必和必拓
In 1989 Quivira was bought by Rio Algom Mining, LLC, which was then bought by Billiton in 2000. Billiton then merged with BHP to form BHP Billiton in 2001. Rio Algom was then bought from BHP Billiton by Uranium Resources, Inc. (URRE) in 2007. In June, 2008 Uranium Resources, Inc. announced it would terminate the agreement to purchase Rio Algom Mining from BHP Billiton.