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Kinetic studies of adsorption of palmitate and laurate soaps
onto some metal ores in aqueous media
Millicent
U.
Ibezim-Ezeani* and Alphonso C. I. Anusiem
Department
of Pure and Industrial Chemistry, University of Port
Harcourt, P. M. B. 5323, Choba, Port Harcourt, Nigeria.
*Corresponding author.
E-mail:
millibejmj@yahoo.com. Tel: +2347039450740.
Accepted 19 November, 2009 |
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The
kinetics of adsorption of sodium-palmitate and sodium-laurate
onto galena, hematite and cassiterite in aqueous media was
investigated at various concentrations, times and
temperatures. Experimental results were analysed using the
pseudo-first and pseudo-second order kinetic models. The
pseudo-first order model with higher correlation coefficient
values described the adsorption kinetics better than the
pseudo-second order model. The rate constant from the
pseudo-first order model [0.109 min-1 for galena,
0.102 min-1 for hematite, 0.085 min-1
for cassiterite (in the sodium-palmitate adsorption) and
0.127 min-1 for galena, 0.109 min-1
for hematite, 0.095 min-1 for cassiterite (in the
sodium-laurate adsorption) at 29oC] show these
rates in the order: galena > hematite > cassiterite for the
adsorbents; and sodium-laurate > sodium-palmitate for the
adsorbates. Some kinetic parameters were computed and the
values obtained indicate that the adsorption processes
occurred at reasonable rate, low temperature and low energy
suggesting physical adsorption as the dominant process.
Key words:
Kinetics, adsorption, soap, collector reagent, pseudo-first
order. |
