RECOVERY OF URANIUM FROM SLAG FROM THE ELECTRIC FURNACE PRODUCTION OF PHOSPHORUS

v When phosphate rock is reduced to elemental phosphorus with coke in the electric furnace process, the uranium in the phosphate rock virtually all goes into the byproduct slag. It is estimated that approximately 300 tons of uranium is potentially recoverable per year from this use of phosphate rock. Previous work at Battelle Memorial Institute, Mound Laboratory, and the Tennessee Valley Authority did not result in an economic process for the recovery of uranium from electric furnace slags. The present investigati on included thermal reductions with alkaline earth metals, hi gh temperature liquidliquid extraction with molten extractants, solubilizing fusions, magnetic separations, and leaching with various solutions. As an adjunct to the high temperature liquid-liquid extraction studies, the solubility of uranium in antimony, bismuth, lead, silver and tin were further studied, to corroborate and extend existing data. Radioassay methods of analysis were developed for the raw furnace slags and residues from the various experimental treatments. A fraction of the slag residues were checked for uranium using a colorimetric procedure o All binary alloys resulting from the uranium solubility study were analyzed with colorimetric procedures developed during the course of the investigation. The results of the thermal reduction experiments do not indicate a concentration of uranium in either layer of mechanically partitioned slag residues . Bi smuth,. lead and manganese appear to extract the most uranium from furnace slags by a single contact of the metal with the slag. In all high temperature extraction treatments, about So per cent of the uranium appeared amena~le to extraction. The addition of calcium, magnesium, aluminum and potassium to the melt with iron * This report is based on a Ph.D. thesis by H. z. Cammack, submitted August , 1955, to Iowa State College, Ames, Iowa. This work was performed under contract with the Atomic Energy Commission.