Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
In Björkdalsgruvan the main underground driving method is sub-level caving and a part of this driving method include drifting to get access to the ore and make the sub-level caving possible. To ensure complete safety, a good profile of the drift and to minimalize damage in the surrounding rock there is a method of blasting profiles called stringcharging. There is some hesitancy surrounding the results of the drifting considering of remaining rock in the profile. There are no definite guidelines about how the charging should be executed which leads to the different execution between the shift teams with different results as a consequence. The reasons for these varying results can be many, shifting geology, the drilling, the firing sequence, the amount of explosives and of course the execution of the actual charging. By charging and blasting a number of drifts using three different methods and analyzing the outcome of these should this work help the mine's staff to new guidelines in how the charge should be performed for a good result. After charging, method used is written down as well as the amount of explosives and any deviations. After blasting final contour is photographed and assessed. The number of holes that has been left in the profile has been halved from 2.2 holes per advance to one hole per advance. The number of visible half holes in the profile has increased by 47% from 1.7 to 2.5 per advance.
Place, publisher, year, edition, pages
2016. , 41 p.
Teknik, Gruvdrift, laddning, sprängning, ortdrivning, sprängteknik
IdentifiersURN: urn:nbn:se:ltu:diva-57798Local ID: e6bee564-9220-4bfa-9e46-86597a292396OAI: oai:DiVA.org:ltu-57798DiVA: diva2:1031186
Subject / course
Student thesis, at least 7,5 credits
Mining and Geotechnical Industry, Higher Education Diploma
Validerat; 20150828 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved