SYKES PUMPS ARE THE SOLUTION FOR MINE DEWATERING IN AFRICA

Two Sykes XH150 trailer mounted pumps will soon be doing dewatering duty at a mine in Africa, supplied by southern African distributors Integrated Pump Rental based in Jet Park, Gauteng.

This range of diesel powered units is ideal for dewatering an open pit, offering characteristics that include high head and head flow, according to Lee Vine, managing director of Integrated Pump Rental.

Vine emphasises that even the best run mine sites can be plagued by expensive challenges if they do not effectively control groundwater ingress into the open pit.

“This can cause not only programme delays but could also adversely affect health and safety on site,” he says. “So, when addressing the need for dewatering, it is vital that contractors deal with a supplier that understands dewatering applications and is able to provide the correct level of technical assistance; this will ensure that the most efficient methods are selected for the demands of a specific site.”

The Sykes Xtra High Head pump set boasts automatic priming and solids handling, so it dewaters more efficiently and effectively; it also has one of the best shaft stiffness ratios of any automatic priming pump on the market.

“These are fully automatic priming pumps and can run dry for extended periods due to the oil bath mechanical seal assembly,” he adds. “The low fuel consumption makes them cost effective to use for extended periods for time when dewatering.”

The pumps – designed for robust and reliable performance with high volumes of water – have an established reputation for the fast and effective control and removal of sub-surface water, he says. They can be primed with long suction hoses and can manage suction lifts of up to nine metres.

The pumps can even operate in ‘snore’ condition, which accommodates fluctuating suction levels; the pump will snore until the liquid is available for the pump to fully reprime itself automatically.

SMALL BUT MIGHTY: ALWAYS ON THE RIGHT RACK

With the IPS 200i, Leuze electronic has introduced the smallest camera-based sensor on the market for compartment fine positioning with high-bay storage devices in single-depth storage. Available from Johannesburg based Countapulse Controls, this sensor offers some powerful advantages, among these its fast commissioning and simple alignment.

Speedy commissioning is one of the most powerful advantages of the Leuze IPS 200i sensor. This is accomplished using a web-based configuration tool and adjustments are made directly on the small camera-based device itself. Engineered for optimum user friendliness, an alignment system with feedback LEDs provides additional support.

Due to its clever and compact design, the Leuze IPS 200i only needs a small space on high-bay storage devices. This enables quick, easy and accurate compartment positioning in either small part container storage warehousing or in single-depth pallet high-bay warehouses.

Equipped with powerful, ambient-light-independent IR LED lighting, a single device can be used for the entire working range of up to 600 mm. A model with integrated heating is also available for use in refrigerated warehouses where temperatures go down to minus30 °C.

Ensuring optimum reliability under all conditions is managed by its integral monitoring system with a quality score which identifies diminishing reading capacity of the sensor early on. This reduces downtime and improves the availability and cost effectiveness of the sensing systems.

Countapulse Controls is the official southern African distributor for Leuze electronic’s range of sensing solutions and its team is able to provide technical input and support. This ensures that the most appropriate technology is applied to a given application.

ANDREW MENTIS PRODUCTS BEAT CORROSION IN WASTEWATER INDUSTRY

When wastewater travels through sewer lines, it can become anaerobic or septic (the dissolved oxygen can become depleted) as a result of the metabolic processes of microbes commonly found in the wastewater. Under anaerobic conditions, specific sulphate-reducing bacteria thrive and generate hydrogen sulphide (H2S) as a byproduct of their respiration.

H2S has a low solubility in wastewater and when it escapes from the wastewater and moves into the air, it is easily recognised by its characteristic offensive, rotten egg odour. It can also be responsible for severe corrosion problems and toxic conditions within wastewater conveyance and treatment facilities.

“Andrew Mentis manufactures a range of corrosion-resistant floor grating and handrailing in galvanised, 304 stainless steel, 3CR12 and fibreglass options that are ideally suited to the extreme conditions found in wastewater treatment plants. All products in these ranges are designed and engineered to suit situations where the strength to weight ratio is important, such as wastewater treatment plants,” Lance Quinlan, marketing manager of Andrew Mentis, points out.

