Radiological characterization of clay mixed red mud in particular as regards its leaching features. (October 2016)

• Record Type: Journal Article
• Authors: Hegedűs, Miklós; Sas, Zoltán; Tóth-Bodrogi, Edit; Szántó, Tamás; Somlai, János; Kovács, Tibor
• Is Part Of: Journal of environmental radioactivity. Volume 162/163(2016:Oct.)
• Page Start: 1
• Page End: 7
• Publication Date: 2016-10
• Subjects: Red mud -- Radon exhalation -- By-product -- Leaching -- Building material industry -- Alpha spectrometry -- Gamma spectrometry; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2016.05.002
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: The reuse of industrial by-products such as red mud is of great importance. In the case of the building material industry the reuse of red mud requires a cautious attitude, since the enhanced radionuclide content of red mud can have an effect on human health. The natural radionuclide content of red mud from the Ajka red mud reservoir and the clay sample from a Hungarian brick factory were determined by gamma spectrometry. It was found that maximum 27.8% red mud content can be added to fulfil the conditions of the EU-BSS. The effect of heat treatment was investigated on a red mud-clay mixture and it was found that in the case of radon and thoron exhalation the applied heat reduced remarkably the exhalation capacities. The leaching features of red mud and different mixtures were studied according to the MSZ-21470-50 Hungarian standard, the British CEN/TS 14429 standard and the Tessier sequential extraction method. The Tessier method and the MSZ-21470-50 standard are suitable for the characterization of materials; however, they do not provide enough information for waste deposition purposes. To this end, we propose using the CEN/TS 14429 method, because it is easy to use, and gives detailed information about the material's behaviour under different pH conditions, however, further measurements are necessary. Highlights: Natural radionuclide content of red mud was determined by gamma spectrometry. Maximum mixing ratio of Ra-226, Th-232 and K-40 was calculated according to EU-BSS. The radon/thoron exhalation determined by accumulation chamber technique. Leachability of red mud and different mixtures was studied by extraction methods.