AN EXERGETIC COMPARISON OF COPPER EXTRACTION FROM CHALCOPYRITE CONCENTRATES BY PYROMETALLURGY AND HYDROMETALLURGY by Paul Mather A Dissertation Submitted to the Faculty of Purdue University In Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy School of Materials Engineering West Lafayette, Indiana December 2020 THE PURDUE UNIVERSITY GRADUATE SCHOOL STATEMENT OF COMMITTEE APPROVAL Dr. Matthew J. M. Krane, Chair School of Materials Engineering Dr. Kenneth H. Sandhage School of Aeronautics and Astronautics Dr. Kevin P. Trumble School of Materials Engineering Dr. Neera Jain School of Mechanical Engineering Approved by: Dr. David F. Bahr 2 Dedicated to my beautiful wife Madelyn 3 ACKNOWLEDGEMENTS I owe more than I can say to my wife, parents, and friends. A large deal of gratitude is owed to the Freeport-McMoRan Inc. (our funding source) and the FMI Tucson Technology Center staff, namely Dr. Jodie Robertson and Tom Bolles, as well as the FMI Miami Smelter staff, namely David Jones, Brandon Steinborn, Avi Nanda, and Alex Piatkiewicz, for making this work possible. Finally, I can’t say enough in gratitude to the Order of Preachers, namely the St. Tom’s staff and Fr. Donald Bramble of the Western Province. Laudare, benedicere, praedicare! 4 TABLE OF CONTENTS LIST OF TABLES................................................................................................................................ 9 LIST OF FIGURES ............................................................................................................................ 11 ABSTRACT ........................................................................................................................................ 17 1. INTRODUCTION ...................................................................................................................... 18 1.1 Overview of Copper Extraction................................................................................................ 18 1.2 Exergy — What It is and Why It is Useful ............................................................................. 20 1.3 Bath Smelting ........................................................................................................................... 22 1.4 Peirce-Smith Converting of Copper Matte ............................................................................. 24 1.5 Fire Refining .............................................................................................................................. 27 1.6 Autoclave Leaching ................................................................................................................. 30 2. BATH SMELTING MODEL ..................................................................................................... 33 2.1 Model Description ................................................................................................................... 33 2.1.1 Domain and Chemistry .................................................................................................... 33 2.1.2 Thermochemical Mass Balance on the Melt and Gas Volume ..................................... 35 2.1.3 Energy Balance ................................................................................................................. 37 2.1.4 Exergy Balance .................................................................................................................. 38 2.1.5 Property Data ................................................................................................................... 40 2.1.6 Solution Method .............................................................................................................. 41 2.2 Results and Discussion.............................................................................................................. 42 2.2.1 The Baseline Case ............................................................................................................. 42 2.2.2 Oxygen Injection Rate Variation ..................................................................................... 47 2.2.3 Oxygen Grade Variation .................................................................................................. 51 2.2.4 Pyrite Grade of Concentrate Variation ............................................................................ 55 2.2.5 Silica Grade of Concentrate Variation ............................................................................ 58 2.3 Conclusions and Recommendations ....................................................................................... 59 3. PEIRCE-SMITH CONVERTING ............................................................................................. 60 3.1 Model Description .................................................................................................................... 60 3.1.1 Slag Blow Regime ............................................................................................................ 60 3.1.2 Thermochemical Mass Balance for the Slag Blow during Air Injection ...................... 61 5 3.1.3 Energy Balance for the Slag Blow................................................................................... 65 3.1.4 Copper Blow Regime ....................................................................................................... 66 3.1.5 Mass Balance for the Copper Blow ................................................................................. 68 3.1.6 Heat Balance for the Copper Blow .................................................................................. 68 3.1.7 Property Data .................................................................................................................... 68 3.1.8 Exergy Balance for the Slag and Copper Blows .............................................................. 69 3.1.9 Solution Method................................................................................................................ 70 3.2 Results for the Slag-Blow ........................................................................................................ 70 3.2.1 Base Case .......................................................................................................................... 70 3.2.2 Air Injection Rate Variation ............................................................................................. 76 3.2.3 Oxygen Grade Variation .................................................................................................. 78 3.2.4 Silica Addition Variation.................................................................................................. 79 3.2.5 Starting Matte Composition Variation ............................................................................ 80 3.2.6 Oxygen Efficiency Variation ........................................................................................... 82 3.2.7 Heat Loss Variation .......................................................................................................... 83 3.3 Results for the Copper-Blow ................................................................................................... 84 3.3.1 The Baseline Case ............................................................................................................. 84 3.3.2 Oxygen Grade Variation Cases ........................................................................................ 88 3.3.3 Air Injection Rate Variation Cases .................................................................................. 89 3.3.4 Effect of Changes to Oxygen Efficiency ......................................................................... 90 3.3.5 Heat Loss Variation Cases ............................................................................................... 91 3.4 Conclusions and Recommendations ....................................................................................... 92 4. COPPER FIRE REFINING ........................................................................................................ 94 4.1 Desulfurization of Blister Copper ............................................................................................ 94 4.1.1 Model Description ............................................................................................................ 94 4.1.2 Results and Discussion .................................................................................................... 105 4.1.3 Conclusions and Recommendations .............................................................................. 119 4.2 Reduction of Desulfurized Blister Copper ........................................................................... 120 4.2.1 Model Description .......................................................................................................... 120 4.2.2 RESULTS AND DISCUSSION .................................................................................... 130 4.2.3 Conclusions and Recommendations .............................................................................. 149 6 5. THE CONCENTRATE LEACH PROCESS .......................................................................... 151 5.1 Model Description .................................................................................................................. 151 5.1.1 Slurry Model ................................................................................................................... 151 5.1.2 Gas Phase Model