CONCOR HEAD RALLIES SA TO FIGHT VIRUS

“South Africa has boldly taken the right steps to avoid the high number of coronavirus-related deaths experienced by many countries; we just need to stay strong, stay healthy and stay at home.”

This is the message from Concor CEO Lucas Tseki as the country enters an extended lockdown for another two weeks.

“This is an historic challenge facing the planet, and we are all called upon to make our own contribution in these difficult and uncertain times,” Tseki says. “The current crisis highlights more than ever how interconnected we all are – across communities, countries and continents. We are all in this together, and must act responsibly toward a common goal of stemming the spread of the virus.”

He commended President Cyril Ramaphosa “for his grit and courageous leadership in the face of adversity”, noting that the decision to extend the national lockdown could not have been easy. The lockdown’s impact on business was clearly front-of-mind for decision-makers, but the global spread of the deadly virus demanded that tough choices be made.

“For Concor’s executive team, our primary focus at the moment is the group’s sustainability, so we continue to engage our business partners and explore opportunities within the market,” he says. “We are doing everything possible to mitigate the financial impact of the coronavirus including preparation for responsible resumption of operations post the lockdown– and we are confident that together we will weather this unprecedented storm.”

Concor is one of the largest players in the sub-Saharan African infrastructure and construction sector, and is a proudly Level 1 B-BBEE company.

ZEST WEG ADDS GEARED MOTORS TO PRODUCT LINE-UP

A range of WEG geared motors – with benefits including efficiency and reliability – will soon be available to customers in South Africa and the rest of the continent from Zest WEG.

According to Zest WEG national sales executive Johan van Niekerk, the WEG WG20 range is a natural extension of the company’s offering in electric motors, and will be available from the third quarter of 2020. The geared motors will be distributed and supported through Zest WEG’s established footprint of strategically located branches and outlets across the continent.

“In keeping with our local production philosophy – and to reduce lead times to customers – the geared units will be assembled in South Africa,” van Niekerk says. “Zest WEG has made a substantial investment in new assembly facilities, including hydraulic presses and assembly tooling.”

He also notes that the geared motors will allow the company to expand services in new markets including the packaging, recycling, food and beverage sectors.

Cas de Jager, Zest WEG geared motor specialist, highlights that local assembly allows reduced time-to-market.

“Underpinning our quick turnaround time will be our skilled employees and local stockholding of a full range of gears, flanges, housings, shafts, bearings, oil seals and other components,” says de Jager.

The components for the geared motors are manufactured by Watt Drive in Austria, an established gear technology specialist and part of the global WEG group. Watt Drive offers a complete range of combinable drive systems for production machines and industrial manufacturing plants. In addition to providing high quality components, the company is also training Zest WEG personnel at its Austrian facility and will regularly send technical experts to continue building capacity in the South African operation.

There are various benefits inherent to geared motors, says de Jager.

“A key improvement delivered by geared motors is their high level of efficiency,” he says. “Only about 1,5% of mechanical efficiency is lost per gear stage, so a two-stage gear unit would be about 97% efficient.” He highlights that they are also very reliable, robust and durability, making them economical to maintain.

Van Niekerk says Zest WEG’s extensive footprint around South Africa and linkages with the rest of the continent positions the company well to introduce the WEG WG20 range to new and existing markets.

“Our geared motors will be given the high levels of service and after-market support for which we are well-known,” he says.

SAFE, LIGHTWEIGHT WALKWAYS FOR MINE RESCUE DRILL

Mentis Africa supplied positive-grip, pressed-section planks and walkways from its well-known Die-Line range for the Chamber of Mines rescue drilling unit based at Colliery Training College (CTC) at eMalahleni in Mpumalanga.

The walkway’s non-slip features, combined with its high strength to weight ratio, made it ideal for the vehicle-mounted drilling unit, according to Rene Lombard, external sales representative at Mentis Africa. The walkways and planks have been installed all around the drill vehicle to facilitate easy movement of personnel. 

“Its positive serration ensures good traction even in muddy and wet conditions, enhancing the safety and efficiency of people working on the drill during a mine rescue mission,” says Lombard. “Significantly, Mentis Die-Line walkways are lightweight so while being very strong, adds little extra weight to the vehicle.”

