Kinetic and Thermodynamic Studies of Precious Metals Sorption on Impregnated Lewatit VP OC 1026 from Chloride Solutions

Abstract

Precious metals are used in many branches of industries. Due to their rarity and diminishing natural resources, more and more new methods are being sought to recover them from secondary sources, which can be electronic waste or spent car exhaust converters. This paper presents the research on the recovery of precious metals from chloride solutions using the Aliquat 336‐impregnated Lewatit VPOC 1026 sorbent. The study used a warm impregnation method without toxic solvents, which is beneficial for the environment. The maximal sorption capacities obtained for model solutions in 0.1 M HCl were: 95.6 mg/g for gold, 38.2 mg/g for palladium, and 36.2 mg/g for platinum. There were studied: kinetics and thermodynamics of adsorption, as well as amounts of the adsorbent, effects of phase contact time and HCl concentration on the adsorption of precious metals. Positive values of enthalpy change ΔH° validate that the process is endothermic. The research was also carried out on a real leaching solution obtained by digesting a spent catalytic converter, containing small amounts of platinum group metals. Desorption of precious metal ions was conducted using 1M thiourea in 1M hydrochloric acid. The obtained impregnated sorbent proved to be effective for adsorption of Au(III), Pd(II), Pt(IV) ions.

Impregnated Polymeric Sorbent for the Removal of Noble Metal Ions from Model Chloride Solutions and the RAM Module

“…In our previous studies, SIRs for the sorption of noble metals, including gold, palladium and platinum, were applied giving positive results. Properties of commercially available adsorbents were altered by their impregnating with the extractant selective for noble metal ions [ 22 , 23 ]. The paper aimed at the sorption of Au(III), Pd(II), Pt(IV) and Rh(III) ions from chloride model solutions and the verification of suitability of the impregnated resin for the recovery of noble metals from the real system, i.e., digested random access memory module.…”