The project was a proposed 6,000 mtpd open pit gold mine located on Graham Island, the northernmost island in the Queen Charlotte Islands group, off the West Coast of Canada. Dr. Robertson was the Project Principal and a lead technical contributor when SRK designed the waste management and water management facilities for the project.
The Queen Charlotte Islands are an environmentally sensitive area. All planning and designs for the project have recognized that the mine must be operated and closed down in an environmentally safe manner. The work involved “state of the art” research and study of acid mine drainage and set new standards for the engineering design of an environmentally safe mine.
- Three-pond impoundment system to provide zero-discharge of mill discharge water in an area with annual precipitation of 2 meters
- Earth and rockfill embankments, ranging in height from 20 to 70 m designed to withstand shaking from a maximum credible earthquake of magnitude 8.6 (Richter scale)
- Groundwater investigation and modelling to estimate groundwater seepage and movements both during operation and after closure of mining
Mine Waste Management System
- Most rapidly oxidizing rock waste deposited below water in tailings impoundment
- Remaining acid generating waste in life of mine temporarily “stockpiled” on undrain seepage collection system and with clay covers
- Finely crushed limestone blended into waste to control acid generation during mining period
- On mine closure, all acid generating rock returned to pit and placed below final flooding level
- Site selection and ranking of potential tailings impoundment sites
- Site investigations and preliminary design reports of tailings impoundment system for environmental impact analysis
- Seismic risk assessment
- Rock waste and tailings geochemical characterization and modelling
Robertson, A. MacG., Baron-Bridges, J.P., and Cowdery, P. (1988) Material Control of Acid Generation for the Cinola Gold Project. In: International Conference on Control of Environmental Problems from Metal Mines, Norway.
Uranium City Resources Inc.
Pit Slope Engineering for Mines