ABSTRACT
The Nanisivik Mne is located on the 73rd parallel in the Canadian Arctic. The mine began commercial production in 1976 and has since produced over 16 million tonnes. The Main Ore Zone stretches for 3.5 km west to east and has an average width of 80 m with a height of 5–20 m. The room and pillar mining method was employed in the Main Ore Zone with approximately 800,000 tonnes remaining in pillars. During 1999, post pillar recovery commenced as an integral part of the annual mine production. Preparation for post pillar recovery was initiated a decade ago with a three phase study that addressed ground stress determinations, ground stability evaluation and a pillar recovery trial The major pillar recovery program commenced after Breakwater Resources acquired the mine in 1996. Tools such as the PIN (pillar index number) system and GMM (ground movement monitors) were developed and implemented to assist in the ground control aspect of post pillar recovery. This paper reviews the post pillar recovery plans as well as the monitoring systems utilized to ensure maximum pillar recovery coupled with maximum safety for the employees.
