Here’s your 3-minute quick read of Fresh Thinking by Snowden Optiro’s podcast Episode 107.
We’ve pulled out the key insights and takeaways – perfect for when you want the value, minus the headphones.

Why Refractory Gold Matters – And What You Can Do About It

Fresh Thinking Podcast Summary with Dr Leon Lorenzen and Dr Tarrant Elkington

Refractory gold ores are increasingly common in modern mining – and they come with a unique set of technical and financial challenges. In this episode of Fresh Thinking, Snowden Optiro’s General Manager Dr Tarrant Elkington is joined by Metallurgic Engineer Dr Leon Lorenzen to unpack what makes a gold ore “refractory” and how miners can navigate the complex processing pathways required.

What is Refractory Gold?

In simple terms, refractory gold can’t be recovered using standard processing techniques. While free-milling ores allow gold to be extracted via simple grinding and leaching, refractory ores contain gold that’s locked within other minerals – commonly sulfides like pyrite and pyrrhotite, or within carbonaceous material. These conditions reduce gold recovery significantly, often below 80%, sometimes even as low as 50%.

According to Leon, anything less than 90% recovery is a red flag, and the lower the recovery, the more refractory the ore is considered to be. The problem isn’t just technical – it’s economic. Poor recoveries impact project viability, and tackling the issue requires serious capital and operating expenditure.

Early Detection is Key

So when should miners be looking out for signs of refractory ore? The earlier, the better. As Leon explains, indicators are often picked up during early exploration and domain modelling. If lithology points to sulfide-rich zones or complex mineral associations, it’s worth conducting metallurgical test work early to avoid costly surprises later.

Choosing the Right Processing Method

Once you’ve confirmed refractory gold, selecting the right processing pathway is crucial. There are five common approaches:

• Pressure Oxidation (POX) – Highly effective but capital-intensive.
• Albion Process – Suitable for specific mineralogies but space- and water-intensive.
• BIOX® – Great for breaking down arsenopyrite; biologically driven and energy efficient.
• Ultrafine Grinding – Can be effective when gold is not tightly locked, but raises energy costs.
• Roasting – Less common due to environmental concerns but still used where viable.

Each method comes with its own blend of energy, safety, reagent, and infrastructure implications. The right choice depends on the ore’s mineralogy, site location, and overall project economics.

The Bigger Picture

Refractory processing plants are still relatively rare, but Leon predicts we’ll see more of them—particularly centralised hubs servicing multiple mines. Smaller-scale projects will need to weigh the cost of building new facilities against the benefits of outsourcing or partnering.

Major operations such as Lihir and Siguiri have proven that with the right strategy, refractory ore can be processed effectively and profitably. But as Leon reminds us, this space is littered with past failures -highlighting the need for careful evaluation, sound financial modelling, and early planning.

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Listen to the full episode to hear more insights on the future of refractory processing and why this topic should be top of mind for mining companies and investors alike.

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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 Leon: 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