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Article: Extraction and mutual separation of rare earths from used polishes by chemical vapor transport
- Article from:
- Metallurgical and Materials Transactions
- Article date:
- February 1, 1999
- Author:
CopyrightCopyright Minerals, Metals & Materials Society and ASM International Feb 1999. Provided by ProQuest LLC. (Hide copyright information)
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A dry recovery process for rare earths from used polishes has been investigated by using a chemical vapor transport method via the formation of vapor complexes RAl^sub n^Cl^sub 3+3n^ (R = rare earth). The used polishes were chlorinated with N^sub 2^ + Cl^sub 2^ gas mixture at 1273 K, and the resulting rare earth chlorides were transported chemically with the vapor complexes along the temperature gradient. Most rare earth chlorides, AICI^sub 3^, and FeC1^sub 3^ were transported during 82 hours of heating. The rare earth chlorides were mainly condensed over the temperature range of 1220 to 730 K. On the other hand, AICl^sub 3^ and FeCl^sub 3^ were deposited at temperatures below 400 K. The ...