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Chapter 16 Rare-earth elements in phosphogypsum and mineral processing residues from phosphate-rich weathered alkaline ultramafic rocks, Brazil

  • Tim Rödel , Stefan Kiefer and Gregor Borg
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Industrial Waste
This chapter is in the book Industrial Waste

Abstract

Abstracts: Phosphogypsum is regarded today mainly as a by-product or waste generated during industrial processes such as the production of phosphoric acid for fertilizer. During the process of sulphuric acid leaching of apatite-rich concentrates from weathered alkaline ultramafic rocks large volumes of gypsum and accessory minerals are produced. Recently nine phosphogypsum samples from Catalão, Brazil have been investigated as a potential secondary source for rare-earth elements (REEs). Identifying the minerals hosting REE, the mineral composition and modal abundance are key in evaluating the economic potential of phosphogypsum as a source for critical metals. A combination of detailed petrographic investigations, SEM-based mineral distribution analyses, EPMA and geochemical analyses using ICP-MS/AES was successfully applied to identify REE carrier minerals and the fraction of associated REE. The analysed phosphogypsum samples are mainly composed of euhdral gypsum crystals constituting around 93% of the total mass. Accessory minerals identified include quartz, octahedral REE-bearing, (Ca-Al-) fluorides, monazite, celestine, Fe-oxides, ilmenite, barite, pyrochlore, and baddeleyite. Apart from gypsum most minerals also occur in the weathered phosphate-rich rocks and are therefore carried over throughout the sulphuric acid leaching process of apatite concentrates. Monazite has been identified as the most important carrier for REE in phosphogypsum. The mineral mainly consists of Ce, La, Nd and P. The total rare-earth content in the mineral amounts to a mean 57 %. Furthermore the Th concentration, a major contaminant, are comparably low. The mean abundance of monazite in phosphogypsum amounts to 0.6wt%. Overall monazite hosts 50% to 60% of the total REE in phosphogypsum, while the remaining 50% are locked in gypsum and Ca-Al-fluorides. Therefore only a fraction of the geochemically available total rare-earth oxide content of 0.6%in phosphogypsum is likely to be recoverable. A good complete particle liberation of 60% to 80% and a grain size range of 15mμm to 50μm is promising for a further beneficiation of monazite by means of physical separation prior to winning the REE. Based on the data at hand phosphogypsum from the Catalão region in Brazil could potentially provide a significant supply of REE as a secondary resource.

Abstract

Abstracts: Phosphogypsum is regarded today mainly as a by-product or waste generated during industrial processes such as the production of phosphoric acid for fertilizer. During the process of sulphuric acid leaching of apatite-rich concentrates from weathered alkaline ultramafic rocks large volumes of gypsum and accessory minerals are produced. Recently nine phosphogypsum samples from Catalão, Brazil have been investigated as a potential secondary source for rare-earth elements (REEs). Identifying the minerals hosting REE, the mineral composition and modal abundance are key in evaluating the economic potential of phosphogypsum as a source for critical metals. A combination of detailed petrographic investigations, SEM-based mineral distribution analyses, EPMA and geochemical analyses using ICP-MS/AES was successfully applied to identify REE carrier minerals and the fraction of associated REE. The analysed phosphogypsum samples are mainly composed of euhdral gypsum crystals constituting around 93% of the total mass. Accessory minerals identified include quartz, octahedral REE-bearing, (Ca-Al-) fluorides, monazite, celestine, Fe-oxides, ilmenite, barite, pyrochlore, and baddeleyite. Apart from gypsum most minerals also occur in the weathered phosphate-rich rocks and are therefore carried over throughout the sulphuric acid leaching process of apatite concentrates. Monazite has been identified as the most important carrier for REE in phosphogypsum. The mineral mainly consists of Ce, La, Nd and P. The total rare-earth content in the mineral amounts to a mean 57 %. Furthermore the Th concentration, a major contaminant, are comparably low. The mean abundance of monazite in phosphogypsum amounts to 0.6wt%. Overall monazite hosts 50% to 60% of the total REE in phosphogypsum, while the remaining 50% are locked in gypsum and Ca-Al-fluorides. Therefore only a fraction of the geochemically available total rare-earth oxide content of 0.6%in phosphogypsum is likely to be recoverable. A good complete particle liberation of 60% to 80% and a grain size range of 15mμm to 50μm is promising for a further beneficiation of monazite by means of physical separation prior to winning the REE. Based on the data at hand phosphogypsum from the Catalão region in Brazil could potentially provide a significant supply of REE as a secondary resource.

