IPR REBUILD GIVES UNRELIABLE WATER PUMP NEW LIFE

When a leading company in the petrochemical sector lost patience with the lack of reliability of a trailer mounted water pump, Integrated Pump Rental delivered a cost effective solution: refurbishment.

The water pump’s constant breakdowns meant that an intervention was required, but budgets were constrained. When consulted, Integrated Pump Rental was able to offer the option of either a completely new trailer mounted Sykes diesel driven pump or a refurbishment that would include fitting a new Sykes pump-end. 

To make the decision, the pump was stripped and assessed in Integrated Pump Rental’s modern workshop in Jet Park. After discussion with the customer, it was agreed to conduct a complete refurbishment, as the diesel engine driving the pump was also underperforming – further disrupting the pump’s operations at critical times.

Andre Strydom, rental development manager at Integrated Pump Rental, explains that in any refurbishment, it is vital to match the customer’s on-site duty requirement with the pump’s technical capacity. 

“In this case, 220 litres per second needs to be pumped at a head of 35 metres, and the decision was made to replace the pump-end with a Sykes CP250i with a 355 impeller which would the reliable delivery of a maximum flow rate of 280 litres per second,” Strydom says. “At a total head of 55 metres, the Sykes CP250i diesel driven pump can still manage a flow of around 100 litres per second.”

The engine was replaced with a Kirloskar 4K1080TA diesel unit which was close coupled to the Sykes CP250 pump-end, together with the dropped discharge pipework. 

An acid wash was used to clean off old paint and rust, while all non-working parts were stripped down to the fuel tank and chassis. Mechanical improvements were also made to the trailer and included a new hand-winch installed to lower the A-frame for easier coupling and uncoupling from the tow vehicle. Strydom says the fitting of this winch system will also reduce the risk of injuries, such as lower back strains or feet being caught when the trailer is unhooked.   

The turnkey operation was completed by Integrated Pump Rental in a quick turnaround time and within the customer’s limited budget, without compromising on quality. The complete rebuild – including delivery to site – took less than a month to complete. 

Strydom says Integrated Pump Rental also conducted the commissioning of the refurbished unit on the customer’s site. 

SANDVIK TECH CENTRE IN HARARE BOOSTS MINES’ DIGITAL JOURNEY

Sandvik Mining and Rock Solutions’ newly launched Technology Centre in Harare, Zimbabwe, is assisting the region’s mining industry on its exciting journey into the digital future. 

The centre has already begun working with technology-focused customers in underground hard-rock mines locally to raise the productivity bar. According to Sandvik Technology Centre manager, Hosea Molife the facility’s key aim is to use digital technology to make mines safer and more productive. 

“Our starting point was an Optimine implementation for the monitoring and tracking of underground mobile equipment and customer support for a MySandvik project,” says Molife. 

He explains that hardware is installed on the equipment together with the software to gather and transmit operational data, allowing mine management to view equipment location and productivity at any time. The data is automatically analysed giving the customer decision making dashboards. 

Ian Bagshaw, Sandvik Mining and Rock Solutions territory manager, says the technologies employed by the company essentially ‘take the lid off’ the mine, revealing vital real-time information such as tons mines and holes drilled. The Technology Centre can make use of various Sandvik solutions to render the data useful to the customer. These include MySandvik for equipment monitoring using up-to-date information, Optimine for integrating resources and optimising processes and Automine for automating mining activities.

Bagshaw highlights that the Sandvik Technology Centre has been welcomed by technology-focused customers in the region, who believe that this direction is an important differentiator. 

“These customers are certainly leading the way globally in the platinum mining sector,” he says. “There is  a strong safety element in the digital journey, as machine automation can help keep operators away from the workface and other potentially hazardous areas of the mine.”

There are already three projects underway at the Technology Centre, says Molife. The MySandvik solution is being provided to 100 machines on one site, while Optimine is being installed on a 76 unit fleet and Automine is initially being used to create a trucking loop for a single unit pilot project.

