Mathematical Simulation of Acid Concentration Effects during Acid Nitric Leaching of Cobalt from a Mixed Cobalt-Copper Oxide

Cobalt was acid nitric leached from a mixed cobaltcopper oxide with variable acid concentration. Resulting experimental data were used to analyze effects of increase in acid concentration, based on a shrinking core model of the process. The mathematical simulation demonstrated that the time rate of the dissolution mechanism is an increasing function of acid concentration. It was also shown that the magnitude of the acid concentration effect is time dependent and the increase in acid concentration is more effective at earlier stage of the dissolution than at later stage. The remaining process parameters are comprehensively affected by acid concentration and their interaction is synergetic.

Authors:

• Ek Ngoy
• A F Mulaba-Bafubiandi

Keywords:

• Acid effect
• Cobalt
• Cobalt-copper oxide
• Leaching
• Simulation

References:

[1] Baba A.A. and Adekola F.A., 2010. Hydrometallurgical processing of a
Nigerian sphalerite in hydrochloric acid: Characterization and
dissolution kinetics. Hydromet. 101,69-75
[2] Beolchni F., Petrangeli Papini M., Toro L., Trfoni M., Vegli├▓ F., 2001.
Acid leaching of manganiferrous ores by sucrose: kinetics modelling
and related statistical analysis. Min. Eng. 14(2), 175-184.
[3] Bingöl D., Canbazo─ƒlu M., 2004. Dissolution kinetics of malachite in
sulphuric acid. Hydromet. 72, 159-165
[4] Bingöl D., Canbazo─ƒlu M., Aydo─ƒan S., 2005. Dissolution kinetics of
malachite in ammonia/ammonium carbonate leaching. Hydromet. 76,
55-62
[5] Cengiz Özmetin, Muhtar Kocakerim M., Sinan Yapıcı, and Ahmet
Yartaşi, 1996. A Semi empirical Kinetic Model for Dissolution of
Colemanite in Aqueous CH3COOH Solutions. Ind. Eng. Chem. Res. 35,
2355-2359.
[6] Das G.K., Acharya S., Anand S., and Das R.P., 1995. Acid pressure
leaching of nickel-containing chromite overburden in the presence of
additives. Hydromet. 39, 17-128
[7] Emin Arzutug M., Muhtar Kocakerim M., Copur M., 2004. Leaching of
malachite ore in NH3-saturated water. Ind. Eng. Chem. Res. 43, 4118-
4123.
[8] Evangelos D. Economou, and Vaimakis T.C., 1997. Beneficiation of
Greek Calcareous Phosphate Ore Using Acetic Acid Solutions. Ind. Eng.
Chem. Res. 36,1491-1497
[9] Gharabaghi M., Irannajad M., Noaparast M., 2010. A review of the
beneficiation of calcareous phosphate ores using organic acid leaching.
Hydromet. 103, 96-107.
[10] Habbache N., Alane N., Djerad S. and Tifouti L., 2009. Leaching of
copper oxide with different acid solutions. Chem. Eng. J., 152(2-3), pp.
503-508
[11] Huseyin Okur, Taner Tekin, Kader Ozer A., 2002. Effect of ultrasound
on the dissolution of colemanite in H2SO4. Hydromet. 67, 79-86
[12] Minting Li, Chang Wei, Shuang Qiu, Xuejiao Zhou, Cunxiong Li,
Zhigan Deng, 2010. Kinetics of vanadium dissolution from black shale
in pressure acid leaching. Hydromet. 104, 193-200
[13] Nizamettin Demirkran, 2008. A study on dissolution of ulexite in
ammonium acetate solutions. Chem. Eng. J. 141, 180-186
[14] Oudene P.D., Olson F.A., 1983. Leachcing kinetics of malachite in
ammonium carbonate solutions. Metall. trans. B 14B: 33.
[15] Senanayake G., Das G.K. 2004. A comparative study of leaching
kinetics of limonitic laterite and synthetic iron oxides in sulfuric acid
containing sulfur dioxide. Hydromet. 72, 59-72.
[16] Tao Jiang, Yongbin Yang, Zhucheng Huang, Bin Zhang, Guanzhou
Qiu, 2004. Leaching kinetics of pyrolusite from manganese-silver ores
in the presence of hydrogen peroxide. Hydromet. 72, 129-138
[17] K.G. Fisher, 2011 "Cobalt processing development," 6th Southern
African Base Metals Conference, SAIMM
[18] Levenspiel, O., 1999. Chemical reaction engineering Wiley, New York
[19] Wen C.Y., 1968. Non catalytic heterogeneous solid fluid reaction
models. Ind. Eng. chem. 60(9), 34-54
[20] Phiri T.R., 2005. Leaching of cobalt bearing mineral from a
heterogeneous cobalt-copper mixed oxide. Extraction Metallurgy BTech
project, University of Johannesburg.