Tunable formation of copper metal, oxide, chloride and hydroxyl chloride nanoparticles from aqueous copper solutions using nanoscale zerovalent iron particles

Richard Crane,Devin Sapsford

doi:10.1177/1847980419886173

Abstract

The influence of different parameters (solid–liquid ratio, initial pH, initial Cu concentration and anion type) on the cementation of aqueous copper (Cu) with nanoscale zerovalent iron (nZVI) has been studied. The work has been established to study both the influence such parameters have on the kinetics and efficacy of the cementation process but also the physicochemical composition of resultant Cu-bearing products. The nZVI exhibited high Cu removal capacity (maximum removal 905.2 mg/g) due to its high surface area. X-ray diffraction determined the most common Cu-bearing precipitates were Cu2O, CuCl2 and Cu2(OH)3Cl for solutions containing Cl− counterions (CuCl2 salt precursor), while Cu0 and Cu2O were the most common phases for those containing [Formula: see text] counterions (CuSO4 salt precursor). Transmission electron microscopy determined such precipitates were discrete nanoparticles of relatively high purity Cu (e.g. >80 wt% Cu or ≥99.9 wt% Cu and O). Overall the results demonstrate nZVI as effective for the one-pot transformation of aqueous Cu into a range of different high purity Cu-bearing nanoparticles. The methodology developed herein is therefore likely to have important application in the recovery of Cu from wastewater and process solutions where the direct upcycling to high-value Cu-bearing nanoparticles is an advantageous form in which to recover Cu.

Highlights

Copper (Cu) remains a valuable commodity due to its widespread use in a range of different industrial and domestic products and processes
TEM analysis determined that the nanoscale zerovalent iron (nZVI) were spherical, generally within an approximate size range of 10–150 nm and an average diameter of 61 nm (Figure 1)
Dark mottles were recorded within the metallic cores which indicate that individual particles are either polycrystalline or comprised of isolated metal crystals in an otherwise amorphous matrix

Summary

Introduction

Copper (Cu) remains a valuable commodity due to its widespread use in a range of different industrial and domestic products and processes (electric circuitry, transportation, metallurgy, construction, medicine, petroleum refining, etc.). The concurrent global transition towards a circular economy means that there is strong current demand for the development of new processes that can be used to recover Cu during hydrometallurgical processing. Nanomaterials and Nanotechnology which to capture aqueous Cu when it is present as a component of wastewaters and effluents, for example, those derived from mining, processing and disposal of Cu.[1] whilst Cu is an essential trace element exposure to excess Cu is known to cause a wide range of health and environmental issues, with permissible limits given by the World Health Organisation (WHO) for dissolved Cu in drinking water currently 2 mg/L2 and contamination of water resources with Cu a significant global environmental problem. The development of reliable and cost-effective methods for the removal/capture of Cu from wastewaters and effluents is an important technical challenge for environmental protection and prevention of Cu ‘leakage’ from the materials loop

Methods

Results

Conclusion