WEBA CHUTE SYSTEMS SIGNS UP DISTRIBUTOR IN CANADA

Weba Chute Systems has announced the appointment of FWS Bulk Material Handling as the official distributor of Weba Chute Systems and Solution in Canada. The signing of this latest licence agreement underpins the South African OEM’s strategy of extending its global reach.

Mark Baller, managing director of Weba Chute Systems, says that the synergy between the two companies bodes well for a successful long term partnership. Weba Chute Systems was founded more than 50 years ago and has since become the world’s leading provider of custom engineered transfer point solutions.

“FWS Bulk Material Handling has an equitable track record with its teams spread across Western Canada, and the extensive design-build experience within the company as well the knowledge of project execution across a broad range of industries played a major role in our decision to enter into a formal agreement,” Baller says.

Notably, Weba Chute Systems has previously supplied its custom engineered chute systems to the North American market where these have been used in the power generation and mining sectors. Baller says that while the company has a sound understanding of the needs of this region, it is also looking forward to working closely with FWS Bulk Material Handling in services other sectors including agriculture, bulk storage and export terminals, food processing and railways.

“Years of experience, hard won expertise and skill are the major differentiators that allow Weba Chute Systems to produce transfer point systems engineered specifically for a given application requirement,” Baller says.

“Our transfer points are definitely not off-the-shelf products and while anyone can do the basics when it come to the technical side of designing a transfer chute, it is not an exact science and there is simply no single solution for materials transfer.”

Weba Chute Systems has more than 4500 transfer point systems successfully operating in countries across the world. The company operates a comprehensively equipped manufacturing facility at its South African based head office, and this is underpinned by its team of skilled and competent engineers.

MULTOTEC BRINGS VALUE OF SPIRALS TO MORE MINERALS

Experience in the field and in its test laboratory has allowed Multotec Process Equipment to prove the economic impact of applying spiral concentration technology to high value minerals used in cellular phones and electric cars.

“A number of customers mining minerals such as copper, lithium, tin and tantalite are already benefiting from using spirals to upgrade the value of their concentrate, either replacing their conventional processing technique or augmenting it,” says Graeme Smith, application engineer at Multotec Process Equipment.

Smith highlights the likely growth in the demand for these kinds of minerals, in line with the mass production of various electronic devices and the imminent prospects for electric car manufacture. Lithium is important to battery production, tantalite is used in resistors and capacitors, and copper and tin are key contributors to electroconductivity.

He says that spirals are proving their worth in helping producers become more efficient, potentially raising output levels while holding down the cost involved in downstream processing. This upgrading of the value of mined material also contributes to lower transportation costs and higher revenues earned.

Recent successes have been enjoyed by copper mines in the Democratic Republic of Congo, Zambia and Zimbabwe, where Multotec’s spirals are upgrading product from 1-3% run-of-mine to 20%-plus copper concentrate.

“These mines can achieve an upgraded product which can be sold as copper concentrate,” he says. “Spirals can also be applied as a bulk reduction strategy to achieve a higher-grade material for more efficient leaching.”

Working with tin producers in countries including Morocco, the DRC and Spain, Multotec spirals have been able to raise initial head grades of 1-3% to levels of over 50% tin in concentrate. Treating tantalite from a tailings operation in the DRC, spiral technology has performed massive bulk reduction and upgrading, while shaking tables clean the final product.

“This allows existing downstream processes to become more productive, and to ramp up production by maximising recoveries and reducing rand per tonne costs,” he says.

In test work in its extensive Spartan manufacturing and research facility near Johannesburg, Multotec has also succeeded in separating elements of lithium using spiral technology, aiming for 80% concentration of the element petalite.

Smith emphasises the value of the company’s experience in modular plants, allowing spiral applications to be conveniently containerised for transport to and commissioning at remote sites.

“Our mobile plants – capable of treating 20 tonnes per hour – can be moved in two standard containers – one of 12 metres in length and the other of 6 metres,” he says.

