It ensures a clean metal surface free from Slag by co-agulating the impurities. It forms an Efficient Insulating layer on the top of ladle which significantly reduces the radiant loss of heat that may be maintained until pouring time and hence therefore acts as an insulating barrier. It also reduces Sulphur content and also prevents reentry into the bath when added to ladle by holding them in the slag.It does not produce objectionable smoke or noxious fumes, hence non-polluting. The additional benefit of using Perlite in excess will help reducing contents of Sulphur and Phosphorus.