Uranium-preextraction in zirconium/hafnium separations process

In a process for recovering zirconium values from uranium containing zircon ore, said process comprising a fluidized bed carbochlorination of the zircon ore at about 1000.degree. C., producing a relatively impure, hafnium-containing zirconium tetrachloride stream and by-product silicon tetrachloride, with silicon tetrachloride by-product is separated by differential condensation, and wherein uranium chloride is volatilized at the ore chlorinator temperature and follows as an impurity in the zirconium-hafnium tetrachloride stream, mixing the zirconium-hafnium tetrachloride with water to produce a zirconium-hafnium oxychloride solution, removing iron impurities by liquid-liquid iron extraction with a methyl isobutyl ketone extractant, adding thiocyanate to the zirconium-hafnium oxychloride solution to produce an aqueous zirconium-hafnium oxychloride thiocyanate complex solution, and performing a separation step to reduce the hafnium content to low levels by liquid-liquid hafnium extraction of aqueous zirconium-hafnium oxychloride thiocynate complex solution using methyl isobutyl ketone;

• the improvement comprising:
• adding 1-9 weight percent quaternary ammonium halide to the methyl isobutyl ketone extractant in said liquid-liquid iron extraction;
• whereby the ethyl isobutyl ketone extractant strips uranium and iron from the zirconium-hafnium oxychloride solution and thus the uranium does not end up in the hafnium chlorinator residue;
• whereby the yield of hafnium can be increased by recycling of the hafnium chlorinator residue, the exposure of personnel to uranium is minimized, and the production of relatively pure, marketable uranium hydroxide and essentially uranium-free zirconium oxide are made possible.