Method for Recycling Tantalum from Waste Tantalum Capacitors by Chloride Metallurgy

Abstract

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.

Recovery of Tantalum and Manganese from Epoxy-Coated Solid Electrolyte Tantalum Capacitors through Selective Leaching and Chlorination Processes

“…The recovery of tantalum reaches 94% and the purity of TaCl 5 is about 99%. Comparing to previous studies [15,17,[30][31][32], the results in this study achieved equivalent recovery of Ta in the chlorination process but lower than the hydrometallurgy. Therefore, the detailed reaction mechanism and optimal chlorination process will be discussed in future work.…”

“…To overcome these shortcomings, ionic liquids are studied in hydrometallurgy [24,28,29]. In the chlorination process, chlorine gas or hydrogen applied to tantalum and niobium raw ore [6] or ferrous chloride applied to tantalum capacitors [15,[30][31][32] have both been studied.…”

Ordered clustering method and degradation trend analysis for performance degradation of tantalum capacitor

“…where m = 1, 2, · · ·, 18; n = 1, 2, · · ·, 16. In order to simplify the calculation, the degradation data are standardized using (3).…”

“…The tantalum capacitor is widely used in many fields, such as military, aerospace, and medical fields [1][2][3]. The performance of the tantalum capacitor directly influences the safe running of the system.…”

Dismantling of Printed Circuit Boards Enabling Electronic Components Sorting and Their Subsequent Treatment Open Improved Elemental Sustainability Opportunities

“…To reach higher grades, one needs to include either: (i) a fairly classical halogenation purification step [139,140], with some possible innovation to avoid the toxicity of halide gases [141], for example by using CCl 4 [139], or FeCl 2 as a chlorination agent [142,143]; or (ii) additional hydrometallurgy and reduction steps. For the latter case, most published works proposed alternative approaches that avoid the use of hydrofluoric acid for the Ta lixiviation step [144].…”