Abstract
A kinetic model for the batch leaching of various metals using different lixiviants was developed. The overall material balances for the reactants and products at the solid/liquid interface were formulated for various types of heterogeneous reactions at the interface. The solutions to these mass balances are identified analytically, as well as numerically. Applications of these numerical solutions to various leaching systems using rotating discs or powders are discussed. The metal-dissolution systems addressed include cobalt, nickel and copper in acid, cyanide and ammoniacal solutions.
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Abbreviations
- a, b, c, d:
-
Stoichiometric coefficients for reaction (1)
- β:
-
ratio of a/c
- CAb:
-
Concentration of reactant A in the bulk solution
- CAs:
-
Interfase concentration of reactant A
- CBs:
-
Interfase concentration of reactant B
- CDs:
-
Concentration of product D at the interphase
- Cpb:
-
Concentration of product P in the bulk solution
- Cps:
-
Concentration of product P at the interphase
- C0ps:
-
Initial concentration of product P at the interphase
- C0Ab:
-
Initial concentration of product P in the bulk solution
- Di:
-
Diffusivity of i species
- d:
-
diameter of particulate
- Kmi, kmA:
-
Mass transfer coefficients of i and A, respectively
- km1, km2:
-
As given in the text
- kmr, kmp:
-
Mass transfer coefficients of reactants and products
- kf:
-
Forward rate constant
- kb:
-
Backward rate constant
- k1, k2:
-
As given in the text
- l, m, q, x:
-
Reaction orders of Eq. (1) with respect to individual species
- A, B:
-
Reactant species
- D, P:
-
Product species
- M, G:
-
Integral constants as defined in Eq. (4)
- M′:
-
Metal substrate, solid reactant
- n:
-
V/v
- R:
-
Percentage of km1 contributing to the overall rate
- S:
-
Surface area of solid metal; t Leaching time
- v:
-
Volume of the bulk solution
- vs:
-
Slip velocity
- δ:
-
Thickness of diffusion boundary layer
- δ′:
-
Thickness of interface
- θ:
-
The fraction of surface unavailable for the reaction; ν Kinematic viscosity of fluid
- ω:
-
Angular velocity of rotating disc.
References
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SME Preprint 94–29, SME Annual Meeting, Feb. 14–17, 1994, Albuquerque, NM.
M&MP paper 94–618. Discussion of this peer-reviewed and approved paper is invited and must be submitted, in duplicate, prior to Aug. 31, 1995.
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Meng, X., Sun, X. & Han, K.N. A dissolution kinetic model for metals in solutions. Mining, Metallurgy & Exploration 12, 97–102 (1995). https://doi.org/10.1007/BF03403085
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DOI: https://doi.org/10.1007/BF03403085