It’s no secret that mining and processing are tough businesses, physically and financially. Operational efficiency under severe conditions is vital to profitability. Demands on “critical path” equipment, such as open-gear systems, are increasing as operational environments become more severe and efficiency requirements escalate.

Choosing the proper greases and lubricants for mechanical systems is vital. Surprisingly, only 40 percent of the companies surveyed have lubrication policies and procedures in place, and only 34 percent turn to their lubrication suppliers as a technical resource. This may be in part because 44 percent of the companies claimed all lubricants and greases deliver the same performance, and only 53 percent believed that lubricant choice affects reliability.

Only 53 percent believe choosing higher quality lubricants will reduce maintenance costs.

“Even though lubricant purchases are a small part of the maintenance budget, effective lubrication can have a measurable impact,” says Greg Morris, a Shell grease production application specialist. “If you do it well, you can see the benefits. If you do it poorly, operational expenses can be higher than necessary.”

Increasing equipment demands

As mining operations go farther and deeper, conditions become more extreme, increasing the demands on lubricants. Ambient temperatures, for example, can range from -50° Celsius (-58° Fahrenheit) to as high as 55°C to 60°C (131° to 140° F). Mining equipment manufacturers recognize that equipment specifications that worked under more moderate conditions may not be effective in these new locations and severe conditions.

“The products and procedures that have historically worked will not necessarily work effectively in the future,” Morris says. “Customers and their equipment must endure tougher conditions, so we must provide improved, high-performance lubricants. The customers, the conditions and the original equipment manufacturers demand it.”

In developing these high-performance open gear lubricants, several areas must be considered:

• Viscosity
• Base oil selection
• Thickener effects
• Load carrying capacity
• Mobility

Stating the performance needs of open gear grease is much easier than achieving them. Mine operators must weigh issues of performance against cost, mobility, manufacturing consistency and availability.

Poor adhesiveness results in unprotected open gear tooth surfaces. On left: Shell Gadus S4 OGT on open gear teeth of an electric shovel. On right: Competitor product on an electric shovel at same site.

Performance expectations and reality

Making matters even more difficult is the changing scale of mining machinery, and how it is used. Some mobile equipment, such as large electric shovels, have gearing that is undersized for the loads they are now expected to handle. Combined with narrower alignment adjustment limits, this can result in overloading, lubricant film failure, and in turn, gearing failure.

Stating the performance needs of open gear grease is much easier than achieving them.

Similarly, the rush to provide more viscous fluids and greases has opened the door to enhanced performance but has introduced mobility concerns. “Mine operators can purchase the perfectly designed lubricant and still have equipment issues if you cannot get the product to where it needs to go,” says Justin Gardner, a Shell lube services expert.

Balancing these concerns is critical for a company determining the best lubricants for its open gear systems.

From reactive to proactive

While product formulation, delivery and information are all essential, one of the most important factors for improving performance and reliability of open gear systems is routine inspections, which should be an integral part of all maintenance programs. New gearing can be damaged because of avoidable problems, such as failing to supply the lubricant to the gearing. In fact, 60 percent of failures can be linked to improper lubrication.

“You need to shift from being reactive to proactive,” Morris says. “You have to manage and proactively monitor these critical gear systems to help you get the performance and protection you need.”

The role of the lubricant supplier

An effective maintenance program is based on choosing products that are designed for the mine operators’ needs, as well as implementing procedures and engineering services that help identify potential problems and areas for improvement.

“At Shell, we understand that open-gear lubrication is difficult and also critical to operational efficiency," Morris says. "We have developed products and validated their field performance. These products are designed to enhance the efficiency and reliability of both fixed and mobile open-gear systems. Our specialists are trained to design and review maintenance programs and offer ideas for improvement to help reduce costs and boost reliability.”

Greg Morris, Shell Grease Product Application Specialist in the Americas, has worked in industrial lubricants since 1998, in multiple roles within Shell, supporting both the commercial and technical community.

Visit lube-education.com/mining for the latest industry insights from Shell. Please direct all inquiries about Shell Lubricants to Cassie Hackstedt at Cassie.Hackstedt@shell.com.

Pit & Quarry Direct provides professionals in the aggregate mining industry with insights on timely innovations in equipment and technology. This newsletter was produced by North Coast Media’s content marketing staff in collaboration with Shell Lubricants.