In Episode 106 of Fresh Thinking by Snowden Optiro, Executive Consultants Ian Glacken and Graeme Lyall discuss the practical realities of mineral resource classification.

This episode explores current best practices and highlights the importance of combining data-driven methods with geological insight. Whether you're a junior or major, this conversation will help sharpen your classification strategy and confidence levels.

This podcast at a glance:

⏱️ 00:15 – Why resource classification matters across global reporting codes

⏱️ 01:55 – Introduction to the 90-15 approach for confidence-based classification

⏱️ 04:00 – The dangers of the “spotted dog” effect and how to avoid it

⏱️ 05:21 – Calculating drill spacing the smart way: distance-to-holes technique

⏱️ 07:04 – Alternatives to drill spacing: kriging variance and its limitations

⏱️ 08:00 – Why close spacing doesn’t always mean high confidence

⏱️ 09:01 – The two-indicator approach: origins, application, and benefits

⏱️ 13:01 – Assumptions, limitations, and when to adjust the 90-15 rule

⏱️ 17:00 – When the two-indicator method doesn’t fit: deposit-style considerations

⏱️ 18:00 – What’s coming in Part 2: simulation and scorecard approaches

If you would like to contact Ian and Graeme: contact@snowdenoptiro.com

🔔 Subscribe for more Fresh Thinking about the mining industry.

This podcast is also available as a cideo on our Snowden Optiro YouTube channel: https://youtu.be/7CqcvRDi9Jw

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.

Find out more at https://snowdenoptiro.com

Professional Development courses: https://snowdenoptiro.com/professional-development/

contact@snowdenoptiro.com

In this episode of Fresh Thinking by Snowden Optiro, Executive Consultant Ian Glacken interviews Senior Mining Consultant Pedro Ladeira on a topic that’s often overlooked—but critically important: fixed costs in strategic mine planning.

This podcast at a glance:

00:00 – Introduction: Why fixed costs matter in mine planning

01:00 – How variable costs are typically applied in mine plans

02:20 – What are conditional fixed costs and why they matter

03:50 – Impact of fixed costs on strategic planning and scheduling

05:10 – Reclaiming low-grade stockpiles and the role of fixed cost reduction

06:30 – Fixed vs variable costs in processing plants

07:45 – Stockpiling strategy and mine life optimisation

08:50 – When to start accounting for fixed costs in planning

09:30 – Final thoughts: Using fixed costs to optimise your NPV

This is a must-listen for anyone involved in mine planning, financial modelling, or operational strategy.

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

🔔 Subscribe for more Fresh Thinking on mining strategy, geology, and resource optimisation.

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.

Find out more at https://snowdenoptiro.com

https://snowdenoptiro.com/professional-development/

#MinePlanning #MiningStrategy #FixedCosts #NPV #MiningPodcast #SnowdenOptiro #FreshThinking

In this episode of Snowden Optiro's Fresh Thinking podcast, host Pedro Ladeira (Senior Consultant) is joined by Hamish Guthrie (Managing Consultant, Mining Engineering) to explore the critical role of cut-off grades in mining. From defining what a cut-off grade is to explaining how it's applied across different operations and project stages, they discuss the strategic, economic, and technical factors that make this small number a big deal.

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

This Podcast at a Glance

🕒 0:21 – Why cut-off grade is a critical input in mine planning and production

🕒 0:51 – What a cut-off grade is and how it helps define economic inventory

🕒 1:56 – Differences in how cut-off grade is applied in open pit vs. underground mining

🕒 3:34 – How cut-off grades are used at different project stages: resources, planning, daily operations

🕒 4:18 – What goes into calculating a cut-off grade: revenue, cost, taxes, and recoveries

🕒 5:53 – Are cut-off grades fixed? When and why they change over time

🕒 7:00 – The importance of aligning cut-off grade strategy with orebody characteristics

🕒 8:13 – How mining method and processing route influence the cut-off grade

🕒 8:50 – Why cut-off grade is never static — and how operations review it regularly

🕒 9:29 – Final take: the cut-off grade as a key to both short-term gains and long-term sustainability

This video podcast is also available as a free video podcast on Snowden Optiro’s 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.

https://snowdenoptiro.com

https://snowdenoptiro.com/professiona...

contact@snowdenoptiro.com

Discover how Cornwall's rich mining history shaped the global mining industry. In this episode of Fresh Thinking by Snowden Optiro, Executive Consultant Ian Glacken chats with Senior Consultant Laurie Hassall about the legacy of Cornish mining. From tin and copper to tungsten, they explore the region’s innovations, the export of mining expertise worldwide, and what the future holds for mining in Cornwall.

If you'd like to connect with Laurie Hassall and Ian Glacken, please email them: contact@snowdenoptiro.com

This podcast at a glance:
00:00 – Introduction to the episode and guests
00:48 – Why Cornwall became a mining hub and its early beginnings
01:50 – The peak of Cornish mining: key periods and metals
03:53 – Ingenious innovations from Cornish miners (steam engines, safety lamps & more)
05:54 – How Cornish mining practices spread worldwide
06:41 – The social and cultural impact of mining on Cornwall
07:29 – Tungsten’s role in Cornwall’s mining story and Laurie’s direct experience
08:39 – What’s next? The future outlook for mining in Cornwall
10:18 – Final thoughts and reflections

This audio podcast is also available as a free video podcast on Snowden Optiro’s YouTube channel: https://youtube.com/playlist?list=PLZm0zjSNmpo27fX_tfI79Yzhxy3VXjvMt&feature=shared

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.

