School of Mining and Metallurgical Engineering, National Technical University of Athens, Greece.
J Hazard Mater. 2011 Oct 30;194:42-7. doi: 10.1016/j.jhazmat.2011.07.072. Epub 2011 Aug 5.
The research work presented in this paper is focused on the development of a purification process of red mud sulphate leach liquor for the recovery of titanium oxide (TiO(2)) nano-powders in the form of anatase. Initially, titanium was extracted over iron and aluminium from the leach liquor by solvent extraction using Cyanex 272 in toluene, at pH: 0.3 and T: 25°C, with 40% extractant concentration. Stripping of the loaded, with titanium, organic phase was carried out by diluted HCl (3 mol/L) at ambient temperature. Finally, the recovery of titanium nano-powder, in the form of anatase, was performed by chemical precipitation at pH: 6 and T: 95°C, using 10 wt% MgO pulp as neutralizing agent. The produced precipitates were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric/differential thermal analysis (TGA/DTA). Their morphological characteristics and microstructure were studied by scanning electron microscopy (SEM). High grade titanium white precipitate, in the form of anatase, was obtained. Iron concentration in the precipitate did not exceed 0.3%, whereas no aluminium was detected.
本文的研究工作集中于开发一种从硫酸盐浸出液中回收钛白粉（TiO2）纳米粉末的赤泥净化工艺，该工艺以锐钛矿的形式存在。最初，通过在 pH 值为 0.3 和温度为 25°C 的条件下，使用 40%浓度的溶剂在甲苯中萃取，从浸出液中萃取铁和铝以提取钛。用稀释的 HCl（3mol/L）在环境温度下对负载有钛的有机相进行反萃。最后，通过在 pH 值为 6 和温度为 95°C 的条件下使用 10wt%MgO 浆作为中和剂进行化学沉淀，以锐钛矿的形式回收钛纳米粉末。采用 X 射线衍射分析（XRD）、傅里叶变换红外光谱（FT-IR）和热重/差热分析（TGA/DTA）对产物进行了表征。通过扫描电子显微镜（SEM）研究了其形态特征和微观结构。得到了高品位的锐钛矿型钛白粉沉淀。沉淀中铁的浓度不超过 0.3%，而未检测到铝。
