Ep 128: Sampling mistakes that could cost millions

In this episode of Fresh Thinking, Dr Gregory Zhang is joined by Ian Glacken, Executive Consultant at Snowden Optiro, to discuss the crucial role of grade control drilling and modelling. Grade control may seem like a technical detail, but it sits at the very heart of every successful mining operation. From reducing risk and maximising value, to ensuring accurate sampling and modelling, Ian shares insights from decades of experience helping mines achieve better outcomes. Whether you're a geologist, mining engineer, or simply curious about how mines make critical decisions, this episode explains why grade control matters and how to get it right. Key moments: 0:00 – Introduction to the podcast and speakers 1:01 – Why grade control is essential for profitable mining 2:47 – Importance of sampling quality and timing 3:20 – RC drilling vs blast hole drilling: which is best? 4:42 – Underground grade control: diamond drilling and face sampling 6:01 – Common issues with face sampling and how to address them 7:30 – Choosing the right drilling method for your operation 8:27 – How geology influences grade control strategies 8:40 – The JORC Code and reporting requirements for grade control 10:34 – Why grade control isn’t “ground truth” but still vital 12:14 – Final thoughts and takeaways If you would like to contact Ian or Greg: [email protected] Listen on the go: Fresh Thinking is available on all major podcast platforms – subscribe to never miss an episode! Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. Fresh Thinking by Snowden Optiro is rapidly becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries:  training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

Getting your comminution circuit right is critical for the success of any mining project. In this episode of Fresh Thinking, Tarrant Elkington (General Manager, Snowden Optiro) is joined by Dr. Leon Lorenzen (Executive Consultant), who brings over 40 years of experience in processing and plant design. They explore how to design and optimise SAG, ball, and ultrafine grinding circuits, balancing throughput, recovery, and cost to maximise a project’s NPV. What You'll Learn: ⏱ 00:54 – What is comminution and why it matters in mining  ⏱ 02:15 – Typical circuit options: SAG, ball, SABC, IsaMill, HIGmill ⏱ 04:00 – What makes a circuit design “optimal” – technical vs. economic factors ⏱ 05:13 – The impact of grind size on gold recovery and project value ⏱ 07:10 – Life-of-mine considerations for different ore domains ⏱ 08:29 – How Mine-to-Mill blasting strategies affect plant performance ⏱ 10:02 – Examples of comminution circuit design failures and lessons learned ⏱ 12:30 – Final advice for getting comminution design right from the start If you would like to contact either Tarrant or Leon: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. Fresh Thinking by Snowden Optiro is rapidly becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com    contact(at)snowdenoptiro.com

In this episode of the Fresh Thinking podcast, Susan Havlin (Managing Consultant – Geology, APAC) sits down with Dr Gregory Zhang (Senior Consultant - APAC) to explore how mining companies can streamline their resource estimation and grade control workflows. Gregory explains how complex processes can slow teams down, introduce errors, and create “black box” workflows that are difficult to audit. They discuss practical steps for simplifying and optimising workflows, improving collaboration, and ensuring decisions are transparent and data-driven. If you’ve ever struggled with inefficient processes or misclassification in your mineral resource models, this episode is packed with actionable insights to help you get back to focusing on what matters most: the geology. Key Timestamps 0:00 – Introduction to Susan and Greg 0:35 – Why streamlining workflows is critical for mining success 1:45 – Risks of overly complex workflows 2:29 – Key benefits of streamlining: efficiency, quality, collaboration 3:44 – Preventing misclassification with streamlined workflows 4:32 – How errors impact resource models and reserves 5:16 – Practical steps to start streamlining your processes 6:18 – Keeping workflows lean, transparent, and adaptable 6:34 – Final thoughts and closing remarks If you would like to contact Greg or Susan: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. Fresh Thinking by Snowden Optiro is rapidly becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

