Nahanni Construction Ltd. undertook the Giant Mine Early Works Backfill Project in Yellowknife, NT. The project involved underground mine backfill using a non-segregating paste material manufactured on-site. Nahanni developed and implemented a quality control program to ensure the paste material met specifications and was delivered to the intended backfill locations within the mine. This work required a strong understanding of historical mine structures using lidar/3d diagram mine mapping interpretation and precision drilling to get paste to the right locations within the underground stooping.

The paste design, comprised of processed tailings, water, binder, and chemical additives, was completed by Nahanni. In total 116,000 cubic meters of paste material were delivered from the surface to the underground during the 2022 backfill program.

Fast facts:

  • The project involved 232 employees, including rotations.
  • The project accumulated 345,600 man-hours.
  • Nahanni planned and managed all logistics for the project, including labor, material, and supply delivery.

Challenges and how Nahanni Helped:

  • Giant Mine is a site of known contaminated tailings, water, and hazardous materials such as arsenic trioxide dust and asbestos. Nahanni implemented dust control measures, appropriate personal protective equipment (PPE) and associated training and monitoring programs, and careful handling of contaminated water to protect the crew and local environment
  • The site is complex including surface open pits, historical infrastructure, and underground development. Nahanni provided survey work using drones, lidar scans and cavity monitoring survey (CMS).