Enhancing underground mine reconciliation: A unified F and R series framework

Join online webinar on Enhancing underground mine reconciliation.

About this event

Robust reconciliation practices are essential to the governance and performance improvement of mining operations. The F series factors, originally proposed by Parker (2012), assess the accuracy of key planning and operational stages such as reserves, mining, and processing. To extend this framework, the R series factors (Hargreaves et al., 2021) were introduced to examine how modifying factors are applied through the planning pipeline, enabling detailed tracking of ore loss, dilution, and information effects from the resource model to actual production. While both underground and open pit mining present reconciliation challenges, underground operations are particularly complex due to selective mining, limited visibility, and inconsistent depletion methodologies. These differences make reconciliation less straightforward and often less reliable without a methodical approach. This paper focuses on addressing those challenges by proposing a standardised method for calculating R series factors in underground mines. Using a “common volume” depletion strategy, it captures all sterilised areas resulting from mining and planning decisions, enabling spatially valid and consistent comparisons across models. This underground-specific methodology is set against the broader industry context. The proposed revisions to the JORC Code place increased emphasis on reconciliation as a foundation for transparent and defensible public reporting. To meet these expectations, reconciliation frameworks must bridge the gap between reported resources and actual outcomes, regardless of mining method. To demonstrate practical application, a case study from Newmont’s Tanami gold operation is presented. It shows how integrating F and R series factors within a consistent spatial-temporal framework improves insight into reconciliation performance, guides corrective action, and supports model calibration. Tailored strategies for both underground and open pit environments are considered, reinforcing reconciliation as a critical control in achieving financial, operational, and reporting confidence across the value chain.

Speaker/s

Rayleen Hargreaves

Product Owner - Reconcilor / Principal Consultant, Datamine

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Reconciliation across the mine value chain is an often underestimated and underutilised aspect of mining operations – but an area I’m passionate about improving across the industry. Communicating with mine sites globally and across commodities provides me with a solid benchmark for a company within the industry, and I aim to open up these insights to everyone. It’s my career goal to see all mine sites using reconciliation factors in their results to the share market so that anyone can see how a mine site benchmarks against another. My paper on “Transparency and standardisation in metal reconciliation accounting” provides more detail for those interested.

As a mining geologist with over 25 years of experience in the resource industry, I am the Product Owner of Reconcilor, an industry-leading solution to track, manage and reconcile metals across the mine value chain – and a tool that’s saved our customers hundreds of hours in End of Month reporting, and millions to their bottom line in proactive planning.

I provide a leadership role within the R&D team, ensuring the delivery of software features and functionality that meets the needs of key stakeholders. And yes! Reconcilor has reconciliation factors embedded within the product – a feature we’re proud to say is unique to the market.

Utilising my strong domain expertise, I have been involved with the onsite implementation and administration of Reconcilor across mine sites with diversity in minerals, type of operation, and in locations around the globe for the past 15 years.