Method for treating rare earth-transition metal scrap

Patent · 31 December 1991

OSTI ID:868613

Schmidt, Frederick A ^[1]; Peterson, David T ^[1]; Wheelock, John T ^[2]; Jones, Lawrence L ^[3]

---

1. Ames, IA
2. Nevada, IA
3. Des Moines, IA

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy.

• Research Organization: Ames Laboratory (AMES), Ames, IA; Iowa State University, Ames, IA (US)
• DOE Contract Number: W-7405-ENG-82
• Assignee: Iowa State University Research Foundation, Inc. (Ames, IA)
• Patent Number(s): US 5174811
• Application Number: 07/591,040
• OSTI ID: 868613
• Country of Publication: United States
• Language: English

Related Subjects

/75/
acceptable
alloy
articles
cacl
caf
concentrations
earth
earth-iron
earth-iron alloy
earth-transition
earth-transition metal
electroslag
end-use
etc
fabrication
fluoride-bearing
flux
impurities
inductoslag
iron
iron alloy
magnets
manufacture
melted
metal
metal scrap
metallic
metallic impurities
method
mixtures
na
nd-fe-b
nd-fe-b scrap
nitrogen
non-metallic
operations
oxygen
permanent
permanent magnet
permanent magnets
picked
practice
prefused
previous
process
rare
rare earth
rare earth-iron
rare earth-transition
reduce
reduced
reduction
reduction process
remelted
resulting
reuse
scrap
slag
thermite
thermite reduction
tramp
tramp impurities
transition metal
treated
treating
treating rare