Carbothermic reduction of llmenite (FeTiO3) and rutile (TiO2)
Carbothermic reduction of llmenite (FeTiO3) and rutile (TiO2)
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DOI：
10.1007/s11663-999-0113-7
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发表时间：
1999-12
期刊：
影响因子：
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通讯作者：
N. Welham;James S. Williams
中科院分区：
文献类型：
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作者：
N. Welham;James S. Williams
通过稳态和动态热技术与 X 射线衍射相结合，研究了钛铁矿的机械活化碳热还原机制。发现反应首先快速还原为元素铁和金红石，然后金红石缓慢还原为通式 TinO2n−1 的一系列氧化物，直到形成相对稳定的 Ti3O5。铁可能仅以>3的形式结合到TinO2n−1晶格中，形成成分不确定的混合氧化物。 TiC 的形成在低至 1100 °C 的温度下很明显，但反应速率极慢，可能是由于固态扩散限制。升高温度会增加 TiO2 向 TiC 的转化率，直到它成为唯一确认的产物。通过检查纯金红石的还原，消除了铁对还原后期的影响。结果发现，铁的存在增强了 Ti3O5 的还原。事实证明，铁从钛产品中的分离度很高，在初始还原后去除了 > 90% 的铁。当产品为元素铁和碳化钛时，除铁率缓慢增加至近 100%。
The mechanically activated carbothermic reduction mechanism of ilmenite has been examined by a combination of steady-state and dynamic thermal techniques coupled with X-ray diffraction. The reaction was found to proceedviaan initial, rapid reduction to elemental iron and rutile, which was followed by a slow reduction of rutile to a series of oxides of the general formula TinO2n−1until Ti3O5was formed, which was found to be relatively stable. Iron was probably incorporated into the TinO2n−1lattice only forn>3, forming mixed oxides of uncertain composition. The formation of TiC was evident at temperatures as low as 1100 °C, but the rate of reaction was extremely slow, presumably due to a solid-state diffusion limitation. Increasing the temperature gave increasing conversion of TiO2to TiC until it was the only confirmed product. The effect of iron on the later stages of reduction was removed by examining the reduction of pure rutile. It was found that the reduction of Ti3O5was enhanced by the presence of iron. The separation of iron from the titanium product proved to be high, with > 90 pct of iron removed after the initial reduction. The iron removal increased slowly to almost 100 pct when elemental iron and titanium carbide were the products.