Cu Resin is used for the selective separation of cop-per, and more particularly for the separation of Cu-64 and Cu-67 radio-isotopes. The CU Resin has been characterized for different elements, especially for those representative of Zinc or enriched Nickel tar-gets, and for different acidic media.
Cu Resin retains selectively copper from pH 2 to 5 for HCl, HNO3 and H2SO4 acids over all the tested cations including Ni and Zn. In HCl and H2SO4 media, iron is co-extracted but in a lesser extent: the selec-tivity Cu/Fe, αCu/Fe, decreases as pH increases (αCu/Fe is about 1000 at pH 2 and about 70 at pH 5) (Fig 1-3).
Cu uptake is generally high at pH values greater than 2 while it can be easily eluted with mineral acids of concentrations greater than 0.1M.
Main application of the CU resin is the separation of Cu isotopes (e.g. Cu-64, Cu-67) from irradiated tar-gets (typically Zn or Ni targets). Accordingly, besides having high selectivity for Cu over Ni and Zn, the res-in also has to be robust against interference by ele-vated amounts of Zn and Ni. Figures 2a and 2b sum-marize the influence of Zn or Ni on the Cu extraction. As can be seen even high amounts of both elements interfere only slightly with the Cu uptake in HCl at pH 2, even at 1g of Ni or Zn per g of CU resin employed the DW(Cu) remains greater than 1000.
A method for the separation of Cu from Ni and Zn targets was opti-mized using simulated target solutions (1). Two types of solutions were tested:
simulated Ni target solutions containing 10 μg each of Cu, Co, Zn and 200 mg of Ni in 5 mL HCl at pH 2,
simulated Zn target solutions containing 10 μg each of Cu, Co, Ni and 200 mg Zn in 5 mL HCl at pH 2)
For both simulated target solutions, Ni, Zn and Co are quantitatively removed from the column during sample solution loading and rinsing whereas Cu is recovered in high yield (>85%) in 1 – 1.5 mL 8M HCl (2,3).
Further optimization of the elution conditions led to the method shown in Figure 3 (2).
The method can be performed at elevated flow rates (e.g. using a vac-uum box) without impacting its performance. Loading of the column and Cu elution should be done at approx. 1 mL/min, rinsing of the col-umn can be done at up to 6 mL/min; the final Cu fraction can thus be obtained in 3 – 5 minutes.
Overall decontamination factors obtained are high (Table 1). Cu yields were found to be in the order of 90% in 1 mL of 8M HCl and > 95% in 1.5 mL 8M HCl; Cu is thus recovered near quantitatively in a very small volume.
For certain applications the Cu eluate might be too acidic, in these cases (alternative to evaporation of the Cu fraction and redissolution in a more suitable solvent) it is possible to convert the Cu eluate using a small anion exchange column. Fig. 4 schematically shows such a con-version method using anion exchange resin (AIX resin). In addition to the converting the Cu elute from high acid conditions to low acid or neutral conditions the conversion step also further concentrates the Cu and increases Ni, Zn, Au and organic impurity decontamination.
CU Resin is manufactured in one particle size 100-150μ and is only available in bottles at this time.
|Particle Size||Bottles||Part Number|
|100-150 μ||25 grams||CU-B25-A|