Sharif Digital Repository

This research work deals with application of poly-saccharide to improve coating process of bioactive ceramic composite on aNd-Fe-B magnetic alloy substrate. Bioactive glass particles were synthesized through a sol-gel process and coated in the form of composite with poly-saccharide onto a magnetic substrate by electrophoretic deposition technique. Stable suspensions of 0.5 gr/lit polysaccharide polymer-ceramic were prepared using bioactive glass particles (<1µm), acetic acid 1%. The influence of added water to ethanol, pH and tri-ethanol-amine (TEA) additive on suspension stability, deposition rate and coating’s structure was investigated. It was shown that by increasing the water to ethanol... 

To obtain solutions containing Titanium, leaching of Ilmenite Concentrate of Kahnooj and its Slag by Sulfuric Acid 98% in various Conditions are Studied. Screening tests by Fractional Factorial method were designed, at this step effects of Temperature, Acid Concentration, Particle Size, Solid to liquid Ratio, Time and Stirring Speed were investigated and It was Concluded that Temperature, Time, Acid Concentration and Particle Size were the effective Parameters in both leaching process of Ilmenite and Slag. The Temperature, Time and Acid concentration had positive effect, whereas the Particle Size had negative effect. After screening step, effective parameters were optimized by Rotatable... 

This research tries to simulate the conditions of nanosized TiO2 powder production from pure commercial precursors, to produce nanosized TiO2 powder by leaching kahnouj ilmenite concentrate. For this purpose, the ilmenite concentrate was first oxidized to study the kinetics and optimization of oxidation process before leaching. Then the effect of pre-oxidation on the iron and titanium leaching efficiency was studied. Then the reductive leaching of concentrate using zinc and iron powders as reducing agent for Fe (III) to Fe (II) reaction was studied. The effect of reducing agent as well as oxidation and reduction on the leaching efficiency was studied. At the next step the optimum conditions... 

The most important raw material for production of titanium dioxide is titanium that used in Aerospace, Plastic, Pigment and Pharmacy industries. Due to the presence of titanium minerals in Iran, reduce imports of titanium dioxide is one of the goals of the Ministry of Industries and Mines to achieve self-sufficiency in the production of TiO2.One of the very rich sources of titanium is alluvial sands in northern of Iran. In this study the TiO2 high grade pigment production from these sources has been investigated. Titanium-bearing sands with 9.5% TiO2 are used to produce high grade TiO2 pigment. After magnetic separation stage and reach a purity of 16.2% TiO2, upgrading slag step is not... 

Titanium dioxide is one of the most important first material in many industrial applications and for producing Titanium.Although it was discovered more than 200 years ago and has been commercially processed for 85 years, it is still being actively investigated. So far Iran imports TiO2. But some projects have been planned to produce pure TiO2 from Ilmenite and Titanomagnetite ore. In the present work production of highly purity TiO2 from Ilmenite ore by chloride leaching has been investigated. Chloride leaching has been accomplished by several stages of leaching in hydrochloric acid, reduction, crystallization, hydrolysis and finally calcination of the powder. According to the result...