ELECTRON THEORY OF METALS REDUCTION: THEORY AND METHODS OF METALS EXTRACTION FROM VARIOUS TYPES OF ORE

The present work analyzes the existing mechanism of solid-phase metals reduction from oxides. It was shown that the existed mechanisms of reduction do not explain the diversity of the practical results leading to a generally accepted opinion that there is no single uniform reduction mechanism. This study presents the results of the solid-phase reduction of metals from lump magnetite, siderite, titanomagnetite and chromite types of ore by carbon from various deposits. The obtained results were compared with the results of reduction of chromium, silicon and aluminum by carbon from pure oxides. Change in the electrical characteristics and analysis of the processes of electron- and mass transfer under reducing conditions were performed to clarify the general theoretical concepts of reduction mechanism. It has been concluded that there is general process of transformation of the crystal lattice of oxide into the crystal lattice of metal for reduction of different metals. The positions of electron theory for solid-phase reduction of metals from crystal lattice of oxides were developed using the basic concepts of chemistry, solid state physics about imperfect crystals, quantum mechanics and character of electron distribution and transfer in metals and ionic semiconductors. The theory embraces all the known results of reduction with formation of metal on the surface of high-grade lump ore, nucleation of metal inside of the complex and low-grade types of ore and formation and sublimation of suboxides. Major ideas of the developing theory of electron reduction have been formulated on the basis of metals reduction as a result of the exchange of electrons between the reducing agent and metal cations in oxides by means of the charged anion vacancies formed on the surface and their scattering in the volume. The transformation of the cations’ ionic bond in oxides into metallic bond of the metal phase on the surface (or inside of the oxide lattice) occurs without the displacement of the cations over significant distances and thermodynamic difficulties for the formation of metallic nucleus when the charged anion vacancies merge (skipping the stage of formation of the atoms of metal). There might be no direct contact between the metal and the reducing agent in case of formation of the metal phase inside of the oxide volume. As a result, harmful impurities from the reducing agent, e.g. carbon and sulphur, do not penetrate into iron during reduction of complex and low-grade types of ore. Therefore, for the reduction of iron from such an ore, it is possible to utilize a low-quality reducing agent, e.g. steam coal. The selective solid-phase reduction of iron from lump complex ore makes it possible to obtain a metal-oxide composite material containing pure DRI and valuable oxides which are difficult for reduction, i.e. oxides of magnesium, titanium and vanadium.

1. Pavlov M.A. Vospominaniya metallurga: Ch. 1, 2 [Memories of a metallurgist: Parts 1,2]. Moscow: Metallurgizdat, 1943, 288 p. (In Russ.).

2. Rostovtsev S.T. Teoriya metallurgicheskikh protsessov [Theory of metallurgical processes]. Moscow: Metallurgizdat, 1956, 515 p. (In Russ.).

3. Gel’d P.V. Mechanism of oxides reduction by solid carbon. Uspekhi khimii. 1957, vol. XXVI, no. 9, pp. 1070–1086. (In Russ.).

4. Chufarov G.I., Tatievskaya E.A. Adsorption-catalytic theory of metals oxide reduction. In: Sb. Problemy metallurgii [Issues of metallurgy]. Moscow: izd. AN SSSR, 1953, pp. 15–32. (In Russ.).

5. Chufarov G.I., Zhuravleva M.G., Balakirev V.F., Men’ A.I. State of reduction theory of metal oxides. In: Sb. Mekhanizm i kinetika vosstanovleniya metallov [Mechanism and kinetics of metals reduction]. Moscow: Nauka, 1970, pp. 7–15. (In Russ.).

6. Chufarov G.I., Men’ A.N., Balakirev V.F. etc. Termodinamika protsessov vosstanovleniya okislov metallov [Thermodynamics of me tal oxides reduction]. Moscow: Metallurgiya, 1970, 399 p. (In Russ.).

7. Rostovtsev S.T., Simonov V.K., Ashin A.K., Kostelov O.L. Mechanism of carbothermic reduction of metal oxides. In: Sb. Mekhanizm i kinetika vosstanovleniya metallov [Mechanism and kinetics of metals reduction]. Moscow: Nauka, 1970, pp. 24–31. (In Russ.).

