Authors: Wenda Zhou
Addresses: School of Geosciences, China University of Geosciences, Wuhan 430074, China
Abstract: Traditional disaggregation methods for mineral separation of sedimentary rocks are not appropriate for shales with complex mineralogy and grain sizes. In this study, we improved the ultrasonic disaggregation and stepwise separation method for minerals in shales, and applied it to analyse shale samples from the Silurian Longmaxi Formation of the Sichuan Basin, China. The Longmaxi Formation shales are mainly composed of clay minerals, quartz, calcite, dolomite, albite, and K-feldspar, and are cemented by SiO2. This method processes shale samples as ultrasonic disaggregation followed by stepwise separation of minerals using gravitational deposition and centrifugation. Field emission scanning electron microscope (FE-SEM) images were obtained for different components of this ultrasonic disaggregation and stepwise separation method. Information obtained by this method can also be used to quantify the hydrodynamic forces acting on the Longmaxi Formation sediments during the syngenetic stage. [Received: October 25, 2018; Accepted: November 21, 2018]
Keywords: disaggregation; shale minerals; ultrasonication; mineral grain size; critical incipient velocity.
International Journal of Oil, Gas and Coal Technology, 2020 Vol.24 No.3, pp.415 - 425
Received: 25 Oct 2018
Accepted: 21 Nov 2018
Published online: 19 Apr 2020 *