Thermal dehydration kinetics of phosphogypsum


  • F. A. López Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC)
  • H. Tayibi Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC)
  • I. García-Díaz Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC)
  • F. J. Alguacil Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC)



Phosphogypsum, Kinetics, Dehydration, Thermal behavior, Cement


Phsophogypsum is a by-product from the processing phosphate rock. Before the use of it in cement industry such as setting regulator is necessary a study of dehydration reaction of phosphogypsum to avoid the false setting during the milling. The aim is to study the thermal behavior of two different phosphogypsum sources (Spain and Tunisia) under non-isothermal conditions in argon atmosphere by using Thermo-Gravimetriy, Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DSC). DSC experiments were carried out at temperatures ranging from ambient to 350 °C at different heating rates. The temperatures of conversion from gypsum to hemihydrate and anhydrite states and heat of dehydration were determined. Various methods were used to analyze the DSC data for reaction kinetics determination. The activation energy and frequency factor were calculated for dehydration of phosphogypsum. Activation energy values of the main dehydration reaction of phosphogypsum were calculated to be approximately 61–118 kJ/mol.


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1. Pérez-López, R.; Nieto, J.M.; López-Coto, I; Aguado, J.L.; Bolivar, J.P.; Santisteban, M. (2010). Dynamics of contaminants in phophogypsum or the fertilizer industry of Huelva (SW Spain): From phosphate rock ore to the environment. Appl. Geochem., 25 [5], 705–715.

2. Rutherford, P.M.; Dudas, M.J.; Samek, R.A. (1994) Environmental impacts of phosphogypsum. Sci. Tot. Environ. 149 [1, 2], 1–38.

3. Tayibi, H.; Choura, M.; López, F.A.; Alguacil, F.J.; López-Delgado, A. (2009) Environmental impact and management of phosphogypsum. J. Environ. Manag. 90 [8], 2377–2386. PMid:19406560

4. Kuryatnyk, T.; Angulski da luz, C.; Ambroise, J.; Pera, J. (2008) Valorization of phosphogypsum as hydraulic binder. J. Hazard. Mat. 160 [2–3], 681–687. PMid:18433998

5. Mas, J.L.; San Miguel, E.G.; Bolívar, J.P.; Vaca, F.; Pérez-Moreno, J.P. (2006) An assay on the effect of preliminary restoration tasks applied to a large TENORM wastes disposal in the South-West of Spain. Sci Tot. Environ. 364 [1–3], 55–66. PMid:16343599

6. Papastefanou, C.; Stoulos, S.; Ioannidou, A.; Manolopoulou, M. (2006) The application of phosphogypsum in agriculture and the radiological impact. J. Environ. Radioact. 89 [2], 188–189. PMid:16806608

7. Garrido, F.; Illera, V.; García-Gonzalez, M.T. (2005) Effect of the addition of gypsum and lime rich industrial by-products on Cd, Cu and Pb availability and leachability in metal-spiked acid soils. Appl. Geochem. 20 [2], 397–408.

8. Abril, J.M.; García-Tenorio, R.; Periá-ez, R.; Enamorado, S.M.; Andreu, L.; Delgado, A. (2009) Occupational dosimetric assessment (inhalation pathway) from the application of phosphogypsum in agriculture in South West Spain. J. Environ. Radioact. 100, 29–34. PMid:19019506

9. Potgieter, J.H.; Potgieter, S.S.; McCrindle, R.I.; Strydom, C.A. (2003) An investigation into the effect of various chemical and physical treatments of a South African phosphogypsum to render a suitable as a set retarder for cement. Cem. Concr. Res. 33 [8], 1223–1227.

10. Altun, I.A.; Sert, Y. (2004) Utilization of weathered phosphogypsum as set retarder in Portland cement. Cem. Concr. Res. 34, 677–680.

11. Garg, M.; Jain, N.; Singh, M. (2009) Development of alfa plaster from phosphogypsum for cementitious materials. Constr. Build. Mater. 23 [10], 3138–3143.

12. Garg, M.; Jain, N. (2010) Waste gypsum from intermediate dye industries for production of building materials. Constr. Build. Mater. 24 [9], 1632–1637.

