淅川钒矿钠化焙烧过程中热学性能、物相变化及钒氧化态变化的研究

STUDIES ON THE THERMOCHEMICAL BEHAVIOURS OF XICHUAN VANADIUM ORE IN THE ROASTING PROCESS

本文通过差热热重和X射线衍射分析等方面研究了淅川钒矿在钠化焙烧过程中的热学性能、物相变化及钒氧化态的变化.结果表明,在钒矿钠化焙烧过程中,NaCl于753K左右开始分解,钠化反应始于923K,最佳反应温度为1123K.当焙烧温度在673-973K之间时,钒氧化迅速,973K以后钒氧化比较缓慢,V(Ⅴ)含量在1123K时达到最高.结果还表明,NaCl能加速钒的氧化,提高V(Ⅴ)的转化率.

Thermochemical behaviours of Xichuan vanadium ore during the roasting process were studied by TG-DTA-DTG and XRD methods. The results show that the decomposition of NaCl occurs at 753K and the reaction between vanadium ore and NaCl begins at 823K. The optimal reaction temperature is 1123K as the leaching rate of Ⅴ is concerned. The oxidation of Ⅴ(Ⅳ) is more rapid at 673-973K than above 973K, and the content of Ⅴ(Ⅴ) reaches the maximum at 1123K. It is found that oxidation of Ⅴ can be accelerated by addition of NaCl, resulting in higher conversion of Ⅴ(Ⅳ) to Ⅴ(Ⅴ).