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本文借助差热热重分析的方法研究了纯组分四方晶型 WO_(2.90)蓝色氧化钨氢还原动力学,并在此基础上探讨了利用新型钨酸盐 ART 热分解制备纯组分蓝钨并进一步氢还原制备超细钨粉的新工艺.研究结果表明,WO_(2.90)蓝钨高温氢还原经历两个阶段,分别受扩散控制及化学反应控制,表观活化能分别为13.9kJ/mol及65.8kJ/mol,还原温度、氢气流量及装料量都对反应速度有明显影响.在动力学研究基础上,提出以纯组分 WO_(2.90)蓝钨为原料氢还原制备平均粒径小于1μm的超细钨粉的工艺条件:温度700-850℃,还原时间3小时以上,氢气流量3m~3/h,露点-40℃以下,蓝钨料层厚度30mm 以下.本文研究结果对认识蓝钨还原过程及确定新工艺制取超细钨粉的工艺条件具有指导意义.
In this paper, the thermodynamic and thermogravimetric analysis of pure tetragonal WO_ (2.90) blue tungsten oxide hydrogen reduction kinetics, and on this basis, the use of new tungstate ART thermal decomposition of pure component blue Tungsten and further hydrogen reduction to prepare ultrafine tungsten powder.The results show that the hydrogen reduction of WO_ (2.90) blue tungsten at high temperature goes through two stages, controlled by diffusion control and chemical reaction respectively, and the apparent activation energies are 13.9kJ / mol and 65.8kJ / mol respectively, and the reduction temperature, the flow rate of hydrogen and the amount of charge all have a significant effect on the reaction rate.On the basis of kinetic studies, it is proposed that the average particle size less than 1μm ultrafine tungsten powder process conditions: temperature 700-850 ℃, reduction time of more than 3 hours, the hydrogen flow rate of 3m ~ 3 / h, dew point below -40 ℃, blue tungsten layer thickness of 30mm or less.The results of this study recognize Blue Tungsten reduction process and to determine the new process for the preparation of ultrafine tungsten powder process conditions have guiding significance.