QUANTIFYING THE MINERAL CARBONATION POTENTIAL OF MINE WASTE MATERIAL: A NEW PARAMETER FOR GEOSPATIAL ESTIMATION by ANTHONY DAVID JACOBS M.Sci (Honours), The University of Birmingham, 2007 M.Sc., The University of Exeter (Camborne School of Mines), 2008 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate and Postdoctoral Studies (Mining Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) October 2014 © Anthony David Jacobs, 2014 Abstract Direct aqueous mineral carbonation is a CO2 sequestration method that can trap anthropogenic carbon dioxide as a thermodynamically stable carbonate. Ultramafic rocks considered waste at mining operations are targeted as the substrate source for carbonation in this research. Using mining waste to permanently fix CO2 is a motivating factor for promoting industrial mineral carbonation as a viable carbon sequestration option. Experimental direct aqueous mineral carbonation was carried out on proposed Turnagain waste rock, a low-grade, high tonnage nickel sulphide deposit in northern British Columbia. 45 % magnesium silicate to magnesium carbonate conversion was achieved in two hours. The successful sequestration of CO2 using mining waste rock and the opportunity of shared mining and mineral processing costs of a dual mining/mineral carbonation operation can aid in reducing economic and energy requirements, identified as key inhibiting factors of industrial mineral carbonation. The heterogenous mineralogy of ultramafic deposits commonly hosting mining operations makes quantifying the mineral carbonation potential (MCP) of the waste rock challenging. The MCP calculator, a novel Microsoft ExcelTM spreadsheet program was developed to estimate the modal mineral abundance of ultramafic rocks for use in MCP estimation. The calculator is intended for use by the mining industry utilising abundant lithogeochemical data as a cost-effective tool in evaluating their deposit as a supplier of substrate material for industrial mineral carbonation operation. The calculator can be tailored to estimate MCP values based on a site specific mineral assemblage. MCP values generated represent composited sample length intervals along exploration drill holes. Estimation techniques traditionally used by the mining industry for resource estimation were evaluated as methods of geospatially interpolating MCP values. Both inverse distance and ordinary kriging were successful in interpolating MCP values. A capacity of 75 million tonnes of CO2 within the proposed 28 year surface mine design at Turnagain was calculated. This capacity is significantly lower than the theoretical maximum capacity of 538 million tonnes calculated assuming all MgO within the waste rock is capable of sequestering CO2 as magnesite (MgCO3). The research highlights the importance of understanding and quantifying the mineralogy of ultramafic deposits when estimating their potential for mineral carbonation. ii Preface The dissertation is original, unpublished, independent work by the author, Anthony Jacobs. Some external laboratory testing and analysis was undertaken and the results are reproduced herein by the author; X-ray diffraction with Rietveld refinement analysis was undertaken by the Electron Microbeam/X-ray Diffraction Facility, Earth and Ocean Science Department, The University of British Columbia. ICP-ES lithogeochemial and X-ray fluoresence major oxide analyses was undertaken by the Acme Analytical Laboratories, Vancouver, British Columbia. iii Table of contents Abstract .................................................................................................................................................. ii Preface ................................................................................................................................................... iii Table of contents ................................................................................................................................... iv List of tables ........................................................................................................................................... ix List of figures ......................................................................................................................................... xi List of symbols and abbreviations ........................................................................................................ xiv Acknowledgements .............................................................................................................................. xvi Dedication ........................................................................................................................................... xvii 1 Introduction .................................................................................................................................. 1 1.1 Climate change and the carbon cycle ....................................................................................... 1 1.2 Carbon capture and storage technologies ................................................................................ 3 1.2.1 CO2 capture ....................................................................................................................... 4 1.2.2 CO2 transport .................................................................................................................... 4 1.2.3 Geological storage ............................................................................................................. 5 1.2.4 Mineral storage ................................................................................................................. 6 1.3 Carbon capture and storage in the mining industry ................................................................. 7 1.4 Dissertation structure ............................................................................................................. 10 1.4.1 Dissertation focus ........................................................................................................... 10 1.4.2 Dissertation questions .................................................................................................... 11 1.4.3 Chapter organisation ...................................................................................................... 12 2 Literature review: ex-situ mineral carbonation and modal mineral estimation ........................ 15 2.1 Mineral carbonation background ........................................................................................... 15 2.2 Mineral carbonation process pathways .................................................................................. 16 2.2.1 Direct mineral carbonation ............................................................................................. 17 2.2.2 Indirect mineral carbonation .......................................................................................... 19 2.3 Geology and sources of substrate material ............................................................................ 21 iv 2.3.1 Mafic and ultramafic rocks ............................................................................................. 21 2.3.2 Mining waste rock and solid industrial waste streams ................................................... 25 2.4 Experimental direct aqueous mineral carbonation ................................................................ 26 2.4.1 Mineral pre-treatment .................................................................................................... 28 2.4.2 Aqueous solution chemistry and experimental carbonation conditions ........................ 29 2.5 Estimating the mineral carbonation capacity of ultramafic rocks .......................................... 32 2.5.1 Mineral carbonation controlling factors on resource estimation................................... 34 2.5.2 Estimating mineralogy from lithogeochemical data ....................................................... 41 2.6 Resource estimation in the mining industry ........................................................................... 44 2.6.1 Traditional empirical approaches to resource estimation .............................................. 46 2.6.2 Geostatistical approaches to resource estimation ......................................................... 47 3 Experimental, analytical and modelling procedures .................................................................. 50 3.1 Deposit selection and background .......................................................................................... 50 3.1.1 Twin Sisters ultramafic complex ..................................................................................... 50 3.2.2 Turnagain ultramafic complex ........................................................................................ 52 3.2 Sample collection .................................................................................................................... 56 3.3 Sample preparation ................................................................................................................ 57 3.3.1 Density measurements ................................................................................................... 57 3.3.2 Rock crushing and grinding ............................................................................................. 58 3.4 Analytical methods ................................................................................................................