Viscosity of blast furnace slags and its effects on their applications

The paper discusses the effect of chemical and mineralogical compositions and temperature of blast furnace slag on its viscosity. The importance of viscosity of slags with regard to its applications is also stressed on the basis of literature survey. In the production of heavy aggregate and pumice the 'long slags', the viscosity of which increases very slowly in a wide range of temperature, are preferred. For the production of slag cement, the short slags', the viscosity of which is varying fast, are preferred. The viscosity of slag obtained from various iron and steel plants in Poland and East Germany was determined employing the viscometer installed at the Institute, a brief description of which is also given. The graphs for relationship between temperature and viscosity of these slags are reported and the suitability of the slags under study is discussed. (Shri Narinder Singh and Shri Muthukrishnan, Scientists, National Metallurgical Laboratory, Jamshedpur, and Dr. T. Rogozinski, Head of Slag Laboratory, Instytut Metalurgii Zelaza, Gilwice, Poland)