EXPANDED MINERAL GRANULES Russian patent published in 2023 - IPC C04B14/18 C04B20/06 

FIELD: production of expanded perlite granules.

SUBSTANCE: invention relates to a method for producing expanded perlite granules used as a filler for a bitumen product. A method for producing expanded perlite granules from a sand-like mineral material - perlite sand, containing a bound expanding substance - water, includes supplying perlite sand to the loading hole at one end of the furnace shaft, transporting it to the heat treatment area, heating to a critical temperature of at least 790°C in the heat treatment section, during which perlite sand acquires plasticity and begins to swell due to the intumescent agent - water, subsequent heating to a second temperature not higher than 1080°C, unloading expanded perlite granules at the other end of the furnace shaft. In this case, the second temperature is lower than the third temperature at which the surface of the expanded perlite granules cracks, and the second temperature is selected depending on the required density of the expanded perlite granules and so that part of the expanding substance remains in the expanded perlite granules in a bound state.

EFFECT: control of the swelling of sand-like mineral material with the production of expanded perlite granules with a closed-porous surface, increasing the compressive strength of the expanded granules.

6 cl, 2 tbl