COMMODITY-WIDE SUCCESS FOR KWATANI SCREENS

The recent orders won by vibrating screen and feeder specialist Kwatani have cemented its reputation as the leading South African original equipment supplier (OEM) with a truly cross-commodity footprint.

Kwatani’s custom engineered products are now in some of the world’s largest mines, and many customers have standardised on their screens to ensure lowest cost of ownership and high performance, according to general manager sales and service Jan Schoepflin.

“While our base and core market are in Africa, the global demand for Kwatani products has grown rapidly. A leading diamond mining company in Russia is very pleased with Kwatani screens at their newest operation and specified Kwatani for future projects,” Schoepflin says.
In another order from a large diamond operation, this time in South Africa, the customer also replaced the last of their competitor screens with a Kwatani unit Schoepflin say this is because they have enjoyed years without unplanned stoppages by using Kwatani screens. “It has shown that our equipment and service are just as effective in unusually harsh climatic conditions.”

At a local brownfield diamond expansion project, the company’s multi-slope banana screens were matched to the available plant footprint, raising throughput from 250 to 500 tonnes per hour and later breaking the mine’s tonnage record.

While screening in heavy minerals is Kwatani’s stronghold, the company has moved extensively into coal, supplying the country’s leading coal producer with no fewer than 45 items of large screening equipment, including out-sized 4,3 metre wide units. Other recent coal-related orders included run-of-mine screens for a medium-sized coal mine in Mpumalanga. Again, competitor equipment was replaced by custom designed screens with optimised deck angles which significantly increased tonnage. The positive results achieved with the Kwatani equipment also led to additional orders for the mine’s expansion.

For world largest zinc mine, Kwatani was contracted to supply all the screens for the world’s largest zinc mine. At Africa’s largest iron ore mine, the company has recently completed two projects, renewing existing equipment with up-to-date solutions and replacing 24 items of competitor equipment.

The platinum sector is also keeping Kwatani busy, not just in South Africa but over the border in Zimbabwe too. A recent turnkey solution focused on the platinum by-product chromite, where the company supplied a complete solution which included feeder, dryer and screen to treat chromite of 45 micron size at 15 tonnes per hour.

“Our screens have been a popular choice for modular gold plants going to West Africa as well as Central and South America,” he says. “We also supplied to two of Africa’s largest copper producers in Zambia, to a tanzanite producer in Tanzania, and repeat orders to a manganese mine in Ghana.”

HOW THE REFLUX™ CLASSIFIER INCREASES MINING PRODUCTIVITY

Delivering high levels of recovery, while managing large throughput efficiently is no easy job. So how exactly does FLSmidth’s REFLUX™ Classifier (RC™) achieve this? And, importantly, can it benefit your mining operations?

Concisely, the RC is the slurry based gravity separator designed specifically to upgrade fine minerals generally finer than 2mm. The key design element is a system of lamella plates or inclined channels and the internal overflow launders. These are contained within the Lamella Settler – the top portion of the RC. The other two main components are an Autogenous Dense Medium Separator underneath the lamella chamber, and a Fluidised Bed Separator beneath that.

Material from the process plant enters through the slurry inlet and passes over an internal over-size protection screen which removes any tramp or debris that may cause damage to the ceramic underflow valve. Large, high-density solids quickly sink and settle in the mixing chamber that is in the middle section of the classifier, forming a fluidised bed of dense material. The fluidised bed is created by a series of water jets at the base of the mixing chamber and rejects any trapped lighter particles.

Lighter and finer particles rise in the RC, through the autogenous zone to the lamella section. The autogenous section is created by fine suspended solids, and this zone helps convey lighter particles to the lamella section.

This upper section contains the crucial sloping lamella channels, that are typically placed 6mm apart – although this distance can be reduced for finer materials. Low density particles rise up through these channels, driven by the upward water flow from the feed. The narrow sloping channels cause a parabolic flow pattern, where the flow is fastest midway between the channel walls.

