The present work aims to investigate the link between the oxidation and reduction of a weathered ilmenite concentrate in terms of phase transitions, microstructural changes, and element distribution. An ilmenite concentrate sample was pelletized and fired at 1000 °C in air, and as a result, the pellets were oxidized. The oxidized pellets were reduced by hydrogen gas at 1000 °C, which yielded almost complete metallization of the iron content of the pellets. The ore and the pellets were characterized in each step by XRD and SEM techniques, and distribution of elements and phases were investigated. Ilmenite, pseudorutile, and rutile were the main phases detected in the ilmenite concentrate sample, and depending on the weathering degree of the particles, different fractions of the phases were identified in their microstructure. It was found that irregular rutile grains dispersed in a pseudobrookite matrix is the morphology of the oxidized ilmenite phase. However, increasing microcracks and porosities were the only microstructural changes in the pseudorutile phase after oxidation in air. Studying the specific types of the ore particles and their oxidized and reduced forms indicated that the phase distribution in the ilmenite ore particles dictates the phase distribution in the oxidized and reduced ones. Results show that the morphology of the reduced particles includes a titanium (III) oxide matrix in which reduced iron globules are dispersed.

本工作旨在研究风化钛铁矿精矿的氧化与还原之间的相变，微观结构变化和元素分布之间的联系。将钛铁矿精矿样品制粒，然后在空气中于1000°C烧制，结果将其氧化。氧化的球团在1000°C的氢气中被还原，这几乎使球团中的铁含量完全金属化。通过XRD和SEM技术在每个步骤中对矿石和球团进行表征，并研究元素和相的分布。钛铁矿精矿样品中检测到的主要相是钛铁矿，假金红石和金红石，并且根据颗粒的风化程度，在其微观结构中鉴定出不同的相部分。已经发现，分散在假板钛矿基质中的不规则金红石晶粒是氧化钛铁矿相的形态。然而，增加的微裂纹和孔隙率是空气中氧化后假金红石相的唯一微观结构变化。对矿石颗粒的特定类型及其氧化和还原形式的研究表明，钛铁矿矿石颗粒中的相分布决定了氧化和还原矿石中的相分布。结果显示，还原颗粒的形态包括其中分散有还原铁球的钛（III）氧化物基质。在空气中氧化后，增加的微裂纹和孔隙率是假金红石相中唯一的微观结构变化。对矿石颗粒的特定类型及其氧化和还原形式的研究表明，钛铁矿矿石颗粒中的相分布决定了氧化和还原矿石中的相分布。结果显示，还原颗粒的形态包括其中分散有还原铁球的钛（III）氧化物基质。在空气中氧化后，增加的微裂纹和孔隙率是假金红石相中唯一的微观结构变化。对矿石颗粒的特定类型及其氧化和还原形式的研究表明，钛铁矿矿石颗粒中的相分布决定了氧化和还原矿石中的相分布。结果显示，还原颗粒的形态包括其中分散有还原铁球的钛（III）氧化物基质。