When a new plant is being planned, considerable care needs to be taken in the design and placement of the transfer chutes, argues Mark Baller, managing director of Weba Chute Systems.
“In our experience, there has been considerable disruption caused to plant operations by transfer chutes which are not optimally designed or properly located in the flowsheet,” says Baller. “This is a concern, as this disruption can cause financial loss that is not commensurate with the value of the equipment.”
Conveyor feeding material to a Weba cascade head chute.
He says the relatively low cost of a chute compared to the high value items like crushers and screens may be one reason why they are not taken as seriously as they should be. For example, the chute supplier is often engaged quite late in the plant design process.
“The plant layout has then already been decided, and the chutes are just expected to be slotted in as and where the space is available,” he says. “We request our clients to talk to us earlier, so that we can give the necessary valuable input on where chutes would be best placed. It is costly and time consuming to try and adjust plant designs further down the line.”
Conveyor feeding material to a Weba cascade head chute.
It is even more costly to make changes after the plant is built and is then found to experience challenges at the transfer points. This may even require complex modifications such as moving the head pulley or changing structures and flows to allow for a different flow path.
“Nonetheless, we have developed a reputation for success even in these difficult situations,” he says. “We helped an Australian iron ore mine which was having to shut its plant down every six weeks due to problems with its transfer chutes.”
The mine needed to extend its chute maintenance window from six to eight weeks, so Weba Chute Systems engineered a solution for their challenging ore – which was sticky when wet. This was achieved, with maintenance interval in fact being lengthened from six to 12 weeks.
“Our improvements meant that the transfer chutes were lasting longer than the other equipment, and were no longer an obstacle in the mine’s strategy to reduce the number of shutdowns each year,” he says.
Eskom’s Kendal power station near Ogies is having its ash disposal facility (ADF) expanded in a multi-faceted contract by joint venture partners Concor and Lubocon Civils.
The project, says Concor contracts manager Pierre van Vuuren, will ensure that the new ash disposal facility is environmentally compliant with South Africa’s environmental regulations. The continuous ADF will store the ash generated by Kendal until 2032.
Existing ash dump facility (left) separated by v-drains and access road from the farm dam (right).Finalising the construction of silt trap 1 adjacent to the ash dump’s water channels.Constructing the pollution control dam which comprises two separate compartments – one on either side of the access road.
“At the centre of the project is the lined ADF, which will ensure that there is no contamination of groundwater,” says Van Vuuren. “The various infrastructure elements of this contract all make sure that polluted water is kept separate from clean water, and that water can be recycled to reduce consumption.”
The new ADF is being constructed on a 65 hectare footprint adjacent to the existing ADF, which is reaching the end of its operational life. The design includes a subsoil drainage system which allows clean groundwater to run into a clean water dam.
“An impermeable liner is placed over the subsoil drainage system, while another drainage system is installed above the liner,” he says. “The upper system allows water contaminated by ash to be channelled to the pollution control dam – from where it can be used for dust suppression.”
The clean water is also channelled to a dedicated dam, and is returned to the power station for re-use. Constructing the new ADF has also required the diversion of an existing natural stream, leading to a new 3 km man made channel being built.
“The stream diversion will withstand a 1-in-100-year flood, and has been lined with hand-filled gabion baskets to prevent erosion,” he says. “The 30 m wide stream contains over 4,100 gabion baskets, each measuring 1 m high, 1 m wide and 3 m long.”
To complete this mammoth task, about 120 workers were involved over a period of 19 months – packing 42,000 t of gabion rock into the wire baskets. More than 2000 Reno mattresses were also used.
The project has employed hundreds of local residents and sourced extensively from local suppliers. It has also trained people in a range of construction-related skills, adding significantly to the skills base in the region.
The Murray & Roberts Cementation shaft sinking team responsible for delivering a new ventilation shaft at Palabora Copper Mine (PMC) recently celebrated the achievement of a major milestone – the reaching of the 800 m mark. This represents two-thirds of the shaft’s final depth of 1 200 m.
The ventilation shaft forms part of the copper producer’s Lift II project which will extend mine life by more than 15 years. Originally an open pit mine, the Palabora mine transitioned to being an underground block cave operation in the early 2000s when Lift 1 was commissioned.