Small errors in sampling can lead to big consequences in mining. In this second episode of our three-part series on sampling, Mark Murphy (Manager Geological Services, IGO) and Ian Glacken (Executive Consultant, Snowden Optiro) explore the different types of sampling errors - and how to recognise, minimise, and prevent them.  From unavoidable “correct” errors to preventable “incorrect” errors, they share real-world insights into why understanding sampling is critical for both technical teams and decision-makers.  Whether you're a geologist, mining engineer, or manager, this episode will make you rethink how you approach sampling in your operations. ⏱ Timestamps: 0:08 – Introducing the types of sampling errors 1:11 – What is fundamental sampling error? 3:33 – Grouping and segregation error explained 7:29 – Why most errors happen early in the sampling process 8:38 – Understanding “incorrect” errors and how to avoid them 12:29 – The role of clear procedures and duplicate sampling 14:50 – Why spatial understanding of duplicates matters 15:56 – Replicates vs duplicates: getting the terminology right If you would like to contact Ian or Mark: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. Fresh Thinking by Snowden Optiro is rapidly becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

Join Tarrant Elkington, General Manager of Snowden Optiro, and Scott Carpenter, Director of Technology at Datamine Software, as they explore the rapidly evolving world of artificial intelligence in mining. In this episode of Fresh Thinking, they discuss:  The parallels between AI and other disruptive technologies like autonomous haulage. How to navigate the hype cycle and spot real opportunities amidst the noise. The difference between generative AI and agentic AI and what each means for the mining industry. Why human intuition and expertise remain essential in a data-driven future. Whether you’re curious about the future of digital mining or want to understand where AI is headed, this conversation offers practical insights and thought-provoking ideas. Key Time Stamps 00:00 – Introduction and guest background. 01:18 – Setting the stage: AI as the next disruptive technology in mining. 05:14 – Understanding the hype cycle and Amara’s Law. 10:06 – Lessons from autonomous haulage systems and parallels to AI adoption. 12:02 – The adjacent possible principle: multiple technologies combining to drive change. 17:05 – Where AI sits in the hype cycle today. 20:01 – Generative AI vs. Agentic AI: key differences and future impact. 24:55 – Why quality data and human expertise are still crucial. 33:21 – Looking ahead: where AI could take resource modelling and mine planning. 37:42 – Closing thoughts and reflections on AI’s future in mining. If you would like to contact Tarrant and Scott: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. Fresh Thinking by Snowden Optiro is rapidly becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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.  Datamine is a software solutions business that enables those in the mining industry to confidently make effective strategic, tactical and operational decisions at all stages of the mining process. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

In this episode of the Fresh Thinking podcast, Laurie Hassall (Senior Consultant, Geology) and Senzeni Matondi (Principal Consultant, Geology) from Snowden Optiro's UK office explore the fascinating world of silica sands. Often overlooked, silica sands are vital for producing glass, solar panels, and high-tech products that shape our modern world. Laurie and Senzeni discuss what makes silica sands so unique, how they are processed, and why demand for this industrial mineral is growing. Whether you work in mining, processing, or downstream industries, this episode provides valuable insights into how silica sands are transforming from a bulk commodity into a critical mineral for the future. Key Timestamps 0:00 – Introduction to the hosts and today’s topic 0:48 – What silica sands are and why they matter 2:00 – What sets silica apart from other industrial minerals 3:10 – Purity levels and the critical role of Fe₂O₃ in glass production 5:01 – Key factors for processing silica sands 5:35 – Typical processing pathway explained 7:25 – Resource estimation for silica sand deposits 9:43 – Why silica sands are now seen as a critical mineral 10:38 – The future of silica sands: geometallurgy and sustainability 12:01 – Final thoughts and takeaways Have a question about silica sands or you'd like to contact Laurie and Senzeni: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. Fresh Thinking by Snowden Optiro is rapidly becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

In 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: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. 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/ Fresh Thinking by Snowden Optiro is becoming the best mining podcast globally - you can find our podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

