Research On The Reduction Of Ilmenite By Microwave Plasma And Reduction Product

With the continuous development of Titanium, the increase demand ofTitanium source and exhaustion of natural rutile, ilmenite is graduallyreplace the natural rutile and becoming the largest source of Titanium in thisindustry. In the tradition industry of ilmenite, it is inevitable that someby-product and pollution, such as exhaust steam, effluent and offscum areproduced, and the comprehensive utilization efficiency is very low. For thisreason, it has realistic directive significance to design an new reductionprocess, and improve the efficiency of product by using ilmenite as rawmaterial. In this paper, ilmenite was reduced in the hydrogen and methaneatmosphere by using Microwave Plasma Chemical Vapor Deposition（MWCVD） technology. The photocatalytic capability and adsorption abilityof reduction product were studied.（1）Ilmenite was reduced by MWCVD, and the effect of differentfactor on the reduction rate，reduction product and its’ structure were studied.The results showed that powder, reduction time and gases affected thereduction products and its’ microstructure directly. The reduction process ofilmenite in plasma was analyzed, and the results showed that, the reductionprocess in hydrogen was controlled by chemical reaction, which is similar totradition carbothermic reduction. The reduction rate was improved and thekinetics mechanism was changed when reaction was taken placed inhydrogen plasma mixed with methane. When in hydrogen added with highflow of methane, the reduction process was in agreement with JanderEquation. Therefore, an new reaction model named "Fracture model" wasproposed to explain this phenomenon.（2）The photocatalytic capability of reduction product includingTiO₂-CNTs composite powder was studied. As the result of synergy of TiO2 and CNTs, the powder had better photocatalytic capability, compared withP25photochemical catalyst, even under visible light.（3）CNTs was modified by oxygen plasma in MWCVD, and its’adsorption ability for heavy metal ions of was studied in detail. The resultsshowed that some functional group were formed on the surface of CNTs bymodification.The adsorption ability of CNTs was increased, because thatthose functional group could attract cation and the anion in solution andform chemical absorption. The adsorption ability of CNTs could beimproved with the increase of the number of CNTs and functional group.