This invention is concerned with specific improvements in the production of uranium oxide suitable for use in the manufacture of fissionable nuclear fuel, from uranium hexafluoride by means of a gaseous reaction process with a fuel gas and oxygen. This process is commonly referred to in the patent literature as a flame or combustion conversion, a procedure set forth in considerable detail in the above identified U.S. patents, particularly U.S. Pat. No. 3,786,120.
As is known in the relevant art and industry, the physical properites as well as the chemical composition, or oxygen/uranium ratio of uranium oxide are conditions having an impact upon the manufacture and/or the subsequent performance of fissionable uranium fuel. The significance of certain aspects as the oxygen/uranium composition ratio and physical properties, such as particle size, surface characteristics and density, for uranium oxide destined for fissionable fuel service, relative to both its suitability for fuel manufacturing processes and subsequent performance as fuel, are somewhat illustrated by the contents of U.S. Letters Pat. No. 3,803,273; No. 3,923,933; and No. 3,927,154. For example, particle size and particle size distribution, among other factors, are of significance with respect to subsequent fuel manufacturing operations such as forming consolidated pellets of uranium oxide for utilization as fuel, and with respect to ultimate sintered pellet properties.