“The beauty of our facility is that it can be quickly ramped up as demand grows, allowing us to serve a growing customer base as mines see the practical value of applying digital technology,” he says. There has been considerable interest expressed by the region’s mines to date, with potential projects for the Technology Centre emerging in South Africa, Botswana and possibly further afield . 

According to Bagshaw, applying Sandvik’s digital solutions is the beginning of a  journey for mines, as they move away from paper-based and static data platforms. 

“In addition to installing the hardware and software to generate real-time data for mines, we also work closely with customers on how best to utilise the reports ,” he says. “Building these reports into their daily operations and real time decision making will bring the productivity value add.” 

ELECTRICAL INSTALLATION BY ZEST WEG AT PLATINUM EXPANSION

Zest WEG is installing a range of electrical control and instrumentation equipment at Anglo American Platinum’s Mogalakwena mine in Limpopo province, working closely with engineering group DRA Global. 

The construction is taking place within the Mogalakwena mine’s existing North Concentrator Plant, around various plant areas. The Electrical Control Instrumentation (ECI) package is being led by Eben Kleynhans, E&I electrical project engineer from DRA.

According to Calvin Fisher, electrical and instrumentation construction proposals manager at Zest WEG, the Zest WEG work is being conducted for the mine’s Coarse Particle Rejection (CPR) plant, and will be completed in the second half of 2021. 

“In addition to applying the highest level of workmanship and professionalism, we are carrying out the project in line with our client’s Mining Charter requirements on local procurement,” says Fisher. “This means that over 70% of people involved in our scope of work will be drawn from local communities, and we are sourcing a significant level of our supplies from local businesses.” 

Equipment to be installed includes three 2MVA transformers, stepping down from 11kV to 550V, and a 630kVA mini substation for lighting and small power requirements. Containerised Motor Control Centres (MCCs), complete with Variable Speed Drives (VSDs), an HVAC unit, cable racking, cables, lighting and small power also form part of the scope of supply. In addition, two backup generators will be installed – one of 630kVA capacity and the other 330kVA.

“The three new containerised MCCs and VSD sets will be placed on plinths near the CPR feed tank, CPR process water area and CPR building and a steel roof structure erected over the containers,” he says. “The new transformer bay will be constructed next to the MCC, also with a roof over the transformer.”

About 70km of cable will be laid – ranging from low voltage to medium voltage cable – as well as 3300 terminations and almost 2,5km of cable racking. The various structures that Zest WEG will install require some 9 tonnes of steel. The instrumentation to be installed will comprise about 170 instruments including flow transmitters, pressure gauges, level switches, temperature gauges and density transmitters. There will also be around 250 lights installed, mainly outdoors.

Fisher notes that the electrical installation specialists are typically among the last contractors on a project, and must be quite flexible to accommodate certain modifications that may have been required in the civils, structural and mechanical work completed beforehand. 

“Wherever necessary, we work closely with the client to implement the plan smoothly while meeting their need for safe access to the equipment being installed, to allow maintenance to be readily conducted,” he says. 

In addition to the installation contract, Zest WEG is supplying some of the actual items of equipment for the expansion project, including WEG motors and containerised generators. The electrical installation work is expected to take about six months. 

“We are proud of the high level of quality that we bring to projects like this, where we apply our successful model of procurement to support our clients in meeting their critical local expenditure targets,” he says. “This also allows Zest WEG to make a valuable contribution to uplift local companies wherever we can.”

READYMIX QUALITY KEY TO CONSTRUCTION SUCCESS

It is no surprise that cost cutting is the order of the day in the construction sector, but this should not prevent contractors from ensuring that their readymix concrete is up to scratch.

“The manufacture and supply of readymix needs to meet not just customer expectations, but also a range of regulated standards,” says Amit Dawneerangen, construction materials general manager for sales and product technical at AfriSam. “Our experience at AfriSam – where we are regularly asked to step in where a supplier has failed to meet obligations – suggests that it is time to go back to basics.”

