Tantalum Recovery Technique for Recycling of Tantalum Coated Composite Materials

In recent years, tantalum is being increasingly researched as a replacement for coatings for high-temperature applications. Tantalum is a refractory metal with low recycling rate of less than 1% because most tantalum secondary recovery techniques are primarily meant for recovery of other elements. In this study, the objective is to review various potential methods for recycling of tantalum coated steel composite, either at its end of life or for coating refurbishment purposes when coating is damaged. Tantalum can be recovered by both pyrometallurgical and hydrometallurgical methods, or a combination of the two, and it usually involves a whole process development with multiple steps for separation and purification from other elements. The main factor for selecting the best recovery method is dependent on the materials which are mechanically or chemically bonded with tantalum. This review summarizes various methods to recover tantalum from different secondary sources like tantalum capacitors, tantalum mill products, and tantalum in chemical processing industry. Lastly, we comment on the best method to recover tantalum from tantalum coated scrap.