Why Mineral Processing Scrubbers Still Wash Through: Thejo Australia & Fortescue WearMon Case Study

Executive Summary: Real-World Tier-1 Validation

A frequent assumption in condition monitoring evaluations is that emerging industrial IoT technologies lack operational proof in harsh, tier-1 processing environments. For S5 System’s WearMon, that proof is already in the field.

WearMon autonomous wireless liner-thickness sensors were commercially procured by Thejo Australia—a premier provider of industrial rubber, polyurethane wear products, and conveyor maintenance services—and installed on three (3) heavy mineral processing scrubbers at Fortescue Metals Group’s (FMG) Solomon Hub in the Pilbara region of Western Australia. An additional commercial contract was deployed on high-wear mineral processing circuits at an Eastern Goldfields gold processing plant in Kalgoorlie, Western Australia.

The Industrial Reality: Confined Space vs. Operational Blind Spots

In mineral processing plants, rotating scrubbers and tumbling drums wash and prepare crushed ore prior to downstream screening, gravity separation, and wet beneficiation. The inner circumference of the drum shell is protected from continuous gouging and abrasive slurry erosion by sacrificial composite rubber and polyurethane wear liner plates.

Managing the integrity of these sacrificial liners historically forced reliability teams into a severe operational compromise:

1. High-Risk Confined Space Entry

Evaluating residual liner thickness traditionally requires stopping the mill, isolating drives, establishing safe atmospheric ventilation, and deploying inspection technicians inside the vessel under hazardous Confined Space Entry (CSE) permits. Technicians use manual ultrasonic thickness (UT) probes or mechanical depth gauges to take single-point spot measurements. Confined space entry exposes personnel to dropped-object, toxic atmospheric, and entrapment hazards.

2. The 6-to-12 Week Blind Operating Window

Between scheduled shutdowns—often spaced 6 to 12 weeks apart—plant reliability engineers operate with zero visibility into liner condition. Variations in ore hardness, unexpected rock fragmentation, or localized plate detachment can cause sudden, accelerated wear. By the time wear becomes noticeable from the outside (through slurry seepage, unusual noise, or excessive vibration), the structural shell may already be breached.

3. Premature Liner Scrap Waste

To mitigate the catastrophic risk of an in-service puncture, maintenance planners routinely replace liner sets conservatively—often discarding liners with 20% to 35% of usable life remaining (typical industry benchmark estimate). Across multiple production lines, this premature replacement represents hundreds of thousands of dollars in wasted liner material and unnecessary shutdown labour.

4. Catastrophic Shell Wash-Through Exposure

If a liner plate fails or detaches undetected, ore slurry directly scours the bare structural steel shell. Within hours, the rotating drum wall is scored, gouged, or pierced. The resulting emergency downtime, hot-work structural welding, and lost throughput routinely total A$250,000 to A$1,200,000+ per incident (industry benchmark estimates based on wet-plant downtime).

Sensor Engineering Architecture: WearMon Flex-PCB Telemetry

WearMon eliminates the inspection blind spot by measuring residual liner thickness continuously from the backside of the wear plate during live drum rotation.

Specification	WearMon Engineering Parameter
Sensing Mechanism	Multi-stage flex-PCB continuous resistance-profiling array
Mounting Profile	Embedded within or mounted flush behind Thejo composite wear plates
Telemetry Protocol	Sub-GHz industrial wireless / LoRaWAN to stationary S5 Gateway
Battery Autonomy	5 to 10 years continuous operation (zero in-field servicing)
Ingress & Ruggedness	IP68 hermetic polyurethane potted compound encapsulation (shock rated to 50g)
Measurement Range	0 to 120 mm residual thickness with ±1 mm resolution

IEC 61511 Functional Safety Framing: Diagnostic Telemetry, Not a SIL Tripping Device

In mission-critical industrial plants governed by IEC 61511 (Functional Safety – Safety Instrumented Systems for the Process Industry Sector), clarity of equipment classification is essential.

WearMon contributes to the plant safety lifecycle through three key architectural mechanisms:

1. Enhancing Diagnostic Coverage (DC): Continuous wear telemetry converts unrevealed dangerous degradation (undetected liner thinning) into revealed diagnostic data, significantly improving overall system diagnostic coverage.
2. Proof-Test Interval Optimization: Under IEC 61511 Clause 16, proof-test frequency dictates the average probability of failure on demand (PFDavg). WearMon provides verified physical evidence of liner condition, allowing maintenance superintendents to optimize inspection intervals and reduce unnecessary high-hazard confined space entries.
3. Clean Architectural Separation: Telemetry feeds directly into plant supervisory control and data acquisition (SCADA/DCS) historians and maintenance planning tools without compromising or complicating safety instrumented system (SIS) trip logic.

Field Verification: Thejo Australia & Fortescue Solomon Hub

The deployment at Fortescue Metals Group’s Solomon Hub in the Pilbara region of Western Australia validated the system under extreme operational conditions:

Operational Parameter	Traditional Manual Inspection	Autonomous WearMon Telemetry
Inspection Access	High-risk confined space entry every 4–8 weeks	Zero confined space entry required for wear tracking
Telemetry Frequency	Periodic single-point snapshot (6–12 wk intervals)	Continuous real-time trend telemetry during live rotation
Failure Protection	Reactive to audible scouring or visible shell leaks	Continuous early multi-threshold alerting
Liner Life Optimization	Liners scrapped with 20–35% life remaining (ind. est.)	Safely run to 5–10% discard threshold (est.)
Shutdown Planning	Rough estimates based on operating run hours	Accurate algorithmic run-out date forecasting

*Note: Quantified figures above reflect engineering projections and industry benchmark estimates. Operational values vary by site throughput.

A secondary commercial contract deployed WearMon on mineral processing circuits at an Eastern Goldfields gold processing plant in Kalgoorlie, WA, confirming that the sensing architecture performs reliably across both iron ore and gold slurry circuits.

Edge Analytics & Run-Out Date Forecasting

WearMon sensor telemetry is processed at the stationary S5 Gateway using proprietary edge analytics:

• Tonnage-Correlated Wear Rates: Real-time tracking of millimeters of wear per thousand tonnes (mm/kt) of ore processed, capturing fluctuations caused by ore hardness changes.
• Predictive Run-Out Forecasting: Automated regression analysis projecting the exact calendar date when residual liner thickness will reach minimum discard thickness.
• Anomaly & Detachment Alerts: Immediate identification of localized impact gouging or abnormal wear patterns indicating liner detachment.

Commercial Procurement & Pilot Evaluation Kits

To support maintenance superintendents and plant reliability engineers evaluating autonomous condition monitoring:

1. OEM & Service Partner Channel: WearMon is available integrated directly into composite wear liners from leading lining manufacturers (Thejo Australia) as pre-instrumented “Smart Liners”.
2. Plant Evaluation Starter Kits: Reliability teams can procure evaluation packages directly via the dedicated product subdomain at wearmon.s5system.com. Evaluation kits include pre-configured sensor nodes, an industrial LoRaWAN gateway, and web dashboard access.

S5 System Pty Ltd | Perth, Western Australia | Web: wearmon.s5system.com | Email: [email protected]