| Selective recovery of precious metals has always been a major challenge to researchers, with significant impact on the Canadian economy and that of Northern Ontario especially. Thus, mining companies are highly invested in the extraction and refining of these valuable elements. This research aims to exploit a nanotechnologically-designed adsorbent (denoted MP-HMS) to extract and separate precious metals from ultra-low concentration solutions. Adsorption tests were conducted on simulated solutions containing precious metal ions and ubiquitous transition metals found in typical mine effluents (Cu, Ni and Zn). The affinity of the adsorbent towards metal ions under varying concentrations and electrochemical reducing conditions was assessed. The materials showed distinctive binding selectivity towards precious metals under different reducing conditions. Precious metal ions were selectively recovered in a mixed ion solutions such as those of typical mine effluents, from ultra low concentration levels. Another promising and significant attribute of adsorbents is their rapid adsorption kinetics. Results obtained show that more than 60% of Rhodium ions, 53% of Ruthenium ions, 79% of palladium, 90% of silver ions, 76% of gold ions and 76% of platinum ions were adsorbed in less than 40 seconds. The efficacy of these new materials for the recovery of precious metals from ultra-low concentration solutions such as mining effluent, their distinctive binding selectivity towards precious metals under different reducing conditions and rapid adsorption kinetics make these materials most promising for a multitude of mining applications in which the precious metals recovery and the mitigation of hazardous heavy metal ions in the environment is of interest. |
