FUTURE VIEW: A longwall mine will have minimal impact on Fernie’s scenery. —photo courtesy Steve Hovis

Rio Tinto is looking to expand its interests into the profitable Crowsnest Coalfield and add to its metallurgical coal base.

Steve Hovis is a senior project geologist with Kennecott Exploration Inc.—an exploration group owned by Rio Tinto—who spoke at length about the potential for a new underground coal mine in the Elk Valley. While open-pit mines are more common in the Elk Valley, Rio Tinto opted to switch to an underground model as a means of expanding its possibilities. As Hovis explained, in most cases a surface mine is preferable to an underground mine for economic purposes; however, in order to create a sustainable operation, Rio Tinto chose to go below the surface.

The Crowsnest Coalfield just east of Fernie is the target of the initial drilling project. The area has many of the same sequence of coal seams that are being mined by Elk Valley Coal Corporation.

“There’s a lot of coal sitting there,” said Hovis. “And the question is, can it be mined—economically and safely?”

Rio Tinto is willing to explore further to see if the answer is yes.

Two drill holes are planned for the immediate future to determine the feasibility of establishing a mine. If the results are positive, Rio Tinto will move forward with establishing a longwall mine.

A longwall mine utilizes an underground coal mining technique where a long wall of coal is mined in a slice a few metres thick and several hundred metres wide. Longwall mining can provide better resource recovery—80 per cent compared to 60 per cent for room-and-pillar mining—as well as providing a safer underground working environment for the miners. The initial start up costs for a longwall mining operation are understandably high, which is one of the reasons why Rio Tinto is investigating the possibilities thoroughly.

There are many other technical issues to consider once the results from the initial drill testing are completed. The geological structure of the area includes several faults and folds that could hamper the effectiveness of the longwall mine; a change of several degrees of elevation in a seam can greatly increase the costs of the operation. Surface subsidence is also common with longwall mining, which can alter the landscape above the mine, though Hovis expects the impact will be minimal. Whether such occurrences can be anticipated before the operation begins is one of the questions that needs to be answered, said Hovis, but advanced imaging capabilities will aid in providing those answers.