Monthly Archives: December 2020

Client Focus

EAST-WEST LINKS SUPPORT FLSMIDTH’S THICKENER PROJECTS

The use of FLSmidth thickeners in African mining operations has continued to grow, supported by global collaboration across the FLSmidth organisation’s offices in South Africa, China and the USA.

According to Alistair McKay, FLSmidth’s Vice President for Mining in Sub-Saharan Africa and the Middle East, the company is delivering six substantial thickener contracts to mines in Mozambique and the Democratic Republic of Congo (DRC) in 2020. McKay highlights that Chinese companies have been driving much of the growth in the continent’s mining sector.

“In our work in Africa with Chinese customers, we have found that our Beijing office plays a valuable role in ensuring streamlined communication and efficiency,” he says. “This allows a constructive combination of our local knowledge with the ability of our Chinese colleagues to facilitate relationships with our customers in China.”

This differentiator has enhanced FLSmidth’s acknowledged leadership in thickener technology in the region. The company will deliver 25 new thickeners, including high rate, high density and counter-current decantation (CCD) thickeners, in southern and central Africa during 2020.

“The design work for these contracts was conducted by FLSmidth’s centre of excellence in the USA,” he says. “Given our established local infrastructure and experience in this product range, the thickeners were cost-effectively manufactured in South Africa and China.”

While the fabrication and platework was completed using local skills, the FLSmidth on-site technical support presence to construct and commission the thickeners at Chinese-owned mines in the DRC will integrate staff from the Beijing office.

“This improved communication between FLSmidth and the customer has negated the risk of any misalignment that could slow the process down,” he says. “In fact, our Beijing office has become increasingly involved in the full delivery process, fulfilling the role of the project manager. This is significant as the building of relationships across East-West contracts becomes increasingly important.”

FLSmidth offers full-service capabilities in thickener technology, he says, starting with bench or pilot scale testwork to characterise customers’ material. This informs the customer’s flowsheet and equipment selection and sizing, and the right technology application for cost-effective, optimised operation.

Client Focus

RUSTENBURG MALL – BUILT ON CONCRETE RELATIONSHIPS

The new 40 000m² Rustenburg Mall shopping centre remains on track for completion in April 2021, with main contractor Beckers Bouaannemers relying on readymix partner AfriSam for its concrete production capacity and technical know-how.

The project – where construction began in October 2019 – is set to meet its timelines despite three months of lockdown during which no construction activities could take place. According to Barend Becker, director of Beckers Bouaannemers, a large contract like this demands a well-resourced and responsive concrete partner, which is why the company has a long history with AfriSam.

Starting out as a small hardware retailer in Centurion over 30 years ago, with a doorframe installation as its first construction job, Beckers Bouaannemers has grown into a substantial construction company delivering multi-million projects for its clients.

“Over the years, we have built a good relationship with AfriSam,” says Becker. “We know that we can trust them to provide us with excellent service and a quality product. They work closely with us during the construction phase to make sure that our requirements are met.”

Once completed, a total of 14 000m³ of readymix concrete will have been used for the various construction components such as surface beds, columns and other structural elements as well as ancillary work. For this project, the construction team chose a more environmentally-friendly concrete mix that used a slag stone as an aggregate option. This was selected in conjunction with AfriSam, who worked with the project engineer to find an optimal mix design to meet all quality specifications.

“We rely on AfriSam’s expertise in the design of concrete mixes, to provide us with the best-suited product for each specific application,” says Cobus Mouton, contract manager at Beckers Bouaannemers. “All AfriSam products deliver a quality build, but we especially like their surface bed product which has a promising seven-day early strength result and provides a smooth finish.”

Mouton admits it has been a challenging year, with Covid-19 proving extremely disruptive to the company’s construction projects.

“However, our suppliers and subcontractors – including AfriSam – have pulled out all the stops to ensure that we bring this project back on track,” he says. “We are extremely grateful to all our subcontractors for the important role they have played in making up the lost time.”

Despite the disruption of the pandemic, 2020 has been a record year for AfriSam’s readymix plant in Rustenburg. In addition to the Rustenburg Mall, the plant is also supplying readymix concrete for the construction of another large mall in the vicinity. 

