Complex sentence: Along with ammonium diuranate it was a component in early yellowcakes, the ratio of the two species determined by process conditions; yellowcake is now largely a mix of uranium oxides.
Split into simpler sentences: Along with ammonium diuranate it was a component in early yellowcakes. The ratio of the two species is determined by process conditions; however, yellowcake is now largely a mix of uranium oxides.