13. Kacimi, L.; Simon-Masseron, A.; Ghomari, A.; Derriche, Z. (2006) Reduction of clinkerization temperature by using phosphogypsum. J. Hazard. Mat. 137 [1], 129–13. PMid:16533556

14. Elkhadiri, I.; Diouri, A.; Boukhari, A.; Puertas, F.; Vázquez, T. (2003) Obtaining a sulfoaluminate belite cement by industrial waste. Mater. Construcc. 53 [270], 57–69.

15. El-Alfi, E.-S.A. (2004) Sulfoaluminate-belite cement from limestone, phosphogypsum and other waste product. Stud. Technol. 12, 928–935.

16. Karagözöztürk, A.; Oguz, H. (2004) The formation of alite phase by using phosphogypsum and oil shale. Cem. Concr. Res. 34 [11], 2079–2082.

17. Taher, M.A. (2007) Influence of thermally treated phosphogypsum on the properties of Portland slag cement. Resour. Conservat. Recycl. 52 [1], 28–38.

18. Coruh, S.; Ergun, N.O. (2010) Use fly ash, phosphogypsum and red mud as a linear material for the disposal of hazardous zinc leach residue waste. J. Hazard. Mat. 173 [1–3], 468–473. PMid:19762146

19. Shen, W.; Zhou, M.; Ma, W.; Hu, J.; Cai, Z. (2009) Investigation on the application of steel slag-fly ash-phosphogypsum solidified material as road base material. J. Hazard. Mat. 164 [1], 99–104.

20. Yang, J.; Liu, W.; Zhang, L.; Xiao, B. (2009) Preparation of load-bearing building materials from autoclaved phosphogypsum. Constr. Build. Mat. 23 [2], 687–693.

21. Lea's, (1998) P.C. Hewlett (Ed.), Lea's Chemistry of Cement and Concrete 4th ed. Arnold, London, 83–85.

22. Cruz, I.; Vázquez, T.; Fernandez-Pe-a, O. (1983) Sulfatos en el cemento Portland y su incidencia sobre el falso fraguado: Estado actual del conocimiento. Mater. Construcc. 192, 43–55.

23. Taylor H.F.W.; Cement Chemistry, 2nd ed., Thomas Telford Publishing, (1997), 84. PMid:8986747

24. Mantell, D.G. (Ed.), PPC: The Manufacure, Properites and Applicatoins of Portland Cements, Cement Additives and Blended Cements 1991, PPC Johannesburg, pp. 13 and 14.

25. Strydom, C.A.; Hudson-Lamb, D.L.; Potgieter, J.H.; Dagg, E. (1995) The thermal dehydration of synthetic gypsum. Thermochim. Acta. 269/270, 631–638.

26. Papageorgiou, A.; Tzouvalas, G.; Tsimas, S.; (2005) Use of inorganic setting retarders in cement industry. Cem. Concr. Compos., 27 [2], 183–189.

27. Charola, A.E.; Puhringer, J.; Steiger, M. (2007) Gypsum: a review of its role in the deterioration of building materials. Environ. Geol. 52 [2], 339–52.

28. Ballirano, P.; Melis, E. (2009) Thermal behaviour and kinetics of dehydration of gypsum in air from in situ real-time laboratory parallel beam X-ray powder diffraction. Phys. Chem. Mineral. 36 [7], 391–402.

29. Friedman, H. (1964) Kinetics of thermal degradation of char-forming plastics from thermogravimetry. Application to a phenolic plastic. J Polym Sci Part C. 6,183–195.

30. Flynn, J.H.; Wall, L.A. (1966) A quick, direct method for the determination of activation energy from thermogravimetric data. Polym. Lett. 4 [5],323–328.

31. Ozawa, T. (1965) A new method of analyzing thermogravimetric data. Bull. Chem. Soc. Jpn. 38, 1881–1886.

32. Doyle, C.D. (1961) Kinetic analysis of thermogravimetric data. J. Appl. Polym. Sci. 5 [15], 285–292.

33. Standard Test Method for Arrhenius Kinetic Constants for Thermally Unstable Materials Using Differential Scanning Calorimetry and the Flynn/Wall/Ozawa Method, American Society for Testing and Materials (ASTM) E698, 2011.

34. Coats, A.W.; Redfern, J.P. (1964) Kinetic parameters from thermogravimetric data. Nature. 201, 68–6.

35. Ma, L.; Ning, P.; Zheng, S.; Nui, X.; Zhang, W.; Du, Y. (2010) Reaction mechanism and kinetic analysis of the decomposition of phosphogypsum via solid-state reaction. Ind. Ing. Chem. Res. 49 [8], 3597–3602.