8. Gruner L. Etudes sur les hauts-formeause. In: Annales des Mines. 1872, pp. 1–14. (In Fr.).

9. Edstrom J.O. The mechanism of reduction of iron oxides. Journal of the Iron and Steel Institute. 1953, vol. 17, no. 3, p. 289.

10. Tleugabulov S.M. Teoriya i tekhnologiya tverdofaznogo vosstanovleniya zheleza uglerodom [Theory and technology of solid-phase reduction of iron by carbon]. Alma-Ata: Gylym, 1991, 312 p. (In Russ.).

11. Vignes A. Extractive Metallurgy 2. Metallurgical Reaction Processes. London: Ltd, 2011, 355 p.

12. Habashi F. Handbook of extractive metallurgy. Vol. I: The Metal Industry. Ferrous Metals. Wiley, 1997, 488 p.

13. Pavlov V.V. Nesoobraznosti metallurgii: monografiya [Inconsistencies in metallurgy: Monograph]. Ekaterinburg: Izd-vo UGTU, 2013, 212 p. (In Russ.).

14. Yusfin Yu.S., Pashkov N.F. Metallurgiya zheleza [Metallurgy of iron]. Moscow: Akademkniga, 2007, 464 p. (In Russ.).

15. Chernobrovin V.P., Pashkeev I.Yu., Mikhailov G.G. etc. Teoreticheskie osnovy protsessov proizvodstva uglerodistogo ferrokhroma iz ural’skikh rud: Monografiya [Theoretical foundations of production of carbon ferrochromium from the Ural Ores: Monograph]. Chelyabinsk: Izd-vo YuUrGU, 2004, 346 p. (In Russ.).

16. Senin A.V. Solid phase reduction of chrome ore by methane. Elektrometallurgiya. 2013, no. 1, pp. 31–37. (In Russ.).

17. Senin A.V., Pashkeev I.Yu., Mikhailov G.G. “Gas-solid-phase” mechanism for the reduction of ore materials. In: Trudy nauchnoprakticheskoi konferentsii “Perspektivy razvitiya metallurgii i mashinostroeniya s ispol’zovaniem zavershennykh fundamental’nykh issledovanii i NIOKR: FERROSPLAVY” [Proceedings of the Sci.-Pract. Conf.”Prospects for the Development of Metallurgy and Mechanical Engineering with the Use of Completed Basic Research and RTD: Ferroalloys”]. Ekaterinburg: Al’fa Print, 2018, pp. 72–80. (In Russ.).

18. Ryabchikov I.V., Mizin V.G., Yarovoi K.I. Reduction of iron and chromium from oxides by carbon. Steel in Translation. 2013, no. 6, pp. 379–382.

19. Elyutin V.P., Pavlov Yu.A., Polyakov V.P., Sheboldaev B.V. Vzaimodeistvie okislov metallov s uglerodom [Interaction of metal oxides with carbon]. Moscow: Metallurgiya, 1976, 359 p. (In Russ.).

20. Kulikov I.S. Reduction mechanism of oxides of iron, manganese, silicon and chromium. In: Mekhanizm i kinetika vosstanovleniya metallov: Sb. nauchn. tr. [Mechanism and kinetics of metals reduction: Coll. of sci. papers]. Moscow: Nauka, 1970, pp. 19–24. (In Russ.).

21. Tleugabulov S.M., Abikov S.B., Koishina G.M., Tatybaev M.K. Fundamentals and Prospects of the Development of Reduction Steelmaking. Russian Metallurgy (Metally). 2018, no. 2, pp. 72–77.

22. Kolchin O.P. On mechanisms of metals reduction from their oxides by carbon. In: Mekhanizm i kinetika vosstanovleniya metallov: Sb. nauchn. tr. [Mechanism and kinetics of metals reduction: Coll. of sci. papers]. Moscow: Nauka, 1970, pp. 40-48. (In Russ.).

