2004 Volume 68 Issue 12 Pages 1031-1038
In the conventional metallothermic reduction (MR) process for obtaining tantalum powder in batch-type operation, it is difficult to control morphology and location of tantalum deposits. On the other hand, an electronically mediated reaction (EMR) process is capable to overcome these difficulties and has a merit of continuous process, but it has the defect that the reduction yield is poor. MR-EMR combination process is a method that is able to overcome demerits of MR and EMR process. In this study, an MR-EMR combination process has been applied to the production of tantalum powder by sodium reduction of K2TaF7. In the MR-EMR combination process, the total charge passed through external circuit and average particle size (FSSS) were increased with increasing reduction temperature. The proportion of fine particle (-325 mesh) was decreased with increasing reduction temperature. The tantalum yield was improved from 65 to 74% with increasing reduction temperature. Considering the charge, impurities, morphology, particle size and yield, an reduction temperature of 1123 K was found to be optimum temperature for MR-EMR combination process.
