The Aqueous Geochemistry of the Rare Earth Elements and Yttrium. Part 13: REE Geochemistry of Mine Drainage from the Pine Creek Area, Coeur d'Alene River Valley, Idaho, USA

Abstract

The present study focuses on drainage from a number of abandoned mine sites (including adits and seeps from tailings piles) in the Pine Creek area (Figures 1 and 2) of Idaho, at the southern edge of the Bunker Hill Superfund Site, about 10 km south of Smelterville. With one exception, the mine drainage is neutral to slightly alkaline in pH. This is a result of the neutralization of acid produced during sulfide oxidation by the carbonate gangue minerals present in the mine workings. In spite of the generally nearneutral pH values, all the waters contain relatively high concentrations of zinc and some waters contain high concentrations of other heavy metals. We have analyzed these waters to improve our knowledge of the behavior of the REE during sulfide oxidation followed by neutralization via carbonate dissolution.