Lafarge has more than 45 years of slag processing experience in North America and markets over one million tonnes annually. Half of this is expanded into a variety of low-density aggregates that are supplied to customers throughout the Great Lakes and Mississippi River basin. The balance is ground to produce slag cement. In Canada, Lafarge is the largest producer of lightweight aggregates.
Lafarge processes molten blast furnace slag using any of three means: Expanding, pelletizing, and air-cooling. These yield raw materials that can be used for many construction related applications.
In the 1960's, Lafarge developed and patented technology to produce two products: Litex™ brand lightweight aggregate, a vitrified, hard, lightweight aggregate, and Vitrex™ brand pelletized slag, a material that is ground into slag cement.
In the 1990's, Lafarge developed and patented an innovative slag expanding process to produce an even lighter weight aggregate, True Lite Lightweight Aggregate™ brand aggregate. This low-density product is approximately 35 percent lighter than most natural aggregates.
Applications where lightweight aggregates are used include:
- lightweight concrete masonry
- structural lightweight and semi-lightweight cast-in-place concrete
- low-density precast concrete units
- low-density mortars for radiant heat floor and refractories
- geotechnical low-density engineered fill
- insulating concrete fill
- concrete roofing tile and ballast
- ground cover and soil-less mixes
Lafarge is a member of the National Slag Association.