Journal of Thermal Analysis and Calorimetry

, Volume 132, Issue 1, pp 143–154 | Cite as

Kinetics and mechanisms of the carbothermic reduction of chromite in the presence of nickel

  • Dawei Yu
  • Dogan Paktunc


Carbothermic reduction of chromite in the presence of nickel as the alloying element was investigated in a wide temperature range up to 1500 °C using thermogravimetric analysis coupled with continuous off-gas analysis (TG-DSC-MS). Both isothermal and non-isothermal linear heating tests were performed for the kinetic study with the calculation of activation energies. In order to further elucidate the reduction mechanism, the reduced products were characterized by SEM–EDS and XRD. It was concluded that the reduction sequence followed a multi-stage mechanism, reflected partly by the dependency of the activation energy on the extent of reduction. With the progress of reduction, refractory oxide layers gradually formed on/close to the surface of each chromite particle, causing the shift of the rate-limiting factor from chemical control to diffusion control. The promoting effect from the addition of Ni was evident at temperatures higher than 1300 °C due to the formation of alloys of lower melting point.


Chromite Ferrochrome Carbothermic reduction Alloying Kinetics 



The following contributions are acknowledged: Judith Price for the preparation of polished sections, Derek Smith for XRD analyses, Elizabeth Houghton and Khushmeet Gill for SEM analyses, and KWG Resources Inc. for providing the ore samples. The study was funded by NRCan under the Rare Earth Elements and Chromite R&D Program.


