8. Metal purification and fabrication
Purification is carried out on ammonium perrhenate, NH 4 ReO 4 , obtained by ammonia neutralization of a solution containing perrhenic acid. Since the solubility of perrhenate varies widely with temperature (29 g/L at 0 ˚C, 173 g/L at 50 ˚C and 250 g/L at 100 ˚C), fractional crystallizations are carried out in four or five stages, with the aid of which a 99.5% pure salt is obtained.
The metal is obtained by hydrogen reduction of ammonium perrhenate:
Exclusive to subscribers. 97% yet to be discovered!
Already subscribed? Log in!
Metal purification and fabrication
Pollution and the environment
Article included in this offer
"Metal manufacturing processes and recycling"
(
116 articles
)
Updated and enriched with articles validated by our scientific committees
A set of exclusive tools to complement the resources
References
Exclusive to subscribers. 97% yet to be discovered!
Already subscribed? Log in!
