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Thermal desulfurization of pyrite: An in situ high-T neutron diffraction and DTA–TGA study

Published online by Cambridge University Press:  04 June 2019

Hongwu Xu*
Affiliation:
Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Xiaofeng Guo
Affiliation:
Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Lani A. Seaman
Affiliation:
Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Aaron J. Harrison
Affiliation:
Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Stephen J. Obrey
Affiliation:
Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Katharine Page
Affiliation:
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

To study thermal desulfurization of pyrite (FeS2), we conducted in situ neutron diffraction experiments in the temperature range 298–1073 K. On heating, pyrite remained stable up to 773 K, at which it started to decompose into pyrrhotite (Fe1−xS) and S2 gas. Rietveld analysis of the neutron data from 298 to 773 K allowed determination of the thermal expansion coefficient of pyrite (space group Pa$\bar 3$) to be αV = 3.7456 × 10−5 K−1, which largely results from the expansion of the Fe–S bond. With further increase in temperature to 1073 K, all the pyrite transformed to pyrrhotite (Fe1−xS) at 873 K. Unit-cell parameters of Fe1−xS (space group P63/mmc) increase on heating and decrease on cooling. However, the rates in cell expansion are larger than those in contraction. This hysteresis behavior can be attributed to continuous desulfurization of pyrrhotite (i.e., x in Fe1−xS decreases) with increasing temperature until the stoichiometric troilite (FeS) was formed at 1073 K. On cooling, troilite underwent a magnetic transition to an orthorhombic structure (space group Pnma) between 473 and 573 K. In addition, using differential thermal analysis (DTA) and thermogravimetric analysis (TGA) implemented with a differential scanning calorimeter, we performed kinetic measurements of pyrite decomposition. Detailed peak profile and Arrhenius (k = A exp(−Ea/RT)) analyses yielded an activation energy Ea of 302.3 ± 28.6 kJ/mol (based on DTA data) or 302.5 ± 26.4 kJ/mol (based on TGA data) and a ln(A) of 35.3 ± 0.1.

Type
Invited Paper
Copyright
Copyright © Materials Research Society 2019 

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Footnotes

b)

Present address: Department of Chemistry, Washington State University, Pullman, Washington 99164, USA.

