KCB was commissioned by the Mine Environment Neutral Drainage (MEND) Program to complete a study to examine and compare alternatives to conventional slurry for the management of tailings (e.g., thickened, paste and filtered tailings). Tailings dewatering process technologies that are currently used in Canada and other jurisdictions with similar climatic conditions were examined. The strengths, limitations, and physical and environmental risks of these alternative technologies were compared to those of conventional slurry. Strengths, limitations and physical and chemical risks were considered across the entire life cycle of tailings facilities, from design and construction through to long-term post-closure.

The study applied the following approach:

1. Conduct a survey to identify the current state-of-practice, and projects that use alternative technologies in Canada.
2. Evaluate the alternatives, comparing tailings management technologies and costs using the information obtained in 1), along with case study information provided by select Canadian and international mine sites.
3. Review advantages and disadvantages of the technologies, assess applicability to Canadian mines, and identify knowledge gaps.

This report presents a snapshot of the current state-of-practice in the Canadian mining industry. It looks at the technologies used to dewater tailings, how tailings are placed and managed, and evaluates their relative efficacy in addressing physical and geochemical risks. The reader will gain an understanding of the strengths and limitations of tailings dewatering technologies, deposition practices, and how these choices apply to specific sites and mining projects compared to conventional practices. The report should help guide which technologies and strategies should be considered for a project, taking into account site conditions, project constraints (e.g. production schedule), tailings’ physical properties (e.g. grain-size, and plasticity), and geochemical properties (e.g. the potential for tailings to generate metal leaching and/or acid rock drainage).

Knowledge gaps and recommendations for further work were outlined, and fell into four categories; costs, closure, other technologies and geochemistry.

The report can be downloaded from the MEND-NEDEM website.

Please take the opportunity to visit the MEND-NEDEM web site: http://www.mend-nedem.org