Abstract
This workshop will present the results of a 4-year project sponsored by Natural Resources Canada, Newmont Corporation, and Ministry of Economics and Innovation of Quebec. This multi-phase project aims at developing an explosive-free method for hard rock breakage using soundless chemical demolition agents (SCDA) or expansive cement. The workshop will begin with an overview of different explosive-free methods while highlighting the merits of SCDA for potential application in underground construction. Phase 1 is concerned with small-scale laboratory tests for SCDA pressure estimation and performance evaluation in various host conditions from steel cylinder to hard rock under uniaxial loading and varying ambient temperatures. The effect of subzero temperature on the SCDA performance is examined on granite cubes. Phase 2 encompasses large-scale tests of 1 m x 1 m panels from concrete and granite. These were carried out to examine the SCDA performance for rock fragmentation under high biaxial confinement. Numerical modeling used to design SCDA fragmentation patterns is explained. In Phase 3, which focuses on field work, a simple and practical method is developed to estimate mining-induced face stresses using rock core deformation analysis. This was used to help design SCDA borehole pattern at a mining face. The rock tensile strength, being a key parameter in fragmentation, is quantified with a new direct tension test apparatus. Field tests took place at two underground mines Hoyle Pond and Éléonore of Newmont. They included boulder fragmentation, slashing of intersections, and drift face advance. Future research/technology directions are discussed.
Short Course Objectives:
- Transfer knowledge and experience gained from a 4-year research/technology project to mining professionals, academia, and entrepreneurs
- Promote awareness of the potential use of expansive cements for hard rock breakage in underground mines as environmentally friendly explosive-free tool
- Seek the formation of an interest group for future meetings at CIM conventions
Target Audience:
Mine operators, mining contractors and researchers.