Geochemistry, Mineralogy and Microbiology of Cobalt in Mining-Affected Environments

Abstract

Cobalt is recognised by the European Commission as a “Critical Raw Material” due to its irreplaceable functionality in many types of modern technology, combined with its current high-risk status associated with its supply. Despite such importance, there remain major knowledge gaps with regard to the geochemistry, mineralogy, and microbiology of cobalt-bearing environments, particularly those associated with ore deposits and subsequent mining operations. In such environments, high concentrations of Co (up to 34,400 mg/L in mine water, 14,165 mg/kg in tailings, 21,134 mg/kg in soils, and 18,434 mg/kg in stream sediments) have been documented. Co is contained in ore and mine waste in a wide variety of primary (e.g., cobaltite, carrolite, and erythrite) and secondary (e.g., erythrite, heterogenite) minerals. When exposed to low pH conditions, a number of such minerals are known to undergo dissolution, typically forming Co2+(aq). At circumneutral pH, such aqueous Co can then become immobilised by co-precipitation and/or sorption onto Fe and Mn(oxyhydr)oxides. This paper brings together contemporary knowledge on such Co cycling across different mining environments. Further research is required to gain a truly robust understanding of the Co-system in mining-affected environments. Key knowledge gaps include the mechanics and kinetics of secondary Co-bearing mineral environmental transformation, the extent at which such environmental cycling is facilitated by microbial activity, the nature of Co speciation across different Eh-pH conditions, and the environmental and human toxicity of Co.

Hydrogeochemical Response of a Variably Saturated Sulfide‐Bearing Mine Waste‐Rock Pile to Precipitation: A Field‐Scale Study in the Discontinuous Permafrost Region of Northern Canada

“…Ziwa et al. (2021) concluded that Co mobility in mine wastes is typically controlled by precipitation and co‐precipitation as hydroxides and sulfates. These processes may contribute to Co mobility in Faro waste‐rock pile; however, the secondary mineralogical control on Co mobility is the subject of an ongoing assessment.…”

“…Bao et al (2021) found that Pb mobility is largely retained due to formation of Pb-bearing carbonates (i.e., cerussite, and shannonite) in the waste-rock pile. Ziwa et al (2021) concluded that Co mobility in mine wastes is typically controlled by precipitation and co-precipitation as hydroxides and sulfates. These processes may contribute to Co mobility in Faro waste-rock pile; however, the secondary mineralogical control on Co mobility is the subject of an ongoing assessment.…”

Molybdenum background and pollution levels in the Taipu River, China

“…The environmental pollution and risks of Mo area around mines have been heavily reported (Timofeev et al 2018;Song et al 2021). In non-mining areas, abnormally high Mo concentration in soils and aquatic system was found as a result of iron, alloys, ceramics, catalysts, lubricants and pigments production and agricultural fertilization (Smedley et al 2017;Ziwa et al 2020). The specific use of Mo in stainless steel is 1.1-2.9 kg/t worldwide (Outteridge et al 2019).…”

Evaluación de la peligrosidad de los elementos potencialmente tóxicos presentes en residuos mineros abandonados

“…(hydroxocobalamina) [54], la exposición excesiva al Co puede derivar en una amplia gama de afectaciones a la salud humana, tales como, el bocio y la reducción de la actividad tiroidea [55]. Este elemento se encuentra contenido en una gran variedad de residuos mineros procedentes de yacimientos de cobaltita (CoAsS), cattierita (CoS2), carrolita ((CuCo)2S4), sphaerocobaltita (CoCO3), cobaltpentlandita ((Co-Fe)9S8), siegenita ((Ni,Co)3S4), linnaeita (CoS4), esmaltita (CoAs2), safflorita ((Co,Fe)As2) y escuterudita ((Co,Fe,Ni)As2-3).…”

“…Este elemento se encuentra contenido en una gran variedad de residuos mineros procedentes de yacimientos de cobaltita (CoAsS), cattierita (CoS2), carrolita ((CuCo)2S4), sphaerocobaltita (CoCO3), cobaltpentlandita ((Co-Fe)9S8), siegenita ((Ni,Co)3S4), linnaeita (CoS4), esmaltita (CoAs2), safflorita ((Co,Fe)As2) y escuterudita ((Co,Fe,Ni)As2-3). En condiciones bajas de pH estos minerales pueden disolverse y formar Co 2+ acuoso, mientras que, a un pH neutro, este Co acuoso puede inmovilizarse por precipitación y/o sorción en oxhidróxidos u óxidos de Fe y Mn [55].…”