Why is rockwool insulation used?

Rock wool or mineral wool is a more compacted less friable type of molten silica (glass) wool for use as insulation it usually comes in boards or sheets of insulation from 1 to 6 inches thick. It is fairly stiff but slightly bendable it is easy to cut and shape and can be nailed or tacked into place. The heat rating and melting temperatures of rock wool are higher than fiberglass. It is usually used in industrial settings for kilns, industrial boilers, ovens and furnaces.