CHEMICAL ENGINEERING DIVISION SUMMARY REPORT FOR OCTOBER, NOVEMBER, DECEMBER 1958

Fluoride Volatilization Separations Process. Work has continued on the development of fluoride volatilization processes for recovery of U and Pu from spent power-reactor fuels. Results are reported on the fluorination rates of U and Pu oxides and fluorides. The conversion rate of UO/sub 2/F/sub 2/ to UF/sub 6/ by elemental fluorine was determined as a function of temperature. Uranium trioxide is fiuorinated at a slower rate than the other U compounds investigated. On exposure to fluorine PuO/sub 2/ appears to form the PuF/sub 4/, which, in turn, is converted to PuF/sub 6/. The product of the thermal deconmposition ofPuF/sub 6/ is PuF/sub 4/. The fluorination of Ni at 600 to 800 C produces films of a higher density than that of crystalline NiF/sub 2/. Flourination studies on Ti, Pt, Au, and Ag indicated that none of these netals is suitable for use with fluorine at temperatures much above 100 C. Development work continued on a high-temperature fusedsalt process for the recovery of enriched U from Zrdissolver-hydrofluornator made of graphite is nearly Reactor (LMFR) core fluid by a floride volatility process is being investigated. Fluidization Studies. Investigaition of the effect of process variables on the fluidion steps of the ADF d material meter fluid-bed fluorinator of U removal. Corrosion results of additional specistantiate the excessively high vapor-phase corrosion of Ni observed previously. Additional runs in the fluid-bed lar solid, indicated that Ru decontamination factors from feed through silica gel adsorbed of 10/sup 3/ to 10/sup 4/ be achieved. Corrosion experiments on sintered stainose in the Chemistry. the program to clarify the factor governing the pyrophoric characteristics of U, Zr, Th, and Pu has continued with studies of kinetics and mechanism of ported. Chemical-Metallurgical Processing. No removal of Zr from a Pu-"fissium" alloy was relized by melt refining in either lime-stabilized ZrO/sub 2/ or MgO crucibles. In connection with the removal of Zr as the carbide, information has been obtained on the joint solubilities of Zr and C in U at 1400 C. Progress was made in the melting of oxide-coated pins by reduction of the oxide coating, using Mg in a Zn solution. A method proposed for proccssing U to separate the noinc process. the solubilities of Zr, Mo, Th, and Nb in Zn DEC. Zn solutions have been measured. Measurements of vapor and decomposition pressure have been made on the U -Zn system. The separation of fission products from irradiated U by extraction with a fused salt of a Zn or Cd solution has been investigated. Work continued on the application of a Zn-Mg solution process to recovery and purification of Pu from blanket material. Corrosion tcsting of various metals is being carried out in both Zn and Cd systems. Tantalum and W wave withstood attack by Zn at 800 C in static tests. A number of metals, including iron and steel, were resistant to attack by Cd and Cd --U alloys. Thc design of cranes ported on the synthesis and ;analyis of pure MoS//sub 2/. Work hkas begun on the combustion of Mo in fluorine for (For preceding period see ANL-5924.) (W.L.H.