A study on the extraction of gallium from gallium arsenide scrap

In the processing of the GaAs production, the final yield is often only less than 15% and the remainder of GaAs is wasted as scrap. It is, therefore, very important to recycle the gallium metal from GaAs scrap because this metal is a relatively rare element of importance in the high technology industry. The extraction of gallium from a GaAs scrap with various acids at different stirring speeds, temperatures, and concentrations of acids has been investigated. From these experiments, nitric acid was found to be the most effective extractant. More than 99% of gallium was leached with 2 N HNO3 at 60 degrees C in 2 h, and the extract:on of gallium was believed to be a self-catalytic reaction due to NO2 gas generated during the reaction. The apparent activation energy of this reaction was found to be about 39.9 kJ/mol. (C) 1998 Elsevier Science B.V. All rights reserved.