The rescue drill is on 24-hour standby to be deployed, with the assistance of CTC staff, in the case of mine accidents. It can drill a 150 mm diameter hole into the underground area where an accident has occurred. This allows the area to be assessed by camera, and for food and water to be supplied. It is also capable of drilling a large-diameter hole of 635 mm in diameter, down which a capsule is lowered to bring trapped mineworkers to surface.

“The Mentis Die-Line products are simple to install, requiring no specialised tools and minimal welding or clipping to supports,” Lombard says. “All the necessary bolts, nuts, washers, fishplates, jointing channels, saddle clamps, splice plates and mesh clips are provided.”

Lombard notes that the Mentis Die-Line walkway sections – plants with 2 mm thickness and walkways sections with a 2,5 mm thickness, can be provided in either 500 mm or 750 mm widths at a standard length of 2.4 m.

“Where the walkway or panel is subject to a corrosive environment – like harsh chemicals or saltwater – the mild steel construction can be bitumen-dipped or galvanised,” she says. “This allows these versatile products to be used in a wide variety of applications.”

AFRISAM READYMIX FACILITATES DURABLE CONSTRUCTION OF BRAKPAN RESERVOIR

AfriSam’s responsiveness and ability to deliver according to specification made this leading construction material supplier the preferred readymix concrete partner for the new Brakpan reservoir being constructed by Superway Construction.

According to Xolani Mbatha, technical product team leader at AfriSam, the company’s quality readymix creates concrete possibilities for the production of durable infrastructure.

“Productive collaboration between AfriSam and contractors is critical for the successful execution of any project, and this is especially so when it comes to defining and meeting product specifications and facilitating delivery within construction programme scheduling,” he says.

An excellent example of the success of such a cooperative partnership is clearly visible at the site of the reservoir currently under construction at Sallies Village in Brakpan.

The City of Ekurhuleni, as part of a commitment to address water capacity constraints within its region, has embarked on building 29 reservoirs during the period 2018 to 2021. This will see a combined storage capacity of 550 megalitres being added to the infrastructure.

Superway Construction won the contract for the construction of a new reservoir adjacent to the existing Brakpan reservoir amid fierce tender competition. Contract manager, Eugene Gibbard, acknowledges that being awarded this contract is gratifying for Superway Construction and recognises the contractor’s experience in a wide variety of construction and infrastructure projects.

The scope of this project includes the construction of the reservoir and all ancillary works including the perimeter fence, new access road, chambers and guardhouse. Elements where concrete is specifically required include the strip footings, walls, column bases, columns, column heads and roof.

The implementing agent, the Development Bank of Southern Africa, issued detailed project specifications and when completed, the 18-megalitre reservoir will be 8.2-metre-high with a diameter of 60 metres and will have a slightly sloped concrete roof.

AfriSam secured the contract to supply 2 500 m3 of readymix concrete based on its ability to meet the stringent quality specifications. All concrete supplied will be as per the consulting engineers’ material specification for an impermeable water retaining structure.

“Previous experience with AfriSam’s professional technical team and their responsiveness and ability to deliver according to client specification made them the preferred readymix concrete partner for this reservoir project,” Jurie Moolman, Superway Construction site manager, says.

SANS 2001-CC1-2012, the specification for structural concrete that is being used for this project, calls for fly ash as a supplementary cementitious material (SCM). As the standard operational mix supplied by AfriSam’s Sub-Nigel plant contains slagment, the operations team had to be pro-active in introducing a customised concrete mix changing from using slagment to fly ash in order to meet the project requirement.

The slump was initially specified at very low levels between 10 mm and 60 mm. This was of concern considering the high minimum binder content specified, ambient temperatures and the need to pump the concrete. Close consultation between AfriSam’s technical team, Superway Construction and the consulting engineers resulted in an agreed slump on 125 mm in conformance with SANS 878.

The careful calculation of the water:cement ratio to not exceed 0,5 ensured that the tight shrinkage specification of between 0.3 and 0.45 mm will be met. A crystalline waterproofer is incorporated into the mix to further enhance permeability properties while a CHRYSO curing compound will allow adequate cementing reactions to aid strength gain, impermeability, abrasion resistance and durability. A well-graded aggregate is used for this special application.

