Cement manufacturing places high demand on energy and materials, but provides many opportunities to recover and reuse by-products and industrial wastes.

Fuel
Cement kilns have traditionally used mainly fossil fuels for combustion. The use of alternative fuels and materials can reduce fuel costs, cut carbon emissions, and provide society with environmentally sound methods of waste disposal. But alternative fuels must be well managed to comply with local regulations and meet stakeholder concerns.

Material use
Lowering the percentage of clinker in our cement by substituting other substances not only reduces energy use, but also is a key to reducing our use of natural raw materials. Strength and durability are paramount for ensuring our products are safe to use, so we must find cost-effective clinker substitutes that provide these qualities.

Another way to optimize material use is to improve monitoring at quarries to better control the variability of raw materials and ensure a consistent mix. Our process specialists have developed a methodology that reduces the variability of raw materials entering the kilns, reducing raw material waste and improving energy efficiency

By-product management
A small number of our production plants generate cement kiln dust (CKD), our main by-product.

This is a fine-grained substance removed from process exhaust gases. CKD is extracted to reduce concentrations of sodium and potassium in cement. Large amounts can be reused in the production process.

We can reuse some CKD directly in our finished products, while some requires treatment prior to reuse. It is also a suitable stabilizing agent for waste and environmental remediation. In very few cases, when not reused in production or recycled, it is mostly land-filled.

We aim to keep CKD to a minimum, and are seeking new beneficial uses for any that is produced. Potential markets include using it as a soil conditioner in agriculture and as an acid neutralizing agent in water treatment.

Water
Water is becoming an increasingly scarce resource and several factors, including climate change, are expected to increase the number of regions suffering from drought and water stress.

In cement production, water is used primarily for cooling or in preparing slurry in kilns that use a wet process. The amount of water used in cement production ranges from 100 liters to 900 liters per metric ton of clinker, depending on the process.

Water is also an essential resource for producing concrete. It is used in the production process itself, for cleaning down plants and equipment, in truck wash systems, and for washing aggregates.

For all of these reasons, we manage our water use very closely. We constantly look to reduce consumption, preserve quality, and conserve water resources and wetlands.