Showing 6 results for محمدحسن عباسی
G. Aryanpour, M. H. Abbasi,
Volume 14, Issue 1 (1-1994)
Abstract
M. H. Abbasi and M. Safarnoorallah,
Volume 17, Issue 1 (7-1998)
Abstract
Fuel oil used in power plants contain metal impurities like Vanadium. After combustion, this metal remains in boiler fuel ash in the form of oxide. In this research, extraction of Vanadium oxide from fuel ash has been investigated. Two processes were used for this purpose. A pyro- hydrometallurgy and a hydrometallurgy process. In the pyro-hydrometallurgy process, using sodium carbonate, salt roasting of the ash followed by water leaching was carried out. Vanadium was then precipitated as ammonium vanadates which on heating decomposed and vanadium pentoxide (V2O5) was obtained. In the hydrometallurgy process, the ash was dissolved in sodium hydroxide. Vanadium oxide was then recovered from solution. Effects of various parameters in each case were investigated and the optimum condition for maximum recovery was determined.
M. Kasiri Asgarani, A. Saidi, M. H. Abbasi,
Volume 28, Issue 1 (Jun 2009)
Abstract
The effects of mechanochemical treatment of monoclinic zirconia in high energy planetary ball mill on its phase transformation were investigated. The mechanical treatment in ball mill reduces the grain size, increases microstrain, and causes phase transition to metastable nanostructured tetragonal and cubic phases. XRD and TEM results show considerable amounts of amorphous phase during ball milling. Surface area measurements by BET method over long milling times reveal that ZrO2 particles are agglomerated with an amorphous phase as a binder. The mechanical treatment increases the reactivity of zirconia in chlorine gas. Annealing of ball milled zirconia in the chlorine atmosphere produces oxygen vacancy in zirconia (ZrO2-x) and causes the amorphous phase to be crystallized and to change into cubic and tetragonal phases. The chlorine atmosphere increases the stability temperatures of cubic and tetragonal phases to 800°C and 1000°C, respectively. In this situation, the energy of grain boundary and oxygen vacancy play important roles in the stability of tetragonal and cubic phases.
Kh. Biralvand, M.h. Abbasi, A. Saidi,
Volume 31, Issue 1 (Jun 2012)
Abstract
Carbothermic reduction of Molybdenite in the presence of Magnesium oxide was thermodynamically studied. The stability diagrams for MoS2-MgO and MoS2-MgO-C Systems was prepared. The reduction of MoS2 with Carbon in the presence of Magnesium oxide proceeded through the direct oxidation of MoS2 by MgO to form intermediate molybdenum oxidized Species, MoO2 and MgMoO4. The results showed that the gaseous phase is mainly composed of CO. Stability diagrams for Mo-O-C (Reduction of MoO2 with carbon) and Mo-Mg-C-S-O (Reduction of MgMoO4 with carbon) were also investigated. The results showed that the Reduction of oxidized species leads to the formation of Mo, Mo2C, MoC or MgO products.