“The water and wastewater industry encompasses the mechanical and chemical processes used to remove pollutants from wastewater, for reuse in the environment. These processes can create a slippery environment for operators and technicians, with vapours, water and chemicals creating slick underfoot and handhold conditions near large machinery and tanks,” he explains.

An emphasis on safety underpins the development of all Andrew Mentis floor grating and handrailing products. “Weakened handrailings and floor gratings, caused by corrosion and damp, can result in slips, trips or falls. In addition, due to the fact that broken handrailing or floor grating needs to be replaced, downtime is incurred, which negatively impacts on productivity,” Quinlan says.

Galvanising or using stainless or fibreglass in a wastewater treatment plant is not only a safe and cost effective option, but it does not compromise the aesthetics of the environment.

Andrew Mentis’ Rectagrid RS40 floor grating is manufactured using a pressure locking system pioneered by the company. The locking characteristics guarantee the structural integrity of the product and further enhance its integrity in a corrosive environment.

“The transversals on the floor grating are positively and permanently locked to the bearer bars and the locking method at the intersections is designed to use the full depth of the bearer bar when calculating loads. This attention to detail ensures that the load bearing capacity is top of mind when design and manufacturing is undertaken,” according to Quinlan.

Andrew Mentis’ stainless steel tubular handrailing is reputed for its corrosion and stain resistance qualities. “We have designed the stanchion base plates to allow moisture to drain from the stanchion itself, thus adding further credence to its corrosion-resistant benefits. These handrails are not only functional, but also resilient and durable,” he says.

The tubular handrailing system is complemented by a range of standard angles and matching accessories, with different bends and end closers adding to the versatility of the product. “Enhanced customer service was a driving factor, with the stanchions and bends forming part of a system of interlinking components that can be installed without the need for special tools,” Quinlan comments.

The stanchions are 42.9 mm diameter by 2.5 mm wall thickness specifications, and are also available in 3CR12 or 304 stainless steel polished to a satin finish.

“Both Rectagrid and Mentis handrailing were selected for the Zeekoegat wastewater treatment plant and other treatment plants in the industry. We believe that each application deserves individualised attention and as such we customise products to meet specific application requirements, within specified client timeframes,” Quinlan concludes.

SHAW CONTROLS FAST TRACKS UPGRADE AT AUTOMOTIVE COMPONENT MANUFACTURING PLANT

A wide-ranging upgrade of the electrical distribution network at a catalyst manufacturer’s plant near Johannesburg has been successfully – and speedily – completed by Zest WEG Group companies led by Shaw Controls.

According to Shaw Controls chief operating officer Bevan Richards, the work was efficiently coordinated between companies in the Zest WEG Group so that the contract could be fast tracked during a special weekend shutdown to minimise the production disruption at the facility.

“This major upgrade of the plant – which included the moving and replacement of 17 transformers and 22 medium voltage outdoor panels – had to be completed in just five days,” says Richards. “With careful planning and preparation, along with the close collaboration of the customer, we were even able to complete the job with a day to spare, allowing production to resume earlier than expected.”

To meet these demanding timeframes, Shaw Controls proposed and implemented a solution that involved an E-house – a prefabricated walk-in modular enclosure to house switchgear and auxiliary equipment – as well as two containerised substations, built in-house at the company’s ISO 9001 Bureau Veritas-certified manufacturing facility in Heidelberg.

The E-house was equipped with free-issue medium voltage switchgear from the customer, and the substations were each equipped with a 400 V main distribution board. These modular solutions allow for assembly and testing in the factory, where customers can view the build progress as well as witness the performance of the finished product before delivery is finalised.

“The medium voltage panel was installed, pre-tested, commissioned and the relays programmed before delivery,” he says. Once at the customer site, it was simply a matter of connecting the cables before getting the system ready to be re-energised.

“Part of our project management role was to develop the design and construction drawings, working in conjunction with the customer’s consulting engineer,” he says. “We brought in group companies WEG Transformers Africa (WTA) to provide two 3 MVA oil transformers that stepped down from 11 000 V to 400 V and EnI Electrical to conduct the on-site construction work, which included medium and low voltage supply, installation and termination of cabling.”

