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Uranium was discovered in 1789 by Martin Klaproth, who named it after the recently discovered planet Uranus. Interestingly, Klaproth also discovered zirconium — another important element in the nuclear field. Uranium is one of the more common heavy elements in nature, 500 times more abundant than gold and about twice as common as tin. It is present in virtually all rocks and soils as well as in rivers and oceans. Traces are found in food and human tissue. Granite, which makes up about 60% of the earth's crust, averages about four parts per million (ppm) uranium, although the concentration is highly variable. Phosphate rock used to produce fertilizer can contain as much as 400 ppm uranium, and some coal deposits contain up to 1,000 ppm. Long used to add colour to glass, ceramics, and porcelain dentures, it is only in the past half century that uranium has become a valuable energy source. Uranium deposits with concentrations of about 1000 ppm and greater of uranium may be considered "ore", that is, they may be economic to mine.
Prospecting, the search for valuable minerals holds a romantic place in the history of Canada. Early discoveries of uranium were made in the traditional method by grizzled prospectors braving the wilderness on foot and canoe. But modern times have led to modern methods. Today, aircraft specially equipped with radiation detectors fly low-level surveys over areas that, based on geological maps, appear promising. Once an area has been identified as having potential, field crews investigate it on the ground using hand-held radiation detectors such as Geiger-Muller counters. Water, soil, and vegetation samples are also collected and analyzed for their uranium content.
Considerable detective work is required to find uranium deposits. For example, if uranium-bearing boulders are discovered, geologists will reconstruct the movement of past glaciers to determine from where they may have come. If uranium deposits are hidden deep underground, geophysical methods such as electrical-resistivity surveys are conducted to find materials like graphite, which are good conductors of electricity and are often associated with uranium deposits. Once the search has been narrowed to a small target area, drill rigs are brought in, often by float-planes, and extract rock cores from the subsurface. Chemical analysis of the samples determines whether uranium is present in economic concentrations and helps define the size and shape of the ore body.
Canada has been a major world producer of uranium since the global demand for this material developed. Today, the only producing area is northern Saskatchewan, although other areas have been active in the past. Canada is the world's leading exporter of uranium and hosts three of the top ten producing mines in the world. To place this into perspective, Canada's production of 11,180 tonnes of uranium oxide (U3O8) in 2007 contained more than twice the energy available from Canada's total annual oil production. Total world production of uranium oxide that year was 48,680 tonnes. Canada is one of the world’s largest producers of natural uranium, providing 20% of total world production from its Saskatchewan mines in 2009.
Great Bear Lake — Northwest Territories
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Pitchblende
Canada's uranium mining industry began in 1931 when prospector Gilbert Labine discovered pitchblende, a uranium-bearing mineral, near the shores of Great Bear Lake in the Northwest Territories. His discovery resulted in the development of a mine at Port Radium, Northwest Territories, in 1932, and a refinery in Port Hope, Ontario, in 1933, both owned and operated by Eldorado Gold Mining Company. The original objective was to produce the rare and precious element, radium, which is found in uranium ore, and was felt to be a miracle cure for cancer. It commanded prices as high as $75,000 per ounce until the bottom fell out of the market in the late 1930s.
During World War II, the demand for uranium took centre stage as the United States and its allies, Britain and Canada, began the Manhattan Project that developed the first nuclear weapon. The Canadian government took over Eldorado and formed a Crown corporation, which was later renamed Eldorado Nuclear Limited, and the Port Radium mine was re-opened. The demand for uranium for weapons production continued in the post-war era. Port Radium produced uranium until the mine was closed in 1960. By the early 1960s, demand began to be driven by the development of nuclear power for the production of electricity.
Ontario has also seen considerable uranium activity. The Bancroft area witnessed radium mining in the 1920s and 1930s, and lived through two uranium booms from 1956 to 1964 and from 1976 to 1982. Faraday, Bicroft, and Madawaska Mines, all abandoned today, produced about 6,700 tonnes of uranium oxide (U3O8) using underground mining methods.
Elliot Lake, Ontario, became a uranium boom-town virtually overnight. In 1954, Denison Mining intersected uranium in exploration drilling, and a brief three years later the first mine was in production. From there, Elliot Lake grew rapidly and soon gained a reputation as the "Uranium Capital" of the world. Two major companies, Denison Mines Ltd. and Rio Algom Ltd., operated 12 mines (Quirke, Panel, Spanish American, Nordic, Lacnor, Milliken, Buckles, Stanleigh, Pronto, Dension, Stanrock, and Can-Met) and their accompanying mills. The ore, with a grade of approximately 0.1 to 0.2% uranium oxide, was mined from a depth of about 170 to 950 metres using underground mining methods.
Elliot Lake, Ontario
As a result of continuing foreign military demand, Canada's uranium mining industry continued to grow until 1959, when more than 12,000 tonnes of uranium oxide were produced, yielding $330 million in export revenue, more than any other mineral. Over the next few years, however, the military demand declined and the number of mines operating in Canada decreased to four. Uranium exploration waned and in 1965, Canada implemented a policy of selling uranium for peaceful purposes only. Due to the decrease in demand, the Canadian government conducted a uranium-stockpiling program until 1974 to support the industry. Thereafter, the uranium industry again experienced growth due to the demand for electricity-generating nuclear reactors.
After three decades as the uranium capital of the world, Elliot Lake bowed to the inevitable fate of all mining centres. Unable to withstand the strong competition from the much higher-grade ore bodies in Saskatchewan and their lower production costs, the Ontario mines were decommissioned in the early to mid-1990s, having produced over 550,000 tonnes of U3O8. In 1996, with the closure of Stanleigh Mine, Saskatchewan became the sole province producing uranium.