A preliminary discussion on the bio-metallogenesis of Tl deposits in the low-temperature minerogenetic province of southwestern China

Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.

地表水中Tl+的光致化学氧化

铊的价态影响铊的毒性以及铊的迁移特性,本工作研究了光照对Tl ( Ⅰ) 的氧化作用. 结果表明,pH 值低、光照强度大以及UVB 和UVC 区有利于Tl ( Ⅰ) 的氧化. pH = 2 时,汞弧灯照射10 min 后,原溶液中所剩的Tl ( Ⅰ) 不到1 %;而pH = 9 时,光照1h 后溶液中的Tl ( Ⅰ) 还剩83 %;汞弧灯照射5min 后,灯2液距离为20cm 的实验,溶液中Tl ( Ⅰ) 仅剩4 % ,而灯2液距离为36cm 时,溶液中的Tl ( Ⅰ) 还剩50 %左右;经滤光后的汞弧灯照射后,溶液中所剩的Tl ( Ⅰ) 还剩90 %左右,而未经滤光的汞弧灯照射后,溶液中所剩的Tl ( Ⅰ) 不足1 %;微生物作用在本实验条件下,相对于光氧化作用并不明显,除去微生物和未除去微生物的水样,经日光照射后,所剩的Tl ( Ⅰ) 均为70 %左右.

[Howard] Baker, gagnant [du] saut en hauteur, Anvers [en réalité 6e des Jeux olympiques d'Anvers, 17/8/20] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 60595

Discours de M. Flaherty [en réalité M. Larkin, directeur des Chevaliers de Colomb, lors de l'inauguration de la statue de La Fayette, Metz, 21/8/20] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 60621