Abstract: Slag sand and slag wool are formed by a method wherein molten slag is poured at a temperature above 1300.degree. C. in a thin flowing stream onto a vaned drum rotating at a peripheral speed of at least 25 m/sec. This drum, which may have forwardly directed nozzles for mixing the falling slag stream with a cooling medium such as water, breaks the slag up into droplets and projects these droplets through the air so they cool and form filaments and granules. The granules are collected separately from the filaments so that the installation simultaneously produces slag sand and slag wool.

Abstract: Molten metallurgical slags are expanded by contact with water in a liquid or vapor state by passing the molten slag along a prefoaming or expanding trough by delivering the slag to this trough via an intermediate trough which is shiftable along the prefoaming trough in order to vary the location at which the slag contacts the prefoaming trough and the expanding-agent film thereon in accordance with physical characteristics of the molten slag, especially its temperature and viscosity. From the pre-expanding or prefoaming trough, the partially expanded slag may be subjected to expansion by conventional means, e.g. a rotating drum which disperses the slag particles through the air so that they can be collected in a completely expanded, dry and solidified state.

Abstract: Molten metallurgical slags are expanded by contact with water in a liquid or vapor state by passing the molten slag along a prefoaming or expanding trough by delivering the slag to this trough via an intermediate trough which is shiftable along the prefoaming trough in order to vary the location at which the slag contacts the prefoaming trough and the expanding-agent film thereon in accordance with physical characteristics of the molten slag, especially its temperature and viscosity. From the pre-expanding or prefoaming trough, the partially expanded slag may be subjected to expansion by conventional means, e.g. a rotating drum which disperses the slag particles through the air so that they can be collected in a completely expanded, dry and solidified state.