EnI Electrical received all equipment on site, undertaking substantial site preparation and pre-works prior to the plant shutdown. It then instituted a two-shift system of 12 hours each over the project period, while Shaw Controls was on-site providing overall project management. On the first day of the shutdown, with the assistance of a mobile 250 tonne crane, EnI Electrical was able to remove all the old equipment and place the new items in position ready for cabling to begin. Access to the work area was also constrained, requiring the crane to reach over an existing building.

By the end of the project, 380 metres of 11 kV cable had been laid, with two cable joints and seven terminations, as well as 1 560 metres of 400 V cable with 21 joints and 132 terminations.

“A turnaround as fast as this is really only possible due to the utilisation of the E-house and containerised substation option,” he says. “Delivering all the equipment in loose pieces and building everything on site, as well as the necessary re-testing, would take much longer and would involve considerably more production downtime for the factory.”

The new system was designed by Shaw Controls and the consulting engineer to give the customer a highly stable system with more flexibility in terms of how the loads are distributed to the plant.

Added benefits of the E-house solution for the customer are that they do not have to manage multiple service providers and suppliers in the various aspects of constructing a substation, says Richards. The process could be potentially complex, time consuming and expensive, especially when conducted in remote sites where access is difficult and infrastructure is weak.

GET WISE ABOUT USING VARIABLE SPEED DRIVES

The benefits of variable speed drives (VSDs) are making this technology a popular choice among users of electric motors; now, with the introduction of the WEG Insulation System Evolution (WISE®) to all WEG motor lines, customers have full assurance that all WEG motors are VSD-compatible.

“Not all standard electric motors are suitable to be used with VSDs,” says Fanie Steyn, manager rotating machines at Zest WEG Group. “The motor insulation systems are susceptible to insulation damage caused by the harsh switching frequencies and voltage peaks generated by VSDs.”

Steyn explains that VSDs use power transistors – typically insulated-gate bipolar transistors or IGBTs – for the switching process. To achieve the high frequencies necessary for switching, the transistors have to turn ‘on’ and ‘off’ to conduct current repeatedly at high speeds. This results in voltage pulses with a high dV/dt, or rate of voltage change over time.

“When squirrel cage electric motors are fed by these high frequencies, the voltage pulses – combined with the cable and motor impedances – may cause repetitive conditions of over voltage or voltage overshoots at the motor connection terminals,” he says. “This may degrade the motor insulation system and reduce the motor’s useful lifespan.”

To ensure that this does not occur in WEG motors, the WISE® insulation system has been developed through the use of enhanced materials in the production of the motor insulation. These materials include VSD‑compatible wire, insulation film, impregnation material and suitable cables.

WEG has also specially developed its LackTherm varnishes for the insulation systems of its electric motors, which are applied to the 99,9% pure copper wire during the enamelling process. These LackTherm varnishes have excellent dielectric strength, flexibility, hardness and chemical resistance, as well as strong adhesion properties.

During the impregnation process, the stator coils receive layers of high‑solid resins and water‑based coatings which are environmentally‑friendly and free from harmful solvents – as required by the ISO 14000 guidelines.

“This process allows any WEG motors to be used with VSDs, as the WISE® insulation system ensures that the motor windings are protected against voltage peaks and voltage variations,” says Steyn.

WEIR BOOSTS CAPACITY AND FOOTPRINT IN AFRICA, MIDDLE EAST

Process solutions is now the focus of Weir Minerals Africa, as it works to bring its growing range of services and products closer to customers in Africa and the Middle East.

According to Gavin Dyer, Regional Managing Director of Weir Minerals Africa, the company is investing continuously in both physical and human resources – building its footprint of branches and service centres across the continent, while drawing in process engineering skills to bolster its capacity to optimise plants.

His new leadership team of experienced experts are driving the company’s sales and service focus, to bring a wider range of offerings closer to the market and ensure that the business is solidly customer-focused. With Marketing Director Rajen Govender driving the strategic marketing effort and handling the relationships with key customers, William Cumming focuses on the ‘home ground’ and most neighbouring countries, as Sales Director for South Africa and SADC.

Sub-Saharan Africa from Zambia upwards – and also the Middle East – is the jurisdiction of Pieter Jordaan, Sales Director for the rest of Africa. The company’s process department is headed by JD Singleton; as Process Director, he manages the over-arching process engineering offering that will add value at service centre, branch and mine site level across the geographic footprint.

