Application of semi-empirical model for the evaluation of radium activity in phosphogypsum used as component of clinker

Phosphogypsum is a residue that has been used by the cement industry as a substitute for the natural gypsum, used as a clinker additive during the production of Portland cement. There is a potential increase in this residue use since the large amount of phosphogypsum is generated as outcome of the p...

Full description

Saved in:
Bibliographic Details
Main Authors: Ricardo Rossasi Geraldo, Sergei Anatolyevich Paschuk, Rafael Carvalho Barreto, Janine Nicolosi Corrêa, Guilherme Soares Zahn, Paulo Sergio Cardoso da Silva, Amanda Claudia Malagi da Silva, Danielle Cristine Narloch, Isabelle Cabello Araujo
Format: Article
Language:English
Published: Brazilian Radiation Protection Society (Sociedade Brasileira de Proteção Radiológica, SBPR) 2021-04-01
Series:Brazilian Journal of Radiation Sciences
Subjects:
Online Access:https://bjrs.org.br/revista/index.php/REVISTA/article/view/1518
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Phosphogypsum is a residue that has been used by the cement industry as a substitute for the natural gypsum, used as a clinker additive during the production of Portland cement. There is a potential increase in this residue use since the large amount of phosphogypsum is generated as outcome of the phosphate fertilizer industries. However, phosphogypsum can be considered a source of radioactive contamination since it has 226Ra in its composition. Depending on the concentration of 226Ra, from the radiological protection point of view, this may cause a problem because this radionuclide and its direct decay product 222Rn along with other decay products, represent the largest fraction of radiation internal dose received by people. In order to evaluate the level of radiological risk that may be associated with the use of phosphogypsum, it is necessary to identify the concentration of 226Ra in building material. The aim of this research is to analyze the samples of phosphogypsum in relation to the concentrations of 226Ra, determined indirectly through 222Rn activity measurements. This measurement process has the advantage of being fast, convenient and relatively inexpensive when compared to traditional 226Ra concentration in samples measurement methods. Proposed physical-mathematical model was used to establish radium concentration from radon exhalation rate from cement mortar samples. The 222Rn activity measurements were performed with a portable detector with cubic phosphate samples with 50 mm edges each placed in a closed atmosphere of the sampling chamber until secular equilibrium is achieved. Obtained concentrations of radium activity in studied samples of phosphogypsum and cement mortars were found below the limits recommended by CNEN and international regulation.
ISSN:2319-0612