PMC is located within Phalaborwa in the Limpopo province in South Africa and the extension of the life of mine will increase shareholders’ value and sustain jobs and livelihoods of the surrounding communities. The mine has also initiated several wildlife management programmes to minimise the impact of its operations on the environment as well as promote the harmonious co-existence of people, industry and wildlife.
A view showing the location of the ventilation shaft project at PMC. Concrete lining of the 8.5 m diameter ventilation shaft. A full kibble being hoisted during lashing operations.An excavator busy lashing at the shaft bottom with shaft lining being carried out on the face.
Murray & Roberts Cementation’s contract to sink the 8.5 m diameter shaft was awarded in February 2019. According to Fred Durand, the company’s senior project manager, the shaft sinking is currently making good progress, with 40 or more lined metres of advance being completed on average each month.
“Shaft sinking operations should be completed by the end of this year with final handover of the shaft to our client, PMC, taking place at the end of the first quarter of 2024,” he says.
Ground conditions have presented a challenge on the project. This has resulted in the shaft lining being taken right down to the blasted face, says Jas Malherbe, Murray & Roberts Cementation’s on-site project manager.
“Normally, we would line the shaft to within 12 to 18 m of shaft bottom and support the sidewalls temporarily with split sets and mesh,” he explains. “In practice, this did not prove viable, prompting us to change our approach. The method we’ve adopted is unconventional but has proven to be highly effective.”
Drilling is undertaken by two twin-boom Komatsu electro-hydraulic jumbo drill rigs. These are slung down the shaft from surface and nested in the four-deck stage for drilling the shaft bottom, a procedure which is repeated for each 48-hour blast-to-blast cycle.
Another key piece of equipment is a Komatsu excavator with a 0.3 m3 bucket. It is lowered from surface through the stage to shaft bottom and is used for lashing. All the waste rock is loaded into a 11 tonne kibble which transports it to surface.
The ground conditions at the shaft are such that blasting tends to produce large rocks, which can be difficult to handle. “We break these up using the excavator which has a quick coupler which allows it be fitted with a hydraulic breaker within a few minutes,” says Malherbe.
The methods being used at Palabora are based on the Canadian shaft-sinking method that Murray & Roberts Cementation has pioneered in South Africa at its Venetia mine contract for De Beers Group.
“We have adapted the method because of the very different conditions we’re facing but many elements remain the same or are very similar,” says Malherbe. “In particular, the high degree of safety offered by the Canadian method has not in any way been compromised.”
The number of Murray & Roberts Cementation personnel deployed per shift is 25. The total labour complement on site is currently just over 120 people, 46 % of them recruited from local communities.
Murray & Roberts Cementation has a vigorous CSI programme running in conjunction with its contract. The programme is being implemented in close association with PMC and has mainly focused on supporting local schools in the Phalaborwa area with infrastructure such as ablution facilities, fences, water storage tanks and boreholes.
“In addition, we have trained nearly 80 youths from local communities at our Bentley Park Training Academy near Carletonville,” says Durand. “Another 20 are currently undergoing training. This programme is giving them skills which are in high demand in mining and which could lead to them securing permanent employment within the mining industry.”
As mining projects look to optimise their pump and process performance while minimising risk, there is good reason why Weir Minerals Africa is regularly awarded the lion’s share of large execution projects.
According to Marnus Koorts, general manager pump products at Weir Minerals Africa, the company wins about 95% of the process projects in the mining sector today for which it bids.
“Our success has everything to do with how we leverage our full design, engineering and manufacturing capability,” says Koorts. “This level of expertise and infrastructure is something that few of our competitors can match; indeed, we are the only pump manufacturer in Africa with this integrated resource base.”
He adds that most of its product offering is manufactured in-house. This internal capability gives the business a distinct advantage in developing and implementing custom designs and complex solutions. It also provides closer control over quality and can radically improve lead times.
“An important differentiator for us is our two foundries – our Heavy Bay Foundry in Gqeberha and another in Isando which includes our innovative Replicast plant,” he says. “These two facilities give us greater reliability in our supply chain and scheduling, reducing the risk of late deliveries that could delay customers’ project roll out.”
With Weir Minerals Africa’s large team of hydraulic engineers, there is also considerable in-country capacity to support engineered-to-order (ETO) requirements. This enhances the value of early stage collaboration with customers, where the company can offer insights and guidance on pump and process related issues even at concept stage. This, emphasises Koorts, makes it easier for project managers to pre-empt technical challenges later.
