Research team applies theory of blasting to mine conditions

Damage to surrounding rock masses caused by development and production blasting in mines is the focus of an investigation by S.P. Singh, associate professor at Laurentian University’s School of Engineering in Sudbury, Ont.

Blasting fractures the rock intentionally, but also causes damage beyond the limits of the planned excavation, Singh said. Major concerns include safety (rock fall) and overbreak (removing more rock than planned).

Extra work in scaling, roof bolting and screening are other factors which also increase costs.

The professor’s blast damage research project attempts to quantify and evaluate all of the various parameters involved in the blasting process and the use of explosives to break rock.

Preliminary research was performed using laboratory-scale models and small charges of explosives. The present phase of the research project attempts to apply laboratory-scale technology to a real rock mass situation. To achieve this transition, a rock mass relatively free of faults and slips is required.

Singh’s investigating team found an ideal rock mass in a Sudbury area quarry owned by Ethier Sand and Gravel. With permission from the owner, Marcel Ethier, the team planned an ambitious extended experiment involving the excavation of some underground workings.

Further arrangements were made with the Ontario division of Inco, Falconbridge, Denison, Comarco Equipment Ltd. and Boyes Explosives of Sudbury for the loan and supply of more than $250,000 worth of specialized equipment and materials.

Armed with this vital equipment and an ideal location, four mining engineering students, faculty and staff spent six weeks late last year preparing the site and making the first blast. Results of this blasting proved promising, and research resumed in late March.

Noranda Technology, a unit of Noranda, recently presented Singh with a $10,000 donation. Substantial funding has also been pledged by Cominco, Rio Algom in Elliot Lake and Inco’s Manitoba division in Thompson.

The project will employ students, allowing them to enhance their engineering skills. The research, Singh said, has also served to establish the long-term potential for an explosives field testing centre to be situated in the Sudbury region.