Initially, the compounds formed in yellowcakes were not identified; in 1970, the U . S . Bureau of Mines still referred to yellowcakes as the final precipitate formed in the milling process and considered it to be ammonium diuranate or sodium diuranate.
12.
In this first phase of operation from 1958 to 1963 Mary Kathleen treated 2.9 million tonnes of ore at an average grade of 0.13 % to yield 4082 t ( 4500 short tons or 9 million pounds weight of U3O8 ) of uranium concentrate ( then actually yellowcake-ammonium diuranate ) containing 3460 tonnes of uranium.
