Current developments in the manufacturing
and utilization of granulated blast furnace slag
August 2009 in comparison to 2008
Summary: Due to the necessity to reduce CO2 emissions in cement making the partial substitution of cement clinker by granulated blast furnace slag (GBFS) has become established. This article deals comprehensively with the granulation process of GBFS as well as with the effects of the granulating process on the properties of GBFS. However, the properties of GBFS may further be optimized in the cement plant, mainly during the grinding process. In the future also artificial slags or slags from other technical processes with suitable properties could perhaps be used as clinker substitutes.
Because of its latent-hydraulic properties, granulated blast furnace slag (GBFS) has been employed as a cement component and as a concrete additive for more than 100 years. Formed from liquid blast furnace slag, it is a by-product of hot metal production in blast furnaces and thus of the steel manufacturing process. 65 % of all the steel manufactured worldwide comes from the blast furnace/LD converter while only 35 % is produced by the electric furnace process. GBFS is created by the dispersion and extremely rapid cooling of liquid blast furnace slag by means of water or air...