1994 Volume 110 Issue 15 Pages 1197-1202
Interactions among the species in the NdF3-Ca-CaCl2-Fe mixture have been primarily investigated by employment of a simple thermoanalytical technique. Effects of temperature and time on the small scale preparation of Nd-Fe alloys from the mixture have been tested in a temperature range of 760-1, 070°C. It was discovered that the molten salt containing Nd ions was already established even at a low temperature as 710°C by mutual dissolution of solid NdF3 and CaCl2, hence the reduction was achievable fast even at below the melting point of metallic Ca. More than 90% of the NdF3 was reduced within two minutes as soon as the melting of CaCl2 (around 760°C). The reason why were not obtainable high alloy recoveries prior to the melting of metallic Ca was that the solid Ca hindered Nd-Fe alloy granules to settle down to the alloy pool formed on the bottom of the crucible. In order to obtain the maximum recovery within short time, it is important to heat the charge mix to the melting point of Ca as rapid as possible. High alloy recoveries over 9% were achieved within five minutes after complete melting of Ca (around 850°C)