| 摘要 |
This is an improvement to a process for making zirconium metal from uranium-containing zircon ore. The process being improved is of the type which utilizes a fluidized bed carbochlorination process of the zircon ore in which uranium chloride is volatilized at the ore chlorinator temperature and follows as an impurity in the zirconium-hafnium tetrachloride stream, and in which removal of iron impurities is performed by liquid-liquid iron extraction with methyl isobutyl ketone, and the zirconium-hafnium stream is further processed by a separations step to reduce the hafnium content to low levels by liquid-liquid hafnium extraction. The improvement comprises adding 1-9 weight percent quaternary ammonium halide (e.g. tricaprylmethylammonium chloride) to the methyl isobutyl ketone in the liquid-liquid iron extraction. In this manner, the methyl isobutyl ketone strips uranium and iron from the zirconium-hafnium stream chloride solution and thus uranium does not end up in the hafnium chlorinator residue and yield of hafnium can increase by recycling of the hafnium chlorinator residue. In addition, exposure of personnel to uranium is minimized, and production of relatively pure, marketable uranium hydroxide and essentially uranium-free zirconium oxide are made possible.
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