Study the effects of calcinations and evolution of crystallographic parameters of two Tunisian natural phosphates

  • Abstract
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  • References
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  • Abstract

    Tunisian natural phosphate is a highly form of fluorapatite, carbonate fluorapatite, also known as francolite. The presence of carbonate in mineral phosphates influences their reactivity overlooked acid attack, but their presence requires a supplementary adding of sulfuric acid in the plants of production of phosphoric acid; and causing the formation of foams in the reactors during the addition of sulfuric acid. The presence of carbonates in high contents reduces the price value of phosphate rock.

    We propose in this work to study thermally the decomposition of two carbonated fluorapatite in a range of temperature between ambient and 1000C; and the variation of the value of crystallographic parameters of the two samples of phosphate. The X-ray diffraction technique is used for this mineralogical study.

    By referring to the crystallographic parameters of the lattice of phosphate, we note that the increase in temperature decarbonated the francolite which is transformed largely to a fluoroapatite. In addition, it was reported that the first decarbonation is around 650C translated the kinetics of decomposition of the carbonate ions of the type B associated with a vaccum, while the second decarbonation is around 1000C and related to the thermal decomposition of the entity of CO3F, generated by the decomposition of carbonate ions of type B and A. The presence of these ions would be the result of a reorganization of the crystal lattice.

    Keywords: Carbonated fluoroapatite, effect of calcinations, mineralogical study, Tunisian natural phosphate, x-ray diffraction.

  • References

    1. Becker P (1989) Phosphates and Phosphoric acid, Marcel Decker.
    2. Bonel G (1972) Annales de Chimie (Paris) 7, 127-144.
    3. CHAABOUNI A, CHTARA C, NZIHOU A & EL FEKI H (2013) Kinetic Study of the Dissolution of Tunisian Natural Phosphate or Francolite in Industrial Phosphoric Acid. Journal of Advances in Chemistry 6, 908-916.
    4. Chien SH & Black CA (1976) Free energy of formation of car-bonate apatites in some phosphate rocks. Soil Science Society of America Journal 40, 234-239.
    5. EL FEKI H, KHATTECH I, JEMAL M & Rey C (1994) Dcomposition thermique d'hydroxyapatites carbonates sodes Thermochimica Acta 237, 99-110.
    6. EL FEKI H, KHATTECH I & JEMAL M (1991) Dcomposition thermique de fluorapatites carbonates sodes. Journal de Chimie Physique 88, 1885-1892.
    7. EL FEKI H, Rey C & Vignoles M (1991) Carbonate ions in apatites: Infrared investigations in the ?4 CO3 domain. Calcified Tissue International 49, 269-274.
    8. Elliott JC (1994) Structure and Chemistry of the Apatites and Other Calcium Orthophosphates. Elsevier, Amsterdam.
    9. Jahnke RA (1984) the synthesis and solubility of carbonate fluorapatite. American Journal of Science 290, 58-78.
    10. Kumar D (1980) Calcination of phosphate rocks. Chemie Ingenieur Technik 52, 736740.
    11. LABARTHE JC, Bonel G & MONTEL G (1973) Annales de Chimie Paris 8, 289-301.
    12. Lafon JP, Champion E & Assollant DB (2002) Caractrisation d'apatites phosphocalciques arbonates. Matriaux.
    13. Legeros RZ (1967) Ph.D., Thesis, New York University.
    14. Legeros RZ, Legeros JP, Trautz OR & Klein E (1964) Journal of Dental Research 43, 75.
    15. Lehr JR, McClellan GH, Smith JP & Frazier AW (1972) Phosphates dans l'agriculture: Colloque international sur les phosphates minraux solides, Toulouse.
    16. McConnell D (1973) Apatite: its Crystal Chemistry, Min-eralogy, Utilization, and Geologic and Biologic Occurrences, Springer-Verlag, Berlin.
    17. Memminger GG, Waggaman WH & Whitney WT (1930) the calcination or enrichment of phosphate rock. Journal of Industrial and Engineering Chemistry 22, 443446.
    18. Ozer AK (2003) the characteristics of phosphate rock in a fluidized bed for the upgrading. Advanced Powder Technology 14, 3342.
    19. SLACK AV (1968) PHOSPHORIC ACID, MARCEL DEKKER. INC, NEW YORK, and Volume I, Part I, 129.
    20. Trombe JC, Bonel G & Montel G (1967) Comptes Rendus de l'Acadmie des Sciences Series C 265, 1113.
    21. Trombe JC (1973) Contribution l'tude de la dcomposi-tion et de la ractivit de certaines apatites hydroxyles et carbonates. Annales de Chimie 8, 251-269.
    22. Vignoles M (1984) Contribution ltude des apatites carbonates de type B. Thse dtat. Toulouse.
    23. Vignoles C (1973) Thse de 3me cycle, Universit Paul Sabatier de Toulouse.
    25. Young RA (1973) Colloque International CNRS, Paris 230, 21.




Article ID: 1664
DOI: 10.14419/ijac.v2i1.1664

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