The lightest particles are carried by the faster flow before they can settle and they overflow at the top of the channel. They fall into internal launders and are discharged from the RC. The higher density particles tend to slide back along the topside of the lamella channel, where the flow is slower. These particles slide down the slope, back to form the autogenous dense media zone.

Pressure probes monitor the bed density and automatically control the underflow valve to optimise the bed level and density. The fluidised bed keeps particles in suspension and rejects the lighter material up out of the bed while the denser particles sink and flow out through the underflow valve. The valve’s four-link system moves the plug vertically, which reduces wear and provides protection against splashing.

In a recent innovation, a modular RC™ plant, FLSmidth carefully selected the associated equipment – like pumps, screens, dewatering equipment and conveyors – for optimal performance. These modular plants are also automated, using advanced instrumentation and control equipment to keep operations consistent and recoveries high.

DEBTECH X-RAY DIAMOND RECOVERY TECHNOLOGY TO SIERRA LEONE

Working in collaboration with project house Paradigm Project Management, diamond processing technology specialists DebTech is supplying its well-proven X-ray diamond recovery technology to the Tongo diamond mining project in Sierra Leone, currently being developed by Newfield Resources Ltd.

DebTech’s mature sorting technology is a dependable solution for high efficiency recovery of diamonds from a wide variety of kimberlite, marine and alluvial sources, capable of treating a material size range from 1 mm to 32 mm.

In this case, the dry unit – the CDX118CD – was specified for the West African project, featuring an eight-channel photo multiplier detection system capable of identifying all types of diamonds including low luminescence, yellow and boart.

“The appeal of the technology is its efficient diamond recovery with minimum gangue material, even at high feed rates,” says Gavin Alexander, products manager at DebTech. “These rates can range from 825 kilograms per hour with material sized between 1 mm and 2 mm, to 4,5 tonnes per hour with material of 16 mm to 32 mm in size.”

Among the benefits of the system are its unique “dual wavelength” detection system and small installed footprint. It is capable of self-testing, while calibration can be conducted on-line.

“Designed to be operator-friendly and straightforward to maintain, the unit offers complete operator safety due to its improved features,” he says. “It is specifically designed to enhance diamond security, and the compact sorting modules can be configured for higher throughput or for a double-pass process, as required.”

There are manual and automated inlet chute gate options available, with a robust air ejector system that ensures no loss of valuable stones. Design is modular, compact and ergonomic, with left and right-hand variants available to suit. The split cabinet design features a heat exchanger-cooled X-ray generator and power supply compartment with separate control and service panel configurations. There is a single network interface for control and information, and DebTech ensures there is full maintenance support for customers, wherever they are on the globe.

GROWING READYMIX MARKETS WITH CHRYSO TECHNOLOGY

Leveraging its admixture technologies and its growing range of value-added products, CHRYSO Southern Africa is helping its readymix customers expand their markets despite the flat conditions in the construction sector.

According to Deon Klopper, sales manager readymix segment at CHRYSO Southern Africa, the slow economy continues to pressurise readymix suppliers, but the answer lies in offering end-users more options to reduce their costs while delivering quality results.

“This is where the role of CHRYSO’s research and development efforts – leading to ongoing technology advances – is becoming so important to the readymix sector,” says Klopper. “Working closely with both the readymix supplier and the end-user, we ensure that we understand what both parties require.”

This allows CHRYSO to share information with end-users about a range of cost effective options, which they then purchase through the readymix supplier.

“End-users need to produce their concrete at a certain optimum cost per cubic metre to remain competitive, while retaining the required quality,” he says. “At the same time, readymix producers can use our value-added products to help grow their markets by offering more solutions to the end-user.”

CHRYSO Southern Africa has continued to expand its range to include technologies such as fibres, mould release oils, curing compounds, decorative concrete, permeability reduced watertight concrete and dust suppressants.

“While the readymix supplier was in the past expected just to deliver what the customer ordered, they can now offer their customers more, by servicing other site requirements and make useful cost saving proposals,” he says.

