Carbothermic Reduction of Mechanically Activated Mixtures of Celestite and Carbon

The effect of dry milling on the carbothermic reduction of celestite was investigated. Mixtures of celestite concentrate (98% SrSO4) and activated carbon (99% carbon) was milled for 1 and 24 hours in a planetary ball mill. Un-milled and milled mixtures and their products after carbothermic reduction were studied by a combination of XRD and TGA/DTA experiments. The thermogravimetric analyses and XRD results showed that by milling celestite-carbon mixtures for one hour, the formation temperature of strontium sulfide decreased from about 720°C (in un-milled sample) to about 600°C, after 24 hours milling it decreased to 530°C. It was concluded that milling induces increasingly thorough mixing of the reactants to reduction occurring at lower temperatures

Authors:

• N.Setoudeh
• M. Ali Askari Zamani
• N.J.Welham

Keywords:

• Activated carbon
• Celestite
• Ball milling
• Carbothermic reduction
• Strontium sulfide.

References:

[1] F., Habashi, Handbook of extractive metallurgy, vol. IV,Wiley VCH,
Germany, pp.2329-2336, 1997.
[2] J.A. Ober, Minerals Yearbook - Strontium, U.S. Geological Survey,
73.1-73.5, 2006.
[3] W. Chen, and Y. Zhu, "Preparation of strontium carbonate from
celestite," Miner. Process. Extr. Metall. (Trans. Inst. Min. Metall. C)
vol.109, pp. C1-C5, 2000.
[4] R.S. Sonawane, B.B. Kale, S.K. Apte, and M.K. Dongare, "Effect of
catalyst on the kinetics of reduction of celestite (SrSO4 by active
charcoal," Metall. Mater. Trans., vol. 31B, pp. 35-41, 2000.
[5] M. Erdemoglu, and M. Canbazoglu, "leaching of SrS with water and the
precipitation of SrCO3 from leach solution by different carbonating
agents," Hydrometallurgy, vol. 49, pp.135-150, 1998.
[6] G. Owusu, and J.E. Litz, "Water leaching of SrS and precipitation of
SrCO3 using carbon dioxide as precipitating agent," Hydrometallurgy,
vol. 57, pp. 23-29, 2000.
[7] M. Iwai, and M. Toguri, "The leaching of celestite in sodium carbonate
solution," Hydrometallurgy, vol. 22, pp. 87-100, 1989.
[8] F.R. Carrillo-Pedroza, A. Uribe-Salas, and A.H. Castillejos-Escobar, "A
laboratory study of the leaching of celestite in a Pachuca tank," Miner.
Eng., vol. 8, pp. 495-509, 1995.
[9] A.H. Castillejos-Escobar, F.P. De La Cruz-De Bosque, and A. Uribe-
Salaa, "The direct conversion of celestite to strontium carbonate in
sodium carbonate aqueous media," Hydrometallurgy, vol. 40, pp. 207-
22, 1996.
[10] R. Suarez-Orduna, J.C. Rendon-Angeles, and K. Yanagisawa, "Kinetic
study of the conversion of mineral celestite to strontianite under alkaline
hydrothermal conditions," Int. J. Miner.Process., vol.83, pp. 12-18,
2007.
[11] M. Erdemoglu, M. Sarikaya, and M. Canbazoglu, "Leaching of Celestite
with Sodium Sulfide," J. Dispers. Sci. Technol., vol. 27, pp. 439-442,
2006.
[12] M. Erdemoglu, M. Canbazoglu, and H. Yalcin, "Carbothermic reduction
of high-grade celestite ore to manufacture strontium carbonate," Miner.
Process. Extr. Metall. (Trans. Inst. Min. Metall. C) vol. 107, pp. C65-
C70, 1998.
[13] M. Erdemuglu, "Carbothermic reduction of mechanically activated
celestite," Int. J. Miner. Process. , vol. 92, pp. 144-152, 2009.
[14] HSC Chemistry for Windows, version 5.1., Outokumpu, Oy, 1994.
[15] N.J. Welham, "Formation of micronized WC from scheelite (CaWO4),"
Mater. Sci. Eng., vol A 248, pp. 230-237, 1998.
[16] N.J. Welham, "Mechanical enhancement of the carbothermic formation
of TiB2," Metall. Mat. Trans., vol. 31A, pp. 283-289, 2000,
[17] N.J. Welham, "Activation of the carbothermic reduction of magnesium
ore," Int. J. Miner. Process. vol. 67, pp. 187-198, 2002.
[18] S. Raygan, J.V. Khaki, and M.R. Aboutalebi, "Effect of mechanical
activation on the packed-bed, high temperature behavior of hematite and
graphite mixture in air," J. Mater. Synth. Process. vol. 10, pp. 113-120,
2002.
[19] N. Setoudeh, A.Saidi, and N.J.Welham, "Carbothermic recution of
anatase and rutile," J. Alloys Compd., vol. 390, pp. 138-143, 2005.