镁热还原Ta_(2)O_(5)制备电容器用钽粉工艺研究

Technical Study on Preparation of Tantalum Powder for Capacitors by Magnesium Thermal Reduction of Ta_(2)O_(5)

通过镁热还原Ta_(2)O_(5)制备电容器用钽粉,研究了镁加入量、保温温度及时间对钽粉成分及其电性能的影响。结果表明:镁加入量过少、保温温度过低以及保温时间过短均会造成Ta_(2)O_(5)还原不彻底;但镁加入量过多会造成钽粉漏电流增大以及镁屑和酸的浪费,保温温度过高、保温时间过长则会造成钽粉电容损失及能耗增大,成本增加。为了达到降本增效的目的,镁加入量宜为理论量的2倍,保温温度宜控制在960℃左右,保温时间以6 h为宜。此工艺条件下制备的钽粉氧含量为0.362 0%,镁含量为0.001 1%,漏电流系数K值为4.4×10^(-4)μA/(μF·V),重量比容为15 630μF·V/g。

Tantalum powder for capacitors was prepared by the magnesium thermal reductionof Ta_(2)O_(5).The effects of magnesium addition,holding temperature,and holding time on the composition and electrical properties of the tantalum powder were investigated.The results show that insufficient magnesium addition,low holding temperature,and short holding time result in incomplete reduction of Ta_(2)O_(5).However,excessive magnesium addition leads to an increase in the leakage current of tantalum powder and the waste of magnesium chips and acid.And high holding temperature and long holding time lead to a decrease in the electric capacity of tantalum powder and an increase in energy consumption,thereby raising the cost.To reduce costs and improve efficiency,the optimal process conditions include the magnesium addition of twice the theoretical amount,holding temperature of around 960 ℃,and holding time of 6 hours.Under such conditions,the prepared tantalum powder exhibits an oxygen content of 0.362 0%,magnesium content of 0.001 1%,leakage current coefficient(K value) of 4.4×10^(-4) μA/(μF·V),and weight-specific capacity of 15 630 μF·V/g.