Accelerated Dewatering and Drying Treatment of Oil Sands Tailings by Electrical Resonant Auto-Transformer

  • Author / Creator
    Hande, Aharnish Bhojaraj
  • Canada has world’s third largest oil reserves in the form of oil sands and 20% of those are easily accessible by surface mining. The hot water bitumen extraction process has been used since 1967 and the process produces vast amount of tailings which are stored in ponds. Tailings ponds pose a grave challenge towards sustainable development of Alberta’s mined oil sands. For every barrel of bitumen produced, nearly 15 barrels of tailings including 2 barrels of Mature Fine Tailings (MFT) are generated. Though about 7 barrels of process water is recycled, the rest of the tailings pose complex challenge to faster reclamation. The fine non-settling particles in the tailings are mainly sub-micron size clay particles with repulsive charges. Aggregating these fine suspended particles together holds a key to tailings sedimentation problem. It has been observed that settling of fine particles can be achieved by high electric field treatment by newly developed electrical Near-field Resonant Auto-Transformer (NRAT) system. The NRAT system can produce alternating electric field in order of 1 MV/m for a resonant frequency of about 250 kHz. The voltage and current are out of phase and very little energy is consumed with rest stored back in the system. It was observed that high electric field and field gradient can treat fine tailings in few hours compared to couple of years of gravity treatment. The decanted water can be recycled back while the thickened tailings can be further dielectrically heated with the same NRAT system and dried out. Thus, NRAT system seems to offer a complete solution to tailings problem. We propose to demonstrate usefulness of NRAT system as a cost effective, energy efficient and a safe way for complete treatment of tailings.

  • Subjects / Keywords
  • Graduation date
    Fall 2014
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • 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.