Assessment of the geoavailability of trace elements from selected zinc minerals

Abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Suggested citation: Driscoll, R.L., Hageman, P.L., Benzel, W.M., Diehl, S.F., Morman, Suzette, Choate, L.M., and Lowers, Heather, 2014, Assessment of the geoavailability of trace elements from selected zinc minerals: U.S. Geological Survey Open-File Report 2013-1309. ISSN 2331ISSN -1258 Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. AbstractThis assessment focused on five zinc-bearing minerals. The minerals were subjected to a number of analyses including quantitative X-ray diffraction, optical microscopy, leaching tests, and bioaccessibility and toxicity studies. Like a previous comprehensive assessment of five copper-bearing minerals, the purpose of this assessment was to obtain structural and chemical information and to characterize the reactivity of each mineral to various simulated environmental and biological conditions. As in the copper minerals study, analyses were conducted consistent with widely accepted methods. Unless otherwise noted, analytical methods used for this study were identical to those described in the investigation of copper-bearing minerals.Two sphalerite specimens were included in the zinc-minerals set. One sphalerite was recovered from a mine in Balmat, New York; the second came from a mine in Creede, Colorado. The location and conditions of origin are significant because, as analyses confirmed, the two sphalerite specimens are quite different. For example, data acquired from a simulated gastric fluid (SGF) study indicate that the hydrothermally formed Creede sphalerite contains orders of magnitude higher arsenic, cadmium, manganese, and lead than the much older metamorphic Balmat sphalerite. The SGF and other experimental results contained in this report suggest that crystallizing conditions such as temperature, pressure, fluidization, or alteration processes significantly affect mineral properties-properties that, in turn, influence reactivity, solubility, and toxicity.The three remaining minerals analyzed for this report-smithsonite, hemimorphite, and hydrozincite-are all secondary minerals or alteration products of zinc-ore deposits. In addition, all share physical characteristics such as tenacity, density, streak, and cleavage. Similarities end there. The chemical composition, unit-cell parameters, acid-neutralizing potential, and other observable and quantifiable properties indic...

Geochemical and biological controls on the ecological relevance of total, dissolved, and colloidal forms of trace elements in large boreal rivers: review and case studies

“…As structures become more crystalline over time, the TEs become more strongly associated with the mineral structure and tend to be less prone to release, making them less environmentally available and bioaccessible; however, other factors such as surface area and aggregation also play important roles ( Fig. 7; Kostka et al 1999;Driscoll et al 2013). Colloidal carriers also adsorb other TEs and DOM onto their surfaces, with complex and as yet poorly defined implications for mobility and bioavailability (Smith 1999;Warren and Haack 2001;Buffle et al 2009;Van Leeuwen and Buffle 2009).…”