From raw materials to NORM by-products

Kovács, Tibor; Bátor, Gergő; Schroeyers, Wouter; Labrincha, J.A.; Puertas, Francisca; Hegedűs, Miklós; Nicolaides, Demetris; Sanjuán, Miguel Ángel; Kryvenko, Pavlo; Grubeša, Ivanka Netinger; Sas, Zoltán; Michalik, B.; Anagnostakis, M.J.; Barišić, Ingeborg; Nuccetelli, Cristina; Trevisi, Rosabianca; Croymans, Tom; Schreurs, Sonja; Todorović, Nataša; Vaičiukynienė, Danutė; Bistrickaitė, Rėda; Tkaczyk, Alan H.; Kovler, Konstantin; Wiegers, R.; Doherty, Rory

doi:10.1016/b978-0-08-102009-8.00006-2

Cited by 18 publications

(18 citation statements)

References 88 publications

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“…When fly ash is mixed with Portland cement, the activity concentration index (ACI) in the resulting OPC + FA blends rises due to the increased presence of the gamma-ray emitting radionuclides used to calculate the index. The theoretical ACI values based on aluminium-or calcium-sulphate fly ash range from 1.2 to 1.3 [10,11,20,21,24,26,27], compared to pure Portland cement values of 0.2 to 0.3 [25,[28][29][30][31].…”

Section: Introductionmentioning

confidence: 92%

“…Fly ash, an industrial by-product generated in coal-fired steam power plants used as a mineral addition, is characterised by the high activity concentration of its natural radionuclides [10]. The natural radioactivity present in FA depends on the geological origin of the coal used and the ash particle size [22][23][24]. US Geological Surveys show that coal containing phosphate minerals such as monazite or apatite has high radioactive 232 Th concentrations, whereas coal containing both organic matter and mineral fractions has high 238 U radioactive series contents [25].…”

Section: Introductionmentioning

confidence: 99%

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New Approach for the Determination of Radiological Parameters on Hardened Cement Pastes with Coal Fly Ash

et al. 2021

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Supplementary cementitious materials (SCMs) in industrial waste and by-products are routinely used to mitigate the adverse environmental effects of, and lower the energy consumption associated with, ordinary Portland cement (OPC) manufacture. Many such SCMs, such as type F coal fly ash (FA), are naturally occurring radioactive materials (NORMs). 226Ra, 232Th and 40K radionuclide activity concentration, information needed to determine what is known as the gamma-ray activity concentration index (ACI), is normally collected from ground cement samples. The present study aims to validate a new method for calculating the ACI from measurements made on unground 5 cm cubic specimens. Mechanical, mineralogical and radiological characterisation of 28-day OPC + FA pastes (bearing up to 30 wt % FA) were characterised to determine their mechanical, mineralogical and radiological properties. The activity concentrations found for 226Ra, 212Pb, 232Th and 40K in hardened, intact 5 cm cubic specimens were also statistically equal to the theoretically calculated values and to the same materials when ground to a powder. These findings consequently validated the new method. The possibility of determining the activity concentrations needed to establish the ACI for cement-based materials on unground samples introduces a new field of radiological research on actual cement, mortar and concrete materials.

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

New Approach for the Determination of Radiological Parameters on Hardened Cement Pastes with Coal Fly Ash

et al. 2021

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“…Fairly recent evidence of radioactive emissions from those materials, however, necessitates acquiring an understanding of and as far as possible controlling such radioactivity. Those two materials are described in detail in (10) and (20).…”

Section: Norm Waste Used In Cement and Concrete Productionmentioning

confidence: 99%

“…The natural radioactivity of fly ash depends on the geological age of the original coal bed, the combustion process used and ash particle size; being of interest due to the accumulation of radioactivity -polonium 210 -in the smallest particles of fly ashes (20,56,57). US Geological Surveys show that coal containing phosphate minerals such as monazite or apatite have high radioactive 232 Th concentrations, whereas coal containing both organic matter and mineral fractions have high levels of the 238 U radioactive series (58).…”

