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Novel Technology for Chlorination of Niobium and Tantalum Oxides and Their Low-Grade Ore Concentrates

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ABSTRACT
A novel energy-economic and environmentally benign technological procedure for chlorination of niobium and tantalum oxides as well as their low-grade ore concentrates was elaborated. The process is based on using carbon tetrachloride or silicon tetrachloride as a chlorinating agent under pressure. It proceeds at moderate temperatures and is free from the shortcomings of conventional carbochlorination processes such as the use of chlorine gas at very high temperatures and formation of toxic products and ozone depleting agents (phosgene, carbon monoxide, chlorohydrocarbons).
 
Cite this paper
B. Shainyan, Y. Danilevich, Y. Garmazov, A. Finkelstein, T. Aisueva and V. Turchaninov, "Novel Technology for Chlorination of Niobium and Tantalum Oxides and Their Low-Grade Ore Concentrates," Journal of Minerals and Materials Characterization and Engineering, Vol. 7 No. 2, 2008, pp. 163-173.
 
References
[1]Mehra, O. K., Zahed H. S., and Jena, P. K., 1966, “Kinetics of the chlorination of niobium pentoxide with chlorine in presence of excess graphite powder” Trans. Indian Inst. Met., Vol. 19, pp. 53-56.
 
[2]Mehra, O. K., and Jena, P. K., 1967, “Kinetics of the chlorination of tantalum-pentoxide with chlorine in the presence of excess graphite powder”, Trans. Indian Inst. Met., Vol. 20, pp. 210-212.
 
[3]Meubus, P., 1979, “High temperature chlorination kinetics of a niobium pyrochlore”, Metall. Trans., Vol. 10B, No. 1, pp. 93-101.
 
[4]Ruiz, M. del C., Gonzalez, J., and Rivarola, J., 1997, “Carbochlorination of Argentinian tantalo-columbites”, Canad. Metallurg. Quart., Vol. 36, No. 2, pp. 103-110.
 
[5]Gonzalez, J., Gennari, F., Bohé, A., Ruiz, M. del C., Rivarola, J., and Pasquevich, D. M., 1998, “Chlorination of a niobium and tantalum ore”, Thermochim. Acta, Vol. 311, No. 1-2, pp. 61-69.
 
[6]Gonzalez, J., Gennari, F., Ruiz, M. del C., Bohé, A., and Pasquevich, D. M., 1998, “Kinetics of the carbochlorination of columbite”, Trans. Instn. Min. Metall. (Sect. C: Mineral Process. Extr. Metall.), Vol. 107, pp. 130-138.
 
[7]Gonzalez, J., Bohé, A., Pasquevich, D. M., and Ruiz, M. del C., 2002, “β-Ta2 O5 carbochlorination with different types of carbon”, Canad. Metallurg. Quart., Vol. 41, No. 1, pp. 29-40.
 
[8]Ruiz, M. del C., Gonzalez, J., and Rivarola, J., 2004, “Kinetics of chlorination of tantalum pentoxide in mixture with sucrose carbon by chlorine gas”, Metall. Mater. Trans., Vol. 35B, No. 3, pp. 439-448.
 
[9]Allain, E., Djona, M., and Gaballah, I., 1997, “Kinetics of chlorination and carbochlorination of pure tantalum and niobium pentoxides”, Metall. Mater. Trans., Vol. 28B, No. 2, pp. 223-233.
 
[10]Gaballah, I., Allain, E., and Djona, M., 1997, “Extraction of tantalum and niobium from tin slags by chlorination and carbochlorination”, Metall. Mater. Trans., Vol. 28B, No. 3, pp. 359-369.
 
[11]Jena, P.K., Brocchi, E. A., and Garcia, R.I., 1997, “Kinetics of chlorination of niobium pentoxide by carbon tetrachloride”, Metall. Mater. Trans., Vol. 28B, No. 1, pp. 39-45.
 
[12]Jena, P. K., Brocchi, E. A., and Lima, M.P.A.C., 2001, “Studies on the kinetics of carbon tetrachloride chlorination of tantalum pentoxide”, Metall. Mater. Trans., Vol. 32B, No. 5, pp. 801-810.
 
[13]Chernykh, V.P., RF Patent No. 2033415. 1995. Bull. izobr. No. 11.
 
[14]Garmazov, Yu. L., Turchaninov, V. K., Danilevich, Yu. S., and Shainyan, B. A., RF Patent No. 2292301. 2007. Bull. izobr. No. 3.
 
[15]Garmazov, Yu. L., Turchaninov, V. K., Danilevich, Yu. S., and Shainyan, B. A., RF Patent No. 2292302. 2007. Bull. izobr. No. 3.
 
[16]Chase, M. W., Jr., 1998, NIST-JANAF Themochemical Tables, 4th Ed. J. Phys. Chem. Ref. Data, Monograph 9, 1951 pp.
 
[17]Chernyshev, E. A., Krasnova, T. L., Sergeev A. P., and Abramova, E. S., 1997, “Siloxanes as sources of silanones”, Russ. Chem. Bull., Vol. 46, No. 9, pp. 1586-1589.
 
[18]Ignatov, S. K., Sennikov, P. G., Razuvaev, A. G., Chuprov, L. A., Schrems, O., and Ault, B. S., 2003, “Theoretical study of the reaction mechanism and role of water clusters in the gas-phase hydrolysis of SiCl4”, J. Phys. Chem., Vol. 107A, No. 41, pp. 8705-8713.
 
[19]Arai, S., Sudo, Y., and Nishida, A., 2005, “Niobium pentachloride-silver perchlorate as an efficient catalyst in the Friedel-Crafts acylation and Sakurai-Hosomi reaction of acetals”, Tetrahedron, Vol. 61, No. 19, pp. 4639-4642.
 
[20]Narsaiah, A.V., Sreenu, D., and Nagaiah, K., 2006, “Efficient synthesis of β-amino alcohols catalyzed by niobium pentachloride: regioselective ring opening of epoxides with aromatic amines”, Synth. Commun., Vol. 36, No. , pp. 3183-3189.
 
[21]Fried, H. E., and Johnson, T. H., US Patent No. 5066829. Publ. 19.11.1991.
 
[22]Masuda, T., Isobe, E., Higashimura, T., and Takada, K., 1983, “Poly[1-(trimethylsilyl)-1-propyne]: a new high polymer synthesized with transition-metal catalysts and characterized by extremely high gas permeability”, J. Am. Chem. Soc., Vol. 105, No. 25, pp. 7473-7474.                                                          eww150209lx
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