There are numerous developments globally that combine analytics with advanced technologies to enhance the effectiveness of maintenance solutions, complementing the broader trend of mines moving away from one-off cost reductions and employing sustainable cost-management programmes that improve total cost of ownership.
“It is impossible to sustainably reduce the costs of maintenance simply by examin- ing component costs. By using analytics, companies can assess the costs of an entire process and identify exceptions where remedial action is required,” says integrated solutions provider Takraf Africa – part of the global Tenova Takraf group – client support services GM Paul Davies.
Technologies that provide continuous, real-time information on the activity and state of equipment can improve decision- making, while other systems can transport data from a huge range of disparate sources to deliver on-demand reports, enabling miners to improve equipment use and promote reliability, thereby, reducing associated downtime.
Further, global pressures to reduce mining’s impact on the environment and South Africa’s power crisis highlight the need for environment-friendly and power efficient maintenance activities, which should be complemented by ensuring that equipment is operating in accordance with design specifications.
“Only properly maintained equipment is environment friendly and energy efficient,” Davies points out.
Takraf Africa offers refurbishment and upgrade services to enhance energy efficiency and render equipment more environment friendly than the original design, using and incorporating the latest technological advancements.
For example, the Bradford Breaker, which is distributed by Takraf Africa in South Africa under licence to Terrasource Global, is testament to how equipment is retrofitted to accommodate incremental improvements to technologies to provide increased performance, greater energy efficiency and reduced maintenance requirements and downtime.
“The high percentage of contamination in the breaker feed, typical of the South African coal application, resulted in an unacceptable wear rate using the conventional breaker drum design,” he explains.
Davies outlines that the limited open area of the traditional round apertures was a further issue. As a result, the screen plate of the redesigned breaker drum is manufactured from thicker fabricated square grid-type screen plates to provide increased wear life and a more than 40% open area for the same aperture size.
Breakers in operation on South African coal mines have been retrofitted with this redesigned drum to facilitate the simultaneous sizing and cleaning of coal.
Takraf Africa has carried out 13 such breaker drum replacements since 2007.
Committed to Innovation
“New maintenance approaches and methods are demanded by the rapid pace of mechanisation and automation in the mining industry. Therefore, there has been increased focus on the mine maintenance function in the last 20 years,” notes Davies.
The capital outlay and ownership costs of mining equipment and its importance to production requires that it is maintained in a good condition to ensure the most effective performance and best return on investment, as well as high safety and energy efficiency levels, while limiting the impact on the environment.
Takraf Africa emphasises that its commitment to innovative and improved maintenance methods begins at the very start of the equipment’s life cycle, when the equipment is engineered for robust operation and minimal and simplified maintenance.
For example, besides being efficient collectors of the high dust loads typical of ore processing applications, Tenova dynamic scrubbers are designed to limit energy and maintenance requirements, as well as water consumption, making them well suited for the remote and arid mining conditions found in much of Africa.
Davies says the biggest challenge pertaining to mining maintenance is the depressed mineral resources market, as capital is constrained.
“While this has meant a greater demand for refurbishment and maintenance, with clients seeking to sweat their assets, it can, in some instances, also result in clients skipping routine but necessary maintenance.”
In addition, junior miners, now more prevalent in the market, may not have the available capital to keep up to date with mine equipment and site maintenance.
This cost-containment drive has also resulted in some mines making use of nonoriginal-equipment manufacturer components and spares in an effort to cut costs.
Although these mines try to implement condition-monitoring systems to provide early warning signs of imminent failures, Takraf Africa emphasises that original- equipment manufacturer (OEM) spares are important to ensure that the conditions of machines are maintained at a high level.
“OEM spares are fabricated to high standards and, therefore, provide a longer service life and a higher level of machine availability, which, in the long term, make them the more cost-effective route,” Davies highlights.
Maintenance methods and schedules are equipment specific and, therefore, maintenance plans must be customised to suit the equipment’s requirements, taking account of the operating conditions.
“There is no general rule regarding the reassessment of methods and schedules, but monitoring and ongoing evaluation of equipment condition plays a crucial role in proactively identifying poor performance and the need for remedial action,” asserts Davies.
In addition, monitoring and evaluation enable the mine to assess the effectiveness and applicability of the maintenance methods and schedules being applied to improve maintenance task lists in line with site-specific requirements, based on well recorded facts.
Such monitoring and technical evaluation must make use of scientifically developed procedures, fault tracking and the recording of critical operating parameters.
“As per the OEM’s recommended schedule, maintenance is a non-negotiable aspect when optimising equipment performance, decreasing downtimes and boosting equipment life,” Davies concludes.