Stochastic Mine Planning – Evolving the Way We Manage Uncertainty In this episode, Tarrant Elkington (General Manager, Snowden Optiro) is joined by Matheus Faria (Director of Technical Services, KPI Mining) to explore the evolving role of stochastic mine planning. Stochastic approaches move beyond conventional “single-input” mine plans by explicitly considering uncertainty in key parameters such as block models, recoveries, and prices. Tarrant and Matheus discuss how this approach can transform decision-making and create more resilient mine plans. Key moments in the episode: [00:02] – What stochastic mine planning is and why it’s gaining traction. [07:45] – Limitations of conventional deterministic planning. [16:20] – Applying stochastic methods to sequencing, cut-off grades, stockpiling, and blending. [27:50] – Practical insights from Matheus on integrating stochastic planning into operations. [39:10] – Looking ahead: the future of stochastic planning in the mining industry. [43:30] – Discussion on the real-world challenges of adoption, including computational demands and the need for organisational buy-in. [50:05] – Reflections on how stochastic planning supports better communication between technical teams and decision-makers. [55:40] – Final thoughts from both Tarrant and Matheus on where the industry is heading and advice for companies considering stochastic approaches. This episode offers valuable insights for mining professionals interested in risk management, decision-making, and the future of strategic mine planning. Have a question or want to get in touch? Contact us: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. You can find our Fresh Thinking by Snowden Optiro podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. Snowden Optiro: 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. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com KPI Mining Solutions: KPI Mining Solutions provide significant value by developing and commercializing cutting-edge software and services to the mining industry. They bring innovative stochastic mine planning and orebody modeling solutions to the mining industry, transforming their entire operation.. Their strength comes from 20 plus years of experience in data and analytics, artificial intelligence, digital experience, and enterprise performance management. They build custom and commercial software solutions and offer consulting services across a wide range of use cases in mining, supply chain, manufacturing and transportation. Inquiries: https://kpimining.com/about-us/

In this first of three episodes on sampling, Ian Glacken (Executive Consultant at Snowden Optiro) speaks with Mark Murphy (Manager of Geological Services at IGO), about why sampling is one of the most critical – yet often under-taught – skills in geology. From gold to base metals, exploration to mine geology, Mark shares four decades of experience on how sampling impacts decision-making, project economics, and geological understanding. This podcast at a glance:  00:00 – Introduction to Mark Murphy and the 3-part series 01:02 – Why sampling is vital for geologists 03:36 – Lessons from gold mining and coarse gold challenges 05:49 – How sampling principles apply across all commodities 07:38 – Key differences between exploration and mine geologists 10:33 – Precision, accuracy, and representativity in grade control 13:52 – Advice for young geologists to build sampling skills Keep tuned for Parts 2 and 3 of this Sampling series. Have a question or want to get in touch? Contact us: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. LINK to Snowden Optiro Professional Development courses - Look for the Sampling Theory and Best Practice course: https://snowdenoptiro.com/professional-development/ You can find our Fresh Thinking by Snowden Optiro podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com contact(at)snowdenoptiro.com

In this episode, Julian Aldridge (Managing Consultant, EMEAA) joins Laurie Hassell (Senior Consultant, UK) to discuss the complexities of nickel laterite deposits - from geology to geometallurgy and the processing challenges posed by magnesium and free silica. With more than 20 years’ experience in resource geology, Julian brings practical insight into how geological variability affects processing decisions, cost, and mine planning. Key Points & Timestamps: 00:34 – What is a nickel laterite deposit? 01:03 – The role of mafic and ultramafic rocks 01:30 – Laterite vs saprolite horizons 02:10 – Why geometallurgy is critical for processing 03:07 – The impact of magnesium and free silica 04:38 – HPAL vs pyrometallurgical processing routes 05:35 – How free silica dilutes grade and increases OPEX 06:30 – The importance of early-stage planning and blending Have a question or want to get in touch? Contact us: [email protected] Explore more: https://snowdenoptiro.com/ 👍 Like, comment, and subscribe for more technical mining insights from our global consulting team. You can find our Fresh Thinking by Snowden Optiro podcasts on YouTube, Spotify, Apple Podcasts and most other podcast platforms. 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. For training or consulting enquiries: training(at)snowdenoptiro.com  contact(at)snowdenoptiro.com  #NickelLaterite #Geometallurgy #MiningPodcast #SnowdenOptiro #FreshThinking