Bauer-DJ; Fischer-DD; Lindstrom-RE
U S Pat 3 862 292 1975 Jan; :
Rhenium is recovered from dusts and fumes collected in molybdenite roasting by leaching and adsorption with activated carbon. Further recovery from the carbon is accomplished by elution with a water- soluble alcohol or a water-alcohol mixture, if molybdate is first eluted with brine. The c is later regenerated for reuse by washing with water. A suitable brine for removing mo consists of 150-350 g nacl or nacl+na2so4/l. To elute the re the alcohol can contain up to 50 pct water. The eluate can be boiled down to crystallize the perrhenate, or the latter can be extracted with a Tertiary amine, stripped with nh4oh, and the ammonium perrhenate reduced by h2 to re. When re was adsorbed in a column of activated carbon from an aqueous solution at ph 8.5 Containing 1 g re/l and 10 g mo/l, and the mo was washed out completely with 25 pct nacl solution, the c was contacted with 4 bed volumes of methyl alcohol containing 25 pct h2o to recover 97 pct of the re in the solution. The c was washed with water and used for 20 more cycles.
U.S. Pat. 3,862,292; Jan. 21, 1975; Chem. Abstr. 82:127,114P, 81:94,464B