“To meet our customers’ demand, the plant operates six days a week during the peak construction period from September to December,” says Gerhardus Maree, operational manager at AfriSam Readymix. “This means starting our supply to customers early in the morning and working through until late at night.”

The increased production for concurrently supplying both these large projects has demanded careful logistical planning from AfriSam. To meet the construction programme requirements, seven more readymix trucks were relocated to Rustenburg from other AfriSam plants in Gauteng.

The large pours on both projects – sometimes between 500 m³ and 600 m³ a day – have meant that raw material management was also critical. With limited silo capacity at the plant, the delivery of cement, aggregate and slag had to be carefully planned with raw material suppliers.

An extra batching plant was also erected on the existing premises to ensure there were no delays in supplying both projects. This plant produces an average of 58 m³ of concrete per hour.

AfriSam’s readymix plant in Rustenburg, in operation since the 1980s, has supplied concrete to Rustenburg landmarks such as the Netcare Ferncrest Hospital, Waterfall Mall, the Royal Bafokeng housing project and Tharisa Mine.

“Our ultimate goal is to provide our customers with the best possible service,” concludes Maree.

Client Focus

ABSOLUTE MATERIAL CONTROL KEY IN MILL FEED AND SCRUBBER TRANSFER POINTS

Mill feed transfer points and scrubber feed chutes are traditionally considered high wear and high maintenance installations. However, according to Alwin Nienaber, technical director at Weba Chute Systems, says by engineering the transfer point to ensure the correct control of material feed into the mill or scrubber it is possible to significantly reduce wear and tear, and consequently maintenance.

Nienaber  explains that the transfer point into the mill or scrubber is critical with problems often arising due to the nature of this application. “This area of the plant is subjected to high velocity, which can cause excessive wear and tear and is linked directly to the speed of material being transferred through the chute.”

Large quantities of water required for the milling process are fed with the material into a mill or scrubber chute. In ball mill applications, steel balls are also fed through the chute into the mill itself. Traditionally, mills are lined with either cast high chrome, manganese or rubber liners, and even though mill feed chutes may have similar lining materials applied, these are not always sufficiently robust to counter the excessive wear caused by uncontrolled discharge of materials.

“Another challenge in this application is the interface between the stationary chute and the rotating mill,” Nienaber says. “Uncontrolled discharge of bulk materials and water will escalate the cost of maintenance, and could result in other related problems, all of which could add up to unnecessary expenditure and added aggravations for the engineers concerned.”

Weba Chute Systems & Solutions has decades of experience in assessing individual applications and providing a solution that will meet the operating parameters and contribute to achieving the lowest cost per ton for the mine.

“By leveraging the Weba Cascade Chute design we can ensure the most appropriate configuration in the head section of the chute and achieve full control of the material with a significant reduction in wear,” he says

With this well-engineered design Weba Chute Systems customers will be able to limit the impact into the lined feed spout section where the water is introduced through a separate flood box. Here, again by controlling the product flow in the Weba chute, customers will significantly reduce the high wear rates that are traditionally experienced in a mill feed spout. This will result in a reduction in the associated costs related to transfer points.

Significantly, Weba Chute Systems & Solutions has more than 5000 custom engineered chutes and transfer points operating successfully across of a range of minerals and applications globally. The company has local representation in all major mining regions internationally.

Client Focus

TRAFO GAINS GROUND WITH DRY-TYPE TRANSFORMER SOLUTIONS

Dry-type transformer specialist Trafo Power Solutions is growing its footprint in mining and beyond with increased take-up of its safe and reliable technology.

“Our contract pipeline is a clear demonstration of the market’s confidence in dry-type transformers, especially for indoor applications, hazardous areas, remote locations and demanding outdoor environments,” says David Claassen, managing director of Trafo Power Solutions.

Recent orders have included a specialised 3900 kVA unit for a large coal mine in Limpopo province. With a primary voltage of 11 kV, this dry-type transformer delivers through four different secondaries of 1810 V, 1500 V, 1400 V and 1200 V. To operate reliably in the dusty outdoor location, it is installed in an IP54-rated enclosure and cooled using air to air heat exchangers

Even during the Covid-19 lockdown, supply from the company has continued. Two 2000 kVA dry-type transformers were installed in a modular substation for a diamond mine expansion in Sierra Leone.

