Chelating polymers with valuable sorption potential for development of precious metal recycling technologies

Abstract

A special attention is currently focused on the recovery of Au, Ag, Pt, Pd and Rh from both primary and secondary sources. From the wide range of sorbents that have been used in this respect, the required selectivity is proved only by the chelating polymers containing donor N, O and S atoms in their functional groups. This work presents the recent published researches on this topic, pointing out the capabilities of chelating sorbents based on organic synthetic polymers for a sustainable development. The chelating sorbents are differentiated and reviewed according to their synthesis strategy and compatibility with synthetic and real matrices. First, an overview on the novel functionalized polymers and impregnated resins with good selectivity for the recovery of most valuable precious metals from synthetic leach solutions is given. Subsequently, the performances of these materials in the selective and preconcentrative recovery of Au, Ag, Pt, Pd and Rh from simulated and real leachates are discussed. The viability of an integrated approach for the determination of precious metals from simulated solutions by solid phase spectrometry is highlighted. The transposition of chelating polymers’ potential in challenging technologies for precious metal recovery-reuse-recycling needs further research on directions that are proposed.

Multicomponent System of Single‐Walled Carbon Nanotubes Functionalized with a Melanin‐Inspired Material for Optical Detection and Scavenging of Metals

“…[ 1,4 ] Most metal‐ion‐scavengers are based on the complexation of metal‐ions with a molecule or a polymer bearing chelating groups, or by DNA‐aptamers forming metal‐specific binding sites. [ 3,5,6 ] Many metal‐binding molecules have high complexity, posing a challenge to their synthesis, [ 3,6 ] while biological materials like DNA‐aptamers, on the other hand, can easily suffer from biodegradation during in vivo applications. [ 7 ]…”

“…[1,4] Most metal-ion-scavengers are based on the complexation of metal-ions with a molecule or a polymer bearing chelating groups, or by DNA-aptamers forming metal-specific binding sites. [3,5,6] Many metal-binding molecules have high complexity, posing a challenge to their synthesis, [3,6] while biological materials like DNA-aptamers, on the other hand, can easily suffer from biodegradation during in vivo applications. [7] Melanins are natural pigments that have a range of protective functionalities, including photoprotection, and they also have the capacity to bind and release metalions, particularly transition metal-ions.…”

Thiourea resole polymers for recovery of noble element

“…) are widely used in different sectors (electronics, jewelry, medicine and catalysis) due to their specific physical and chemical properties. Related to their increasing demand and the limitations of the primary nonrenewable sources, the recovery of precious elements from industrial waste has attracted the attention of many researchers from the perspective of both economics and environmental protection (Bigum et al, 2017;Das, 2010;Ding et al, 2019;Tofan & Wenkert, 2022). In addition, the industrial wastewater has been classified as a potential secondary source of noble ions whose concentration is typically much higher than the very low concentration found in the primary source (Hasegawa et al, 2018;Zhang & Xu, 2016).…”

“…To recover precious elements from wastewater, industrial techniques including the pyrometallurgical and hydrometallurgical processes have been widely applied (Cyganowski, 2020;Das, 2010). The hydrometallurgical process has been used more frequently for reasons related to its advantages of being relatively inexpensive, requiring low temperature conditions, being efficient, readily available, adaptable, and presenting high metal extraction efficiencies (Ding et al, 2019;Quinet et al, 2005;Tofan & Wenkert, 2022). Currently, there is a viable interest in the recovery of metals using the standard separation processes, such as precipitation, ion exchange, liquid-liquid extraction, membrane filtration, and solid-liquid extraction, specifically adsorption (Ding et al, 2019;Ramesh et al, 2008).…”

Sustainable and Selective Modern Methods of Noble Metal Recycling

“…Different metal species can also be differentiated based on selective coordination and paired with selective partitioning to different media (c). Selective extraction, [19] membrane transfer, [20] trapping to polymers, solid carriers, frameworks, and materials [21][22][23] or even selective (co-)precipitation of metal salts [24] are all coordinative separation techniques. Clearly, sustainable approaches can be introduced at different stages of hydrometallurgical treatment but utilization of safe, affordable and sustainable ligands, oxidants, reducing agents and other additives are essential for the progression of this field.…”