Production of uranium
Currently, the United States imports about 92% of the uranium it needs each year.
Colorado has about 35 active mining permits for uranium, but no present production. About $16 million worth of uranium was produced in the state in 2008, and $7 million in 2005.
There are two major forms of uranium mining: Hard-rock mining and In-Situ Leaching (ISL).
Hard-rock mining involves determining where a vein of commercially valuable ore is located and extract it using mechanical means until the supply is exhausted.
It is very common for a mine to be shut down until prices and demand make it economically viable to re-open the facility.
Image: Burro Mine, Courtesy of the Colorado Geological Survey
The economics of uranium mining are difficult because of a lack of milling capacity in the country. A proposed new mill in the Paradox Valley in western Colorado is wending its way through the permitting process.
|In situ leaching (ISL), also known as solution mining, or in situ recovery (ISR) in North America, involves leaving the ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. Consequently there is little surface disturbance and no tailings or waste rock generated. However, the orebody needs to be permeable to the liquids used, and located so that they do not contaminate groundwater away from the orebody.
In 2011, 45% of world uranium mined was from ISL operations.
Colorado's Uravan Mining District is the oldest uranium district in the nation. The Uravan belt has about 1,200 historic mines that produced over 63 million pounds of uranium and 330 million pounds of vanadium from 1948 to 1978.