@article{fdi:010079422,
  title = {{T}he role of barite in the post-mining stabilization of radium-226 : a modeling contribution for sequential extractions},
  author = {{B}esancon, {C}. and {C}hautard, {C}. and {B}eaucaire, {C}. and {S}avoye, {S}. and {S}ardini, {P}. and {G}{\'e}rard, {M}artine and {D}escostes, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}arite is ubiquitous and known to incorporate(226){R}a through the formation of a solid-solution. {I}n {U} mining mill tailings, barite is one of the dominant sulfate-binding minerals. {I}n such environments, sequential extractions are generally used to identify the {U}- and(226){R}a-binding phases and their associated reactivity. {T}o better decipher the main processes governing the behavior of(226){R}a during such sequential extractions, a geochemical model was developed with {PHREEQC} mimicking the sequential extraction of {U} and(226){R}a from {B}ois-{N}oirs {L}imouzat {U} mine tailings, {F}rance. {T}he model results were compared with a dataset produced by an experimental sequential extraction from the same mine tailings and including data on the solids and selective extraction results with the major elements, {U} and(226){R}a. {T}he simulations reproduced the results of the experimental chemical extractions accurately, with iron oxyhydroxides being the major {U} binding phase. {H}owever, the modeling indicated rather that barite would be the main(226){R}a binding phase, instead of the iron oxyhydroxides identified by the experimental extractions. {T}his is consistent with the(226){R}a concentration measured in pore water, but in disagreement with the direct interpretation of the sequential extractions. {T}he direct interpretation disregarded the role of barite in the geochemical behavior of(226){R}a because barite was not specifically targeted by any of the extraction steps. {H}owever, the modeling showed that the dissolution of(226){R}a-binding barite by reactants would lead to a(226){R}a redistribution among the clay minerals, resulting in a skew in the experimental results. {S}imilar results were achieved by referring simply to the bulk mineralogy of the tailings. {T}his study highlights the importance of considering the mineralogy, mineral reactivity and retention capacity for more realistic interpretation of sequential extractions. {M}oreover, this paper provides new perspectives on the long-term consequences of these mill tailings in which barite controls the geochemical behavior of the(226){R}a.},
  keywords = {sequential extractions ; {U} and(226){R}a modeling ; barite ; uranium mill ; tailings ; {FRANCE}},
  booktitle = {},
  journal = {{M}inerals},
  volume = {10},
  numero = {6},
  pages = {art. 497 [21 p.]},
  year = {2020},
  DOI = {10.3390/min10060497},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079422},
}