The steeply dipping vein orebody of Bousquet 2 mine is extracted by sublevel open stope method. The presence of structural discontinuities, high induced stress distribution, and narrow stope widths are major factors which can seriously affect ore dilution. Therefore, strict ore dilution control is necessary in order to keep the mine competitive. The thesis describes the selective mining method adapted to this type of orebody, and subsequent measures taken to minimize ore dilution. For this study, the locations of stress relaxation are taken as failures zones. Therefore, these zones are more important since they are subjected to very low stresses which can provoke rock block sliding or local wall caving (tension failure). Tracing the zone of tensile stress in the stope wall gives reasonable prediction of dilution and permits to calibrate the numerical model using the field data obtained from the cavity Monitoring System (CMS). Stope mining is made in several cuts according to the width of the ore zone. For an improved recovery, some stopes are mined using primary and secondary stoping. Blasthole pattern and mining sequences are closely linked to the ore zone configuration. The main causes of ore dilution are summarized. They are a combination of several factors such as ground conditions, blasting damage, state of stresses around the stope, and stope design. In order to minimize ore dilution from hanging-wall and foot-wall, cable support is installed. Numerical modelling is carried out for a typical cable bolt pattern. The results of modelling have demonstrated that the cable bolts were necessary to control hanging wall caving. This is accompanied by a reduction of ore dilution. Consequently the study has shown the effectiveness of cables bolt as pre-support of the schistose walls in Bousquet sublevel stoping environment.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20903 |
| Date | January 1998 |
| Creators | Diakité, Oumar. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Mining and Metallurgical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001641239, proquestno: MQ50602, Theses scanned by UMI/ProQuest. |
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