MICROSPHERICAL GAS-PERMEABLE MEMBRANE AND METHOD FOR ITS PRODUCTION Russian patent published in 2012 - IPC B01D69/00 

FIELD: process engineering.

SUBSTANCE: invention relates to diffusion membranes and aims at producing selective membranes to be used in gas and oil industry, petrochemical industry, etc, to extract and concentrate target components, e.g. helium and oxygen from multicomponent gas mix. Microspherical gas-permeable membrane based on hollow silica-alumina microspheres is described; microsphere shell contains inclusions of mullite crystallites. Microspherical gas-permeable membrane is produced by extracting narrow morphologically homogeneous fractions of hollow non-perforated silica-alumina microspheres with Al₂O₃ content of 21-38 wt % and SiO₂ content of 55-67 wt %, with average thickness of the solid or porous shell of 2-3 μm and 5-10 μm, respectively, from concentrates of fly ash cenospheres resulted from coal combustion using steps of granulometric, magnetic, hydrostatic and aerodynamic separation. Narrow fractions of cenospheres are subjected to heat treatment at 980-1000°C for 2-3 h followed by hydrostatic separation of destructed globules.

EFFECT: higher helium gas permeability.

5 cl, 5 ex, 2 tbl, 9 dwg