Synthesis and casting of a lithium-bismuth compound for an ion-replacement electrorefiner.

摘要

The intermetallic compound Li(sub 3)Bi played an integral part in the demonstration of an ion replacement electrorefining method developed at Argonne National Laboratory. The Li(sub 3)Bi compound was generated in a tilt-pour casting furnace using high-purity lithium and bismuth metals as the initial charge. At first, small-scale ((approximately)20 g) experiments were conducted to determine the materials synthesis parameters. In the end, four larger-scale castings (500 g to 1250 g) were completed in a tantalum crucible. The metals were heated slowly to melt the charge, and the formation reaction proceeded vigorously above the melting point of bismuth ((approximately)270 C). For the large-scale melts, the furnace power was temporarily turned off at this point. After several minutes, the tantalum crucible stopped glowing, and the furnace power was turned on. The temperature was then increased to (approximately)1200 C to melt and homogenize the compound, and liquid Li(sub 3)Bi was cast into cold stainless steel molds. Approximately 3.7 kg of Li(sub 3)Bi was generated by this method.