The basics in the readymix sector, says Dawneerangen, involves an intricate balance of meeting South African National Standards (SANS), while delivering product at a competitive cost. These SANS requirements cover the manufacture of readymix, and the properties of the input materials. Complying with these standards implies that readymix providers have the necessary systems in place and equipment installed for accurate monitoring of concrete performance. 

He notes that South Africa has, over the past two decades, moved away from on-site batching towards greater use of readymix which can be produced at larger, centralised plants under highly controlled conditions. This gives contractors better assurance of quality levels, and allows the evolution of specialised and complex concrete mixes for challenging applications.

“The sophisticated technology used by many South African readymix producers underpins their compliance with the necessary standards,” he says. “For instance, there needs to be accurate weighing equipment in the batching plant, and systems to alert management if tolerances are breeched.”

This equipment must be calibrated regularly – internally and externally – to ensure accuracy. The standard SANS 878 specifies the tolerances within which the manufacturing and application of readymix must take place. For cement itself, there is SANS 50197 which applies, while standards for aggregate and sand are governed by SANS 1083.

Dawneerangen points to the growing number of ‘independent’ readymix companies who are not formally linked to the producers of construction materials like cement and aggregate. The difficult conditions which have prevailed recently in the construction sector has made it difficult for many to sustain themselves and cost cutting is affecting product quality. 

He emphasises that contractors need to carefully examine the quality systems in place at any prospective readymix provider before finalising procurement contracts. Without the assurance that these systems are being effectively applied, a contractor can expose their projects – and their business as a whole – to a range of serious risks. 

MULTOTEC DRIVES PROCESS EFFICIENCY, SOLUTIONS WITH IN-HOUSE TEST WORK

New mines or expansions rely on accurate test work to know how best to recover the minerals in an ore body; mineral processing specialist Multotec not only provides the processing solutions, but can also test material to inform clients’ financial and operational planning.

In a recent presentation to the South African Institute of Mining and Metallurgy (SAIMM), Multotec process engineer PJ Pieters and R&D engineer Jeantelle Rust outlined how the company’s extensive test work capability was put to use by industry.

“The process starts with accurate sampling – a field in which Multotec has developed a depth of expertise and a dedicated product range,” says Rust. “We prepare samples from clients with techniques such as filtration, drying, particle size distribution analysis and laboratory-scale float and sink analysis. We can also conduct sample splitting and packaging before the analysis takes place.”

Serving an international client base, Multotec has done test work on minerals including but not limited to gold, coal, lithium, mineral sands, copper, iron ore and tin. The work is carried out and supported by experienced metallurgists and product specialists. 

“Our expertise in physical separation allows us to test the samples using selected products from our portfolio, and ensures that the client gets the most effective solution,” she says. 

Test capabilities include gravity concentration using spirals as well as cyclones, magnetic separation, solid-liquid separation and water treatment related to metals recovery. 

“Accurate screening is also important, so our test facilities include Vibramech and LuCoTec vibrating screens to identify the best solutions to increase plant capacity, reduce wear and energy consumption, and optimise reagents,” says Pieters. 

There is also a trommel screen testing facility to provide insight into sizing or the removal of oversize material. Screening deck optimisation using deck maps helps clients find the best combination of open area and durability. The breadth of capability has led to many interesting tests being run, he says. 

While most test work is conducted at Multotec’s dedicated research and testing facilities, the company is also able to take certain equipment to a client’s operation for on-site testing to be done.

“This is a convenient way to conduct testing under normal plant operating conditions,” he says. “This kind of test work adds confidence to the client’s decision to invest in a specific solution.”

“These tests range from liners for bauxite and magnetic separation for wollastonite, to using cyclones to separate cow manure from grass and grit for use as a biofuel,” Rust says. “Testing with spirals has also helped clients find the best separation methods for material as varied as tantalite, wolframite and crushed computer components.”

Multotec’s test work feeds valuably into product development, continuously and cost effectively improving the company’s offerings based on its own R&D combined with client requests. The solutions can often be turned around much quicker than expected, using rapid prototyping with 3D printing and CNC machining powered by specialised modern software.

