Slag - A material that endows cement and concrete

Slag has been employed in cement manufacturing since the 19th century, today being universally accepted as a material that endows cement and concrete with a noteworthy list of advantages. Given that this waste is highly dependent on steel and iron output, both of which are subject to the fluctuations of the macro-economic indicators, cement manufacturers are challenged in finding slag resources.

Blast-furnace slag is the non-metallic product produced at the same time with iron in the last furnace, consisting primarily of silica and alumina from the iron ore, combined with calcium and magnesium oxides from flux materials. For an ore feed grading 60 percent to 606 percent iron, about 0.25 to 0.3 tons of blast furnace slag are produced per ton of crude iron. Steel slag, on the other hand, is a by-product of steel making, produced during the separation of molten steel from impurities in steel-making furnaces.

Read the rest of the article in the CemWeek Magazine, Issue 26.