Keywords Coal Energy

After exposure by the dragline, the coal is extracted by electric caterpillar-track shovels or rubber-tired, diesel-driven, front-end loaders, and transferred to bottom-dump trucks which haul it to its destination or to railcars for further transport. In open-pit mines, overburden rock normally requires drilling and blasting before it can be removed by shovels or backhoe excavators and loaded into trucks for disposal in dumps or worked-out pits. Open-pits are always worked down in a series of benches, but where the coal seam has been folded or displaced by a fault, open-pit operations may be severely limited.

In the Rocky Mountains and their foothills, coal is mined in the East Kootenay and Peace River coalfields, with mining equipment very similiar to that used in plains strip mines. Rear-dump trucks are used for hauling blasted overburden and coal. The raw coal is taken to coal-processing plants, where it is prepared for export as metallurgical or high-grade steam coal. Preparation involves cleaning the coal - ie, removing inorganic rock material to meet market specifications - and normally is accomplished by processes using differences in specific gravity between coal and rock. Rock material is discarded and the cleaned coal is dried before loading into unit trains for transport. Typically the unit trains are composed of about 100 specially designed "gondola" cars, each of which can hold about 100 t of coal.

Coal Mining
Tofield, Alberta (courtesy Library and Archives Canada/PA-21617).

Underground Mining Methods
Where the limits of surface mining have been reached or the coal is too deeply buried to be extracted in surface workings, underground mining methods are used. Vertical shafts or inclined roadways, the latter known as "slopes" or "drifts," are driven into the coal seam or contiguous rock strata. How the seam is thereafter developed, and which of the several alternative mining techniques is used, depends on the geological "envelope" in which the coal lies and is also determined by detailed considerations of development costs, mine life, operating costs and operational flexibility. There are only 4 underground coal mines in Canada. Two of these underground coal mines are in Cape Breton Island, NS.

In the Cape Breton Island coalfields, which extend out under the Atlantic Ocean to depths of almost 1000 m, the shallower coals are only partially extracted. Coal pillars are left in place at predetermined intervals to support the overlying strata and to avoid potential breaks from the mine workings through to the seabed. When development has reached sufficient depth, a longwall mining technique is used, in which panels are progressively cut, to up to 2 km from the dip slopes. Each panel can yield more than one million tonnes of coal. The coal-cutting machine, a longwall shearer, takes a slice up to one metre wide from the coal face, and a chain conveyor transports the cut coal along the face to a belt conveyor in the main roadway (gate) of the mine.

To protect miners from roof falls, hydraulically operated shields and roadway supports are installed. Holes, drilled into the roof and floor, are connected to pipes to extract methane gas, also called firedamp, which might otherwise constitute an explosion hazard. Water is automatically sprayed wherever coal is being cut or transferred to eliminate risks of dust explosion and to protect miners against pneumoconiosis (black lung disease). This serious disease, which can result from inhalation of fine dust, used to be the scourge of coal-mining operations, but is now virtually stamped out (see OCCUPATIONAL DISEASES).

Industry Resurgence
In western Canada, adverse economic conditions forced the abandonment of older underground mines in the 1950s and early 1960s, but a strong resurgence of the coal industry since the early 1970s has led to numerous new developments, mainly surface mines. Today, the West has 2 underground coal mines and 23 significant surface mines. Coal seams in the Rockies are often up to 20 m thick and, in many places, have gradients as steep as 60°. In these circumstances, a variety of different mining methods, sometimes specially adapted to local conditions, must be used.

One (now closed) operation in the CROWSNEST PASS region of southeastern BC pioneered hydraulic mining for Canadian coal. The thick, pitching seams were cut by a high-pressure jet of water (monitor jet), and the broken coal, after further crushing at the coal face, was transported out of the mine in metal flumes which carried the coal in suspension in water. The water either flowed down the mountainside or was pumped, from beneath the mountain, to a plant which recovered the coal and recycled the cleaned water to the monitor jet. The roof over the worked-out part of the coal seam (the so-called "gob" area) was allowed to cave in.

