TRACKING OUR ENVIRONMENTAL PERFORMANCE MORE CLOSELY
Lehigh Hanson Canada (LHC) is designing and implementing Environmental Management Systems (EMS) across its four divisions: aggregates, cement, concrete pipe and concrete products, including ready-mix concrete. The EMS technologies help facilities track, manage and improve environmental performance.
LHC performs environmental compliance audits regularly to ensure continued improvement and long-term stewardship.
IMPROVED WATER MANAGEMENT & MATERIALS RECYCLING
Lehigh Hanson Canada (LHC) minimizes its use of water by reusing and recycling water at every opportunity through on-site filtration and treatment of the process water; much of our concrete products are made with recycled process water. When discharges are unavoidable, waste water is treated and monitored to ensure it will not have significant impacts downstream.
Many of our sites are also set up to recycle returned concrete into OCTA-BLOC®. These are then available for other industrial uses and environmental controls such as maintaining and containing stockpiles.
AMBIENT AIR MONITORING
Lehigh Hanson Canada (LHC) recognizes that large-scale industrial facilities are viewed as primary contributors to air quality. LHC's cement manufacturing facilities operate Continuous Emission Monitor Systems (CEMS) on all stack emissions. In addition to these, our cement facilities have completed air dispersion modeling exercises that have been published publically in the associated jursdictions. Ambient air quality monitoring is conducted regularly.
WASTE AS A RESOURCE
For Lehigh Hanson Canada, waste materials and by-products from other industries are valuable raw materials and fuels which we use in manufacturing new products. By doing so, we are reducing waste by recycling and preserving natural resources.
LHC's use of alternative raw materials and fuels may also offset the use of virgin resources, and help to supplement or replace fossil fuel energy sources in the manufacturing process.
Here is a list of alternative materials and fuels currently being used at Lehigh Hanson Canada.
IRON SLAG/FERROUS GRANULES
This material represents a source of iron for Lehigh Cement’s Edmonton and Delta plants. It is produced as a by-product from a metallurgical facility in Trail, BC. This waste material is used as an alternative to a virgin source of iron and diverts a usable waste material from entering a landfill.
WASTE IRON GRANULES
Spent granules used in various blasting operations, such as sand blasting, can be used as an iron source in cement manufacturing. Iron granules are diverted from landfill into a useful ingredient in the mix.
Bottom ash is a waste product of the coal-fired thermal generating power stations. It is used as a supplemental silica source in the production of cement. It is formed when ash particles grow too large to be carried from the furnace into the flue gas. It forms on the walls or is collected in the ash hopper at the bottom of the furnace.
The dark grey material is normally either landfilled or used as a fill material, typically in coal mines. Instead, Lehigh Cement uses this material as a partial replacement to virgin clay due to its silica content and low alkalis.
Fly ash (like bottom ash) is a by-product of combustion from coal-fired power plants. Fly ash is finer and lighter than bottom ash. It rises with the flue gas where it is collected by the power plant’s pollution abatement equipment (ESP or baghouse).
Lehigh Cement makes use of this waste product as a partial clinker substitute and intergrinds the fly ash with cement to manufacture InterCem®. Using fly ash helps Lehigh Cement lower its greenhouse gas footprint. The creation of InterCem® also helps downstream users of cement by creating a consistent product with a ‘pre-mixed’ quality, freeing up storage space at the concrete production facility.
RECYCLED CONCRETE AND AGGREGATES
Waste concrete is crushed, screened and reused as aggregate for bulk fills, bank protection, drainage structures and in new concrete pours if possible.
WASTE TIRES AS FUEL
Waste tires are used as fuels in kilns, partially replacing the use of coal. The high heating value of waste tires helps to reduce the nitrogen dioxide (NOx) emissions at cement plants.
COMMERCIAL-GRADE CONTAMINATED SOIL
Contaminated soil is diverted from landfill when used in cement kilns as a partial replacement for raw shale feedstocks. Any contamination is safely destroyed within the cement kiln. The residue is used in the production of cement.
PURE SILICA GEYSERITE
Geyserite is a reddish waste product from silica mining that is considered a contaminate for pure silica. Geyserite used in cement reduces the amount of material that would otherwise be sent to the landfill.