“The work of this team will raise the profile of the wider product range and ensure that customers are achieving the best possible returns from this technology,” says Dyer. “There are still areas where Weir is known largely as an original equipment supplier in the field of slurry pumps. Our new structure and capacity will help alert customers to the many opportunities available from Weir Minerals Africa to improve plant efficiencies and performance.”

Singleton highlights the process division’s growing capacity to provide a complete process solution. Weir Minerals Africa’s services and products span a range of mine processes from the run-of-mine tip to the tailings dams, including equipment such as crushers, pumps, cyclones, linings, hoses, conveyors and valves. This positions Weir Minerals Africa increasingly as a total solutions partner rather than a mechanical engineering company focused on pumps.

“We have engaged more process engineers in our team, and with these skills can optimise mine operations from pit dewatering and jaw crushing, right through to screening, process functions within the mill, and even tailings disposal,” he says.

Another key aspect of the current strategy is to build on Weir Minerals Africa’s extensive footprint in Africa and the Middle East, allowing better responsiveness to customers’ needs.

“Our growing branch and service centre network provides the necessary springboard for the process engineers to get access to customer sites quicker and more often,” says Jordaan.

The strategic placement of more engineers now gives customers the opportunity to have site evaluations and plant audits more readily, says Cumming. By providing services like condition monitoring and better inventory strategies, unplanned breakdowns can be avoided and downtime reduced.

In a significant step into the world of e-commerce, Weir Minerals Africa customers have for the past year had easier access to its large range of spare parts, thanks to the online Weir Africa Store. By registering on the store at https://weirafricastore.com, customers can browse, search and order from the stock of Warman®, Cavex®, Linatex® and Trio® product spares. The purchase process is simple and parts can be collected or delivered within 48 hours; payment can be made easily by electronic funds transfer or even by credit card.

WEBA CHUTES PROVIDE SOLUTION AT CARMEN DE ANDACOLLO IN CHILE

Weba Chute Systems has successfully engineered a new transfer point to replace an underperforming chute at Carmen de Andacollo in the Coquimbo region of Central Chile.

Carmen de Andacollo is an open pit copper operation; Teck owns a 90% interest in the mine with Empresa Nacional de Mineria holding the balance of shares.

The new chute system transfers material from a double deck screen feeding oversize material from both decks to a conveyor. Material throughput is 2 000 tph with a lump size of minus 85 mm.

Alwin Nienaber, technical director at Weba Chute Systems, explains that in the previous installation the manner in which material was being presented onto the conveyor was causing impact damage and excessive spillage. The spillage had to be controlled using extremely hard skirtings under such tension that this had been causing extreme damage to the conveyor resulting in frequent belt replacement.

“It is not uncommon for us to see this type of issue which arises from inadequate plant design,” Nienaber says. “When the transfer points do not receive the requisite attention during the design of the plant, numerous problems can occur during operation.”

As a transfer point specialist, Weba Chute Systems is a strong advocate of their involvement at the start of a project. “This approach ensures that the transfer points are engineered for the particular plant, with the advantage that material transfer will be optimised and wear and impact issues such as those found at Carmen de Andacollo could be mitigated from the beginning.”

Where operational plants experience issues with transfer points, Weba Chute Systems sends in its technical team to conduct a full design assessment.

According to Nienaber this is a critical step in the process as it will ensure that the solution provided takes all factors into account. He explains that the previous chute was essentially just a box structure and this was problematic as the material flow was not controlled and it directly impacted onto the conveyor from the screen. To add to this situation the receiving conveyor design was also compromised.

“We were able to design a new transfer point solution that would accommodate the shallow flow angle required in this application,” he says. “By custom engineering the chute we were also able to design it in such a way so as to feed the material onto the conveyor in the direction of belt travel. This then eliminated the issues associated with the previous direct impact.”

The design of Weba Chute Systems also allows for absolute control of the material and, in this application, has been configured to force a concentrated stream from the screen decks onto the conveyor. Due to the compromised general arrangement between the screen and conveyor, skirts are still required to eliminate spillage.

To provide further protection against sliding abrasion, the chute has been lined with high alumina ceramic tiles.

