INTERNATIONAL MOTIVATION AND COOPERATION FOR RESEARCH IN THE ULTRA-HIGH PURIFICATION OF METALS

Due to the dramatic change in the properties as the last traces of impurities are removed, ultra-high purity metals can be considered to be new functional materials that find dynamically growing applications in a number of specialized fields in modern technology, especially in electronics. The objective of this research is to define purity levels and discuss the challenges involved in achieving them. The methodology involves examining both direct analytical methods, which may lack high accuracy for all elements, and indirect methods that primarily utilize testing of the residual resistivity at 4.2 K, providing a global index of purity when material conditions are standardized. Results indicate that conventional purification techniques often require multiple treatment steps that may be inefficient. However, the purification process utilizing anion-exchange shows great promise for the effective separation of impurities from base metals dissolved in HCl solutions, aided by significant differences in chloro-complex formation and ion-exchange sorption. Selectivity during this procedure can be achieved through controlled HCl concentrations and redox conditions.