How an Aussie mining company saved more than $166,631 through an oil change

A synthetic gearbox oil was the key to this gold miner saving over $160,000 a year.

Based in the Australian outback, this global gold miner's semi-autogenous grinding (SAG) mill operates in a dusty, hot and humid environment. The harsh conditions can impact the efficiency of any machinery, so the company pays particular attention to maximising energy savings.

The goldmine, based in Western Australia, is critical to achieving production targets, which means reliable operation and minimal downtime are vital.

In 2014, the company's reliability assurance team began exploring options for reducing electricity consumption while extending the life of their equipment without necessitating major engineering changes.

Two years on, the team are starting to see the fruits of their labour, having generated annual savings of $166,631.

How did they do it?

The site was subject to an audit by Shell – now Viva Energy’s – technical advisors.* They identified that the Falk gearbox, driven by a 2.5MW Toshiba motor, could deliver a potential cost saving to the gold miner.

The team used motor current draw to measure power consumption, along with multiple thermocouples to track gearbox temperatures. The SAG mill went through regular oil inspections to monitor oil quality, and existing databases were used to track the life of the equipment.

After all this, the technical advisors came up with a simple solution – an oil change.

They identified that synthetic gear oils could reduce frictional losses and help to extend oil and equipment life.

It was recommended that the gold miner replace its Shell Omala S2 G 320 oil with the Shell Omala S4 GX 320 for the SAG mill and other gearboxes on site.

Shell Omala S4 GX is an advanced, synthetic heavy-duty industrial gear oil offering excellent lubrication performance under severe operating conditions, including reduced friction, long service life and high resistance to micropitting.

It is made by combining advanced additives with synthetic base fluids to help provide resistance to breakdown over long-duration and/or high-temperature operation. The oil can operate successfully at temperatures up to 120°C. It offers the potential to significantly extend service intervals compared with conventional industrial gear oils.

The product can help to maintain or enhance the efficiency of industrial gear systems through improved low-temperature performance and lower friction compared with mineral oil-based products. This provides better lubrication at low start-up temperatures. Shell Omala S4 GX oil has excellent load carrying capabilities to reduce wear which helps to extend the life of the gears and ensure efficient lubrication of the contact areas.

The results

Since the change, the gold miner has achieved two per cent annual energy savings, a doubling of oil drain intervals, a reduction in average operating temperature of 8°C and a 50 per cent increase in gearbox life. Since 2014, the gold miner has achieved $166,631 in annual cash savings. Of these savings, $65,755 is due to the two per cent reduction in electricity consumption (based on their electricity rates at the time).

The importance of technical support

The technical support and advice that the lubricant industry offers can be vital for achieving cost savings.

Viva Energy employs a team of local fuel and lubricant engineers who provide support across a range of industries. If required, Viva Energy technical experts can go out to work in the field with customers, as exemplified in this case study, conducting detailed analyses of equipment and site.

Assistance may be in the form of recommendations for lubricants for different equipment, field lubricant surveys, grease audits, training, cost-saving initiative projects or running extension of oil drain intervals. There are also additional services such as LubeAnalyst, an oil-condition monitoring service.

All savings amounts were converted from USD to AUD based on the exchange rate as at 13 September 2016.

*Shell's Australian downstream operating entity, The Shell Company of Australia Limited converted to "Viva Energy Australia Pty Ltd" in 2014.