Production of Tantalum Powder by Magnesiothermic Reduction of Feed Preform

抄録

To develop an effective process for tantalum powder production, a new preform reduction process (PRP) based on the magnesiothermic reduction of feed preform containing tantalum oxide (Ta₂O₅) was investigated. The feed preform was fabricated from slurry, which was made by mixing Ta₂O₅ powder, flux (e.g., CaCl₂), and binder. Various compositions of preform in the form of plates were prepared using a conventional casting technique, and the fabricated preform was heated at 1273 K before reduction in order to remove the binder and water. The sintered solid preform, containing Ta₂O₅, was then placed in a stainless steel container, and reacted with magnesium vapor at a constant temperature ranging between 973 and 1273 K for 6 hours. Pure tantalum powder was recovered from the reduced preform after leaching it in acid. This process was found to be suitable for producing a fine homogeneous powder, when the composition of flux and reduction conditions are controlled.