Senior staff engineer, Inland Steel Co., East Chicago, IN
Manager, Technical Service and Product Development, Lehigh Portland Cement Co., Allentown, PA
Currently, Inland Steel Co. generates approximately two million tons/year of iron blast furnace slag. This material is disposed of in a landfill which has a life expectancy to 1995. With the completion of the landfill rapidly approaching, an alternative means of slag disposal is necessary. Based on a review of the literature, it was determined that water granulation is one possible means for upgrading the utilization potential of blast furnace slag. This paper summarizes the results of a 1-ton/min pilot plant investigation (covering 101 furnace taps) aimed at determining if water-granulated slag from Inland's Blast Furnace No. 7, when suitably ground, can be used as a cementitious admixture for concrete and mortar. From the results it was concluded that a product of acceptable quality meeting ASTM Specification for Ground Iron Blast-Furnace Slag for Use in Concrete and Mortars (C 989) can be produced.
The effect of granulator operating controls and chemical composition of slag on product quality were also investigated. For product quality control, the hydraulic index was found to be the best indicator of slag quality. The percentage of silica (SiO2) and alumina (Al2O3) in the slag were found to produce the most significant correlations to the three- and seven-day compressive strengths of the mortar cubes. No significant correlations were observed between operating parameters and the three, seven, and twenty-eight day compressive strengths.
Paper ID: CCA10571J