Recovery of Rare Earth Elements and Yttrium from Passive-Remediation Systems of Acid Mine Drainage

Abstract

Rare earth elements and yttrium (REY) are raw materials of increasing importance for modern technologies, and finding new sources has become a pressing need. Acid mine drainage (AMD) is commonly considered an environmental pollution issue. However, REY concentrations in AMD can be several orders of magnitude higher than in naturally occurring water bodies. With respect to shale standards, the REY distribution pattern in AMD is enriched in intermediate and valuable REY, such as Tb and Dy. The objective of the present work is to study the behavior of REY in AMD passive-remediation systems. Traditional AMD passive remediation systems are based on the reaction of AMD with calcite-based permeable substrates followed by decantation ponds. Experiments with two columns simulating AMD treatment demonstrate that schwertmannite does not accumulate REY, which, instead, are retained in the basaluminite residue. The same observation is made in two field-scale treatments from the Iberian Pyrite Belt (IPB, southwest Spain). On the basis of the amplitude of this process and on the extent of the IPB, our findings suggest that the proposed AMD remediation process can represent a modest but suitable REY source. In this sense, the IPB could function as a giant heap-leaching process of regional scale in which rain and oxygen act as natural driving forces with no energy investment. In addition to having environmental benefits of its treatment, AMD is expected to last for hundreds of years, and therefore, the total reserves are practically unlimited.

Application of nanofiltration for acidic waters containing rare earth elements: Influence of transition elements, acidity and membrane stability

“…power generation, X-ray imaging, fibre 36 optics, among others) [2]. Although REEs are found in a minor proportion compared to the above-mentioned 37 transition metals, their concentration is relatively high (two orders of magnitude higher than the one presented in 38 natural waters) [3,4]. One of the largest sulphide ore deposits in the world is located in the Iberian Pyrite Bell 39 (IPB), which is situated in the Southern Iberian Peninsula.…”

Bio-Electrochemical process for Metal and Sulfur Recovery from Acid Mine Drainage

“…, which is several orders of magnitude higher than in naturally occurring water bodies (Stewart et al 2017;Ayora et al 2016;Merten et al 2005). …”

“…A strong association between high REE concentrations and acidity has been described in surface and ground water (Welch et al 2009;Noack, Dzombak & Karamalidis 2014). Recently, Ayora et al 2016 reported that REY content in AMD can be several orders of magnitude higher than in naturally occurring water bodies.…”

“…A schematic overview of the generation of AMD is presented in Figure 2.2. Upon exposure to oxygen and water, communities of autotrophic and heterotrophic archaea and bacteria catalyze iron and sulfur oxidation, thus may ultimately determine the rate of release of a waste streams with very specific characteristics (Baker & Banfield 2003 , which is several orders of magnitude higher than in naturally occurring water bodies (Stewart et al 2017;Ayora et al 2016;Merten et al 2005;Parbhakar-Fox et al 2014 The increasing number of abandoned and remote mine sites represents a significant threat from soil and waterways contamination due to significant management issues associated with AMD (Favas et al 2016). In Australia, there are over 50,000…”

“…The problem of AMD offers attractive opportunities for water recycling and resource recovery, with direct benefits for the environment and the operational and economic viability of the mining operations (Simate & Ndlovu 2014;Wang, Bejan & Nigel J. Bunce 2003;Sahinkaya et al 2009;Ayora et al 2016;Tabak et al 2003). The increasing demand of REY as a critical material for modern technological developments has encouraged exploration for other potential sources (Massari & Ruberti 2013).…”