Among CHRYSO’s admixture developments, for instance, is CHRYSO® QUAD 20, which allows end-users to utilise lower grade sand, where sand and aggregate quality has become more variable. CHRYSO® Quad 20 is a unique formulation which increases the viscosity of cement paste with limited impact on concrete slump and slump flow.

He also highlights CHRYSO’s focus on providing fit-for-purpose solutions that suit the specific priorities of any given project.

“We ask customers what is most important in each of their projects – such as the concrete’s strength, slump or open time – and can then manufacture an admixture specifically for their readymix concrete,” says Klopper. “Our CHRYSO® Optima 1000 technology, for instance, represents a formula that adjusts to match customers’ demands, with unprecedented flexibility for maximum robustness, reliability and precision. It offers up to seven hour workability retention and up to 50% water reduction for an optimal dosage per cubic metre.”

LEUZE 10 SERIES OFFERS HIGH TOLERANCE TO DIFFERENT MATERIALS

Engineered with a high tolerance to different materials, the Leuze 10 Series optical sensors detects objects and measures distances with an incredible accuracy of +/-30 mm. Available from Countapulse Controls, these high performance sensors have an operating range of up to eight metres.

The high tolerance of the Leuze 10 Series sensors further extends to the angle of incidence, the colour, surface structure and brightness of reflective material. This enables the sensor to detect different materials, such as wood or matt as well as glossy metal, and this is possible even under varying environmental conditions.

The Leuze 10 Series is also suitable for sensing applications where deep black materials are found or where objects are not ideally aligned or where they are moving rapidly.

The highly visible status indicators on the devices makes for ease of use and the sensors also have large control buttons. The LED display has been designed to facilitate step-by-step commissioning and diagnosis at the press of a button.

The compact housing, with integrated recesses for M4 screws or nuts, means installation is possible in applications where space restrictions exist. However, its small size does not impact on the overall performance of the Leuze 10 Series.

A comprehensive range of Leuze sensing solutions is available from Johannesburg-based Countapulse Controls. The company can assess any sensing application and provide a fit-for-purpose solution to meet the specific needs of an operation. A 24/7 hotline is available to assist end users with technical challenges that may be experienced due to lack of knowledge or experience. For further information call 066 148 6287.

SAFETY FIRST WITH DURABLE MENTIS FLOOR GRATING

Liability claims from slips, trips and falls in the workplace can be financially debilitating and have an extremely negative impact on the reputation of a business. Considered the most frequent cause of injuries in the workplace, these incidents can result in serious downtime and even closure of facilities.

Floors, stairs and handrails are often cited as the cause of such accidents. In some incidents, injury is caused by factors beyond the reasonable control of the business owner. However, there is great wisdom in the adage ‘prevention is better than cure’.

Lance Quinlan, national technical sales consultant at Andrew Mentis, says that companies should consult floor grating specialists to ensure that their floor grating adheres to the required building regulations and occupational health and safety (OHS) standards.

He explains that unfortunately for the consumer, not all floor grating products on the market are of a suitably high standard. “An inferior quality product may well look identical to a reputed brand when viewed through the eyes of an unsuspecting customer. However, the real litmus test comes after the installation is completed and employees start walking on the floor grating.”

Quinlan cautions that customers should carefully research the claims made by the floor grating manufacturer. “Mentis floor grating is engineered to take specific loading which then ensures the optimum safety of the people walking on or working in those areas. We initially meet with customers to determine their exact needs, then our processing department compiles the layouts for the required products according to the structural steel drawings supplied by the customer. A complete understanding of the load bearing capacity of grating is required to ensure that the correct floor grating product is selected for an application.”

All Mentis floor grating is manufactured in a world class facility at Elandsfontein, Johannesburg using a pressure locking system pioneered by the company. “Quality control is stringent during the manufacturing process to ensure that close tolerances are maintained and that the round transversal bar fits tightly through the pierced bearer bar on our floor grating products,” he says.

