Fresh Thinking: The 3-Minute Read. Episode 115

Here’s your 3-minute quick read of Fresh Thinking by Snowden Optiro’s podcast Episode 115.
We’ve pulled out the key insights and takeaways – perfect for when you want the value, minus the headphones.

What Resource Geologists Should Know About Mine Planning

Fresh Thinking Podcast Ep. 115 with Hamish Guthrie and Gregory Zhang

In this episode of Fresh Thinking, host Gregory Zhang sits down with Hamish Guthrie, Snowden Optiro’s Managing Consultant in Mining, to unpack what every resource geologist should know about mine planning. With over 25 years of experience, Hamish offers a clear and practical breakdown of how geological data feeds into effective mine design – and why collaboration between geologists and mining engineers matters more than ever.

From Geology to Mining Inventory: The Workflow

Hamish outlines the foundational steps of mine planning, beginning with the geological interpretation and the resource model. Once geologists deliver the model, mining engineers apply modifying factors such as mining losses, dilution, and excavation constraints (like pit slopes and minimum mining widths for open pit mines, or stope spans for underground operations).

From there, cost and revenue assumptions come into play. These help generate a mineable inventory and support pit optimisation, scheduling, and project evaluation via metrics like Net Present Value (NPV). As Hamish puts it, understanding “what the mining implications of the geology are” is a critical step in shaping viable plans.

Why Resource Confidence and Sensitivity Matter

Gregory and Hamish emphasise the importance of resource classifications – Measured, Indicated, and Inferred – and how these influence mine plans. Whether to include or exclude low-confidence material is a judgement call, but visualising how resource confidence plays out across the mine schedule can inform key decisions around capital investment and sequencing.

Adding detail to confidence metrics – beyond standard classifications – can also add value. For example, flagging areas of low sample density or estimation quality can help identify where additional drilling is needed or guide when to apply grade control.

Is Estimating in Waste Domains Worthwhile?

Yes, says Hamish – especially when waste material contributes to dilution, affects productivity, or has potential to be reprocessed. Including basic estimates for waste rock properties can also inform tailings management, dump design, and environmental planning – especially in today’s ESG-conscious climate. As Gregor notes, geologists already spend time collecting data, so making it mine-planning-ready doesn’t require much extra effort – just clarity on what’s needed.

What Else Should Be in the Model?

Hamish encourages resource geologists to include as much relevant information as possible. This includes:

• Depletion and voids – Not just surveyed depletion, but areas that may have been mined or sterilised.
• Geometallurgical data – Characteristics that impact processing performance or costs.
• Geotechnical properties – Particularly for slope design, underground stability, and productivity assumptions.
• Environmental indicators – Especially potential acid-forming waste materials, which affect long-term dump stability and environmental risk.

Even if a project isn’t in production yet, Hamish highlights the value of including early-stage estimates in the model. “Any data you can get early helps you down the track,” he says.

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Want more on mine planning?
Check out earlier episodes: Ep. 62 on open pit and Ep. 66 on underground planning. And if you enjoyed this conversation, subscribe to the Fresh Thinking podcast on YouTube or your favourite podcast platform.

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🎧 Catch the full conversation in Episode 115 on your favourite podcast platform, or share this summary with colleagues who might be sitting on untapped value.

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Watch or listen to the full episode
Available now on YouTube, Spotify, Apple Podcasts, and all major platforms.

Stay tuned for more 3-minute articles from our Fresh Thinking 3-Minute Read series.

If you would like to contact either Tarrant or Pedro: contact@snowdenoptiro.com

Here is a LINK to our Snowden Optiro YouTube channel.

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.

LINK to Snowden Optiro website