Stone wool is a sub-type of mineral wool produced from molten igneous rocks (gabbro and basalt). Applications of stone wool include sound and thermal insulation of buildings. Stone wool is a natural material with a content of stone at about 95%.
It is non-flammable material that can withstand temperatures up to 1000 ° C. Moreover, it hampers the fire progress. Due to open porosity, stone wool products have heat and sound insulating properties. Basalt wool is a vapor-permeable material, the rate of vapor permeability equals to 0.25 – 0.35 mg/m2•h•Pa.
Stone (basalt) wool has a number of advantages over glass wool. It is much more durable because basalt thermal insulation doesn’t break even in several decades. Basalt wool doesn’t suffer from changes in temperature; it is a water-resistant and environmentally friendly material. However, the cost of basalt wool is a little higher than glass wool.
Synthetic resins mainly phenolic alcohols are often used as a binder. For this purpose, bitumen, bentonite clay or composite binder (several components) are also used.
One of the main quality parameters is an acidity index, i.e. the ratio between acidic and basic oxides. The classification according to GOST 4640-93:
A – index acidity: 1.6
Б – index acidity: 1.4 to 1.6
B – index acidity: 1.2 to 1.4