Zero Unplanned Maintenance: A Copper Plant Transformation
Through a WARMAN® pump upgrade engineered to improve reliability in critical slurry circuits. The solution reduced maintenance risk, enabling more predictable performance and uninterrupted operation.
The challenge
The mine’s mill circuit is central to its operations - but it was also a source of escalating maintenance costs and unplanned downtime.
1. Frequent maintenance due to short wear life
The impeller and throatbush in the competitor’s pump lasted only 700 hours, while the liners delivered less than 1,400 hours.
2. No standby pump in a critical service application
With no standby pump available in this Service Class 5 application, any maintenance event or unplanned stoppage immediately put mill operations at risk.
3. Downtime directly impacting throughput, productivity and cost
The competitor’s SAG-ball mill discharge pump in Mill 2 became too costly to operate due to the short wear life of its spare parts. Frequent maintenance was significantly increasing both operating costs and production disruptions, reducing throughput and overall plant productivity.
How the solution was implemented
Weir has partnered with the customer on multiple pump upgrades over several years, systematically improving wear life and reducing operating costs. Previous upgrades included:
Phase 1: Upgrade smaller WARMAN® pumps in Plant 1
An upgrade of the SAG transfer circuit by replacing legacy units with WARMAN® MCU® 250 pumps, optimising system design and modifying discharge piping to improve reliability. They then completed the conversion across the circuit and introduced Hyperchrome® A61 alloy, further extending wear life by 40% and increasing maintenance intervals from 2,000 to 2,800 hours.
Phase 2: Upgrade to rubber-lined WARMAN® MCR® mill pumps in Plant 1
Weir assessed the application, recommended WARMAN® MCR® rubber-lined pumps, and engineered a customised bolt-in solution using 3D scans to eliminate on-site rework and enable changeout within a single shift. By replacing six pumps, Weir delivered a step-change in performance - extending liner life by 6.3x and impeller life by 2.5x, achieving US$490k in savings, and outperforming all competing elastomer-lined options.
Latest project: Replace the SAG-ball mill pump in Plant 2
With confidence in Weir’s solutions proven in Phases 1 and 2, the plant team moved to replace the competitor’s SAG-ball mill discharge pump in Plant 2, operating without a standby pump (Service Class 5).
Why this solution worked
1. Safe maintenance design
Weir began with a 3D scan of the site to assess space and fitment. The 3D scanning demonstrated that there was sufficient front-end clearance for the removal of the impeller with a lifting jig. Weir designed customised lifting tools to ensure the equipment could be safely and efficiently maintained in-situ.
2. Retrofit practicality
To overcome the differences in piping, Weir installed a new discharge elbow to allow for a smooth transition to the existing discharge header.
3. Pump-specific selection
Weir carried out hydraulic and technical analysis to select the optimal pump to service both SAG and ball mill discharge and specified a rubber-lined WARMAN® MCR® 650 mill pump. Its high-resilience elastomer lining handles fine to coarse particles and can be worn down fully before replacement, offering both cost and safety advantages.
Operational results
During a planned maintenance shutdown, the miner replaced the SAG-ball mill discharge pump. Weir’s thorough engineering preparation ensured the installation was completed ahead of schedule.
1. Up to +471% improved wear life
The WARMAN® MCR® 650 pump installed in Service Class 5 application (severe duty, no standby pump) increased wear life by 205% for the impeller and 471% for the liners.
2. Greatly reduced mill downtime
The miner purchased a spare set of casings, which they use during maintenance.
Commercial impact
1. $1.1million cost saving
Switching to the WARMAN® MCR® mill pump significantly reduced the miner’s parts costs, labour costs, downtime costs and inventory costs, all of which delivered significant annual TCO savings of 40%*.
2. 3% energy saving
The WARMAN® MCR® 650 pump improved hydraulic efficiency in the SAG/ball mill circuit by better matching duty conditions and reducing recirculation and internal losses.
3. Zero unplanned maintenance
The robust design and engineered fit delivered reliable, stable operation, eliminating unexpected failures and unplanned pump maintenance in the circuit.
4. Reduced costs of replacement parts
Liner wear life improved by +471%, significantly reducing the frequency of liner replacements and lowering replacement part costs.
5. Increase in maintenance intervals
Impeller wear life improved by +205%, extending operating periods between maintenance events and reducing downtime.
All performance results, cost savings, wear life figures and other outcomes described in this email are internal estimates based on Weir’s view of comparable installations. They are provided for illustrative purposes only, results are not guaranteed, and actual performance may vary according to specific site conditions and circumstances.
Weir Minerals Africa,
+27 (0) 87 720 0260,
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