36. Strydom, C.A.; Potgieter, J.H. (1999) Dehydration behaviour of a natural gypsum and phosphogypsum during milling. Thermochim. Acta. 332 [1], 89–96.

37. López, F.A.; Gázquez, M.; Alguacil, F.J.; Bolívar, J.P.; García-Díaz, I.; López-Coto, I. (2011) Microencapsulation of phosphogypsum into a sulfur polymer matrix: Physico-chemical and radiological characterization. J. Hazard. Mat. 192 [1], 234–245.

38. Cárdenas-Escudero, C.; Morales-Flórez, V.; Pérez-López, R; Santos, A; Esquivias, L. (2011) Procedure to use phosphogypsum industrial waste for mineral CO2 sequestration. J. Hazard. Mat. 196, 431–435. . PMid:21982535

39. Sebbahi, S.; Lemine, M.; Sahban, F.; Aride, J.; Benarafa, L.; Belkbir, L. (1997) Thermal behaviour of Moroccan phosphogypsum. Thermochim. Acta. 302 [1–2], 69–75.

40. Manzello, S.L.; Gann, R.G.; Kukuck, S.R.; Prasad, K., Jones, W. (2007) Fire performance of a non-load-bearing steel stud gypsum board wall assembly: experiments and modeling. Fire and Mat. 31, 297–310.

41. Deutsch, Y.; Nathan, Y.; Sarig, S. (1994) Thermogravimetric evaluation of the kinetics of the gypsum-hemihydrate-soluble anhydrite transition. J. Therm. Anal. Calorim. 42 [1], 159–174.

42. Putnis, A.; Winkler, B.; Fernandez-Diaz, L. (1990) In situ IR spectroscopic and thermogravimetric study of the dehydration of gypsum. Mineral Mag. 54, 123–138

11. Dos Santos, V.A.; Pereira, J.A.F.R.; Dantas, C.C. (1997) Kinetics of thermal dehydration of gypsum ore for obtaining beta hemihydrate in a fluidized bed. Bull Soc. Chim. Belg. 6, 253–60.

44. Chang, H.; Huang, P.J.; Hou, S.C. (1999) Application of thermo-Raman spectroscopy to study dehydration of CaSO4_2H2O and CaSO4_0.5H2O. Mater. Chem. Phys. 58 [1], 12–9.

45. Prasad, P.S.R.; Chaitanya, V.K.; Prasad, K.S.; Rao, D.N. (2005) Direct formation of the c-CaSO4 phase in dehydration process of gypsum: in situ FTIR study. Am. Mineral. 90 [4], 672–678.

46. Ball, M.; Norwood, L.S. (1969) Studies in the system calcium sulphate water. Part I. Kinetics of dehydration of calcium sulphate dehydrate. J. Chem. Soc. A. 1633–1637.

47. Badens, E.; Llewellyn, P.; Fulconis, J.M.; Jourdan Veesler, C.S.; Boistelle, R. (1998) Study of gypsum dehydration by controlled transformation rate thermal analysis (CRTA). J. Solid State Chem. 139 [1], 37–44.

48. Lou, W.; Guan, B.; Wu, Z. (2011) Dehydration behaviour of FGD gypsum by simultaneous TG and DSC analysis. J. Therm. Anal. Calorim. 104 [2], 661–669.

49. Hudson-Lamb, D.L.; Strydom, C.A.; Potgieter, J.H. (1996) The thermal dehydration of natural gypsum and pure calcium sulphate dehydrate (gypsum). Thermochim. Acta. 282/283 [SPEC. ISS.], 483–492.

50. Elbeyli, I.K.; Piskin, S. (2004) Kinetic study of the thermal dehydration of phosphogypsum. J. Hazard. Mater. 116 [1–2], 111–117. PMid:15561369

51. Kontogeorgos, D.A.; Founti, M.A. (2012) Gypsum board reaction kinetics at elevated temperatures. Thermochim. Acta. 529 [10], 6–13.



How to Cite

López, F. A., Tayibi, H., García-Díaz, I., & Alguacil, F. J. (2015). Thermal dehydration kinetics of phosphogypsum. Materiales De Construcción, 65(319), e061.



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