Ion exchange properties of a cesium ion selective titanosilicate

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Solvent Extraction and Ion Exchange

DOI:https://doi.org/10.1080/07366299608918343· OSTI ID:232474

Bortun, A I; Bortun, L N; Clearfield, A ^[1]

---

1. Texas A&M Univ., College Station, TX (United States)

The ion exchange properties of crystalline and amorphous phases of a sodium titanosilicate towards alkali and alkaline earth cations has been examined. Potentiometric titration of the crystalline phase in the proton form, H{sub 2}Ti{sub 2}O{sub 3}(SiO{sub 4}), showed that 80% of the sodium ion sites could be occupied to pH=12 and only 25% of the exchange sites could be filled by Cs{sup +}. However, when an equal concentration of Na{sup +} was present in the Cs{sup +} solution, the cesium loading was reduced to 5.6% (0.47meq/g) of the theoretical IEC. This loading is further reduced to less than 0.1 meq/g in solutions approximating the sodium content of nuclear waste solutions, i.e., 5-6 M NaNO{sub 3}, 1-3 M NaOH. This low capacity limits the usefulness of this exchanger to waste solutions less than 10{sup -5}-10{sup -6} M in Cs{sup +}. The amorphous phase exhibits a very high affinity for Sr{sup 2+} but also for Ba{sup 2+} and Ca{sup 2+} in alkaline solution. These ions could serve as interferences for selective Sr{sup 2+} removal from nuclear waste solutions. Sodium titanium silicate has a tunnel structure. The low capacity of the exchanger for Cs{sup +} stems form the fact that only a few of the exchange sites can be filled with Cs{sup +} in the presence of Na{sup +} and still maintain charge balance. 12 refs., 7 figs., 2 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 232474
• Journal Information: Solvent Extraction and Ion Exchange, Journal Name: Solvent Extraction and Ion Exchange Journal Issue: 2 Vol. 14; ISSN 0736-6299; ISSN SEIEDB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ABUNDANCE
ALKALINE EARTH METALS
CESIUM IONS
ION EXCHANGE
ION EXCHANGE MATERIALS
RADIOACTIVE WASTE PROCESSING
SEPARATION PROCESSES
SODIUM IONS
TITANIUM SILICATES