Chapters in this book

  1. Frontmatter I
  2. Contents V
  3. List of Authors IX
  4. Part 1: Measurement and properties
  5. Chapter 1 Characterization of supplementary cementitious materials and their quantification in cement blends by solid-state NMR 3
  6. Chapter 2 Mineralogical quantification of cements, wastes and supplementary cementitious materials 33
  7. Chapter 3 Microstructure analysis with quantitative phase mapping using SEM-EDS and Phase Recognition and Characterization (PARC) Software: applied to steelmaking slag 57
  8. Chapter 4 The use of μXRF in the characterization of industrial wastes and pozzolanes 97
  9. Part 2: Characterization of industrial residues
  10. Chapter 5 Characterization of supplementary cementitious materials: Brown coal fly ashes 165
  11. Chapter 6 Iron and steel slags: from wastes to by-products of high technical, economical and ecological advantages 203
  12. Chapter 7 Utilization of Supplementary cementitious materials (SCM) in Portland cement, alkali activated and ternary binders 253
  13. Chapter 8 Study of some physico chemical properties of plastic clays belonging to Girujan deposits from Chumoukedima Nagaland, India and their prospective industrial applications 297
  14. Part 3: Use and application of industrial residues
  15. Chapter 9 Conversion of CO2 into useful products 319
  16. Chapter 10 Mine tailings as precursors for alkali-activated materials and ettringite binders 345
  17. Chapter 11 Industrial waste as fuel and raw material in the cement industry 361
  18. Chapter 12 Fly ash from municipal solid waste Incineration: from industrial residue to resource for zinc 379
  19. Chapter 13 Residues of industrial wastewater treatment: Hazardous waste or anthropogenic resource? 403
  20. Chapter 14 Composites of some sustainable siliceous materials for the removal of fluoride from ground water and immobilization of the sludge generated 433
  21. Part 4: Residues from mining
  22. Chapter 15 Characterization and mineral processing options of “Kupferschiefer”-type low-grade black shale ore from mining dumps in Central Germany 455
  23. Chapter 16 Rare-earth elements in phosphogypsum and mineral processing residues from phosphate-rich weathered alkaline ultramafic rocks, Brazil 505
  24. Chapter 17 The Mn oxides tailing from Amazon Region as low-cost raw material to synthesis of shigaite-type phase 541
  25. Chapter 18 Eco-cements out of Belterra Clay: An extensive Brazilian bauxite overburden to produce low-CO2 eco-friendly calcium sulphoaluminate based cements 553
  26. Index 581
https://doi.org/10.1515/9783110674941-016

Chapters in this book

  1. Frontmatter I
  2. Contents V
  3. List of Authors IX
  4. Part 1: Measurement and properties
  5. Chapter 1 Characterization of supplementary cementitious materials and their quantification in cement blends by solid-state NMR 3
  6. Chapter 2 Mineralogical quantification of cements, wastes and supplementary cementitious materials 33
  7. Chapter 3 Microstructure analysis with quantitative phase mapping using SEM-EDS and Phase Recognition and Characterization (PARC) Software: applied to steelmaking slag 57
  8. Chapter 4 The use of μXRF in the characterization of industrial wastes and pozzolanes 97
  9. Part 2: Characterization of industrial residues
  10. Chapter 5 Characterization of supplementary cementitious materials: Brown coal fly ashes 165
  11. Chapter 6 Iron and steel slags: from wastes to by-products of high technical, economical and ecological advantages 203
  12. Chapter 7 Utilization of Supplementary cementitious materials (SCM) in Portland cement, alkali activated and ternary binders 253
  13. Chapter 8 Study of some physico chemical properties of plastic clays belonging to Girujan deposits from Chumoukedima Nagaland, India and their prospective industrial applications 297
  14. Part 3: Use and application of industrial residues
  15. Chapter 9 Conversion of CO2 into useful products 319
  16. Chapter 10 Mine tailings as precursors for alkali-activated materials and ettringite binders 345
  17. Chapter 11 Industrial waste as fuel and raw material in the cement industry 361
  18. Chapter 12 Fly ash from municipal solid waste Incineration: from industrial residue to resource for zinc 379
  19. Chapter 13 Residues of industrial wastewater treatment: Hazardous waste or anthropogenic resource? 403
  20. Chapter 14 Composites of some sustainable siliceous materials for the removal of fluoride from ground water and immobilization of the sludge generated 433
  21. Part 4: Residues from mining
  22. Chapter 15 Characterization and mineral processing options of “Kupferschiefer”-type low-grade black shale ore from mining dumps in Central Germany 455
  23. Chapter 16 Rare-earth elements in phosphogypsum and mineral processing residues from phosphate-rich weathered alkaline ultramafic rocks, Brazil 505
  24. Chapter 17 The Mn oxides tailing from Amazon Region as low-cost raw material to synthesis of shigaite-type phase 541
  25. Chapter 18 Eco-cements out of Belterra Clay: An extensive Brazilian bauxite overburden to produce low-CO2 eco-friendly calcium sulphoaluminate based cements 553
  26. Index 581
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