Ep 125: Inside the Black Box: essential guide to plant sampling
Fresh Thinking by Snowden Optiro
Release Date: 09/01/2025
EP 155 | Part 2 of 7: Recoverable Resource Methods
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking by, we explore recoverable resource methods and how they help bridge the gap between resource models and what is actually mined. We discuss key approaches used across the industry, including Uniform Conditioning (UC) and Multiple Indicator Kriging (MIK), outlining how they address grade smoothing and improve predictions at the mining scale. We also cover the strengths and limitations of these methods, particularly their reliance on variograms and their inability to capture uncertainty. This episode sets the stage for the next discussion on conditional...
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EP 154 | Part 1 of 7: Foundations of Modern Resource Estimation
Fresh Thinking by Snowden Optiro
Episode 154 of Fresh Thinking by Snowden Optiro kicks off a 7-part series on modern resource estimation. In this episode, we cover the fundamentals of ordinary kriging, its strengths and limitations, and introduce key concepts like grade smoothing, SMU, and recoverable resources. Featuring Ian Glacken and Susan Havlin.
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EP 153: The Genesis of Australia’s Nickel Industry
Fresh Thinking by Snowden Optiro
Discover the fascinating origins of Australia’s nickel industry in this episode of Fresh Thinking by . Principal Consultant, Jan Graham, sits down with Executive Consultant, Ian Glacken, to explore the pivotal moment that sparked it all—the discovery of nickel at Kambalda in 1966. From early prospecting and geological insight to rapid development and industry-wide impact, this story highlights the role of luck, lateral thinking, and persistence in shaping one of Australia’s most significant mining sectors. Learn how a single drill hole, KD1, transformed Western Mining Corporation and led...
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Ep 152: If You Sign It, You Own It: The Reality of Reserve Sign-Off
Fresh Thinking by Snowden Optiro
What does it really mean to sign off on a mineral reserve? In this episode of Fresh Thinking, Tarrant Elkington (General Manager, Snowden Optiro) is joined by Allan Earl (Executive Consultant Mining) to discuss the real responsibility behind reserve sign-off and what it takes to stand behind it with confidence. From understanding the full value chain to applying critical review across technical inputs, this conversation explores where things can go wrong, and how to avoid it. If you’re working towards becoming a Competent Person, or already signing off on reserves, this is well worth a...
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Ep 151: When Bigger Isn’t Better: Rethinking Resource Model Size
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking by Snowden Optiro, Jamie Oppelaar (Senior Consultant) and Tarrant Elkington (General Manager) discuss a growing challenge in mining: resource models are getting bigger and bigger. More blocks, more attributes, more simulations. While this can improve geological representation, it can also slow down optimisation, scheduling and everyday planning decisions. So how do we strike the right balance between detail and usability? Jamie and Tarrant explore why models are expanding, the practical consequences for engineers, and how geologists and planners can work...
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Ep150: Mineral Resource Estimation: What Really Is “Industry Standard”?
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking by Snowden Optiro, our General Manager Dr Tarrant Elkington speaks with Senior Consultant Dr Gregory (Greg) Zhang about a common question in the mining industry: what is the real industry standard in mineral resource estimation? Drawing on experience reviewing projects across a range of commodities and deposit types, Greg discusses current practices in data management, QAQC, geological domaining, estimation methods such as kriging, and resource reporting. The conversation also explores how practices are evolving and the emerging role of simulation methods and...
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Ep 149: Building Resource Estimation Logic in Excel
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking, Susan Havlin (Managing Consultant APAC) speaks with Dr Gregory Zhang (Senior Consultant APAC) about using Excel as a transparent learning environment for geostatistics. Rather than relying on black-box software, they explore how building the logic step by step in a spreadsheet can strengthen intuition, improve data discipline and deepen technical confidence. Whether you are a geologist, resource modeller or mining professional wanting to better understand what sits behind the software, this episode breaks down the thinking that underpins robust estimation....
