METHOD OF PRODUCING EXPANDED PEARLITE-BASED MICROSPHERICAL FILLER Russian patent published in 2014 - IPC C04B20/06 

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic finely dispersed materials and specifically to hollow glass-lined microspheres based on expanded pearlite. In the method of producing expanded pearlite-based microspherical filler, which includes dry grinding starting material, heat treatment thereof and subsequent expansion, heat treatment of the starting material is carried out before grinding, and 2-3 wt % of a suspension of a carbon-containing liquid and a glass-forming additive, ground to particle size smaller than 2 mcm, are further added to the mixture during grinding, wherein content of said glass-forming additive is 0.2-0.5% of the weight of pearlite. For more uniform deposition of the carbon-containing liquid and the glass-forming additive on the surface of the pearlite microparticles, a surfactant selected from a group of cationic surfactants can be added to the suspension. To further reduce water absorption after expansion, the microspheres can further be treated with a water repellent.

EFFECT: obtaining a high-strength and hydrophobisated microspherical filler.

3 cl, 1 tbl