The Robert M. Buchan Department of Mining at Queen's University
Current Projects
Electrochemical investigation of gold cyanidation process: This project focuses on developing the fundamental knowledge of gold cyanidation chemistry, and the effect of some selected minerals such as galena, pyrite etc. on gold cyanidation kinetics.
Alternative lixiviants for gold processing: The message for the gold mining industry is clear: cyanide application for gold processing will be more and more challenging due to its toxicity, cyanide permitting issues, and environmental challenges. Thus we see the value on understanding the chemistry of gold extraction with alternative gold processing lixiviants. The list of the lixiviants includes but not limited to: thiosulfate, halides, thiourea, thiocyanate, glycine, sulfides and sulfites systems and some other less known lixiviants.
Atmospheric Leaching of Complex Arsenic-Containing Copper Sulfide Concentrates: The focus of this research project is to investigate the fundamentals of chalcopyrite and enargite leaching/oxidation under atmospheric conditions in acidic ferric chloride/sulfate solutions and to develop a novel atmospheric leaching process for the treatment of the arsenic-containing copper sulfide concentrates.
Atmospheric Oxidation of Pyritic Gold Ores: The purpose of this project is to study the atmospheric oxidation of pyrite (FeS2) and to develop a sustainable and environmentally responsible pyrite oxidation process with fast kinetics and high elemental sulfur yield.
Electrochemical Oxidation of Pyrite: We apply advanced electrochemical techniques to study the oxidation mechanism of pyrite and develop a good grasp of its fundamentals and identify the driving forces for sulfide oxidation to both sulfate and elemental sulfur. The findings of this study are expected to shed light on the development of the pyrite oxidation process with high elemental sulfur yield via impeding the sulfate producing reactions.
Process Selection for Refractory Gold Ores and Concentrates: We seek two goals with this project: (1) to develop a practical methodology to categorize different refractory gold ores based on their mineralogy, and (2) to develop an effective and easy-to-follow procedure to determine the optimum method for gold recovery from a given gold ore and concentrate.
Arsenic Oxidation and Immobilization From Metallurgical Process Solutions: Arsenic is a highly toxic compound that is naturally found in the environment and is released through the processing of sulfide minerals. Arsenate (As5+) can form insoluble precipitates when metal ions such as ferric are present. Hydrogen peroxide can be employed to oxidize arsenite (As3+) to arsenate (As5+); however, it is expensive. In a recent patent Prof. Ahmad G. and his colleagues at Barrick Gold Corp. have shown that activated carbon can be used to catalyze the oxidation of arsenite with oxygen as the only consumed reagent at ambient conditions with an efficiency of 99% in less than 24 hours. This study focuses on the fundamentals and mechanism of this oxidation process through advanced chemical, electrochemical and analytical techniques.
HCl recovery from MgCl2 solutions: The objective of this project is to develop a sustainable process that can immobilize magnesium and recover the chloride ion as hydrochloric acid from MgCl2 solutions.
Leaching and recovery of Rare Earth Elements (REE): We have few active projects on REE. One project focuses on the separation of heavy and light rare elements early in the process stages. In another project we look into the cerium oxidation with a low cost process. We are investigating the REE adsorption by gypsum in another project.
