Natural stone heat treatment is a processing of stone surface by heating to the top layer melting temperature. This kind of processing reaches two significant advantages at once – improving the aesthetic qualities of the stone and increasing the level of its resistance to the negative external influences such as water, mechanical effects, chemicals etc.
Natural stone heat treatment is a processing of stone surface by heating to the top layer melting temperature. This kind of processing reaches two significant advantages at once – improving the aesthetic qualities of the stone and increasing the level of its resistance to the negative external influences such as water, mechanical effects, chemicals etc.
Natural stone heat treatment is used for removing polished layer and giving a roughness to the surface. Heat treatment is also called burning or fire processing of natural stone. This kind of processing is carried out by a high-temperature exposure (1,300˚C – 2,700˚C) to the surface of the stone. It is principally applied to granite.
When heating to a high temperature minerals contained in granite are melting and scorching at the same time creating an irregular and rough surface. Gas equipment and a mixture of propane, butane and oxygen are used for a heat treatment.
Sometimes stones change their color in the result of a heat treatment; spots and stripes appear on slabs. It happens because of organic substances contained in stone; they react with alkali contained in improperly selected adhesive mixture. In order to avoid these problems they apply a special fast-acting grout being favorable to momentary binding water rising through the capillaries to the slab’s surface.
Previously heat treated granite is strictly prohibited to be re-burnt. During the second burning the surface is being strongly destroyed (peeled-off). While operating such granite will be gradually deteriorating.
Heat treated granite products are mainly applied to the external finishing of the houses, road paving, entrance lobby, platforms.
