UBC Theses and Dissertations
A study of selected industrial minerals for water treatment and supplementary cementing materials Entesari, Alireza
A study was conducted on three natural mineral materials referred to as basalt, scoria, and calcined shale. These materials were provided by an industrial mineral producer in British Columbia. The main objectives of this study are, to evaluate the selected materials for treatment of metal contaminated effluents by adsorption, and to assess the possibility of replacing cement with the materials and to evaluate the performance of the cement replaced mortars. In this research study, adsorption tests were conducted to asses the possibility of removing cationic and anionic metal ions from prepared and sampled oil refinery, and mine water effluents. Results of these tests indicate that the calcined shale material was an efficient adsorbent removing more than 99.8% of the copper from the effluent. Basalt material is a natural adsorbent that is highly capable of removing more than 99.9% molybdenum and arsenic ions and performs better than activated carbon. The treated effluents meet the regulatory limits of the Canadian Fisheries Act. The adsorption process when supplements the high density sludge (HDS) treatment, presents a reliable treatment process in removing metal ions in mine water to the regulatory limits. In particular, post treatment should serve to reduce fluctuations in the effluent discharge level. The materials are assessed as natural pozzolans according to ASTM C618 "Standard specifications for coal fly ash and raw or calcined natural pozzolan for use as a mineral admixture in Portland cement concrete". Results indicate that the materials comply with the standard specifications. Naturally calcined shale is a highly desirable natural pozzolan in which the calcination process to enhance the physical properties of the pozzolan occurs naturally requiring no energy consumption. Over time, natural pozzolan mortars gained higher compressive strength than that of fly ash and control mortars, making them suitable for mass concrete applications where early high strength is not required and low heat of hydration is favorable. Further testing is required to evaluate the kinetics of the metal adsorption processes and to assess the possibility of regenerating the adsorbent bed. Additional testing is recommended to evaluate the performance of the metal loaded adsorbents as pozzolans for long term storage. Leaching tests need to be conducted in order to assess the leachability of adsorbed metal ions.
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