Zirconium extraction

Brewer, K.N., Herbst, R.S., Todd, T.A., Christian, J.D. 1998. Zirconium extraction into octyl-(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide and tributyl phosphate. Solvent Extr. IonExch. 16 (4) 1047-1066. 

When researching the process of zirconium extraction by tributyl-phosphate from nitric acid solution, two factors, Xi and X2 have been analyzed. The observed factors and response are shown by these relations ... 

Swanson, J. L Neptunium and Zirconium Extraction under Purex HA Column Scrub Conditions, Report BNWL-1588, 1971. 

The dependence of zirconium extraction as Zr(TTA)4 in the presence of sulphate was examined from 0 to 0.2726 M sulphate, at a total acidity of 2 M. The results, in relation to the following reaction ... 

The dependence of zirconium extraction as Zr(TTA)4 in the presence of chloride and nitrate was determined from two measurements for each ligand. The data were used to indicate that the species formed were ZrCl and ZrNOf. A statistical re-evaluation of the reported data indicate that the stability constants (y0,) for these species are (2.1 0.2) and (1.97 0.14), respectively, or logn,/ , (ZrCT ) = (0.32 0.04) and logio P (ZrNOj ) = (0.29 0.03) the uncertainties have been calculated considering the differences in, and uncertainty of, the data given by the authors and then changed to 95% confidence levels. It is not recommended to include these data in the review for the following reasons (a) the inadequacy in the number of experimental data points (b) the authors believed that the presence of an unknown impurity may have effected the stability constants by as much as 30% and (c) on the basis of other reported data it is likely that not only ZrCP or ZrNOj form in the experimental conditions studied. 

In the zirconium extraction process, several corrosive chemicals are used, including methyl isobutyl ketone, HCl, ammonium thiocyanate, H2SO4, and zirconyl chloride. Zirconium has been foimd to withstand the rigors of this manufacturing process. Six examples are given, as follows ... 

An important goal of the zirconium extraction example given in Problem 8.1.18 is to obtain a solvent extract stream containing zirconium substantially purified of hafnium. It is known that the value of k,i of Hf is 0.11. Determine the value of the separation factor for zirconium vis-a-vis hafnium in the extract stream for case (b) of Problem 8.1.18. This separation factor has also been called the decontamination factor (Benedict et al., 1981,... 

---