Difficult mining conditions in 153 Orebody at a depth of 4600 ft

2009

Zahra Hosseini, Denis O'Donnell,

VALE Inco’s Coleman Mine 153 Orebody is a narrow vein deposit with a dip that varies from 30 to 70 degrees. The primary mining method, in the 153 Orebody is mechanized cut-and-fill. The ore body is divided into 6 levels. This paper will further examine the challenges related to mining in the 4550 level at a depth of 4600ft. The 4550 level is currently being mined at cut 13, leaving a 40 ft crown pillar between this level and the 4400 level above it. Significant factors such as: the condition of the crown pillar, the orebody’s dip change at this level, induced mining stresses, and geological structures have all combined to introduce high seismicity and rockbursts in the 4550 level between blocks 2 and 3. The result is less than ideal mining conditions. To begin, this paper will study the geological structures and stability analysis of the 4550 level and then discuss the studies done and measures taken to control these difficult mining conditions in order to extract the high-grade ore in a safe mining environment.