“Our test work has allowed us to modify cyclones, for instance, for innovative applications like removing plastic from sand or to vary cyclone inlet head geometries and ratios,” she says . “It has recently led to solid-liquid separation developing a South African-manufactured filter press.”

DATA CENTRE SURGE DEMANDS MORE DRY-TYPE TRANSFORMERS

Noting a marked increase in the demand for dry-type transformers for data centres being built in South Africa, Trafo Power Solutions will supply four 1600 kVA units to yet another data centre in Gauteng.

The country is benefiting from a wave of data centre investments in African countries including Kenya and Nigeria, according to a recent Standard Bank report. The trend is driven by advances in connectivity and data consumption, as smartphone use on the continent grows rapidly. Download speeds are rising which, in turn, boosts data consumption. There is also a global shift – driven by factors like data protection regulations – towards hosting data closer to where it is ultimately consumed.

Trafo Power Solutions managing director David Claassen highlights that data centres are energy-intensive, and need high levels of electrical power. In this context, the appropriate transformers with requisite protection devices are vital to support applications as robust as these. 

“Dry-type transformers are ideal for data centres, especially from a safety, reliability and environmental perspective,” says Claassen. “In addition, the load characteristics need to be considered. To suit the high percentage of non-linear or harmonic load, for instance, these transformers have a design K-factor of 13.”

The units were manufactured to the highest level of quality by TMC, a leading Italian transformer OEM, with whom Trafo Power Solutions has partnered to bring dry-type transformers to the African continent. These low-loss transformers conform to the European Directive EU 548-2014, providing considerable savings in energy consumption. An electrostatic shield is an important element of the design, diverting leakage currents to ground. 

“With our experience in dry-type transformer installations around Africa, Trafo Power Solutions are well equipped to assess the application requirement in data centres,” Claassen says. “In conjunction with our manufacturing partner, we can design and deliver a fast-track solution to meet the end-user’s specific needs.”

It is likely that new undersea cables to Africa will continue to raise broadband capacity, driving the trend for more data centres to be established locally.

CONCOR’S INNOVATIVE PAARL ROCK SHOWS THE WAY

Construction is underway at Paarl Rock, the fifth building in Concor’s 22-hectare Conradie Park development in Cape Town.

Piling for the eight-storey block began in May 2021, marking the start of a one-year building programme, according to Mark Schonrock, property development manager at Concor. Paarl Rock will comprise 266 architecturally designed apartments in an affordable model for first-time home owners. 

The block is underpinned by 158 continuous flight auger (CFA) piles, which present a quicker solution than bored or driven piles. With depths of 8 to 11 metres, the piles could be completed in just three weeks, Schonrock says, improving the pace of the project. 

“We have also installed two tower cranes – a 55 metre jib and a 45 metre jib – to facilitate our programme of work,” he says. These will lift and move concrete for vertical columns, as well as reinforcing bars for slabs and columns, and all formwork around the site.

Horizontal concrete slabs will all be post-tensioned, a current efficiency trend which reduces the amount of costly rebar required. The planned slab thickness has also been slightly reduced, from 285 mm to 255 mm. While a relatively small reduction, this will allow a saving of some 450 m3 of concrete over the planned area of 15,000 m2 of slab work.

“Pouring of slabs will be conducted by a truck-mounted boom placer, which enhances construction efficiency especially where large continuous pours of 200 to 220 m3 are required on this project,” he says.

The Paarl Rock block will include ground floor retail space, two lifts and a roof top deck on the sixth floor looking westwards at Devil’s Peak and over the Cape Town central business district towards Signal Hill. To minimise the cost of long-term maintenance on the outside walls, the design makes use of face brick – but with a difference. 

“Different colours and shapes of face brick have been specified to create texture and variety in the façade,” he explains. “Patterns are also created with rustication, using bricks of different shapes or with varied orientation.”

A perforated design is also used for the brick walls in front of drying yards, letting through light and air while also giving an attractive texture to the building façade. The laying of face bricks requires a somewhat elevated level of skill and attention, and also takes longer, so the best artisans are put onto the rustication work.