The world class facility in Isando is one of Weir Minerals’ technology hubs for a range of its pump brands including the Warman DWU and Envirotech range. As a result, it is able to export significant volumes of this equipment to sister companies worldwide.
“While many competitors rely on distributors and agents to deal with customers, Weir Minerals Africa has over the years established an extensive branch network across the continent,” he says. “This footprint ensures our direct contact with customers, so that they receive the same high level of service irrespective of their location. They also have direct access to our highly skilled and experienced product experts.”
South Africa’s oil, gas and petrochemical market is based on stringent global standards, and Efficient Engineering’s pressurised equipment division has shown it is up to the mark in consistently meeting these demands.
It has been little more than a decade since the division was launched, but the company has already established a customer base that has become accustomed to the highest level of quality and certification. According to Gerhard van Zyl, Business Unit Manager of the pressurised equipment division at Efficient Engineering, the company’s success is based on its imbedded experience, its specialised infrastructure, skilled artisans and its certification and compliance with global standards.
“From preliminary design through to fabrication and delivery, our customers are confident in our ability – having experienced our commitment to service levels for many years now,” says van Zyl. “
He highlights that the oil and gas industry adheres to the strictest technical requirements, so the company has always positioned itself in line with the highest standards and protocols. This is supported by its fully integrated ISO 9001 quality certification and ISO 45001 occupational health and safety management system.
“In fact, customers in our sector will often also conduct detailed audits on our capability before trusting us with any of their contracts,” he says. “Our progress to date is therefore built on earning their trust, through our compliance and, consistent delivery of quality while providing cost effective results.”
Among the demands on the technical side are that fabrication must be guided by a full engineering package including quality plans, welding procedures and detailed equipment performance and testing specifications. Van Zyl says customers are also aware that the company has its own certified professional engineer with international accreditation to ECSA standards who signs off on its designs before these progress to a SANAS-approved inspection authority.
“We have the infrastructure to conduct almost all tasks in-house and can therefore control quality and lead times very closely,” he says. “We also source the materials – which are often specialised to suit specific applications – from trusted local and overseas vendors.”
In the pressurised equipment segment, welding skills and compliance are vital to ensuring quality and safety, he emphasises. Efficient Engineering also has internationally qualified welding engineers, recognised by the Southern African Institute of Welding, who conduct the prerequisite in-process welding inspections during fabrication.
The market’s trust in the pressurised equipment division can be demonstrated through the completion of a number of impressive projects. In one of the leading examples of this, the company locally produced the largest liquid petroleum gas (LPG) storage ‘bullets’ yet to be fabricated in the southern hemisphere. These measured 70 metres long and six metres in diameter, weighing 580 tonnes each. Five were produced for a gas storage facility on South Africa’s west coast.
“The division is also involved in maintenance and replacement of plant and equipment during shutdowns, where our capabilities have created a real niche for us,” says van Zyl. “Customers really appreciate the pride that we have in our work, our attention to detail and our ability to work in line with their extremely demanding shutdown schedules.”
Its well-equipped Germiston premises includes column and boom welders that can operate up to six metres high and with a six metre reach and automatic state-of-the-art orbital tube-to-tube sheet welding equipment, as well as non-destructive hydraulic testing and coating applications in its dedicated, environmentally friendly grit blasting and painting facilities.
The Mangosuthu University of Technology (MUT) in KwaZulu-Natal bestowed an Employer Excellence award on Pilot Crushtec for the practical support it gives to engineering students.
The award was accepted at an MUT awards dinner at Durban’s International Conference Centre last year, according to Tania Tarr, director of human resources and organisational development at Pilot Crushtec. It was in recognition of the many MUT students who had spent time at Pilot Crushtec to fulfil the practical requirements of their National Diploma.
“For over a dozen years, we have brought mechanical and electrical engineering students into our facilities from Universities of Technology around South Africa,” says Tarr. “We have made it a priority in our HR strategy, as these practical phases of the diploma are compulsory – so students cannot graduate without them.”
