HYDROMETALLURGICAL BENEFICIATION OF ILMENITE by Amanda Qinisile Vilakazi A dissertation submitted to meet the requirements for the degree of Master of Science In the faculty of Natural and Agricultural Sciences Department of Chemistry University of the Free State Bloemfontein Supervisor: Prof. W. Purcell Co-supervisor: Dr. M. Nete July 2017 DECLARATION BY CANDIDATE I hereby declare that this dissertation submitted for Master’s degree in Chemistry at the University of the Free State is my own original work and has not been previously submitter to another university or faculty. I further declare that all sources cited and quoted are acknowledged by a list of comprehensive references. Signature …………………….. … Date…………………. Amanda Qinisile Vilakazi ACKNOWLEDGEMENT I hereby wish to express my gratitude to a number of people who made this research a success. Prof. W. Purcell (Supervisor): for his guidance, persistence and patience throughout the research project. Your expertise is highly acknowledged. Thank you for giving me the opportunity to further my academic career. Dr M. Nete (Co-supervisor): No words can express my gratitude towards your role in the success of this thesis. Thank you for your countless guidance, support and motivation, not to mention your assistance in reviewing each and every chapter with excellence. The analytical chemistry group (L. Ntoi, S. Xaba, D. Nhlapo, H. Mnculwane, G. Malefo, A. Ngcephe, D. Mona, Dr T. Chiweshe and Dr S. Kumar) and P. Nkoe, thank you for your assistance and for providing a fun and productive environment. I also wish to thank my mother M.M. Vilakazi and my uncle K.P. Vilakazi; you made the last months of my studies a success with your patience and Love. To the family at large, thank you for your support; “Ngiyabonga Binda, Mphephethe” Amanda Qinisile Vilakazi TABLE OF CONTENTS LIST OF FIGURES ................................................................................................. .vii LIST OF TABLES .................................................................................................... .xi LIST OF ABBREVIATIONS ................................................................................... .xvii KEY WORDS ........................................................................................................ .xix CHAPTER 1: Motivation of the study ....................................................................... 1 1.1 Background of the study ..................................................................................... .1 1.2 Motivation of the study ....................................................................................... .4 1.3 Aim of the study................................................................................................... 6 CHAPTER 2: Introduction ......................................................................................... 7 2.1 Introduction ........................................................................................................ .7 2.2 Titanium distribution ........................................................................................... .9 2.3 Production, Market and Beneficiation .............................................................. .14 2.3.1 Production ................................................................................................. .14 2.3.2 Market ........................................................................................................ 22 2.3.3 Beneficiation .............................................................................................. 24 2.3.3.1 Mining of ilmenite ore .......................................................................... 24 2.3.3.2 Processing of the ore .......................................................................... 27 2.4 The mineral Ilmenite .......................................................................................... 31 2.5 Titanium and Iron chemistry .............................................................................. 34 2.5.1 Physical and chemical properties of titanium and iron ............................... 35 2.5.2. Oxide compounds ..................................................................................... 37 2.5.3 Halide compounds ..................................................................................... 38 2.5.3.1 Titanium halides .................................................................................. 38 2.5.3.2 Iron halides ......................................................................................... 39 2.5.4 Coordination chemistry of iron and titanium ............................................... 39 2.5:5 Organometallic complexes ......................................................................... 41 2.6 Applications and uses of Titanium and Iron ....................................................... 42 2.7 Conclusion ........................................................................................................ 44 Table of Contents CHAPTER 3: Dissolution and seperation of titanium and iron: Literature review .............................................................................................................. 45 3.1 Introduction ....................................................................................................... 45 3.2 Dissolution of titanium and iron containing minerals ......................................... 46 3.2.1 Acid//base dissolution technique ................................................................ 46 3.2.2 Flux fusion digestion and dissolution.......................................................... 50 3.2.3 Microwave acid-assisted digestion ............................................................. 51 3.3 Separation of Ti and Fe in ilmenite .................................................................... 52 3.3.1 Precipitation ............................................................................................... 52 3.3.2 Solvent extraction ...................................................................................... 54 3.3.3 Ion exchange ............................................................................................. 56 3.4 Analytical techniques ......................................................................................... 58 3.4.1 Spectroscopic techniques .......................................................................... 59 3.4.1.1 Solution analysis ................................................................................. 59 3.4.1.2 Direct solid analysis ............................................................................ 64 3.5 Characterization techniques .............................................................................. 67 3.6 Conclusion ........................................................................................................ 69 CHAPTER 4: Selection of analytical techniques .................................................. 71 4.1 Introduction ....................................................................................................... 71 4.2 Sample dissolution methods ............................................................................. 72 4.2.1 Conventional acid digestion method .......................................................... 72 4.2.2 Flux fusion method ..................................................................................... 74 4.2.3 Microwave digestion ................................................................................... 76 4.3 Seperation techniques ....................................................................................... 77 4.3.1 Selective precipitation ................................................................................ 77 4.3.2 Solvent extraction ...................................................................................... 80 4.3.3 Ion exchange chromatography .................................................................. 85 4.4 Quantification and charecterization techniques ................................................. 87 4.4.1 Inductively coupled plasma spectroscopy (ICP-OES ................................. 88 4.4.2 Scanning electron microscope with energy dispersive spectroscopy (SEM- EDS) ............................................................................................................... 91 4.4.3 Infrared (IR) Spectroscopy ......................................................................... 95 4.4.4 CHNS micro-analyser ................................................................................ 97 ii Table of Contents 4.5 Conclusion ........................................................................................................ 99 CHAPTER 5: Dissolution and analysis of titanium and iron containing samples ............................................................................................................. 100 5.1 Introduction ..................................................................................................... 100 5.2 Experimental procedures ................................................................................ 101 5.2.1 Reagent and equipment ........................................................................... 101 5.2.2 Sample background ................................................................................. 103 5.2.3 Preparation of calibration standards for ICP-OES analysis ...................... 103 5.2.4 Determination of limit of detection and