This custom mix underpins AfriSam’s capability in designing and supplying a fit-for-purpose readymix concrete; in this case a workable mix which accommodates placing techniques and meets the project specification.

The reservoir will be constructed in three lifts for the full circumference, ensuring stability for the reservoir walls. This necessitated a continuous supply of readymix concrete and AfriSam allocated seven readymix trucks to each pour, and when required this was increased to 12 trucks.

Initial planning has already commenced for the roof to be poured in one pour. Moolman says that while this will be a daunting single pour of 630 m3, the volume of the pour will not be the biggest challenge; this will be to ensure an acceptable finish over such a large area. Detailed planning will be done to ensure all the required resources are available to achieve this milestone.

Queen Mabunda, territory sales manager at AfriSam, says that AfriSam has been able to contribute positively to maintaining the integrity of the project. “Our extensive experience and knowledge within the readymix sector and access to resources within the company, including the Centre of Product Excellence, allowed us to provide Superway Construction with the readymix solution it needed on this project. Further, our stringent quality control measures at AfriSam’s Sub-Nigel plant provided the assurance that the customer needed when it came to consistent product quality.”

AfriSam has supplied readymix concrete and technical advice successfully to a number of reservoirs constructed in the Ekurhuleni region. Mabunda says that the timely response of using fly ash to meet the project requirement will position AfriSam well in the market to supply other similar projects.

Work on site commenced in May 2019 with a contract completion date set for June 2020. Prior to the lockdown, Superway Construction was on track to hand over the project by the end of May, ahead of time and on budget.

FLSMIDTH’S LABORATORY CONTRACT AT SALDANHA RENEWED

Automated laboratory leader FLSmidth has had its Operate and Maintain (O&M) contract at the Saldanha Iron Ore Terminal on South Africa’s west coast renewed for another three years.

The company has successfully operated the quality control laboratory at Saldanha – Africa’s largest iron ore export facility – for the past eight years, according to Martin Matthysen, Director, SPA (sampling, preparation and analysis), Sub Saharan African and Middle East at FLSmidth.

“An average of approximately 8500 tonnes of iron ore per hour pass by conveyor from the rail head to the ship during loading,” says Matthysen. “Our automated laboratory located above the conveyor must sample and test from this ore stream, delivering accurate and precise data timeously to stakeholders.”

He says the automated system installed by FLSmidth for a leading iron ore producer takes a representative sample of the ore and processes it though the laboratory with minimal human intervention. It is the only laboratory with ISO 17025 accreditation for the iron ore sector, complying with standards ISO 9516 for chemical analysis, ISO 4701 for particle size determination, ISO 3087 for moisture analysis, ISO 11536 for loss of ignition analysis and ISO3082 for sampling.

“Operational quality and stringent standards are vital in this process, as both the seller and the buyer of the ore must be confident that test results on the shipment are accurate and precise,” he says. “The laboratory analyses the material’s chemical composition, particle size, moisture content and loss of ignition levels – as these indicators all impact on the final price of the product.”

The accuracy of results is further checked by participating in a proficiency testing scheme as well as ‘round robin’ analysis – in which samples are verified by laboratories selected by end-customers elsewhere in the country and world.

“We are pleased to have delivered exemplary past performance at Saldanha, in service of our client’s best interests and efficient operation,” he says. “Our ongoing focus on quality has also ensured that we remain compliant with all-important ISO standards in our daily processes.”

He adds that the automated laboratory’s ability to deliver reliable and accurate results as quickly as it does, is also a vital benefit to the client.

OUTPUT AT OMV STILFONTEIN BOOSTED BY UPGRADES

A range of upgrades at OMV’s aggregate and sand plant at Stilfontein in North West province has led to a 40% capacity growth over just 18 months.

OMV’s plant processes quartzite rock dumps generated from shaft-sinking in the area to produce road construction material. While production capacity could previously be pushed to about 1,000 tonnes a day, the plant’s daily output now regularly reaches some 1,400 tonnes.

