Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods

Santos, Adir Janete Godoy dos; Mazzilli, B. P.; Fávaro, D. I. T.; Silva, Paulo Sérgio Cardoso da

doi:10.1016/j.jenvrad.2005.10.008

Cited by 99 publications

(48 citation statements)

References 8 publications

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“…For example, it would be beneficial to change the dissolution acid from sulfuric acid, which produces phosphogypsum as a waste product, to hydrochloric acid. This would alleviate processing a second solid for recovery of the REY partitioned into the phosphogypsum phase (e.g., [6,8]). Production of REY as a byproduct or co-product of phosphate mining needs to be considered in the early stages of planning for a new terrestrial or marine mining operation.…”

Section: Introductionmentioning

confidence: 99%

Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

et al. 2016

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Abstract:Marine phosphorites are known to concentrate rare earth elements and yttrium (REY) during early diagenetic formation. Much of the REY data available are decades old and incomplete, and there has not been a systematic study of REY distributions in marine phosphorite deposits that formed over a range of oceanic environments. Consequently, we initiated this study to determine if marine phosphorite deposits found in the global ocean host REY concentrations of high enough grade to be of economic interest. This paper addresses continental-margin (CM) and open-ocean seamount phosphorites. All 75 samples analyzed are composed predominantly of carbonate fluorapatite and minor detrital and authigenic minerals. CM phosphorites have low total REY contents (mean 161 ppm) and high heavy REY (HREY) complements (mean 49%), while seamount phosphorites have 4-6 times higher individual REY contents (except for Ce, which is subequal; mean ΣREY 727 ppm), and very high HREY complements (mean 60%). The predominant causes of higher concentrations and larger HREY complements in seamount phosphorites compared to CM phosphorites are age, changes in seawater REY concentrations over time, water depth of formation, changes in pH and complexing ligands, and differences in organic carbon content in the depositional environments. Potential ore deposits with high HREY complements, like the marine phosphorites analyzed here, could help supply the HREY needed for high-tech and green-tech applications without creating an oversupply of the LREY.

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Section: Introductionmentioning

confidence: 99%

Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

et al. 2016

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“…These impurities can percolate through the pile and contaminate groundwater, eventually causing damage to human health (Mazzilli et al, 2000). Another problem is 222 Rn exhalation, which can affect people in the surroundings of the storage sites (Santos et al, 2006), especially workers.…”

Section: Introductionmentioning

confidence: 99%

Radionuclides and heavy metal contents in phosphogypsum samples in comparison to cerrado soils

Jacomino

Oliveira²,

Taddei

et al. 2009

Rev. Bras. Ciênc. Solo

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Phosphogysum (PG) or agricultural gypsum, a solid waste from the phosphate fertilizer industry, is used as soil amendment, especially on soils in the Cerrado region, in Brazil. This material may however contain natural radionuclides and metals which can be transferred to soils, plants and water sources. This paper presents and discusses the results of physical and chemical analyses that characterized samples of PG and compares them to the results found in two typical soils of the Cerrado, a clayey and sandy one. These analyses included: solid waste classification, evaluation of organic matter content and of P, K, Ca, Mg, and Al concentrations and of the mineralogical composition. Natural radionuclides and metal concentrations in PG and soil samples were also measured. Phosphogypsum was classified as Class II A -Not Dangerous, Not Inert, Not Corrosive and Not Reactive. The organic matter content in the soil samples was low and potential acidity high. In the mean, the specific 226 Ra activity in the phosphogypsum samples (252 Bq kg -1 ) was below the maximum level recommended by USEPA, which is 370 Bq kg -1 for agricultural use. In addition, this study verified that natural

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“…Phosphate rocks, for instance, might be from sedimentary or igneous origin, the former showing higher concentrations of 238 U, while the latter shows higher concentrations of 232 Th. In Brazil, 80% of the phosphate rock used in the industry for phosphoric acid production comes from igneous origin (Canut, 2006 Ra (Mazzilli et al, 2000;Silva et al, 2001;Saueia et al, 2005;Santos et al, 2006).…”

Section: Resultsmentioning

confidence: 99%

“…Both Ra elements have a biological behavior similar to Ca deposited in mammal bones (Choppin & Rydberg, 1980) The presence of radionuclides has generated discussions on the impact of PG on human health (Ettenhuber & Lehmann, 1986), and its use in agriculture is restricted by certain countries. In the USA, the maximum limit of 226 Ra in PG was set as 370 Bq kg -1 (United States Environmental Protection Agency, 1998 Despite the various studies found in the literature on the use of PG in agriculture (Hull & Burnett, 1996;Burnett & Elzerman, 2001;Beddow et al, 2006;Papastefanou et al, 2006;Abril et al, 2008Abril et al, , 2009, there are only few studies on the presence of radionuclides in PG produced in Brazil (Silva, 2001;Silva et al, 2001;Saueia et al, 2005;Santos et al, 2006;Jacomino et al, 2009). Moreover, there is very little information available on the addition of radionuclides through PG application in Brazilian agriculture (Parreira et al, 2001;Dias et al, 2010), mainly in the regions where the no-till farming predominates, as the South of Brazil.…”

Section: Introductionmentioning

confidence: 99%

Radiological impact of phosphogypsum surface application in a no-till system in Southern Brazil

Dias

Caires²,

Pires

et al. 2010

Pesq. agropec. bras.

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Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods

Cited by 99 publications

References 8 publications

Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

Radionuclides and heavy metal contents in phosphogypsum samples in comparison to cerrado soils

Radiological impact of phosphogypsum surface application in a no-till system in Southern Brazil

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