Largest underground drilling contract to date was for Assmang’s Black Rock mine operations project in the Northern Cape which was completed with a flawless safety record and uncompromised commitment to quality assurance and environmental project aspects.
The purpose of the drilling contract was twofold; Assmang wanted to prove/verify the thickness of its middling seam because it connects with the manganese-rich 2 seam. Through our core sample drilling the middling seam proved to be on average 25 m from existing hanging wall.
Geomech Africa also provided the geological information for the silo tips and crusher plant infrastructure development. The investigation for the tip silos was combined with proving the middling thickness and entailed drilling vertically upwards into the hanging wall. The investigation for the crusher plant entailed conventional downward drilling to a maximum depth of 25 m.
No challenge too difficult to overcome. The Black Rock geological conditions underground were challenging. The material we had to drill through was exceptionally hard. To compensate for that we experimented with and found the best suited drill bits and lubrications. In combination with areas where the rock was softer, we were able to meet our advancement targets and in actual fact exceed them. We completed the project two days ahead of schedule.
The tender specification required 100% core recovery from the rotary drilling contract which Geomech Africa successfully achieved – from 640 m of drilling in total.