One of the first improvements was the installation of a 100 metre overland conveyor extension from the dump to the feed box. This improved productivity and overcame the loading constraints experienced previously with the use of front-end loaders. A new feed box was also installed – with its own six metre conveyor belt – to feed the overland conveyor. This addition reduced excessive wear and tear, improving uptime on that part of the plant.

Production has also been improved with the incorporation of a vibrating pan feeder on the secondary crushing plant, regulating the flow of material onto the conveyor belt. Supplied by Weir Minerals Africa and installed by the OMV team, the feeder was the first step in the automation of the secondary crushing process.

A programmable logic controller (PLC) and human machine interface (HMI) has been added to the circuit to automatically regulate the feed box. This allows the choke-feeding of the crusher, which is difficult to accomplish manually.

To raise sand production, a deep cone thickener was installed to extend fines separation. Among the benefits of the new fines separator is that it reduces the amount of saleable material discharged to tailings. It recovered about 10% of saleable product previously discarded into the tailings pond, and contributed to the plant’s sand production capacity rising from 25 to 33 tonnes per hour. This step also reduced the plant’s environmental impact by reducing the quantity of tailings.

KWATANI’S SCREEN SOLUTIONS CUSTOM-BUILT FOR TONNAGE AND LOWEST TCO

When a South African diamond operation needed to improve the performance of its degrit screens, Kwatani customised a bespoke solution that doubled the feed-rate.

The customer was operating a number of multi-slope screens to dewater product between 0,8 mm and 5 mm in size, before it was treated by dense medium separation (DMS). However, the screens were causing a severe carry-over of water onto the conveyor belt to the DMS.

“The feed-rate on each screen was being limited to about 250 tonnes per hour,” says Kwatani CEO Kim Schoepflin. “We tackled this by designing and manufacturing a customised multi-slope screening machine to fit the customer’s existing footprint.”

Schoepflin says Kwatani’s replacement was able to double the feed-rate to about 500 tonnes per hour, and with minimal water carry-over. As a result of the success of this unit, the customer requested Kwatani to replace the whole bank of screens.

In another contract, a customer asked for assistance with underperforming screens that could not deliver the original design parameters. They also wanted to improve the tonnage throughput by 17%.

“We conducted a careful evaluation in collaboration with the customer, and came up with an innovative and economical solution,” Schoepflin says. “Simply replacing the existing screens with Kwatani’s new larger screens would have been costly and time-consuming, so we decided instead to replace the screen’s existing gearboxes.”

The replacement gearboxes delivered greater vibration, but without exceeding the output torque that the existing motors driving the gearboxes could provide.

“Drawing from our portfolio of locally designed and manufactured exciter gearboxes, we were able to implement this solution very quickly,” she says. “The two new exciter gearboxes were delivered to site and were in operation within two weeks – successfully and immediately increasing the screen’s throughput.”

The benefits to the customer did not stop there, says Schoepflin. The newly optimised operating parameters meant that the material bed depth was lower, so the drive motors drew a lower amperage and reduced the cost of power consumed.

“Our customised screening and feeding solutions – developed by our in-house team of experienced mechanical engineers and metallurgists – are based on consultation with each customer,” she says. “The result is a design that delivers the optimal processing performance and tonnage at the lowest cost of ownership.”

SLURRYSUCKER WINS THROUGH IN SALTWATER APPLICATION

A recent two-week trial on a mine on South Africa’s west coast has again proved the value of Integrated Pump Rental’s SlurrySucker dredging unit – even in saltwater and high-volume conditions.

The mine was facing a real challenge with its main process water pond; it would fill with sediment within a week, and the sea water which filled it is highly corrosive. The mine was also looking for a safer and more cost effective option than the divers, equipped with manually operated suction pipes, it was employing.  

“This large pond – about 70 metres square and eight metres deep – is central to the mine operation as it feeds all the process plants,” says Ruaan Venter, rental development manager at Integrated Pump Rental. “It is therefore vital that sediment is removed continuously, quickly and in large quantities.”

During the trial, the SlurrySucker was able to pump 250 cubic metres per hour of sediment with a solids content of 30 to 40%. This allowed the specialised dredging equipment to remove 60 to 70 tonnes of sediment from the pond every hour.

