Search published articles

Showing 4 results for A. Zakeri

A. Zakeri,, M. Sh. Bafghi, Sh. Shahriari,
Volume 4, Issue 3 (Summer &Autumn 2007 2007)

Abstract: In this paper, kinetics of reductive leaching of manganese dioxide ore by ferrous ion in sulfuric acid media has been examined. Experimental results show that increasing temperature from 20 to 60 °C and decreasing ore particle size from −16+20 to −60+100 mesh considerably enhance both the dissolution rate and efficiency. Molar ratios of Fe2+/MnO2 and H2SO4/MnO2 in excess to the stoichiometric amounts were needed for successful manganese dissolution. Under the optimum condition (ore particle size of −60+100 mesh, Fe2+/MnO2 molar ratio of 3.0, H2SO4/MnO2 molar ratio of 2.0) manganese could be extracted with over 95% efficiency by 20 minutes leaching at room temperature. A kinetic analysis based on dimensionless time method showed that shrinking core – ash diffusion control model fits the experimental results reasonably well. Value of activation energy was found to be 28.1 kJ/mole for the proposed mechanism.
A. H. Emami, M. Sh. Bafghi, J. Vahdati Khaki, A. Zakeri,
Volume 6, Issue 2 (Spring 2009 2009)


the changes of BET surface area of a mineral substance during intensive grinding process. Validity of the proposed

model was tested by the experiments performed using a natural chalcopyrite mineral as well as the published data. It

was shown that the model can predict the experimental results with a very good accuracy and can be used to predict

what may happen under the similar experimental conditions.

Based on experimental observations, a model has been developed to describe the effect of grinding time on Bafghi, A.h. Emami, A. Zakeri, J. Vahdati Khaki,
Volume 7, Issue 2 (Spring 2010 2010)


has been investigated. It has been shown that the mechanism of leaching reaction is diffusion through the product layer

and does not undergo any change as a result of mechanical activation in a wide range of experimental conditions.

Leaching rate is strongly influenced by milling intensity and the effect of ball to powder mass ratio is stronger than

milling time. Curve fitting of experimental data shows that leaching rate constant is approximately a linear function

of ball to powder mass ratio, while it obeys a power function with regard to the milling time.

The kinetics of chalcopyrite leaching in a ferric sulfate media for raw and mechanically activated samples

A. Karimbeigi, A. Zakeri, A. Sadighzadeh,
Volume 10, Issue 3 (September 2013)

Ni and Cu elemental powder mixtures containing 25, 50, and 75% at Cu were subjected to mechanical alloying in a planetary ball mill under various milling times. Structural evolution was analyzed by means of X-ray diffraction and scanning electron microscopy. Experimental results indicated that nanostructured solid solution alloy powders having homogeneous distribution of Ni and Cu were formed by milling-induced interdiffusion of the elements. Average crystallite size of the as-milled powders was decreased with increasing Ni content and milling duration, and found to be in the order of 15-40 nm after 30 h of milling for all powder compositions. Moreover, lattice parameter and lattice strain of solid solutions were increased with the time of MA, which was more intense for nickel-rich alloys

Page 1 from 1     

© 2022 All Rights Reserved | Iranian Journal of Materials Science and Engineering

Designed & Developed by : Yektaweb