Ion Exchange Performance of Titanosilicates, Germanates and Carbon Nanotubes

Abstract

This report presents a summary of testing the affinity of titanosilicates (TSP), germaniumsubstituted titanosilicates (Ge-TSP) and multiwall carbon nanotubes (MWCNT) for lanthanide ions in dilute nitric acid solution. The K-TSP ion exchanger exhibited the highest affinity for lanthanides in dilute nitric acid solutions. The Ge-TSP ion exchanger shows promise as a material with high affinity, but additional tests are needed to confirm the preliminary results. The MWCNT exhibited much lower affinities than the K-TSP in dilute nitric acid solutions. However, the MWCNT are much more chemically stable to concentrated nitric acid solutions and, therefore, may candidates for ion exchange in more concentrated nitric acid solutions.This technical report serves as the deliverable documenting completion of the FY13 research milestone, M4FT-13SR0303061 -measure actinide and lanthanide distribution values in nitric acid solutions with sodium and potassium titanosilicate materials. Ion Exchange Performance 5 ACRONYMS CST crystalline silicotitanate Ge-TSP germanium-substituted titanosilicate ICP-MS inductively coupled plasma mass spectrometry FCR&D Fuel Cycle Research and Development K d distribution value MWCNT multiwall carbon nanotube SRNL Savannah River National Laboratory TSP titanosilicate having the pharmacosiderite structure Ion Exchange Performance 6

Experimental Findings on Minor Actinide and Lanthanide Separations Using Ion Exchange

“…[2][3][4] During FY13, SRNL researchers investigated the synthesis of alkali metal titanosilicates using a microwave accelerated reaction system (MARS ® ). Powder X-ray diffraction patterns of the potassium titanosilicate (K-TSP) produced in the MARS ® after 3 hours at 180 ºC is nearly identical to that produced in a convention hydrothermal reactor after 8 days (see Figure 3).…”