Uranium Mining & Milling
The ore is crushed and milled to separate the uranium. An intermediate product known as yellowcake (U3O8), because of its distinctive color, is produced. The yellowcake is shipped out of province for conversion and enrichment and the manufacture of fuel for nuclear power reactors. Once processed, 450 kg of yellowcake contains enough energy to supply the electrical needs of the residents of a city the size of Melfort, Saskatchewan, for one year.
Milling uranium ore includes several steps. Usually, the mill is located near the mine site.
- The uranium ore is trucked to the mill where the uranium is extracted from the ore.
- The ore is crushed and ground to a fine powder.
- Chemicals are added to dissolve the uranium, producing a slurry of waste and uranium.
- Sulphuric acid is mixed with the slurry to separate the uranium and other elements from the solid part of the slurry.
- The uranium is extracted from the other elements and converted to a solid form called yellowcake (uranium concentrate), which is 60% to 70% uranium and radioactive.
- Once the yellowcake is dried, it is packed in steel drums that conform to the standards set for transportation of hazardous products. Trucks transport the containers from the mills to refineries in Ontario and the United States for further processing.
- The refined uranium concentrate is processed to form hard ceramic pellets. This is done by using chemicals to extract nearly all the uranium from the uranium powder. The pure uranium trioxide (UO3) is shipped to the conversion facility where it is converted by chemical means to uranium dioxide (UO2) and uranium hexaflouride (UF6).
- Uranium concentrate pellets (uranium dioxide) are fuel for the CANDU nuclear reactor. The pellets are placed in rods and packed in a fuel bundle about 10 cm in diameter and 50 cm long, weighing about 25 kg. Seven such pellets produce enough electricity to meet the annual electricity needs of the average Canadian home. Uranium hexaflouride is used in producing fuel for other reactors.