Journal of thermal analysis

, Volume 37, Issue 5, pp 945–951 | Cite as

Preparation and characterisation of magnesium sulphate heptahydrate from Kimberlite tailings

  • B. R. Reddy
  • S. Acharya
  • S. Anand
  • R. P. Das


Weathered Kimberlite tailings of Panna Diamond Mines were characterised by DTA and XRD techniques. The XRD pattern shows the presence of serpentine, quartz, calcite, hematite, magnetite and anatase phases. DTA curve indicates first endothermic peak at 125‡C due to dehydration of the mineral and second endo peak at 670‡C due to dehydroxylation of serpentine closely followed by an exothermic peak at 810‡C associated with the formation of forsterite. XRD and DTA studies of sulphuric acid leach residue of the Kimberlite shows the disappearance of serpentine phase with the appearance of CaSO4·2H2O phase. The product MgSO4·7H2O obtained after purification and crystallisation. From the optical emission spectroscopic analysis, the product was found to contain Ca, Fe and SiO2 as trace impurities.


Serpentine CaSO4 Forsterit Magnesium Sulphate Heptahydrate 
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Mittels DTA und Röntgendiffraktion wurden verwitterte Kimberlit-AbgÄnge aus Diamantbergwerken in Panna charakterisiert. Das Röntgendiagramm zeigt die Gegenwart von Serpentin-, Quarz-, Kalzit-, HÄmatit-, Magnetit- und Anatas-Phasen. Die DTA-Kurve zeigt einen ersten endothermen Peak bei 125‡C (Dehydratation des Minerales) und einen zweiten endothermen Peak bei 670‡C (Dehydroxylierung von Serpentin), eng gefolgt von einem exothermen Peak bei 810‡C (Bildung von Forsterit). Röntgendiffraktionsund DTA-Untersuchungen an einem schwefelsauren Extraktionsauszug von Kimberlit zeigen das Verschwinden der Serpentin-Phase, aber das zusÄtzliche Auftreten einer CaSO4·2H2O-Phase. Nach Reinigung und Kristallisation wurde MgSO4·7H2O als Produkt erhalten, dessen optische emissionsspektroskopische Untersuchung in Spuren Verunreinigungen mit Ca, Fe und SiO2 zeigten.


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  1. 1.
    K. C. Sahoo and S. Venkatesan, Proc. Int. Symp. Beneficiation and Agglomeration, Bhubaneswar, India, I2.2 (1986) 436.Google Scholar
  2. 2.
    P. Kresten and D. K. Paul, Can. Mineral., (1976) 487.Google Scholar
  3. 3.
    D. K. Paul, D. C. Rex and P. G. Harris; Geo. Soc. Amer. Bull, 86 (1975) 364.Google Scholar
  4. 4.
    S. P. Dasgupta and S. Phukan, Geo. Surv. India Misc. Publ., 19 (1971) 114.Google Scholar
  5. 5.
    E. H. Grohmann and M. Gill, Austrian Patent 1, 560, 658 (Feb. 6, 1980); M. Grill and H. Grohmann, Brit. Patent 2,23,563 (Jan. 3, 1980); J. J. Ruiz, U. S. Patent, 3, 402, 017 (Oct. 22, 1965).Google Scholar
  6. 6.
    G. Gabra, Hydrometall., 13 (1984) 1.Google Scholar
  7. 7.
    K. Othmer, Encyclopedia of Chemical Technology, 3rd edn., 14 (1987) 629.Google Scholar
  8. 8.
    R. N. Shreve and J. A. Jr. Brink, Chemical Process Industries, McGraw-Hill, KogaKusha Ltd., Tokyo 1977.Google Scholar
  9. 9.
    G. Gabra, M. Nagamori and J. J. Panneton, CIM Bull, 75 (1982) 156.Google Scholar
  10. 10.
    Chemical Engineers Handbook, Ed. J. H. Perry, 4th edn., (1963) 19.Google Scholar

Copyright information

© Wiley Heyden Ltd., Chichester and Akadémiai Kiadó, Budapest 1991

Authors and Affiliations

  • B. R. Reddy
    • 1
  • S. Acharya
    • 1
  • S. Anand
    • 1
  • R. P. Das
    • 1
  1. 1.Regional Research LaboratoryBhubaneswarIndia

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