Pilot Crushtec has given practical experience to almost 70 young graduates in the past thirteen years.Pilot Crushtec was recognised with an Employee Excellence award from the Mangosuthu University of Technology – Tania Tarr, director HR for Pilot Crushtec receives the award from Prof B.F. Bakare, Acting Dean Faculty of Engineering.The Pilot Crushtec skills development programme plays an important role in developing the talent pipeline. Fostering skills development in the engineering and mining sector is a focus for Pilot Crushtec.
The company has had almost 70 students pass through their practical phases at its Jet Park facilities in Gauteng over the past thirteen years. The diplomas require them to complete one practical phase over six months in a workshop environment. This phase involves mainly hands-on work that they do independently. There is also a requirement for a second practical phase that students must undertake in an engineering design environment. This typically needs more personal interaction between Pilot Crushtec people and the students.
She explains that the programme plays an important role in developing Pilot Crushtec’s talent pipeline, and is also a deliberate effort to foster skills development and transformation in the engineering and mining sector as a whole.
“By the time these engineering students are required to undergo the practical phases, they have invested themselves completely in their academic journey,” says Tarr. “It is tragic to see so many of them struggling to find placement at a company to complete these compulsory stages – without which they cannot graduate.”
About 10 of the best graduates were permanently employed by Pilot Crushtec, having proved themselves at a stage when the company was looking to fill specific positions. She mentions that one of the graduates even went on to become best salesman of the year.
“A good indication of the quality of these graduates and our nurturing process is that some find their way into our demanding Support Link customer service area,” she says. “This can only be achieved after developing an in-depth understanding of our products’ mechanics, electronics, performance and maintenance.”
She highlights the importance of working experience to add real value to students’ theoretical training. This includes building the right attitudes and approaches in the workplace, alongside the practical skills. Pilot Crushtec engages its whole team to guide, train and support graduates during their practical phases.
“As and when we have the requirement, we can offer employment to the most outstanding graduates,” she concludes. “This ensures that we sustain our legendary after-sales service while helping create a productive future for the leaders of tomorrow.”
Constantly improving its technology and value offering to the market, SEW-EURODRIVE recently launched its innovative AMS adapter with added features to benefit the end-user.
Andreas Meid, SEW-EURODRIVE head of engineering.
According to Andreas Meid, SEW-EURODRIVE head of engineering, the company’s adapter has always fulfilled a valuable role in the company’s product line-up. Allowing SEW-EURODRIVE’s IEC motor to be integrated with an SEW-EURODRIVE gearbox, the AMS adapter has now been upgraded with even more refinements in mind.
“The first improvement we introduced with this AMS adapter is to make it more compact,” says Meid. “Its smaller footprint allows users to install it more easily in areas where space is constrained; in fact, we have been able to reduce its dimensions by up to a full 25%.”
The bearing selection in the AMS adapter has also been reviewed to optimise the bearing life relative to the operating temperatures. He highlights the growing demand in the market for longer service intervals and more uptime, to which this upgrade is a proactive response.
“We have also considered the specific requirements of vertical installations, and included a drain hole to ensure that any liquid can easily exit the adapter,” he says. “The flinger transports the liquid to the through bores in the intermediate flange, where it can drain out.”
This is important because it means that liquid will not enter the bearings and gears – thereby ensuring that the components can achieve the longest possible operating life. Customers have always appreciated the reliability and low cost of ownership of SEW-EURODRIVE’s offerings, says Marcio Sicchiero, SEW-EURODRIVE head of exports.
SEW-EURODRIVE’s newly launched AMS adapter.The SEW-EURODRIVE AMS Adapter has features to benefit the end-user.
“The AMS adapter comes from the same heritage of high-precision German engineering,” says Sicchiero. “The range of frame sizes also makes it versatile across many industry applications; we offer 12 sizes from IEC 71 to IEC 280.”
There was an enthusiastic response to the new version when it was first launched at the Electra Mining exhibition in South Africa last year. It was also introduced to existing users of the AM adapter, who responded positively to the improvements. The innovation is being manufactured at a number of SEW-EURODRIVE’s plants around the world.
“The AMS adapters, together with our gearboxes and high efficiency IEC motors, offer customers a full package that comes with a two-year extended warranty,” he says. “There is the convenience of sourcing from one supplier, as well as the peace of mind when it comes to support and servicing – we look after all that.”
