Aniseh Dadashi, PhD Candidate, University of Alberta, presents her talk "Developing Appropriate Commingled Mixtures of Tailings and Waste Rock and Assessment of the Physical and Chemical Stability of the Material".
Abstract: Conventional practice for the disposal of surface mine wastes has resulted in serious geo-environmental issues. Tailings are the by-products of mineral extraction for almost all mining operations, usually transported hydraulically as slurry and stored behind dams. These dams, which are often constructed from a coarser fraction of the tailings materials, can cause serious problems, such as the poor stability of the tailings impoundments and difficulty in land reclamation. Also, tailings containing sulfide minerals are prone to oxidation and acid rock drainage (ARD) generation upon exposure to oxygen and water. The second waste stream of surface mining operations is the waste rock, which is conventionally hauled to waste dumps. These dumps cause geochemical stability problems and are prone to ARD generation because of their porous structure, allowing oxygen and water to flow through them.
The reoccurrence of the issues mentioned above has encouraged the industry to seek an alternative approach to segregated disposal methods in an attempt to minimize and, if possible, avoid them. To that end, an engineered commingled mixture of waste rock and tailings is proposed to be deposited in self-supporting dry stacks. The commingled mixtures could address the conventional disposal drawbacks by benefiting from both waste streams' desirable properties. This research investigates the physical and chemical characteristics of the mixture, which depend on the properties of its constituent materials and their mixture ratio. In this study, the geotechnical and geochemical properties of the material with several different mixture ratios are investigated using column permeability tests and computerized axial tomography (CAT) scan imaging. This research aims to better understand and predict the commingled material's performance.
Speaker Bio: Aniseh is a PhD Candidate under the supervision of Dr. G. Ward Wilson. She is working on the physical and chemical characteristics of commingled tailings and waste rock mixtures. Before joining the University of Alberta, Aniseh completed her Master's degree in Geotechnical engineering at the California State University of Fullerton. She also holds a bachelor’s degree in architectural engineering from Shomal University in Iran.
1 окт 2023