Snowden Optiro: https://snowdenoptiro.com

Professional Development Courses: https://snowdenoptiro.com/professional-development/

contact@snowdenoptiro.com

Discover how battery electric vehicles (BEVs) are transforming underground mining operations. In this episode of Fresh Thinking by Snowden Optiro, Managing Consultant Hamish Guthrie chats with Principal Consultant Sarah de Vries about the significant safety and health benefits of battery-operated vehicles (BEVs)—improved air quality, lower heat, reduced noise, and less vibration. They also discuss the challenges of transitioning to electric fleets and the future of mine electrification.

This podcast at a glance:

0:00 – Introduction

1:00 – Why are mining companies moving towards BEVs?

1:40 – How BEVs improve underground air quality and OHS

2:45 – Heat reduction: BEVs vs Diesel engines

3:45 – Noise & vibration reductions with BEVs

5:00 – Applications that benefit most from BEVs

5:50 – Challenges of adopting BEVs underground

7:00 – Future of mine electrification

If you'd like to connect with Hamish Guthrie and Sarah de Vries, please email them: contact@snowdenoptiro.com

This video podcast is also available as a free video podcast on 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.

https://snowdenoptiro.com

https://snowdenoptiro.com/professiona...

contact@snowdenoptiro.com

101: Machine Learning – Case Study

In this podcast, Susan Havlin, Managing Consultant APAC and Dr Gregory Zhang, Senior Geology Consultant discuss the application of machine learning for geological domaining in Resource Estimation, with specific reference to a project that Dr Gregory Zhang worked on.

This podcast at a glance:

1.21 A case study using the k-means algorithm

0.55 Why was an alternative approach needed?

2:10 What is the k-means algorithm and why is it suitable?

3:10 What steps were used to apply k-means to the data set?

4:20 What were the key outcomes?

5:20 Any limitations?

7:40 Speed of getting results

8:12 Who can use this method?

If you'd like to connect with Susan Havlin and Dr Gregory Zhang, please email them: contact@snowdenoptiro.com

This audio podcast is also available as a free video podcast on Snowden Optiro’s 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.

https://snowdenoptiro.com

https://snowdenoptiro.com/professiona...

contact@snowdenoptiro.com

In this episode, Ian Glacken our Executive Consultant in Perth, Australia discusses the thorny and divisive topic about whether we should be trying to minimise conditional bias in an estimate or should we be striving for a better idea of grade/tonnage relationship at the time of mining? Ian is joined in this discussion by Graeme Lyall our Executive Consultant who is based in Santiago, and Dr Oscar Rondon, Principal Geostatistician Datamine.

1:26 This podcast video at a glance

3:03 What is conditional bias

4:19 Schools of thought about conditional bias

6:19 The kriging oxymoron

7:00 The least of 2 evils

7:47 Important difference between the 2 schools of thought

8:40 Conditional bias and smoothing

11:42 What is KNA?

15:00 Discrete Gaussian method

Suggested papers to read.

D.G Krige - A practical Analysis of the effects of spatial structure and of data available and accessed, on conditional biases in ordinary kriging.

Quantitative kriging neighbourhood analysis for the mining geologist - A description of the method with worked case examples by J.Vann, S. Jackson and Olivier Bertoli.

If you'd like to connect with Ian, Graeme or Oscar please email them: contact@snowdenoptiro.com

This podcast is also available as a free video podcast on Snowden Optiro’s YouTube channel: https://www.youtube.com/playlist?list=PLZm0zjSNmpo27fX_tfI79Yzhxy3VXjvMt

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 derisk their investments by the provision of quality advice, training and software in the field of Mineral Resources and Mineral/Ore Reserves.

https://snowdenoptiro.com

https://snowdenoptiro.com/professiona...

Email: contact@snowdenoptiro.com

In this episode, Susan Havlin, our Managing Consultant – Geology, and Gregory Zhang, our Senior Geology Consultant, discuss the advantages of developing customised internal tools to tackle technical challenges. They illustrate this with a case study on accurately modeling and managing resource depletion.

This podcast video at a glance:

00:10 Introduction

01:06 Why is it so difficult?

02:18 Errors involved in using the traditional approach

02:45 Applying these methods

03:53 The solution

09:33 Lessons learned

If you'd like to connect with Susan and Gregory, please email them: contact@snowdenoptiro.com

This Fresh Thinking by Snowden Optiro audio podcast is also available as a video podcast on Snowden Optiro's YouTube channel.

These podcasts are for those working in the mining industry. Snowden Optiro - Mining Advisory, Consulting and Professional Development.

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 derisk their investments by the provision of quality advice, training and software in the field of Mineral Resources and Mineral/Ore Reserves.

https://snowdenoptiro.com

https://snowdenoptiro.com/professional-development/

contact@snowdenoptiro.com