Effect of acid leaching on helium and neon permeability of microspherical membranes based on cenospheres
Elena Rogovenko, Vladimir Yumashev, Elena Fomenko
Abstract
The microspherical membranes based on narrow fraction of cenospheres with high permeability to helium and high selectivity for He/Ne were recovered from cenosphere concentrate from Ekibastuz coal combustion. To increase the helium permeation microspherical membranes has been leached using 8.6 М HNO3. As a result, the developed microporous structure of cenosphere shell formed with predominant micropore size of 5, 6.4 and 13 Å, that led to an increase in helium permeation to 2 times. The obtained microspherical membranes exceed the synthetic glass hollow microspheres 3M K37 Glass Bubbles in helium permeation to 37-57 times, and the polymeric membrane material –(poly)sulphone in selectivity for He/Ne to 34-52 times.