Mineralogical Characterization of Di Linh Bentonite, Vietnam: A Methodological Approach of X-ray Diffraction and Transmission Electron Microscopy
2014 (English)In: Proceedings of 13th International Symposium on Mineral Exploration (ISME-XIII): Toward Sustainable Society with Natural Resources - Frontiers in Earth Resources Technologies and Environmental Conservation / [ed] Noriyoshi Tsuchiya; Mai Trong Nhuan; Thao Hoang-Minh; Tatsu Kuwatani, Hanoi: Vietnam National University Press, Hanoi , 2014, 143-148 p.Conference paper (Refereed)
Vietnam has decided to establish nuclear power as further energy option. In order to develop a Vietnamese reference bentonite as potential barrier in a final repository for high radioactive waste, a detailed mineralogical investigation of Di Linh bentonite (Lam Dong province), lacustrine clay, was carried out by different methods especially transmission electron microscopy (TEM) linked with energy-dispersive X-ray (EDX). From a sample homogenized from 5 tones of the bentonite, mineral formulae of clay particles was calculated The calculation also focuses on randomly interstratifications of two and three members. The fraction <2 μm of Di Linh bentonite is composed mainly by montmorillonite (Ca0.06Mg0.03Na0.09K0.03Al1.39Fe0.25Mg0.26(OH)2 Si3.96Al0.04O10) and regular ordering (R1) illite-smectite interstratifications with K- and charge-deficiency (Ca0.04Mg0.07Na0.18K0.16Al1.76Fe0.08Mg0.16(OH)2Si3.62Al0.38O10). Additionally, Fe-poor kaolinite-smectite-vermiculite interstratifications and trace of Fe-rich chloritesmectite- vermiculite interstatifications were identified. TEM-investigations showed analytical proofs of the sedimentary character of smectite formation in the Di Linh deposit. Parent muscovite was weathered in several steps in two different environments: (i) K-leaching and layer-wise alteration into kaolinite; (ii) further edge- controlled alteration of mica into lathlike montmorillonite particles under dissolution of kaolinite layers from former kaolinite-mica intergrowths. Mineralogical composition of the Di Linh bentonite with mainly montmorillonite and illite-rich illite-smectite interstratifications shows that the Di Linh bentonite can be a suitable barrier candidate in final repositories.
Place, publisher, year, edition, pages
Hanoi: Vietnam National University Press, Hanoi , 2014. 143-148 p.
Bentonite, Transmission electron microscopy, X-ray diffraction, Civil engineering and architecture - Geoengineering and mining engineering
Samhällsbyggnadsteknik och arkitektur - Geoteknik och gruvteknik
Research subject Soil Mechanics
IdentifiersURN: urn:nbn:se:ltu:diva-37416Local ID: b6ef19e5-a4f1-48bb-817d-d2f817451697ISBN: 978-604-62-1540-0OAI: oai:DiVA.org:ltu-37416DiVA: diva2:1010914
International Symposium on Mineral Exploration : 22/09/2014 - 24/09/2014
Godkänd; 2014; 20150212 (svek)2016-10-032016-10-03Bibliographically approved