Distribution, characterization, and geochemical controls of elements of concern in uranium mine tailings, Key Lake, Saskatchewan, Canada

Microscale mineralogical characterization of As, Fe, and Ni in uranium mine tailings

“…In general, the high-grade McArthur River ores contain significantly less Ni, Co, and As-bearing sulfide minerals than the Deilmann ore (Jamieson and Frost, 1997). The geochemistry of the solid tailings in the DTMF reflects the changes in ore composition to the mill feeds (Shaw et al, 2011).…”

“…Samples were chosen from different depths (to represent tailings solids from the different ore bodies milled) and were spatially distributed throughout the DTMF (Table 1). The detailed geochemistry of the tailings, including methodologies for sampling and storage, chemical (including statistical) analysis as well as the location of core holes in the tailings facility are detailed in Shaw et al (2011). The solid samples were air-dried, impregnated with epoxy to form cylindrical plugs, and allowed to harden at room temperature for approximately two weeks.…”

“…Geochemical studies associated with extensive drilling and sampling programs on tailings from the Key Lake TMF, located in northern Saskatchewan, over nearly two decades have resulted in detailed temporally-and spatially-related chemical profiles (Shaw et al, 2011). Bulkscale chemical analyses have also been carried out on solids and aqueous separates from drill core samples approximately 20-50 cm in length.…”

Fate of adsorbed arsenate during phase transformation of ferrihydrite in the presence of gypsum and alkaline conditions

“…These tailings are alkaline and oxic (mean pH 9.8; mean Eh +200 mV) with an ambient temperature of 1-2°C (Shaw et al, 2011). Mean Ca 2+ and SO 4 2− concentrations in the porewaters are~600 and~1500 mg/L, respectively, and Fe/As molar ratios of solid samples from the two tailings bodies in the DTMF are~52 and~10 (Shaw et al, 2011). Ferrihydrite is highly stable under the pH conditions and Fe/As ratios present at the DTMF (Das et al, 2011b).…”

“…The U tailings from the Key Lake mill have been deposited in the Deilmann Tailings Management Facility (DTMF) since 1996. These tailings are alkaline and oxic (mean pH 9.8; mean Eh +200 mV) with an ambient temperature of 1-2°C (Shaw et al, 2011). Mean Ca 2+ and SO 4 2− concentrations in the porewaters are~600 and~1500 mg/L, respectively, and Fe/As molar ratios of solid samples from the two tailings bodies in the DTMF are~52 and~10 (Shaw et al, 2011).…”