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EP 148: Simulation Is Not Estimation - rethinking uncertainty in mining
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking, Ian Glacken (Executive Consultant) and Dr Gregory Zhang (Senior Consultant) discuss one of the most important topics in modern resource modelling: uncertainty. From the long-standing debate of simulation vs estimation, to the growing focus on geological uncertainty and hierarchical truncated plurigaussian simulation, this episode explores where the mining industry stands — and where it still needs to improve. ⏱ Key Topics 00:00 – Introduction: Simulation in mining and why uncertainty matters 01:18 – Simulation vs estimation: what’s the real...
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Ep 138: From Scoping to Feasibility: How to nail cost estimation at every stage
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking by Snowden Optiro, Hamish Guthrie (Managing Consultant – Mining) joins Dr Gregory Zhang (Senior Consultant – Geology) to explore the fundamentals of cost estimation across the mining study pipeline. Hamish shares practical insights from his more than 30 years in the industry, including the importance of understanding project scale and matching the level of effort to the study stage. If you’re involved in study work, project evaluation, cost modelling or operational planning, this conversation will give you clear, practical guidance you can apply straight...
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Ep 134: The Interface Challenge - bridging the gap between geologists and mining engineers
Fresh Thinking by Snowden Optiro
In this episode of Fresh Thinking, Tarrant Elkington (Snowden Optiro General Manager) joins Susan Havlin (Managing Consultant APAC) to explore the all-too-common disconnect between geologists and mining engineers. Tarrant talks about the results from the more than 100 professionals that generously responded to his survey - helping geologists and engineers understand how differences in approach, communication, and expectations can impact project success. Tune in to hear what both sides really think - and how better collaboration can make all the difference. Key Time Points: 0:42 – How...
info_outlineIn this episode of Fresh Thinking, our Executive Consultant (and fellow sampling guru) Ian Glacken sits down with Mark Murphy, world renowned Sampling expert, to uncover the realities of plant sampling - from conveyor belts and moisture balances to concentrates and reconciliation. Mark shares practical insights, cautionary tales, and expert tips to help geologists better understand sampling challenges inside the plant.
If you’ve ever wondered how conveyor belt bias, weightometers, or moisture variability affect your reconciliations, this conversation is essential listening.
Key Timestamps
0:04 – Introduction: Setting the stage for plant sampling and reconciliation.
1:01 – “Never trust a metallurgist?” (Just kidding!) Why geologists and metallurgists often have different priorities.
2:00 – Weightometers & moisture: The two biggest issues affecting mass balance into the plant. 3:00 – Conveyor belts: Why top-belt samplers and fines create bias.
4:50 – Time-based errors: How long conveyors cause cyclic sampling challenges.
6:14 – Homogenisation matters: When material becomes “relatively homogeneous” and why head grade calculation is tricky.
7:30 – Concentrate sampling: Why it’s usually less of an issue than belt sampling.
9:00 – Shark-fin samplers & densometers: Common pitfalls to watch out for in plant sampling setups.
10:26 – Value engineering: How cost-cutting compromises plant sampling accuracy.
12:30 – Collaboration is key: Why geologists, metallurgists, and mining managers must work closely together.
Keep tuned for the final episode of this Sampling series.
Have a question about Sampling or want to get in touch: contact@snowdenoptiro.com
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LINK to Snowden Optiro Professional Development courses - Look for the Sampling Theory and Best Practice course: https://snowdenoptiro.com/events/sampling-theory-and-best-practice/
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Who we are:
Snowden Optiro is a resources consulting and advisory group that provides independent advice, consulting and training to mining and exploration companies, their advisors and investors.
We help mine developers to advance their projects, mining companies to improve their operations and their professionals, and investors to de-risk their investments by the provision of quality advice, training and software in the field of Mineral Resources and Mineral/Ore Reserves.
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