This is the strong opinion expressed by Andrew Evans, industrial lubricants marketing manager at Shell Lubricants South Africa, who believes that the changing needs of the coal mining industry are placing the spotlight on effective lubricant management to help maintain productivity

“Over the past three years – with the soaring price of coal and the resulting pressure on operators to increase output – effective lubrication has become more important than ever,” he says. “The challenge to lubricant suppliers has been to address the sector’s changing needs with on-the-ground technical support, ancillary services and targeted product development,” he adds.

“The rising price of coal is great news for the coal mining industry and has led to increased investment,” explains Evans “but essentially it means that operators are using the same equipment to produce coal at a much more intensive rate.

“Equipment utilisation, reliability and availability are key factors in gaining optimum operating hours between service intervals, which put extra pressure on the lubricant to perform. It is also prompting operators to try to run machinery for longer without a service break,” Evans continues.

Lubricant1

With soaring coal prices and the resulting pressure on operators to increase output,
effective lubrication of operations like these have become a major challenge to lubricant suppliers

Shell Lubricants SA has discovered that many coal mine operators are now attempting to increase certain component life from 16 000 to 20 000 hours. “A 25% increase in the working life of components is an extremely ambitious target and, where achievable, can have significant cost benefits,” Evans claims. “However, it also carries considerable risks, including component failure and oil break down. Either of these scenarios can result in unscheduled and expensive production stoppages and losses that may outweigh the financial gain of extending component life, increasing rebuild intervals and driving greater throughput,” he contends.

In addition to achieving production efficiencies by driving component life to its limits, operators are also trying to maximise production rates by extending service intervals and, therefore, extending oil drain intervals, according to Evans. “On the face of it, extending oil drain intervals can help achieve significant production efficiencies as it reduces stoppages,” he comments, However, it also increases the risk factors. The lubricant is required to work harder and longer to protect components over a longer time period, so its effectiveness will decline, just as the need for effective lubrication of components increases. Unless the right lubricant is used and carefully monitored, the end result can be unscheduled stoppages – just the opposite of what the operator is trying to achieve.

“As one of the essential elements of equipment efficiency, effective lubrication management must be factored into production efficiency programmes, and more and more mine operators are calling on the expertise of their lubricant supplier to help them achieve their output goals,” Evans reveals.

Lubricant2

In the coal industry, equipment utilisation,
reliability and availability are key
factors in gaining optimum operating
hours – day or night

The first step in pushing equipment longer and harder to increase productivity is to ensure the lubricants used have the high performance capabilities to cope with more intense production levels. Shell Lubricants has developed a range of high performance lubricants to perform in harsh operating conditions. “Lubricants such as Shell Omala – a range of mineral and synthetic gear oils, and Shell Malleus – a range of open gear lubricants, offer excellent performance properties,” he claims, “and both lubricants offer high thermal stability, excellent adhesiveness at high temperatures and resistance to rusting and corrosion.”

In addition, Shell Lubricants offers a range of greases that perform in a variety of applications and conditions, from slow speed pins and bushes, to high speed bearings and extremely loaded open gears. Evans comments: “Many of Shell’s high performance oils and greases are specifically designed to cope with the intensive production targets that mine operators are adopting, offering extended lubrication intervals, improved component life and increased equipment availability. This means that operators can viably extend component life and increase service intervals to help reduce both scheduled and unscheduled stoppages.”

Operators should also ensure that their choice of product addresses any specific operating requirements they may face. In territories where equipment is exposed to extremes of temperatures, specialist lubricants may be required during some periods as these will further help to protect components so that high production levels can be maintained.

Even with a high quality lubricant, the risks of extending oil drain and service intervals and increasing component life are high if the lubricant’s effectiveness is not carefully and regularly monitored. “Oil Condition Monitoring (OCM) not only allows the operator to identify any shortcomings in the lubricant’s efficiency, it can pinpoint any abnormal trending or wear rates, giving the operator an indication of whether he may be pushing his equipment too hard,” Evans explains.

Lubricant3

Even at dawn the coal
industry is hard at work

OCM involves the analysis of oil samples taken at specific points in the equipment at regular intervals to monitor changes in the lubricant that could indicate current or potential problems. “When studied by Shell Lubricants experts, the condition of the oil, the pace of its deterioration and the presence of contaminants can all provide indicators of equipment performance,” he points out. “This analysis can be used to provide a simple traffic light status of the equipment’s condition and recommendations of what preventative action needs to be taken and when.”

Implementing an OCM regime allows operators to pick up potential problems early enough to schedule maintenance before unplanned stoppages and reactive maintenance is required.

Results of OCM analysis provide the operator with risk alert; allowing him to know whether the lubricant and equipment are working effectively, and alerting him to a potential problem by highlighting an existing issue that must be addressed immediately.

For as long as operators can benefit from the high demand for coal by increasing production levels, the question of how to drive productivity without damaging profitability through unnecessary reactive maintenance will continue to challenge the industry.

“There is no single answer to how intensively a mine can produce before it runs into problems, as every site is different,” says Evans. “However, for operators that understand the vital role that lubricants can play in both enhancing equipment efficiency and revealing potential faults, lubrication can play an important role in managing the risks of extending component life, and increasing service and oil drain intervals,” he concludes.