Mining and mineral processing operations rely on the uninterrupted operation of samplers and centrifuges to maintain product quality and process efficiency.
Samplers collect representative samples that are accurate and reproducible, while centrifuges enable effective solid-liquid separation, dewatering, and classification within a process plant.
Despite their importance within the mineral processing value chain, maintenance of these electromechanical systems is often carried out reactively rather than in a proactive manner. This can lead to inaccurate sampling, unexpected failures, and costly operational downtime.
To better manage this, Multotec’s proactive maintenance approach helps customers extend the lifespan of their equipment, monitor wear rates and supports overall plant performance with the aim of achieving the best possible life cycle cost from the installed equipment.
Samplers and centrifuges operate under highly demanding conditions where extreme temperatures and corrosive or abrasive material can place strain on equipment. Centrifuges are exposed to high flow velocities, abrasive materials, and significant G-forces, while sampler cutter blades pass through process streams of abrasive materials, which contribute to wear on equipment components over time.
“Under the operational pressures of the mining industry, maintenance is often ignored when equipment appears to be functioning normally, only receiving attention once failures occur, by which point it is too late,” explains Gerrit du Plessis, Product Specialist for Solid-Liquid Separation at Multotec.
Centrifuges, typically installed at the end of metallurgical or chemical process streams for dewatering, play a direct role in the availability of upstream production lines, while samplers, designed to collect representative portions of mineral streams for analysis, are expected to operate with up to 99.95% accuracy.
“In a typical 56-shift production month, losing just one sampling shift due to a minor breakdown or equipment unavailability means that nearly two percent of the stream goes unsampled, which directly impacts overall sampling accuracy,” said Willem Slabbert, Specialist for Sampling and Magnetics at Multotec.
He adds that proactive, lifecycle-focused maintenance strategies are critical in all mining and industrial settings to sustaining consistent equipment reliability.
To prevent unplanned breakdowns, equipment must be engineered to perform reliably under demanding conditions and be supported by proactive monitoring and predictive maintenance programmes to maintain high levels of equipment availability.
Maintaining equipment longevity and availability requires a structured and proactive maintenance approach. Best practice includes on-site inspections to assess equipment condition, monitoring wear on critical components to better anticipate and schedule replacements.
“By implementing regular condition monitoring and predictive maintenance interventions, early signs of mechanical issues can be identified and addressed before they escalate,” Slabbert said.
Despite the clear benefits, mining operations often face practical challenges in keeping samplers and centrifuges performing optimally. These include the temptation to defer maintenance, running of equipment out of specification, limited on-site technical expertise of specialised equipment, and spare parts shortages that can delay critical repairs and replacement.
“There is a tendency on plants to do what is urgent and not do what is important,” Slabbert points out. Proactive maintenance, which is important, is not done as regularly as tending to an equipment failure, which is regarded as urgent. “A proactive maintenance strategy, which includes predictive maintenance and well-managed spare parts inventories, help mitigate risk and ensure consistent equipment performance,” Slabbert notes.
Importantly, the long-term reliability of samplers and centrifuges goes beyond the initial supply of equipment. “Tailored service-level agreements and structured field-service and technical support programmes from equipment suppliers enable more effective maintenance planning, faster issue identification, and timely resolution,” du Plessis notes.
Multotec’s experienced field-service technicians work closely with customers to maximise equipment life cycle, given the specialised skills required for effective maintenance of centrifuges and samplers. “The company conducts regular site visits and check-ins with maintenance staff to ensure that daily, weekly or monthly maintenance checks are completed, ensure that monthly and quarterly maintenance activities are undertaken, and to plan for monthly, quarterly or bi-annual maintenance shutdowns,” du Plessis explains. “Support also extends to maintenance staff training if required and guidance on critical stock and spare part holding.”
Moreover, Multotec’s operating and maintenance manuals, which are underpinned by the company’s application knowledge, technical expertise and understanding of process flow sheets, provide a best practice guideline for clients to get the most out of their equipment.
“When these practices are followed, equipment can operate reliably for over 20 years, while poor maintenance can lead to catastrophic failures in as little as 18 months if operating conditions are not monitored and maintenance is not undertaken,” said Slabbert.