METHOD FOR PRODUCING PERLITE FROM POORLY EXPANDED RAW MATERIAL Russian patent published in 2023 - IPC C04B14/18 C04B20/06 

FIELD: construction.

SUBSTANCE: invention relates to a technology for the production of filler for building and heat-insulating materials, namely, expanded perlite with a fraction of 1.25-5 mm. The method for obtaining perlite from weakly expandable raw materials includes crushing the rocks of the Mukhor-Talinsky deposit, fractionation, preliminary heat treatment of raw materials and short-term firing in a vertical furnace. Rock is screened to fractions of 0.315-1.25 mm. Preliminary heat treatment of raw materials of these fractions is carried out in a drying drum at a temperature of 400-500°C to humidity 1-2%. The raw materials heated during the heat treatment from the drying drum are sequentially fed into a vertical furnace and short-term roasting is carried out at a furnace flame temperature of 1250-1260°C, whereas the raw materials are kept in the furnace for 3-4 s.

EFFECT: improving the quality of expanded perlite by improving strength characteristics and reducing open porosity.

2 cl, 1 tbl