Radon exhalation study of manganese clay residue and usability in brick production. (March 2017)

• Record Type: Journal Article
• Authors: Kovács, Tibor; Shahrokhi, Amin; Sas, Zoltán; Vigh, Tamás; Somlai, János
• Is Part Of: Journal of environmental radioactivity. Volume 168(2017:Mar.)
• Page Start: 15
• Page End: 20
• Publication Date: 2017-03
• Subjects: Manganese clay -- Heat-treatment -- Radiation hazard -- Radon -- Emanation -- Exhalation -- Building material; 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.2016.07.014
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: The reuse of by-products and residue streams is an important topic due to environmental and financial aspects. Manganese clay is a residue of manganese ore processing and is generated in huge amounts. This residue may contain some radionuclides with elevated concentrations. In this study, the radon emanation features and the massic exhalation rate of the heat-treated manganese clay were determined with regard to brick production. From the manganese mud depository, 20 samples were collected and after homogenization radon exhalation characteristics were determined as a function of firing temperatures from 100 to 750 °C. The major naturally occurring radionuclides 40 K, 226 Ra and 232 Th concentrations were 607 ± 34, 52 ± 6 and 40 ± 5 Bq kg −1, respectively, comparable with normal clay samples. Similar to our previous studies a strong correlation was found between the internal structure and the radon emanation. The radon emanation coefficient decreased by ∼96% from 0.23 at 100 °C to 0.01 at 750 °C. The massic radon exhalation rate of samples fired at 750 °C reduced by 3% compared to samples fired at 100 °C. In light of the results, reusing of manganese clay as a brick additive is possible without any constraints. Highlights: Firing temperatures affect radon emanation and exhalation rate of manganese clay. The radon exhalation was determined using accumulation chamber technique. Investigation of naturally occurring radionuclides in manganese clay samples. Reusing of manganese clay as an additive material in brick was surveyed.