STUDY OF THE MOLYBDENUM CONCENTRATE ROASTING WITH LIME IN THE AIR ATMOSPHERE
Abstract
The oxidative roasting of a standard molybdenum concentrate with a Mo content of 54.7% in air in the presence of CaO at the temperature 450 – 600 °C has been studied. A flotation concentrate MKF-1 with a molybdenite content of 91.2% and a particle size of <5 μm - 51%, 5-10 μm - 46%, > 10 μm - 2% was used in the research. It has been established by XRD, TG, DTA and SEM-EDX that the process is exothermic and proceeds in the temperature range of 451 - 715 °C. Roasting is accompanied by the formation of a loose layer of CaMoO4 and CaSO4. Intermediate products are MoO3 and SO3. The process includes the stage of molybdenite oxidation with oxygen and the formation of MoO3 and SO2 vapors, the oxidation of SO2 to SO3, and the interaction of MoO3 and SO3 with CaO to obtain solid CaMoO4 and CaSO4. Analysis of the dependence of the transformation degree on time for a temperature of 450 – 600 °C showed that there is no linear dependence in the Arrhenius coordinates. It was concluded that at 450 - 500 °C the rate – controlling step is chemical kinetics. In the range 550 – 600 °C the process proceeds in a mixed mode, when the rates of internal diffusion and chemical reaction are comparable.
References
Voronov, Y.I., Zaiko V.P., Zhuchkov V.I. Technology of molybdenum ferroalloys. Ekaterinburg: UrO RAN. 2000. 267 р. (in Russian).
Lasheen T.A., El-Ahmady M.E., Hassib H.B., Helal A.S. Molybdenum Metallurgy Review: Hydrometallurgical Routes to Recovery of Molybdenum from Ores and Mineral Raw Materials. Min. Proc. Extract. Metal. Rev. 2015. V. 36. N 3. P. 145-173. DOI 10.1080/08827508.2013.868347.
Udoeva L.Yu., Selivanov E.N., Pikulin K.V. Organo-alkaline leaching of molybdenite concentrate. Tsvet. Metally. 2017. N 11. Р. 37 -42 (in Russian). DOI: 10.17580/tsm.2017.11.07.
Smirnov К.М., Raspopov N.А., Shneerson, Ya.М. Autoclave Leaching of Molybdenite Concentrates with Catalytic Additives of Nitric Acid. Russ. Metallurgy (Metally). 2010. N 7. P. 588-595. DOI: 10.1134/S0036029510070025.
Khoshnevisan A., Yoozbashizadeh H., Mozammel M., Sadrnezhaad S.K. Kinetics of pressure oxidative leaching of molibdenite concentrane by nitric acid. Hydrometallurgy. 2012. V. 111-112. N 1. P. 52-57. DOI: 10.1016/j.hydromet.2011.10.002.
Kholmogorov A.G., Kononova O.N. Processing mineral raw materialsin Siberia: oresofmolybdenium, tungsten, leadandgold. Hydrometallurgy. 2005. V. 76. P. 37-54. DOI: 10.1016/j.hydromet.2004.08.002.
Antonijeviс M.M., Pacoviс N.V. Investigation of molybdenite oxidation by sodium dichromate. Minerals Eng. 1992. V. 5. N 2. P. 223-233. DOI: 10.1016/0892-6875(92)90044-A.
Aleksandrov P.V., Medvedev A.S., Kadirov A.A., Imideev V.A. Processing molybdemum concentrate susing low-temperature oxidising-chlorinating roasting. Rus. J. Non-Ferrous Metals. 2014. V. 55. N 2. P. 114-119. DOI: 10.1007/s11015-021-01075-3.
Styazhkina E.N., Antropova I.G., Kashkak E.S., Khomoksonova D.P. The thechnology of processing low-quality rhenium-containing molybdenum concentrates. Sovr. Naukoemk. Tekhnol. 2015. N 12-1. P. 44-46 (in Russian).
Singh S.M., Chetty J.M., Juneja S.J.C., Gupta C.K. Studies on the processing of a low grade molybdenite con-centrate by lime roasting. Minerals Eng. 1988. N 1(4). Р. 337-342. DOI: 10.1016/0892-6875(88)90023-4.
Wang X.-W., Peng J., Wang M.-Y., Ye P.-H., Xiao Y. The role of CaO in the extraction of Ni and Mo from carbo-naceous shale by calcification roasting, sulfation roasting and water leaching. Int. J. Mineral Proc. 2011. V. 100. P. 130–135. DOI: 10.1016/j.minpro.2011.05.012.
Wang M., Wang X., Liu W. A novel technology of molyb-denum extraction from low grade Ni-Mo ore. Hydrometallurgy. 2009. V. 97. P. 126 – 130. DOI: 10.1016/j.hydromet.2008.12.004.
Gudkova I.Yu., Vusikhis A.S., Lempert D.B. Oxidative roasting of molybdenite concentrate with formation of calcium molybdate carried out in the mode of filtration combus-tion. Rus. Chem. Bull. 2016. V. 65. Р. 2396–2399. DOI: 10.1007/s11172-016-1595-5.
Kharin E.I., Khalezov B.D., Zelenin E.A. The development of environmentally friendly complex technology of molybdenic concentrate processing at South-Shameisky field. Izv. Vyssh. Uchebn. Zaved. Gornyi Zhurn. 2015. N 5. P. 129 – 134 (in Russian). DOI: 10.5772/60671.
Sokolova Yu.V., Chepikov A.N. Oxidative roasting of industrial spent catalysts Co-Mo/Al2O3 hydroprocessing with lime. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2020. V. 63. N 11. P. 57-64 (in Russian). DOI: 10.6060/ivkkt.20206311.6256.
Sokolova Yu.V., Bogatyreva E.V. Study of the kinetics of calcium molybdate leaching with sodium carbonate solutions. Tsvet. Metally. 2021. N 1. Р. 40–46 (in Russian). DOI: 10.17580/tsm.2021.01.05.
Shelekhov E.V., Sviridova T.A. Programs for x-ray analysis of polycrystals. Metalloved. Term. Obrab. Metallov. 2000. V. 42. P. 309-313 (in Russian). DOI: 10.1007/BF02471306.
Сhemical encyclopedia. Ed. by I.L. Knunyants. M.: Sov. Entsiklop. 1990. V. 2. 671 p. (in Russian).
Zelikman A.N. Metallurgy of refractory rare metals. M.: Metallurgiya. 1986. 440 p. (in Russian).
D'yachenko A.N. Chemical kinetics of heterogeneous processes. Tomsk: Izd-vo Tomsk. politekh. un-ta. 2014. 102 p. (in Russian).
Voldman G.M., Zelikman A.N. Theory of hydrometallurgical processes. M.: Intermet Inzhiniring. 2003. 464 p. (in Russian).