References

Vaughan, D.J.: Sulfide mineralogy and geochemistry. (Rev. Mineral. Geochem. Volume 61, Mineralogical Society of America, Chantilly, VA, 2006) 714 pp.CrossRefGoogle Scholar
Lin, Z. and Quvarfort, U.: Predicting the mobility of Zn, Fe, Cu, Pb, Cd from roasted sulfide (pyrite) residues—A case study of wastes from the sulfuric acid industry in Sweden. Waste Manage. 16, 671 (1996).CrossRefGoogle Scholar
Hiskey, J. and Pritzker, M.: Electrochemical behavior of pyrite in sulfuric acid solutions containing silver ions. J. Appl. Electrochem. 18, 484 (1988).CrossRefGoogle Scholar
Barnard, A.S. and Russo, S.P.: Shape and thermodynamic stability of pyrite FeS2 nanocrystals and nanorods. J. Phys. Chem. C 111, 11742 (2007).CrossRefGoogle Scholar
Hu, G., Dam-Johansen, K., Wedel, S., and Hansen, J.P.: Decomposition and oxidation of pyrite. Prog. Energy Combust. Sci. 32, 295 (2006).CrossRefGoogle Scholar
Deng, J., Wen, S., Chen, X., Xian, Y., and Wu, D.: Dynamic simulation of the thermal decomposition of pyrite under vacuum. Metall. Mater. Trans. A 45, 2445 (2014).CrossRefGoogle Scholar
Hurst, H.J., Levy, J.H., and Warne, S.S.J.: The application of variable atmosphere thermomagnetometry to the thermal decomposition of pyrite. React. Solids 8, 159 (1990).CrossRefGoogle Scholar
Lambert, J.M., Simkovich, G., and Walker, P.L.: The kinetics and mechanism of the pyrite-to-pyrrhotite transformation. Metall. Mater. Trans. B 29, 385 (1998).CrossRefGoogle Scholar
Bhargava, S.K., Garg, A., and Subasinghe, N.D.: In situ high-temperature phase transformation studies on pyrite. Fuel 88, 988 (2009).CrossRefGoogle Scholar
Xu, H., Zhao, Y., Vogel, S.C., Daemen, L.L., and Hickmott, D.D.: Anisotropic thermal expansion and hydrogen bonding behavior of portlandite: A high-temperature neutron diffraction study. J. Solid State Chem. 180, 1519 (2007).CrossRefGoogle Scholar
Xu, H., Zhao, Y., Zhang, J., Hickmott, D.D., and Daemen, L.L.: In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature. Phys. Chem. Miner. 34, 223 (2007).CrossRefGoogle Scholar
Xu, H.W., Zhao, Y.S., Vogel, S.C., Hickmott, D.D., Daemen, L.L., and Hartl, M.A.: Thermal expansion and decomposition of jarosite: A high-temperature neutron diffraction study. Phys. Chem. Miner. 37, 73 (2010).CrossRefGoogle Scholar
Xu, H.W., Costa, G.C.C., Stanek, C.R., and Navrotsky, A.: Structural behavior of Ba1.24Al2.48Ti5.52O16 hollandite at high temperature: An in situ neutron diffraction study. J. Am. Ceram. Soc. 98, 255 (2015).CrossRefGoogle Scholar
Xu, H.W., Zhao, Y.S., Hickmott, D.D., Lane, N.J., Vogel, S.C., Zhang, J.Z., and Daemen, L.L.: High-temperature neutron diffraction study of deuterated brucite. Phys. Chem. Miner. 40, 799 (2013).CrossRefGoogle Scholar
Hong, Y. and Fegley, B. Jr.: The kinetics and mechanism of pyrite thermal decomposition. Ber. Bunsenges. Phys. Chem. 101, 1870 (1997).CrossRefGoogle Scholar
Andresen, A.F.: Magnetic phase transitions in stoichiometric FeS studied by means of neutron diffraction. Acta Chem. Scand. 14, 919 (1960).CrossRefGoogle Scholar
Wang, H. and Salveson, I.: A review on the mineral chemistry of the non-stoichiometric iron sulphide, Fe1−xS (0 ≤ x ≤ 0.125): Polymorphs, phase relations and transitions, electronic and magnetic structures. Phase Transitions 78, 547 (2005).CrossRefGoogle Scholar
Marshall, W.G., Nelmes, R.J., Loveday, J.S., Klotz, S., Besson, J.M., Hamel, G., and Parise, J.B.: High-pressure neutron-diffraction study of FeS. Phys. Rev. B 61, 11201 (2000).CrossRefGoogle Scholar
Baranov, N.V., Ibrahim, P.N.G., Selezneva, N.V., Kazantsev, V.A., Volegov, A.S., and Shishkin, D.A.: Crystal structure, phase transitions and magnetic properties of pyrrhotite-type compounds Fe7−xTixS8. Phys. B 449, 229 (2014).CrossRefGoogle Scholar
Li, F. and Franzen, H.F.: From pyrrhotite to troilite—An application of the Landau theory of phase-transitions. J. Alloys Compd. 215, L3 (1994).CrossRefGoogle Scholar
Powell, A.V., Vaqueiro, P., Knight, K.S., Chapon, L.C., and Sanchez, R.D.: Structure and magnetism in synthetic pyrrhotite Fe7S8: A powder neutron-diffraction study. Phys. Rev. B 70, 014415, 1 (2004).CrossRefGoogle Scholar
Tenailleau, C., Etschmann, B., Wang, H., Pring, A., Grguric, B.A., and Studer, A.: Thermal expansion of troilite and pyrrhotite determined by in situ cooling (873 to 373 K) neutron powder diffraction measurements. Mineral. Mag. 69, 205 (2005).CrossRefGoogle Scholar
