摘要 |
The process for purifying a contaminated chloro, bromo or iodo precursor salt of zirconium, hafnium or aluminum by means of providing a molten thermal body of one or more alkali or alkaline earth metal halides and the precursor salt containing impurities, maintaining the body at a temperature sufficient to volatilize the precursor salt away from its impurities while effecting a reducing condition in the body by means of a fluid, mobile reducing agent which is non-reducing of said precursor salt, and isolating the purified volatilized precursor salt from the body. The ultra purified isolated volatilized precursor salt can then be reacted with a fluorinating agent to produce the highly purified fluoride for use in optical fiber grade glass or the like.
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