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As the global mining industry scales up to meet the rising demand for critical minerals, the size and power of SAG mills have grown significantly—often exceeding 40 feet in diameter and 28 megawatts of installed capacity.
With this scale-up comes a host of new challenges: heavier liner loads, increased reline risks, complex wear patterns, and spiralling energy costs. At the heart of it all lies the mill liner—the interface that defines productivity, reliability, and safety.
Traditional liners are no longer enough. That’s why Tega Industries developed the DynaPrime® Combination Liner—an innovative, high-performance solution engineered specifically for 40ft+ SAG mills.
The Evolution of SAG Mills – Why Bigger Isn’t Always Better
The 21st century ushered in the era of mega-grinding mills. The first 40ft SAG mill was installed as part of the Cadia project, followed by longer 40ft mills operating at 28 MW of power. Then, in 2010, a 42ft mill was selected for the Conga Project, signalling the next leap in size—though it remains uninstalled.
Today, with declining ore grades and the drive to improve circuit efficiency, mining operations are increasingly asking:
“Can we push mill size and power even further to optimise our flowsheets?”
The answer is yes—but it comes with new design stresses and liner performance demands. It is no longer just about bigger—it’s about smarter.
Customer Challenges in Large SAG Mills
Through extensive field experience and customer interactions, Tega has identified four key challenges that repeatedly limit performance in large-diameter SAG mills:
1. Heavier Conventional Liners Limit Charge Levels & Delay Ramp-Up
Traditional steel-based liners significantly increase mill weight, restricting the maximum charge volume. This limitation:
- Reduces grinding efficiency
- Slows mill ramp-up after relines
- Directly impacts throughput and productivity
Customers often face delays in reaching nameplate capacity, losing valuable production time during the early phase of each campaign.
2. Reliability Issues: Liner Cracking & Unplanned Shutdowns
In large SAG mills, impact forces and liner stress are magnified. Many conventional liners suffer from:
- Cracking or structural failure
- Loosening and movement
- Early replacement needs
These failures often trigger unplanned shutdowns, resulting in lost revenue and compromised operational stability.
3. Relining Large Mills: Key Safety Challenges
Relining large grinding mills presents significant safety challenges, particularly when handling heavy liners under time-sensitive shutdown conditions. The following are two major safety risks associated with conventional reline procedures:
- Confined Space Risks: Traditional mill reline operations require personnel to work inside the mill, which classifies as a high-risk confined space. This environment significantly increases the potential for accidents due to limited access, restricted ventilation, and difficulties in emergency evacuation.
- Health and Fire Hazards: In many cases, oxy-fuel cutting is used to remove worn liners. This method produces hazardous fumes that pose serious health risks to workers.
These conditions significantly elevate the risk of injury, illness, and delays, underscoring the need for safer and automated reline practices.
4. High Energy Cost per Tonne of Ore Processed
When liner design is suboptimal, energy transfer from the mill to the charge becomes inefficient, leading to:
- Higher specific energy consumption
- Reduced ore breakage efficiency
- Increased carbon footprint per tonne milled
In today’s mining economics, every kilowatt-hour matters.
How DynaPrime® Delivers on Every Front
1. Built for Performance: Engineered to Last Longer
DynaPrime® is a next-generation composite liner system that combines the best properties of rubber and steel, purpose-built for the demands of high-capacity SAG mills.
- Rubber layers absorb impact energy and dampen vibration → No cracking or structural failures
- Alloy inserts provide abrasion resistance in high-wear zones → Reduced wear rates and extended service life
- Tailored geometry ensures even wear and charge movement → Predictable wear patterns and better process control
The result:
- Longer liner life
- Improved charge lift and grinding efficiency
- Enhanced shell protection—even under continuous loads of up to 28 MW
With DynaPrime®, you're not just extending wear life—you’re upgrading mill performance at every rotation.
2. Designed for Safety and Speed: Reimagining the Reline
DynaPrime® is engineered with an outside-fixing design, eliminating the need for internal bolting and significantly reducing safety risks during relining.
- Reduced liner weight and modular design → Fewer components to handle and install
- Fewer pieces per row with precision-engineered fitment → Faster, safer relines with minimal adjustments
- Optimised media trajectory and liner profile → Controlled energy transfer
The result:
- Shorter and safer reline durations
- Lower human risk exposure during installation
- Quicker ramp-up for improved availability
With DynaPrime®, relines are no longer a bottleneck—they are a strategic enabler for higher mill productivity and operational safety.
3. A Smart Investment: Lower Operating Costs
DynaPrime® delivers measurable value beyond wear life—it’s a total cost reduction solution for your grinding operation.
- Extended reline intervals → Reduced downtime and maintenance costs
- Lower energy consumption per tonne → Improved energy efficiency and reduced OPEX
- Consistent wear performance → Predictable uptime and reliable production planning
The result:
- Fewer shutdowns and greater mill availability
- Lower cost per tonne processed
- More stable and efficient operations
With DynaPrime®, you are not just investing in a liner—you are investing in a smarter, more profitable milling operation.
DynaPrime® isn’t just meeting today’s standards—it’s shaping the future of mill lining performance.
The Future of SAG Mill Lining Starts Here
The future of mining lies in larger, more efficient grinding circuits. But that future demands a rethink of every component inside the mill.
The DynaPrime® Combination Liner is purpose-built for the next generation of 40ft+ SAG mills—designed to reduce downtime, enhance reliability, and maximise every kilowatt and tonne.
Is your liner holding you back—or pushing you forward?
With DynaPrime®, the answer is clear.
Let’s Talk Performance
Curious how DynaPrime® can transform your mill’s efficiency, safety, and cost profile?
Contact our experts today and take the first step towards smarter, stronger mill lining.