The Weba Chute Systems installation at Carmen de Andacollo was commissioned in the first quarter of 2017. Nienaber says that much of the work has been done through Weba South America which was established in Chile to service this region.

Under the leadership of Pedro Javier Vega, Weba South America has been making inroads into the mining and minerals processing sector. “The local team has a good understanding of the industry, its immediate and long terms needs, and will provide consistent support to this customer,” Nienaber says.

COMAR ASPHALT PLANTS GET EVEN MORE MOBILE

Leading the local industry in asphalt plants, Gauteng-based Comar has designed a more compact and mobile plant for easier and more economical transportation, as well as quicker set-up time.

Already a well-known name among South African asphalt producers, Comar has leveraged its extensive in-house design, engineering and manufacturing capacity to continually improve plant design, performance and energy efficiency.

According to Comar director Ken Basson, the new design is in line with international trends towards increasingly mobile and smaller configurations. He emphasises, however, that this does not mean sacrificing plant capacity.

Comar operations manager De Wet Dreyer says many mobile plants still require some components to be transported on low bed trucks and to be erected using on-site cranes; this is contrary to the customer need for greater mobility and ease of movement.

“We now have a fully mobile design, which consists of two units,” says Dreyer. “The first chassis carries the feed bins and the other the drum, bag house and other components. There is considerable market interest, and we are preparing our mobile plant design for manufacturing.”

The result is quicker installation, allowing the plant to be set up within hours, rather than taking a week or two as with traditional methods. Operation of the plant can then begin almost immediately.

“The design is very versatile,” he says. “The operation can be set up to discard directly into a truck, for those projects that only require 100 or 200 tonnes of production, or it can be parked and configured to feed into the standard Comar skip rail and 100 tonne hot storage facility for larger scale projects.”

Comar also upgrades and optimises existing asphalt plants by working with customers on their current operations to improve their performance. This is done by retrofitting or replacing components.

The company has also developed a number of ancillary products for its plants, such as bitumen storage facilities, bag houses, bitumen decanting systems, hot storage facilities, silos, screw conveyors, rotary valves and purpose-built elevators. It has even developed a bitumen spray cart.

The plants are automated and can be operated with a user-friendly plant interface controlled from an HMI touch-screen, putting all key plant parameters at the operator’s fingertips.

Basson emphasises the after-sales support Comar offers, with dedicated service teams staffed by qualified mechanical engineers being on call to attend to customers’ equipment on site. Comar’s designs also prioritise the use of locally available components so that maintenance or repairs are not delayed by waiting for parts to arrive from abroad.

RFI KEEPS PACE WITH FAST-MOVING DIESEL INJECTOR TECHNOLOGY

As regulations on carbon emissions around the globe lead original equipment manufacturers (OEMs) to improve the environmental performance of their products, diesel injector technologies are advancing apace, and Germiston-based Reef Fuel Injection Services (RFI) is staying at the cutting edge.

With the recent installation of its second Hartridge test bench, RFI has boosted its capability and can now calibrate the new generation smart Delphi diesel injectors.

“We align ourselves closely with the OEMs in each of our diesel injector lines, so that we can offer a remanufacturing process that is officially certified and gives the customer the peace of mind that their remanufactured unit will last as long as a new one,” says RFI director Andrew Yorke.

What comes out of the OEM-approved repair process is an injector with the same quality and specifications as a new injector from that OEM, says Yorke. Other diesel fuel injection systems for which RFI is an authorised service agent include Bosch, Denso and Stanadyne. All RFI’s repairs are backed by an OEM warranty, and the company also handles warranty claims on behalf of the OEM dealers. RFI is acknowledged as the market leader for the repair of CAT fuel injection systems.

“The new Hartridge bench is part of our ongoing new investment to keep up with world class technology, will double our capacity to repair, remanufacture, test and calibrate Delphi diesel injectors,” says Yorke. “It will also allow us to serve the growing market in Delphi systems, as this brand expands beyond its traditional application in light motor vehicles to larger truck engine applications,”

Yorke says that the remarkable progress of injector technology – while being driven mainly by the global drive to reduce emissions from diesel engines – also brings cost related benefits to customers, including higher efficiencies and lower fuel consumption for end users from the Delphi smart fuel injection system.

