Louisiana State University LSU Digital Commons LSU Master's Theses Graduate School 2003 The determination of appropriate phosphogypsum: Class C fly ash : Portland Type II cement compositions for use in marine applications Pradyot Sudhakar Deshpande Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_theses Part of the Civil and Environmental Engineering Commons Recommended Citation Deshpande, Pradyot Sudhakar, "The determination of appropriate phosphogypsum: Class C fly ash : orP tland Type II cement compositions for use in marine applications" (2003). LSU Master's Theses. 1697. https://digitalcommons.lsu.edu/gradschool_theses/1697 This Thesis is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Master's Theses by an authorized graduate school editor of LSU Digital Commons. For more information, please contact [email protected]. THE DETERMINATION OF APPROPRIATE PHOSPHOGYPSUM:CLASS C FLY ASH:PORTLAND TYPE II CEMENT COMPOSITIONS FOR USE IN MARINE APPLICATIONS A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering in The Department of Civil and Environmental Engineering by Pradyot S. Deshpande B.E., Swami Ramanand Teerth Marathwada University, India, 2000 August 2003 This Thesis Work Is Dedicated To My Loving Parents: Prin. Sudhakar V. Deshpande and Mrs. Shobhana S. Deshpande ii Acknowledgements I would like to thank all those individuals who helped me throughout the tenure of my graduate studies at LSU. Firstly, thanks a lot to my major advisor Dr. Kelly A. Rusch for her constant support and encouragement. I feel myself lucky to have such a wonderful learning experience under her guidance. It’s always been an inspiration to see her passion for the research work. I would also like to extend the note of thanks to my committee members Dr. Roger K. Seals and Dr. Frank K. Cartledge for the valuable guidance and recommendations they provided for this research that helped me craft my thesis document successfully. Thanks also to the Florida Institute of Phosphate Research for funding this research. I wish to thank Dr. Tingzong Guo for all the help and expert opinions he gave me to get better outcome from my study. I also thank Mrs. Sarah Jones for all her patience and help in analyzing the samples and her suggestions that really helped me properly understand the results. Thanks to the fertilizer industry for producing Phosphogypsum! I further want to thank Dr. Ronald Malone and Mrs. Sandy Malone for the occasional kind advices and funny talks. Thanks a lot to Mr. William van Beuningen and Mrs. Susan van Beuningen for the hospitality and affection. Friendship with them is like a very special surprise gift to me that I would cherish forever. Special thanks to all my friends especially, Tej, Jennifer, Jeremy, Steve, Teresa, Will, Amy, and Cynthia for all those ‘studious’ discussions, helping hands, crazy moments and ever-growing laughs we shared while at work. Studying at the graduate school would never be the same without them all. Thanks to my roommates Amogh and iii Amol for encouraging me through the most frustrating circumstances and for such a wonderful company that would always make me feel like home. Thanks to Trupti for always being with me. Finally, I would like to express my deepest regards to my parents, sisters and family without whom I would have never accomplished all this. Thank you very much for believing in me. iv Table of Contents Dedication Page .................................................................................................................. ii Acknowledgements............................................................................................................iii List of Tables ...................................................................................................................viii List of Figures.................................................................................................................... xi Abstract .......................................................................................................................xiii Chapter 1: Global Introduction ........................................................................................... 1 1.1 Phosphoric Acid Production and Phosphogypsum Generation ............................... 2 1.2 Potential Phosphogypsum Applications .................................................................. 7 1.3 Phosphogypsum Stabilization for Use in Coastal Applications ............................ 10 1.3.1 Need for Coastal Material.......................................................................... 10 1.3.2 Stabilization of Phosphogypsum................................................................ 11 1.3.3 Leaching Mechanisms ............................................................................... 13 1.3.4 Geotechnical Properties ............................................................................. 15 1.4 Research Objectives............................................................................................... 19 Chapter 2: Selection of the Stabilized Phosphogypsum:Class C Fly Ash:Portland Type II Cement Composite Combinations for Use in Marine Environments .................................................................................................. 21 2.1 Introduction............................................................................................................ 21 2.2 Materials and Methodology ................................................................................... 23 2.2.1 Selection of PG Composite Combinations ................................................... 24 2.2.2 Evaluation Criteria........................................................................................ 27 2.2.3 Experimental Testing.................................................................................... 28 2.2.3.1 Field Submergence........................................................................ 28 2.2.3.2 Dynamic Leaching Test ................................................................ 29 2.2.3.3 Diffusion Model............................................................................ 31 2.2.3.4 Cost of the Composites ................................................................ 36 2.2.3.5 Toxicity Characteristic Leaching Procedure (TCLP) ................... 36 2.3 Results and Discussions ........................................................................................37 2.3.1 Phase I: Screening of the Nine PG Composite Combinations...................... 37 2.3.1.1 Field Submergence........................................................................ 37 2.3.1.2 Effective Calcium Diffusion Coefficients .................................... 41 2.3.1.3 Effective Sulfate Diffusion Coefficients....................................... 43 2.3.1.4 Economic Analysis ....................................................................... 45 2.3.2 The Selection of the Best Four Combinations .............................................. 47 2.3.3 Phase II: Evaluation of the Selected Final Four Combinations .................... 49 2.3.3.1 Effective Calcium and Sulfate Diffusion Coefficients ................. 50 2.3.3.2 Investigation of the Potential for the Formation of Magnesium Compounds................................................................................... 52 v 2.3.3.3 Diffusion of Heavy Metals............................................................ 54 2.3.3.4 Radium226 Measurements.............................................................. 57 2.3.3.5 TCLP Results................................................................................ 59 2.4 Conclusions............................................................................................................ 60 Chapter 3: Investigation of the Engineering Properties of the Stabilized Phosphogypsum:Class C Fly Ash:Portland Type II Cement Composites for Potential Use in Marine Environments ..................................................... 62 3.1 Introduction............................................................................................................ 62 3.2 Materials and Methodology ................................................................................... 66 3.2.1 Raw Material Characterization ..................................................................... 67 3.2.1.1 Physical and Chemical Properties of Phosphogypsum................. 67 3.2.1.2 Physical and Chemical Composition of Class C Fly Ash............. 68 3.2.1.3 Chemical Composition of Portland Type II Cement ................... 69 3.2.2 Fabrication of PG Composite Briquettes ...................................................... 70 3.2.3 Field Submergence Study ............................................................................. 71 3.2.4 Specific Gravity and Standard Proctor Compaction Tests ........................... 72 3.2.5 Particle Size Distribution (Sieve Analysis)................................................... 73 3.2.6 Surface Hardness.......................................................................................... 74 3.2.7 Dry/Wet Weight Study ................................................................................75