Recent Examples on the WebGreen Salt was a small-scale way of producing tetrafluoride, an intermediate step in the process of producing feed material for uranium enrichment. Laurence Norman, WSJ, 25 May 2022 In 2005, Iran acknowledged converting yellowcake into uranium tetrafluoride, a step below the uranium hexafluoride needed for centrifuges.The Christian Science Monitor, 28 June 2018