Monthly Archives: December 2021

Client Focus

TRAINING MECHANISED OPERATORS ENTERS VIRTUAL AGE

Virtual reality, simulation and mock-ups are among the range of learning platforms that the Murray & Roberts Cementation Training Academy (MRTA) is using to raise the bar in training operators of mechanised equipment. 

The impact of these enhanced training techniques is not just improved safety and productivity in mining operations, but also a business cost awareness, says Tony Pretorius, education, training and development (ETD) executive at Murray & Roberts Cementation. 

“Our unique approach to training mechanised operators takes the process well beyond the regulated requirements,” says Pretorius. After covering the psycho-motor skills, induction, legal and technical skills, and the relevant standards and procedures of the mine, MRTA takes an innovative approach to the more practical elements of the training. For instance, learners are placed in a virtual environment to assess the condition of equipment, followed by videos which show how this equipment operates in the workplace and how it is to be inspected. 

“They then progress to the use of simulators, where we can monitor three main areas of proficiency: health and safety; machine appreciation; and productivity enhancement,” he says. “The academy’s selection of simulators for this purpose includes the Sandvik DD321 drill rig, the Sandvik DD311 bolter, the Sandvik 514 load-haul dumper and the Sandvik 517 dump truck.”

He notes that a compact, mobile and immersive virtual reality drill rig simulator has also been introduced, allowing learners to experience a range of tasks. These include accurate indexing according to surveyed positions, different face conditions and various drill and blast patterns. It also simulates emergency triggers, and highlights where the operator’s drilling behaviour is sub-standard, showing the consequences of this for boom and drilling consumables. 

“Operators can also receive feedback simulations, where the cost of consumables and operational disruptions are explained,” he says. 

The learners can then be introduced to the mock-up environment at MRTA, where they can have the real experience of machine operation in a confined space. Here, they are required to demonstrate applied capability in emergency preparedness, machine inspections and brake tests as well as machine set-up and operations. 

“What is important for all operators to understand is how their behaviour impacts on mine costs and productivity,” says Pretorius. “This is one of the key areas where our interventions distinguish us in the training space.”

He says only after this intensive preparation are the learners placed in a workplace where they can progress to the required applied competency levels in a safe manner. 

Client Focus

CONCOR PROGRESSES WITH MAJUBA ASH DISPOSAL FACILITY

Leading black-owned contractor Concor is over halfway with extending the continuous ash disposal facility (ADF) at Eskom’s Majuba power station near Amersfoort in Mpumalanga. This project will ensure that Majuba can continue generating electricity while complying with ever-stricter environmental regulations regarding the responsible storage of waste.

According to Mabandla Dlamini, contracts director at Concor, the extended ADF will accommodate ongoing ash generation at the power station until February 2036. The project is being conducted in a fully-integrated joint venture with Midrand-based contractor Lubocon Civils, with an 85%:15% split with Concor holding the major percentage.

To date, Concor has handed over Terrace 2A and is in the process of handing over one of the two rehabilitation dams, says Dlamini. The construction of the extensive terraces – which measure 1.2 km long by 175 metres wide – began with bulk earthworks, cutting down to a design level before constructing the various layers. 

These layers include 100 mm of filter sand, followed by a Class 2 geomembrane and two 150 mm layers of clay. This is covered by a double-textured 1.5 mm HDPE geomembrane, followed by a 300 mm coarse ash layer. Each liner terrace, constructed from stabilised ash, is broken down into compartments of 5 metre widths, located every 100 metres.

“Underneath these layers, we are constructing a network of herringbone subsoil drains with a leachate collection system which will flow into a pollution control dam,” Dlamini says. “This will drain into Pollution Control Dam 5.”

Specialist sub-contractors have been used for the all-important lining beneath the dams, as well as the identification of any potential leaks in this lining. 