In mines near Smoky River, Alta, with coal seams 2.5-7 m thick, caterpillar-track-mounted coal cutters (continuous miners) are used for underground room-and-pillar mining. In this system, the coal seam and surrounding rock are cut up into roughly 35 m by 25 m pillars which are removed, and the roof is allowed to collapse into the gob as operations retreat from the outer boundary of the working. During development, the rooms are secured against premature collapse by the insertion of expanding roof bolts. The continuous miner cuts the coal and loads it into electric, rubber-tired shuttle cars which deliver it to the belt conveying system taking it to the surface. This procedure has the flexibility needed for mining in disturbed mountain and foothill terrain but is less productive than longwall retreat mining, in which the panels are driven to the far boundary and coal is cut back toward the entrance.

See MINING WORK FORCE.

Author N. BERKOWITZ, N. DUNCAN and BRUCE STEWART

Links to Other Sites
The Crowsnest Pass Railway Route
This collection of photographs records the history of rail travel through the Crowsnest Past region of British Columbia. A Canadian Museum of Rail Travel website.

The Frank Slide
This website describes probable causes of the Frank Slide. From the CGRG Bibliography of Canadian Geomorphology.

Mineral Deposits of Canada
An overview of the economic and geological contexts of Canada's major mineral deposit types. Scroll down the page for various tables and geological maps of Canada. From Natural Resources Canada.

Canadian Mining Hall of Fame
The Canadian Mining Hall of Fame honours notable leaders, prospectors, and pioneers who made significant contributions to the mining industry in Canada.

Men of the Deeps
Discover the music of Cape Breton's Men of the Deeps, North America’s only coal miner’s choir. Their website features a concert calendar, reviews, discography, and audio clips from their recordings.

Cape Breton Miners' Museum
Dig into the history of Cape Breton coal mining at the Miners' Museum website. Features an extensive glossary, great photographs, and notes about the geological development of Cape Breton's coal field. The acclaimed "Men of the Deeps" choir performs at the museum during the summer season.

Energy Council of Canada
The website for the Energy Council of Canada.

When Coal Was King
The multimedia website “When Coal was King: Coal Mining in Western Canada” explores the history of Alberta’s coal mining industry. Check out the glossary and educational activities. From the Alberta Online Encyclopedia.

Atlas of Alberta Railways
Climb aboard the "Atlas of Alberta Railways" website for a fascinating multimedia tour of Alberta history. This site will take you to a great collection of fascinating maps, old newspaper articles, scenic photographs, charts, graphs, and much more. From the University of Alberta Press.

Towards a Collection of Coal-Mining Songs in Canada
A survey of songs about Canada's coal mines and the miners who work there. Categories include songs about mine disasters or tragedies, union, strike songs, and more. Majority of songs composed by or contributed by Canadian song writers, singers, or collectors. From the “Canadian Journal for Traditional Music.”

Industrial Development of Lethbridge: A Geographer's Interpretation
An account of the industrial development in the City of Lethbridge from a geographical and historical perspective. A paper by Ian MacLachlan, The University of Lethbridge. Click on the link at the bottom of the page for the PDF version of this document.

A History of Mining in Cape Breton
A great information source about the history of coal mining in the Cape Breton region of Nova Scotia. From Library and Archives Canada.

Atlas Coal Mine National Historic Site
Learn about coal mining in the Drumheller Valley at the website for the Atlas Coal Mine National Historic Site.

Sparwood Virtual Museum of Coal Mining
A Explore the history of coal mining in the Elk Valley Crowsnest Pass region, near the communities of Michel-Natal and Sparwood British Columbia. Check out the glossary of mining terms.

Glossary: Coal
A glossary of terms that relate to coal mining. Check the rest of the site for additional information. From the Coal Association of Canada.

Port Morien French Mine Site
A brief history of the "Port Morien French Mine Site", the first commercial coal mine in North America. From the Nova Scotia Museum website.

The Springhill Mine Disaster of 1958: Final Report of the Royal Commission of Inquiry
Read the entire Final Report of the Royal Commission of Inquiry into the Springhill Mine disaster of 1958. Also, check out the additional online resources about coal mining in Nova Scotia. From the website History of Coal Mining in Nova Scotia.