Method for Recycling Tantalum from Waste Tantalum Capacitors by Chloride Metallurgy

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• 作者：Bo Niu ; Zhenyang Chen ; Zhenming Xu
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2017
• 出版时间：February 6, 2017
• 年：2017
• 卷：5
• 期：2
• 页码：1376-1381
• 全文大小：425K
• ISSN：2168-0485

文摘

The demand for tantalum (Ta) is rapidly increasing due to the manufacture of Ta capacitors (TCs) for electronic devices. With the increasing awareness of environmental protection and conservation of rare metal Ta, recycling of Ta from waste TCs (WTCs) is becoming a hot topic in current society. In this study, an efficient and environmentally friendly process for recycling Ta from WTCs by chloride metallurgy (CM) is proposed. In the CM process, the nontoxic FeCl₂ is chosen as the chlorination agent. Thermodynamic analysis demonstrates that Ta can selectively react with FeCl₂, and the generated TaCl₅ can be easily separated and then condensed in the condensation zone. The recovery of Ta can reach 93.56% under the optimal chlorination parameters as follows: heating temperature of 500 °C, FeCl₂ addition amount of 50%, holding time for 2 h, and particle size of Ta-rich powder less than 0.24 mm. Moreover, the kinetic mechanism is discussed, and the rate-controlling step in the chlorination reaction of Ta is determined by mixed control. No hazardous gas and liquid waste is produced during the whole process. Therefore, this study presents an environmentally friendly and promising method for the cyclic regeneration of rare metal Ta from WTCs.