He notes that this package comes already assembled, reducing the time and cost – not to mention any operational risk – of trying to assemble components on site. Among the most common applications of the AMS adapter, motor and gearbox are in agitation and mixing activities in the mining and water sectors.
A leading South African coal producer will be supplied with Booyco Engineering’s purpose-designed heating, ventilation and air conditioning (HVAC) systems for its 8E locomotives.
The order is for six of these specialised HVAC units, to be manufactured and installed by Booyco Engineering, says the company’s managing director Brenton Spies.
“We first developed an HVAC system for this class of locomotive almost 20 years ago, and we have supplied close to 100 units to South Africa’s main freight rail operator,” says Spies. “They have certainly stood the test of time. With regular maintenance, they have shown how well they perform over many years.”
Designed and manufactured in-house at Booyco Engineering’s Germiston facilities, the 8E HVAC units are equipped to withstand the harsh conditions of rail and mine-site applications – including shock, vibrations and dust. The 8E locomotive was first released in the early 1980s, with a design that did not include air conditioning equipment for the operator’s cab.
The 8E HVAC units are equipped to withstand the harsh conditions of rail and mine-site applications – including shock, vibrations and dust.The updated 8E HVAC system design incorporates various technological improvements. A more energy efficient refrigerant compressor is one of the technological upgrades in the new 8E HVAC system design.
“When HVAC systems became a requirement, locomotive owners soon realised that the rail environment was too harsh for conventional, off-the-shelf commercial systems,” he says. “To achieve the reliable performance and longevity that was expected, a special design was required which was initially installed in 2003.”
For this new order, Booyco Engineering has modernised the initial 8E HVAC system design to incorporate various technological improvements. These include a more energy efficient refrigerant compressor, updated electrical switchgear to railway rated versions and upgraded heating capacity, he notes. Judging from the company’s extensive experience in the rail industry, however, there are still companies operating in this sector that are not fully aware of the physical demands and harsh environment that rail transport places on HVAC systems.
“Air conditioning systems that are designed for use in buildings, for instance, are still sometimes installed in locomotives – but they seldom last more than a few months, if not weeks,” he explains. “Some of these do not even last a single trip on a long distance train journey, such is the intensity of the vibration and shocks.”
Booyco Engineering has built its reputation on decades of experience – designing and manufacturing bespoke engineered solutions for a range of specific applications in different sectors, explains Grant Miller, executive director at Booyco Engineering.
“In the South African rail sector, there are also space constraints to consider when designing for locomotives, due to our narrow-gauge rail specifications,” says Miller. “Our internal design capacity allows us to develop and test solutions that are fit for purpose.”
This includes designing for uncommon voltages which are not ideal for many electrical components, he notes, as well as coping with significant voltage fluctuations. Regulations governing health and safety, – both in the mining and rail sectors – now also make it vital that HVAC systems are both effective and reliable. These requirements are in place to avoid any safety incident from occurring as a result of an unconducive working environment, he explains.
This includes designing for uncommon voltages which are not ideal for transformers, he notes, as well as coping with significant voltage fluctuations. Regulations governing health and safety, , – both in the mining and rail sectors – now also make it vital that HVAC systems are both effective and reliable. These requirements are in place to avoid any safety incident from occurring as a result of an unconducive working environment, he explains.
“HVAC’s are classified as a type A Hazard and should there be a lack of cooling in an operator’s cab, this could lead to an operator being entitled to stop work,” he says. “The cost of an ineffective or faulty HVAC system would then be measured not simply in repair or replacement costs, but in terms of vastly more costly downtime and general operational disruption.”
Key to Booyco Engineering’s ability to delivery world-class quality solutions is its conformity to ISO 9001:2015 – and its approval by several OEM railway equipment companies. Each design undergoes stringent type testing to Booyco Engineering’s internal standards and to customer specifications. Systematic quality checks are also conducted through a detailed build process, followed by comprehensive production testing.
Proximity Detection Systems (PDS) started out as a valuable mechanism to warn operators and pedestrians of imminent danger, but today they play even more powerful health and safety roles.
These include gathering and analysing site-specific data that allows management to plan safe and efficient traffic flows. According to Anton Lourens, CEO of leading PDS developer Booyco Electronics, the rapid development of digital communication and sensor technology is opening many doors to higher safety levels.
