In spite of the existence of several NiCd batteries treatment processes around the world, little is known about the fundamental aspects of this technology. The objective of this research is to study the most important technological variables of NiCd batteries recycling by vacuum distillation. Laboratory equipment was set up to study vacuum thermal processing of milled batteries. During the tests, the total pressure was maintained at 0.1 mbar while temperatures varied from 700 to 1100 degreesC. Results obtained show that the distillation process is possible at temperatures above 700 degreesC. If temperature is raised to the range of 900-1100 degreesC, treatment time is reduced to less than 2 h. At temperatures higher than 900 degreesC the recovery of Cd contained in the batteries reached 99.9%. (C) 2004 Elsevier B.V. All rights reserved.