Blast Furnace Slag

Blast Furnace Slag is formed when iron ore or iron pellets, coke and a flux (either limestone or dolomite) are melted together in a blast furnace. When the metallurgical smelting process is complete, the lime in the flux has been chemically combined with the aluminates and silicates of the ore and coke ash to form a non-metallic product called blast furnace slag. During the period of cooling and hardening from its molten state, BF slag can be cooled in several ways to form any of several types of BF slag products.

Blast Furnace: Combustion material and ore are supplied from the top while an air flow is supplied from the bottom of the chamber. This forces the chemical reaction to take place throughout the ore, not only at the surface.

Granulated SlagGranulated slag is rapidly cooled by large quantities of water to produce a sand-like granule that is primarily ground into a cement commonly known as GGBS (Ground Granulated Blast FurnaceSlag), or Type S slag cement. It is also mixed with Portland cement clinker to make a blended Type 1S cement.


Air-cooled Slag,
Blast furnace slag is allowed to slowly cool by ambient air, is processed through a screening and crushing plant and is processed into many sizes for use primarily as a construction aggregate. Common uses are as aggregates in ready-mix concrete, precast concrete, hot mix asphalt aggregate, septic drain fields and pipe backfill.


Pelletized or Expanded Slag
Pelletized or Expanded Slag is quickly cooled using water or steam to produce a lightweight aggregate that can be used for high fire-rated concrete masonry and lightweight fill applications over marginal soils. Due to its reduced weight, it is perfectly suited for aggregate in lightweight concrete masonry, lightweight ready-mix concrete and lightweight precast concrete


Air-cooled Blast Furnace Slag
This smaller sized aggregate is primarily used in chip and seal applications, also known as "Chip Seal" or "Aggregate Seal Coating", applied to existing pavement surfaces. The primary purpose for Chip and Seal is to achieve a skid resistance on rural pavements and to maximize driving safety. It is also used in concrete masonry and hot mix asphalt.




Air cooled blast furnace slag rip rapThe largest slag aggregate, riprap is a permanent cover of rock used to stabilize shorelines and streambanks, and prevent erosion along slopes and embankments. It is also used in gabion baskets, Mineral Wool manufacture (insulation), and lightweight fil


Slag cement,
Slag cement is commonly found in ready-mix concrete, precast concrete, masonry, soil cement, concrete wallboard, floor leveling compounds and high temperature resistant building products. Its measurable benefits in concrete include improved workability and finishability, high compressive and flexural strengths, and resistance to aggressive chemicals