A cross scale investigation of galena oxidation and controls on mobilization of lead in mine waste rock

JOURNAL OF HAZARDOUS MATERIALS

卷:412

Article

Bao, Zhongwen¹  Al, Tom²  Couillard, Martin³  Poirier, Glenn⁴  Bain, Jeff¹  Shrimpton, Heather K.¹  Finfrock, Y. Zou^5,6  Lanzirotti, Antonio⁷  Paktunc, Dogan⁸  Saurette, Emily¹  Hu, Yongfeng⁵  Ptacek, Carol J.¹  Blowes, David W.¹ 

[1] Univ Waterloo, Dept Earth & Environm Sci, 200 Univ Ave West, Waterloo, ON N2L 3G1, Canada

[2] Univ Ottawa, Dept Earth & Environm Sci, 75 Laurier Ave East, Ottawa, ON K1N 6N5, Canada

[3] Natl Res Council Canada, Energy Min & Environm Portfolio, 1200 Montreal Rd, Ottawa, ON K1A 0R6, Canada

[4] Canadian Museum Nat, Ottawa, ON K1P 6P4, Canada

[5] Canadian Light Source Inc, Sci Div, 44 Innovat Blvd, Saskatoon, SK S7N 2V3, Canada

[6] Argonne Natl Lab, Adv Photon Source, CLS APS Sect 20,9700 S Cass Ave, Argonne, IL 60439 USA

[7] Univ Chicago, Ctr Adv Radiat Sources, Chicago, IL 60637 USA

[8] Nat Resources Canada, Canmet Min, 555 Booth St, Ottawa, ON K1A 0G1, Canada

关键词: Galena;    Covellite;    Cerussite;    Pb mobility;    Mine waste rock;   

DOI  :  10.1016/j.jhazmat.2021.125130

来源: Elsevier

【 摘 要 】

Galena and Pb-bearing secondary phases are the main sources of Pb in the terrestrial environment. Oxidative dissolution of galena releases aqueous Pb and SO4 to the surficial environment and commonly causes the formation of anglesite (in acidic environments) or cerussite (in alkaline environments). However, conditions prevalent in weathering environments are diverse and different reaction mechanisms reflect this variability at various scales. Here we applied complementary techniques across a range of scales, from nanometers to 10 s of meters, to study the oxidation of galena and accumulation of secondary phases that influence the release and mobilization of Pb within a sulfide-bearing waste-rock pile. Within the neutral-pH pore-water environment, the oxidation of galena releases Pb ions resulting in the formation of secondary Pb-bearing carbonate precipitates. Cerussite is the dominant phase and shannonite is a possible minor phase. Dissolved Cu from the pore water reacts at the surface of galena, forming covellite at the interface. Nanometer scale characterization suggests that secondary covellite is intergrown with secondary Pb-bearing carbonates at the interface. A small amount of the S derived from galena is sequestered with the secondary covellite, but the majority of the S is oxidized to sulfate and released to the pore water.

【 授权许可】

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