Size reduction represents one of the most energy-intensive and costly processes in the extraction of valuable minerals and rocks. Drilling and blasting, being the first operation in the size reduction chain, may have a significant downstream effect, influencing mine economics. This thesis investigates effects of blasting on subsequent size reduction operations.
A series of small scale blasts have been conducted, and the fragments have been screened, drop weight tested, crushed and their Bond Work Index and breakage parameters have been determined. The process was repeated for 3 different types of granite blocks (Stanstead, Laurentian, and Barre granite) using samples not blasted previously and samples blasted with three different powder factors (0.391, 0.782, and 1.173kg/m3). As well, four types of different charge methods with the same powder factor were used to investigate the influence of blasting energy distribution on grindability in the case of Barre granite. Subsequently, stress wave collision blasting and the effect of delay timing were tested under the same powder factor conditions.
Generally, powder factor resulted in the most significant changes in the breakage parameters as well as fragmentation. The Bond Work Index showed a small decrease as a function of powder factor, which can be considered to be material dependent.
There is indication that distribution of charge resulted in better grindability while fragmentation seems to be similar in both cases and better than when air decking was used. The results from Barre granite showed clearly that stemming affected fragmentation by producing finer fragments. / Thesis (Master, Mining Engineering) -- Queen's University, 2010-04-23 12:49:29.244
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/5571 |
| Date | 26 April 2010 |
| Creators | Kim, Seok Joon |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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