NEWS 2008

Posted April 21, 2008

Event April 30, 2008

Cross Canada Lecture Tour - Alternative Disposal Techniques for Reactive Mine Wastes to Better Control Environmental Impacts

Dr. Michel Aubertin, École Polytechnique de Montréal

Many closure plans for waste disposal sites now involve the construction of a layered cover system. Among the available systems, a cover with capillary barrier effects (CCBE) is often selected as this technique can provide an advantageous alternative to other types of covers that mainly rely on materials having a low ksat value (which is sometimes difficult to attain in situ). Under a wet climate, a CCBE is particularly well suited to act as a gas barrier (for CO2 and O2) due to a fine-grained material layer that can remain nearly saturated at all time. In a relatively dry climate, a CCBE is typically employed to create a Store, Divert, and Release (SDR) system that may prevent water infiltration into the underlying waste. Recent work has also shown that SDR covers can be used in specific situations in a relatively humid climate, particularly when the diversion capacity along the sloping layers can be maximized to meet the site geometry requirements. Designing a CCBE is a progressive process that typically requires laboratory and field experiments combined with numerical simulations to assess the moisture distribution in the unsaturated materials (and sometimes the gas flux) in the system. This presentation will highlight some of the more recent advances made in this area, based on several applied research projects in which the lecturer (and collaborators) have been involved. The main cases will include covers constructed on reactive tailings impoundments, waste rock piles, and other disposal areas. After a brief review of the fundamental principles governing the behavior of CCBEs, emphasis will be placed on a description of the field investigation and modeling work that has lead to the construction of large scale covers. Monitoring the response of cover systems will also be discussed in the presentation.

Location: Woodvale Community Facility, Tournament Room, Millwoods Golf Course, 4540 - 50 Street
Time: 6:30 pm, presentation starts at 7:00 pm
Date: Wednesday, April 30, 2008
Cost: Students: $20, GSE Members: $35, Non-members: $40
Please confirm attendance by 5:00 pm, Monday February 13, 2008
by emailing sean.birch@amec.com