Search published articles


Showing 2 results for Sh. Shahriari

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

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.
Sh. Shahriari, M. Ehteshamzadeh,
Volume 10, Issue 1 (march 2013)
Abstract

Abstract: Plasma electrolytic oxidation (PEO) technique was used to prepare ceramic coatings on the casted aluminum alloys containing ~5 and ~9.5 wt.% Mg. The applied voltage was controlled at 450V and 550V for evaluating the effect of this main parameter, as well as, magnesium content of the substrate on the microstructure and electrochemical corrosion behavior after PEO treating. The results of X-ray diffraction confirmed formation of galumina and MgSiO3. It was found that higher applied voltage caused fewer and minor discharge channels which led to higher corrosion resistance. Also, increasing of magnesium content of the substrate caused decreasing of polarization resistance, which could be associated to the formation of MgSiO3.

Page 1 from 1     

© 2019 All Rights Reserved | Iranian Journal of Materials Science and Engineering

Designed & Developed by : Yektaweb