indicating that dissolution is surface controlled. The implications of these findings are discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Clay Science - Volume 51, Issue 3, February 2011, Pages 366-369
نویسندگان
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