微波作用下温度对白云鄂博稀土铁矿固氟效率的影响

针对白云鄂博稀土铁矿在“选冶”过程中的固氟问题,以白云鄂博稀土铁矿为原料,通过XRD、化学检测、单因素实验以及红外光谱拟合分析法,研究了在微波作用下碳酸氢钠在不同温度下的固氟效果。实验结果表明最佳固氟温度条件为： 973.1K,在碳酸氢钠占比40%、焙烧恒温时间60min时可获得固氟率最高为83.49%;利用傅里叶红外光谱以及二阶导光谱法定量分析焙烧固氟矿物,结果表明：随焙烧温度的升高,氟化钠的吸收峰峰峰面积呈现递增趋势,温度873.1K、973.1 K分别与773.1 K相比增加了109.27%、120.16%,在973.1K焙烧温度下的氟化物含量较多且有稳定的红外吸收峰;同时,加入钠剂的固氟宏观反应过程符合Avrami-Erofeev动力学模型,属于随机成核及随后生长的化学反应控制,表观活化能为58.19 KJ/mol。该实验结论,对于开发白云鄂博稀土铁矿绿色回收工艺,具有参考研究价值。

,(R2=0.995) (4)

Aiming at the fluorine fixation problem of Bayan Obo rare earth iron ore in the process of "dressing and smelting", using Bayan Obo rare earth iron ore as raw material, the fluorine fixation effect of sodium bicarbonate under microwave effect was studied by XRD, chemical detection, single factor experiment and infrared spectrum fitting analysis method.The experimental results show that the optimal fluorine fixation temperature is 973.1K, the highest fluorine fixation rate is 83.49% when the ratio of sodium bicarbonate is 40% and the calcination time is 60min.Fourier infrared spectroscopy and second conductance spectroscopy were used to quantitatively analyze calcined fluorosolid minerals. The results show that:With the increase of calcination temperature, the absorption peak area of sodium fluoride showed an increasing trend. The temperature of 873.1K and 973.1K increased by 109.27% and 120.16%, respectively, compared with that of 873.1K. At 973.1K, fluoride content was more and there was a stable infrared absorption peak.In addition, the macroscopic reaction of solid and fluorine was in accordance with the Avrami-Erofeev kinetic model , which was controlled by random nucleation and subsequent growth, and the apparent activation energy was 58.19 kJ /mol.The experimental conclusion is of reference and research value for the development of green recovery technology of Bayan Obo rare earth iron ore.