| 摘要 |
There is disclosed, in a process for separating zirconium and hafnium, an improvement for the removal of sodium sulfate from a sulfate-containing sodium chloride solution. This improvement includes adding a water-miscible organic precipitant such as methanol, ethanol or acetone to the sulfate-containing sodium chloride solution. The precipitant is added in an amount sufficient to cause the removal of sulfate as sodium sulfate. The organic precipitant is removed and the substantially sulfate ion free sodium chloride solution is recycled. Also provided is a process for the recovery of sodium sulfate having a purity greater than 99.9%. This process includes the steps of adding a first amount of a water-miscible precipitant to a zirconium-loaded aqueous solution, this first amount being insufficient to produce sodium sulfate crystal formation, contacting the resulting solution of the prior step with a zirconium-precipitating base to form a zirconium precipitate, passing the resulting treatment mixture to a separation stage from which there is obtained the zirconium precipitant and the sodium sulfate-containing sodium chloride solution, and adding a second amount of the precipitant to this sodium sulfate-containing sodium chloride solution whereby sodium sulfate crystals are formed.
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