Fresh Thinking by Snowden Optiro

Inferred Mineral Resources are the lowest-confidence Mineral Resource category, but what role should they play in mine planning?

In this episode of Fresh Thinking, Tarrant Elkington is joined by Allan Earl, Executive Consultant at Snowden Optiro, to discuss the practical and regulatory considerations around including Inferred Resources in mine plans.

Tarrant and Allan explore the distinction between mine plans developed for operational and strategic purposes and those used for public reporting.

They discuss how Inferred Resources are treated under different reporting frameworks, including JORC, NI 43-101 and S-K 1300, and some of the challenges this creates for mine planners.

The discussion also considers the practical implications of including or excluding Inferred Resources, particularly for long-term and underground mine planning, and the potential for companies to maintain different plans for internal, strategic and public reporting purposes.

Subscribe to Fresh Thinking by Snowden Optiro for more technical discussions from across the mining industry.

When does ordinary kriging stop being the best approach for grade control?

In this episode of Fresh Thinking, Ian Glacken, Executive Consultant, and Dr Gregory Zhang, Senior Consultant at @SnowdenOptiro , explore direct SMU estimation and the circumstances where conventional ordinary kriging may not provide the best result.

They discuss the challenges presented by highly skewed grade distributions, mixed populations and complex anisotropy, and consider alternative approaches including categorical indicator kriging (CIK), multiple indicator kriging (MIK) and localised MIK.

Drawing on a case study, Ian and Gregory examine why different estimation methods should be tested and assessed against reconciliation results, rather than assuming a single approach will work for every deposit.

They also emphasise an important point: more sophisticated estimation techniques are not a substitute for appropriate drilling and good-quality data.

Listen to Fresh Thinking for technical insights and practical perspectives from Snowden Optiro's mining and geology experts.

Changing workplace exposure limits could become an important driver of battery electric vehicle adoption in underground mining.

In this episode of Fresh Thinking by ‪@SnowdenOptiro‬, Hamish Guthrie is joined by Sarah de Vries to discuss Sarah's recent presentation at The Electric Mine Conference 2026, "Evolving Air Quality Regulations: A Catalyst for Electric Machine Adoption."

Sarah explores the changing regulatory environment for diesel particulate matter (DPM) and other airborne contaminants, and what tighter exposure limits could mean for underground mine ventilation, operating costs, productivity and equipment selection.

The discussion also considers the growing role of battery electric vehicles (BEVs) in underground mining, including current technology limitations, ventilation and infrastructure considerations, and the importance of evaluating BEVs within the specific operating and financial context of each mine.

Sarah also shares key takeaways from The Electric Mine Conference, including emerging operating data from mines trialing and operating full BEV fleets underground.

In this episode:

• Changes to workplace exposure limits for DPM
• Implications for underground mine ventilation
• Options for reducing diesel emissions underground
• The role of BEVs in meeting changing air quality requirements
• Current limitations and considerations for BEV adoption
• Emerging operational data from underground BEV fleets

Subscribe to the ‪@SnowdenOptiro‬ YouTube channel for more technical discussions from our mining and geology specialists.

Platinum is one of the world's rarest and most geographically concentrated metals, with applications spanning the automotive, industrial, jewellery and emerging hydrogen sectors. But what does its evolving supply and demand outlook mean for the mining industry?

In this episode of Fresh Thinking by Snowden Optiro, Senzeni Mandava Matondi and Julian Aldridge explore platinum's geology, market dynamics and strategic importance.

They discuss the concentration of global platinum supply, changing automotive demand, the potential role of hydrogen technology, substitution between platinum group metals (PGMs), supply constraints and the challenges of bringing new mines into production.

The conversation also considers what these trends could mean from a mining perspective, including the potential for renewed exploration, mine life extensions and new project development.

Subscribe to Fresh Thinking by Snowden Optiro for more technical discussions covering geology, resource estimation, mining and the commodities shaping the industry.

Was the sample representative?

Every geological model, resource estimate, grade control decision and reconciliation result ultimately depends on the quality of the samples behind it. In this episode of Fresh Thinking by Snowden Optiro, Melanie Bulley is joined by Senzeni Mandava Matondi to explore the Theory of Sampling and why representative sampling is fundamental to reliable decision-making throughout the mining value chain.

They discuss why natural heterogeneity makes sampling challenging, the difference between correct and incorrect sampling errors, why precision should not be confused with representativity, and why even highly precise laboratory analysis cannot correct a sample that was unrepresentative from the beginning.

The episode also explores the practical consequences of poor sampling, including ore loss, dilution, poor reconciliation and unreliable resource estimates. In this episode:

• Why sampling is the foundation of mining data
• Understanding representativity and natural heterogeneity
• Correct vs. incorrect sampling errors
• Precision vs. representativity
• Why laboratories cannot fix poor sampling
• The impact of sampling on grade control and reconciliation
• Principles of good sampling practice

Tailings Mineral Resource Estimates can appear straightforward. The material has already been mined, crushed, processed and deposited in one location — but tailings facilities present their own unique set of technical challenges.

