Effects of Surface Contamination and Water Chemistry on the Behaviors of Illite, Kaolinite and Montmorillonite in Organic and Aqueous Media

• Author / Creator

  Pourmohammadbagher, Amin

• Clays, due to their specific surface area and electrical charge density, are among the most active minerals in aquifers, oil and gas reservoirs, and tailings ponds. Clays, in tailings, are a significant ongoing environmental concern in the mining and oil sands production industries and clay rehabilitation following contamination poses challenges episodically. Important problems, such as limited oil recovery during petroleum exploration, involve the interaction of process fluids with minerals, which constitute reservoir pore walls. Detailed understanding of the fundamentals of clay behaviors contributes to better environmental impact mitigation strategies, to the development of production processes for heavy oils and bitumen with lower environmental impacts, to the treatment of tailings from mined bitumen, and to the mitigation of impacts from oil spills in natural environments. Probes, such as solution calorimetry are sensitive to species transfer to and from clay surfaces. Outcomes can be interpreted unambiguously, when these data are supplemented with TGA and SEM measurements. Systematic calorimetric measurements provide a framework for parsing the synergistic and antagonistic impacts of trace (i.e., ppm level) components on the surface compositions of clays in diverse natural and process environments. In this study, the effects of clay surface contamination, solvent contamination, and the effects of water chemistry (temperature, pH, salinity) on the enthalpy of solution of kaolinite, illite and montmorillonite clays in toluene, n-heptane, pyridine and deionized water were investigated. Clay contamination included pre-saturation of clays with water, organic liquids, and asphaltenes. Solvent contamination included addition of trace water to organic liquids and trace organic liquids to water. A quantitative mass and energy balance modeling framework was developed for interpreting the enthalpy of solution outcomes that isolates terms for solvents and trace contaminant sorption/desorption and surface energy effects. Mechanistic and quantitative insights underlying the surface properties of clay dispersions in tailings ponds, and the behaviors of these clays in diverse industrial and natural environments are discussed.

• Subjects / Keywords

  • Tailings
  • Water chemistry
  • Clay
  • Organic contamination

• Graduation date

  Spring 2016

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3KD1QR06

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.