A cesium-selective ion sieve made by topotactic leaching of phlogopite mica.

Ahydrated, sodium phlogopite mica with a c-axis spacing [d(001)] of 12.23 A made by careful low-temperature leaching, showed extremely high selectivity for cesium. This newly discovered cesium ion sieve is useful in the decontamination as well as immobilization of cesium at room temperature through chemical bonding and may find applications in nuclear waste disposal and in decontamination of the environment after accidental releases of nuclear materials.