23. Zhukhovitskii A.A., Shvartsman L.A. Fizicheskaya khimiya [Physical chemistry]. Moscow: Metallurgiya, 1976, 520 p. (In Russ.).

24. Roshin A.V., Roshin V.E. Thermal reducing dissociation and sublimation – the stages of the transformation of oxside lattices into metal lattices. Russian Metallurgy (Metally). 2006, no. 1, pp. 1–7.

25. Roshin V.E., Roshin A.V., Berdnikov A.A., Goikhenberg Yu.N. Formation and sublimation of the intermediate products of the reduction of silicon from its dioxide. Russian Metallurgy (Metally). 2008, no. 4, pp. 281–285.

26. Roshchin A.V., Goikhenberg Yu.N., Ryabukhin A.G. Crystallochemical transformations in aluminum oxides under reductive heating. Izvestiya. Ferrous Metallurgy. 2006, no. 8, pp. 6–9. (In Russ.).

27. Roshin A.V., Roshin V.E., Ryabukhin A.G., Goikhenberg Yu.N. Role of the silicate phase of an enclosing rock in the prereduction of disseminated chromium ores. Russian Metallurgy (Metally). 2007, no. 4, pp. 261–267.

28. Roshin A.V., Roshin V.E., Ryabukhin A.G. electrical conduction and mass transfer in crystalline oxides. Russian Metallurgy (Metally). 2006, no. 3, pp. 193–198.

29. Fistul’ V.I. Fizika i khimiya tverdogo tela: uchebnik dlya vuzov. T. 1 [Physics and chemistry of the solid state: Textbook for universities: vol. 1]. Moscow: Metallurgiya, 1995, 480 p. (In Russ.).

30. Gorelik S.S., Dashevskii M.Ya. Materialovedenie poluprovodnikov i dielektrikov: uchebnik dlya vuzov [Material science of semiconductors and dielectrics: Textbook for universities]. Moscow: MISiS, 2003, 480 p. (In Russ.).

31. Bokshtein B.S., Yaroslavtsev A.B. Diffuziya atomov i ionov v tverdykh telakh [Diffusion of atoms and ions in solids]. Moscow: MISiS, 2005, 362 p. (In Russ.).

32. Burdett J. K. Chemical bonds: a Dialog. John Wiley & Sons, 1997.

33. Ponomarev L.I. Pod znakom kvanta: uchebnoe posobie dlya vuzov [Under the sign of the quantum: Manual for universities]. Moscow: Fizmatlit, 2007, 416 p. (In Russ.).

34. Tsirel’son V.G. Kvantovaya khimiya: uchebnik dlya vuzov [Quantum chemistry: Textbook for universities]. Moscow: BINOM, 2014, 245 p. (In Russ.).

35. Roshchin V.E., Roshchin A.V. Physical foundation of selective reduction of metals in crystal lattice of complex oxides. Izvestiya. Ferrous Metallurgy. 2013, no. 5, pp. 44–54. (In Russ.).

36. Roshchin V.E., Roshchin A.V. Selective Reduction of metals in the lattice of a complex oxide. Russian Metallurgy (Metally). 2013, no. 3, pp. 169–175.

37. Roshchin V.E., Roshchin A.V. Physics of the solid phase oxidation and reduction of metals. Russian Metallurgy (Metally). 2015, no. 5, pp. 354–359.

38. Li K. etc. Iron extraction from oolitic iron ore by a deep reduction process. Journal of iron and steel research international. 2011, vol. 18, no. 8, pp. 9–13.

39. Kapelyushin Y., Xing X., Zhang J., Sasaki Y., Ostrovski O. Effect of alumina on the gaseous reduction of magnetite in CO/CO2 gas mixtures. Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science. 2015, vol. 46, no. 3, pp. 1175–1185.

40. Kapelyushin Y., Sasaki Y., Zhang J., Jeong S., Ostrovski O. In-Situ study of gaseous reduction of magnetite doped with alumina using high-temperature XRD analysis. Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science. 2015, vol. 46, no. 6, pp. 2564–2572.

