Primary silver extraction with a high sulphur activated petroleum coke

• Published in: Water Science & Technology Vol. 49; no. 1; pp. 155 - 162
• Main Authors: Schouwenaars, R, Durán Moreno, A, Ramírez Zamora, R M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: England IWA Publishing 2004
• Subjects: Activated carbon; Adsorption; Coke; Conservation of Natural Resources; Electrochemistry; Extraction; Feasibility studies; Functional groups; Petroleum; Petroleum coke; Refineries; Refuse Disposal; Silver; Silver - isolation & purification; Spectrophotometry, Infrared; Sulfur; Surface chemistry; Titration; Waste materials
• ISBN: 9781843394532; 1843394537
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2004.0045

An extended study was performed to determine the mechanisms that are responsible for the significant silver extraction capacity of activated carbons prepared from a high-sulphur petroleum coke that is available as a waste material from Mexican petroleum refineries. Earlier studies had shown the feasibility of the production of these adsorbents but indicated that the mechanisms of metal adsorption in the present carbons are significantly different from what is classically accepted for commercial carbons. Therefore, selective titration, IR-spectroscopy and scanning electron microscopy of carbons were combined with adsorption experiments and the determination of electrochemical parameters of mixtures of carbon-AgNO3 solution to explain the fundamental reasons for the performance of the obtained carbons. This allowed us to determine the identity of the surface functional groups and to distinguish the effect of different activation processes. The experiments permitted us to explain why these activated carbons, which have a low specific area and lack classical surface functional groups, show such a high silver adsorption capacity.