“The excavation and bulk earthworks for the pollution control and rehabilitation dams is followed by the construction of a subsoil drainage layer,” he says. “In addition to the geomembranes and layers of filter sand and impermeable clay, this layering includes 250 mm thick geocells, a ballast layer comprising 300 mm thick cement-stabilised sand (8% by mass) and geocells.”

The rehabilitation dams also have penstocks and valve chambers. Enhancing the environmental controls are water perimeter canals around the whole facility to separate and channel clean and dirty water. These are lined with 100 mm geocells filled with 30 MPa concrete, controlling the stormwater in the area. 

“The canals play a vital role in reducing the risk of any washdown from the tailings facility,” he says. “Measuring up to 7 metres in width, the total combined length of these canals will amount to more than 4 km.”

Some 1,400,000 m3 of earth is being excavated during the project, while the linings include 860,000 m2 of double-textured 1.5 mm high-density polyethylene (HDPE) liner. The stabilised ash layer will require 130,000 m3 of ash sourced from the power station and screened to prescribed specifications before being mixed with stabilising cement.

For the concrete work – which will include structural concrete for silt traps, spillways, drains and culverts bases – a total volume of 14,000 m3 of concrete will be used. Some 7,700 tonnes of cement will be delivered in bulk, to be stored in Concor’s on-site silos at its batch plant.

Site agent, Muhammad Asmal says that at project peak there will be almost 90 items of earthmoving equipment on the site. This will include 40-tonne articulated dump trucks, 70-tonne tracked excavators, tipper trucks, pug mills, screening equipment, graders and compaction equipment. 

“There are 43 subcontractors and suppliers engaged in the project,” Asmal says, “with over 440 personnel employed on site – 285 of them from local areas.”

The Concor-Lubocon JV is also constructing 5.5 km of internal or monitoring road, with G5 and G7 layers from commercial sources in Newcastle and Ermelo respectively. 

“As part of Eskom’s commitment to supplier development and localisation, a Supplier Development Plan was developed in conjunction with the Concor Lubocon JV to facilitate the inclusion of SMEs and QSEs from various towns surrounding the Majuba power station,” Nielesh Maistry, Eskom projects manager, says. “This included areas in the Gert Sibanda Municipality. “

SD&L manager, Nkateko Rasimphi highlights that the Concor Lubocon JV takes a proactive role in the training and induction of small and medium-sized enterprises (SME), especially with regard to issues such as legal liability, hazard identification and risk assessment.

“We have identified local technicians who we will help to develop, with the objective of training them and putting them on the road to professional registration,” he says. “The JV also runs a corporate social investment programme with local communities, focused on educational infrastructure in previously disadvantaged schools.”

Complying with strict environmental regulations means ongoing monitoring on site, according to Portia Rasakana, Lubocon’s environmental manager at the Majuba project. She highlights waste management as a key focus to avoid any environmental impact, but concerns such as pollution and dust management also receive constant attention.

“It is crucial that all our employees and subcontractors are conversant with the conditions of our Environmental Management Programme and our Water Use Licence,” says Rasakana. “This means building awareness among all our partners, and following up with strict enforcement.”

She notes that alien vegetation is also a concern, especially in areas where ground is disturbed. Management plans are in place for all environmental issues including waste, water and hazardous materials, she says. 

Client Focus

BUSINESS AS USUAL AS KWATANI/SANDVIK TRANSACTION CLOSES

Business as usual is how Kim Schoepflin CEO of Kwatani describes the news of the closing date of the transaction whereby Sandvik Rock Processing Solutions and Kwatani signed an agreement for the multi-national Sandvik Group to acquire the shares of this 45-year-old leading vibrating screen and feeder Original Equipment Manufacturer (OEM). 

Schoepflin says when the exciting transaction, which was subject to regulatory approvals and customary conditions, was made known to the mining and materials handling industries earlier this year it was exceptionally well received by the markets, from both potential and existing customers. 

