While coal remains South Africa’s staple energy source for the foreseeable future, the coal mining industry is facing an uncertain period, with ores grades depreciating significantly, exacerbated by low coal prices and the general low appetite to fund new coal plants. In the face of these struggles, Frengelina Mabotja, senior metallurgist and capital sales engineer at Kwatani, tells Modern Mining that process equipment has a huge influence in coal mines’ drive for ongoing cost reduction and increased productivity to mine profitably.
Notwithstanding South Africa’s aim to reach net zero emissions by 2050, the country’s energy plan still anticipates a continued major role for coal. Currently, more than 90% of South Africa’s energy is generated from coal, mainly mined and burned in the north-east by state-owned power provider, Eskom. South Africa’s coal mining landscape is driven largely by its domestic market and remains responsible for sustaining a significant chunk of the country’s energy requirements.
Most of the coal supply, says Frengelina Mabotja, senior metallurgist and capital sales engineer at Kwatani, is currently from a handful of major mining houses. In recent years, she says, Eskom started moving away from the traditional cost-plus models in its quest to develop and support the junior miners market with black ownership, resulting in a rise of junior coal players.
“Kwatani has over the years partnered with both majors and junior miners, utilising our expertise to provide customised cost-effective, fit-for-purpose processing solutions to suit both parties’ needs. We work across the coal mining spectrum and are equipped to understand the specific needs of both the majors and juniors and engineer solutions which cater to individual specific needs,” explains Mabotja.
For this reason, Kwatani offers two distinct equipment ranges tailored to each party’s specific requirements and capital budget. The requirements can vary significantly between a junior, small scale miner and a long-life major i.e. operating lifespan, tonnage throughput, efficiency and yield require- ments as well as type/size of product needed, among other parameters.
The industry, according to Mabotja, indicates that the conditions that will be encountered in future coal mines will undoubtedly differ from the current ones, as the more easily mined coal has already been processed. As seams with greater amounts of overburden are mined, she says, surface mining will potentially become much more expensive.
“The coal industry is currently enduring low coal prices with a recovery in the short term very unlikely.
Additionally, the appetite for funding of new coal plants and expansions is low, resulting in signifi- cant uncertainty in the sector. Consequently, there is a strong drive for continuous cost reduction and increased productivity across majors, juniors and the industry at large,” says Mabotja.
Apart from the initial capital expenditure, she says, processing equipment at mines has an enormous influence on production efficiency, tonnage and operating costs. With that in mind, Kwatani offers long-lasting, robust vibrating screens and feeders designed for continuous tonnage and high efficiency, which reduces the processing cost per ton and the overall cost of running the machine over its lifetime.
“There have been few changes in mining and processing of coarse coal in recent years. Although some of the old technologies are still being used, we have over the years seen increased demand for high-capacity equipment for small to fines coal processing, with banana ‘high capacity’ screens commonly preferred in that application,” she says.
Given that screening equipment is a critical compo- nent of any coal plant, and as such can be the cause of unscheduled and costly plant shutdown if failures occur, regular maintenance is essential to prevent this.
With its holistic approach, through collective processes and mechanical expertise, Kwatani continues to successfully offer and implement tailored value adding models to coal mines in South Africa. The approach is to pay attention to the complete process. That, coupled with the company’s customised engineering design, results in equipment robustness, longevity and safe operation, which is always a priority.
In the current environment, major coal miners are typically looking for large-scale equipment to boost efficiencies and high tonnage throughputs, she says. “Kwatani offers a comprehensive, customised range that includes some large, high capacity screens, for example, the 4,3-m wide banana screen which is well suited to this requirement.”
Kwatanis’s engineering team places a major focus on optimising the structural integrity, weight distribution and lifespan of the equipment. The OEM’s screens can therefore process high tonnages in heavy duty applications, while delivering high efficiency.
“We consider various factors that affect the fatigue life of the screen in order to provide a dura- ble, robust, long-lasting and high performing unit. We have supplied a large number of screening machines, with the majority of them currently oper- ating at some of the largest opencast coal mining operations in the world,” she says.
Kwatani’s brute force grizzly feeders for run-of- mine (ROM) operations are capable of sizing and feeding material from high drop heights, operating at up to 2 000 tph. “Furthermore, we ensure that we engineer our equipment to seamlessly fit into the existing structures, avoiding the need to make costly changes to given infrastructure,” says Mabotja.
The junior coal sector, she adds, operates at the opposite end of the scale and typically requires smaller-scale, modular plants processing up to 250 tph, incorporating smaller screening equipment below 2,4 m in width.
“We have a dedicated product range which is tailored to the budget and needs of these process- ing plants. Because junior miners often need to start generating revenue as quickly as possible, they operate not only on very tight budgets, but also short delivery times which we are able to accommodate with our dedicated floor space and jobbing system needed for this product range,” says Mabotja.
Major coal miners benefit from Kwatani’s customised service level agreements, which include: continuous audits at given time intervals to measure the performance and condition of the equipment; on- site training from artisans through to supervisors; on-going operating and maintenance training; on-site stockholding management; refurbishment programmes; as well as cost per ton agreements where Kwatani is fully responsible for equipment operations, replacements, refurbishments and maintenance.
“These agreements are structured so that we share in the gains and losses of the mine. We get paid only when the mine is producing according to expectations. For this reason, we have a full team on site, daily to ensure that the screens are always in top shape and any issues are resolved imminently,” she says.
Junior mining houses may not require such extensive service level agreements but do however need regular visits and quick turnaround times on service calls to ensure they remain operational for as much time as possible. Kwatani’s experienced service team serves this sector of the market and offers financially flexible options to suit clients’ budgets.
Some customers are challenged by a lack of skilled personnel or stretched resources. Mine personnel are often
required to maintain entire processing plants, from building infrastructure to crushers and screens. Kwatani’s service offering assists with maintenance prediction, using the company’s latest condition monitoring technology. Out of this involvement in the lifecycle of the equipment, the company also gets to identify future design improvements to continually drive lower total cost of ownership on its custom engineered equipment.
Additionally, Kwatani’s in-house research and development enables the company to complete specific application test work and back its process simulations and engineering designs, to improve efficiency and increase throughput.
Kwatani has over the past 44 years established a successful equipment reference base and track record across the country’s major coal mines. The company has also made a significant entry into the junior mining side of the coal sector, and has positioned itself as a screen supplier of choice for this group of customers.
“Our operating mantra – engineered for tonnage ensures that each coal customer is provided with a customised, fit-for-purpose solution that is robust and durable, delivered to the required operating efficiency at the required tonnage, while reducing the overall cost of operation,” she says.
In conclusion, Mabotja says the significance of new developments is continuously discussed and shared on the Southern African Coal Processing Society platforms, thus offering OEMs insights into the needs of coal miners. “The emphasis is not only to offer a piece of vibrating equipment, but also to stay abreast of market trends with a product offering that is in line with the ever-changing market demands,” she concludes.