title: Radon exhalation study of manganese clay residue and usability in brick production.
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 radionuclides40K,226Ra and232Th 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.
authors.affiliation: Institute of Radiochemistry and Radioecology, University of Pannonia, 10 Egyetem Str., H-8200, Veszprém, Hungary; Social Organisation for Radioecological Cleanliness, 7/a József Attila Str., H-8200, Veszprém, Hungary. Electronic address: kt@almos.uni-pannon.hu.
authors.forename: Tibor
authors.initials: T
authors.lastname: Kovács
authors.affiliation: Institute of Radiochemistry and Radioecology, University of Pannonia, 10 Egyetem Str., H-8200, Veszprém, Hungary.
authors.forename: Amin
authors.initials: A
authors.lastname: Shahrokhi
authors.affiliation: Institute of Radiochemistry and Radioecology, University of Pannonia, 10 Egyetem Str., H-8200, Veszprém, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Sas
authors.affiliation: Mangan Mining and Processing Ltd., Külterület 1, H-8409, Úrkút, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Vigh
authors.affiliation: Institute of Radiochemistry and Radioecology, University of Pannonia, 10 Egyetem Str., H-8200, Veszprém, Hungary.
authors.forename: János
authors.initials: J
authors.lastname: Somlai
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D003252:Construction Materials / Q000032:analysis*; D008345:Manganese / Q000737:chemistry; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D013696:Temperature
chemical_list: D000396:Air Pollutants, Radioactive; D000538:Aluminum Silicates; D008345:Manganese; D011886:Radon; D000077215:Clay
keywords: Building material; Emanation; Exhalation; Heat-treatment; Manganese clay; Radiation hazard; Radon