McClean Lake mine
Encyclopedia
The McClean Lake mine is a uranium
mine and milling operation located west of Wollaston Lake
, about 700 kilometres north of Saskatoon
, in the Athabasca Basin
region of Saskatchewan, Canada. The McClean ore body was discovered in 1979, followed by the discovery of the JEB ore body in 1982. From 1985 to 1990, a cluster of deposits named Sue A, Sue B and Sue C were discovered.
Production from the JEB and Sue C open pits commenced in 1999. Upon depletion, the JEB pit was converted to a Tailings Management Facility (TMF). The Sue C pit will be converted to a TMF for the disposal of waste from the McLean Lake and Cigar Lake
operations. Production from the Sue A mine and development of the Sue E mine, commenced in mid 2005.
After the tailings from the milling operations and waste rock from the mining operations are chemically treated to precipitate arsenic
and nickel
they are pumped into the TMF. There they form a consolidated mass of much lower permeability than the surrounding sandstone
. As a result the groundwater
flow is diverted around the tailings. By these means the water quality in adjacent Fox and Pat Lakes is expected to be maintained within Saskatchewan Surface Water Quality Objectives over the long term (10,000 years). This expectation has to be confirmed by monitoring subject to oversight by the CNSC.
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
mine and milling operation located west of Wollaston Lake
Wollaston Lake
Wollaston Lake is located in northeastern Saskatchewan, Canada. With a surface area of 2286 km² , it is the largest lake in the world that drains naturally in two directions...
, about 700 kilometres north of Saskatoon
Saskatoon
Saskatoon is a city in central Saskatchewan, Canada, on the South Saskatchewan River. Residents of the city of Saskatoon are called Saskatonians. The city is surrounded by the Rural Municipality of Corman Park No. 344....
, in the Athabasca Basin
Athabasca Basin
This article is about the uranium mining region near Lake Athabasca. Not to be confused with the drainage basin of the Athabasca River.The Athabasca Basin is a region of Northern Saskatchewan and Alberta Canada that is best known as the world's leading source of high grade uranium...
region of Saskatchewan, Canada. The McClean ore body was discovered in 1979, followed by the discovery of the JEB ore body in 1982. From 1985 to 1990, a cluster of deposits named Sue A, Sue B and Sue C were discovered.
Production from the JEB and Sue C open pits commenced in 1999. Upon depletion, the JEB pit was converted to a Tailings Management Facility (TMF). The Sue C pit will be converted to a TMF for the disposal of waste from the McLean Lake and Cigar Lake
Cigar Lake Mine
The Cigar Lake Mine is the largest undeveloped high grade uranium deposit in the world, located in the uranium rich Athabasca Basin of northern Saskatchewan, Canada....
operations. Production from the Sue A mine and development of the Sue E mine, commenced in mid 2005.
After the tailings from the milling operations and waste rock from the mining operations are chemically treated to precipitate arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
and nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
they are pumped into the TMF. There they form a consolidated mass of much lower permeability than the surrounding sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
. As a result the groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
flow is diverted around the tailings. By these means the water quality in adjacent Fox and Pat Lakes is expected to be maintained within Saskatchewan Surface Water Quality Objectives over the long term (10,000 years). This expectation has to be confirmed by monitoring subject to oversight by the CNSC.