Mentis has two predominant floor grating products – Rectagrid RS40 40/40 and Rectagrid RS80 80/40. RS40 40/40 is a premium brand and is formed through a process of compressive pressure locking of bearer bars and transversals to form an exact pitch of 40 mm by 40 mm. Rectagrid RS80 80/40 is identical to RS40 40/40 grating except that we omit every second bearer bar, giving an 80 mm pitch bearer bar with a 40 mm pitch transversal. This effectively reduces the RS80 80/40’s permissible load bearing capacity by 50%.

Quinlan emphasises that the most critical element is the load bearing capacity of the floor grating. “The best way to ensure the structural integrity of floor grating is to align yourself with a manufacturer who has designed and engineered the product to attain predetermined tolerances. Mentis is pedantic about the strict criteria set for its floor grating.”

Non-negotiable factors include the fact that the transversals must be positively and permanently locked to the bearer bars. “In addition, there must be no cracks or crevices at intersections which could harbour corrosion. The locking method at the intersections should be designed to use the full depth of the bearer bar when calculating loads. Finally, the grating panels should be flat, square and untwisted. Safety in the workplace simply cannot be compromised,” he concludes.

WEIR MINERAL’S CAVEX® HYRDOCYCLONE SHINES IN DIAMONDS

The successful performance of Weir Minerals’ Cavex® hydrocyclones at a diamond mine in South Africa’s Northern Cape Province has proved the technology’s applicability in dense medium separation (DMS) plants treating diamondiferous material.

In her presentation to the Southern African Institute of Mining and Metallurgy (SAIMM) diamond conference in Johannesburg in 2018, Weir Minerals Africa’s Senior Process Engineer, Boitumelo Zimba, said the hydrocyclones improved plant efficiencies and produced 40% more tonnage than the mine’s target.

“As the Cavex hydrocyclone is tried and tested in hard rock mining and coal classification, the Cavex 360° laminar spiral inlet profile was used as a basis for the development of a dense medium cyclone,” Zimba said. “Individual casting patterns were developed and produced in order to fabricate the Cavex dense medium hard chrome cyclone with the exact laminar spiral feed chamber that exists when moulded out of rubber.”

The customer required a solution that could offer at least six months wear-life, and a probable error of separation (Ep) of no greater than 0,08 at a cut density of 3,1 tonnes per cubic metre (t/m3). Tracer tests were used to monitor the efficiency of the separation achieved by the Cavex® hydrocyclones to ensure all of these requirements were met.

“Ep values achieved were 0,042 for the 4 mm tracer tests and 0,035 for the 8 mm tracer tests, which were below the set maximum target of 0,08 from the mine,” Zimba said. “This highlighted the benefits and improved efficiencies of the Cavex laminar spiral feed inlet.”

The lower the Ep – or probable error of separation – the more efficient the separation; it is defined as half the difference between the density at which 75% is recovered to sinks, and that at which 25% is recovered to sinks.

“The customer’s tracer tests on the Cavex hydrocyclones showed that cut points of 3,08 t/m3 were achieved for both the 4 mm and 8 mm tracers,” Zimba said. “This was within the performance levels of 3,1 t/m3 that the customer had specified.”

Initially, the hydrocyclones were commissioned to treat only fines at the diamond plant – the minus 8+1 mm material. Later however, the mine decided to run a combined DMS, after which the full DMS size range of minus 20+1 mm was treated through all the fines DMS hydrocyclones.

The unique design of the laminar spiral inlet geometry delivers sharper separation and maximises capacity while delivering a longer wear-life than conventional involute or tangential feed inlet designs. By providing a natural flow path into the hydrocyclone body the design allows the feed stream to blend smoothly with the rotating slurry inside the chamber, reducing turbulence and improving separation efficiency.

“Combining our cone and spigot components in the hard metal range is an important contribution to the reduction in turbulence,” Zimba explained. “Another vital factor is the Cavex inlet design with 360 degree scroll; this design was proven through extensive computational fluid dynamics (CFD) analysis as well as our multiple installations to date.”

