固定床气体氟化反应器结构对氟化钆中氧的影响

Effects of Structure of Fixed- bed Fluorination Reactor on Oxygen in Gadolinium Fluoride

以氧化钆为原料,氟化氢为氟化剂,在固定床气体氟化反应器(48 cm×110 cm)内,采用控制变量法研究了反应器径向、轴向、气流配送方式、氧化钆布料方式对氟化钆中氧含量的影响,并对影响氧含量的物理化学因素进行了分析。结果表明,270℃时,反应器半径由0 mm增加到160 mm时,氟化钆中的氧含量由4.62%减小到1.10%,200 mm时,反而增加到1.60%;540℃时,反应器半径由0 mm增加到200 mm时,氟化钆中的氧含量由0.02%增加到0.80%;氧含量随轴向距离的增加略有增大。按第III方式配送气流,氟化氢利用率高,反应器内氟化钆中的氧无偏析、含量较低。采用中间厚四周薄的布料方式氟化钆中的氧均一、稳定。物理化学分析表明,提高氟化过程温度、增加氟化氢气体浓度、减少反应器壁面料层厚度、改善气流配送方式等均可有效降低氟化钆中的氧含量。

GdF_3was synthesized using Gd2O3as raw material and HF as fluridizer in the fixed- bed gas fluorination reactor. Effects of radial dimensions of reactor,axial dimensions of reactor,distribution mode of HF and feeding mode on oxygen content in GdF3were investigated by the variable- controlling method. And physical- chemical factors of influencing oxygen content were analyzed. Oxygen content in GdF3from 4. 62% reduced to 1. 10% when reactor radius from 0 increased to 160mm at 270 ℃. Oxygen content was 1. 60% when radius was 200 mm at 270 ℃. Oxygen content in GdF3from 0. 02% increased to 0. 08% when reactor radius from 0 increased to 160mm at 540 ℃. Oxygen content increased slightly with the increase of axial distance. High utilization rate of HF and low and uniform oxygen content were obtained when using the third distribution of HF. Oxygen content in GdF3is stable when material thickness near the edges is smaller than that at center region.