“The higher pressures that are being built into modern injection systems produce better atomisation and contribute considerably to the efficiency of the combustion cycle – which in turn improves engine efficiency and diesel consumption rates,” he says, reminding users that it makes economic sense to ensure that all diesel that is put into an engine is properly burnt.

In an interesting illustration of the advances that have taken place in recent decades, the latest Delphi systems are designed to operate with a 2,500 bar injection pressure; this compares with the 240 bar pressure that was normally associated with original mechanical injectors.

Yorke emphasises the importance of the electronically controlled nozzle control valves in the latest smart injector systems, allowing multi-stage injection cycles that further raise burn efficiency within the combustion chamber.

“For RFI, it is part of our mission to stay ahead of the game across the range of fuel injection systems in the market today,” says Yorke, “as the vehicle population in South Africa is fairly small by European or North American standards.”

Remanufacturing diesel injectors – a cost effective option to the replacement with new parts – always requires testing and calibration before a unit can be returned to a customer in an ‘as-new’ condition.

“With access to OEM software, we can generate trim codes that we can feed into the Engine Control Unit (ECU) of the diesel engine, controlling the combustion cycle to achieve best performance results,” he says.

A further advantage of the company’s level of equipment and expertise is that – while generic testing is done using only four test steps – RFI conducts this procedure through 20 or more test steps in an environment that replicates the operating conditions of the engine.

To support customers’ need for quicker repair turnarounds – especially in the long distance and heavy haulage transport segment where downtime is costly – RFI offers a service exchange programme. Remanufactured fuel injectors and fuel pumps are made available for immediate installation, while RFI undergoes the lengthier process of assessing, analysing and remanufacturing the damaged units, reducing the likely interruption to customers’ operations.

Established in 1975, RFI is a subsidiary company of Metric Automotive Engineering, also a well-respected and leading player in the remanufacture of diesel engine components.

BOLTED THICKENERS ARE THE FUTURE – FLSMIDTH

The concept of bolted thickeners is growing in popularity. According to FLSmidth senior account manager Ricus van Reenen, this is a fit-for-purpose, high quality dewatering solution with reduced project construction risk and duration.

These benefits resulted in FLSmidth securing an order in July 2017 for a 24 metre diameter high-rate thickener from a South African iron ore mining company.

“Although this concept has been around for at least a decade, it is becoming more commonly used,” says van Reenen. “With a bolted tank, the whole thickener is constructed inside a purpose-designed fabrication facility with all welding, sandblasting and painting taking place under controlled conditions. This guarantees that everything fits as it should so there are no unexpected delays on site.”

Thickeners have traditionally been constructed on site; all rolled and bent plates are transported to the required location where they are welded onto the prefabricated support structure and radial beams.

“This process can take weeks to complete, as there are kilometres of welding runs required,” he says. “Moreover, the considerable weight of the material in the finished tank – several thousand tonnes – means that the weld quality needs to be high and coded welders must conduct the work.”

These welders often have to be accommodated on site for extended periods of time, which adds to the cost; cross-border work often involves the added burden of obtaining work permits and special visas for these workers.

Sandblasting of the welding runs is then necessary, as well as a final coat of paint. In addition to the extra costs, the work is highly weather dependent and delays can be caused by rain or excessive dust.

“Weather related delays can cause time over-runs for the contractor, which can then lead to penalty costs,” he says. “This sort of project risk is one of the main reasons why contractors are choosing bolted thickeners. As a contractor, your time on site is where your most significant risk will lie.”

After the construction of a bolted thickener in a workshop, the whole tank can be transported to site where the bulk of the on-site work can be undertaken by a mechanical supervisor, who oversees the lifting and placement with the support of a rigger and a crane driver. Local labour can be used to fit the necessary bolts into the structure, and a technical specialist can come in to torque the bolts.

“Once in place, only touch-up painting is required, so poor weather won’t be a serious risk factor,” says van Reenen. “Ensuring that deadlines are met means on-time commissioning, which aligns well with FLSmidth’s role as productivity partner to mining projects.”

He notes that FLSmidth has supplied at least 20 projects globally with bolted thickener tanks, putting close to 40 of these units into the market in recent years. The largest unit was a 45 metre diameter high-rate thickener, while the more specialised deep cone thickeners have also been built in this way up to a size of 35 metres in diameter.