Schonrock notes that Cape Town still offers a good pool of bricklaying skills, but the long period of depressed conditions in the sector is going to be felt in skills supply as building activity improves. As part of its corporate contribution to skills development, Concor conducts a range of training on its Conradie Park site. 

“Through the National Youth Service programme, for instance, we are training six local bricklayer learners,” he says. “Beginning in November 2020, they completed a six-month training course and were then placed with selected sub-contractors to work on the current project.”

Paarl Rock’s innovations include an energy-efficient hot water system for residents, lowering their cost of living and taking load off the national grid. 

A centralised hot water generation system on the ground floor raises the upfront cost but provides many long-term benefits to users. An on-roof solar generator will assist in ‘over-heating’ water during the day in a specially-designed storage vessel to around 85 to 90 C. 

“Tapping into off-grid power in this way means that residents can save on what they pay in water-heating bills,” he says. 

The development is also conserving water and reducing water costs by supplying its own irrigation needs from a master incoming line of treated effluent – at just five to 10% of the cost of potable water. The water quality from this line, which is clean enough to be discharged into river systems, is further treated on site and also used for all irrigation and cleaning purposes.

Concor has been on site at Conradie Park – where the old Conradie government hospital closed about a decade ago – for about two and a half years, preparing the infrastructure for the developments. 

Roads have been installed, along with stormwater drains and a dedicated sewage reticulation system. A pump station was installed to move sewage over the Elsie’s River canal to the main Athlone sewer system and three new electrical substations were constructed.

The Conradie Better Living model is one of seven ‘game changer’ projects which has been prioritised by the Western Cape Government. This aims to improve the lives of citizens through the Finance Linked Individual Subsidy Programme, providing affordable housing situated near the city’s main arterial routes and job opportunities.

ADMIXTURES TO REDUCE CONTRACTORS’ CARBON FOOTPRINT

A new range of admixtures from CHRYSO will further support South African contractors in their efforts to transition towards a low-carbon economy.

The new CHRYSO® EnviroMix range of tailor-made admixtures allows for reduced environmental impact from concrete mix designs. While CHRYSO® EnviroMix delivers a reduction in CO2 emissions of up to 50%, CHRYSO® EnviroMix ULC (Ultra Low-Carbon) can achieve reductions of even more than 50% in the carbon footprint of concrete. 

A key feature of this admixture range is that it allows better utilisation of mixes that incorporate high volumes of pozzolans such as fly ash. It is able to achieve this while still ensuring superior levels of technical performance. Among other important benefits are an improved quality of concrete – due to a lower water-cement ratio for a given workability – and increased early and ultimate compressive and flexural strengths.

As part of this offering, CHRYSO also supplies customers with dedicated services such as EnviroMix® Impact. This allows the environmental impact of a concrete mix design to be calculated, so that formulation strategy can be set up for the customer to meet their specific carbon-reduction targets. CHRYSO also offers a digital solution for real-time monitoring of CHRYSO® Maturix concretes, which provides on-site concrete temperature, strength and maturity, humidity and climate monitoring.

The last 15 years has seen CHRYSO strengthening its expertise in the field of concrete admixtures with low-carbon impact. The innovative technology in the company’s portfolio of cement additives underpins its specialist knowledge in the chemistry of new low-carbon cements. Its solutions are based on many scientific collaborations and industrial partnerships, reinforcing its expertise in these new binders including geopolymers and calcined clay cements.

The CHRYSO® EnviroMix range also provides superior finishability, while improving surface quality and reducing cracking potential. The admixtures provide better workability and pumpability of concrete, as well as ease of placement and consolidation. 

Through these innovations, CHRYSO is developing solutions that produce the cements of tomorrow, as industry stakeholders search for technological opportunities to forge a low-carbon future.

