What is mineral wool insulation?
The term “mineral wool” actually encompasses fiber glass and two additional materials – rock wool and slag wool – that use different raw materials in their manufacture. Rock wool is made from natural minerals like basalt or diabase. Slag wool is made primarily from iron ore blast furnace slag. Rock and slag wool fall within a group of materials historically referred to as man-made mineral fibers; however, a more appropriate name is man-made vitreous fibers (MMVFs), reflecting the glassy, non-crystalline nature of these materials. More recently, scientists have also used the term “synthetic vitreous fibers” to describe these materials. Rock and slag wool insulations are produced by a centrifugal wheel process. Natural rocks or iron ore blast furnace slag are melted, and the hot, viscous material is spun into fiber by pouring a stream of molten material onto one of several rapidly spinning wheels. As droplets of the molten material are thrown from the wheel(s), fibers are generated. As t
