  The AMoRE collaboration searches for the neutrinoless double-beta decay of
100Mo with ultra-radiopure molybdate crystals operated as low-temperature
scintillating bolometers. For such a rare event search experiment, the
techniques for investigating and reducing radioactive background contaminants
in detector materials are extremely crucial. This paper discusses techniques
for deep purification of enriched molybdenum for growing the crystals and the
recovery of 100MoO3 from the residual melt left after growing lithium molybdate
crystals. The purities of enriched molybdenum trioxide powders before and after
the purification and that of the recovered powder were tested with ICP-MS;
results of these tests are presented.