Trafo Power Solutions also recently supplied Africa’s largest liquified natural gas (LNG) project, under construction in northern Mozambique. Eighteen dry-type transformers are already on site, inside modular substations for the project’s first construction camp of about 9,500 contractors. Also being supplied are 20 specialised dry-type transformers for the project’s gas plant.

“We have been active in many other industries too, such as telecommunications, health, food and beverages, and commercial buildings,” says Claassen. “Our strategic partnership with a leading global player, TMC Transformers in Italy, allows us to leverage world-class technology and expertise for application in Africa.”

He highlights Trafo Power Solutions’ responsiveness to specific customer requirements, and its experience in custom engineering solutions that are fit for purpose. Backing up these offerings is a flexible, 24/7 support service from technicians in South Africa, who are ready to provide interventions on site where necessary. The company also provides customers further access to the engineering expertise at TMC Transformers’ state-of-the-art design and manufacturing facilities.

Client Focus

BOOYCO EXPANDS PDS FOOTPRINT TO NAMIBIAN MINE

Proximity detection leader Booyco Electronics is equipping 19 mechanised mining machines with its latest Booyco CXS proximity detection solution to enhance safety during the development phase of underground operations at Namibia’s largest gold mine.

According to Anton Lourens, Booyco Electronics CEO, the order was placed by long-time customer Murray & Roberts Cementation, who will be establishing the underground stoping horizon for the Wolfshag zone of B2Gold’s Otjikoto mine.

The contract also includes sensing devices for 120 underground personnel on the operation, which will be located in the employee’s cap lamp to provide an alarm.

“Our equipment will help achieve the highest level of safety by mitigating the risk of collisions between pedestrians and vehicles, and between vehicles, on this project,” says Lourens. “The installation of our CXS units is in line with the commitment by the mine and the contractor to zero harm in the workplace.”

The Cementation Lewcor JV contract will take 28 months. Lewcor Mining is a Namibian company with extensive mining experience in that country. The contract includes a decline of 5.0 m wide by 5.5 m high being driven to the orebody from a portal in one of Otjikoto’s depleted open pits. The operation will be highly mechanised, with equipment including drill rigs, dump trucks, load-haul dumpers and utility vehicles, as well as shotcreting and ancillary equipment.

Lourens highlights that Booyco Electronics’ latest generation CXS system being used on the project is a comprehensive and integrated proximity detection solution. The technology takes a step beyond being just a warning system to becoming a true collision avoidance system.

“The CXS system on this project will deliver Level 7 and Level 8 capability in terms of the Earth Moving Equipment Safety Roundtable (EMESRT), and can also accommodate Level 9,” he says. “Although there is not yet a legal requirement for collision avoidance systems in Namibia, our customer and the mine adopt a global best practice approach to all aspects of safety in mining operations.”

With the mine’s location more than 300 km north of Windhoek, it was important that the equipment is robust and reliable to ensure maximum uptime, he says.

“To ensure that the equipment performs optimally, we have trained the customers’ artisans on how to look after it,” Lourens says. “A qualified serviceman from Booyco Electronics will also visit the site regularly to audit performance, assess the equipment and conduct any necessary maintenance.”

A pioneer of proximity detection systems in South Africa, Booyco Electronics’ home-grown technology has seen wide take-up in underground operations – both hard rock and coal – as well as in the opencast environment, plants and warehouses.

“Since our inception in 2006, safety regulations have changed significantly,” he says. “An important strength of our technology is that it has constantly evolved to meet the needs of the industry.”

The company now has a footprint of over 100 mining customers in South Africa, and this Namibian project is part of its gradual expansion into other countries in Southern Africa. He highlights that collision avoidance systems are likely to become increasingly mandatory in neighbouring states as these countries usually follow South African regulations. Major miners are also driving change through the globally recognised EMESRT guidelines.

“The International Council on Mining and Metals is also an important stakeholder in this process,” Lourens says. “The ICMM highlights that transport and mobile equipment accidents were highest cause of fatalities at their members’ operations in 2018, accounting for 30% of fatalities.”