The Reality of Outlying Projects

For projects requiring tens or hundreds of thousands of tonnes of material, the distance between the source of the aggregate and the project site can become a significant consideration. Transporting large quantities of material over long distances adds truck movements, fuel consumption, road wear, handling requirements and cost.

In these circumstances, on-site crushing and screening can provide an alternative approach: rather than transporting aggregate to the project, the project can potentially process suitable material available on or near site.

The challenge of sourcing aggregate remotely

Commercial quarries provide an established source of construction aggregate, but they are not necessarily located close to every project. This is particularly relevant for projects in remote areas, including renewable energy developments, mining operations and large infrastructure projects.

A project may have suitable rock available on site or within the project area, while the nearest commercial source of the required aggregate could be a significant distance away. The challenge then becomes a logistical one. If a project requires a large volume of aggregate, every additional kilometre between the source and the project can increase the amount of time, equipment and resources required to move that material. There may also be practical limitations. Local road infrastructure may not have been designed for continuous heavy vehicle movements, while site access can be restricted or affected by terrain, weather and other construction activities.

Bringing the processing to the material

Mobile crushing and screening provides a different approach to aggregate supply. Instead of extracting, processing and transporting finished aggregate from a distant commercial source, suitable rock available within the project area can potentially be processed closer to where it will ultimately be used.

The concept is straightforward:

Source material → crushing → screening → finished aggregate

Rather than moving large quantities of finished aggregate over long distances, the processing operation is brought closer to the material source and the point of use.

Is there suitable material available?

The first consideration is the material itself. The presence of rock on a project site does not automatically mean it is suitable for every aggregate application.

The characteristics of the source material need to be understood, including factors such as:

• Rock type
• Hardness
• Abrasiveness
• Natural particle size
• Feed size
• Moisture and fines content
• Expected production volumes
• Required final products

The required end product also needs to be established. A project may require G5, G6 or G7 materials, concrete stone, road stone, ballast, rip rap or other aggregate products. Each application can have different requirements for particle size, grading and material properties.

Reducing the movement of material

One of the potential advantages of on-site processing is the opportunity to reduce the distance that finished aggregate needs to travel. If aggregate is produced closer to where it will ultimately be used, the project may be able to reduce some of the truck movements associated with importing material from a distant commercial source.

This can reduce the amount of material handling required between source and application and may also reduce pressure on access roads and surrounding road networks. For large projects, where aggregate volumes can be substantial, these logistical considerations can become an important part of overall project planning.

The objective isn’t necessarily to eliminate all haulage. Material will still need to be moved around the project site. The opportunity is to shorten the overall supply chain by producing suitable material closer to its point of use.

Bringing the solution closer to the project

For major projects, aggregate supply is a logistical consideration as much as a production consideration. Where suitable rock is available but commercial aggregate sources are remote, mobile crushing and screening can provide an alternative by bringing the processing capability closer to the project.

The starting point, however, should always be the project itself: what material is available, what products are required, how much is needed, and where will it ultimately be used?

Once these factors are understood, the feasibility of on-site processing can be assessed as part of the wider project strategy.

For remote road, mining and renewable energy developments in particular, producing suitable aggregate closer to where it is required can help simplify the material supply chain and reduce unnecessary movement of finished material.