Overview

Mine Type	In-Situ
Status	Care and Maintenance
Commodities	Uranium
Mining Method	Solution mining
Production Start	...
Snapshot	Cameco’s operations in the United States, Crow Butte and Smith Ranch-Highland, are not currently producing as the decision was made in 2016 to curtail production and defer all wellfield development. As a result of 2016 decision, commercial production at the US operations ceased in 2018. The current operating licence for Crow Butte expires in October 2024. Efforts are underway for re-licensing with the Nuclear Regulatory Commission. Cameco do not expect any production in 2024.

Deposit type

• Sandstone hosted

Summary:

The Crow Butte uranium deposit is a sandstone-type, roll-front uranium deposit, and is contained within the Chadron sandstone, at the base of the Oligocene Chadron Formation.

The Chadron uranium deposits are roll-front deposits formed by the precipitation of uranium from uranium- rich, oxidizing waters as they moved into or through a reducing aquifer. Because the uranium was transported by, and precipitated from, groundwater, an interpretation of the development of the groundwater system through geologic time has been made to identify factors controlling uranium accumulation.

Petrographic data (e.g., U-bearing matrix at grain contacts) indicate that U mineralization occurred before lithification of the sandstone. Dissolution of abundant rhyolitic volcanic ash produced U- and Si-rich ground waters that were channeled through permeable sandstones at the base of the Chadron by relatively impermeable overlying and underlying beds. The precipitation of early authigenic pyrite created a reducing environment favorable for precipitation and accumulation of U in the basal sandstone. The U has remained in a reduced state, as evidenced by the fact that the unoxidized minerals, coffinite and uraninite, comprise the bulk of the ore. At least some U and V remain bound to amorphous volcanic material and/or smectite rather than existing as discrete mineral phases.

The Chadron sandstone, which hosts the Crow Butte deposit, consists of coarse-grained, cross-bedded sandstone, with thin lenses of gravel-size conglomerate and interbedded clay layers. The sandstone is composed of 65% quartz, 25% feldspar and 10% rock fragments. The sediments also contain up to 30% air-fall ash in places.

Mining Methods

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Comminution

Crushers and Mills

Processing

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Production

Personnel

Job Title	Name	Phone	Email	Profile	Ref. Date
.......................	.......................	...........	...........		Sep 7, 2023
.......................	.......................	...........	...........		Aug 19, 2022
.......................	.......................				Feb 29, 2024

Employees	Year
......	2015