Method for treating rare earth-transition metal scrap

Patent · Wed Jan 01 00:00:00 EST 1992

OSTI ID:868613

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

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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 Univ., Ames, IA (United States)
• 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

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