Samarium-cobalt alloys are used as materials for powerful magnets with relatively high Curie temperatures. Samarium
is one of the rare earth elements and is a valuable and expensive element. Recovery, reuse, and recycling of rare earth elements are
necessary to protect this rare earth resource. Recently, a new two-step precipitation method to recover samarium phosphate from
transition metal mixtures has been reported. Since rare earth phosphates are the main component of rare earth ores, a new method
has been proposed to recover rare earth elements as phosphates. In this study, we attempted to obtain samarium phosphate by this
two-step precipitation method by dissolving the actual magnet used. This method can separate and recover samarium phosphate
from mixed metal ion aqueous solutions without the use of high temperatures or special equipment. In this study, nitric acid,
hydrochloric acid, and sulfuric acid were examined as acids that dissolve the magnet. The dissolution of magnets with acid in
amounts equal to, double, and triple the chemical equivalent was investigated.
Key words: rare earth recovery; phosphoric acid; precipitation
|
