The role of condition monitoring in optimising performance and safety in the mining sector

Mining reserves in South Africa are vast. According to statistics from the South African Department of Mineral Resources and the US Geological Survey our ore reserves amount to a value of more than US$2.5 trillion [1]. Conversely the industry is in crisis – why? Costs have become prohibitive, primarily due to years of lack of development in R&D, causing the industry to reduce its international competitiveness and no longer be an innovator on the forefront of new industrialisation opportunities.

Safety also plays a role in this arena. Although the number of fatal injuries has reduced by limiting reactive or unplanned maintenance, and further decreasing the likelihood of safety hazards, 58 deaths still occurred in 2020 [2].

Let us unpack how effective condition monitoring can work towards ameliorating this somewhat dire situation.

Mining in particular is fraught with unreliability due to mechanical haulage with extensive wear on equipment, and the best way to improve the reliability of a mine is with effective condition monitoring. Condition monitoring more than any other maintenance tactic can optimise your maintenance strategy whether you take an online, offline or intime condition monitoring approach.

With mining in particular the scale of economy in downtime is huge – moving the ore from the pit to the crushers to the end product – if any one of those stages breaks down the resulting financial loss is vast. For example, if a furnace transformer at a mine is off for one day losses can be calculated at up to R2.5M per day.

In addition, the synergistic roles of condition monitoring and safety in the mining sector cannot be underestimated. Condition monitoring consultant Tom Dalton says: “Safety often drives condition monitoring – human life or limbs are not replaceable. The condition of plant can have far reaching consequences in terms of safety. Consider the scenario at a deep mine hauling up to 30 people in the cage. Not only is it crucial to have condition monitoring technology on the cable to ensure it is within serviceable limits, we also need to consider the hidden reliability risks – if the cable should snap and the brakes (a hidden failure) failed, the results could be catastrophic. Thus, we can see that condition monitoring in our mining sector needs to consider multiple systems need to ensure optimal safety.”

Let us now consider the condition monitoring technologies which can be put in place with relative ease of implementation to improve both safety and ROI.

One of the original and stalwart pillars of condition monitoring is vibration analysis. This is a simple yet effective way to detect faulty components through placing accelerometers in strategic positions on the asset to be analysed to measure the vibration of the system. Vibration analysis utilises displacement, velocity and acceleration time waveforms (TWF), or the fast fourier transform (FFT) of the TWF to accurately detect faulty components.

“People don’t understand how easy these are to implement.” – Tom Dalton, Condition Monitoring Consultant

Another technology which should be considered on assets where early failure detection is especially important, is that of ultrasonic analysis. This technology can be used to detect sound abnormalities in electrical systems (eg corona, tracking, arcing); mechanical systems (eg drive belts, couplings, bearings) and tightness integrity (eg marine, chemical, medical).

Condition monitoring allows us to detect potential failures across all systems well in advance, allowing for proper planning, thereby improving the reliability of a mine and improving safety for the workforce. Simply put – condition monitoring allows us to increase uptime and decrease downtime.

Condition-based maintenance is applied when the deterioration in asset health or performance is detectable, or there is adequate warning time to react. (PF interval is large enough, HSSE issues are addressed and it is cost-effective).

Condition monitoring provides an accurate asset health diagnosis, which leads to preventive actions being taken as soon as potential failure is detected.

There is no equivalent to the P-F curve and for this reason performance is often overlooked. The consequences of unacceptable performance over the long term can be more costly than functional failure, which is quickly rectified.

Whilst these technologies can be readily implemented, there are hurdles to overcome. In this industry one of the biggest obstacles which we face today is the lack of training. Condition monitoring consultant Tom Dalton asserts this with the statement that: “There is lack of knowledge – people don’t understand the technology or they feel the technology is too expensive. Avoidance of proper succession planning also plays a role where the technology knowledge lies with only one person in the organisation. Organisations need to ensure that sufficient resources are trained in the technology.”

A further observance is that an organisation may have implemented the appropriate condition monitoring technologies, but fail to react on the information it provides. Essentially, it all comes down to trained and skilled resources implementing effective of condition monitoring in the system.

With all of these factors to consider – how do we move to the forefront of industry, ensure workforce safety and from a global standpoint, remain competitive?

The advent of IIoT is upon us and to remain relevant in this arena we need to consider migrating our condition monitoring technologies to being intime, to remain relevant in this highly competitive global market. We cannot underestimate and consider the impact of what intime condition monitoring can bring to the ROI of our plant, as well as improved workforce efficiency and safety.

“We have to look at the optimal state we want our plant to be in – you need to determine your plant’s strategic path,” says conditioning monitoring consultant Tom Dalton. “Our reliability engineers are best equipped to determine the most cost-effective savings – yes – some may take years to realise – but we need to consider the that condition monitoring today is about extracting value, the role of technology and the integration with asset management. They are key to a sustainable benefit for the ROI of your plant and your workforce safety. These are the factors we need to consider in condition monitoring today.”

Statistics referenced/cited in the article
[1] The South African mining sector – Wits University
[2] South Africa: Mining industry fatalities 2020 | Statista