Nuclear 101: Uranium Milling

Welcome to the 9th segment of Nuclear 101. In the previous segment the various methods of uranium mining were discussed. Almost 70% of all uranium mining occurs in five countries: Australia (which tops the list at 31%), Kazakhstan, Russia, Canada, and Niger. After uranium is extracted from the ground it needs to be milled and processed into a usable powder known as “yellowcake.”

The milling process begins when uranium ore that has been mined is crushed and ground into fine fragments. Water is added to create a substance referred to as "slurry." In the next process, known as leaching, chemicals are added to separate the uranium from any other element that may be present in the slurry. As shown on the chart, this is a multi-step process. About 90-95% of the uranium can be extracted from the slurry through the process of leaching.

The extracted product is then dried resulting in uranium oxide U3O8. This oxidized uranium powder can be yellow, as the name “yellowcake” implies, or it can range from tints of red and orange to dark green depending on impurities not completely removed during leaching.

"Yellowcake"

Below is a short video that walks through an underground mining operation and the process of milling. It is worthwhile to watch to get a better understanding of the complex process it actually is to create uranium oxide U3O8, “yellowcake”.

Rebel fighter among the drums. Photo: David Rose.

Current Event:
In 2011, at least 6,400 drums of yellowcake were discovered unguarded in the Libyan desert which apparently had been dumped by Colonel Gaddafi after he ended the Libyan nuclear weapons program and was unsuccessful in selling the oxidized uranium on the world market. Yellowcake is not only a radiological material- that can transform a high yield explosive into a more devastating dirty bomb,- but is also only one step away from being usable for the process of enrichment, which is the subject of the next Nuclear 101 segment. Although once enriched, uranium can be used for peaceful energy purposes, it can also be used for weapons development. After two years and reports that there may be less than benign interest in acquiring the material, Russia has asked the United Nations Security Council in early November 2013 to take measures to secure the unguarded stockpile of yellowcake. Thus far, the material is still unsecured.

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Sources:
GeoInfo: NM Bureau of Geology
HSW: Uranium Milling
RT: Russia implores UN to take control of Libya’s ‘unguarded’ yellowcake uranium
Telegraph: Dumped in the desert ... Gaddafi’s yellowcake stockpile
U.S. Nuclear Regulatory Commission (1)
U.S. Nuclear Regulatory Commission (2)
World Nuclear Association (1)
World Nuclear Association (2)