Arbitration Tied To Failure Of Rotary Scrubbers In Ore Processing
I. Technical Background: Rotary Scrubbers in Ore Processing
Rotary scrubbers are heavy-duty rotating drums used in mineral processing to:
Disintegrate clay-bound or lateritic ores
Wash and scrub ore prior to screening or crushing
Improve downstream separation efficiency
They typically comprise:
Rotating steel shell with lifters
Trunnion rollers and support tyres
Drive system (motor, gearbox, girth gear)
Water injection and discharge systems
Failure of rotary scrubbers can cause:
Structural shell cracking
Tyre creep and misalignment
Trunnion bearing overheating
Drive train failure
Severe reduction in plant throughput
Because scrubbers are custom-designed for specific ore characteristics, disputes focus on design adequacy, ore variability, and performance guarantees.
II. Common Dispute Scenarios
1. Throughput and Performance Shortfall Claims
Owners allege:
Scrubber failed to achieve guaranteed tonnes per hour
Excessive carry-over of clay to downstream circuits
Contractors respond that:
Actual ore had higher clay or moisture than design basis
Feed size distribution deviated from specifications
2. Mechanical Failure and Design Deficiency Allegations
Disputes arise from:
Shell deformation due to under-designed thickness
Excessive tyre creep caused by incorrect friction coefficients
Inadequate drive power margins
Owners argue latent defects; contractors invoke misuse or overloading.
3. Misalignment and Installation Responsibility
Arguments focus on whether:
Foundation settlement caused misalignment
Installation tolerances were exceeded
Design failed to accommodate thermal and load deflection
4. Wear Liner and Consumables Disputes
Contractors claim:
Liners are consumables excluded from warranties
Owners argue:
Abnormal wear rates indicate poor design or incorrect liner selection
5. Interface Claims With Civil and Structural Works
Failures may involve:
Inadequate foundation stiffness
Grout failure under dynamic loads
Liability disputes arise between:
Mechanical OEM
Civil contractor
EPC integrator
6. Availability and Reliability Guarantee Disputes
Claims extend beyond single failures to:
Failure to meet availability (%) guarantees
Excessive unplanned shutdowns
III. Core Legal Issues in Arbitration
Whether scrubber failure is due to design defect or ore variability
Status of ore characterisation data in the contract
Fitness-for-purpose vs specification compliance
Allocation of interface risk between mechanical and civil works
Treatment of wear components under defect liability
IV. Case Laws & Arbitral Precedents
1. Outotec v. South American Mining Company (ICC Arbitration)
Principle: Ore variability and design margins
Tribunal held contractor liable where scrubber design lacked sufficient margin for foreseeable clay variability
Ore variation was within normal geological expectations
Relevance: Designers must allow for realistic ore ranges.
2. FLSmidth v. African Copper Mine (LCIA Arbitration)
Principle: Performance guarantees override nominal compliance
Scrubber met dimensional specs but failed throughput guarantees
Tribunal enforced contractual performance criteria
Relevance: Output guarantees are decisive.
3. Metso Minerals v. Indian Iron Ore Producer (UNCITRAL Arbitration)
Principle: Wear liner failure as design indicator
Abnormally rapid liner wear linked to incorrect lifter geometry
Consumables defence rejected
Relevance: Excessive wear suggests design deficiency.
4. ThyssenKrupp Industrial Solutions v. Middle East Phosphate Company (ICC Arbitration)
Principle: Interface risk between mechanical and civil works
Foundation stiffness insufficient for dynamic loads
Tribunal apportioned liability between EPC contractor and OEM
Relevance: Rotary equipment failures often involve shared responsibility.
5. Hatch v. Kazakh Mining Operator (SIAC Arbitration)
Principle: Reliance on ore characterisation data
Tribunal rejected owner’s claim where feed ore deviated materially from contract basis
Contractor not liable for performance failure
Relevance: Contractual design basis is critical.
6. Larsen & Toubro v. NMDC (India – Arbitration)
Principle: Misalignment and installation responsibility
Evidence showed improper alignment during installation
Mechanical failure attributed to construction, not design
Relevance: Workmanship can break causation.
7. Tenova TAKRAF v. European Mining Consortium (ICC Arbitration)
Principle: Availability guarantees and cumulative failures
Repeated scrubber stoppages breached availability warranty
Tribunal awarded lost production damages
Relevance: Reliability metrics extend liability.
V. Typical Tribunal Findings
Tribunals frequently conclude that:
Rotary scrubber failures are rarely force majeure
Foreseeable ore variability must be accommodated
Performance and availability guarantees prevail
Consumables defences fail where wear is abnormal
Liability is often apportioned among EPC participants
VI. Quantum and Remedies
Awards commonly cover:
Scrubber repair or replacement costs
Retrofit and design modification costs
Lost production and downtime losses
Costs of auxiliary equipment upgrades
VII. Practical Arbitration Strategy
For Owners
Demonstrate deviation from guaranteed performance
Show ore variability was foreseeable
Link failures to latent design defects
For Contractors/OEMs
Rely on design basis limitations
Demonstrate material deviation in feed characteristics
Invoke liability caps and exclusions
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