“When in contact with conventional metal pump components saltwater is extremely corrosive, and over time can cause a lot of damage to the equipment leading to the frequent replacement of wear plates and impellers. In addition, the integrity of the framework will also be compromised,” says Venter. “Under these conditions and to mitigate against corrosion, we provide our customers with a full stainless steel pump solution with rubber-lined pipes to transport material from the pond.”

The success of the trial has raised the interest of other mining operations along this coastline, where sea water is also used in the process plants.

“Demanding conditions like these would warrant the customer considering a purchase option,” he says. “It is likely that the SlurrySucker would be operational every day on these ponds, making this specialised equipment a valuable investment in the efficient running of the plant.”

BCCEI WAIVES LEVIES FOR APRIL AND MAY 2020 BRING RELIEF TO SECTOR

The Bargaining Council for the Civil Engineering Industry (BCCEI) took an unprecedented step in April 2020 when the Council announced that it would waive the BCCEI administration and dispute levy contributions for that month. In another move aimed at bringing much needed relief to an already ailing industry sector, the BCCEI has announced that this waiver will be extended to the month of May 2020.

This is a significant gesture as the BCCEI does not receive any grants or subsidies from the government and its only source of income is through the administration and dispute levies which is received from registered companies in the civil engineering industry. These levies are used for the running and day-to-day operations of this bargaining council.

BCCEI general secretary, Nick Faasen says that the Council decided on the step as it is fully aware of the situation in which both employers and employees find themselves at this time.

“Budgets and cash flow are under immense pressure following the declaration of the National State of Disaster and the subsequent implementation of the nationwide lockdown which was further extended. We acknowledge that many people in our sector will, in all probability, have a reduced income and we believe it is essential that we work together to find ways to reduce expenses, wherever possible,” Faasen says.

The BCCEI, representing two unions and two employer organisations, provides a range of valuable services to the civil engineering sector. Currently, the Council continues to operate through non-contact methods and remains committed to prompt service delivery to the industry.

WEBA CHUTES TAKE AFRICA IN THEIR STRIDE

With its custom-designed transfer point solutions at mines across Africa, Weba Chute Systems has proved its chutes in commodities from platinum to diamonds to gold, coal and copper.

In addition to mining hotspots including Ghana, Mali, the Democratic Republic of Congo (DRC), Zambia, Zimbabwe and Botswana, Weba Chute Systems have been installed in countries like Tanzania, Mauritania and Eritrea. Authorised Weba Chute Systems agents are deployed to support customers in key countries, while technical experts from the company’s head office in Germiston, Gauteng, are on call to assist.

“Mines across the continent have recognised the value of our custom-designed chutes,” says Wade Vandenberg, Weba Chute Systems’ technical advisor Africa. “Not only do these operations gain the benefits of controlled material flow in their operations, but they experience first-hand how our engineering design extends wear life and reduces maintenance downtime.”

He highlights that better dust control – a key part of health and safety policies in the mining sector – is another important benefit that Weba chutes bring to an operation.

“Our state-of-the-art digital engineering design facilities and expertise makes use of the latest technologies to simulate the specific material flow conditions in each customer’s application,” says Vandenberg. “This allows us to apply our philosophy that no two chute designs are identical, and to scientifically accommodate exact flow characteristics into our design.”

Discrete element modelling allows close control over the flow of material through the chute. This minimises turbulence reducing the levels of dust created in the working area. It also cuts spillage levels, which in turn means a saving of valuable material and less time spent on cleaning activities.

“We work towards the ISO dust management standards, supporting our customers in managing health and safety in this critical area of transfer points,” says Izak Potgieter, systems manager at Weba Chute Systems. “Our testing measures dust down to 0,03 micron particles, to make sure that our designs meet stringent health-related targets.”

Flow control also creates more material-on-material movement to reduce wear on chute liners, ensuring longer liner life when compared to that of conventional chutes. Custom design and use of simulation technology allow for the wear life to be carefully predicted, based on operating conditions.

“Our technical expertise and solutions-oriented approach mean that customers can always rely on us,” says Vandenberg. “When we commission one of our chutes, it is part of an ongoing productivity journey with our customer, no matter where they are located.”