Environment & Sustainability

Circular Economy

At Ash Grove North, we are taking a leadership role as Ontario and the rest of the world transitions to a more sustainable economic model – a model focused on natural resource conservation, greenhouse gas reduction, minimized and repurposed waste – not as specific actions, but rather positive outcomes of a new way of delivering the value to society that is expected of business.

The Circular Economy is a concept that looks to move our society from a linear economic system of take-make-waste to one that considers that materials can have a beneficial use beyond their primary purpose. The goal is to minimize the amount of virgin materials and energy entering our production systems, as well as looking for products that can minimize waste at the end of their use to be repurposed or reconstructed into something new.

Circular Economy Mississauga Cement Plant

Top: Linear economy with high natural resource needs and waste disposal (red arrows).

Bottom: Circular economy with maximized material reutilization (blue arrows), minimized natural resource need and disposal (red arrows).

At Ash Grove North, our goal is to be a leader in the shift to a circular economy – it is also a necessity for our resource and energy intensive industry. We are keenly focused on reducing our use of natural resources while simultaneously giving discarded materials a secondary beneficial purpose.

With concepts such as construction shale as raw material feed, petcoke utilization, recovery of waste oils/solvents, and Ash Grove North Slag Cement – the Ash Grove North Mississauga cement plant’s reliance on virgin natural resources is reduced by nearly 50% for fuel and 30% for raw material. Combined, that’s over 500,000 tonnes of material that came from by-products of other industries to make the cement that leaves our Mississauga facility.

We are constantly looking for materials that can be reused in our processes to minimize the amount of raw material or fuel that requires mining. Our aim is to reduce society’s reliance on non-renewable resource extraction as well as avoid useful resources ending up in landfills.

The above image and following examples are some of the ways that Ash Grove North has been transitioning its operations to a circular economy model. We also understand that, unlike the linear economic system, a circular economy cannot operate effectively without the collaboration of industries, communities, and policymakers driving towards a common goal.

Blast Furnace Slag (BFS) is a by-product of primary steel manufacturing. In the process of manufacturing iron (in the blast furnace), a by-product referred to as “slag” is created that is chemically similar to the cement that we produce at our own facilities. The slag still requires physical processing at the cement plant, but does not require any further chemical processing. The slag can be blended with traditional Portland Cement or sold as a separate cementitious product.

This mutually beneficial partnership with the steel industry allows for significant reduction of limestone extraction, thermal energy inputs, and carbon dioxide emissions.

In addition to these benefits, Ash Grove North further reduces its thermal energy for material drying and eliminates sulphur dioxide emissions through the use of slag. Ash Grove North Slag Cement is a great example of circular economy principles applied.

Shale is a sedimentary rock that is all around us. In fact, across the Greater Toronto Area many construction projects require the removal of this abundant material during excavation as new residential, commercial, and institutional buildings are erected. Shale, and more specifically Silica (Si), is required in the production of cement – it is one of the key elemental ingredients along with calcium (Ca), alumina (Al), and iron (Fe).

Although Ash Grove North has access to shale through its own onsite quarry – for many years, Ash Grove North has purposely sought out shale resources from construction projects. This allows construction projects to have excavated shale put to a beneficial use rather than being stockpiled or disposed of while allowing Ash Grove North to minimize the need to extract virgin resources from its own quarry.

Petroleum coke (also known as petcoke) is a by-product of oil production. Although a derivative of fossil fuel, petcoke has a slightly lower global warming potential (GWP) than coal – approximately 3% lower than coal. As a by-product of production, petcoke does not require the extraction of any additional non-renewable resources to produce the fuel. Ash Grove North has taken steps in recent years to incorporate the use this by-product in order to reduce the use of coal.

The use of petcoke not only reduces Ash Grove North’s greenhouse gas emissions, but additionally eliminates the requirements for coal extraction, processing, and transportation as well as the disposal of a suitable fuel in petcoke.