机械力促进碳粉气化反应

Boudouard Reaction of Carbon Powder Promoted by Mechanical Force

研究了机械力对碳粉物理化学性能的影响规律。发现在球磨过程中,碳粉的颗粒度及晶粒不断细化、比表面积不断增大,当颗粒度小于40μm时,碳粉的晶粒大部分为100 nm左右的纳米晶粒。当作用时间较长时,碳粉会发生无定形化。在机械力的作用下,晶粒会产生畸变和位错,从而形成活化中心,降低反应活化能;同时由于碳粉比表面积的增大,增加了反应物与碳粉的接触面积,从而有利于加快气化反应的进行。与传统粉体(小于150μm)相比,细化后碳粉(小于40μm)的气化温度下降200℃左右。

The effect of mechanical impact on physical and chemical properties of carbon powders was studied. Dur ing milling, particle and grain sizes of carbon are gradually refined, and specific surface area is continuously increased. The grain sizes of carbon powders are around 100 nm while the particle sizes are 〈40 μm. Amorphism can occur when carbon powders are refined further. Distortion and dislocation occur during grain refining process, which form a lot of activation centers with decrease of activation energy of reactions. Gradual increase of specific surface area also improves reactivity of carbon powders. Reduction temperature of refined carbon powders （particle size 〈40μm） is about 200 ℃ less than that of coarse powder （particle size 〈150μm）.