Section: Coal-fired Power Plant Fly Ash and Botton Ashmentioning

confidence: 99%

NORM waste, cements, and concretes. A review

Puertas

Suárez-Navarro²,

Alonso

et al. 2021

materconstrucc

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The use of industrial waste and/or by-products as alternative sources of raw materials in building materials has become standard practice. The result, more sustainable construction, is contributing to the institution of a circular economy. Nonetheless, all necessary precautions must be taken to ensure that the inclusion and use of such materials entail no new health hazard for people or their environment. Due to the processes involved in generating industrial waste/by-products, these alternative or secondary materials may be contaminated with heavy metals, other undesirable chemicals or high levels of natural radioactivity that may constrain their use. In-depth and realistic research on such industrial waste is consequently requisite to its deployment in building materials. This paper reviews the basic concepts associated with radioactivity and natural radioactivity, focusing on industrial waste/by-products comprising Naturally Occurring Radioactive Materials (NORM) used in cement and concrete manufacture. Updated radiological data are furnished on such waste (including plant fly ash, iron and steel mill slag, bauxite and phosphogypsum waste) and on other materials such as limestone, gypsum and so on. The paper also presents recent findings on radionuclide activity concentrations in Portland cements and concretes not bearing NORMs. The role of natural aggregate in end concrete radiological behaviour is broached. The radiological behaviour of alternative non-portland cements and concretes, such as alkali-activated materials and geopolymers, is also addressed.

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“…It is well known that mining leads to environmental pollution by naturally occurring radioactive materials (NORM) and heavy metals. For most human activities involving minerals and raw materials, the levels of exposure to these radionuclides are not significantly greater than normal background levels, and when these raw materials with low concentrations of NORM are introduced in an industrial process, the radionuclides can become more concentrated in the produced by-products or in waste material such as red mud in bauxite mining [3,4]. Such activities significantly increase the exposure of workers and the general public, meaning that they may need to be controlled by regulation in order to ensure the protection from radiation of relevant people.…”

Section: Introductionmentioning

confidence: 99%

Indoor Radon Measurements Using Radon Track Detectors and Electret Ionization Chambers in the Bauxite-Bearing Areas of Southern Adamawa, Cameroon

Saïdou

Modibo

Emmanuel

et al. 2020

IJERPH

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The current work deals with indoor radon (222Rn) concentrations and ambient dose-equivalent rate measurements in the bauxite-bearing areas of the Adamawa region in Cameroon before mining from 2022. In total, 90 Electret Ionization Chambers (EIC) (commercially, EPERM) and 175 Radon Track Detectors (commercially, RADTRAK2) were used to measure 222Rn concentrations in dwellings of four localities of the above region. A pocket survey meter (RadEye PRD-ER, Thermo Scientific, Waltham, MA, USA) was used for the ambient dose-equivalent rate measurements. These measurements were followed by calculations of annual doses from inhalation and external exposure. 222Rn concentrations were found to vary between 36 ± 8–687 ± 35 Bq m−3 with a geometric mean (GM) of 175 ± 16 Bq m−3 and 43 ± 12–270 ± 40 Bq m−3 with a geometric mean of 101 ± 21 Bq m−3 by using EPERM and RADTRAK, respectively. According to RADTRAK data, 51% of dwellings have radon concentrations above the reference level of 100 Bq m−3 recommended by the World Health Organization (WHO). The ambient dose equivalent rate ranged between 0.04–0.17 µSv h−1 with the average value of 0.08 µSv h−1. The inhalation dose and annual external effective dose to the public were assessed and found to vary between 0.8–5 mSv with an average value of 2 mSv and 0.3–1.8 mSv with an average value of 0.7 mSv, respectively. Most of the average values in terms of concentration and radiation dose were found to be above the corresponding world averages given by the United Nations Scientific Commission on the Effects of Atomic Radiation (UNSCEAR). Even though the current exposure of members of the public to natural radiation is not critical, the situation could change abruptly when mining starts.

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From raw materials to NORM by-products

Cited by 18 publications

References 88 publications

New Approach for the Determination of Radiological Parameters on Hardened Cement Pastes with Coal Fly Ash

New Approach for the Determination of Radiological Parameters on Hardened Cement Pastes with Coal Fly Ash

NORM waste, cements, and concretes. A review

Indoor Radon Measurements Using Radon Track Detectors and Electret Ionization Chambers in the Bauxite-Bearing Areas of Southern Adamawa, Cameroon

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