Abstract: Artificial pumice is produced which comprises cellular glass bodies devoid of glass crust and with rounded edges and points, and preferably having a density between about 0.2-2.0 grams per cubic centimeter and preferably having maximum size of between about 1-30 centimeters. These glass particles are relatively lightweight and are abrasive, which regular and regulatable density, mechanical strength, cell size, and an abrasivity. Particles of waste glass (e.g. of a size up to about 1 millimeter) or vitrifiable material, are mixed with a cellulating agent such as calcium carbonate. The mixture is heated, as by disposing it on an endless refractory belt which continuously passes through a kiln at a temperature of about 700.degree. C. or greater, to melt the particles, and to produce relatively small or large cellular glass bodies. The size of the large cellular glass bodies can be reduced to small bodies by sudden temperature change (e.g. quick cooling at a rate of between about 100.degree.-400.degree. C.

Abstract: A continuous cellular glass manufacturing method is described. A mixture of ground glass and of one or more substances, such as coal dust, coke dust, graphite dust, one or more powdery and/or liquid and/or diluted hydrocarbons, one or more powdery and/or liquid and/or diluted carbohydrates, one or more hydrocarbons and/or their derivatives, one or more powdery and/or diluted carbonates, fine natural earth, ground natural stones, ground ceramics, cement, one or more powdery and/or dissolved soluble glass substances, water and other similar substances, is partly or totally solidified by drying and/or by reaction, letting it stand for at least 10 minutes. The mixture thus solidified is granulated and the glassy mass so obtained is distributed over a refractory wire conveyor belt or of refractory sheet, after spreading a separating substance in the conveyor belt which prevents the glassy mass from sticking to the conveyor belt.