Coal fly ash as a potential fixation reagent for radioactive wastes

FUEL

卷:153

Article

Lieberman, Roy Nir^1,2,3  Green, Uri¹  Segev, Giora^1,4  Polat, Mehmet⁵  Mastai, Yitzhak^2,3  Cohen, Haim^1,6 

[1] Ariel Univ Samaria, Dept Biol Chem, IL-40700 Ariel, Israel

[2] Bar Ilan Univ, Dept Chem, Ramat Gan, Israel

[3] Bar Ilan Univ, Inst Nanotechnol, Ramat Gan, Israel

[4] Israel Atom Energy Commiss, Tel Aviv, Israel

[5] Izmir Inst Technol, Dept Chem Engn, Izmir, Turkey

[6] Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel

关键词: Fly ash;    Radioactive;    Waste;    Fixation;    Carbonate;   

DOI  :  10.1016/j.fuel.2015.02.111

来源: Elsevier

【 摘 要 】

Israel produces similar to 1.3 Mt/year of fly ash (FA), a byproduct of its coal-fired power plants. Due to increasing environmental regulations, these imported coals are processed to reduce the sulfur concentration (similar to 0.6%). These processing methods result in a material that has an enriched alkali/alkali earth component with pozzolanic and basic properties (pH > 10.5). FAs are utilized worldwide, mainly as a cement additive for the construction industry. Recently, it was demonstrated that Class F FA can act as an excellent fixation reagent for acidic wastes from the phosphate or the oil regeneration industries. In the current work the potential utilization of Class F FAs as fixation reagents for low-activity radioactive waste from the nuclear industry was examined. Aqueous solutions containing radionuclide simulants: cesium (Cs+), strontium, (Sr2+), and cerium (Ce3+, Ce4+) were used as case studies with promising results. It is suggested that the primary fixation mechanism involves the aluminate/silicate anions at the FA surface. A novel experimental fixation approach utilizing the formation of carbonates is demonstrated and a new interaction mechanism is suggested based on the electrostatic interactions of the positively charged fine precipitates with the negatively charged FA surface. (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

Free