41. Cullough S., Hockaday S., Johnson C., Barcza N.A. Pre-reduction and smelting characteristics of Kazakhstan ore samples. The Twelfth Int. Ferroalloys Congress Sustainable Future. Helsinki, Finland. 2010, pp. 249–262.

42. Anacleto N.M., Solheim I., Sørensen B., Ringdalen E., Ostrovski O. Reduction of chromium oxide and ore by methane-containing gas mixtures. Authors’ Revised Draft Infacon XV: International FerroAlloys Congress, Southern African Institute of Mining and Metallurgy, Cape Town, 25–28 February 2018.

43. Leikola M., Taskinen P., Eric R.H. Reduction of Kemi chromite with methane. Authors’ Revised Draft Infacon XV: International Ferro-Alloys Congress, Southern African Institute of Mining and Metallurgy, Cape Town, 25–28 February 2018. Edited by R.T. Jones, P. den Hoed, & M.W. Erwee.

44. Sokhanvaran S., Paktunc D., Barnes A. NaOH–assisted direct reduction of Ring of Fire chromite ores, and the associated implications for processing. Authors’ Revised Draft Infacon XV: International Ferro-Alloys Congress, Southern African Institute of Mining and Metallurgy, Cape Town, 25–28 February 2018. Edited by R.T. Jones, P. den Hoed, & M.W. Erwee.

45. Bhalla A., Eric R.H. Mechanism and kinetic modelling of methanebased reduction of Mamatwan manganese ore. Infacon XV: Int. Ferro-Alloys Congress, Southern African Institute of Mining and Metallurgy, Cape Town, 25–28 February 2018. Edited by R.T. Jones, P. den Hoed, & M.W. Erwee.

46. Cheraghi A., Yoozbashizadeh H., Safarian J. Chemical, microstructural, and phase changes of manganese ores in calcination and pre-reduction by natural gas. Infacon XV: Int. Ferro-Alloys Congress, Southern African Institute of Mining and Metallurgy, Cape Town, 25–28 February 2018. Edited by R.T. Jones, P. den Hoed & M.W. Erwee.

47. Kalenga M.K., Pan X. Pre-reduction of a South African manganese ore: more insight on the formation of phases. Infacon XV: International Ferro-Alloys Congress, Southern African Institute of Mining and Metallurgy, Cape Town, 25–28 February 2018. Edited by R.T. Jones, P. den Hoed, & M.W. Erwee.

48. Petrus H.T.B.M., Putera A.D.P., Sugiarto E., Perdana I., Warmada I.W., Nurjaman F., Astuti W., Mursito A.T. Kinetics on roasting reduction of limonitic laterite ore using coconut-charcoal and anthracite reductants. Minerals Engineering. 2019, no. 132, pp. 126–133.

49. Li Y.-J., Sun Y.-S., Han Y.-X., Gao P. Coal-based reduction mechanism of low-grade laterite ore. Transactions of Nonferrous Metals Society of China (English Edition). 2013, vol. 23, no. 11, pp. 3428–3433.

50. Roshchin V.E., Asanov A. V., Roshchin A.V. Possibilities of twostage processing of titaniferrous magnetite ore concentrates. Russian Metallurgy (Metally). 2011, no. 6, pp. 499–508.

51. Salikhov S.P., Roshchin A.V., Roshchin V.E. Theoretical aspects of pyrometallurgical processing of sideroplesite ore. Chernye Metally. 2018, no. 8, pp. 13–18.

52. Quader M. A. etc. A comprehensive review on energy efficient CO2 breakthrough technologies for sustainable green iron and steel manufacturing. Renewable and Sustainable Energy Reviews. 2015, vol. 50, pp. 594–614.

53. Sohn H.Y. Suspension ironmaking technology with greatly reduced energy requirement and CO2 emissions. Steel Times International. 2007, vol. 31, no. 4, pp. 68–72.

54. Milford R.L., Pauliuk S., Allwood J.M., Muller D.B. The roles of energy and material efficiency in meeting steel industry CO2 targets. Environmental Science and Technology. 2013, vol. 47, no. 7, pp. 3455–3462.