Exchange properties of cyanide complexes Part I. Ion exchange of cesium on ferrocyanides

摘要

Some heavy metal ferrocyanides were prepared and their selectivity towards cesium was investigated. Many were found to have good ion exchange properties and some can be easily prepared in a granular form suitable for the use in a packed column operation. The ferrocyanides show high cesium uptake in various simulated processing solutions relevant to the treatment of radioactive wastes. The amount of cesium sorbed by these hexacyanoferrates exceeded 99%. They also possess a high selectivity for cesium in solutions of high salt concentration. Desorption of the sorbed cesium at various nitric acid concentrations have been investigated and it is concluded that cesium is eluted by a chemical reaction step as a consequence of the oxidation of the ferrocyanides. It has also been observed that ferrocyanides degrade in solutions of low pH.