%0 Journal Article
%T Transmission X-ray Microscopy¡ªA New Tool in Clay Mineral Floccules Characterization
%A Marek S. £¿bik
%A Yen-Fang Song
%A Ray L. Frost
%A Chun-Chieh Wang
%J Minerals
%D 2012
%I MDPI AG
%R 10.3390/min2040283
%X Effective flocculation and dewatering of mineral processing streams containing clays are microstructure dependent in clay-water systems. Initial clay flocculation is crucial in the design and for the development of a new methodology of gas exploitation. Microstructural engineering of clay aggregates using covalent cations and Keggin macromolecules have been monitored using the new state of the art Transmission X-ray Microscope (TXM) with 60 nm tomography resolution installed in a Taiwanese synchrotron. The 3-D reconstructions from TXM images show complex aggregation structures in montmorillonite aqueous suspensions after treatment with Na +, Ca 2+ and Al 13 Keggin macromolecules. Na-montmorillonite displays elongated, parallel, well-orientated and closed-void cellular networks, 0.5¨C3 ¦Ìm in diameter. After treatment by covalent cations, the coagulated structure displays much smaller, randomly orientated and openly connected cells, 300¨C600 nm in diameter. The average distances measured between montmorillonite sheets was around 450 nm, which is less than half of the cell dimension measured in Na-montmorillonite. The most dramatic structural changes were observed after treatment by Al 13 Keggin; aggregates then became arranged in compacted domains of a 300 nm average diameter composed of thick face-to-face oriented sheets, which forms porous aggregates with larger intra-aggregate open and connected voids.
%K Transmission X-ray Microscope
%K montmorillonite flocculation
%K montmorillonite gel
%K clay microstructure
%U http://www.mdpi.com/2075-163X/2/4/283