Weir Minerals also conducts ongoing research and development on methods to minimise turbulence on assembled casted components. The Cavex® hydrocyclones are designed with a variety of inlet sizes to accommodate a wide top size at specified medium-to-ore ratios. The inlet sizes range from 0,2 to 0,33 as a function of the hydrocyclone diameter.

The Cavex® CVX hydrocyclone also has a wide range of vortex finder sizes to maintain separation efficiency at different operating yields and spigot sizes. The vortex finder sizes range from 0,4 to 0,5 as a function of cyclone diameter, and are designed to maintain a strong air-core at different spigot sizes.

To prolong life and efficiency, the hydrocyclones can also be manufactured with different materials. Cavex® CVXA hydrocyclones are hard-wearing and are cast in 27% chromium iron for maximum abrasion resistance; components are designed for ease of maintenance, with all surfaces joined with a layer of epoxy cement.

“Our focus on supplying best-in-class technology includes developing components that offer low wear rates,” said Zimba. “This is achieved by using a combination of materials with different wear rates in a range of hydrocyclone parts. This is made possible by our global technological expertise that allows us to cast components using various alloys, depending on the type and abrasiveness of the ore being treated.”

Weir Minerals Africa operates two foundries in South Africa – one at its Isando facility and the other at its Heavy Bay Foundry in Port Elizabeth. This allows the organisation to cast items in-house leveraging its local foundry personnel’s knowledge, experience and expertise, ensuring that the highest standards are maintained.

This approach ensures optimal life of the hydrocyclone in operation, and reduced maintenance costs by replacing worn parts in situ. It also eliminates the risk of any adverse effects on performance arising from mixing old and new hydrocyclone components. Further, safety on site is enhanced by minimising the maintenance work necessary on the installed hydrocyclones.

“Future work will include the investigation of various alloys to combat high wear rates on some of the hydrocyclone components, in particular the vortex finder and the cone sections,” Zimba said. “This will allow longer operation and plant stability.”

JOHNSON CRANE HIRE ROLLS OUT ITS OWN ‘BIG FIVE’

Customers of Africa’s lifting leader Johnson Crane Hire were recently treated to an impressive display of a selection of the company’s lifting equipment at an open day where its heavy lift fleet was likened to the ‘big five’ of the wild.

“Johnson Crane Hire is a home grown South African business, and like the big five we are firmly rooted in Africa,” Peter Yaman, sales executive at Johnson Crane Hire, says. “Just as the big five have adapted to their natural environment, so have we succeeded in adapting to our economic environment, which is not always easy.”

Yaman describes the company’s LR 750-ton crawler crane as the elephant in the fleet: “This is a brute of a crane, with the ability to lift over 100 African elephants at once – with each of these great beasts weighing five tons or more.”

Next in line is the LR 600 crawler crane, displaying the toughness of a buffalo. He notes that the buffalo is also the ultimate herd animal, reflecting the company’s focus on teamwork to get every job successfully and safely accomplished.

“The rhino is the creature that comes to mind when talking about our powerful Kobelco 400 ton crawler crane,” he says, “as they share the attributes of ruggedness, durability and stability.” At the same time, he notes, heavy lifting also requires speed, precision and agility – qualities that make the LTM 750 ton hydraulic mobile crane comparable to the leopard.

Last but certainly not least is Johnson Crane Hire’s LG 750 ton lattice boom crane, which Yaman compares to the lion – king of the Jungle and a force of nature and leadership.

“Leadership in safety and in lifting is what we are passionate about, being driven to attain ‘SMART’ lifting – through safety, maintenance, availability, reliability and total cost effectiveness – as our brand promise,” he says. “Of course, we also have our zebras and impalas in the form of our 20 ton and 30 ton cranes, as well as our access platforms.”

Ranked amongst the top crane hire companies in the world, Johnson Crane Hire operates the largest mobile crane fleet in Africa, with strategically located operations to ensure quick delivery and ongoing support to customers. Outside of South Africa, it is actively engaged in several African countries including Botswana, the Democratic Republic of the Congo (DRC), Mozambique, Zimbabwe, Lesotho, Swaziland, Namibia and Zambia.