Solidification of selenate-bearing ettringite in glass-ceramics by using industrial by-products

Binglin Guo, Keiko Sasaki, Tsuyoshi Hirajima

Research output: Contribution to conferencePaper

Abstract

After accumulation of radionuclides from contaminated sources, spent absorbents and co-precipitated sludge is classified into radioactive wastes and should be stabilized before landfilling for long term storage. Therefore, development of efficient technologies to stabilize spent absorbents bearing radionuclides is urgently needed. In the present work, the ultilization of industrial by-products as raw materials to produce ceramics to stabilize radioactive waste was investigated using a surrogate. Selenate-doped ettringite was mixed with granulated blast furnace slag (GBFS) and silica fume (SF) and then calcined at various temperatures to produce glass-ceramics. Above 800 °C, the amorphous mixture was converted to glass-ceramics, which were subjected to the toxicity characteristic leaching procedure (TCLP) test. The synthesized ceramics exhibited excellent results for immobilization of selenate in which less than 0.1 mg/L of selenate was leached out. Moreover, according to the digestion experiment, the quantity loss of selenate in the ceramics was not observed even after calcination. The X-ray photoelectron spectroscopy (XPS) revealed the stabilization mechanism is based on encapsulation. In addition, the ceramic materials exhibited excellent chemical stability in a wide range of pH from 2 to 12. These results showed that industrial by-products can be successfully applied to produce ceramics for not only immobilization but also storage of hazardous wastes.

Original languageEnglish
Publication statusPublished - Jan 1 2017
Event14th International Symposium on East Asian Resources Recycling Technology, EARTH 2017 - Sapporo, Hokkaido, Japan
Duration: Sep 26 2017Sep 29 2017

Conference

Conference14th International Symposium on East Asian Resources Recycling Technology, EARTH 2017
CountryJapan
CitySapporo, Hokkaido
Period9/26/179/29/17

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All Science Journal Classification (ASJC) codes

  • Environmental Science(all)

Cite this

Guo, B., Sasaki, K., & Hirajima, T. (2017). Solidification of selenate-bearing ettringite in glass-ceramics by using industrial by-products. Paper presented at 14th International Symposium on East Asian Resources Recycling Technology, EARTH 2017, Sapporo, Hokkaido, Japan.