Holmium (Ho): NdFeB Magnet Additive, Magneto-Optic Storage Material, Terfenol-D Alloy Component

Holmium is a silvery-white metal with element symbol Ho, soft enough to be cut with a knife. It melts at 1474°C, boils at 2695°C, and has a density of 8.795 g/cm³; exhibiting superconductivity near absolute zero. Holmium remains relatively stable in air but oxidizes readily at high temperatures when exposed to air or water, forming holmium oxide.

Applications

1. Used as additive in neodymium-iron-boron (NdFeB) permanent magnets
2. Applicable as magneto-optical storage material
3. Serves as one additive for preparing giant magnetostrictive terbium-dysprosium-iron alloys

Product Series

Health and Safety Information

Packaging Specifications

• Standard packaging: 50 kg/drum, 500 kg/pallet, ton bags
• Sample packaging: 500 g/bag, 1 kg/bottle

Production Method

After separating holmium from other rare earth elements via ion exchange or solvent extraction, metallic holmium can be prepared through metallothermic reduction. Unlike calcium reduction of rare earth chlorides, lithium reduction occurs in the vapor phase.

The lithium reduction reactor features two heating zones, combining reduction and distillation in one unit. Anhydrous holmium chloride is placed in the upper titanium crucible (also serving as HoCl₃ distillation chamber), while lithium metal reductant is loaded in the lower crucible. The stainless steel reaction vessel is evacuated to 7Pa before heating.

At 1000°C, maintained for a specific duration, HoCl₃ vapor fully reacts with lithium vapor. Reduced holmium metal particles deposit in the lower crucible. Post-reduction, only the lower crucible is heated to distill LiCl to the upper crucible. The complete reduction process typically requires about 10 hours.

For high-purity holmium :

• Use 99.97% ultra-pure lithium reductant
• Employ doubly distilled anhydrous HoCl₃