de Villiers, J.P.R. and Liles, D.C.: The crystal-structure and vacancy distribution in 6C pyrrhotite. Am. Mineral. 95, 148 (2010).CrossRefGoogle Scholar
King, H.E. Jr. and Prewitt, C.T.: High-pressure and high-temperature polymorphism of iron sulfide (FeS). Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 38, 1877 (1982).CrossRefGoogle Scholar
Andresen, A.F. and Torbo, P.: Phase transitions in FexS (x = 0.90–1.00) studied by neutron diffraction. Acta Chem. Scand. 21, 2841 (1967).CrossRefGoogle Scholar
Rietveld, H.: A profile refinement method for nuclear and magnetic structures. J. Appl. Crystallogr. 2, 65 (1969).CrossRefGoogle Scholar
Chrysta, S.B.: Thermal expansion of iron pyrites. Trans. Faraday Soc. 61, 1811 (1965).CrossRefGoogle Scholar
Selivanov, E.N., Vershinin, A.D., and Gulyaeva, R.I.: Thermal expansion of troilite and pyrrhotine in helium and air. Inorg. Mater. 39, 1097 (2003).CrossRefGoogle Scholar
Wendlandt, W.W.: Reaction kinetics by differential thermal analysis: A physical chemistry experiment. J. Chem. Educ. 38, 571 (1961).CrossRefGoogle Scholar
Kissinger, H.E.: Reaction kinetics in differential thermal analysis. Anal. Chem. 29, 1702 (1957).CrossRefGoogle Scholar
Coats, A.W. and Bright, N.F.H.: The kinetics of the thermal decomposition of pyrite. Can. J. Chem. 44, 1191 (1966).CrossRefGoogle Scholar
Charpentier, L. and Masset, P.J.: Thermal decomposition of pyrite FeS2 under reducing conditions. Mater. Sci. Forum 654–656, 2398 (2010).CrossRefGoogle Scholar
Li, R., Zhang, J., Tan, R., Gerdes, F., Luo, Z., Xu, H., Hollingsworth, J.A., Klinke, C., Chen, O., and Wang, Z.: Competing interactions between various entropic forces toward assembly of Pt3Ni octahedra into a body-centered cubic superlattice. Nano Lett. 16, 2792 (2016).CrossRefGoogle ScholarPubMed
Phillips, B.L., Xu, H., Heaney, P.J., and Navrotsky, A.: 29Si and 27Al MAS-NMR spectroscopy of β-eucryptite (LiAlSiO4): The enthalpy of Si,Al ordering. Am. Mineral. 85, 181 (2000).CrossRefGoogle Scholar
Zhu, J., Du, S., Yu, X., Zhang, J., Xu, H., Vogel, S.C., Germann, T.C., Francisco, J.S., Izumi, F., Momma, K., Kawamura, Y., Jin, C., and Zhao, Y.: Encapsulation kinetics and dynamics of carbon monoxide in clathrate hydrate. Nat. Commun. 5, 4128 (2014).CrossRefGoogle ScholarPubMed
Zhang, J., Celestian, A., Parise, J.B., Xu, H., and Heaney, P.J.: A new polymorph of eucryptite (LiAlSiO4), ε-eucryptite, and thermal expansion of α- and ε-eucryptite at high pressure. Am. Mineral. 87, 566 (2002).CrossRefGoogle Scholar
Xu, H., Navrotsky, A., Nyman, M.D., and Nenoff, T.M.: Thermochemistry of microporous silicotitanate phases in the Na2O–Cs2O–SiO2–TiO2–H2O system. J. Mater. Res. 15, 815 (2000).CrossRefGoogle Scholar
Neuefeind, J., Feygenson, M., Carruth, J., Hoffmann, R., and Chipley, K.K.: The Nanoscale ordered MAterials diffractometer NOMAD at the spallation neutron source SNS. Nucl. Instrum. Methods Phys. Res., Sect. B 287, 68 (2012).CrossRefGoogle Scholar
Larson, A.C. and Von Dreele, R.B.: General structure analysis system (GSAS); Los Alamos National Laboratory Report LAUR. 86–748, Los Alamos, NM, 2004, 224 pp.Google Scholar
Bayliss, P.: Crystal structure refinement of a weakly anisotropic pyrite. Am. Mineral. 62, 1168 (1977).Google Scholar
Alsén, N.: Röntgenographische Untersuchung der Kristallstrukturen von Magnetkies, Breithauptit, Pentlandit, Millerit und verwandten Verbindungen. Geol. Fören. Förh. 47, 19 (1925).CrossRefGoogle Scholar
Von Dreele, R.B., Jorgensen, J.D., and Windsor, C.G.: Rietveld refinement with spallation neutron powder diffraction data. J. Appl. Crystallogr. 15, 581 (1982).CrossRefGoogle Scholar
Guo, X., Ushakov, S.V., Labs, S., Curtius, H., Bosbach, D., and Navrotsky, A.: Energetics of metastudtite and implications for nuclear waste alteration. Proc. Natl. Acad. Sci. U. S. A. 111, 17737 (2014).CrossRefGoogle ScholarPubMed
Guo, X., Wu, D., Xu, H., Burns, P.C., and Navrotsky, A.: Thermodynamic studies of studtite thermal decomposition pathways via amorphous intermediates UO3, U2O7, and UO4. J. Nucl. Mater. 478, 158 (2016).CrossRefGoogle Scholar
Guo, X. and Xu, H.: Enthalpies of formation of polyhalite: A mineral relevant to salt repository. J. Chem. Thermodyn. 114, 44 (2017).CrossRefGoogle Scholar