Q. What is Blast Furnace Slag?

A. ASTM defines slag as A:... "non-metallic product, consisting essentially of silicates of calcium and other bases, this is developed in molten condition simultaneously with iron in a blast furnace.

Q. What is air cooled blast furnace slag used for?

A. Processed slag products include:granular road base,and fill, aggregates for asphalt. sealcoating, concrete and roofing, as well as a raw mineral for manufacture of rock wool.

Q. Where is blast furnace slag used?

A. Structural Concrete..........All construction uses, interior and exterior.
Concrete Paving...................All types of concrete paving, sidewalks, curbs, slabs and structures.
Concrete Masonry Units.....Lightweight block.
Aggregate Base....................Used under both portland cement concrete and bituminous concrete paving.
Bituminous Concrete............All types of binder and wearing courses.
Rail Ballast...........................Used on main lines of major railroads and spur track ballast for plant service.
Roofing Systems...................Slag aggregate surfacing for built-up roofs.
Specialty Applications...........Raw material for rockwool or mineral wool
                                                 Insulation production
                                                 Chip and seal surfacing
                                                 Slurry seal surfacing
                                                 Glass making raw material
                                                 Filter media applications
                                                 Soil conditioning
                                                 Cement manufacture
                                                 Sufacing for playgrounds, driveways and ball diamonds
                                                 Hard lap granules on asphalt shingles

1. More material in every ton:

Air cooled blast furnace slag is approximately 12% to 16% lighter by weight compared to limestone products.

  This means you get 12% to 16% more product in terms of cubic yardage by volume. Fabick Tractor Co. typically sells local quarries 980G wheel loaders equipped with a 7 1/2 cubic yard bucket to load tractor trailers with 3 passes. Fabick sold Beelman a 980G loader equipped with a 8 1/2 cubic yard bucket to load slag, however it takes 3 1/4 passes per trailer load. Gary Crane with Fabick agrees, a typical 25 ton trailer load of Beelman slag will contain approximately 5 1/2 additional cubic yards of material over limestone.

  IDOT recognizes the volume gain on CA-6 coarse aggregate bids, therefore there is a hugh competitive advantage when using slag. This is compounded when factoring in hauling and laying cost.

2. Base and ballast:

  Crushed air cooled blast furnace slag CA-6 provides an excellent base for pavement structures and concrete slabs. This product does not swell and is IDOT approved as CA-6, A Pugged and FA-6. 100% compaction can be obtained with a vibratory roller with 1/2 of the compactive effort when compared with natural crushed stone. Blast furnace slag is 100% crushed, very angular, with few elongated pieces and is without organic or clay contamination. Blast furnace slag granular materials provide for free draining and extremely stable base and sub-base structures.

3. Bituminous and skid resistant surfaces:

  Since air cooled blast furnace slag is durable, hard, very angular, resists polishing and is nearly dust free, it has been frequently used in bituminous skid resistant pavements. It is a premium product specified in IDOT mix designs desgnated as CM-13. Air cooled blast furnace slag is used extensively as a premium seal coat material. It actually extends the life of the sealcoat surfaces and is nearly dust free.

4. Mineral wool insulation:

Air cooled blast furnace slag is one of the raw materials used to make mineral or rock wool insulation.

5. Other uses:

  Other uses of air cooled blast furnace slag includes slope stabilization, driveway topping, fill, gabian stone, ice control, tricking filter medium, glass manufacture, landscape stone, roofing, soil conditioning *, ready mix concrete and precast concrete products. It is also approved by the State of IL. as aglime. Air cooled slag is available crushed and screened in sizes ranging from 4 inch to sand grades. Jerry Hamman with Keller Const. stated. "WE used air cooled blast furnace slag, FA-6 to build two bridge cones in the adverse weather conditions of January and Febuary. FA-6 allowed us to achieve high compaction. We also used CA-6 slag over the years as a base stone. The material is a superior base stone with minimal rolling".

Environmentally Friendly:

  From the ecological point of view there are important and objective advantages to the use of a recycled by-product," air cooled blast furnace slag." It should be emphasized that more and more communities are becoming oriented towards greater consideration for environmental damage, and are doing all that they can to find the economic resources to solve these problems. With regard to the quarrying of aggregates the plans for new quarries have been blocked by environmental groups in areas of this country. In this respect the use of slag might contribute in extending the lifetime of each quarry connected with the aggregate industry. Depending on the specific local situation, each one of these points are extremely important and everybody can appreciate the advantages.