高频氢等离子体增强还原制备超细铜粉

利用高频感应热氢等离子体强化还原制备超细铜粉，考察了加料速率、还原氢气流量、氢气分布位置、反应区空间、冷却温度等因素对铜粉颗粒性能的影响，对制备的铜粉颗粒进行氧含量、XRD晶体结构、松装密度、粒度分布和比表面积的表征。结果表明，优化的工艺条件为反应区内径100 mm，加料速率4 g/min，淬火气氩气气量500 L/h，氢气气量500 L/h并通入少量载气，由氢等离子电离产生的氢自由基可强化反应实现瞬时还原，不仅可控制铜粉形貌，还能有效控制铜粉颗粒大小；利用该方法制备出粒径分布100?200 nm、分散性好的超细球形铜粉颗粒。该方法操作简便、产品纯度高、气氛可控、对环境污染小。

Preparation of ultrafine copper powder by high frequency hydrogen plasma enhanced reduction

Ultrafine copper powder is widely used in the fields of electronics, lubrication, catalysts, due to its large specific surface area, excellent thermal conductivity and high surface activity. The ultrafine copper powder?s application performance is determined by the control technology of spherical, uniform particle size, monodisperse and high purity. The ultrafine copper powder was prepared by high frequency hydrogen plasma enhanced reduction with characteristics of simple operation, high purity, controllable atmosphere and less environmental pollution. The free radicals produced by hydrogen plasma arc was helpful to control the morphology and the particle size of copper powder. The feeding rate, reducing hydrogen flow rate, hydrogen distribution position, reaction zone space, cooling temperature, and the optimal process conditions were determined, and more uniform and well dispersed ultrafine spherical particles were prepared with particle size mainly between 100 and 200 nm. The oxygen content was under 1%, bulk density was 0.502 g/cm3.