LINATEX WEAR RESISTANT RUBBER LINING CUTS COSTS AT SENTINEL

Weir Minerals’ Linatex® Premium Rubber and Linard® 60 have significantly improved wear life at Kalumbila Minerals Limited’s Sentinel mine in Zambia, after the Weir Minerals Africa team was asked to provide a lining solution that would last longer than the incumbent product. 

To date, the Linatex® and Linard® solution has achieved six times the life of the product previously installed at Sentinel Mine. The competitor rubber product was no match for the high impact and abrasive nature of the 4,500 tph of slurry being fed to the mill discharge chute. 

The competitor rubber lining was failing after two months, resulting in downtime and added costs for equipment hire and specialised personnel. The remote location of the site also made obtaining materials for repairs a challenge. 

The Weir Minerals Africa team specified a double-layered rubber lining solution. A bottom layer of 30mm Linatex® Premium Rubber was selected to improve impact absorption, due to its resilient properties. Linard® 60 with a thickness of 25mm was selected for the top layer, due to its cutting and tearing resistance to the product reporting to the discharge chute. 

Weir Minerals Africa’s technical lining manager ensured the order was delivered to the customer site timeously. Together with a team from the Weir Minerals Zambia branch, the lining of the parts took place during a scheduled plant shutdown.

The combination of 30mm Linatex® Premium Rubber and Linard® 60 has lasted for one year with little to no signs of wear. This is a 250% wear life improvement when compared to the competitor product. As a result, Sentinel Mine has experienced reduced downtime and benefitted from the associated cost savings and with the increased plant availability maintenance personnel have been freed up to focus on other problematic areas in the plant.

Sentinel Mine has a longstanding relationship with Weir Minerals, with a range of Weir Minerals products installed and serviced over many years. With this in mind, the mine was confident that the team would provide an effective solution. 

Linatex® Premium Rubber is a proprietary vulcanised natural gum rubber, produced through a unique liquid-phase compounding process using high quality natural latex. It exhibits outstanding strength, resilience and resistance to cutting and tearing, giving superior performance in wet abrasion conditions.

CLEVER SOLUTIONS, RIGHT EQUIPMENT SAVES RE-MINING PROJECT

When a project to re-mine stockpiles at a large iron ore operation discovered its planning assumptions had been too optimistic, Pilot Crushtec was able to save the day with its experience and its ready fleet of Metso crushing equipment.

The plan was initially to feed natural fines – less than 8 mm in size – from run-of-mine (ROM) stockpiles to the smelter, later introducing a mobile jaw crusher and then mobile cone crushers with a sizing screen. It was found, however, that the portion of fines in the stockpile was much less than expected, putting the whole project in jeopardy. 

To rescue the situation, a fully mobile three-stage crushing and screening plant was urgently required to meet the required tonnages. Crushing and screening specialist Pilot Crushtec, who is also the local distributor of Metso equipment, had the answer and was able to deploy the necessary equipment on site within a few weeks. This included a Metso Lokotrack LT106 mobile jaw crusher, two mobile cones crushers – a Metso Lokotrack LT200HP standard and an LT200HP Short Head – and a Metso Lokotrack ST4.8 triple-deck mobile screen.

This was not the end of the challenges, though, as it soon became apparent that the concentration of iron within the stockpiled ore was lower than believed. Fortunately, the natural fines were richer than anticipated, presenting the opportunity of blending them with the lower-grade crushed ore. Here the Metso ST2.8 screen proved to be the key, with its two-way split providing a consistent supply of iron-rich natural fines to be blended with the stockpiles where required. 

The next step was to find ways of improving production of minus 8 mm material, although the 150 tonnes per hour being achieved was already regarded as good. With Pilot Crushtec’s experience, supported by Metso’s Bruno simulation software, a further increase of 10 to 15% was targeted. The strategy involved a range of complex ‘tweaks’ including an optimised liner profile, a change in screening media and apertures, and splitting the process train. 

This delivered the production target, with better continuity in the process while ensuring that the first two stages of crushing were not constrained by bottlenecks in the tertiary crushing and screening stage. This also reduced fuel and wear costs, as the equipment in the first half of the train could produce the same amount of material in fewer hours.