Abstract
The hydraulic hardening property as well as other properties of water granulated blast furnace slag powder (hereafter refered to as slag) has been widely utilized. Many efforts have been made to fully utilize these properties through particle control of the slag. The usage of an air classifier as the means of manufacturing very fine slag has been suggested and carried out actually. Since the production of very fine slag has become popular and indispensable, the improvement of classifying efficiency is an important and urgent issue. The classifying efficiency of a classifier is remarkably influenced by the degree of dispersion of fed slag. The aim of the present study was to examine the effectiveness of the addition of classifying aids in the classifying process for slag. As the classifying aids, ethanol, diethylene glycol (DEG), and triethanolamine (TEA) were used. The results obtained are as follows:
(1) The efficiency of slag classification was considerably improved by the addition of classifying aids; in particular DEG and TEA were effective under the experimental condition employed.
(2) The effectiveness of the addition of classifying aids could be evaluated in terms of the dispersability measured by a powder-falling test which was employed in this study.
(3) The optimum dosage of classifying aids was almost same as that of grinding aid. However, the functions of the both aids were slightly different.
