LEACHING KINETICS OF ZINC FROM SPHALERITE WITH ACIDIFIED SODIUM HYPOCHLORITE

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LEACHING KINETICS OF ZINIC.pdf (1.45 MB)

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2008-04-16

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Department Chemistry,Faculty of Natural and Applied Sciences, nasarawa state university keffi.

Abstract

Investigations on the kinetics leaching of zinc from sphalerite with sodium hypochlorite in hydrochloric acid were conducted. It is found that hydrochloric and hypochlorous acids concentration have significant effects on the leaching rate of zinc, with the reaction order with respect to the sodium hypochlorite is 0.65 and 0.52 for hydrochloric acid. Temperature has inverse relations on the leaching rate with apparent activation energy of 19 kJmol1 within the temperature range of 30 to 50°C. Decrease in particle size lead to increase in the leaching rates. Changes in the speed of agitation significantly affect the leaching rates. The leaching of zinc from sphalerite under these conditions was found to be diffusional - controlled and follows a shrinking core model. Employing a graphical and statistical methods, the following kinetic model including the effect of the above chosen parameters, was established: 1 + 2(1 - a) - 3(1 - = y” [NaOClfi5[HClf2 exp(-2280/T)t

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Sodium hypochlorite, leaching, kinetics, sphalerite

Citation

Houqen, L. R.; 1975 U. S. Pat 3880653, Jackson K. J.; Stricknland J. D. H. 1967. Dissolution of Pyrites ores in acid chloride solutions, a study of the common sulphide minerals; Tran., met. Soc. ASME, 239:1557 1564. jayi, O.O.; Oladipo, M.O. A.; Ogunsuyi, H.O.; Adebayo, A.0.2002. Determination of the minor and trace elements in Biriniwa's tin, pyrite and ornamental lead/zinc ore using neutron activation analysis. Bull. Chem. Soc. Ethioipia. 16:207-211. Jena, P. K.; Brocchi, E. A. 1992. Extraction of copper from dry Salobo (Brazil) chaleopyrite concentrate and aqueous slurries thereof by chlorination with Cl2 gas: Trans Instn. Min. Met tall (Sec C: mineral Processing Ext. metal), 101 (Jan. April 1992). llimarin, I.P., Fadeeva, V.I.; Dorokha, E.N (Translation Ad. Boris Spivakov). 1976. Lecture Experiments in Analytical Chemistry, Mir, Publishers, Moscow,. Kirk Orthner 1992. Encyclopaedia of Chemical Technology, 4,h edition Vol. 2 John Wiley, New York, 330 342. iswas, A. K(ed.), 1991. Frontiers in applied chemistry (2nd edn.) Narosa Publishing House, New Delhi, pp.39 Levenspiel, O. 1972. Chemical Reaction Engineering, John Wiley, NY (2ndEd.), 375. Pilgrim R. F.; Ingrahm T. R. 1967. Thermodynamic of the chlorination of iron cobalt, Nickel and Copper Sulphides; Can. Met. Quart; 6: 683-703. opur, M. 2001. Solubility of ZnS Concentrate containing pyrite and chaleopyrite in HN03 solutions Chem. Biochem. Egn. Quar. 15: 184 184 otton F. A.; Wilkinson G 1976. Advanced Inorganic Chemistry (4th edn.) Wiley Interscience & Sons,

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https://keffi.nsuk.edu.ng/handle/20.500.14448/5477

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