부산대학교 도서관

In this thesis, the primary focus is on the development of materials and technologies for the recovery of precious metals from urban mining waste. A novel material has been meticulously engineered, showcasing exceptional adsorption performance, acid resistance, reusability, and selectivity exclusively for precious metal ions. Additionally, a proposed solvent with selective extraction capabilities is accompanied by the formulation of a metal affinity prediction model. The research extends to the creation of an eco- friendly leaching process, positioned as an alternative to conventional highly toxic and corrosive acids and organic solvents.In Chapter 3, the exploration delves into separation studies involving palladium (Pd) or platinum (Pt) from acidic solutions. Fifteen hydrophobic ionic liquids (ILs), capable of binary phase formation with acidic aqueous solutions, are utilized. This chapter presents experimental investigations into IL separation efficiencies, along with a discussion of their properties and toxicities predicted through a previously introduced toxicity model. Results reveal that extraction efficiency for Pd and Pt is contingent on the IL type and metal concentration. Noteworthy separation efficiencies for Pt from a mixed Pd-Pt solution were observed with [IM1-1Bz][(CF3SO2)2N] and [IM16][(CF3SO2)2N]. Furthermore, quantitative structure–activity relationship models with R2 values exceeding 0.91 were developed to comprehend the partitioning mechanisms of ILs.In Chapter 4, the successful recovery of platinum group metals (Pd and Pt) from spent automobile catalysts (SACs) is detailed using a low dielectric constant ionic liquid coupled with organic acids. Systematic leaching experiments, based on varying dielectric constant values of ionic liquids, reveal a direct correlation between lower dielectric constants and heightened leaching efficiency for platinum group metals. The approach, featuring a brief leaching duration of 1 hour, demonstrates efficiencies of 95.7% for Pd and 88.3% for Pt, surpassing aqua regia, a conventional leaching solvent. This method not only emphasizes environmental sustainability but also establishes itself as an eco-friendly leaching technology for platinum group metal extraction from urban mining waste.In Chapter 5, strategically fabricated PEC capsules with Au(III) selectivity are introduced. These capsules, formed via salt-induced coacervation, exhibit selectivity in multimetal mixtures and provide binding sites through electrostatic attraction. The phenomenon of competing ion rejection is elucidated, and the loaded Au(III) is successfully eluted and regenerated for at least five cycles, rendering it a practically feasible solution for resource recovery through urban mining.In Chapter 6, the design and execution of a novel amino- and sulfur-containing polyhedral oligomeric silsesquioxane (POSS–S-DETA) for highly efficient and selective extraction of precious PGEs are detailed. The material showcases high adsorption efficacies, selectivity, acid resistance, and repeatability for Pd(II) and Pt(IV) over eight consecutive cycles.In Chapter 7, a highly loaded carboxylic acid-functionalized sulfur-containing POSS (POSS–S–COOH) is presented through a one-step method. POSS–S–COOH demonstrates exceptional adsorption capabilities and selectivity for PtCl62− and PdCl42−. Proficient recovery capabilities at pH 10, without harsh desorbents, mark a significant achievement. The pseudo-second-order, intraparticle diffusion kinetic, and Langmuir isotherm data fitting indicate strong interactions between POSS–S–COOH and PtCl62−/PdCl42−.In Chapter 8, a novel branched polyethylenimine (PEI) functionalized sulfur-containing polyhedral oligomeric silsesquioxane (POSS)-based dendritic adsorbent (POSS-S-PEI) are synthesized for the highly proficient and selective capturing of precious metal ions. The developed POSS-S-PEI exhibits highly proficient uptakes and selectivity for Pd(II) and Pt(IV) in the presence of common metal ions. The adsorption studies align with the Langmuir isotherm and pseudo-second-order kinetics, highlighting electrostatic interaction, H-bonding, and chelation as crucial factors.By prioritizing selectivity, efficiency, and environmental sustainability, this thesis significantly advances precious metal recovery from urban mining waste.