“Kwatani has operated its world class production facility in South Africa for more than 45 years, and both Sandvik and Kwatani are technology leaders so bringing our combined resources to customers will be of enormous benefit,” she says. 

“What is most significant for the South African industry is that the collaboration is aligned with our government’s industrialization strategy. Furthermore, Kwatani is known for its commitment to compliance with the South African Mining Charter and we are a proudly Level 2 B-BBEE company.” 

Add to this, and a game changing move for the South African economy is that the Kwatani facility is set to become the global engineering and manufacturing base for vibrating screens and feeders for both local and international customers. The internationally recognised Kwatani brand, with its promise of being engineered for tonnage, will remain unchanged and the Kwatani brand will continue to be used across Africa while products sold internationally will be sold through the Sandvik sales channels under the Kwatani product name.

Schoepflin says that also exciting for the market is that Sandvik will further develop the Kwatani vibrating equipment brand globally. “This will see increased access to the Kwatani product through Sandvik’s global distribution network and customers will benefit by having access to a vastly increased customer service network.”

“Sandvik will also, through its global technology resources, provide access to monitoring and automation processes as well as access to its extensive R&D facilities which include simulators.” 

This, Schoepflin says, will provide opportunities for driving efficiency arising from the advance of artificial intelligence in the Fourth Industrial Revolution and will significantly empower the process of cost effective customisation. 

About Sandvik Rock Processing Solutions 

Sandvik Rock Processing Solutions, one of four different business areas in the Sandvik Group, is a leading global supplier of equipment, service and technical solutions for the mining and construction industries. Its products and solutions are specifically used in crushing and screening, quarrying and breaking and demolition application. 

About Kwatani 

Kwatani is Africa’s leading Original Equipment Manufacturer (OEM) of custom-engineers vibrating equipment including screens and feeders to both local and international customers. This South African based company, with a proven track record of 45 years, operates a world class production facility in Johannesburg. 

Client Focus

GRUNDFOS PUMPS KEEP UP PRESSURE IN NEW ROSEBANK BLOCKS

To reliably serve the water needs at three recently constructed multi-story apartment buildings in Rosebank, Johannesburg, ACS Consulting Engineers has installed a range of the latest pumping solutions from Grundfos.

Reaching heights between 10 and 22 floors, the three buildings required domestic water reticulation, hot water production and drainage solutions, according to Willem Strydom, senior design engineer at ACS Consulting Engineers.

“The domestic water supply throughout the buildings required pressure boosting due to the building heights and insufficient municipal pressure,” says Strydom. “A break tank in the basement of each building was used to disconnect municipal pressure – and will also limit the impact of any water outages.”

In terms of the system design, Grundfos vertical multi-stage booster pump sets were installed to transfer water from the basement tank to a secondary roof storage tank. This increases the storage capacity during water outages, while boosting pressure due to the geodetic height of the roof tank.

“A second Grundfos booster pump set – with its suction connected to the roof tank – was then situated in the basement plant room to supply hot and cold water throughout the building,” he explains.

Water heating is achieved by heat pumps in one of the buildings, and gas boilers in other two, with open hot water tanks used as ‘batteries’. For this application, Grundfos TP hot water circulating pumps – which are vertical in-line units – circulate water from the tanks through the boilers and back to the tanks.

“This keeps a constant temperature of 55 to 60 degrees Celsius in the tanks,” he says. “Water is circulated from the hot water storage tanks through heat exchangers using Grundfos TPE pumps.”

These Grundfos TPE units feature an on-board variable speed drive incorporated into the motor, says Nick Pluck, associate sales engineer CBS South Africa at Grundfos. This allows for automatic or manual set-points to speed up or slow down the motor to achieve the required pumping duty.

“If the temperature drops, therefore, the pump can accelerate to maintain the necessary temperatures in the hot water supply system,” says Pluck. “Conversely, it runs slower as the hot water supply temperature to the building rises. This increases the energy efficiency of the system by reducing pump speed during low hot water demand periods.”

