AN IMPROVED PROCESS FOR THE PRODUCTION OF PORTLAND SLAG CEMENT USING GRANULATED BLAST FURNACE SLAG

摘要

A process for preparing a Portland slag cement is disclosed wherein a conventional cement clinker is prepared and ball-milled for 30 to 60 minutes under dry condition s. Granulated blast furnace slag is reduced to a size ranging between 210 and 100 .mu.m and then wet milled for 5-15 minutes in an attrition mill with a slag-to-water ratio of 1:1 to 1:2 and a slag-to-grinding-ball ratio between 1:5 and 1:15 to obtain a slurry. The slurry is dewatered and dried. The Portland slag cement is obtained by intimately mixing 50 to 95 wt.% of the attrition- milled slag; 4 to 45 wt.% of the ball-milled clinker; and 1 to 5 wt.% gypsum for 15-30 minutes. Also disclosed is a Portland slag cement comprising 50 to 95 wt.% granulated blast furnace slag, 5 to 45 wt.% ball- milled clinker and 1-5 wt.% gypsum.