Alberta Innovates – Energy and Environment Solutions (AI-EES), in collaboration with the recently formed Oil Sands Tailings Consortium (OSTC), contracted the Consortium of Oil Sands Tailings Management Consultants (CTMC) to prepare a technology deployment roadmap for “end to end” solutions for oil sands tailings. This report presents the findings and recommendations from Component 1 of the team, charged with gathering available information on oil sands tailings, summarizing the current state of knowledge and practice, and identifying and describing tailings management technologies used in the oil sands and around the world. The other component groups have used the information from this report in their assessment and preparation of the roadmap. .
Component 1 identified 549 technologies through a review of commercial practice in the oil sands, interviews with OSTC and CTMC members, a literature review, discussions with vendors, and a newspaper advertisement. With refinement, these were reduced to 101 unique technologies. We classified the information in two main ways – the stage of development for each technology and its position in the mining life cycle. The former was divided into research, development and commercial, using the specific definitions given in this report. The latter was divided into the following categories: mining, extraction, tailings processing, tailings deposition, reclamation, and water treatment. We further identified technologies that were used com- mercially elsewhere but not in the oil sands (which turn out to be few), and those which were variations or enhancements of the base 101 technologies (the enhancements were mostly chemical aids for tailings processing).
We’ve identified just a few technologies in the mining category that can be used to reduce the amount of fines reporting to tailings. Similarly, there are only a few opportunities in water based extraction to influence tailings behaviour in a meaningful way, but other, non-water based methods may provide an opportunity to avoid creating tailings slurries, if some of the environmental and economic hurdles can be overcome. Most of the technologies considered in this study were in the tailings processing and tailings capping and deposition categories. There were also a number of reclamation and water treatment technologies that can be applied to a variety of tailings situations.
It remains critical that the process affected water chemistry be adjusted or maintained such that it does not adversely impact bitumen recovery, and can be dealt with safely in the reclaimed landscape and made suitable for eventual discharge to the environment (that is, that the total dissolved solids, pH, and chronic and acute toxicity are kept within favourable limits).
To summarize the state of practice for tailings management, we identified eight main tailings schemes, each composed of seven to ten technologies. In all, there are 21 tailings technologies already in commercial use, many mature, some coming on stream just recently (and may be considered pre-commercial) mostly in response to recent changes in regulations. The C4 Team used this framework for a gap analysis, identifying where existing commercial technologies
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could be improved, replaced, or augmented by other technologies to create tailings that better meet tailings management goals. We’ve also made specific conclusions and recommendations regarding several aspects of commercial operations, most notably to revisit the processing of froth tailings to reduce its potential environmental impacts.
To provide a summary of tailings development, we compiled a table of tailings pilots and prototypes conducted over the past 30 years. Many of these pilots have led to commercial implementation. We’ve recommended revisiting the results of the other pilots to see if there are any technologies that should be reconsidered for commercialization, in the light of the current regulations and economic environment.
For the technologies at the research stage, the supporting data varies from excellent to nearly nonexistent. We’ve recommended developing a standard suite of laboratory tests to put research technologies on a common footing, and reviewing the existing information to see what technologies require further testing and which ones might be candidates for pilots. Furthermore, we’ve recommended that AI-EES and the OSTC develop a formal scanning process to seek out and receive new technologies as they are developed, and to embark on their own research and development (R&D) programs over the next 30 years.
We’ve framed our recommendations within the text that are gathered in the final chapter of the report.