In this interview, AZoMaterials speaks with Garry Noble, Senior Product Applications Specialist at Thermo Fisher Scientific, about the capabilities of Prompt Gamma Neutron Activation Analysis (PGNAA), its evolution, and its powerful applications across industries such as coal, cement, steel, and copper mining.
Can you please introduce yourself and your role at Thermo Fisher Scientific?
My name is Garry Noble, and I’m the Senior Product Applications Specialist at Thermo Fisher Scientific. My background is in physics, and I’ve been working with PGNAA technology for more than 25 years. I focus on elemental analysis solutions for process industries, helping customers understand and apply PGNAA effectively across various sectors like cement, coal, steel, and mining.
What exactly is PGNAA, and how does it work?
PGNAA stands for Prompt Gamma Neutron Activation Analysis. It’s an elemental analysis technique where a neutron source irradiates the sample material. The nuclei in the sample absorb these neutrons and emit prompt gamma rays. By detecting these gamma rays, we can identify and quantify the elements present in the material.
Unlike surface-based methods like XRF, PGNAA is a bulk measurement technique. Neutrons and the resulting gamma rays penetrate deep into the material, allowing real-time, through-the-belt analysis of large volumes – regardless of particle size or density. This makes it incredibly valuable for continuous process control.
How did PGNAA first become established in the coal industry?
PGNAA’s adoption in coal started in the 1980s, and I’ve seen it evolve firsthand. It’s a key tool in blending and sorting applications. For example, power plants use PGNAA to blend high- and low-sulfur coal in real time to meet emission targets. Coal preparation plants use PGNAA to accurately sort and then blend high- and low-ash coal, to meet a target specification. The ability to measure and respond in real time was a game changer.
PGNAA has become standard in cement manufacturing. How did that transformation happen?
When I commissioned my first PGNAA analyzer in a cement plant in 2000, it was almost an afterthought. Today, it’s designed into new plant layouts from the beginning. Cement producers now rely on PGNAA for quarry control, blending stockpiles, and additive dosing to ensure consistent kiln feed.
The technology allows operators to manage limestone variability more effectively, extend the life of quarries, reduce costly additives, and improve energy efficiency in the kiln. It has become a standard process control tool in the cement industry.
PGNAA is also being used in steelmaking, particularly in sinter plants. Can you explain that application?
Yes, in integrated steel plants, sinter is a key feed to the blast furnace. Controlling the calcium-to-silica ratio, or basicity, is critical. PGNAA enables real-time monitoring and control of this ratio by measuring iron ore fines and limestone on the conveyor belt before sintering. It replaces delayed lab analyses with instant data, reducing variability by half and improving furnace efficiency.
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How is PGNAA being adopted in the copper mining sector?
Copper is a newer frontier for PGNAA, and the potential is huge. Unlike the key elements in coal or cement, copper grades are low – often below 1% – so the analyzer design must be more sensitive. We’ve installed systems at sites like Red Chris in Canada, where PGNAA is measuring variability truck-by-truck and even within individual loads.
This provides insight into misrouting, validates mine plans, and offers feed-forward control to the mill and flotation circuits. It’s not just analysis – it’s operational intelligence.
Sampling can be a big challenge in mining. How does PGNAA help solve this?
Traditional grab sampling methods offer a snapshot. PGNAA, by contrast, provides a continuous video of your process. It measures the entire conveyor belt cross-section, accounting for variability in real time. This is crucial when you’re dealing with high tonnage or coarse particle sizes, where representative sampling is difficult.
It removes guesswork and enables you to act on what’s actually happening, not what you think is happening based on a few samples.
What role does calibration play in PGNAA’s performance?
Calibration is everything. At Thermo Fisher, we perform robust factory calibrations tailored to each site’s specific ore characteristics. We model the expected elemental ranges and include variables like belt loading.
Trying to calibrate in the field with real ore is time-consuming, inconsistent, and costly. Our approach ensures the analyzer is ready from day one, speeding up adoption and maximizing value.
From Rock to Results: Real-Time Insights with PGNAA
Where do you see PGNAA going in the future?
Although PGNAA has been around for 40 years, we’re just scratching the surface in terms of its potential – especially in mining. Beyond current applications, it can support bulk ore sorting, predict rock hardness, assess tailings for acid generation potential, and optimize leaching processes.
The real breakthrough will come when plants are designed with PGNAA in mind, not as an add-on. Just like how it became integral to cement manufacturing, I believe copper and other mining sectors will follow suit.
What final message would you give to industries not yet using PGNAA?
PGNAA is a mature, proven technology with a track record across multiple industries. If you have variability in your process – and most operations do – PGNAA gives you the power to measure, control, and optimize. It’s time to have the conversation and explore how this technology can transform your operations.
About Garry Noble
Garry Noble is a Senior Product Applications Specialist at Thermo Fisher Scientific with over 25 years of expertise in Prompt Gamma Neutron Activation Analysis (PGNAA). He holds a degree in physics and has become a global authority in applying PGNAA across industries including coal, cement, steel, and mining. Garry has been instrumental in the evolution of PGNAA from a niche technology to an industry standard, particularly in cement production and process control. He has worked hands-on with calibrations, analyzer commissioning, and integration into process control systems across more than 20 different commodities. Garry continues to drive the adoption of real-time elemental analysis technologies that improve efficiency, product quality, and
resource management in heavy industry.
This information has been sourced, reviewed and adapted from materials provided by Thermo Fisher Scientific – Production Process & Analytics.
For more information on this source, please visit Thermo Fisher Scientific – Production Process & Analytics.
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