Nevondo M, Koech L, Ola-Omole O O, Ramakokovhu M M, Teffo M L, Sadiku R
Institute for NanoEngineering Research, Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria, 0001, South Africa.
School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, Johannesburg, 2000, South Africa.
Heliyon. 2024 Mar 16;10(6):e28308. doi: 10.1016/j.heliyon.2024.e28308. eCollection 2024 Mar 30.
The depletion of the primary metal sources has prompted the exploration of alternative avenues for metal recovery. In the case of titanium and iron, the ferrovanadium residue produced through roast-leach processing of titanomagnetite presents a viable option for accessing these metals. Titanomagnetite resources, which contain valuable elements, such as iron, vanadium, and titanium, possess significant valuable potential. Titanomagnetite deposits are normally treated via smelting for vanadium or vanadium and iron recovery; titanium is not commercially recoverable. Titanomagnetites have recently been processed through the roast-leach method for vanadium primary production, and iron and titanium are typically part of the waste stream in this process. This study proposes a novel approach to determine the characteristic mineralogy and to study the phase transformation sequence of the roasted-leached ferrovanadium residue during the pre-oxidation process. Leaching was also done to evaluate the extraction potential of Fe, V and Ti on the pre-oxidized residue in comparison to the raw residue The roasted-leached ferrovanadium residue was sampled using the cone and quartering method and then, dried in an oven at temperatures of between 30 and 40 °C, for an hour after which, the remaining moisture content was determined. The bond milling method was employed to reduce the sample size, while the particle size distribution (PSD) was verified by using the standard laboratory Tyler series. Thereafter, the roasted-leached ferrovanadium residue was characterized with XRD, SEM, ICP-OES, and XRF. The samples were pre-oxidized at temperatures ranging from 300 °C to 1000 °C with an aim of improving the grades of iron, vanadium, and titanium-bearing minerals prior leaching. The results revealed the moisture content to be ∼5.07%. The bond work index of typical slags was estimated to be 10.2 kwh/t, with a determined d value of 200 μm. According to the XRF analysis, the predominant compounds present are hematite, FeO (75.55%), titanium dioxide, TiO₂ (12.79%), silicon dioxide, SiO (3.03%), and alumina, AℓO (2.62%), along with minor compounds. XRD patterns exhibited the presence of FeTiO and VO in the as-received samples, while pre-oxidation induced the evolution of new phases such as hematite, rutile, anatase, and pseudobrookite.
主要金属资源的枯竭促使人们探索金属回收的替代途径。就钛和铁而言，通过钛磁铁矿焙烧浸出工艺产生的钒铁残渣是获取这些金属的一个可行选择。含有铁、钒和钛等有价值元素的钛磁铁矿资源具有巨大的潜在价值。钛磁铁矿矿床通常通过冶炼来回收钒或钒和铁；钛在商业上无法回收。最近，钛磁铁矿通过焙烧浸出法进行钒的初级生产，在此过程中，铁和钛通常是废物流的一部分。本研究提出了一种新方法，用于确定焙烧浸出钒铁残渣在预氧化过程中的特征矿物学，并研究其相变顺序。还进行了浸出实验，以评估与原始残渣相比，预氧化残渣中铁、钒和钛的提取潜力。采用圆锥四分法对焙烧浸出钒铁残渣进行取样，然后在30至40°C的烘箱中干燥1小时，之后测定剩余水分含量。采用邦德磨矿法减小样品粒度，同时使用标准实验室泰勒筛网系列验证粒度分布（PSD）。此后，用X射线衍射（XRD）、扫描电子显微镜（SEM）、电感耦合等离子体发射光谱仪（ICP-OES）和X射线荧光光谱仪（XRF）对焙烧浸出钒铁残渣进行表征。为了提高浸出前含铁、钒和钛矿物的品位，对样品在300°C至1000°C的温度范围内进行预氧化。结果表明，水分含量约为5.07%。典型矿渣的邦德功指数估计为10.2 kwh/t，测定的d值为200μm。根据XRF分析，主要化合物为赤铁矿、FeO（75.55%）、二氧化钛、TiO₂（12.79%）、二氧化硅、SiO（3.03%）和氧化铝、AlO（2.62%）以及少量化合物。XRD图谱显示，原样中存在FeTiO和VO，而预氧化诱导了赤铁矿、金红石、锐钛矿和假板钛矿等新相的形成。
