Clean Mining: how environmental goals and demands for higher productivity are driving profitability and investment decisions

By Guido Hesse, FAM 

MINING TRANSPORT EVOLUTION

Human beings have been extracting materials such as iron and copper ores for more than a thousand years. The technology available to transport these materials from the point of extraction to places where they can be processed and then on to their final point of use has evolved gradually over time.

Horses and mules gave way to rail transport as early as the 1500s and minecarts continued to be deployed into the early 20th century. The first dump truck did not appear until the 1930s. Developed specifically to address the increasingly industrialised nature of mining, the design evolved throughout the 20th century to increase power and payloads. Today, most mines rely on large fleets of ‘monster’ shovel/dump trucks as the tried and trusted method of moving bulk materials around.

However, the growing impetus to reduce environmental impacts and make mining operations more sustainable and efficient without massively increasing costs is challenging this truck-based mode of haulage.

THE TROUBLE WITH TRUCKS

Diesel-driven trucks deliver low sustainability and high emissions, as well as consuming lots of natural resources such as rubber for tyres – not an ideal combination for an industry aiming to improve its environmental performance and mine efficiency. Reliance on trucks means that mines are producing aggregates with a high carbon footprint. While the use of hybrid vehicles may reduce CO2 emissions somewhat, depending on mine size, they are not yet a permanent solution and do not support a clean mining model or efficient mine operation.

In addition to the cost to the planet, we need to factor in the cost to the mining company. Establishing a fleet of trucks is an expensive exercise. A single large heavy duty truck could cost several million euros. In addition, whole road networks need to be constructed and maintained, and a service location to maintain and repair the fleet is required.

Trucks not only represent a high capital cost: the operational costs associated with running a fleet are also considerable. A truck can typically travel more than 120,000 miles in a year over rough terrain and dirt roads. Field service and support to keep a fleet operational can represent as much as 15-20% of mine equipment costs. The wear and tear means large heavy duty trucks generally need replacing every 8 to 10 years – three or four times during the lifetime of the mine. Truck efficiency decreases dramatically after the first few years, so maintenance and replacement costs are therefore a significant overhead – particularly where multiple trucks are needed for volume conveying.

Other disbenefits associated with trucks include inefficient routing (due to factors such as sight, stopping distances and mine topography); high dust pollution, noise emissions and safety risks; and potential disruption due to adverse weather conditions.

All things considered, the time has come for a paradigm shift in the way we approach mine planning and operations in the 21st century.

OVERHAULING HAULAGE 

In-Pit Crushing and Conveying (IPCC) is a much more efficient approach to mining haulage that largely removes the operational, environmental and safety concerns associated with trucks while driving down total cost of ownership (TCO).

Essentially, IPCC seeks to automate the transportation of materials around the mine, while being sufficiently flexible to support the way mining operations evolve during their lifetime. This approach can eliminate the need for truck haulage altogether from crusher infeed up to the dumping area of overburden or to intermediate storage places or loading points.

Each IPCC system will be unique depending on the mine’s layout and operational priorities, but typically it comprises a series of conveyors, feeders, crushers, stackers or dumping spreaders that replace the large-scale deployment of trucks. Beside fixed crushing stations the operation with a semi- or fully-mobile crushing concept increases the operational mine flexibility. Their modular design offers the scalability and flexibility to adapt to changing mine layouts and production requirements.

 IPCC vs. TRUCKS 

There are several reasons for mining operations to consider the switch from trucks to IPCC:

• Environmental benefits: IPCC systems produce fewer greenhouse gas emissions than diesel-powered trucks, especially over longer distances, contributing to a lower carbon footprint for the mining operation. They also generate less noise and dust. In addition, they can reduce the overall environmental footprint of the mining operation by minimising the area disturbed by haul roads and truck traffic.

• Cost savings: OPEX for IPCC systems compares favourably to shovel/truck equivalents, with mine operators saving 30-35%. The combination of lower fuel consumption, 100% savings on truck tyres, lower maintenance costs and lower labour costs significantly reduces the cost per ton of material compared to truck haulage.

• Maintenance/TCO: equipment such as conveyors experience less mechanical wear and tear compared to trucks, leading to longer equipment life and lower maintenance requirements. They also support a more predictive, planned maintenance approach compared to trucks.

• Operational efficiency: unlike trucks, IPCC systems can operate continuously, delivering a predictable material flow that can enhance overall operational efficiency, throughput and availability.

• Improved safety: ​​​​eliminating or reducing truck movements reduces noise and dust and lowers the risk of traffic-related accidents within the mine and any associated disruption while investigations are ongoing.

ADOPTING THE IPCC APPROACH

Clearly, the IPCC approach offers significant benefits over traditional truck haulage. It does still involve capital investments and requires an adjusted approach to mine planning – but when correctly implemented IPCC offers a significant and favourable return on investment, more flexible operations, and reduces reliance on fossil fuels.

To ensure that the system is optimised and will support your mining operations over time it is therefore advisable to work with a suitably experienced specialist who can provide the combination of mining expertise and project management abilities from the outset. Check that they also have the relevant skills in change management and developing compelling business cases so that all stakeholders are engaged and on board. Also consider the ongoing support that an IPCC approach requires, from design and implementation through servicing and maintenance.

(End-of-Line includes loading, stacking or spreading.)

TOWARDS CLEAN MINING

With the right planning and support in place, the IPCC approach can achieve payback within a couple of years, plus accrued savings amounting to millions of euros over the lifetime of a mine, leading to improved mine productivity. ​In addition, IPCC system deployment often creates the potential to increase mine capacity, which supports overall mining efficiency.​

Within large-scale projects, the integration of used existing equipment can be considered to further reduce the total investment and reduce environmental impacts by mitigating the need for new machinery. Using renewable energy sources to provide the electricity for an IPCC system where possible will further contribute to more sustainable mining operations.

In summary, IPCC is a total system solution that is becoming increasingly attractive as part of modern mine planning and mine operations. It may not replace trucks completely, but the IPCC approach certainly means they will no longer be required for mass transport – significantly lowering carbon emissions and costs and advancing the transition towards clean mining and increasing mine profitability.