METHOD FOR PRODUCING AMORPHOUS BLAST FURNACE SLAG AND RECOVERING RETAINED HEAT

摘要

PURPOSE:To produce slag contg. amorphous materials at specific rates stably in the stage of cooling molten blast furnace slag by a dry system or the like by cooling the slag at specific cooling rates down to specific temps. thereafter cooling the same slowly stepwise down to specific temps. at a specific cooling rate. CONSTITUTION:In the stage of cooling molten blast furnace slag by a dry system or gas/liquid system, the slag is cooled quickly at =20.0 deg.C/sec cooling rate down to 1,200 deg.C from right after the start of cooling by granulating the slag by the flow of gases or mists., and the hot wind thereof is recovered. Thereafter, the slag is cooled stepwise as slowly as possible at =5.8 deg.C/sec cooling rate from 1,200 deg.C down to 1,100 deg.C, at =2.5 deg.C/sec from 1,100 deg.C down to 1,000 deg.C, and =0.3 deg.C/ sec from 1,000 deg.C down to 850 deg.C, and the hot wind is recovered. Thus the heat retained by the slag is recovered advantageously and easily, and the slag contg. =95% amorphous materials is produced stably.