“PDS can today locate vehicles and personnel in real time, giving mines the ability to recognise patterns in traffic movement,” says Lourens. “From this starting point, traffic management strategies can be developed to keep people away from trackless mining machinery (TMM).”
Importantly, the data collected can identify ‘hot spots’ where potential collisions could occur. This makes a systemic contribution to the mine’s safety, as management can adapt traffic management plans to create segregation of people from equipment, and equipment from each other. This feeds constructively into the mine’s ongoing risk assessment responsibilities, and provides strong mitigation methods.
The Booyco CXS solution providing a comprehensive and integrated response to Level 7, Level 8 and Level 9 safety levels – as defined by the Earth Moving Equipment Safety Round Table (EMESRT).
“This is giving PDS a vital role in each mine’s code of practice (COP), making these interventions specific rather than generalised,” he says. “Every mine has its own specific traffic conditions and operational requirements, for instance, and PDS helps provide insight into those conditions so that the COP is kept relevant and effective.”
He points to the Booyco Electronics Asset Management System (BEAMS) software suite as an example. This is essentially a central information hub that gives mines the insight they need into operational interactions.
“BEAMS analyses a huge amount of data from vehicles, uncovering important aspects such as unsafe patterns of behaviour,” says Lourens. “This gives management the basis for responding with strategies that mitigate risk and enhance safety.”
He also highlights the growing use of sensor technology in enhancing the health and safety benefits of PDS. These innovations have, as example, added a close-up and more accurate sensing approach to the traditional long-distance detection technology.
“We have designed our CXS range of PDS solutions so that we can readily augment the system architecture with sensors,” he says. “By combining various sensing technologies, we develop flexible solutions that make for safer working environments – as they are specific to customer and operational requirements.”
Traffic management strategies can be developed to keep people away from trackless mining machinery.All Booyco PDS systems are tested rigorously to ensure they meet the required standards.
Lourens reiterates that the application of PDS technology can only be effective when based on a thorough risk assessment. This, he says, will ensure that the mine’s selection of a solution is relevant to their needs and conditions.
“This means a well-planned process that includes careful change management and real engagement with all involved,” he explains. “By taking the required steps, PDS can play a significant role in enhancing health and safety – while providing long-term benefits in productivity.”
Recycling of waste material is a no-brainer for the planet, and suitable screening applications have to be developed to make it a reality.
“Everyone wants to recycle more; it makes sense environmentally and it’s the right thing to do,” says Kwatani business development manager Warren Mann. “Recyclable waste is generally low value, however, so any recycling solution must have a highly cost effective strategy for separating different elements of the product.”
The Kwatani engineering department where all R&D and design work resides.The test screen in the laboratory at Kwatani used for various component screening.Kwatani round separators typically used for low volume screening.
Mann highlights that, unlike most mined material, the shape and other characteristics of products that industry wants to recycle are often irregular and difficult to screen. Strands of copper wire, for instance, simply do not pass through a screening medium as easily as aggregate stone or sand. Similarly, chips of rubber produced by a tyre shredder are also likely to be highly varied in shape, size and consistency.
“This means that anyone wanting to screen industrial waste in a commercially sustainable way is unlikely to find an off-the-shelf screen design to do this,” he explains. “Detailed testing of material on different screens – or with a range of screening dynamics and parameters – is usually the only way to find a cost effective solution.”
The real challenge is that most recycling demands an economy of scale, in which a sufficient volume of material can be effectively recycled to overcome the low margins of the final product. It is therefore not enough to find an in-principle solution; the duty that a screen must accomplish is a key variable in its success.
“Kwatani has decades of experience in understanding customers’ screening needs, so we can design and manufacture a screen that is fit-for-purpose,” he says. “This expertise extends across a range of material and commodities – making us familiar with how different products respond to screening.”
The company’s testing laboratory is where investigations tend to start, and customers can witness how their material performs under different screening conditions. Mann explains that a machine used to screen corrosive products like crushed batteries would need to be built from specialised materials of construction , for example. There are also materials that tend to clog the screening surface, so a self-cleaning kit may be required.
“No matter what the material is to be recycled, Kwatani is well placed to test how it responds to a range of screening options, and to make recommendations to customers,” he concludes. “The testing we conduct will give recyclers valuable insights into how best to proceed, by avoiding the trial-and-error method that costs them more in terms of time, effort and resources.”
