Optimising investment in open-pit mines and large quarries

by Guido Hesse (FAM) and Ulf Gläsmann

Altering the operating parameters of an open-pit/open-cast mine or quarry is never an easy task, and it is certainly not cheap. Systems such as in- or off-pit crushing and conveying systems (IPCC) are complex, and materials may need to be transported over long distances and challenging terrain. Replacing old equipment with new – often in a different configuration – can be a logistical challenge. It takes time and effort to coordinate multiple different suppliers, oversee the installation of the right equipment in the right order, and ensure that the new systems are working correctly, both individually and collectively. Training staff to become proficient with the new set-up is also essential. It’s unsurprising that mine and quarry operators and their financiers are showing unease about the scale of investment and the likely profitability.

 REDUCING CAPITAL COSTS

Increasing capacity, relocating spoil heaps, or reconfiguring a process does not necessarily entail replacing all the existing equipment with new models. A hybrid approach that reuses and repurposes existing components and equipment wherever possible can be a much more economical solution. For example, let’s take a bucket wheel excavator with a 4000 tonnes per hour capacity. A new replacement could cost around €30 million, depending on its features. However, upgrading or refurbishing costs significantly less and can extend the operational life of the existing excavator by 15 years or more, supporting sustainable mining practices.

Accurate investment calculations are essential in making a final decision but a hybrid solution that combines refurbished equipment with new equipment can yield savings of 50% or more compared to the ‘all-new’ equivalent.

The hybrid approach offers multiple opportunities for saving costs, including:

• Lower total investment requirement, which reduces interest on borrowing.

• Less need for complete overhauls and new purchases, which are more expensive and sometimes more complex.

• Shorter delivery timescales, as time-to-production for new equipment is longer.

• Reduced transport costs, as less new equipment needs to be shipped from the manufacturing locations to the final installation site.

• Lower depreciation, because the existing plant is being reused and upgraded where possible.

• Improved operating expenses (OPEX), due to the use of existing spare parts and enhancements in performance due to overhauling or upgrading current equipment.

It is important to note that, by law, any older equipment that is reused must comply with current regulations and standards, ensuring a hybrid design delivers comparable performance improvements to a new system.

ADDITIONAL BUSINESS ADVANTAGES

Using a combination of old and new equipment in open-pit mines and quarries can undoubtedly deliver further business advantages.

 Improved sustainability

This approach supports more sustainable operations by leveraging the usable life of existing machinery, thereby reducing waste and the need for new resources. Ensuring that all equipment, whether old or new, meets the latest standards and regulations supports compliance, minimises environmental impacts and makes for a safer working environment.

 Greater efficiency

Improved efficiency is another benefit. Combining old and new enables existing equipment to benefit from technological improvement while maintaining its proven functionality. One example is the integration of new sensors and controls on older equipment to enable a higher degree of digitalisation. Retaining familiarity with existing systems minimises the need for additional training and makes it easier to estimate operational costs. Combining equipment such as this can even lead to improvements in energy consumption, emissions and overall performance.

 Operational flexibility

A hybrid approach also allows for customisation and scalability, as machinery parts or whole system components can be replaced or upgraded as needed or even used in a different location within the mining plant, without incurring the cost of a full replacement. A hybrid solution contributes to a smaller environmental footprint, as well as reduced after sales service costs, increased safety, and operational simplification. In a flexible solution such as this, the addition of digital features including data collection and analysis create adaptation recommendations which are truly invaluable.

 ACHIEVING OPTIMAL VALUE

The key to success and optimal cost savings and other benefits associated with a hybrid equipment approach is to work effectively with a highly qualified engineering partner who has many years of extensive practical experience and technical expertise.

The customer-supplier relationship is pivotal for success. The scope of the project must be clearly defined, based on a detailed assessment of existing equipment and a clear understanding of operational needs and targets. Therefore, it is imperative to establish effective communication with your chosen engineering partner from the outset, to ensure that the project aligns with operational requirements and sustainability objectives.

In addition to identifying the equipment requirements, consideration should be given to the long-term support and maintenance management required to ensure that an operation derives ongoing value from the investment.

To optimise efficiency and sustainability of dismantling/assembly, it is essential to look for a partner who has an established local setup or can mobilise one to assist with any tasks at hand, mainly planning, execution and maintenance of the plant. The integration of manufacturing capabilities in the destination country can support the local regional economy and reduce the carbon footprint that would otherwise be characterised by transporting heavy machine parts over long distances.

It’s incredibly important to check whether your engineering partner offers any form of guarantee or warranty for the upgraded components. For instance, if the new mining plant design needs to operate for 20 years, a warranty up to 24 months on refurbished or upgraded components could be reasonable.

ROLE OF REVERSE ENGINEERING

Reverse engineering is critical in cases where no data about old parts or machines is available (for example, due to loss of records or machine obsolescence) and enables necessary drawings and other data to be created from detailed modelling of the existing components. It enables accurate identification of which older components can be integrated into the new system, reducing the need for entirely new equipment to deliver cost-savings and improved sustainability by reducing waste and promoting the circular economy. Your chosen engineering partner should have excellent reverse engineering credentials, as carrying out this kind of optimisation requires an experienced engineering company who is familiar with all relevant norms, regulations and technical backgrounds.

The engineering partner you select will be capable of inspecting each piece of machinery to initially ascertain the requisite intervention needed. Then, they will identify parts that are structurally relevant, and which are functionally necessary. This information is then applied when considering if a component can be reused or repurposed, whether it requires an upgrade or even if an entirely new part is required. This detailed survey should extend to any ancillary equipment such as drives, switches, control stations, hoists and so on.

The result will provide a detailed checklist that outlines the required intervention – and therefore the financial investment – required for every component to achieve the agreed-upon business goals. This checklist can then be used to clarify who is responsible for each action, so that labour and time inputs are optimised.

CONCLUSION

Many mining and quarrying operations delay capital investment decisions because they believe new equipment is simply unaffordable. However, working with a trusted engineering partner that understands mining and quarrying equipment and the commercial imperatives can enable a hybrid approach that reuses existing assets wherever possible to significantly reduce the investment requirement and deliver the project in less time. This not only improves your balance sheet but offers higher efficiency, extends equipment life, ensures compliance and competitiveness, and fosters more sustainable working practices.