Dissolution Kinetics and Leaching of Rutile Ore in Hydrochloric Acid

Alafara A. Baba, Folahan A. Adekola, Emmanuela E. Toye, Rafiu B. Bale

Department of Chemistry, University of Ilorin, P.M.B 1515, Ilorin-Nigeria..
Department of Geology and Mineral Sciences, University of Ilorin, P.M.B 1515, Ilorin-Nigeria..

DOI: 10.4236/jmmce.2009.810068                

Abstract

Experiments on the dissolution kinetics and leaching of rutile ore by hydrochloric acid have been carried out. The influence of acid concentration, temperature, stirring speed and particle diameter on the leaching of the ore were examined. The dissolution rates were greatly influenced by the hydrogen ion concentration, temperature, stirring speed and particle diameter. Kinetic data analysis showed that the dissolution mechanism followed a diffusion controled shrinking core model with the surface chemical reaction as the rate controlling step. The study showed that with 4M HCl solution, about 82.3 % of 10g rutile ore per litre of leachant at 80oC was dissolved within 120min., using 0.045-0.075mm particle diameter at a stirring speed of 360rpm. The reaction order with respect to hydrogen ion concentration was found to be 1.0, while 42.28kJ/mol was calculated for the activation energy of the dissolution process. Finally, the Xray diffraction spectrum showed that the residual solid which amounted to 18% of the initial solid material contained silica (a-SiO₂) and are formed around the shrinking core of the unreacted material.

Keywords

Dissolution, Leaching, Hydrochloric Acid

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	W .A. Deer, R. A. Howie and J. Zussman An introduction to the Rock-forming minerals. 2nd ed., Longman, England, 1992, 548-551.
[2]	C. Ikpat and N. H. Ibanga Nigeria’s mineral resources: A case for resource control. Raw Materials Res. and Dev. Council, Abuja-Nigeria. 2005 Special Publication, 2005, 17-33.
[3]	A .I. Ogbonna, S. M. Nwakandu and O. O. Onyemaobi. Strategic mineral deposits in Nigeria. Proceedings of the Nigerian Metallurgical Society, Abuja-Nigeria, 1999, 59-62.
[4]	Mineral Information Institute. 2009. http://www.mii.org. Retrieved on 13/06/2009.
[5]	D. Ulrike. The surface of Titanium-dioxide. Surface Science Reports.2005, 48(5-8), 53-59.
[6]	A. O. Adebayo, K. O. Ipinmoroti and O. O. Ajayi Leaching of sphalerite with Hydrogen peroxide and Nitric acid. J. Min and Mat. Characterization and Engr., 2006, 5(2), 167-177.
[7]	G. Ucar. Kinetics of spahlerite dissolution by sodium chlorate in hydrochloric acid. Hydrometallurgy, 2009, 96, 39-43.
[8]	E. O. Olanipekun. A kinetic study of the leaching of a Nigerian ilmenite ore by hydrochloric acid. Hydrometallurgy, 1999, 53, 1-10.
[9]	W. O. Siyanbola, A. Y. Fasasi, I. I. Funtua, O. M. Afolabi, T. A. Adesiyan and A. R. Adetunji. Elemental composition of rutile from South-western Nigeria using X-ray techniques. Nuclear instruments and methods in Physics Research. Section B, 2004, 215 (1-2), 240-245.
[10]	A. A. Baba, F. A. Adekola, O. I Dele-ige and R.B. Bale. Investigation of dissolution Kinetics of a Nigerian Tantalite ore in Nitric acid. J. Min. and Mat. Characterization and Engr.2007, 7(1), 83-95.
[11]	O. Levenspiel. Chemical Reaction Engineering 2nd ed., Wiley, New York, 1972, 359-368.
[12]	S. Aydogan, M. Erdemoglu, G. Ucar and A. Aras. Kinetics of galena dissolution in nitric acid solutions with hydrogen peroxide. Hydrometallurgy.2007, .88, 52-57.
[13]	A.A. Baba, F. A. Adekola and R.B. Bale. Development of a combined pyro- and hydrometallurgical route to treat spent zinc-carbon batteries. J. Hazardous materials. 2009, 171(1-3), 838-844. DOI: 10.1016/j.jhazmat. 2009.06.068
[14]	T. Tsuchida, E. Narita, H. Takuechi, M. Adachi, T. Okabe. .Manufacture of high pure titanium (IV) oxide by the chloride process: I. Kinetic Study on leaching of ilmenite ore in concentrated hydrochloric acid solution. Bull. Chem. Soc., Japan, 1982, .55(6), 1934-1938. In: E. Olanipekun Hydrometallurgy, 1999 53, 1-10.
[15]	M. M. Antonijevic, Z. D. Jankovic and M. D. Dimitrijevic. Kinetics of chalcopyrite dissolution by hydrogen peroxide in sulphuric acid. Hydrometallurgy, 2004, 71(3-4), 329-334.
[16]	A. A. Baba, F. A. Adekola and R. B. Bale. Study of dissolution kinetics of a Nigerian Cassiterite ore by hydrochloric acid. Science Focus, 2009, 14(2), 198-207.