METHOD FOR PRODUCTION OF FOAM GLASS Russian patent published in 2009 - IPC C03B19/08 C03C11/00 

FIELD: construction.

SUBSTANCE: to foaming charge that has the following chemical composition, wt %: SiO₂ - 70-75; Al₂O₃ - 4-7; CaO-6-7; MgO - 3-4; K₂O+Na₂O - 13-15; Fe₂O₃ - not more than 0.2, gasifier is added, at that ratio of gasifier : charge is equal to 0.3-1.0:100. Gasifier is technical carbon with high and/or medium index of dispersion, with ash content of not more than 0.45%, with mass fraction of total sulfur of not more than 1.1%, with number of dibutyl phthalate absorption of 97-105 cm³, iodine number of 39-47 g/kg. Glass crushing is done at the rate of 0.50-0.70 kg/s to specific surface of 850-900 m²/kg. Foaming is done by means of molds heating to the temperature of 840-880°C for 48-52 minutes with further isothermal delay for 21-23 minutes, at that temperature at molds bottom is more than in upper part of mold by 5-30°C. Stabilisation is carried out at the temperature of 590-610°C for 35-40 minutes. Annealing is done in annealing furnace from 550-600°C with the cooling rate of not more than 0.75-0.85 degree/min to 29-31°C, annealing duration is at least 14 hours.

EFFECT: low density of foam glass, low heat conductivity, increased strength and even closed cell structure.

2 ex, 1 tbl