Schwertmannite and hydrobasaluminite: A re-evaluation of their solubility and control on the iron and aluminium concentration in acidic pit lakes

Daily Freeze–Thaw Cycles Affect the Transport of Metals in Streams Affected by Acid Drainage

“…It is also known that in natural systems Fe(OH) 3 (a) becomes saturated at pH > 3 and that aluminum hydroxide precipitates at pH > 4.5 [42]. Although there are other iron and aluminum phases involved (such as hydrosulfates [43]), the analysis is consistent with how turbidity simultaneously increases with pH. These increases in turbidity downstream are not caused by incoming of suspended solids from upstream of the confluence.…”

“…One hundred percent of turbidity values measured downstream were higher than 4 NTU (69% were higher than 14 NTU), indicating that turbidity increases were mainly due to pH-dependent chemical reactions. aluminum phases involved (such as hydrosulfates [43]), the analysis is consistent with how turbidity simultaneously increases with pH. These increases in turbidity downstream are not caused by incoming of suspended solids from upstream of the confluence.…”

“…Downstream pH triggers the precipitation of iron and aluminum mineral phases at streams affected by acid drainage [42,43,46]. In consequence, diurnal cycles in the formation of iron and aluminum phases, known to control the cycling of arsenic in the environment [23,42,43,[46][47][48], also constitute an important factor in the fate and transport of this toxic element.…”

An investigation of acidic head-water streams in the Judith Mountains, Montana, USA

“…S5 and S6, Supplemental Files), the stream waters in these middle reaches are closer to equilibrium with basaluminite as opposed to amorphous Al(OH) 3 . Basaluminite has recently been shown to be an important control on the mobility of Al in acidic, sulfate-rich waters, including mining pit lakes (Sánchez-España et al, 2011) and acid sulfate soils (Jones et al, 2011). However, more detailed solids characterization is needed to verify the mineralogy of the white precipitates in this study.…”

Precipitation of aluminum and magnesium secondary minerals from uranium mill raffinate (pH 1.0–10.5) and their controls on aqueous contaminants

“…Thus, the objectives of this study were to: (1) define the secondary Al and Mg minerals that precipitate during bulk neutralization of U mill raffinate and their mineralogical control(s) on As, Se, Mo, and Ni and (2) quantify the geochemical controls exerted by the Al and Mg minerals with respect to the sequestration of As(V), Se(IV), and Mo(VI). Objective (1) was attained using synthetic raffinate of varying compositions in a validated continuous flow lab-scale model of the KL process (Robertson et al, 2014). The mineralogy of the SeeMo and Lamella underflow solids and their final mixed form from the lab-model were studied using XRD, Al K-edge X-ray absorption spectroscopy (XAS), and transmission electron microscopy (TEM) elemental mapping.…”