In this episode of Fresh Thinking by @SnowdenOptiro , Senzeni Mandava and Melanie Bulley explore the nuances of estimating Mineral Resources within tailings facilities. They discuss how tailings differ from conventional in situ deposits and why depositional engineering, rather than natural geological controls, can become fundamental to understanding continuity.

opics covered include:

• Density and moisture uncertainty
• Sampling unconsolidated and saturated material
• Variography and spatial continuity in tailings • Depositional history and hydraulic segregation
• The importance of the phreatic surface and hydrogeology
• Metallurgical recoverability and project economics
• Mineral Resource classification
• Tailings reprocessing, critical minerals and ESG considerations

As Senzeni and Melanie discuss, a tailings facility is not simply a relocated orebody. It is an engineered, evolving sedimentary system with its own geotechnical, hydrogeological, metallurgical and operational complexities.

In Part 2 of our Fresh Thinking by @SnowdenOptiro two-part series, host Melanie Bully is joined by Senzeni Matondi to continue the discussion on why the most expensive mistake in grade control isn't necessarily mining low-grade material — it's making the wrong decision about whether material is ore or waste.

Following on from Part 1, this episode explores how mining operations can make better grade control decisions by understanding and managing uncertainty.

Melanie and Senzeni discuss why average grade alone doesn't tell the full story, how conditional bias and grade smoothing can affect ore and waste classification, and why local accuracy around the cut-off grade is so important.

They also explore grade control as a complete value chain — from sampling, QA/QC and geological logging through to estimation, dig planning, mining execution, stockpile management and mine-to-mill reconciliation. The conversation then turns to modern approaches to uncertainty and risk, including conditional simulation, probability-based ore classification and risk-based digline optimisation.

In this episode Melanie and Senzeni discuss:

• Why two models with similar average grades can deliver very different operational outcomes
• Conditional bias and the impact of grade smoothing
• The importance of local accuracy around the cut-off grade
• How ore loss and dilution result from misclassification • Why reconciliation reflects the performance of the entire grade control system
• Moving from deterministic estimates to risk-informed decision-making
• What best-practice grade control looks like at high-performing operations

The key message from this two-part series is simple: grade control isn't about producing the perfect block model — it's about consistently making better mining decisions.

In this episode of Fresh Thinking by Snowden Optiro, Rayleen Hargreaves, Principal Consultant at Datamine and Product Owner of Reconcilor, talks with Ian Glacken, Executive Consultant at Snowden Optiro, about the importance of reconciling mineral resources and reserves across the mine value chain.

Resource and reserve reconciliation is often given less attention than the production stages of the mining process, yet it provides an important link between what a company reports, what it plans to mine, and what is ultimately produced.

Rayleen and Ian discuss:

• The role of resources and reserves in the mine value chain
• The differences between mineral resources and mineral reserves • Why resource and reserve reconciliation is important
• The value of monthly reconciliation and early warning indicators
• Why reserves need to be represented as a model that can be depleted
• How to approach reconciliation when mining occurs outside the reported reserve
• The relationship between resource, reserve and grade control reconciliation
• The growing importance of transparency and reconciliation in reporting codes

The discussion also considers potential changes to the JORC Code and the role that resource and reserve reconciliation could play in improving transparency for companies, shareholders and other stakeholders.

What if the most expensive mistake in grade control isn't mining low-grade material — but making the wrong decision about what is ore and what is waste?

In this two-part episode of Fresh Thinking by Snowden Optiro, Senzeni Matondi, Principal Consultant, joins Melanie Bully, Senior Consultant, to explore why grade control is fundamentally a decision-making discipline, not simply a grade estimation exercise.

In Part 1, Senzeni and Melanie unpack the operational and financial consequences of misclassification, including:

• Ore loss — when valuable material is classified as waste and potentially lost forever
• Dilution — when waste enters the ore stream, reducing head grade and consuming valuable processing capacity
• Misclassification — and why it can result from accumulated uncertainty across sampling, geological interpretation, estimation, blast movement, survey accuracy and mining execution
• Reconciliation — and why poor reconciliation can reflect issues across the entire mining value chain, rather than the resource model alone

The key takeaway? A technically sound grade estimate is only useful if it supports the right operational decisions.

If your resource model is statistically robust, why doesn't it always reconcile with production?

In this episode of Fresh Thinking by Snowden Optiro, Melanie Bulley and Senzeni Mandava Matondi explore why good resource estimates can still lead to disappointing reconciliation results.

They discuss the impact of grade smoothing, explain the concept of conditional bias, and explore why reproducing the average grade is only part of the story. The conversation also covers practical techniques used by resource geologists to assess estimation performance and improve local predictions that support better mining decisions.

Whether you're working in resource estimation, grade control or mine reconciliation, this episode offers practical insights into bridging the gap between statistical accuracy and operational performance.