TY - JOUR
T1 - A comparative bio-oxidative leaching study of synthetic U-bearing minerals
T2 - Implications for mobility and retention
AU - Yang, Yi
AU - Ram, Rahul
AU - McMaster, Scott A.
AU - Pownceby, Mark I.
AU - Chen, Miao
PY - 2021/2/5
Y1 - 2021/2/5
N2 - In this study, the effects of bio-oxidative leaching on several synthetic uranium minerals – Uraninite [UO2], Pitchblende [U3O8], Coffinite [USiO4], Brannerite [UTi2O6] and Betafite [(U,Ca)2(Ti,Nb,Ta)2O7]) compared to chemical leaching in the presence of pyrite was investigated. In all cases, bio-oxidative leaching was faster and increased overall %U extraction compared to chemical leaching. The results indicated that the bio-oxidative leachability of the uranium minerals was in the order: pitchblende≈ uraninite > coffinite>> brannerite > betafite. The leaching of pitchblende and uraninite was fast and complete; U extraction from coffinite was slower over 28 days’ during the bioleaching. The use of thermophiles doubled the recovery of U from refractory brannerite. The results highlight the significant capability of bio-leaching in the recovery of U from brannerite; both mesophilic and thermophilic bacteria was found to enhance U recovery likely through enhanced breakdown of the titanate structure. Brannerite is often found in significant quantities within ore tailings due to its refractory nature, which can lead to subsequent release of U into the environment. Conversely, betafite is highly stable in the presence of mesophile and moderate thermophiles, which suggested that betafite materials can be a viable future host for long term storage for spent nuclear fuels.
AB - In this study, the effects of bio-oxidative leaching on several synthetic uranium minerals – Uraninite [UO2], Pitchblende [U3O8], Coffinite [USiO4], Brannerite [UTi2O6] and Betafite [(U,Ca)2(Ti,Nb,Ta)2O7]) compared to chemical leaching in the presence of pyrite was investigated. In all cases, bio-oxidative leaching was faster and increased overall %U extraction compared to chemical leaching. The results indicated that the bio-oxidative leachability of the uranium minerals was in the order: pitchblende≈ uraninite > coffinite>> brannerite > betafite. The leaching of pitchblende and uraninite was fast and complete; U extraction from coffinite was slower over 28 days’ during the bioleaching. The use of thermophiles doubled the recovery of U from refractory brannerite. The results highlight the significant capability of bio-leaching in the recovery of U from brannerite; both mesophilic and thermophilic bacteria was found to enhance U recovery likely through enhanced breakdown of the titanate structure. Brannerite is often found in significant quantities within ore tailings due to its refractory nature, which can lead to subsequent release of U into the environment. Conversely, betafite is highly stable in the presence of mesophile and moderate thermophiles, which suggested that betafite materials can be a viable future host for long term storage for spent nuclear fuels.
KW - Betafite
KW - Bio-oxidative leaching
KW - Brannerite
KW - Coffinite
KW - Pitchblende
KW - Uraninite
UR - http://www.scopus.com/inward/record.url?scp=85091205793&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2020.123914
DO - 10.1016/j.jhazmat.2020.123914
M3 - Article
AN - SCOPUS:85091205793
VL - 403
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
M1 - 123914
ER -