  1. 1.
    Slatter DD. Technological trends in chromium unit production and supply. INFACON 7; FFF, Trondheim, Norway; 1995. p. 249–62.Google Scholar
  2. 2.
    Murthy YR, Tripathy SK, Kumar CR. Chrome ore beneficiation challenges & opportunities—a review. Miner Eng. 2011;24:375–80.CrossRefGoogle Scholar
  3. 3.
    Johnson J, Reck BK, Wang T, Graedel TE. The energy benefit of stainless steel recycling. Energy Policy. 2008;36:181–92.CrossRefGoogle Scholar
  4. 4.
    Chakraborty D, Ranganathan S, Sinha SN. Investigations on the carbothermic reduction of chromite ores. Metall Mater Trans B. 2005;36B:437–44.CrossRefGoogle Scholar
  5. 5.
    Niayesh MJ, Dippenaar RJ. The solid state reduction of chromite. In: INFACON 6. Proceedings of the 6th international ferroalloy congress, Cape Town, South Africa; 1992. p. 57–63.Google Scholar
  6. 6.
    Ding YL, Warner NA. Kinetics and mechanism of reduction of carbon-chromite composite pellets. Ironmak Steelmak. 1997;24(3):224–9.Google Scholar
  7. 7.
    Perry KPD, Finn CWP, King RP. An ionic diffusion mechanism of chromite reduction. Metall Trans B. 1988;19B:677–84.CrossRefGoogle Scholar
  8. 8.
    Roschin AV, Karnoukhov VN, Roschin VE, Malkov NV. New findings in research of solid phase reactions in chromite ore reduction processes. In: Proceedings: tenth international ferroalloys congress, Cape Town, South Africa; 2004. p. 333–42.Google Scholar
  9. 9.
    Atasoy A, Sale FR. An investigation on the solid state reduction of chromite concentrate. Solid State Phenom. 2009;147–149:752–7.CrossRefGoogle Scholar
  10. 10.
    Murti NSS, Seshadri V. Kinetics of reduction of synthetic chromite with carbon. Trans ISIJ. 1982;22:925–33.CrossRefGoogle Scholar
  11. 11.
    Soykan O, Eric RH, King RP. The reduction mechanism of a natural chromite at 1416 °C. Metall Trans B. 1991;22B:53–63.CrossRefGoogle Scholar
  12. 12.
    Wang Y, Wang L, Xu J, Chou KC. Kinetics of carbothermic reduction of synthetic chromite. J Min Metall Sect B Metall. 2014;50(1):15–21.CrossRefGoogle Scholar
  13. 13.
    Hu X, Okvist LS, Yang Q, Bjorkman B. Thermogravimetric study on carbothermic reduction of chromite ore under non-isothermal conditions. Ironmak Steelmak. 2015;42(6):409–16.CrossRefGoogle Scholar
  14. 14.
    Nafziger RH, Tress JE, Paige JI. Carbothermic reduction of domestic chromites. Metall Trans B. 1979;10B:5–14.CrossRefGoogle Scholar
  15. 15.
    Kekkonen M, Xiao Y, Holappa L. Kinetic study on solid state reduction of chromite pellets. In: INFACON 7, Trondheim, Norway; 1995. p. 351–60.Google Scholar
  16. 16.
    Dawson NF. The solid state reduction of chromite (PhD thesis). Durban: University of Natal; 1989.Google Scholar
  17. 17.
    Dawson NF, Edwards RI. Factors affecting the reduction of chromite. Reio De Janeiro, Barzil: INFACON; 1986. p. 1–11.Google Scholar
  18. 18.
    Zhao B, Hayes PC. Effects of oxidation on the microstructure and reduction of chromite pellets. In: The twelfth international ferroalloys congress (INFACON XII), Helsinki, Finland; 2010. p. 263–73.Google Scholar
  19. 19.
    Kleynhans ELJ, Neizel BW, Beukes JP, Zyl PGV. Utilisation of pre-oxidized ore in the pelletised chromite pre-reduction process. Miner Eng. 2016;92:114–24.CrossRefGoogle Scholar
  20. 20.
    Ding YL, Warner NA. Catalytic reduction of carbon-chromite composite pellets by lime. Thermochim Acta. 1997;292:85–94.CrossRefGoogle Scholar
  21. 21.
    Apaydin F, Atasoy A, Yildiz K. Effect of mechanical activation on the carbothermal reduction of chromite with metallurgical coke. Can Metall Q. 2011;50(2):113–8.CrossRefGoogle Scholar
  22. 22.
    Lekatou A, Walker RD. Effect of SiO2 addition on solid state reduction of chromite concentrate. Ironmak Steelmak. 1997;24(2):133–43.Google Scholar
  23. 23.
    Weber P, Eric RH. Solid-state fluxed reduction of LG-6 chromite from the Bushveld complex. In: INFACON 6. Proceeding of the 6th international ferroalloys congress, Cape Town, South Africa; 1992. p. 71–7.Google Scholar
  24. 24.
    Weber P, Eric RH. The reduction mechanism of chromite in the presence of a silica flux. Metall Trans B. 1992;24(6):987–95.CrossRefGoogle Scholar
  25. 25.
    Weber P, Eric RH. The reduction of chromite in the presence of silica flux. Miner Eng. 2006;19:318–24.CrossRefGoogle Scholar
  26. 26.
    Duong HV, Johnston RF. Kinetics of solid state silica fluxed reduction of chromite with coal. Ironmak Steelmak. 2000;27(3):202–6.CrossRefGoogle Scholar
  27. 27.
    Deventer JSJV. The effect of additives on the reduction of chromite by graphite: an isothermal kinetic study. Thermochim Acta. 1988;127:25–35.CrossRefGoogle Scholar
  28. 28.
    Hu X, Teng L, Wang H, Okvist LS, Yang Q, Bjorkman B, et al. Carbothermic reduction of synthetic chromite with/without the addition of iron powder. ISIJ Int. 2016;56(12):2147–55.CrossRefGoogle Scholar
  29. 29.
    Hu X, Wang H, Teng L, Seetharaman S. Direct chromium alloying by chromite ore with the presence of metallic iron. J Min Metall Sect B Metall. 2013;49(2):207–15.CrossRefGoogle Scholar
  30. 30.
    Hu X, Yang Q, Okvist LS, Bjorkman B. Thermal analysis study on the carbothermic reduction of chromite ore with the addition of mill scale. Steel Res Int. 2015;86:1–9.CrossRefGoogle Scholar
  31. 31.
    Yape EO. Fe–Ni–Cr crude alloy production from direct smelting of chromite and laterite ores. J Med Bioeng. 2014;3(4):245–50.Google Scholar
  32. 32.
    Katayama HG, Tokuda M, Ohtani M. Promotion of the carbothermic reduction of chromite ore by the addition of borates. Iron Steel Inst Jpn. 1986;72(10):1513–20.CrossRefGoogle Scholar
  33. 33.
    Bale CW, Belisle E, Chartrand P, Decterov SA, Eriksson G, Gheribi AE, et al. FactSage Thermochemical Software and Database, 2010–2016. Calphad. 2016;54:35–53.CrossRefGoogle Scholar
  34. 34.
    Dresler W, McLean A. The extraction of ferrochromium in the presence of nickel from bird river chromite ores. Can Metall Q. 1992;31(3):181–8.CrossRefGoogle Scholar
  35. 35.
    Vyazovkin S, Burnham AK, Criado JM, Pérez-Maqueda LA, Popescu C, Sbirrazzuoli N. ICTAC Kinetics Committee recommendations for performing kinetic computations on thermal analysis data. Thermochim Acta. 2011;520(1–2):1–19. Scholar
  36. 36.
    Phillips WR. A differential thermal study of the chlorites. Mineral Mag. 1963;33(260):404–14.CrossRefGoogle Scholar

Copyright information

© Crown  2018

Authors and Affiliations

  1. 1.CanmetMININGNatural Resources CanadaOttawaCanada

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