Thermostatic hot water balancing valves are used in conjunction with the hot water circulating pumps to increase effectiveness and efficiency of the circulating pumps. The contract also required a solution to the risk of flooding in the building basements, in the event of heavy rain or a leak in the water storage tanks, says Strydom.

“The underground parking basements, where the plant rooms are situated, are all well below the municipal sewer lines and could potentially be flooded by stormwater runoff or groundwater ingress,” he says. “Multiple sumps were therefore built, and we fitted these with Grundfos SL pumps – one duty pump and one standby – controlled with level switches.”

If water levels in the sump rise, the pump is activated and discharges water from the sump to a sewer. He notes that Grundfos pumps were also used to supply water to hydrants and fire hose reels, a regulated safety requirement in all buildings. In the tallest two buildings, pressure boosting was also required for this purpose, so vertical multi-stage Grundfos CR90 pumps were installed to pump water from the basement break tank. Regulations specify that buildings have one hydrant per 1000 m2 and one hose reel per 500 m2 with a flow of 20 litres per second at 300 kPa for one hydrant or 1.5 litres per second for three hose reels (0.5 litres per second per hose reel). This is required at the topmost hydrant or hose reel.

Strydom highlights the reliability of the Grundfos pumps as a key factor for his choice, as well as the wide selection of pumps for various applications.

“Combined with the user-friendly interface of the Grundfos product centre and its responsive sales team, this makes the selection of pumps for our designs much easier,” he says. “Grundfos also has above-average after-sales support in the industry, and is willing to assist with any pump-related issue.”

Pluck says the engineers have to ensure that the best pump is specified to the optimal system in order to meet the client’s expectations. In high-end apartments like those in these Rosebank buildings, residents always expect a high quality of services to be reliably delivered, he says.

Client Focus

TOUGH CONDITIONS CALL FOR GRINDEX DRAINAGE PUMPS

Tough pumping applications such as on mine and construction sites need a proven range of drainage pumps that are heavy-duty but offer low total cost of ownership – these characteristics have been well proven in Grindex units. 

The Grindex range of drainage pumps handle water with abrasive solids up to 12 mm in size, and with high pH values from five to eight. Distributed locally by authorised southern African agent Integrated Pump Technology, Grindex submersible pumps have a heritage going back over 60 years – with more than 400,000 pumps delivered.

Drainage pumps are most suitable when users need to pump large quantities of dirty water, but still need to achieve heads of up to 200 metres, or flow rates of up to 350 litres a second. These Grindex pumps deliver all that, and convenience besides. 

This is according to Integrated Pump Technology sales manager, Jordan Marsh who say the unique valve on Grindex drainage pumps enables air cooling of the motor so they can run dry without a problem – and therefore don’t need babysitting.

On the small end of the range – comprising the Micro, Milli and Mini models – these pumps are compact, lightweight and ultraportable. The Micro model’s low power consumption makes it ideal when running on a generator. The Milli looks similar to the Micro, but enables low suction down to only a few millimetres, thanks to the unique non-return valve. 

In the medium section of the Grindex range are the Minex, Minette, Minor, Major, Master and Matador. The revolutionary hydraulic design ensures high wear resistance and dramatically reduces any performance drop that may result from long-time wear. 

“With their internal starter, SMART motor protector and optional level regulator, these pumps provide fully automatic protection and control without the need for external starter,” Marsh says. “The soft starter means smoother motor acceleration, thereby protecting the pump while reducing equipment wear and mechanical stress.”

There are two large Grindex drainage pumps – the Magnum and the Mega. The Magnum is relied on for the toughest jobs, with high quality, reliable design combined with the ease of maintenance. Made of cast iron, the Mega is ideal for operating in deep excavations where very high-head pumping is needed. Designed to handle pH levels from six to 13, it can also be fitted with zinc anodes for extra protection.