Method for making glass silicate tiles

A method of making the glass-silicate tiles comprising:

• (a) creating of an initial blank by pouring an initial raw material containing glass granulate into a heat-proof mold and its consolidating;
• (b) gradual heating the blank in the heat-proof mold with holding periods between stages comprising following stages:
• a first stage of heating, predominantly from bottom of the blank with lower layer heating temperature higher than the temperature of upper layer to accelerate gas removal through the upper surface layer until a glass granulate sintering temperature is reached in the lower layer, a first holding period at these conditions to expel generated gases, heating the upper layer with higher speed than the lower layer until a Littleton temperature is reached in the lower layer and sintering temperature is reached in the upper layer and having a second holding period with these conditions, during the second holding period pressing the blank by a gas permeable press, after which additionally heating the blank until the upper layer reaches a temperature T.sub.4,5 corresponding to 4.5 Pa.s, under which the third holding period is realized until the lower layer reaches a temperature T.sub.5,5 on which a glass granulate viscosity logarithm is equal to 5.5 Pa.s;
• (c) after the third holding period the blank is cooled in the heat-proof mold with holding periods between following stages:
• a first stage of accelerated cooling is realized until the blank surface reaches a temperature T.sub.L, which is followed by a holding period for the period of time sufficient to achieve the Littleton temperature in the lower layer;
• after the first holding period a second cooling stage is performed until the annealing temperature is reached, after which a second holding period ensures a product annealing;
• after the first annealing a third cooling stage is realized until the surface reaches a temperature T.sub.13,5 on which the melt viscosity logarithm is equal to 13.5 Pa.s, after which the product is annealed, and, after the second annealing, cooled down to the room temperature.