Ionometallurgy is a new trend to utilise ionic liquids as alternative green solvents for oxidic and sulfidic copper minerals. It has broad potential for traditional pyrometallurgy and hydrometallurgy. Ionometallurgy utilises ionic liquids (ILs), highly potent complexing ligands (chloride), to process oxide and copper sulfide minerals. This work focused on using the deep eutectic solvents (DES) of ionic liquids, which and provide alternative options for processing various metals, alloys, and concentrates.
For this job, various analytical methods were used to determine the copper concentrate and its residue after leaching (MLA-SEM and XRPD), quantify the elements in the solution (IC and ICP-OES/MS) and explain the oxidation behaviour (CV and UV-Vis spectroscopy). Combining the analytical and electrochemical methods to the leaching experiment provided the control to improve the results and understand its oxidation behaviour.
Chosen DES, Oxaline (ChCl + oxalic acid, 1:1), and Ethaline (ChCl + ethylene glycol, 1:2) were tested and enhanced on the actual copper concentrates with and without oxidative additives (FeCl3 and I2). Those oxidative additives are selected for leaching experiments by their redox potential in Ethaline.
However, there are many acceptable values; the most exciting result related to Ethaline plus iodine was the potential leaching system for chalcopyrite and copper-gold concentrates leaching. Because ion chromatography (IC) and UV-Vis’s analysis confirm iodine oxidizes the Cu+ species quickly in Ethaline. Whilst identical results and oxidation behaviour appeared in chalcocite (Cu2S), chalcopyrite (CuFeS2) and copper-gold concentrates leaching.
During the iodine reduction to iodide in the system, IC proved that chalcopyrite releases the Fe3+, oxidizing the chalcopyrite particles. Also, iodine oxidized the natural gold in copper-gold concentrate successfully, and gold concentration quantified ICP-MS and MLA-SEM proved there is no visible gold in the leaching residue.
Based on the optimal Ethaline + I2 leaching condition, the copper concentrate was carried out with the bottle roller leaching to represent the tank leaching. Thus, DES shows that it has a high potential to be continued to scale up the experiment. Also, water was given to the Ethaline leaching system, and water had a good influence on the leaching due to reducing the viscosity and saving the Ethaline amount. Hence Ethaline plus water is used for the copper ore leaching in the column, and it can be seen that Ethaline + I2 with water (up to 20%) has a high potential to process the low-grade copper sulfide ores.:Acknowledgements
Abstract
Abbreviations
TABLE OF CONTENTS
CHAPTER ONE – INTRODUCTION OF COPPER PROCESSING TECHNOLOGIES
1.1. Overview
1.2. Copper
1.3. Gold
1.4. Hydrometallurgy and pyrometallurgy of copper and gold
1.5. Current copper and gold concentrate processing methods
1.6. An alternative copper concentrate processing method
Summary of chapter 1
CHAPTER TWO – FUNDAMENTALS FOR PROCESS DEVELOPING
2.1. Introduction
2.2. Effect of temperature and stirring in leaching
2.3. Analytical methods and experimental
2.4. Experimental for leaching
2.5. Discussion of experimental errors
CHAPTER THREE: ANALYTICAL EXPERIMENTS FOR LEACHING
3.1. Introduction
3.2. Analysis of copper concentrate
3.3. Cyclic voltammetry
3.4. UV-Vis spectroscopy analysis of target metals
3.5. Metals solubility in DES
3.6. Summary and conclusions
CHAPTER FOUR: FUNDAMENTAL LEACHING EXPERIMENT AND INITIAL INVESTIGATION
4.1. Introduction
4.2. Initial study and fundamental leaching experiments
4.3. Study of mineral oxidation
4.4. Deep eutectic solvents leaching
4.5. Chapter summary and conclusion
CHAPTER FIVE: LEACHING OF MODEL SYSTEMS IN ETHALINE WITH OXIDATIVE ADDITIVES
5.1. Introduction
5.2. Iodine effect on Cu2S and CuS leaching in Ethaline
5.3. Ferric chloride effect on CuS and Cu2S leaching
5.4. Leaching of natural gold in Ethaline with the presence of iodine
5.5. Cyclic voltammetry investigation of Cu+/2+ sulfides in DES
5.6. Chapter summary and conclusion
CHAPTER SIX: LEACHING OF COPPER-GOLD CONCENTRATES IN DES AND WITH OXIDATIVE ADDITIVES
6.1. Introduction
6.2. Effect of ferric chloride (FeCl3)
6.3. Effect of iodine (I2)
6.4. Electrochemical and spectroscopic analysis of copper-gold concentrate leachates
6.6. Chapter summary and conclusion
CHAPTER SEVEN: OVERALL CONCLUSION AND FUTURE WORK
7.1. Overall conclusions
7.2. Recommendations for future research
CHAPTER EIGHT: APPENDIX
8.1. Chemicals and materials
8.2. Appendix
References
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:81904 |
| Date | 22 July 2024 |
| Creators | Togtokhbaatar, Purev-Ochir |
| Contributors | Frisch, Gero, Bertau, Martin, Technische Universität Bergakademie Freiberg |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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