Different Drying Methods On The Properties Of Ultrafine Copper Powder

The super fine copper powder has been widely used in many fields and a broad prospect of application due to its special physical and chemical properties of superior conductivity and thermal conductivity, big specific surface area etc. And the preparation of high quality super fine copper powder has became the topic now. Drying is a key working procedure of the super fine copper powder processing. The traditional dry method of the super fine copper powder (hot drying) is oxidation easily, time consuming, work much and difficult to cope with market demand. So the high efficiency, low cost and stable quality of new drying technology is needed. The microwave drying technology can be used to improve its copper powder dry speed and energy saving. The vacuum freeze-drying technology can also effectively prevent oxidation of copper powder, etc.The performance of the copper powder which is influenced by various of dry ways is discussed in this paper. The best dry way of super fine copper powder is found, when the good performance of super fine copper powder, the conservation of energy and the protection of environment are ensured. The methods and work level of the super fine copper powder will be improved and optimized by the research results. A certain theoretical basis will be provided for the control and the continuous production of high quality super fine copper powder. The economic benefits can also be increased.The performance of fluid loss rate, particle size and distribution, loose put density, specific surface area, surface morphology and electrical conductivity of ultrafine copper powder, which was influenced by the hot air, microwave, cold, hot air-microwave and vacuum drying technology, was discussed at different temperature in this subject. The best dry way of the super fine copper powder was found out by comparing the different drying technology which influenced the performance of the copper powder. The results show that:(1) It shows that the water loss rate of the super fine copper powder which used by microwave drying method is maximum(63.58). Some agglomerate is produced for the high local temperature of copper powder which used by microwave drying method, and the particle size increases. But after the hot air treatment, its surface changed obviously, and had smoother distribution. The ice in copper powder directly convert into gas by using the freeze-drying method, and the particles together between copper powders is effectively blocked. The average particle size of the copper powder is minimum, as0.58μm. And the compact resistance is0.0614Ω. It ensures the quality of the copper powder.So the freezing drying method is a good choice of drying copper powder.(2) By comparing different drying methods, we found, the fixed investment of hot air drying is the minimum, but the ability of the material performance protection is much weaker. The energy efficiency in microwave drying is the best, but the material drying effect in microwave drying method is bad; the fixed investment of freezing drying method fixed is the most, but the quality of the copper powder is the best; The energy efficiency in vacuum drying method is well, and fixed investment is smaller, the quality of the copper powder is better.